Science.gov

Sample records for multiple band wireless

  1. Investigation of interference in multiple-input multiple-output wireless transmission at W band for an optical wireless integration system.

    PubMed

    Li, Xinying; Yu, Jianjun; Dong, Ze; Zhang, Junwen; Chi, Nan; Yu, Jianguo

    2013-03-01

    We experimentally investigate the interference in multiple-input multiple-output (MIMO) wireless transmission by adjusting the relative locations of horn antennas (HAs) in a 100 GHz optical wireless integration system, which can deliver a 50 Gb/s polarization-division-multiplexing quadrature-phase-shift-keying signal over 80 km single-mode fiber-28 and a 2×2 MIMO wireless link. For the parallel 2×2 MIMO wireless link, each receiver HA can only get wireless power from the corresponding transmitter HA, while for the crossover ones, the receiver HA can get wireless power from two transmitter HAs. At the wireless receiver, polarization demultiplexing is realized by the constant modulus algorithm (CMA) in the digital-signal-processing part. Compared to the parallel case, wireless interference causes about 2 dB optical signal-to-noise ratio penalty at a bit-error ratio (BER) of 3.8×10(-3) for the crossover cases if similar CMA taps are employed. The increase in CMA tap length can reduce wireless interference and improve BER performance. Furthermore, more CMA taps should be adopted to overcome the severe wireless interference when two pairs of transmitter and receiver HAs have different wireless distances.

  2. Fiber-wireless transmission system of 108  Gb/sdata over 80 km fiber and 2×2multiple-input multiple-output wireless links at 100 GHz W-band frequency.

    PubMed

    Li, Xinying; Dong, Ze; Yu, Jianjun; Chi, Nan; Shao, Yufeng; Chang, G K

    2012-12-15

    We experimentally demonstrate a seamlessly integrated fiber-wireless system that delivers a 108  Gb/s signal through 80 km fiber and 1 m wireless transport over free space at 100 GHz adopting polarization-division-multiplexing quadrature-phase-shift-keying (PDM-QPSK) modulation and heterodyning coherent detection. The X- and Y-polarization components of the optical PDM-QPSK baseband signal are simultaneously upconverted to 100 GHz wireless carrier by optical polarization-diversity heterodyne beating, and then independently transmitted and received by two pairs of transmitter and receiver antennas, which form a 2×2 multiple-input multiple-output wireless link. At the wireless receiver, two-stage downconversion is performed firstly in the analog domain based on balanced mixer and sinusoidal radio frequency signal, and then in the digital domain based on digital signal processing (DSP). Polarization demultiplexing is realized by the constant modulus algorithm in the DSP part at the receiver. The bit-error ratio for the 108  Gb/s PDM-QPSK signal is less than the pre-forward-error-correction threshold of 3.8×10(-3) after both 1 m wireless delivery at 100 GHz and 80 km single-mode fiber-28 transmission. To our knowledge, this is the first demonstration to realize 100  Gb/s signal delivery through both fiber and wireless links at 100 GHz.

  3. Antenna polarization diversity for high-speed polarization multiplexing wireless signal delivery at W-band.

    PubMed

    Li, Xinying; Yu, Jianjun; Chi, Nan; Xiao, Jiangnan

    2014-03-01

    We propose and experimentally demonstrate a novel architecture for a W-band integrated optical wireless system, which adopts a 2×2 multiple-input multiple-output (MIMO) wireless link based on antenna polarization diversity, and can realize 80 km single-mode fiber-28 transmission and 2 m wireless delivery for up to 39 Gbaud polarization-division-multiplexing quadrature-phase-shift-keying (PDM-QPSK) signal at 100 GHz. Classic constant-modulus-algorithm (CMA) equalization is adopted at the receiver to implement polarization demultiplexing. The 2×2 MIMO wireless link adopts one pair of horizontal-polarization (H-polarization) horn antennas (HAs) and one pair of vertical-polarization (V-polarization) HAs. Because the two pairs of HAs are fully isolated, the wireless cross talk can be effectively avoided. Thus, compared to the 2×2 MIMO wireless link at the same antenna polarization, the adoption of antenna polarization diversity cannot only make the HA adjustment easier but can also reduce the required CMA tap number. After removing 20% forward-error-correction overhead, the 39 Gbaud baud rate corresponds to a net bit rate of 130  Gb/s, which, to our best knowledge, is the highest bit rate per PDM channel demonstrated for wireless signal delivery up to now.

  4. Transparent data service with multiple wireless access

    NASA Technical Reports Server (NTRS)

    Dean, Richard A.; Levesque, Allen H.

    1993-01-01

    The rapid introduction of digital wireless networks is an important part of the emerging digital communications scene. The introduction of Digital Cellular, LEO and GEO Satellites, and Personal Communications Services poses both a challenge and an opportunity for the data user. On the one hand wireless access will introduce significant new portable data services such as personal notebooks, paging, E-mail, and fax that will put the information age in the user's pocket. On the other hand the challenge of creating a seamless and transparent environment for the user in multiple access environments and across multiple network connections is formidable. A summary of the issues associated with developing techniques and standards that can support transparent and seamless data services is presented. The introduction of data services into the radio world represents a unique mix of RF channel problems, data protocol issues, and network issues. These problems require that experts from each of these disciplines fuse the individual technologies to support these services.

  5. 40-Gb/s PDM-QPSK signal transmission over 160-m wireless distance at W-band.

    PubMed

    Xiao, Jiangnan; Yu, Jianjun; Li, Xinying; Xu, Yuming; Zhang, Ziran; Chen, Long

    2015-03-15

    We experimentally demonstrate a W-band optical-wireless transmission system over 160-m wireless distance with a bit rate up to 40 Gb/s. The optical-wireless transmission system adopts optical polarization-division-multiplexing (PDM), multiple-input multiple-output (MIMO) reception and antenna polarization diversity. Using this system, we experimentally demonstrate the 2×2 MIMO wireless delivery of 20- and 40-Gb/s PDM quadrature-phase-shift-keying (PDM-QPSK) signals over 640- and 160-m wireless links, respectively. The bit-error ratios (BERs) of these transmission systems are both less than the forward-error-correction (FEC) threshold of 3.8×10-3.

  6. Tri-band microstrip antenna design for wireless communication applications

    NASA Astrophysics Data System (ADS)

    Sami, Gehan; Mohanna, Mahmoud; Rabeh, Mohamed L.

    2013-06-01

    This paper introduces a novel rectangular tri-band patch antenna that is fabricated and measured for wireless communication systems. The introduced antenna is designed for WLAN and WiMAX applications. The desired tri-band operation was obtained by proper loading for a rectangular patch antenna using slots and shorting pins. The optimal location and dimension for the loaded elements were obtained with the aid of interfacing a Genetic Algorithm (GA) model with an Ansoft High Frequency Structural Simulator (HFSS). The results obtained from our simulated antenna show 5.8% impedance matching band width at 2.4 GHz, 3.7% at 3.5 GHz and 1.57% at 5.7 GHz. In addition, an equivalent circuit of the proposed antenna is introduced using the least square curve fitting optimization technique.

  7. Wireless Channel Characterization in the 5 GHz Microwave Landing System Extension Band for Airport Surface Areas

    NASA Technical Reports Server (NTRS)

    Matolak, David W.

    2007-01-01

    In this project final report, entitled "Wireless Channel Characterization in the 5 GHz Microwave Landing System Extension Band for Airport Surface Areas," we provide a detailed description and model representation for the wireless channel in the airport surface environment in this band. In this executive summary, we review report contents, describe the achieved objectives and major findings, and highlight significant conclusions and recommendations.

  8. Asymmetric acoustic transmission in multiple frequency bands

    NASA Astrophysics Data System (ADS)

    Sun, Hong-xiang; Yuan, Shou-qi; Zhang, Shu-yi

    2015-11-01

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices.

  9. Asymmetric acoustic transmission in multiple frequency bands

    SciTech Connect

    Sun, Hong-xiang; Yuan, Shou-qi; Zhang, Shu-yi

    2015-11-23

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices.

  10. Development of a Wireless Remote Monitoring System Utilizing Multiple Wireless Sensors

    NASA Astrophysics Data System (ADS)

    Masuda, Shinichi; Hattori, Tetsuo

    A novel remote monitoring system for all day outdoor observation using multiple wireless sensors and wireless communication (Handy phone and PHS) is proposed. The whole system consists of three parts: (i) a host station that is PC (Personal Computer), (ii) remote station that contains a camera controlled by CPU and power supply (battery attached by solar cell), and (iii) multiple wireless sensors having each ID signal. The remote station usually works by an event-driven method based on the wireless sensor signals. Because of this event-driven method, various multi-vision systems are easily configurable. This paper describes the details of the system and evaluates the possibility of the application of the system. Since some of the systems are now really running in many places, we can consider that the effectiveness of the system is shown by the fact in a practical sense.

  11. Performance of Multiple Pulse Multiple Delay Modulated UWB Signals in a Multiple Access Indoor Wireless Channel

    SciTech Connect

    Nekoogar, F

    2003-06-12

    In this paper, the performance of a two user UWB multiple access (UWB-MA) system based on multiple-pulse multiple-delay (MPMD) modulation scheme in an indoor wireless channel is evaluated by computer simulations. The indoor multipath propagation channel model used in this study is based on the modified statistical Saleh-Valenzuela model proposed by Foerester and Li from Intel. The simulation results indicate that the multipath performance of MPMD modulated signals in a multiple access system outperforms the nonmultipath case as the number of autocorrelation function (ACF) sampling points increases for each user. This is an unusual but important result, since MPMD receiver exploits multipath phenomenon in indoor wireless channels to increase the BER performance, hence the transmission rate in a UWB-MA system.

  12. 75 FR 17349 - Operations of Wireless Communications Services in the 2.3 GHz Band

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-06

    ... December 2007, the Commission released a Notice of Proposed Rulemaking, 73 FR 2437 (January 15, 2008) (NPRM... COMMISSION 47 CFR Part 27 Operations of Wireless Communications Services in the 2.3 GHz Band AGENCY: Federal...) seeks comment on revising the performance requirements for the 2.3 GHz Wireless Communications...

  13. Chiral geometry in multiple chiral doublet bands

    NASA Astrophysics Data System (ADS)

    Zhang, Hao; Chen, Qibo

    2016-02-01

    The chiral geometry of multiple chiral doublet bands with identical configuration is discussed for different triaxial deformation parameters γ in the particle rotor model with . The energy spectra, electromagnetic transition probabilities B(M1) and B(E2), angular momenta, and K-distributions are studied. It is demonstrated that the chirality still remains not only in the yrast and yrare bands, but also in the two higher excited bands when γ deviates from 30°. The chiral geometry relies significantly on γ, and the chiral geometry of the two higher excited partner bands is not as good as that of the yrast and yrare doublet bands. Supported by Plan Project of Beijing College Students’ Scientific Research and Entrepreneurial Action, Major State 973 Program of China (2013CB834400), National Natural Science Foundation of China (11175002, 11335002, 11375015, 11461141002), National Fund for Fostering Talents of Basic Science (NFFTBS) (J1103206), Research Fund for Doctoral Program of Higher Education (20110001110087) and China Postdoctoral Science Foundation (2015M580007)

  14. 160 Gbit/s photonics wireless transmission in the 300-500 GHz band

    NASA Astrophysics Data System (ADS)

    Yu, X.; Jia, S.; Hu, H.; Galili, M.; Morioka, T.; Jepsen, P. U.; Oxenløwe, L. K.

    2016-11-01

    To accommodate the ever increasing wireless traffic in the access networks, considerable efforts have been recently invested in developing photonics-assisted wireless communication systems with very high data rates. Superior to photonic millimeter-wave systems, terahertz (THz) band (300 GHz-10 THz) provides a much larger bandwidth and thus promises an extremely high capacity. However, the capacity potential of THz wireless systems has by no means been achieved yet. Here, we successfully demonstrate 160 Gbit/s wireless transmission by using a single THz emitter and modulating 25 GHz spaced 8 channels (20 Gbps per channel) in the 300-500 GHz band, which is the highest bitrate in the frequency band above 300 GHz, to the best of our knowledge.

  15. Adaptive Code Division Multiple Access Protocol for Wireless Network-on-Chip Architectures

    NASA Astrophysics Data System (ADS)

    Vijayakumaran, Vineeth

    Massive levels of integration following Moore's Law ushered in a paradigm shift in the way on-chip interconnections were designed. With higher and higher number of cores on the same die traditional bus based interconnections are no longer a scalable communication infrastructure. On-chip networks were proposed enabled a scalable plug-and-play mechanism for interconnecting hundreds of cores on the same chip. Wired interconnects between the cores in a traditional Network-on-Chip (NoC) system, becomes a bottleneck with increase in the number of cores thereby increasing the latency and energy to transmit signals over them. Hence, there has been many alternative emerging interconnect technologies proposed, namely, 3D, photonic and multi-band RF interconnects. Although they provide better connectivity, higher speed and higher bandwidth compared to wired interconnects; they also face challenges with heat dissipation and manufacturing difficulties. On-chip wireless interconnects is one other alternative proposed which doesn't need physical interconnection layout as data travels over the wireless medium. They are integrated into a hybrid NOC architecture consisting of both wired and wireless links, which provides higher bandwidth, lower latency, lesser area overhead and reduced energy dissipation in communication. However, as the bandwidth of the wireless channels is limited, an efficient media access control (MAC) scheme is required to enhance the utilization of the available bandwidth. This thesis proposes using a multiple access mechanism such as Code Division Multiple Access (CDMA) to enable multiple transmitter-receiver pairs to send data over the wireless channel simultaneously. It will be shown that such a hybrid wireless NoC with an efficient CDMA based MAC protocol can significantly increase the performance of the system while lowering the energy dissipation in data transfer. In this work it is shown that the wireless NoC with the proposed CDMA based MAC protocol

  16. Ku-band multiple beam antenna

    NASA Technical Reports Server (NTRS)

    Chen, C. C.; Franklin, C. F.

    1980-01-01

    The frequency reuse capability is demonstrated for a Ku-band multiple beam antenna which provides contiguous low sidelobe spot beams for point-to-point communications between any two points within the continental United States (CONUS), or regional coverage beams for direct broadcast systems. A spot beam antenna in the 14/21 GHz band which provides contiguous overlapping beams covering CONUS and two discrete beams covering Hawaii and Alaska were designed, developed, and tested. Two reflector antennas are required for providing contiguous coverage of CONUS. Each is comprised of one offset parabolic reflector, one flat polarization diplexer, and two separate planar array feeds. This antenna system provides contiguous spot beam coverage of CONUS, utilizing 15 beams. Also designed, developed and demonstrated was a shaped contoured beam antenna system which provides contiguous four time zone coverage of CONUS from a single offset parabolic reflector incorporating one flat polarization diplexer and two separate planar array feeds. The beams which illuminate the eastern time zone and the mountain time zone are horizontally polarized, while the beams which illuminate the central time zone and the pacific time zone are vertically polarized. Frequency reuse is achieved by amplitude and polarization isolation.

  17. Multiple walker recognition using wireless distributed pyro-electric sensors

    NASA Astrophysics Data System (ADS)

    Li, Nanxiang; Hao, Qi

    2008-04-01

    This paper presents a wireless distributed pyroelectric sensor system, whose sensing visibilities are modulated by Frensnel lens arrays and coded masks, for multiple human walker recognition. One goal of our research is to make wireless distributed pyroelectric sensor nodes an alternative to the centralized infrared video sensors, with lower cost, lower detectability, lower power consumption and computation, and less privacy infringement. In our previous study, we succeeded in identifying individuals walking along the same path, or just randomly inside a room, with an identification rate higher than 80% for around 10 subjects, only using one wireless sensor node. To improve the identification rate and the number of subjects that can be recognized, one-by-one or simultaneously, we employ multiple sensor nodes to leverage the performance of the distributed sensor system. The fusion of pyroelectric biometrics from multiple nodes is performed at four different levels: sample, feature, score, and decision. The experimental results show that the proposed pyroelectric sensor system has potential to be a reliable biometric system for the verification/identification of a small group of human objects. Its applications include security monitoring, human-machine interfaces, and virtual environments.

  18. Multiple human tracking with wireless distributed pyro-electric sensors

    NASA Astrophysics Data System (ADS)

    Li, Nanxiang; Hao, Qi

    2008-04-01

    This paper presents a wireless distributed pyroelectric sensor system, whose sensing visibilities are modulated by Fresnel lens arrays, for tracking multiple humans. The aim of this study is to design and develop a wireless infrared sensor system which can track multiple humans with better data-to-object association, lower power consumption/cost/detectability, and less privacy infringement than its infrared video-based counterpart. The concept of a geometric sensor is discussed and utilized in local/global visibility modulation for the node-centric sensor system, to implement the process of data-object-association, performed by a Bayesian joint probabilistic data association scheme with validation gates. An Expectation-Maximization-Bayesian tracking scheme, consisting of detection, localization, filtering, and prediction, is proposed and implemented among slave, master, and host modules of a prototype sensor system. Experimentally the prototype system was able to simultaneously track two individuals in both follow-up and crossover scenarios with average tracking errors less than 0.5 m. The proposed wireless distributed infrared sensor system can not only run as a stand alone inmate/patient monitoring system under all illumination conditions, but also serve as a complement for conventional video and audio human tracking systems.

  19. Multiple band structures of {sup 131}Cs

    SciTech Connect

    Sihotra, S.; Palit, R.; Naik, Z.; Joshi, P. K.; Deo, A. Y.; Jain, H. C.; Singh, K.; Goswamy, J.; Mehta, D.; Singh, N.; Malik, S. S.; Praharaj, C. R.

    2008-09-15

    Excited states in {sup 131}Cs were investigated through in-beam {gamma}-ray spectroscopic techniques following its population in the {sup 124}Sn({sup 11}B, 4n) fusion-evaporation reaction at a beam energy of 46 MeV. The previously known level scheme has been substantially extended up to {approx}9 MeV excitation energy and 49/2({Dirac_h}/2{pi}) spin with the addition of seven new band structures. The present level scheme consisting of 15 bands exhibits a variety of collective features in this nucleus at intermediate spin. The excitation energies of the observed levels in different bands and the corresponding ratios of transition strengths, i.e., B(M1)/B(E2), have been compared with the results of projected deformed Hartree-Fock calculations based on various quasiparticle configurations. A strongly coupled band has been reassigned a high-K three-quasiparticle {pi}h{sub 11/2} x {nu}(h{sub 11/2}d{sub 3/2}) configuration based on the properties of this band and that of its new coupled side band. The configurations of these bands are also discussed in the framework of tilted-axis cranking model calculations and the systematics of the odd-A Cs isotopes. Additional three energetically closely placed coupled bands have been assigned different unpaired three-quasiparticle configurations. {gamma}-vibrational bands coupled to the {pi}h{sub 11/2} and {pi}g{sub 7/2} single-particle configurations have been reported in this nucleus. Observation of new E1 transitions linking the opposite-parity {pi}h{sub 11/2} and {pi}d{sub 5/2} bands provides fingerprints of possible octupole correlations.

  20. Multiple triaxial bands in 138Nd

    NASA Astrophysics Data System (ADS)

    Petrache, C. M.; Ragnarsson, I.; Ma, Hai-Liang; Leguillon, R.; Zerrouki, T.; Bazzacco, D.; Lunardi, S.

    2015-02-01

    High-spin states in 138Nd were investigated by using the 48Ca+94Zr reaction and γ -ray coincidences were acquired with the GASP spectrometer. A rich level scheme was developed including 14 new bands of quadrupole transitions at very high spins. Linking transitions connecting 11 high-spin bands to low-energy states have been observed. Calculations based on the cranked Nilsson-Strutinsky formalism have been used to assign configurations to the observed bands. The main result of these calculations is that all 14 bands exhibit a stable triaxial deformation up to the highest observed spins, giving strong support to the existence of a triaxial minimum with normal deformation and positive asymmetry parameter in nuclei with a few holes in the N =82 shell closure.

  1. Propagation Characteristics in an Underground Shopping Area for 5GHz-band Wireless Access Systems

    NASA Astrophysics Data System (ADS)

    Itokawa, Kiyohiko; Kita, Naoki; Sato, Akio; Matsue, Hideaki; Mori, Daisuke; Watanabe, Hironobu

    5-GHz band wireless access systems, such as the RLAN (Radio Local Area Network) system of IEEE802.11a, HiperLAN/2, HiSWANa and AWA, are developed and provide transmission rates over 20 Mbps for indoor use. Those 5-GHz access systems are expected to extend service areas from the office to the so-called “hot-spot" in public areas. Underground shopping malls are one of the anticipated service areas for such a nomadic wireless access service. Broadband propagation characteristics are required for radio zone design in an underground mall environment despite previous results obtained by narrow band measurements. This paper presents results of an experimental study on the propagation characteristics for broadband wireless access systems in an underground mall environment. First, broadband propagation path loss is measured and formulated considering human body shadowing. A ray trace simulation is used to clarify the basic propagation mechanism in such a closed environment. Next, a distance dependency of the delay spread during a crowded time period, rush hour, is found to be at most 65 nsec, which is under the permitted maximum value of the present 5-GHz systems. Finally, above propagation characteristics support the result of transmission test carried out by using AWA equipment.

  2. Performance Evaluation of an Autonomous Adaptive Base Station that Supports Multiple Wireless Network Systems

    NASA Astrophysics Data System (ADS)

    Akabane, Kazunori; Shiba, Hiroyuki; Matsui, Munehiro; Uehara, Kazuhiro

    Various wireless systems are being developed to meet users' needs, and the rapid increase in frequency demand that accompanies the increasing popularity of wireless services means that more effective use of frequency resources is urgently needed. However, existing base stations are making no effort to use frequency resources effectively, and cooperation among wireless system base stations is needed to use frequency resources more effectively. Base stations can cooperate more efficiently if they are able to use multiple channels of many wireless systems simultaneously. We propose an autonomous adaptive base station (AABS) that can switch among various wireless systems the way software defined radio (SDR) base stations do. AABS can autonomously select and use the most suitable wireless system on the basis of user traffic and its hardware resources. Moreover, frequency resources are used effectively because AABS prevents unnecessary radio wave transmission when the number of users in the wireless systems decreases. AABS is also suitable for “multi-link communication” because it can use multiple channels of multiple wireless systems simultaneously. We developed AABS prototype and evaluated its performance. Our experimental and computer simulation results show the performance of AABS and its efficiency.

  3. Printed Notched Antenna with Long Meandered Line for Eight-Band LTE/GSM/UMTS Wireless USB Dongle Operation

    NASA Astrophysics Data System (ADS)

    Zhang, Y. H.; Sun, S. C.; Ban, Y. L.; Tang, X. H.

    2016-03-01

    This paper presents a planar notched antenna with a long meandered line for wireless USB dongle applications. The printed notched structure is used as additional resonators to generate multiple bands operation for covering GSM1800/1900/UMTS2100/LTE2300/2500 bands. In addition, with the help of the long meandered line via hole to ground, a lower resonant mode is sufficiently generated at around 770 MHz and forms a wider lower operating bandwidth (LTE700/GSM850/900). Briefly printed on a 0.8 mm thick FR4 dielectric substrate of size 20×70 mm² and electrically connected (via hole) to the ground plane of the USB dongle, the proposed antenna can provide a wide operating bandwidth (3:1 VSWR) of larger than 120 % centered at 2,000 MHz, allowing it to cover 698-960 and 1,710-2,690 MHz bands. The proposed antenna also can be attached to laptop computer by the USB interface. Detailed design considerations of the proposed antenna are described, and obtained experimental and simulation results are also presented and discussed in this paper.

  4. 47 CFR 27.1250 - Transition of the 2150-2160/62 MHz band from the Broadband Radio Service to the Advanced Wireless...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... the Broadband Radio Service to the Advanced Wireless Service. 27.1250 Section 27.1250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS... Service to the Advanced Wireless Service. The 2150-2160/62 MHz band has been allocated for use by...

  5. 47 CFR 27.1250 - Transition of the 2150-2160/62 MHz band from the Broadband Radio Service to the Advanced Wireless...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the Broadband Radio Service to the Advanced Wireless Service. 27.1250 Section 27.1250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS... Service to the Advanced Wireless Service. The 2150-2160/62 MHz band has been allocated for use by...

  6. 47 CFR 27.1250 - Transition of the 2150-2160/62 MHz band from the Broadband Radio Service to the Advanced Wireless...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the Broadband Radio Service to the Advanced Wireless Service. 27.1250 Section 27.1250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS... Service to the Advanced Wireless Service. The 2150-2160/62 MHz band has been allocated for use by...

  7. 47 CFR 27.1250 - Transition of the 2150-2160/62 MHz band from the Broadband Radio Service to the Advanced Wireless...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... the Broadband Radio Service to the Advanced Wireless Service. 27.1250 Section 27.1250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS... Service to the Advanced Wireless Service. The 2150-2160/62 MHz band has been allocated for use by...

  8. 47 CFR 27.1250 - Transition of the 2150-2160/62 MHz band from the Broadband Radio Service to the Advanced Wireless...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... the Broadband Radio Service to the Advanced Wireless Service. 27.1250 Section 27.1250 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS... Service to the Advanced Wireless Service. The 2150-2160/62 MHz band has been allocated for use by...

  9. Diluted II-VI oxide semiconductors with multiple band gaps.

    PubMed

    Yu, K M; Walukiewicz, W; Wu, J; Shan, W; Beeman, J W; Scarpulla, M A; Dubon, O D; Becla, P

    2003-12-12

    We report the realization of a new mult-band-gap semiconductor. Zn(1-y)Mn(y)OxTe1-x alloys have been synthesized using the combination of oxygen ion implantation and pulsed laser melting. Incorporation of small quantities of isovalent oxygen leads to the formation of a narrow, oxygen-derived band of extended states located within the band gap of the Zn(1-y)Mn(y)Te host. When only 1.3% of Te atoms are replaced with oxygen in a Zn0.88Mn0.12Te crystal the resulting band structure consists of two direct band gaps with interband transitions at approximately 1.77 and 2.7 eV. This remarkable modification of the band structure is well described by the band anticrossing model. With multiple band gaps that fall within the solar energy spectrum, Zn(1-y)Mn(y)OxTe1-x is a material perfectly satisfying the conditions for single-junction photovoltaics with the potential for power conversion efficiencies surpassing 50%.

  10. Wireless sensor networks for monitoring physiological signals of multiple patients.

    PubMed

    Dilmaghani, R S; Bobarshad, H; Ghavami, M; Choobkar, S; Wolfe, C

    2011-08-01

    This paper presents the design of a novel wireless sensor network structure to monitor patients with chronic diseases in their own homes through a remote monitoring system of physiological signals. Currently, most of the monitoring systems send patients' data to a hospital with the aid of personal computers (PC) located in the patients' home. Here, we present a new design which eliminates the need for a PC. The proposed remote monitoring system is a wireless sensor network with the nodes of the network installed in the patients' homes. These nodes are then connected to a central node located at a hospital through an Internet connection. The nodes of the proposed wireless sensor network are created by using a combination of ECG sensors, MSP430 microcontrollers, a CC2500 low-power wireless radio, and a network protocol called the SimpliciTI protocol. ECG signals are first sampled by a small portable device which each patient carries. The captured signals are then wirelessly transmitted to an access point located within the patients' home. This connectivity is based on wireless data transmission at 2.4-GHz frequency. The access point is also a small box attached to the Internet through a home asynchronous digital subscriber line router. Afterwards, the data are sent to the hospital via the Internet in real time for analysis and/or storage. The benefits of this remote monitoring are wide ranging: the patients can continue their normal lives, they do not need a PC all of the time, their risk of infection is reduced, costs significantly decrease for the hospital, and clinicians can check data in a short time. PMID:23851949

  11. Wireless sensor networks for monitoring physiological signals of multiple patients.

    PubMed

    Dilmaghani, R S; Bobarshad, H; Ghavami, M; Choobkar, S; Wolfe, C

    2011-08-01

    This paper presents the design of a novel wireless sensor network structure to monitor patients with chronic diseases in their own homes through a remote monitoring system of physiological signals. Currently, most of the monitoring systems send patients' data to a hospital with the aid of personal computers (PC) located in the patients' home. Here, we present a new design which eliminates the need for a PC. The proposed remote monitoring system is a wireless sensor network with the nodes of the network installed in the patients' homes. These nodes are then connected to a central node located at a hospital through an Internet connection. The nodes of the proposed wireless sensor network are created by using a combination of ECG sensors, MSP430 microcontrollers, a CC2500 low-power wireless radio, and a network protocol called the SimpliciTI protocol. ECG signals are first sampled by a small portable device which each patient carries. The captured signals are then wirelessly transmitted to an access point located within the patients' home. This connectivity is based on wireless data transmission at 2.4-GHz frequency. The access point is also a small box attached to the Internet through a home asynchronous digital subscriber line router. Afterwards, the data are sent to the hospital via the Internet in real time for analysis and/or storage. The benefits of this remote monitoring are wide ranging: the patients can continue their normal lives, they do not need a PC all of the time, their risk of infection is reduced, costs significantly decrease for the hospital, and clinicians can check data in a short time.

  12. Design of a Ku band miniature multiple beam klystron

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, Ayan Kumar; Pal, Debasish; Saini, Anil; Kant, Deepender; Saha, Sukalyan; Joshi, Lalit Mohan

    2016-03-01

    The design of a miniature multiple beam klystron (MBK) working in the Ku-band frequency range is presented in this article. Starting from the main design parameters, design of the electron gun, the input and output couplers and radio frequency section (RF-section) are presented. The design methodology using state of the art commercial electromagnetic design tools, analytical formulae as well as noncommercial design tools are briefly presented in this article.

  13. Entrained neural oscillations in multiple frequency bands comodulate behavior

    PubMed Central

    Henry, Molly J.; Herrmann, Björn

    2014-01-01

    Our sensory environment is teeming with complex rhythmic structure, to which neural oscillations can become synchronized. Neural synchronization to environmental rhythms (entrainment) is hypothesized to shape human perception, as rhythmic structure acts to temporally organize cortical excitability. In the current human electroencephalography study, we investigated how behavior is influenced by neural oscillatory dynamics when the rhythmic fluctuations in the sensory environment take on a naturalistic degree of complexity. Listeners detected near-threshold gaps in auditory stimuli that were simultaneously modulated in frequency (frequency modulation, 3.1 Hz) and amplitude (amplitude modulation, 5.075 Hz); modulation rates and types were chosen to mimic the complex rhythmic structure of natural speech. Neural oscillations were entrained by both the frequency modulation and amplitude modulation in the stimulation. Critically, listeners’ target-detection accuracy depended on the specific phase–phase relationship between entrained neural oscillations in both the 3.1-Hz and 5.075-Hz frequency bands, with the best performance occurring when the respective troughs in both neural oscillations coincided. Neural-phase effects were specific to the frequency bands entrained by the rhythmic stimulation. Moreover, the degree of behavioral comodulation by neural phase in both frequency bands exceeded the degree of behavioral modulation by either frequency band alone. Our results elucidate how fluctuating excitability, within and across multiple entrained frequency bands, shapes the effective neural processing of environmental stimuli. More generally, the frequency-specific nature of behavioral comodulation effects suggests that environmental rhythms act to reduce the complexity of high-dimensional neural states. PMID:25267634

  14. Low power wireless ultra-wide band transmission of bio-signals

    NASA Astrophysics Data System (ADS)

    Gabrielli, A.; Bastianini, S.; Crepaldi, M.; D'Amen, G.; Demarchi, D.; Lax, I.; Motto Ros, P.; Zoccoli, G.

    2014-12-01

    The paper shows the design of microelectronic circuits composed of an oscillator, a modulator, a transmitter and an antenna. Prototype chips were recently fabricated and tested exploiting commercial 130 nm [1] and 180 nm [2,3] CMOS technologies. Detected signals have been measured using a commercial Ultra-Wide-Band amplifier connected to custom designed filters and a digital demodulator. Preliminary results are summarized along with some waveforms of the transmitted and received signals. A digital Synchronized On-Off Keying (S-OOK) was implemented to exploit the Ultra-Wide-Band transmission. In this way, each transmitted bit is coded with a S-OOK protocol. Wireless transmission capabilities of the system have been also evaluated within a one-meter distance. The chips fit a large variety of applications like spot radiation monitoring, punctual measurements of radiation in High-Energy Physics experiments or, since they have been characterized as low-power components, readout of the system for medical applications. These latter fields are those that we are investigating for in-vivo measurements on small animals. In more detail, if we refer to electromyographic, electrocardiographic or electroencephalographic signals [4], we need to handle very small signal amplitudes, of the order of tens of μV, overwhelmed with a much higher (white) noise. In these cases the front-end of the readout circuit requires a so-called amplifier for instrumentation, here not described, to interface with metal-plate sensor's outputs such those used for electrocardiograms, to normal range of amplitude signals of the order of 1 V. We are also studying these circuits, to be also designed on a microelectronic device, without adding further details since these components are technically well known in the literature [5,6]. The main aim of this research is hence integrating all the described electronic components into a very small, low-powered, microelectronic circuit fully compatible with in

  15. Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands.

    PubMed

    Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

    2016-06-21

    The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich's flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs. PMID:27224201

  16. Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands

    NASA Astrophysics Data System (ADS)

    Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

    2016-06-01

    The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich’s flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

  17. A Multiple-Channel Sub-Band Transient Detection System

    SciTech Connect

    David A. Smith

    1998-11-01

    We have developed a unique multiple-channel sub-band transient detection system to record transient electromagnetic signals in carrier-dominated radio environments; the system has been used to make unique observations of weak, transient HF signals. The detection system has made these observations possible through improved sensitivity compared to conventional broadband transient detection systems; the sensitivity improvement is estimated to be at least 20 dB. The increase in sensitivity has been achieved through subdivision of the band of interest (an 18 MHz tunable bandwidth) into eight sub-band independent detection channels, each with a 400 kHz bandwidth and its own criteria. The system generates a system trigger signal when a predetermined number of channels (typically five) trigger within a predetermined window of time (typically 100 ~s). Events are recorded with a broadband data acquisition system sampling at 50 or 100 Msample/s, so despite the fact that the detection system operates on portions of the signal confined to narrow bands, data acquisition is broadband. Between May and September of 1994, the system was used to detect and record over six thousand transient events in the frequency band from 3 to 30 MHz. Approximately 500 of the events have been characterized as paired bursts of radio noise with individual durations of 2 to 10 ps and separations between the bursts of 5 to 160 ps. The paired transients are typically 5 to 40 dB brighter than the background electromagnetic spectrum between carrier signals. We have termed these events SubIonospheric Pulse Pairs (SIPPS) and presently have no explanation as to their source. Our observations of SIPPS resemble observations of TransIonospheric Pulse Pairs (TIPPs) recorded by the Blackboard instrument on the ALEXIS satellite; the source of TIPP events is also unknown. Most of the recorded SIPP events do not exhibit frequency dispersion, implying propagation along a line-of-sight (groundwave) path; but seven of

  18. Ultrahigh-capacity access network architecture for mobile data backhaul using integrated W-band wireless and free-space optical links with OAM multiplexing.

    PubMed

    Fang, Yuan; Yu, Jianjun; Zhang, Junwen; Chi, Nan; Xiao, Jiangnan; Chang, Gee-Kung

    2014-07-15

    In this Letter, we propose and experimentally demonstrate a novel access network architecture using hybrid integrated W-band wireless and free-space optical (FSO) links with orbital angular momentum (OAM) multiplexing. The transmission of a 20 GBd quadrature phase-shift keying signal modulated over 10 OAM modes has been demonstrated over a 0.6 m FSO link and a 0.4 m W-band wireless link at 100 GHz. The experimental results show that the architecture can support future ultrahigh-capacity, converged optical-wireless access networks that require extra bandwidth and system flexibility in mobile data networks.

  19. Towards Mitigating Heterogeneous Wireless Interference in Spectrum Bands with Unlicensed Access

    ERIC Educational Resources Information Center

    Nychis, George P.

    2013-01-01

    In the past two decades, we have seen an unprecedented rise in unlicensed wireless devices and applications of wireless technology. To meet various application constraints, we continually customize the radios and their protocols to the application domain which has led to significant diversity in spectrum use. Unfortunately, this diversity (coupled…

  20. Adaptive Multi-Node Multiple Input and Multiple Output (MIMO) Transmission for Mobile Wireless Multimedia Sensor Networks

    PubMed Central

    Cho, Sunghyun; Choi, Ji-Woong; You, Cheolwoo

    2013-01-01

    Mobile wireless multimedia sensor networks (WMSNs), which consist of mobile sink or sensor nodes and use rich sensing information, require much faster and more reliable wireless links than static wireless sensor networks (WSNs). This paper proposes an adaptive multi-node (MN) multiple input and multiple output (MIMO) transmission to improve the transmission reliability and capacity of mobile sink nodes when they experience spatial correlation. Unlike conventional single-node (SN) MIMO transmission, the proposed scheme considers the use of transmission antennas from more than two sensor nodes. To find an optimal antenna set and a MIMO transmission scheme, a MN MIMO channel model is introduced first, followed by derivation of closed-form ergodic capacity expressions with different MIMO transmission schemes, such as space-time transmit diversity coding and spatial multiplexing. The capacity varies according to the antenna correlation and the path gain from multiple sensor nodes. Based on these statistical results, we propose an adaptive MIMO mode and antenna set switching algorithm that maximizes the ergodic capacity of mobile sink nodes. The ergodic capacity of the proposed scheme is compared with conventional SN MIMO schemes, where the gain increases as the antenna correlation and path gain ratio increase. PMID:24152920

  1. Adaptive multi-node multiple input and multiple output (MIMO) transmission for mobile wireless multimedia sensor networks.

    PubMed

    Cho, Sunghyun; Choi, Ji-Woong; You, Cheolwoo

    2013-10-02

    Mobile wireless multimedia sensor networks (WMSNs), which consist of mobile sink or sensor nodes and use rich sensing information, require much faster and more reliable wireless links than static wireless sensor networks (WSNs). This paper proposes an adaptive multi-node (MN) multiple input and multiple output (MIMO) transmission to improve the transmission reliability and capacity of mobile sink nodes when they experience spatial correlation. Unlike conventional single-node (SN) MIMO transmission, the proposed scheme considers the use of transmission antennas from more than two sensor nodes. To find an optimal antenna set and a MIMO transmission scheme, a MN MIMO channel model is introduced first, followed by derivation of closed-form ergodic capacity expressions with different MIMO transmission schemes, such as space-time transmit diversity coding and spatial multiplexing. The capacity varies according to the antenna correlation and the path gain from multiple sensor nodes. Based on these statistical results, we propose an adaptive MIMO mode and antenna set switching algorithm that maximizes the ergodic capacity of mobile sink nodes. The ergodic capacity of the proposed scheme is compared with conventional SN MIMO schemes, where the gain increases as the antenna correlation and path gain ratio increase.

  2. The optimization based dynamic and cyclic working strategies for rechargeable wireless sensor networks with multiple base stations and wireless energy transfer devices.

    PubMed

    Ding, Xu; Han, Jianghong; Shi, Lei

    2015-03-16

    In this paper, the optimal working schemes for wireless sensor networks with multiple base stations and wireless energy transfer devices are proposed. The wireless energy transfer devices also work as data gatherers while charging sensor nodes. The wireless sensor network is firstly divided into sub networks according to the concept of Voronoi diagram. Then, the entire energy replenishing procedure is split into the pre-normal and normal energy replenishing stages. With the objective of maximizing the sojourn time ratio of the wireless energy transfer device, a continuous time optimization problem for the normal energy replenishing cycle is formed according to constraints with which sensor nodes and wireless energy transfer devices should comply. Later on, the continuous time optimization problem is reshaped into a discrete multi-phased optimization problem, which yields the identical optimality. After linearizing it, we obtain a linear programming problem that can be solved efficiently. The working strategies of both sensor nodes and wireless energy transfer devices in the pre-normal replenishing stage are also discussed in this paper. The intensive simulations exhibit the dynamic and cyclic working schemes for the entire energy replenishing procedure. Additionally, a way of eliminating "bottleneck" sensor nodes is also developed in this paper.

  3. The Optimization Based Dynamic and Cyclic Working Strategies for Rechargeable Wireless Sensor Networks with Multiple Base Stations and Wireless Energy Transfer Devices

    PubMed Central

    Ding, Xu; Han, Jianghong; Shi, Lei

    2015-01-01

    In this paper, the optimal working schemes for wireless sensor networks with multiple base stations and wireless energy transfer devices are proposed. The wireless energy transfer devices also work as data gatherers while charging sensor nodes. The wireless sensor network is firstly divided into sub networks according to the concept of Voronoi diagram. Then, the entire energy replenishing procedure is split into the pre-normal and normal energy replenishing stages. With the objective of maximizing the sojourn time ratio of the wireless energy transfer device, a continuous time optimization problem for the normal energy replenishing cycle is formed according to constraints with which sensor nodes and wireless energy transfer devices should comply. Later on, the continuous time optimization problem is reshaped into a discrete multi-phased optimization problem, which yields the identical optimality. After linearizing it, we obtain a linear programming problem that can be solved efficiently. The working strategies of both sensor nodes and wireless energy transfer devices in the pre-normal replenishing stage are also discussed in this paper. The intensive simulations exhibit the dynamic and cyclic working schemes for the entire energy replenishing procedure. Additionally, a way of eliminating “bottleneck” sensor nodes is also developed in this paper. PMID:25785305

  4. Hybrid wireless-over-fiber transmission system based on multiple injection-locked FP LDs.

    PubMed

    Li, Chung-Yi; Lu, Hai-Han; Chu, Chien-An; Ying, Cheng-Ling; Lu, Ting-Chien; Peng, Peng-Chun

    2015-07-27

    A hybrid wireless-over-fiber (WoF) transmission system based on multiple injection-locked Fabry-Perot laser diodes (FP LDs) is proposed and experimentally demonstrated. Unlike the traditional hybrid WoF transmission systems that require multiple distributed feedback (DFB) LDs to support different kinds of services, the proposed system employs multiple injection-locked FP LDs to provide different kinds of applications. Such a hybrid WoF transmission system delivers downstream intensity-modulated 20-GHz microwave (MW)/60-GHz millimeter-wave (MMW)/550-MHz cable television (CATV) signals and upstream phase-remodulated 20-GHz MW signal. Excellent bit error rate (BER), carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple-beat (CTB) are observed over a 40-km single-mode fiber (SMF) and a 4-m radio frequency (RF) wireless transport. Such a hybrid WoF transmission system has practical applications for fiber-wireless convergence to provide broadband integrated services, including telecommunication, data communication, and CATV services.

  5. Hybrid wireless-over-fiber transmission system based on multiple injection-locked FP LDs.

    PubMed

    Li, Chung-Yi; Lu, Hai-Han; Chu, Chien-An; Ying, Cheng-Ling; Lu, Ting-Chien; Peng, Peng-Chun

    2015-07-27

    A hybrid wireless-over-fiber (WoF) transmission system based on multiple injection-locked Fabry-Perot laser diodes (FP LDs) is proposed and experimentally demonstrated. Unlike the traditional hybrid WoF transmission systems that require multiple distributed feedback (DFB) LDs to support different kinds of services, the proposed system employs multiple injection-locked FP LDs to provide different kinds of applications. Such a hybrid WoF transmission system delivers downstream intensity-modulated 20-GHz microwave (MW)/60-GHz millimeter-wave (MMW)/550-MHz cable television (CATV) signals and upstream phase-remodulated 20-GHz MW signal. Excellent bit error rate (BER), carrier-to-noise ratio (CNR), composite second-order (CSO), and composite triple-beat (CTB) are observed over a 40-km single-mode fiber (SMF) and a 4-m radio frequency (RF) wireless transport. Such a hybrid WoF transmission system has practical applications for fiber-wireless convergence to provide broadband integrated services, including telecommunication, data communication, and CATV services. PMID:26367647

  6. Detection of Biological Pathogens Using Multiple Wireless Magnetoelastic Biosensors

    NASA Astrophysics Data System (ADS)

    Shen, Wen

    A number of recent, high-profile incidences of food-borne illness spreading through the food supply and the use of anthrax by terrorists after the September 11, 2001 attacks have demonstrated the need for new technologies that can rapidly detect the presence of biological pathogens. A bevy of biosensors show excellent detection sensitivity and specificity. However, false positive and false negative signals remain one of the primary reasons that many of these newly developed biosensors have not found application in the marketplace. The research described in this dissertation focuses on developing a free-standing magnetoelastic based bio-sensing system using a pulse method. This method allows fast detection, eliminates the bias magnetic field that is necessary in current methods, makes the system more simply and suitable for in-field detection. This system has two pairs of transformer coils, where a measurement sensor and a control sensor can be put in each pair of coils. The control sensor is used to compensate for environmental variables. The effect of pulse power on the performance of the magnetoelastic sensors in the pulse system is studied. The system is found to have excellent stability, good detection repeatability when used with multiple sensors. This research has investigated and demonstrated a multiple sensors approach. Because it will involve the simultaneous measurement of many sensors, it will significantly reduce problems encountered with false positive indications. The positioning and interference of sensors are investigated. By adding a multi-channel structure to the pulse detection system, the effect of sensor interference is minimized. The result of the repeatability test shows that the standard deviation when measuring three 1 mm magnetoelastic sensors is around 500 Hz, which is smaller than the minimum requirement for actual spores/bacteria detection. Magnetoelastic sensors immobilized with JRB7 phages and E2 phages have been used to specifically

  7. Fractal nature of multiple shear bands in severely deformed metallic glass

    SciTech Connect

    Sun, B. A.; Wang, W. H.

    2011-05-16

    We present an analysis of fractal geometry of extensive and complex shear band patterns in a severely deformed metallic glass. We show that the shear band patterns have fractal characteristics, and the fractal dimensions are determined by the stress noise induced by the interaction between shear bands. A theoretical model of the spatial evolution of multiple shear bands is proposed in which the collective shear bands slide is considered as a stochastic process far from thermodynamic equilibrium.

  8. High spectral efficient W-band optical/wireless system employing single-sideband single-carrier modulation.

    PubMed

    Ho, Chun-Hung; Lin, Chun-Ting; Cheng, Yu-Hsuan; Huang, Hou-Tzu; Wei, Chia-Chien; Chi, Sien

    2014-02-24

    With broader available bandwidth, W-band wireless transmission has attracted a lot of interests for future Giga-bit communication. In this article, we experimentally demonstrate W-band radio-over-fiber (RoF) system employing single-sideband single-carrier (SSB-SC) modulation with lower peak-to-average-power ratio (PAPR) than orthogonal frequency division multiplex (OFDM). To overcome the inter-symbol interference (ISI) of the penalty from uneven frequency response and SSB-SC modulation, frequency domain equalizer (FDE) and decision feedback equalizer (DFE) are implemented. We discuss the maximum available bandwidth of different modulation formats between SSB-SC and OFDM signals at the BER below forward error correction (FEC) threshold (3.8 × 10(-3)). Up to 50-Gbps 32-QAM SSB-SC signals with spectral efficiency of 5 bit/s/Hz can be achieved. PMID:24663711

  9. Massive MIMO for Wireless Sensing With a Coherent Multiple Access Channel

    NASA Astrophysics Data System (ADS)

    Jiang, Feng; Chen, Jie; Swindlehurst, A. Lee; Lopez-Salcedo, Jose A.

    2015-06-01

    We consider the detection and estimation of a zero-mean Gaussian signal in a wireless sensor network with a coherent multiple access channel, when the fusion center (FC) is configured with a large number of antennas and the wireless channels between the sensor nodes and FC experience Rayleigh fading. For the detection problem, we study the Neyman-Pearson (NP) Detector and Energy Detector (ED), and find optimal values for the sensor transmission gains. For the NP detector which requires channel state information (CSI), we show that detection performance remains asymptotically constant with the number of FC antennas if the sensor transmit power decreases proportionally with the increase in the number of antennas. Performance bounds show that the benefit of multiple antennas at the FC disappears as the transmit power grows. The results of the NP detector are also generalized to the linear minimum mean squared error estimator. For the ED which does not require CSI, we derive optimal gains that maximize the deflection coefficient of the detector, and we show that a constant deflection can be asymptotically achieved if the sensor transmit power scales as the inverse square root of the number of FC antennas. Unlike the NP detector, for high sensor power the multi-antenna ED is observed to empirically have significantly better performance than the single-antenna implementation. A number of simulation results are included to validate the analysis.

  10. Full-duplex bidirectional transmission of 10-Gb/s millimeter-wave QPSK signal in E-band optical wireless link.

    PubMed

    Fang, Yuan; Yu, Jianjun; Chi, Nan; Xiao, Jiangnan

    2014-01-27

    We experimentally demonstrated full-duplex bidirectional transmission of 10-Gb/s millimeter-wave (mm-wave) quadrature phase shift keying (QPSK) signal in E-band (71-76 GHz and 81-86 GHz) optical wireless link. Single-mode fibers (SMF) are connected at both sides of the antenna for uplink and downlink which realize 40-km SMF and 2-m wireless link for bidirectional transmission simultaneously. We utilized multi-level modulation format and coherent detection in such E-band optical wireless link for the first time. Mm-wave QPSK signal is generated by photonic technique to increase spectrum efficiency and received signal is coherently detected to improve receiver sensitivity. After the coherent detection, digital signal processing is utilized to compensate impairments of devices and transmission link.

  11. Multi-band asymmetric acoustic transmission in a bended waveguide with multiple mechanisms

    NASA Astrophysics Data System (ADS)

    Huang, Yu-lei; Sun, Hong-xiang; Xia, Jian-ping; Yuan, Shou-qi; Ding, Xin-lei

    2016-07-01

    We report the realization of a multi-band device of the asymmetric acoustic transmission by placing a phononic crystal inside a bended waveguide immersed in water, as determined both experimentally and numerically. The asymmetric acoustic transmission exists in three frequency bands below 500 kHz induced by multiple mechanisms. Besides the band gap of the phononic crystal, we also introduce the deaf mode and interaction between the phononic crystal and waveguide. More importantly, this asymmetric transmission can be systematically controlled by mechanically rotating the square rods of the phononic crystal. The device has the advantages of multiple band, broader bandwidth, and adjustable property, showing promising applications in ultrasonic devices.

  12. Wireless Channel Characterization: Modeling the 5 GHz Microwave Landing System Extension Band for Future Airport Surface Communications

    NASA Technical Reports Server (NTRS)

    Matolak, D. W.; Apaza, Rafael; Foore, Lawrence R.

    2006-01-01

    We describe a recently completed wideband wireless channel characterization project for the 5 GHz Microwave Landing System (MLS) extension band, for airport surface areas. This work included mobile measurements at large and small airports, and fixed point-to-point measurements. Mobile measurements were made via transmission from the air traffic control tower (ATCT), or from an airport field site (AFS), to a receiving ground vehicle on the airport surface. The point-to-point measurements were between ATCT and AFSs. Detailed statistical channel models were developed from all these measurements. Measured quantities include propagation path loss and power delay profiles, from which we obtain delay spreads, frequency domain correlation (coherence bandwidths), fading amplitude statistics, and channel parameter correlations. In this paper we review the project motivation, measurement coordination, and illustrate measurement results. Example channel modeling results for several propagation conditions are also provided, highlighting new findings.

  13. Personalization algorithm for real-time activity recognition using PDA, wireless motion bands, and binary decision tree.

    PubMed

    Pärkkä, Juha; Cluitmans, Luc; Ermes, Miikka

    2010-09-01

    Inactive and sedentary lifestyle is a major problem in many industrialized countries today. Automatic recognition of type of physical activity can be used to show the user the distribution of his daily activities and to motivate him into more active lifestyle. In this study, an automatic activity-recognition system consisting of wireless motion bands and a PDA is evaluated. The system classifies raw sensor data into activity types online. It uses a decision tree classifier, which has low computational cost and low battery consumption. The classifier parameters can be personalized online by performing a short bout of an activity and by telling the system which activity is being performed. Data were collected with seven volunteers during five everyday activities: lying, sitting/standing, walking, running, and cycling. The online system can detect these activities with overall 86.6% accuracy and with 94.0% accuracy after classifier personalization.

  14. Multimodal wireless sensor network-based ambient assisted living in real homes with multiple residents.

    PubMed

    Tunca, Can; Alemdar, Hande; Ertan, Halil; Incel, Ozlem Durmaz; Ersoy, Cem

    2014-01-01

    Human activity recognition and behavior monitoring in a home setting using wireless sensor networks (WSNs) provide a great potential for ambient assisted living (AAL) applications, ranging from health and wellbeing monitoring to resource consumption monitoring. However, due to the limitations of the sensor devices, challenges in wireless communication and the challenges in processing large amounts of sensor data in order to recognize complex human activities, WSN-based AAL systems are not effectively integrated in the home environment. Additionally, given the variety of sensor types and activities, selecting the most suitable set of sensors in the deployment is an important task. In order to investigate and propose solutions to such challenges, we introduce a WSN-based multimodal AAL system compatible for homes with multiple residents. Particularly, we focus on the details of the system architecture, including the challenges of sensor selection, deployment, networking and data collection and provide guidelines for the design and deployment of an effective AAL system. We also present the details of the field study we conducted, using the systems deployed in two different real home environments with multiple residents. With these systems, we are able to collect ambient sensor data from multiple homes. This data can be used to assess the wellbeing of the residents and identify deviations from everyday routines, which may be indicators of health problems. Finally, in order to elaborate on the possible applications of the proposed AAL system and to exemplify directions for processing the collected data, we provide the results of several human activity inference experiments, along with examples on how such results could be interpreted. We believe that the experiences shared in this work will contribute towards accelerating the acceptance of WSN-based AAL systems in the home setting. PMID:24887044

  15. Multimodal Wireless Sensor Network-Based Ambient Assisted Living in Real Homes with Multiple Residents

    PubMed Central

    Tunca, Can; Alemdar, Hande; Ertan, Halil; Incel, Ozlem Durmaz; Ersoy, Cem

    2014-01-01

    Human activity recognition and behavior monitoring in a home setting using wireless sensor networks (WSNs) provide a great potential for ambient assisted living (AAL) applications, ranging from health and wellbeing monitoring to resource consumption monitoring. However, due to the limitations of the sensor devices, challenges in wireless communication and the challenges in processing large amounts of sensor data in order to recognize complex human activities, WSN-based AAL systems are not effectively integrated in the home environment. Additionally, given the variety of sensor types and activities, selecting the most suitable set of sensors in the deployment is an important task. In order to investigate and propose solutions to such challenges, we introduce a WSN-based multimodal AAL system compatible for homes with multiple residents. Particularly, we focus on the details of the system architecture, including the challenges of sensor selection, deployment, networking and data collection and provide guidelines for the design and deployment of an effective AAL system. We also present the details of the field study we conducted, using the systems deployed in two different real home environments with multiple residents. With these systems, we are able to collect ambient sensor data from multiple homes. This data can be used to assess the wellbeing of the residents and identify deviations from everyday routines, which may be indicators of health problems. Finally, in order to elaborate on the possible applications of the proposed AAL system and to exemplify directions for processing the collected data, we provide the results of several human activity inference experiments, along with examples on how such results could be interpreted. We believe that the experiences shared in this work will contribute towards accelerating the acceptance of WSN-based AAL systems in the home setting. PMID:24887044

  16. 40 Gb/s W-band (75-110 GHz) 16-QAM radio-over-fiber signal generation and its wireless transmission.

    PubMed

    Kanno, Atsushi; Inagaki, Keizo; Morohashi, Isao; Sakamoto, Takahide; Kuri, Toshiaki; Hosako, Iwao; Kawanishi, Tetsuya; Yoshida, Yuki; Kitayama, Ken-ichi

    2011-12-12

    The generation of a 40-Gb/s 16-QAM radio-over-fiber (RoF) signal and its demodulation of the wireless signal transmitted over free space of 30 mm in W-band (75-110 GHz) is demonstrated. The 16-QAM signal is generated by a coherent polarization synthesis method using a dual-polarization QPSK modulator. A combination of the simple RoF generation and the versatile digital receiver technique is suitable for the proposed coherent optical/wireless seamless network.

  17. Tracking and Recognition of Multiple Human Targets Moving in a Wireless Pyroelectric Infrared Sensor Network

    PubMed Central

    Xiong, Ji; Li, Fangmin; Zhao, Ning; Jiang, Na

    2014-01-01

    With characteristics of low-cost and easy deployment, the distributed wireless pyroelectric infrared sensor network has attracted extensive interest, which aims to make it an alternate infrared video sensor in thermal biometric applications for tracking and identifying human targets. In these applications, effectively processing signals collected from sensors and extracting the features of different human targets has become crucial. This paper proposes the application of empirical mode decomposition and the Hilbert-Huang transform to extract features of moving human targets both in the time domain and the frequency domain. Moreover, the support vector machine is selected as the classifier. The experimental results demonstrate that by using this method the identification rates of multiple moving human targets are around 90%. PMID:24759117

  18. Wireless data transmission through in-band on-channel digital audio broadcasting

    NASA Astrophysics Data System (ADS)

    Vigil, A. J.

    1995-12-01

    USA Digital Radio (USADR) is finalizing the development of new state-of-the-art formats for in-band on-channel (IBOC) delivery of digital audio broadcasting (DAB). USADR's IBOC DAB systems are designed for top-notch digital audio delivery as well as enhanced ancillary data transmission capabilities. USADR's AM and FM IBOC DAB systems employ MUSICAMR source encoding as well as innovative modulation techniques which address the various radio channel impairments characteristic of AM and FM band propagation. The USADR IBOC DAB systems are designed to be backwards compatible with conventional AM and FM broadcasting for a seamless and cost-effective transition to DAB.

  19. Practical Performance Analysis for Multiple Information Fusion Based Scalable Localization System Using Wireless Sensor Networks.

    PubMed

    Zhao, Yubin; Li, Xiaofan; Zhang, Sha; Meng, Tianhui; Zhang, Yiwen

    2016-08-23

    In practical localization system design, researchers need to consider several aspects to make the positioning efficiently and effectively, e.g., the available auxiliary information, sensing devices, equipment deployment and the environment. Then, these practical concerns turn out to be the technical problems, e.g., the sequential position state propagation, the target-anchor geometry effect, the Non-line-of-sight (NLOS) identification and the related prior information. It is necessary to construct an efficient framework that can exploit multiple available information and guide the system design. In this paper, we propose a scalable method to analyze system performance based on the Cramér-Rao lower bound (CRLB), which can fuse all of the information adaptively. Firstly, we use an abstract function to represent all of the wireless localization system model. Then, the unknown vector of the CRLB consists of two parts: the first part is the estimated vector, and the second part is the auxiliary vector, which helps improve the estimation accuracy. Accordingly, the Fisher information matrix is divided into two parts: the state matrix and the auxiliary matrix. Unlike the theoretical analysis, our CRLB can be a practical fundamental limit to denote the system that fuses multiple information in the complicated environment, e.g., recursive Bayesian estimation based on the hidden Markov model, the map matching method and the NLOS identification and mitigation methods. Thus, the theoretical results are approaching the real case more. In addition, our method is more adaptable than other CRLBs when considering more unknown important factors. We use the proposed method to analyze the wireless sensor network-based indoor localization system. The influence of the hybrid LOS/NLOS channels, the building layout information and the relative height differences between the target and anchors are analyzed. It is demonstrated that our method exploits all of the available information for

  20. Practical Performance Analysis for Multiple Information Fusion Based Scalable Localization System Using Wireless Sensor Networks.

    PubMed

    Zhao, Yubin; Li, Xiaofan; Zhang, Sha; Meng, Tianhui; Zhang, Yiwen

    2016-01-01

    In practical localization system design, researchers need to consider several aspects to make the positioning efficiently and effectively, e.g., the available auxiliary information, sensing devices, equipment deployment and the environment. Then, these practical concerns turn out to be the technical problems, e.g., the sequential position state propagation, the target-anchor geometry effect, the Non-line-of-sight (NLOS) identification and the related prior information. It is necessary to construct an efficient framework that can exploit multiple available information and guide the system design. In this paper, we propose a scalable method to analyze system performance based on the Cramér-Rao lower bound (CRLB), which can fuse all of the information adaptively. Firstly, we use an abstract function to represent all of the wireless localization system model. Then, the unknown vector of the CRLB consists of two parts: the first part is the estimated vector, and the second part is the auxiliary vector, which helps improve the estimation accuracy. Accordingly, the Fisher information matrix is divided into two parts: the state matrix and the auxiliary matrix. Unlike the theoretical analysis, our CRLB can be a practical fundamental limit to denote the system that fuses multiple information in the complicated environment, e.g., recursive Bayesian estimation based on the hidden Markov model, the map matching method and the NLOS identification and mitigation methods. Thus, the theoretical results are approaching the real case more. In addition, our method is more adaptable than other CRLBs when considering more unknown important factors. We use the proposed method to analyze the wireless sensor network-based indoor localization system. The influence of the hybrid LOS/NLOS channels, the building layout information and the relative height differences between the target and anchors are analyzed. It is demonstrated that our method exploits all of the available information for

  1. Practical Performance Analysis for Multiple Information Fusion Based Scalable Localization System Using Wireless Sensor Networks

    PubMed Central

    Zhao, Yubin; Li, Xiaofan; Zhang, Sha; Meng, Tianhui; Zhang, Yiwen

    2016-01-01

    In practical localization system design, researchers need to consider several aspects to make the positioning efficiently and effectively, e.g., the available auxiliary information, sensing devices, equipment deployment and the environment. Then, these practical concerns turn out to be the technical problems, e.g., the sequential position state propagation, the target-anchor geometry effect, the Non-line-of-sight (NLOS) identification and the related prior information. It is necessary to construct an efficient framework that can exploit multiple available information and guide the system design. In this paper, we propose a scalable method to analyze system performance based on the Cramér–Rao lower bound (CRLB), which can fuse all of the information adaptively. Firstly, we use an abstract function to represent all of the wireless localization system model. Then, the unknown vector of the CRLB consists of two parts: the first part is the estimated vector, and the second part is the auxiliary vector, which helps improve the estimation accuracy. Accordingly, the Fisher information matrix is divided into two parts: the state matrix and the auxiliary matrix. Unlike the theoretical analysis, our CRLB can be a practical fundamental limit to denote the system that fuses multiple information in the complicated environment, e.g., recursive Bayesian estimation based on the hidden Markov model, the map matching method and the NLOS identification and mitigation methods. Thus, the theoretical results are approaching the real case more. In addition, our method is more adaptable than other CRLBs when considering more unknown important factors. We use the proposed method to analyze the wireless sensor network-based indoor localization system. The influence of the hybrid LOS/NLOS channels, the building layout information and the relative height differences between the target and anchors are analyzed. It is demonstrated that our method exploits all of the available information for

  2. Efficient aggregation of multiple classes of information in wireless sensor networks.

    PubMed

    Qiu, Xiaoling; Liu, Haiping; Li, Deshi; Yick, Jennifer; Ghosal, Dipak; Mukherjee, Biswanath

    2009-01-01

    Congestion in a Wireless Sensor Network (WSN) can lead to buffer overflow, resource waste and delay or loss of critical information from the sensors. In this paper, we propose the Priority-based Coverage-aware Congestion Control (PCC) algorithm which is distributed, priority-distinct, and fair. PCC provides higher priority to packets with event information in which the sink is more interested. PCC employs a queue scheduler that can selectively drop any packet in the queue. PCC gives fair chance to all sensors to send packets to the sink, irrespective of their specific locations, and therefore enhances the coverage fidelity of the WSN. Based on a detailed simulation analysis, we show that PCC can efficiently relieve congestion and significantly improve the system performance based on multiple metrics such as event throughput and coverage fidelity. We generalize PCC to address data collection in a WSN in which the sensor nodes have multiple sensing devices and can generate multiple types of information. We propose a Pricing System that can under congestion effectively collect different types of data generated by the sensor nodes according to values that are placed on different information by the sink. Simulation analysis show that our Pricing System can achieve higher event throughput for packets with higher priority and achieve fairness among different categories. Moreover, given a fixed system capacity, our proposed Pricing System can collect more information of the type valued by the sink.

  3. Efficient aggregation of multiple classes of information in wireless sensor networks.

    PubMed

    Qiu, Xiaoling; Liu, Haiping; Li, Deshi; Yick, Jennifer; Ghosal, Dipak; Mukherjee, Biswanath

    2009-01-01

    Congestion in a Wireless Sensor Network (WSN) can lead to buffer overflow, resource waste and delay or loss of critical information from the sensors. In this paper, we propose the Priority-based Coverage-aware Congestion Control (PCC) algorithm which is distributed, priority-distinct, and fair. PCC provides higher priority to packets with event information in which the sink is more interested. PCC employs a queue scheduler that can selectively drop any packet in the queue. PCC gives fair chance to all sensors to send packets to the sink, irrespective of their specific locations, and therefore enhances the coverage fidelity of the WSN. Based on a detailed simulation analysis, we show that PCC can efficiently relieve congestion and significantly improve the system performance based on multiple metrics such as event throughput and coverage fidelity. We generalize PCC to address data collection in a WSN in which the sensor nodes have multiple sensing devices and can generate multiple types of information. We propose a Pricing System that can under congestion effectively collect different types of data generated by the sensor nodes according to values that are placed on different information by the sink. Simulation analysis show that our Pricing System can achieve higher event throughput for packets with higher priority and achieve fairness among different categories. Moreover, given a fixed system capacity, our proposed Pricing System can collect more information of the type valued by the sink. PMID:22408495

  4. Dual band multi frequency rectangular patch microstrip antenna with flyswatter shaped slot for wireless systems

    NASA Astrophysics Data System (ADS)

    Bhardwaj, Dheeraj; Saraswat, Shriti; Gulati, Gitansh; Shekhar, Snehanshu; Joshi, Kanika; Sharma, Komal

    2016-03-01

    In this paper a dual band planar antenna has been proposed for IEEE 802.16 Wi-MAX /IEEE 802.11 WLAN/4.9 GHz public safety applications. The antenna comprises a frequency bandwidth of 560MHz (3.37GHz-3.93GHz) for WLAN and WiMAX and 372MHz (4.82GHz-5.192GHz) for 4.9 GHz public safety applications and Radio astronomy services (4.8-4.94 GHz). The proposed antenna constitutes of a single microstrip patch reactively loaded with three identical steps positioned in a zig-zag manner towards the radiating edges of the patch. The coaxially fed patch antenna characteristics (radiation pattern, antenna gain, antenna directivity, current distribution, S11) have been investigated. The antenna design is primarily focused on achieving a dual band operation.

  5. Circularly polarized triple band glass shaped monopole patch antenna with metallic reflector for bluetooth & wireless applications

    NASA Astrophysics Data System (ADS)

    Jangid, K. G.; Choudhary, N.; Jain, P.; Sharma, B. R.; Saini, J. S.; Kulhar, V. S.; Bhatnagar, D.

    2016-03-01

    This paper presents the design and performance of strip line fed glass shaped monopole patch antenna having with overall size 30mm × 30 mm × 1.59 mm. In the patch; an eight shaped slot and in the ground plane an eight shaped ring are introduced. A metallic ground plane is also introduced at appropriate location beneath the ground plane. The proposed antenna is simulated by applying CST Microwave Studio simulator. Antenna provides circularly polarized radiations, triple broad impedance bandwidth of 203MHz (2.306GHz to 2.510GHz), 42MHz (2.685GHz to 2.757GHz) & GHz (3.63 GHz to 6.05 GHz), high flat gain (close to 5dBi) and good radiation properties in the desired frequency range. This antenna may be a very useful tool for 2.45GHz Bluetooth communication band as well as for 2.4GHz/5.2 GHz /5.8 GHz WLAN bands & 3.7GHz/5.5 GHz Wi-Max bands.

  6. Impact of High Power Interference Sources in Planning and Deployment of Wireless Sensor Networks and Devices in the 2.4 GHz Frequency Band in Heterogeneous Environments

    PubMed Central

    Iturri, Peio López; Nazábal, Juan Antonio; Azpilicueta, Leire; Rodriguez, Pablo; Beruete, Miguel; Fernández-Valdivielso, Carlos; Falcone, Francisco

    2012-01-01

    In this work, the impact of radiofrequency radiation leakage from microwave ovens and its effect on 802.15.4 ZigBee-compliant wireless sensor networks operating in the 2.4 GHz Industrial Scientific Medical (ISM) band is analyzed. By means of a novel radioplanning approach, based on electromagnetic field simulation of a microwave oven and determination of equivalent radiation sources applied to an in-house developed 3D ray launching algorithm, estimation of the microwave oven's power leakage is obtained for the complete volume of an indoor scenario. The magnitude and the variable nature of the interference is analyzed and the impact in the radio link quality in operating wireless sensors is estimated and compared with radio channel measurements as well as packet measurements. The measurement results reveal the importance of selecting an adequate 802.15.4 channel, as well as the Wireless Sensor Network deployment strategy within this type of environment, in order to optimize energy consumption and increase the overall network performance. The proposed method enables one to estimate potential interference effects in devices operating within the 2.4 GHz band in the complete scenario, prior to wireless sensor network deployment, which can aid in achieving the most optimal network topology. PMID:23202228

  7. Numerical investigation of multiple shear bands in collapsing Thick-Walled Cylinders

    NASA Astrophysics Data System (ADS)

    Lovinger, Zev; Rittel, Daniel; Rosenberg, Zvi

    2011-06-01

    The ability to simulate evolution of shear bands in TWC experiments is a powerful tool for studying the complex problem of multiple adiabatic shear bands' formation and propagation. We carry out 2D numerical simulations to reproduce experimental results of multiple shear bands in cylindrical specimens collapsed by electro-magnetic driving forces. In order to simulate the shear bands we use a shear failure model which incorporates a positive feedback mechanism. Alternatively, we use for the Johnson-Cook strength model an enhanced thermal softening term, reaching similar behavior. We present a detailed study of the numerical model, exploring its ability to properly reproduce the evolution of the multiple shear-bands. The influence of initial perturbations, mesh size and pressure history on the initiation and final stages is investigated. Analyzing the shear band distribution, we use an empirical distribution function (ECDF) to reach a quantitative measure to compare simulation and experimental results. Finally, we compare the experimental shear band distribution to our simulations' results, showing good agreement.

  8. Demonstration of Space Optical Transmitter Development for Multiple High Frequency Bands

    NASA Technical Reports Server (NTRS)

    Nguyen, Hung; Simons, Rainee; Wintucky, Edwin; Freeman, Jon

    2013-01-01

    As the demand for multiple radio frequency carrier bands continues to grow in space communication systems, the design of a cost-effective compact optical transmitter that is capable of transmitting selective multiple RF bands is of great interest, particularly for NASA Space Communications Network Programs. This paper presents experimental results that demonstrate the feasibility of a concept based on an optical wavelength division multiplexing (WDM) technique that enables multiple microwave bands with different modulation formats and bandwidths to be combined and transmitted all in one unit, resulting in many benefits to space communication systems including reduced size, weight and complexity with corresponding savings in cost. Experimental results will be presented including the individual received RF signal power spectra for the L, C, X, Ku, Ka, and Q frequency bands, and measurements of the phase noise associated with each RF frequency. Also to be presented is a swept RF frequency power spectrum showing simultaneous multiple RF frequency bands transmission. The RF frequency bands in this experiment are among those most commonly used in NASA space environment communications.

  9. An energy efficient distance-aware routing algorithm with multiple mobile sinks for wireless sensor networks.

    PubMed

    Wang, Jin; Li, Bin; Xia, Feng; Kim, Chang-Seob; Kim, Jeong-Uk

    2014-01-01

    Traffic patterns in wireless sensor networks (WSNs) usually follow a many-to-one model. Sensor nodes close to static sinks will deplete their limited energy more rapidly than other sensors, since they will have more data to forward during multihop transmission. This will cause network partition, isolated nodes and much shortened network lifetime. Thus, how to balance energy consumption for sensor nodes is an important research issue. In recent years, exploiting sink mobility technology in WSNs has attracted much research attention because it can not only improve energy efficiency, but prolong network lifetime. In this paper, we propose an energy efficient distance-aware routing algorithm with multiple mobile sink for WSNs, where sink nodes will move with a certain speed along the network boundary to collect monitored data. We study the influence of multiple mobile sink nodes on energy consumption and network lifetime, and we mainly focus on the selection of mobile sink node number and the selection of parking positions, as well as their impact on performance metrics above. We can see that both mobile sink node number and the selection of parking position have important influence on network performance. Simulation results show that our proposed routing algorithm has better performance than traditional routing ones in terms of energy consumption. PMID:25196015

  10. Design and demonstration of ultra-fast W-band photonic transmitter-mixer and detectors for 25 Gbits/sec error-free wireless linking.

    PubMed

    Chen, Nan-Wei; Shi, Jin-Wei; Tsai, Hsuan-Ju; Wun, Jhih-Min; Kuo, Fong-Ming; Hesler, Jeffery; Crowe, Thomas W; Bowers, John E

    2012-09-10

    A 25 Gbits/s error-free on-off-keying (OOK) wireless link between an ultra high-speed W-band photonic transmitter-mixer (PTM) and a fast W-band envelope detector is demonstrated. At the transmission end, the high-speed PTM is developed with an active near-ballistic uni-traveling carrier photodiode (NBUTC-PD) integrated with broadband front-end circuitry via the flip-chip bonding technique. Compared to our previous work, the wireless data rate is significantly increased through the improvement on the bandwidth of the front-end circuitry together with the reduction of the intermediate-frequency (IF) driving voltage of the active NBUTC-PD. The demonstrated PTM has a record-wide IF modulation (DC-25 GHz) and optical-to-electrical fractional bandwidths (68-128 GHz, ~67%). At the receiver end, the demodulation is realized with an ultra-fast W-band envelope detector built with a zero-bias Schottky barrier diode with a record wide video bandwidth (37 GHz) and excellent sensitivity. The demonstrated PTM is expected to find applications in multi-gigabit short-range wireless communication.

  11. Multiple angle measurement and modeling of M-band x-ray fluxes from vacuum hohlraum

    NASA Astrophysics Data System (ADS)

    Guo, Liang; Li, Shanwei; Li, Zhichao; Jing, Longfei; Xie, Xufei; Jiang, Xiaohua; Yang, Dong; Du, Huabin; Hou, Lifei; Yang, Jiamin; Liu, Shenye; Jiang, Shaoen; Ding, Yongkun; Hu, Guangyue; Zheng, Jian

    2016-09-01

    The energetics experiment of vacuum gold hohlraums is implemented on the Shenguang-II laser facility. The total and M-band x-ray fluxes from the laser entrance holes are measured by the flat response x-ray diodes which are set at multiple angles with respect to the axis of the hohlraums. The measured M-band fractions are from 5.72% to 7.71%, which present a specific angular distribution. Based on the fact that the M-band x-rays are mainly emitted from the under-dense high-temperature plasmas, a simplified model is developed to give a quantitative prediction of the intensity, temporal behavior, and angular distribution of the M-band x-ray flux. The results obtained with our model are in good agreement with the experimental data, showing that our model can be a useful tool for M-band x-ray investigation.

  12. Multiple side-band generation for two-frequency components injected into a tapered amplifier

    NASA Astrophysics Data System (ADS)

    Luo, Hua; Li, Kai; Zhang, Dongfang; Gao, Tianyou; Jiang, Kaijun

    2013-04-01

    We have experimentally studied the multiple side-band generation for two-frequency components injected into a tapered amplifier and demonstrated its effects on atomic laser cooling. A heterodyne frequency-beat measurement and a Fabry Perot interferometer have been applied to analyze the side-band generation with different experimental parameters, such as frequency difference, injection laser power and tapered amplifier current. In laser cooling potassium40 and potassium41 with hyperfine splitting of 1.3GHz and 254MHz, respectively, the side-band generation with a small frequency difference has a significant effect on the number of trapped atoms.

  13. Multiple side-band generation for two-frequency components injected into a tapered amplifier.

    PubMed

    Luo, Hua; Li, Kai; Zhang, Dongfang; Gao, Tianyou; Jiang, Kaijun

    2013-04-01

    We have experimentally studied multiple side-band generation for two-frequency components injected into a tapered amplifier (TA) and demonstrated its effects on atomic laser cooling. A heterodyne frequency-beat measurement and a Fabry-Perot interferometer have been applied to analyze the side-band generation with different experimental parameters, such as frequency difference, injection laser power, and TA current. In laser-cooling potassium40 and potassium41 with hyperfine splitting of 1.3 GHz and 254 MHz, respectively, the side-band generation with a small frequency difference has a significant effect on the number of trapped atoms. PMID:23546277

  14. Wireless communications for a multiple robot system. Master`s thesis

    SciTech Connect

    Bekas, A.J.

    1997-03-01

    A multi-disciplinary research project is being undertaken at NPS to develop a semi-autonomous robotic system to detect and clear land mines and Unexploded Ordnance (UXO). The robotic system under development consists of a land vehicle, an aerial vehicle, and a ground-based control station. Reliable communication between these three stations is needed. A traditional wire-based network requires that the vehicles be tethered and severely limits the mobility of the vehicles. A wireless Local Area Network (LAN) is proposed to provide communications between the control station and the vehicles. The objective of this thesis is to develop the physical (hardware) and logical (software) architecture of a wireless LAN that accommodates the needs of the mine/UXO project. Through an analysis of wireless modulation techniques, a market survey of wireless devices, and a field testing of wireless devices, a wireless LAN is designed to meet the technological, performance, regulation, interference, and mobility requirements of the mine/UXO project. Finally, the wireless communication protocols and the development of an error-free application protocol (specified by a FSM model and implemented in ANSI C code using Windows socket network programming) completes the wireless LAN implementation.

  15. Discrete Particle Swarm Optimization Routing Protocol for Wireless Sensor Networks with Multiple Mobile Sinks

    PubMed Central

    Yang, Jin; Liu, Fagui; Cao, Jianneng; Wang, Liangming

    2016-01-01

    Mobile sinks can achieve load-balancing and energy-consumption balancing across the wireless sensor networks (WSNs). However, the frequent change of the paths between source nodes and the sinks caused by sink mobility introduces significant overhead in terms of energy and packet delays. To enhance network performance of WSNs with mobile sinks (MWSNs), we present an efficient routing strategy, which is formulated as an optimization problem and employs the particle swarm optimization algorithm (PSO) to build the optimal routing paths. However, the conventional PSO is insufficient to solve discrete routing optimization problems. Therefore, a novel greedy discrete particle swarm optimization with memory (GMDPSO) is put forward to address this problem. In the GMDPSO, particle’s position and velocity of traditional PSO are redefined under discrete MWSNs scenario. Particle updating rule is also reconsidered based on the subnetwork topology of MWSNs. Besides, by improving the greedy forwarding routing, a greedy search strategy is designed to drive particles to find a better position quickly. Furthermore, searching history is memorized to accelerate convergence. Simulation results demonstrate that our new protocol significantly improves the robustness and adapts to rapid topological changes with multiple mobile sinks, while efficiently reducing the communication overhead and the energy consumption. PMID:27428971

  16. Multiple Power-Saving MSSs Scheduling Methods for IEEE802.16e Broadband Wireless Networks

    PubMed Central

    2014-01-01

    This work proposes two enhanced multiple mobile subscriber stations (MSSs) power-saving scheduling methods for IEEE802.16e broadband wireless networks. The proposed methods are designed for the Unsolicited Grant Service (UGS) of IEEE802.16e. To reduce the active periods of all power-saving MSSs, the base station (BS) allocates each MSS fewest possible transmission frames to retrieve its data from the BS. The BS interlaces the active periods of each MSS to increase the amount of scheduled MSSs and splits the overflowing transmission frames to maximize the bandwidth utilization. Simulation results reveal that interlacing the active periods of MSSs can increase the number of scheduled MSSs to more than four times of that in the Direct scheduling method. The bandwidth utilization can thus be improved by 60%–70%. Splitting the overflowing transmission frames can improve bandwidth utilization by more than 10% over that achieved using the method of interlacing active periods, with a sacrifice of only 1% of the sleep periods in the interlacing active period method. PMID:24523656

  17. Discrete Particle Swarm Optimization Routing Protocol for Wireless Sensor Networks with Multiple Mobile Sinks.

    PubMed

    Yang, Jin; Liu, Fagui; Cao, Jianneng; Wang, Liangming

    2016-01-01

    Mobile sinks can achieve load-balancing and energy-consumption balancing across the wireless sensor networks (WSNs). However, the frequent change of the paths between source nodes and the sinks caused by sink mobility introduces significant overhead in terms of energy and packet delays. To enhance network performance of WSNs with mobile sinks (MWSNs), we present an efficient routing strategy, which is formulated as an optimization problem and employs the particle swarm optimization algorithm (PSO) to build the optimal routing paths. However, the conventional PSO is insufficient to solve discrete routing optimization problems. Therefore, a novel greedy discrete particle swarm optimization with memory (GMDPSO) is put forward to address this problem. In the GMDPSO, particle's position and velocity of traditional PSO are redefined under discrete MWSNs scenario. Particle updating rule is also reconsidered based on the subnetwork topology of MWSNs. Besides, by improving the greedy forwarding routing, a greedy search strategy is designed to drive particles to find a better position quickly. Furthermore, searching history is memorized to accelerate convergence. Simulation results demonstrate that our new protocol significantly improves the robustness and adapts to rapid topological changes with multiple mobile sinks, while efficiently reducing the communication overhead and the energy consumption. PMID:27428971

  18. Discrete Particle Swarm Optimization Routing Protocol for Wireless Sensor Networks with Multiple Mobile Sinks.

    PubMed

    Yang, Jin; Liu, Fagui; Cao, Jianneng; Wang, Liangming

    2016-01-01

    Mobile sinks can achieve load-balancing and energy-consumption balancing across the wireless sensor networks (WSNs). However, the frequent change of the paths between source nodes and the sinks caused by sink mobility introduces significant overhead in terms of energy and packet delays. To enhance network performance of WSNs with mobile sinks (MWSNs), we present an efficient routing strategy, which is formulated as an optimization problem and employs the particle swarm optimization algorithm (PSO) to build the optimal routing paths. However, the conventional PSO is insufficient to solve discrete routing optimization problems. Therefore, a novel greedy discrete particle swarm optimization with memory (GMDPSO) is put forward to address this problem. In the GMDPSO, particle's position and velocity of traditional PSO are redefined under discrete MWSNs scenario. Particle updating rule is also reconsidered based on the subnetwork topology of MWSNs. Besides, by improving the greedy forwarding routing, a greedy search strategy is designed to drive particles to find a better position quickly. Furthermore, searching history is memorized to accelerate convergence. Simulation results demonstrate that our new protocol significantly improves the robustness and adapts to rapid topological changes with multiple mobile sinks, while efficiently reducing the communication overhead and the energy consumption.

  19. Multiple Quality-of-Service Provisioning for Non-Real-Time Services in Wireless Data Networks

    NASA Astrophysics Data System (ADS)

    Tzeng, Show-Shiow; Lu, Hsin-Yi

    2008-11-01

    One important category of network services in wireless data networks is non-real-time services. When mobile users access non-real-time services, mobile users usually care about two important points; one is whether mobile users are not forced to terminate during their lifetime, and the other is whether the total time to complete mobile users' data transfer is within their time tolerance. Low forced termination probability can be achieved through use of the technique of bandwidth adaptation which dynamically adjusts the number of bandwidths allocated to a mobile user during the mobile user's connection time. However, there is not a metric at a connection level to present the degree of the length of the total completion time. In addition, different mobile users may have different tolerances in the total completion time. In this paper, we describe a quality-of-service metric, called stretch ratio, to present the degree of the length of the total completion time. We devise a measurement based call admission control scheme that provides multiple stretch ratios for mobile users. Simulation results show that the measurement based call admission control scheme satisfies the various quality-of-service requirements of mobile users (in terms of various stretch ratios).

  20. Multiple access capacity trade-offs for a Ka-band personal access satellite system

    NASA Technical Reports Server (NTRS)

    Dessouky, Khaled; Motamedi, Masoud

    1990-01-01

    System capability is critical to the economic viability of a personal satellite communication system. Ka band has significant potential to support a high capacity multiple access system because of the availability of bandwidth. System design tradeoffs are performed and multiple access schemes are compared with the design goal of achieving the highest capacity and efficiency. Conclusions regarding the efficiency of the different schemes and the achievable capacities are given.

  1. A 30 Gb/s full-duplex bi-directional transmission optical wireless-over fiber integration system at W-band.

    PubMed

    Tang, Chanjuan; Yu, Jianjun; Li, Xinying; Chi, Nan; Xiao, Jiangnan; Tian, Yumin; Zhang, Junwen

    2014-01-13

    We propose and experimentally demonstrate a full-duplex bi-directional transmission optical wireless-over fiber integration system at W-band (75-100 GHz) with the speed up to 15 Gb/s for both 95.4 GHz link and 88.6 GHz link for the first time. The generation of millimeter-wave (mm-wave) wireless signal is based on the photonic technique by heterodyne mixing of an optical quadrature-phase-shift-keying (QPSK) signal with a free-running light at different wavelength. After 20 km fiber transmission, up to 30 Gb/s mm-wave signal is delivered over 2 m wireless link, and then converted to the optical signal for another 20 km fiber transmission. At the wireless receiver, coherent detection and advanced digital signal processing (DSP) are introduced to improve receiver sensitivity and system performance. With the OSNR of 15 dB, the bit error ratios (BERs) for 10 Gb/s signal transmission at 95.4 GHz and 88.6 GHz are below the forward-error-correction (FEC) threshold of 3.8 × 10(-3) whether post filter is used or not, while the BER for 15 Gb/s QPSK signal employing post filter in the link of 95.4 GHz is 2.9 × 10(-3).

  2. A low complexity wireless microbial fuel cell monitor using piezoresistive sensors and impulse-radio ultra-wide-band

    NASA Astrophysics Data System (ADS)

    Crepaldi, M.; Chiolerio, A.; Tommasi, T.; Hidalgo, D.; Canavese, G.; Stassi, S.; Demarchi, D.; Pirri, F. C.

    2013-05-01

    Microbial Fuel Cells (MFCs) are energy sources which generate electrical charge thanks to bacteria metabolism. Although functionally similar to chemical fuel cells (both including reactants and two electrodes, and anode and cathode), they have substantial advantages, e.g. 1) operation at ambient temperature and pressure; 2) use of neutral electrolytes and avoidance of expensive catalysts (e.g. platinum); 3) operation using organic wastes. An MFC can be effectively used in environments where ubiquitous networking requires the wireless monitoring of energy sources. We then report on a simple monitoring system for MFC comprising an ultra-low-power Impulse-Radio Ultra-Wide-Band Transmitter (TX) operating in the low 0-960MHz band and a nanostructured piezoresistive pressure sensor connected to a discrete component digital read-out circuit. The sensor comprises an insulating matrix of polydimethylsiloxane and nanostructured multi-branched copper microparticles as conductive filler. Applied mechanical stress induces a sample deformation that modulates the mean distance between particles, i.e. the current flow. The read-out circuit encodes pressure as a pulse rate variation, with an absolute sensitivity to the generated MFC voltage. Pulses with variable repetition frequency can encode battery health: the pressure sensor can be directly connected to the cells membrane to read excessive pressure. A prototype system comprises two MFCs connected in series to power both the UWB transmitter which consumes 40μW and the read-out circuit. The two MFC generate an open circuit voltage of 1.0+/-0.1V. Each MFC prototype has a total volume of 0.34L and is formed by two circular Poly(methyl methacrylate) (PMMA) chambers (anode and cathode) separated by a cation exchange membrane. The paper reports on the prototype and measurements towards a final solution which embeds all functionalities within a MFC cell. Our solution is conceived to provide energy sources integrating energy management

  3. Modeling the Multiple-Antenna Wireless Channel Using Maximum Entropy Methods

    NASA Astrophysics Data System (ADS)

    Guillaud, M.; Debbah, M.; Moustakas, A. L.

    2007-11-01

    Analytical descriptions of the statistics of wireless channel models are desirable tools for communication systems engineering. When multiple antennas are available at the transmit and/or the receive side (the Multiple-Input Multiple-Output, or MIMO, case), the statistics of the matrix H representing the gains between the antennas of a transmit and a receive antenna array, and in particular the correlation between its coefficients, are known to be of paramount importance for the design of such systems. However these characteristics depend on the operating environment, since the electromagnetic propagation paths are dictated by the surroundings of the antenna arrays, and little knowledge about these is available at the time of system design. An approach using the Maximum Entropy principle to derive probability density functions for the channel matrix, based on various degrees of knowledge about the environment, is presented. The general idea is to apply the maximum entropy principle to obtain the distribution of each parameter of interest (e.g. correlation), and then to marginalize them out to obtain the full channel distribution. It was shown in previous works, using sophisticated integrals from statistical physics, that by using the full spatial correlation matrix E{vec(H)vec(H)H} as the intermediate modeling parameter, this method can yield surprisingly concise channel descriptions. In this case, the joint probability density function is shown to be merely a function of the Frobenius norm of the channel matrix |H|F. In the present paper, we investigate the case where information about the average covariance matrix is available (e.g. through measurements). The maximum entropy distribution of the covariance is derived under this constraint. Furthermore, we consider also the doubly correlated case, where the intermediate modeling parameters are chosen as the transmit- and receive-side channel covariance matrices (respectively E{HHH} and E{HHH}). We compare the

  4. Automated Registration of Images from Multiple Bands of Resourcesat-2 Liss-4 camera

    NASA Astrophysics Data System (ADS)

    Radhadevi, P. V.; Solanki, S. S.; Jyothi, M. V.; Varadan, G.

    2014-11-01

    Continuous and automated co-registration and geo-tagging of images from multiple bands of Liss-4 camera is one of the interesting challenges of Resourcesat-2 data processing. Three arrays of the Liss-4 camera are physically separated in the focal plane in alongtrack direction. Thus, same line on the ground will be imaged by extreme bands with a time interval of as much as 2.1 seconds. During this time, the satellite would have covered a distance of about 14 km on the ground and the earth would have rotated through an angle of 30". A yaw steering is done to compensate the earth rotation effects, thus ensuring a first level registration between the bands. But this will not do a perfect co-registration because of the attitude fluctuations, satellite movement, terrain topography, PSM steering and small variations in the angular placement of the CCD lines (from the pre-launch values) in the focal plane. This paper describes an algorithm based on the viewing geometry of the satellite to do an automatic band to band registration of Liss-4 MX image of Resourcesat-2 in Level 1A. The algorithm is using the principles of photogrammetric collinearity equations. The model employs an orbit trajectory and attitude fitting with polynomials. Then, a direct geo-referencing with a global DEM with which every pixel in the middle band is mapped to a particular position on the surface of the earth with the given attitude. Attitude is estimated by interpolating measurement data obtained from star sensors and gyros, which are sampled at low frequency. When the sampling rate of attitude information is low compared to the frequency of jitter or micro-vibration, images processed by geometric correction suffer from distortion. Therefore, a set of conjugate points are identified between the bands to perform a relative attitude error estimation and correction which will ensure the internal accuracy and co-registration of bands. Accurate calculation of the exterior orientation parameters with

  5. Multi-bands photoconductive response in AlGaN/GaN multiple quantum wells

    SciTech Connect

    Chen, G.; Rong, X.; Xu, F. J.; Tang, N.; Wang, X. Q. Shen, B.; Fu, K.; Zhang, B. S.; Hashimoto, H.; Yoshikawa, A.; Ge, W. K.

    2014-04-28

    Based on the optical transitions among the quantum-confined electronic states in the conduction band, we have fabricated multi-bands AlGaN/GaN quantum well infrared photodetectors. Crack-free AlGaN/GaN multiple quantum wells (MQWs) with atomically sharp interfaces have been achieved by inserting an AlN interlayer, which releases most of the tensile strain in the MQWs grown on the GaN underlayer. With significant reduction of dark current by using thick AlGaN barriers, photoconductive responses are demonstrated due to intersubband transition in multiple regions with center wavelengths of 1.3, 2.3, and 4 μm, which shows potential applications on near infrared detection.

  6. Performance evaluation of modulation and multiple access schemes in ultraviolet optical wireless connections for two atmosphere thickness cases.

    PubMed

    Raptis, Nikos; Pikasis, Evangelos; Syvridis, Dimitris

    2016-08-01

    The exploitation of optical wireless communication channels in a non-line-of-sight regime is studied for point-to-point and networking configurations considering the use of light-emitting diodes. Two environments with different scattering center densities are considered, assuming operation at 265 nm. The bit error rate performance of both pulsed and multicarrier modulation schemes is examined, using numerical approaches. In the networking scenario, a central node only receives data, one node transmits useful data, and the rest of them act as interferers. The performance of the desirable node's transmissions is evaluated. The access to the medium is controlled by a code division multiple access scheme. PMID:27505663

  7. Performance evaluation of modulation and multiple access schemes in ultraviolet optical wireless connections for two atmosphere thickness cases.

    PubMed

    Raptis, Nikos; Pikasis, Evangelos; Syvridis, Dimitris

    2016-08-01

    The exploitation of optical wireless communication channels in a non-line-of-sight regime is studied for point-to-point and networking configurations considering the use of light-emitting diodes. Two environments with different scattering center densities are considered, assuming operation at 265 nm. The bit error rate performance of both pulsed and multicarrier modulation schemes is examined, using numerical approaches. In the networking scenario, a central node only receives data, one node transmits useful data, and the rest of them act as interferers. The performance of the desirable node's transmissions is evaluated. The access to the medium is controlled by a code division multiple access scheme.

  8. Analysis and Testing of Mobile Wireless Networks

    NASA Technical Reports Server (NTRS)

    Alena, Richard; Evenson, Darin; Rundquist, Victor; Clancy, Daniel (Technical Monitor)

    2002-01-01

    Wireless networks are being used to connect mobile computing elements in more applications as the technology matures. There are now many products (such as 802.11 and 802.11b) which ran in the ISM frequency band and comply with wireless network standards. They are being used increasingly to link mobile Intranet into Wired networks. Standard methods of analyzing and testing their performance and compatibility are needed to determine the limits of the technology. This paper presents analytical and experimental methods of determining network throughput, range and coverage, and interference sources. Both radio frequency (BE) domain and network domain analysis have been applied to determine wireless network throughput and range in the outdoor environment- Comparison of field test data taken under optimal conditions, with performance predicted from RF analysis, yielded quantitative results applicable to future designs. Layering multiple wireless network- sooners can increase performance. Wireless network components can be set to different radio frequency-hopping sequences or spreading functions, allowing more than one sooner to coexist. Therefore, we ran multiple 802.11-compliant systems concurrently in the same geographical area to determine interference effects and scalability, The results can be used to design of more robust networks which have multiple layers of wireless data communication paths and provide increased throughput overall.

  9. 78 FR 31472 - Wireless Telecommunications Bureau Seeks To Supplement the Record on the 600 MHz Band Plan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-24

    ... Comment Filing System (ECFS). See Electronic Filing of Documents in Rulemaking Proceedings, 63 FR 24121... Economic and Innovation Opportunities of Spectrum Through Incentive Auctions 77 FR 69934 November 21, 2012... be adjacent to radio astronomy (RA) and wireless medical telemetry services (WMTS) operations...

  10. Tunable Symmetries of Integer and Fractional Quantum Hall Phases in Heterostructures with Multiple Dirac Bands

    NASA Astrophysics Data System (ADS)

    Stepanov, Petr; Barlas, Yafis; Espiritu, Tim; Che, Shi; Watanabe, Kenji; Taniguchi, Takashi; Smirnov, Dmitry; Lau, Chun Ning

    2016-08-01

    The copresence of multiple Dirac bands in few-layer graphene leads to a rich phase diagram in the quantum Hall regime. Using transport measurements, we map the phase diagram of BN-encapsulated A B A -stacked trilayer graphene as a function charge density n , magnetic field B , and interlayer displacement field D , and observe transitions among states with different spin, valley, orbital, and parity polarizations. Such a rich pattern arises from crossings between Landau levels from different subbands, which reflect the evolving symmetries that are tunable in situ. At D =0 , we observe fractional quantum Hall (FQH) states at filling factors 2 /3 and -11 /3 . Unlike those in bilayer graphene, these FQH states are destabilized by a small interlayer potential that hybridizes the different Dirac bands.

  11. Tunable Symmetries of Integer and Fractional Quantum Hall Phases in Heterostructures with Multiple Dirac Bands.

    PubMed

    Stepanov, Petr; Barlas, Yafis; Espiritu, Tim; Che, Shi; Watanabe, Kenji; Taniguchi, Takashi; Smirnov, Dmitry; Lau, Chun Ning

    2016-08-12

    The copresence of multiple Dirac bands in few-layer graphene leads to a rich phase diagram in the quantum Hall regime. Using transport measurements, we map the phase diagram of BN-encapsulated ABA-stacked trilayer graphene as a function charge density n, magnetic field B, and interlayer displacement field D, and observe transitions among states with different spin, valley, orbital, and parity polarizations. Such a rich pattern arises from crossings between Landau levels from different subbands, which reflect the evolving symmetries that are tunable in situ. At D=0, we observe fractional quantum Hall (FQH) states at filling factors 2/3 and -11/3. Unlike those in bilayer graphene, these FQH states are destabilized by a small interlayer potential that hybridizes the different Dirac bands. PMID:27563989

  12. Optimized Sharable-Slot Allocation Using Multiple Channels to Reduce Data-Gathering Delay in Wireless Sensor Networks

    PubMed Central

    Van Vinh, Phan; Oh, Hoon

    2016-01-01

    The demand for event-driven real-time applications for timely and reliable data acquisition is growing in industrial sectors. However, it is challenging to satisfy the requirements since constraints such as limited available energy and bandwidth are inherent in a wireless sensor network. To deal with timely delivery, one desirable approach is to improve network throughput so that more real-time applications with tighter time constraints can be satisfied in any given network. To deal with reliable delivery, the use of a carrier sense multiple access mechanism for data transmission is preferred, along with the use of a sharable slot within which multiple nodes compete to send data. Thus, we present a method of using multiple channels and a way to optimize the size of the sharable slot. The proposed channel-slot–scheduling algorithm tries to optimize the size of a sharable slot when multiple channels are used. The algorithm also deals with situations where nodes generate multiple data packets in each round of a data-gathering period. It is shown through simulation that our approach greatly outperforms others on some selected metrics. PMID:27070619

  13. A 400G optical wireless integration delivery system.

    PubMed

    Li, Xinying; Yu, Jianjun; Zhang, Junwen; Dong, Ze; Li, Fan; Chi, Nan

    2013-08-12

    We experimentally demonstrate a record 400G optical wireless integration system simultaneously delivering 2 × 112 Gb/s two-channel polarization-division-multiplexing 16-ary quadrature amplitude modulation (PDM-16QAM) signal at 37.5 GHz wireless carrier and 2 × 108 Gb/s two-channel PDM quadrature phase shift keying (PDM-QPSK) signal at 100 GHz wireless carrier, adopting two millimeter-wave (mm-wave) frequency bands, two orthogonal antenna polarizations, multiple-input multiple-output (MIMO), photonic mm-wave generation and advanced digital signal processing (DSP). In the case of no fiber transmission, the bit error ratios (BERs) for both the 112 Gb/s PDM-16QAM signal after 1.5 m wireless delivery at 37.5 GHz and the 108 Gb/s PDM-QPSK signal after 0.7 m wireless delivery at 100 GHz are below the pre-forward-error-correction (pre-FEC) threshold of 3.8 × 10(-3). To our knowledge, this is the first demonstration of a 400G optical wireless integration system in mm-wave frequency bands and also a capacity record of wireless delivery.

  14. Contextually sensitive power changes across multiple frequency bands underpin cognitive control.

    PubMed

    Cooper, Patrick S; Darriba, Álvaro; Karayanidis, Frini; Barceló, Francisco

    2016-05-15

    Flexible control of cognition bestows a remarkable adaptability to a broad range of contexts. While cognitive control is known to rely on frontoparietal neural architecture to achieve this flexibility, the neural mechanisms that allow such adaptability to context are poorly understood. In the current study, we quantified contextual demands on the cognitive control system via a priori estimation of information across three tasks varying in difficulty (oddball, go/nogo, and switch tasks) and compared neural responses across these different contexts. We report evidence of the involvement of multiple frequency bands during preparation and implementation of cognitive control. Specifically, a common frontoparietal delta and a central alpha process corresponded to rule implementation and motor response respectively. Interestingly, we found evidence of a frontal theta signature that was sensitive to increasing amounts of information and a posterior parietal alpha process only seen during anticipatory rule updating. Importantly, these neural signatures of context processing match proposed frontal hierarchies of control and together provide novel evidence of a complex interplay of multiple frequency bands underpinning flexible, contextually sensitive cognition. PMID:26975557

  15. L-band and SHF multiple access schemes for the MSAT system

    NASA Technical Reports Server (NTRS)

    Razi, Michael; Shoamanesh, Alireza; Azarbar, Bahman

    1988-01-01

    The first generation of the Canadian Mobile Satellite (MSAT) system, planned to be operational in the early 1990s, will provide voice and data services to land, aeronautical, and maritime mobile terminals within the Canadian land mass and its territorial waters. The system will be managed by a centralized Demand Assignment Multiple Access (DAMA) control system. Users will request a communication channel by communicating with the DAMA Control System (DCS) via the appropriate signalling channels. Several access techniques for both L-band and SHF signalling channels have been investigated. For the L-band, Slotted Aloha (SA) and Reservation Aloha (RA), combined with a token scheme, are discussed here. The results of Telesat studies to date indicate that SA, when combined with token scheme, provides the most efficient access and resource management tool in a mobile propagation environment. For SHF signalling channels, slim time division multiple access (TDMA) and SA have been considered as the most suitable candidate schemes. In view of the operational environment of the SHF links, provision of a very short channel access delay and a relatively high packet success rate are highly desirable. Studies carried out generally favor slim-TDMA as the most suitable approach for SHF signalling channels.

  16. Contextually sensitive power changes across multiple frequency bands underpin cognitive control.

    PubMed

    Cooper, Patrick S; Darriba, Álvaro; Karayanidis, Frini; Barceló, Francisco

    2016-05-15

    Flexible control of cognition bestows a remarkable adaptability to a broad range of contexts. While cognitive control is known to rely on frontoparietal neural architecture to achieve this flexibility, the neural mechanisms that allow such adaptability to context are poorly understood. In the current study, we quantified contextual demands on the cognitive control system via a priori estimation of information across three tasks varying in difficulty (oddball, go/nogo, and switch tasks) and compared neural responses across these different contexts. We report evidence of the involvement of multiple frequency bands during preparation and implementation of cognitive control. Specifically, a common frontoparietal delta and a central alpha process corresponded to rule implementation and motor response respectively. Interestingly, we found evidence of a frontal theta signature that was sensitive to increasing amounts of information and a posterior parietal alpha process only seen during anticipatory rule updating. Importantly, these neural signatures of context processing match proposed frontal hierarchies of control and together provide novel evidence of a complex interplay of multiple frequency bands underpinning flexible, contextually sensitive cognition.

  17. 76 FR 67070 - Operation of Wireless Communications Services in the 2.3 GHz Band; Establishment of Rules and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-31

    ...), 27.73(a), and 27.73(b) of the Commission's rules published at 75 FR 45058, August 2, 2010, are... and Policies for the Digital Audio Radio Satellite Service in the 2310-2360 MHz Frequency Band AGENCY... Audio Radio Satellite Service in the 2310-2360 MHz Frequency Band (WCS and SDARS) proceeding, to...

  18. 78 FR 77029 - Wireless Telecommunications Bureau Seeks Comment on a Proposal To License the 600 MHz Band Using...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... 77 FR 69934 November 21, 2012 (NPRM), the Commission sought public comment on creating a 600 MHz band... MHz Bands 78 FR 51559 August 20, 2013 (AWS-3 NPRM), WTB seeks comment on applying this approach. 4. As... Electronic Comment Filing System (ECFS). See Electronic Filing of Documents in Rulemaking Proceedings, 63...

  19. 2  ×  2 multiple-input multiple-output optical-wireless integration system based on optical independent-sideband modulation enabled by an in-phase/quadrature modulator.

    PubMed

    Li, Xinying; Yu, Jianjun

    2016-07-01

    We propose a novel and simple 2×2 multiple-input multiple-output (MIMO) optical-wireless integration system, in which optical independent-sideband modulation enabled by an in-phase/quadrature (I/Q) modulator, instead of optical polarization multiplexing, is used to assist the simultaneous generation of two wireless millimeter-wave (mm-wave) signals. Software-based digital signal processing is used to generate the driving signal for the I/Q modulator, the output of which is two independent single-sideband optical vector signals located at two sides of a large central optical carrier. Based on our proposed 2×2 MIMO optical-wireless integration system, we experimentally demonstrate the simultaneous generation and 2×2 MIMO wireless delivery of two independent 40-GHz quadrature-phase-shift-keying (QPSK) wireless mm-wave signals. Each 40-GHz QPSK wireless mm-wave signal can carry up to 4-Gbaud transmitter data with a bit-error ratio less than the hard-decision forward-error-correction threshold of 3.8×10-3.

  20. Traffic Regulation on Wireless 802.11 Networks Using Multiple Queue Technique

    NASA Astrophysics Data System (ADS)

    Dhanal, Radhika J.; Patil, G. A.

    2010-11-01

    WLAN technologies are becoming increasingly popular and are platform for many future applications. IEEE 802.11 Wireless LAN (WLAN) is an excellent solution for the broadband wireless networking. This paper presents a simple approach to enhance the performance of real time (RT) and non-real time (NRT) services over the 802.11 WLAN by using some special queues. This requires the system to first identify the type of service and then use the appropriate scheduling algorithm. The admission control algorithm is used first to determine the admission of particular station. Deficit round robin algorithm is used to set the priorities to RT and NRT packets in order to increase the QoS of WLAN. So we can combine both these algorithms by implementing them one after another. The proposed scheme can improve Voice/Data/Video services through simple software upgrades by reducing the delay, jitter and increasing the throughput. Through simulation, we show that the proposed scheme can give better QoS than existing schemes.

  1. A modular wireless in vivo surgical robot with multiple surgical applications.

    PubMed

    Hawks, Jeff A; Rentschler, Mark E; Farritor, Shane; Oleynikov, Dmitry; Platt, Stephen R

    2009-01-01

    The use of miniature in vivo robots that fit entirely inside the peritoneal cavity represents a novel approach to laparoscopic surgery. Previous work demonstrates that both mobile and fixed-based robots can successfully operate inside the abdominal cavity. A modular wireless mobile platform has also been developed to provide surgical vision and task assistance. This paper presents an overview of recent test results of several possible surgical applications that can be accommodated by this modular platform. Applications such as a biopsy grasper, stapler and clamp, video camera, and physiological sensors have been integrated into the wireless platform and tested in vivo in a porcine model. The modular platform facilitates rapid development and conversion from one type of surgical task assistance to another. These self-contained surgical devices are much more transportable and much lower in cost than current robotic surgical assistants. These devices could ultimately be carried and deployed by non-medical personnel at the site of an injury. A remotely located surgeon could use these robots to provide critical first response medical intervention.

  2. Experiments on multiple-receiver magnetic resonance-based wireless power transfer in low megahertz with metamaterials

    NASA Astrophysics Data System (ADS)

    Kang, Le; Hu, Yuli; Zheng, Wei

    2016-04-01

    In this paper, an efficient magnetic resonance-based wireless power transfer (MRWPT) system with metamaterials is proposed. The negative permeability (MNG) metamaterials for this system with low-megahertz frequency is designed, which can be adjusted to work well at a variable receiving angle ranging from 0° to 45° along z-direction. The S-parameters, resonant frequency and permeability of metamaterials are computed for analysis. The transmission efficiency of the multiple-receiver MRWPT system in free space is compared to that in the presence of metamaterials placed in front of transmission and receive coils. The measured results show that the performance of the proposed metamaterials is perfect in improving the efficiency with incident electromagnetic waves from various directions.

  3. Statistical mechanical analysis of the Kronecker channel model for multiple-input multiple-output wireless communication.

    PubMed

    Hatabu, Atsushi; Takeda, Koujin; Kabashima, Yoshiyuki

    2009-12-01

    The Kronecker channel model of wireless communication is analyzed using statistical mechanics methods. In the model, spatial proximities among transmission/reception antennas are taken into account as certain correlation matrices, which generally yield nontrivial dependence among symbols to be estimated. This prevents accurate assessment of the communication performance by naively using a previously developed analytical scheme based on a matrix integration formula. In order to resolve this difficulty, we develop a formalism that can formally handle the correlations in Kronecker models based on the known scheme. Unfortunately, direct application of the developed scheme is, in general, practically difficult. However, the formalism is still useful, indicating that the effect of the correlations generally increase after the fourth order with respect to correlation strength. Therefore, the known analytical scheme offers a good approximation in performance evaluation when the correlation strength is sufficiently small. For a class of specific correlation, we show that the performance analysis can be mapped to the problem of one-dimensional spin systems in random fields, which can be investigated without approximation by the belief propagation algorithm.

  4. 78 FR 9605 - Operation of Wireless Communications Services in the 2.3 GHz Band; Establishment of Rules and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ...) and aeronautical mobile telemetry (AMT) operations in adjacent bands and the deep space network (DSN... and SDARS 2nd R&O, 75 FR 45058, August 2, 2010, filed by ARRL, the national association for...

  5. Carrier Multiplication in Semiconductor Nanocrystals: Theoretical Screening of Candidate Materials Based on Band-Structure Effects

    SciTech Connect

    Luo, J. W.; Franceschetti, A.; Zunger, A.

    2008-01-01

    Direct carrier multiplication (DCM) occurs when a highly excited electron-hole pair decays by transferring its excess energy to the electrons rather than to the lattice, possibly exciting additional electron-hole pairs. Atomistic electronic structure calculations have shown that DCM can be induced by electron-hole Coulomb interactions, in an impact-ionization-like process whose rate is proportional to the density of biexciton states {rho}{sub XX}. Here we introduce a DCM 'figure of merit' R{sub 2}(E) which is proportional to the ratio between the biexciton density of states {rho}{sub XX} and the single-exciton density of states {rho}{sub x}, restricted to single-exciton and biexciton states that are coupled by Coulomb interactions. Using R{sub 2}(E), we consider GaAs, InAs, InP, GaSb, InSb, CdSe, Ge, Si, and PbSe nanocrystals of different sizes. Although DCM can be affected by both quantum-confinement effects (reflecting the underly electronic structure of the confined dot-interior states) and surface effects, here we are interested to isolate the former. To this end the nanocrystal energy levels are obtained from the corresponding bulk band structure via the truncated crystal approximation. We find that PbSe, Si, GaAs, CdSe, and InP nanocrystals have larger DCM figure of merit than the other nanocrystals. Our calculations suggest that high DCM efficiency requires high degeneracy of the corresponding bulk band-edge states. Interestingly, by considering band structure effects we find that as the dot size increases the DCM critical energy E{sub 0} (the energy at which R{sub 2}(E) becomes {ge}1) is reduced, suggesting improved DCM. However, whether the normalized E{sub 0}/{var_epsilon}{sub g} increases or decreases as the dot size increases depends on dot material.

  6. Learning Multiple Band-Pass Filters for Sleep Stage Estimation: Towards Care Support for Aged Persons

    NASA Astrophysics Data System (ADS)

    Takadama, Keiki; Hirose, Kazuyuki; Matsushima, Hiroyasu; Hattori, Kiyohiko; Nakajima, Nobuo

    This paper proposes the sleep stage estimation method that can provide an accurate estimation for each person without connecting any devices to human's body. In particular, our method learns the appropriate multiple band-pass filters to extract the specific wave pattern of heartbeat, which is required to estimate the sleep stage. For an accurate estimation, this paper employs Learning Classifier System (LCS) as the data-mining techniques and extends it to estimate the sleep stage. Extensive experiments on five subjects in mixed health confirm the following implications: (1) the proposed method can provide more accurate sleep stage estimation than the conventional method, and (2) the sleep stage estimation calculated by the proposed method is robust regardless of the physical condition of the subject.

  7. S-band multiple-access interference study for advanced tracking and data relay satellite systems

    NASA Technical Reports Server (NTRS)

    Peng, Wei-Chung; Yang, Chau-Chin

    1990-01-01

    The results of a study on the effect of mutual interference among S-band multiple access (SMA) system users of advanced tracking and data relay satellite system (ATDRSS) are presented. In the ATDRSS era, the SMA system is required to support data rates ranging from 10 kb/s to 3 Mb/s. The system will consist of four advanced tracking and data relay satellites (ATDRS) each supporting up to five telemetry links. All users have 10 MHz bandwidth with their carrier frequency equal to 2.2875 GHz. A hybrid SDMA/CDMA scheme is used to mitigate the effect of the interference among system users. SMA system interference probability is evaluated with CLASS software. User link margin degradation due to mutual interference between two users is evaluated. System interference probability is evaluated for the projected 1996 mission model, a reference mission model, and a modified reference mission model.

  8. Systematic topology optimization of solid-solid phononic crystals for multiple separate band-gaps with different polarizations.

    PubMed

    Liu, Zong-Fa; Wu, Bin; He, Cun-Fu

    2016-02-01

    Phononic crystals (PnCs) have attracted considerable interest due to their unique and outstanding band-gap characteristics. In many applications, it is desirable to have a unit cell with specific band-gaps. The distribution of elastic materials within a unit cell has significant effect on the band-gaps, which is extremely difficult to be determined without systematic synthesis method. In this paper, topology optimization techniques are utilized to obtain two-dimensional (2D) square lattice PnCs with maximized relative band-gaps between multiple consecutive bands. The optimization follows two-stage design process using Genetic algorithms (GAs) in combination with finite element method (FEM). Three numerical examples are given to optimize 2D steel/epoxy PnCs in one-eighth symmetry for coupled mode, shear mode and mixed mode respectively. The results show that the optimized PnCs with different band-gaps, which can easily be found by the developed method, have different materials layout, and the PnCs with the lowest order band-gap are simple lattice and have the highest value of application in noise reduction and vibration isolation. Some optimized PnCs with higher order band-gaps have the same lattice as those with the lowest order band-gap, and whose absolute band-gaps are inversely proportional to the minimum feature size of primitive cells. PMID:26456279

  9. Multiple-band reflective polarization converter using U-shaped metamaterial

    SciTech Connect

    Huang, Xiaojun; Yang, Dong; Yang, Helin

    2014-03-14

    A multiple-band metamaterial reflective polarization converter (RPC) is proposed, which is composed of the dielectric substrate sandwiched with U-shaped metallic patterns and continuous metal film. The proposed U-shaped metamaterial RPC (UMM-RPC) can convert a linearly polarized wave to its cross polarized wave at the three resonant frequencies, which also can convert the linearly polarized wave to circularly polarized wave at other three resonant frequencies. Furthermore, the proposed UMM-RPC can maintain the same conversional direction at the three resonant frequencies when incident on a circularly polarized wave. The simulated and measured results are in agreement in the entire frequency range, and the polarization conversion ratio is over 90% for both linear and circular polarizations. The surface current distributions of the UMM-RPC are discussed to look into the physical mechanism. The proposed UMM-RPC has simple geometry but more operating frequency bands compared to the previous designs and can be used in applications such as antenna radome, remote sensors, and radiometer.

  10. Multiple-band reflective polarization converter using U-shaped metamaterial

    NASA Astrophysics Data System (ADS)

    Huang, Xiaojun; Yang, Dong; Yang, Helin

    2014-03-01

    A multiple-band metamaterial reflective polarization converter (RPC) is proposed, which is composed of the dielectric substrate sandwiched with U-shaped metallic patterns and continuous metal film. The proposed U-shaped metamaterial RPC (UMM-RPC) can convert a linearly polarized wave to its cross polarized wave at the three resonant frequencies, which also can convert the linearly polarized wave to circularly polarized wave at other three resonant frequencies. Furthermore, the proposed UMM-RPC can maintain the same conversional direction at the three resonant frequencies when incident on a circularly polarized wave. The simulated and measured results are in agreement in the entire frequency range, and the polarization conversion ratio is over 90% for both linear and circular polarizations. The surface current distributions of the UMM-RPC are discussed to look into the physical mechanism. The proposed UMM-RPC has simple geometry but more operating frequency bands compared to the previous designs and can be used in applications such as antenna radome, remote sensors, and radiometer.

  11. Magnetotransport of multiple-band nearly antiferromagnetic metals due to hot-spot scattering

    NASA Astrophysics Data System (ADS)

    Koshelev, A. E.

    2016-09-01

    Multiple-band electronic structure and proximity to antiferromagnetic (AF) instability are the key properties of iron-based superconductors. We explore the influence of scattering by the AF spin fluctuations on transport of multiple-band metals above the magnetic transition. A salient feature of scattering on the AF fluctuations is that it is strongly enhanced at the Fermi surface locations where the nesting is perfect ("hot spots" or "hot lines"). We review derivation of the collision integral for the Boltzmann equation due to AF-fluctuations scattering. In the paramagnetic state, the enhanced scattering rate near the hot lines leads to anomalous behavior of electronic transport in magnetic field. We explore this behavior by analytically solving the Boltzmann transport equation with approximate transition rates. This approach accounts for return scattering events and is more accurate than the relaxation-time approximation. The magnetic-field dependences are characterized by two very different field scales: the lower scale is set by the hot-spot width and the higher scale is set by the total scattering amplitude. A conventional magnetotransport behavior is limited to magnetic fields below the lower scale. In the wide range in-between these two scales, the longitudinal conductivity has linear dependence on the magnetic field and the Hall conductivity has quadratic dependence. The linear dependence of the diagonal component reflects growth of the Fermi-surface area affected by the hot spots proportional to the magnetic field. We discuss applicability of this theoretical framework for describing of anomalous magnetotransport properties in different iron pnictides and chalcogenides in the paramagnetic state.

  12. Embedding multiple watermarks in the DFT domain using low- and high-frequency bands

    NASA Astrophysics Data System (ADS)

    Ganic, Emir; Dexter, Scott D.; Eskicioglu, Ahmet M.

    2005-03-01

    Although semi-blind and blind watermarking schemes based on Discrete Cosine Transform (DCT) or Discrete Wavelet Transform (DWT) are robust to a number of attacks, they fail in the presence of geometric attacks such as rotation, scaling, and translation. The Discrete Fourier Transform (DFT) of a real image is conjugate symmetric, resulting in a symmetric DFT spectrum. Because of this property, the popularity of DFT-based watermarking has increased in the last few years. In a recent paper, we generalized a circular watermarking idea to embed multiple watermarks in lower and higher frequencies. Nevertheless, a circular watermark is visible in the DFT domain, providing a potential hacker with valuable information about the location of the watermark. In this paper, our focus is on embedding multiple watermarks that are not visible in the DFT domain. Using several frequency bands increases the overall robustness of the proposed watermarking scheme. Specifically, our experiments show that the watermark embedded in lower frequencies is robust to one set of attacks, and the watermark embedded in higher frequencies is robust to a different set of attacks.

  13. A wireless sensor enabled by wireless power.

    PubMed

    Lee, Da-Sheng; Liu, Yu-Hong; Lin, Chii-Ruey

    2012-11-22

    Through harvesting energy by wireless charging and delivering data by wireless communication, this study proposes the concept of a wireless sensor enabled by wireless power (WPWS) and reports the fabrication of a prototype for functional tests. One WPWS node consists of wireless power module and sensor module with different chip-type sensors. Its main feature is the dual antenna structure. Following RFID system architecture, a power harvesting antenna was designed to gather power from a standard reader working in the 915 MHz band. Referring to the Modbus protocol, the other wireless communication antenna was integrated on a node to send sensor data in parallel. The dual antenna structure integrates both the advantages of an RFID system and a wireless sensor. Using a standard UHF RFID reader, WPWS can be enabled in a distributed area with a diameter up to 4 m. Working status is similar to that of a passive tag, except that a tag can only be queried statically, while the WPWS can send dynamic data from the sensors. The function is the same as a wireless sensor node. Different WPWSs equipped with temperature and humidity, optical and airflow velocity sensors are tested in this study. All sensors can send back detection data within 8 s. The accuracy is within 8% deviation compared with laboratory equipment. A wireless sensor network enabled by wireless power should be a totally wireless sensor network using WPWS. However, distributed WPWSs only can form a star topology, the simplest topology for constructing a sensor network. Because of shielding effects, it is difficult to apply other complex topologies. Despite this limitation, WPWS still can be used to extend sensor network applications in hazardous environments. Further research is needed to improve WPWS to realize a totally wireless sensor network.

  14. A wireless sensor enabled by wireless power.

    PubMed

    Lee, Da-Sheng; Liu, Yu-Hong; Lin, Chii-Ruey

    2012-01-01

    Through harvesting energy by wireless charging and delivering data by wireless communication, this study proposes the concept of a wireless sensor enabled by wireless power (WPWS) and reports the fabrication of a prototype for functional tests. One WPWS node consists of wireless power module and sensor module with different chip-type sensors. Its main feature is the dual antenna structure. Following RFID system architecture, a power harvesting antenna was designed to gather power from a standard reader working in the 915 MHz band. Referring to the Modbus protocol, the other wireless communication antenna was integrated on a node to send sensor data in parallel. The dual antenna structure integrates both the advantages of an RFID system and a wireless sensor. Using a standard UHF RFID reader, WPWS can be enabled in a distributed area with a diameter up to 4 m. Working status is similar to that of a passive tag, except that a tag can only be queried statically, while the WPWS can send dynamic data from the sensors. The function is the same as a wireless sensor node. Different WPWSs equipped with temperature and humidity, optical and airflow velocity sensors are tested in this study. All sensors can send back detection data within 8 s. The accuracy is within 8% deviation compared with laboratory equipment. A wireless sensor network enabled by wireless power should be a totally wireless sensor network using WPWS. However, distributed WPWSs only can form a star topology, the simplest topology for constructing a sensor network. Because of shielding effects, it is difficult to apply other complex topologies. Despite this limitation, WPWS still can be used to extend sensor network applications in hazardous environments. Further research is needed to improve WPWS to realize a totally wireless sensor network. PMID:23443370

  15. A Wireless Sensor Enabled by Wireless Power

    PubMed Central

    Lee, Da-Sheng; Liu, Yu-Hong; Lin, Chii-Ruey

    2012-01-01

    Through harvesting energy by wireless charging and delivering data by wireless communication, this study proposes the concept of a wireless sensor enabled by wireless power (WPWS) and reports the fabrication of a prototype for functional tests. One WPWS node consists of wireless power module and sensor module with different chip-type sensors. Its main feature is the dual antenna structure. Following RFID system architecture, a power harvesting antenna was designed to gather power from a standard reader working in the 915 MHz band. Referring to the Modbus protocol, the other wireless communication antenna was integrated on a node to send sensor data in parallel. The dual antenna structure integrates both the advantages of an RFID system and a wireless sensor. Using a standard UHF RFID reader, WPWS can be enabled in a distributed area with a diameter up to 4 m. Working status is similar to that of a passive tag, except that a tag can only be queried statically, while the WPWS can send dynamic data from the sensors. The function is the same as a wireless sensor node. Different WPWSs equipped with temperature and humidity, optical and airflow velocity sensors are tested in this study. All sensors can send back detection data within 8 s. The accuracy is within 8% deviation compared with laboratory equipment. A wireless sensor network enabled by wireless power should be a totally wireless sensor network using WPWS. However, distributed WPWSs only can form a star topology, the simplest topology for constructing a sensor network. Because of shielding effects, it is difficult to apply other complex topologies. Despite this limitation, WPWS still can be used to extend sensor network applications in hazardous environments. Further research is needed to improve WPWS to realize a totally wireless sensor network. PMID:23443370

  16. 78 FR 70237 - Operation of Wireless Communications Services in the 2.3 GHz Band; Establishment of Rules and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-25

    ... effective date of those rules. DATES: 47 CFR 27.72(b) and 47 CFR 27.73(a), published at 78 FR 9605, February... stimulation rules contained in the Commission's Order on Reconsideration, FCC 12- 130, published at 78 FR 9605... Policies for the Digital Audio Radio Satellite Service in the 2310-2360 MHz Frequency Band AGENCY:...

  17. Multiple-resolution study of Ka-band HRR polarimetric signature data

    NASA Astrophysics Data System (ADS)

    Giles, Robert H.; Kersey, William T.; McFarlin, M. Shane; Woodruff, Bobby G.; Finley, Robbin; Nixon, William E.

    2000-08-01

    SAR resolution and polarization performance studies for ATR algorithms have been the source of recent attention. Thorough investigations are often hindered by the lack of rigorously consistent high-resolution full-polarimetric signature data for a sufficient number of targets across requisite viewing angles, articulations and environmental conditions. While some evaluative performance studies of high-value structures and conceptual radar systems may be effectively studied with limited field radar data, to minimize signature acquisition costs, pose-independent studies of ATR algorithm are best served by signature libraries fashioned to encompass the complexity of the collection scenario. In response to the above requirements, the U.S. Army's National Ground Intelligence Center and Targets Management Office originated, sponsored, and directed a signature project plan to acquire multiple target signature data at Eglin, AFB using a high resolution full-polarimetric Ka-band radar. TMO and NGIC have sponsored researchers at both the Submillimeter-Wave Technology Laboratory and Simulation Technologies to analyze the trade-off between signature resolution and polarimetric features (ongoing research) of this turntable data. The signature data was acquired at five elevations spanning 5 degree to 60 degree for a T-72M1, T-72B, M1, M60-A3 and one classified vehicle. Using signal processing software established in an NGIC/STL-based signature study, researchers executed an HRR and ISAR cross-correlation study involving multiple resolutions to evaluate peak performance levels and to effectively understand signature requirements through the variability of multiple target RCS characteristics. The signature-to-signature variability quantified on the four unclassified MBTs is presented in this report, along with a description and examples of the signature analysis techniques exploited. This signature data is available from NGIC/TMO on request for Government Agencies and Government

  18. Modeling and Simulation of a Novel Relay Node Based Secure Routing Protocol Using Multiple Mobile Sink for Wireless Sensor Networks

    PubMed Central

    Perumal, Madhumathy; Dhandapani, Sivakumar

    2015-01-01

    Data gathering and optimal path selection for wireless sensor networks (WSN) using existing protocols result in collision. Increase in collision further increases the possibility of packet drop. Thus there is a necessity to eliminate collision during data aggregation. Increasing the efficiency is the need of the hour with maximum security. This paper is an effort to come up with a reliable and energy efficient WSN routing and secure protocol with minimum delay. This technique is named as relay node based secure routing protocol for multiple mobile sink (RSRPMS). This protocol finds the rendezvous point for optimal transmission of data using a “splitting tree” technique in tree-shaped network topology and then to determine all the subsequent positions of a sink the “Biased Random Walk” model is used. In case of an event, the sink gathers the data from all sources, when they are in the sensing range of rendezvous point. Otherwise relay node is selected from its neighbor to transfer packets from rendezvous point to sink. A symmetric key cryptography is used for secure transmission. The proposed relay node based secure routing protocol for multiple mobile sink (RSRPMS) is experimented and simulation results are compared with Intelligent Agent-Based Routing (IAR) protocol to prove that there is increase in the network lifetime compared with other routing protocols. PMID:26495426

  19. Modeling and Simulation of a Novel Relay Node Based Secure Routing Protocol Using Multiple Mobile Sink for Wireless Sensor Networks.

    PubMed

    Perumal, Madhumathy; Dhandapani, Sivakumar

    2015-01-01

    Data gathering and optimal path selection for wireless sensor networks (WSN) using existing protocols result in collision. Increase in collision further increases the possibility of packet drop. Thus there is a necessity to eliminate collision during data aggregation. Increasing the efficiency is the need of the hour with maximum security. This paper is an effort to come up with a reliable and energy efficient WSN routing and secure protocol with minimum delay. This technique is named as relay node based secure routing protocol for multiple mobile sink (RSRPMS). This protocol finds the rendezvous point for optimal transmission of data using a "splitting tree" technique in tree-shaped network topology and then to determine all the subsequent positions of a sink the "Biased Random Walk" model is used. In case of an event, the sink gathers the data from all sources, when they are in the sensing range of rendezvous point. Otherwise relay node is selected from its neighbor to transfer packets from rendezvous point to sink. A symmetric key cryptography is used for secure transmission. The proposed relay node based secure routing protocol for multiple mobile sink (RSRPMS) is experimented and simulation results are compared with Intelligent Agent-Based Routing (IAR) protocol to prove that there is increase in the network lifetime compared with other routing protocols. PMID:26495426

  20. Defining Multiple Characteristic Raman Bands of α-Amino Acids as Biomarkers for Planetary Missions Using a Statistical Method

    NASA Astrophysics Data System (ADS)

    Rolfe, S. M.; Patel, M. R.; Gilmour, I.; Olsson-Francis, K.; Ringrose, T. J.

    2016-06-01

    Biomarker molecules, such as amino acids, are key to discovering whether life exists elsewhere in the Solar System. Raman spectroscopy, a technique capable of detecting biomarkers, will be on board future planetary missions including the ExoMars rover. Generally, the position of the strongest band in the spectra of amino acids is reported as the identifying band. However, for an unknown sample, it is desirable to define multiple characteristic bands for molecules to avoid any ambiguous identification. To date, there has been no definition of multiple characteristic bands for amino acids of interest to astrobiology. This study examined l-alanine, l-aspartic acid, l-cysteine, l-glutamine and glycine and defined several Raman bands per molecule for reference as characteristic identifiers. Per amino acid, 240 spectra were recorded and compared using established statistical tests including ANOVA. The number of characteristic bands defined were 10, 12, 12, 14 and 19 for l-alanine (strongest intensity band: 832 cm-1), l-aspartic acid (938 cm-1), l-cysteine (679 cm-1), l-glutamine (1090 cm-1) and glycine (875 cm-1), respectively. The intensity of bands differed by up to six times when several points on the crystal sample were rotated through 360 °; to reduce this effect when defining characteristic bands for other molecules, we find that spectra should be recorded at a statistically significant number of points per sample to remove the effect of sample rotation. It is crucial that sets of characteristic Raman bands are defined for biomarkers that are targets for future planetary missions to ensure a positive identification can be made.

  1. Defining Multiple Characteristic Raman Bands of α-Amino Acids as Biomarkers for Planetary Missions Using a Statistical Method.

    PubMed

    Rolfe, S M; Patel, M R; Gilmour, I; Olsson-Francis, K; Ringrose, T J

    2016-06-01

    Biomarker molecules, such as amino acids, are key to discovering whether life exists elsewhere in the Solar System. Raman spectroscopy, a technique capable of detecting biomarkers, will be on board future planetary missions including the ExoMars rover. Generally, the position of the strongest band in the spectra of amino acids is reported as the identifying band. However, for an unknown sample, it is desirable to define multiple characteristic bands for molecules to avoid any ambiguous identification. To date, there has been no definition of multiple characteristic bands for amino acids of interest to astrobiology. This study examined L-alanine, L-aspartic acid, L-cysteine, L-glutamine and glycine and defined several Raman bands per molecule for reference as characteristic identifiers. Per amino acid, 240 spectra were recorded and compared using established statistical tests including ANOVA. The number of characteristic bands defined were 10, 12, 12, 14 and 19 for L-alanine (strongest intensity band: 832 cm(-1)), L-aspartic acid (938 cm(-1)), L-cysteine (679 cm(-1)), L-glutamine (1090 cm(-1)) and glycine (875 cm(-1)), respectively. The intensity of bands differed by up to six times when several points on the crystal sample were rotated through 360 °; to reduce this effect when defining characteristic bands for other molecules, we find that spectra should be recorded at a statistically significant number of points per sample to remove the effect of sample rotation. It is crucial that sets of characteristic Raman bands are defined for biomarkers that are targets for future planetary missions to ensure a positive identification can be made. PMID:26744263

  2. Defining Multiple Characteristic Raman Bands of α-Amino Acids as Biomarkers for Planetary Missions Using a Statistical Method.

    PubMed

    Rolfe, S M; Patel, M R; Gilmour, I; Olsson-Francis, K; Ringrose, T J

    2016-06-01

    Biomarker molecules, such as amino acids, are key to discovering whether life exists elsewhere in the Solar System. Raman spectroscopy, a technique capable of detecting biomarkers, will be on board future planetary missions including the ExoMars rover. Generally, the position of the strongest band in the spectra of amino acids is reported as the identifying band. However, for an unknown sample, it is desirable to define multiple characteristic bands for molecules to avoid any ambiguous identification. To date, there has been no definition of multiple characteristic bands for amino acids of interest to astrobiology. This study examined L-alanine, L-aspartic acid, L-cysteine, L-glutamine and glycine and defined several Raman bands per molecule for reference as characteristic identifiers. Per amino acid, 240 spectra were recorded and compared using established statistical tests including ANOVA. The number of characteristic bands defined were 10, 12, 12, 14 and 19 for L-alanine (strongest intensity band: 832 cm(-1)), L-aspartic acid (938 cm(-1)), L-cysteine (679 cm(-1)), L-glutamine (1090 cm(-1)) and glycine (875 cm(-1)), respectively. The intensity of bands differed by up to six times when several points on the crystal sample were rotated through 360 °; to reduce this effect when defining characteristic bands for other molecules, we find that spectra should be recorded at a statistically significant number of points per sample to remove the effect of sample rotation. It is crucial that sets of characteristic Raman bands are defined for biomarkers that are targets for future planetary missions to ensure a positive identification can be made.

  3. Wireless Low-Power Integrated Basal-Body-Temperature Detection Systems Using Teeth Antennas in the MedRadio Band.

    PubMed

    Yang, Chin-Lung; Zheng, Gou-Tsun

    2015-01-01

    This study proposes using wireless low power thermal sensors for basal-body-temperature detection using frequency modulated telemetry devices. A long-term monitoring sensor requires low-power circuits including a sampling circuit and oscillator. Moreover, temperature compensated technologies are necessary because the modulated frequency might have additional frequency deviations caused by the varying temperature. The temperature compensated oscillator is composed of a ring oscillator and a controlled-steering current source with temperature compensation, so the output frequency of the oscillator does not drift with temperature variations. The chip is fabricated in a standard Taiwan Semiconductor Manufacturing Company (TSMC) 0.18-μm complementary metal oxide semiconductor (CMOS) process, and the chip area is 0.9 mm². The power consumption of the sampling amplifier is 128 µW. The power consumption of the voltage controlled oscillator (VCO) core is less than 40 µW, and the output is -3.04 dBm with a buffer stage. The output voltage of the bandgap reference circuit is 1 V. For temperature measurements, the maximum error is 0.18 °C with a standard deviation of ±0.061 °C, which is superior to the required specification of 0.1 °C. PMID:26610508

  4. Wireless Low-Power Integrated Basal-Body-Temperature Detection Systems Using Teeth Antennas in the MedRadio Band

    PubMed Central

    Yang, Chin-Lung; Zheng, Gou-Tsun

    2015-01-01

    This study proposes using wireless low power thermal sensors for basal-body-temperature detection using frequency modulated telemetry devices. A long-term monitoring sensor requires low-power circuits including a sampling circuit and oscillator. Moreover, temperature compensated technologies are necessary because the modulated frequency might have additional frequency deviations caused by the varying temperature. The temperature compensated oscillator is composed of a ring oscillator and a controlled-steering current source with temperature compensation, so the output frequency of the oscillator does not drift with temperature variations. The chip is fabricated in a standard Taiwan Semiconductor Manufacturing Company (TSMC) 0.18-μm complementary metal oxide semiconductor (CMOS) process, and the chip area is 0.9 mm2. The power consumption of the sampling amplifier is 128 µW. The power consumption of the voltage controlled oscillator (VCO) core is less than 40 µW, and the output is −3.04 dBm with a buffer stage. The output voltage of the bandgap reference circuit is 1 V. For temperature measurements, the maximum error is 0.18 °C with a standard deviation of ±0.061 °C, which is superior to the required specification of 0.1 °C. PMID:26610508

  5. Wireless Low-Power Integrated Basal-Body-Temperature Detection Systems Using Teeth Antennas in the MedRadio Band.

    PubMed

    Yang, Chin-Lung; Zheng, Gou-Tsun

    2015-11-20

    This study proposes using wireless low power thermal sensors for basal-body-temperature detection using frequency modulated telemetry devices. A long-term monitoring sensor requires low-power circuits including a sampling circuit and oscillator. Moreover, temperature compensated technologies are necessary because the modulated frequency might have additional frequency deviations caused by the varying temperature. The temperature compensated oscillator is composed of a ring oscillator and a controlled-steering current source with temperature compensation, so the output frequency of the oscillator does not drift with temperature variations. The chip is fabricated in a standard Taiwan Semiconductor Manufacturing Company (TSMC) 0.18-μm complementary metal oxide semiconductor (CMOS) process, and the chip area is 0.9 mm². The power consumption of the sampling amplifier is 128 µW. The power consumption of the voltage controlled oscillator (VCO) core is less than 40 µW, and the output is -3.04 dBm with a buffer stage. The output voltage of the bandgap reference circuit is 1 V. For temperature measurements, the maximum error is 0.18 °C with a standard deviation of ±0.061 °C, which is superior to the required specification of 0.1 °C.

  6. Design of pulse waveform for waveform division multiple access UWB wireless communication system.

    PubMed

    Yin, Zhendong; Wang, Zhirui; Liu, Xiaohui; Wu, Zhilu

    2014-01-01

    A new multiple access scheme, Waveform Division Multiple Access (WDMA) based on the orthogonal wavelet function, is presented. After studying the correlation properties of different categories of single wavelet functions, the one with the best correlation property will be chosen as the foundation for combined waveform. In the communication system, each user is assigned to different combined orthogonal waveform. Demonstrated by simulation, combined waveform is more suitable than single wavelet function to be a communication medium in WDMA system. Due to the excellent orthogonality, the bit error rate (BER) of multiuser with combined waveforms is so close to that of single user in a synchronous system. That is to say, the multiple access interference (MAI) is almost eliminated. Furthermore, even in an asynchronous system without multiuser detection after matched filters, the result is still pretty ideal and satisfactory by using the third combination mode that will be mentioned in the study.

  7. Distinct oligoclonal band antibodies in multiple sclerosis recognize ubiquitous self-proteins.

    PubMed

    Brändle, Simone M; Obermeier, Birgit; Senel, Makbule; Bruder, Jessica; Mentele, Reinhard; Khademi, Mohsen; Olsson, Tomas; Tumani, Hayrettin; Kristoferitsch, Wolfgang; Lottspeich, Friedrich; Wekerle, Hartmut; Hohlfeld, Reinhard; Dornmair, Klaus

    2016-07-12

    Oligoclonal Ig bands (OCBs) of the cerebrospinal fluid are a hallmark of multiple sclerosis (MS), a disabling inflammatory disease of the central nervous system (CNS). OCBs are locally produced by clonally expanded antigen-experienced B cells and therefore are believed to hold an important clue to the pathogenesis. However, their target antigens have remained unknown, mainly because it was thus far not possible to isolate distinct OCBs against a background of polyclonal antibodies. To overcome this obstacle, we copurified disulfide-linked Ig heavy and light chains from distinct OCBs for concurrent analysis by mass spectrometry and aligned patient-specific peptides to corresponding transcriptome databases. This method revealed the full-length sequences of matching chains from distinct OCBs, allowing for antigen searches using recombinant OCB antibodies. As validation, we demonstrate that an OCB antibody from a patient with an infectious CNS disorder, neuroborreliosis, recognized a Borrelia protein. Next, we produced six recombinant antibodies from four MS patients and identified three different autoantigens. All of them are conformational epitopes of ubiquitous intracellular proteins not specific to brain tissue. Our findings indicate that the B-cell response in MS is heterogeneous and partly directed against intracellular autoantigens released during tissue destruction. In addition to helping elucidate the role of B cells in MS, our approach allows the identification of target antigens of OCB antibodies in other neuroinflammatory diseases and the production of therapeutic antibodies in infectious CNS diseases. PMID:27325759

  8. Clinical and cognitive implications of cerebrospinal fluid oligoclonal bands in multiple sclerosis patients.

    PubMed

    Anagnostouli, Maria; Christidi, Foteini; Zalonis, Ioannis; Nikolaou, Chryssoula; Lyrakos, Dimitrios; Triantafyllou, Nikolaos; Evdokimidis, Ioannis; Kilidireas, Constantinos

    2015-11-01

    The presence of cerebrospinal fluid oligoclonal bands (CSF-OCB) in Caucasian patients with multiple sclerosis (MS) is supportive of diagnosis, though the relation with patients' clinical and specifically cognitive features has never been established or thoroughly examined. Thus, we investigated the clinical and for the first time the cognitive profile of MS patients in relation to CSF-OCB. We studied 108 patients with and without OCB and recorded demographic characteristics and detailed clinical data. A comprehensive neuropsychological battery covering different cognitive domains (attention/processing speed, memory, perception/constructions, reasoning, executive functions) was administered to MS patients and 142 demographically related healthy controls (HC). We did not find any significant differences between patients with and without OCB on demographic and clinical parameters (p > 0.05), including subtype and brain neuroimaging findings. Results revealed significantly higher cognitive scores in HC compared to both OCB subgroups, with more widespread cognitive changes in patients with OCB. Analysis between OCB subgroups showed significantly worse performance in patients with OCB on visual memory (Rey's complex figure test-recall; p = 0.006). Concluding, the presence of CSF-OCB in our MS patients tends to be related to more widespread cognitive changes, specifically worse visual memory. Future longitudinal studies in different populations are warranted to better clarify the clinical and cognitive characteristics related to CSF-OCB which could serve as early biomarker in disease monitoring. PMID:26130146

  9. Single-Aperture Multiple-Carrier Uplink Using a 20 Kilowatt X-Band Transmitter

    NASA Astrophysics Data System (ADS)

    Cornish, T.

    2000-10-01

    This article describes empirical testing that has been performed on a Deep Space Network 20 kW X-band (7.17 GHz) klystron amplifier. The purpose of these tests is to characterize the intermodulation performance to a level of detail and accuracy not presently provided by theoretical models [1,2]. The data set is sufficiently complete to allow for amplitude and frequency prediction of third-, fifth-, and seventh-order intermodulation products for two or three drive carriers of equal or unequal amplitude. The data can be used for frequency planning and frequency management in a situation where multiple command signals are radiated simultaneously from a single uplink aperture. Although the data have been gathered on a specific make and model of klystron tube (CPI VA876P), it should be extensible to any five-cavity klystron tube since the intermodulation performance is a function of the general tube topology and not subject to unit-to-unit manufacturing variation. An Excel spreadsheet has been assembled to test carrier-frequency combinations for interference. The spreadsheet takes into account uplink signal bandwidth, spacecraft receiver bandwidth, Doppler shift, and acquisition frequency sweeps.

  10. Apparatus and method supporting wireless access to multiple security layers in an industrial control and automation system or other system

    DOEpatents

    Chen, Yu-Gene T.

    2013-04-16

    A method includes receiving a message at a first wireless node. The first wireless node is associated with a first wired network, and the first wired network is associated with a first security layer. The method also includes transmitting the message over the first wired network when at least one destination of the message is located in the first security layer. The method further includes wirelessly transmitting the message for delivery to a second wireless node when at least one destination of the message is located in a second security layer. The second wireless node is associated with a second wired network, and the second wired network is associated with the second security layer. The first and second security layers may be associated with different security paradigms and/or different security domains. Also, the message could be associated with destinations in the first and second security layers.

  11. Multiple views of the October 2003 Cedar Fires captured by the High Performance Wireless Research and Education Network

    NASA Astrophysics Data System (ADS)

    Morikawa, E.; Nayak, A.; Vernon, F.; Braun, H.; Matthews, J.

    2004-12-01

    Late October 2003 brought devastating fires to the entire Southern California region. The NSF-funded High Performance Wireless Research and Education Network (HPWREN - http://hpwren.ucsd.edu/) cameras captured the development and progress of the Cedar fire in San Diego County. Cameras on Mt. Laguna, Mt. Woodson, Ramona Airport, and North Peak, recording one frame every 12 seconds, allowed for a time-lapse composite showing the fire's formation and progress from its beginnings on October 26th, to October 30th. The time-lapse camera footage depicts gushing smoke formations during the day, and bright orange walls of fire at night. The final video includes time synchronized views from multiple cameras, and an animated map highlighting the progress of the fire over time, and a directional indicator for each of the displaying cameras. The video is narrated by the California Department of Forestry and Fire Protection Fire Captain Ron Serabia (retd.) who was working then as a Air Tactical Group Supervisor with the aerial assault on the Cedar Fire Sunday October 26, 2004. The movie will be made available for download from the Scripps Institution of Oceanography Visualization Center Visual Objects library (supported by the OptIPuter project) at http://www.siovizcenter.ucsd.edu.

  12. Burst Packet Loss Concealment Using Multiple Codebooks and Comfort Noise for CELP-Type Speech Coders in Wireless Sensor Networks

    PubMed Central

    Park, Nam In; Kim, Hong Kook; Jung, Min A; Lee, Seong Ro; Choi, Seung Ho

    2011-01-01

    In this paper, a packet loss concealment (PLC) algorithm for CELP-type speech coders is proposed in order to improve the quality of decoded speech under burst packet loss conditions in a wireless sensor network. Conventional receiver-based PLC algorithms in the G.729 speech codec are usually based on speech correlation to reconstruct the decoded speech of lost frames by using parameter information obtained from the previous correctly received frames. However, this approach has difficulty in reconstructing voice onset signals since the parameters such as pitch, linear predictive coding coefficient, and adaptive/fixed codebooks of the previous frames are mostly related to silence frames. Thus, in order to reconstruct speech signals in the voice onset intervals, we propose a multiple codebook-based approach that includes a traditional adaptive codebook and a new random codebook composed of comfort noise. The proposed PLC algorithm is designed as a PLC algorithm for G.729 and its performance is then compared with that of the PLC algorithm currently employed in G.729 via a perceptual evaluation of speech quality, a waveform comparison, and a preference test under different random and burst packet loss conditions. It is shown from the experiments that the proposed PLC algorithm provides significantly better speech quality than the PLC algorithm employed in G.729 under all the test conditions. PMID:22163902

  13. Comparative studies on photonic band structures of diamond and hexagonal diamond using the multiple scattering method

    NASA Astrophysics Data System (ADS)

    Chen, Hui; Zhang, Weiyi; Wang, Zhenlin

    2004-02-01

    Photonic band structures are investigated for both diamond and hexagonal diamond crystals composed of dielectric spheres, and absolute photonic band gaps (PBGs) are found in both cases. In agreement with both Karathanos and Moroz's calculations, a large PBG occurs between the eighth and ninth bands in diamond crystal, but a PBG in hexagonal diamond crystal is found to occur between the sixteenth and seventeenth bands because of the doubling of dielectric spheres in the primitive cell. To explore the physical mechanism of how the photonic band gap might be broadened, we have compared the electric field distributions (|E|2) of the 'valence' and 'conduction' band edges. Results show that the field intensity for the 'conduction' band locates in the inner core of the sphere while that of the 'valence' band concentrates in the outer shell. With this motivation, double-layer spheres are designed to enhance the corresponding photonic band gaps; the PBG is increased by 35% for the diamond structure, and 14% for the hexagonal diamond structure.

  14. Molecular genotyping of human Ureaplasma species based on multiple-banded antigen (MBA) gene sequences.

    PubMed

    Kong, F; Ma, Z; James, G; Gordon, S; Gilbert, G L

    2000-09-01

    Ureaplasma urealyticum has been divided into 14 serovars. Recently, subdivision of U. urealyticum into two species has been proposed: U. parvum (previously U. urealyticum parvo biovar), comprising four serovars (1, 3, 6, 14) and U. urealyticum (previously U. urealyticum T-960 biovar), 10 serovars (2, 4, 5, 7-13). The multiple-banded antigen (MBA) genes of these species contain both species and serovar/subtype specific sequences. Based on whole sequences of the 5'-ends of MBA genes of U. parvum serovars and partial sequences of the 5'-ends of MBA genes of U. urealyticum serovars, we previously divided each of these species into three MBA genotypes. To further elucidate the relationships between serovars, we sequenced the whole 5'-ends of MBA genes of all 10 U. urealyticum serovars and partial repetitive regions of these genes from all serovars of U. parvum and U. urealyticum. For the first time, all four serovars of U. parvum were clearly differentiated from each other. In addition, the 10 serovars of U. urealyticum were divided into five MBA genotypes, as follows: MBA genotype A comprises serovars 2, 5, 8; MBA genotype B, serovar 10 only; MBA genotype C, serovars 4, 12, 13; MBA genotype D, serovar 9 only; and MBA genotype E comprises serovars 7 and 11. There were no sequence differences between members within each MBA genotype. Further work is required to identify other genes or other regions of the MBA genes that may be used to differentiate U. urealyticum serovars within MBA genotypes A, C and E. A better understanding of the molecular basis of serotype differentiation will help to improve subtyping methods for use in studies of the pathogenesis and epidemiology of these organisms.

  15. Development of an X-Band 50 MW Multiple Beam Klystron

    NASA Astrophysics Data System (ADS)

    Song, Liqun; Ferguson, Patrick; Ives, R. Lawrence; Miram, George; Marsden, David; Mizuhara, Max

    2003-12-01

    Calabazas Creek Research, Inc. is developing an X-band 50 MW multiple beam klystron (MBK) on a DOE SBIR Phase II grant. The electrical design and preliminary mechanical design were completed on the Phase I. This MBK consists of eight discrete klystron circuits driven by eight electron beams located symmetrically on a circle with a radius of 6.3 cm. Each beam operates at 190 kV and 66 A. The eight beam electron gun is in development on a DOE SBIR Phase II grant. Each circuit consists of an input cavity, two gain cavities, three penultimate cavities, and a three cavity output circuit operating in the PI/2 mode. Ring resonators were initially proposed for the complete circuit; however, low beam — wave interaction resulted in the necessity to use discrete cavities for all eight circuits. The input cavities are coupled via hybrid waveguides to ensure constant drive power amplitude and phase. The output circuits can either be combined using compact waveguide twists driving a TE01 high power window or combined into a TM04 mode converter driving the same TE01 window. The gain and efficiency for a single circuit has been optimized using KLSC, a 2 1/2D large signal klystron code. Simulations for a single circuit predict an efficiency of 53% for a single output cavity and 55% for the three cavity output resonator. The total RF output power for this MBK is 55 MW. During the Phase II emphasis will be given to cost reduction techniques resulting in a robust — high efficient — long life high power amplifier.

  16. Band width and multiple-angle valence-state mapping of diamond

    SciTech Connect

    Jimenez, I.; Terminello, L.J.; Sutherland, D.G.J.

    1997-04-01

    The band width may be considered the single most important parameter characterizing the electronic structure of a solid. The ratio of band width and Coulomb repulsion determines how correlated or delocalized an electron system is. Some of the most interesting solids straddle the boundary between localized and delocalized, e.g. the high-temperature superconductors. The bulk of the band calculations available today is based on local density functional (DF) theory. Even though the Kohn-Sham eigenvalues from that theory do not represent the outcome of a band-mapping experiment, they are remarkably similar to the bands mapped via photoemission. Strictly speaking, one should use an excited state calculation that takes the solid`s many-body screening response to the hole created in photoemission into account. Diamond is a useful prototype semiconductor because of its low atomic number and large band width, which has made it a long-time favorite for testing band theory. Yet, the two experimental values of the band width of diamond have error bars of {+-}1 eV and differ by 3.2 eV. To obtain an accurate valence band width for diamond, the authors use a band-mapping method that collects momentum distributions instead of the usual energy distributions. This method has undergone extensive experimental and theoretical tests in determining the band width of lithium fluoride. An efficient, imaging photoelectron spectrometer is coupled with a state-of-the-art undulator beam line at the Advanced Light Source to allow collection of a large number of data sets. Since it takes only a few seconds to take a picture of the photoelectrons emitted into a 84{degrees} cone, the authors can use photon energies as high as 350 eV where the cross section for photoemission from the valence band is already quite low, but the emitted photoelectrons behave free-electron-like. This make its much easier to locate the origin of the inter-band transitions in momentum space.

  17. On Deployment of Multiple Base Stations for Energy-Efficient Communication in Wireless Sensor Networks

    DOE PAGESBeta

    Lin, Yunyue; Wu, Qishi; Cai, Xiaoshan; Du, Xiaojiang; Kwon, Ki-Hyeon

    2010-01-01

    Data transmission from sensor nodes to a base station or a sink node often incurs significant energy consumption, which critically affects network lifetime. We generalize and solve the problem of deploying multiple base stations to maximize network lifetime in terms of two different metrics under one-hop and multihop communication models. In the one-hop communication model, the sensors far away from base stations always deplete their energy much faster than others. We propose an optimal solution and a heuristic approach based on the minimal enclosing circle algorithm to deploy a base station at the geometric center of each cluster. In themore » multihop communication model, both base station location and data routing mechanism need to be considered in maximizing network lifetime. We propose an iterative algorithm based on rigorous mathematical derivations and use linear programming to compute the optimal routing paths for data transmission. Simulation results show the distinguished performance of the proposed deployment algorithms in maximizing network lifetime.« less

  18. Simultaneous fat suppression and band reduction with large-angle multiple-acquisition balanced steady-state free precession.

    PubMed

    Quist, Brady; Hargreaves, Brian A; Cukur, Tolga; Morrell, Glen R; Gold, Garry E; Bangerter, Neal K

    2012-04-01

    Balanced steady-state free precession (bSSFP) MRI is a rapid and signal-to-noise ratio-efficient imaging method, but suffers from characteristic bands of signal loss in regions of large field inhomogeneity. Several methods have been developed to reduce the severity of these banding artifacts, typically involving the acquisition of multiple bSSFP datasets (and the accompanying increase in scan time). Fat suppression with bSSFP is also challenging; most existing methods require an additional increase in scan time, and some are incompatible with bSSFP band-reduction techniques. This work was motivated by the need for both robust fat suppression and band reduction in the presence of field inhomogeneity when using bSSFP for flow-independent peripheral angiography. The large flip angles used in this application to improve vessel conspicuity and contrast lead to specific absorption rate considerations, longer repetition times, and increased severity of banding artifacts. In this work, a novel method that simultaneously suppresses fat and reduces bSSFP banding artifact with the acquisition of only two phase-cycled bSSFP datasets is presented. A weighted sum of the two bSSFP acquisitions is taken on a voxel-by-voxel basis, effectively synthesizing an off-resonance profile at each voxel that puts fat in the stop band while keeping water in the pass band. The technique exploits the near-sinusoidal shape of the bSSFP off-resonance spectrum for many tissues at large (>50°) flip angles.

  19. Wireless indoor millimeter-wave beamforming array

    NASA Astrophysics Data System (ADS)

    Tao, Y. M.; Delisle, G. Y.

    1998-11-01

    A practical design of a compact integrated Rotman lens is presented, which will be used as a beamformer of multiple beam antenna arrays in wireless indoor communication network. An improved design equations of integrated Rotman lens is derived to calculate the lens contour and a non-circular focal arc is introduced in beam ports to minimize the phase aberrations on the aperture of array. A log-periodic electromagnetic coupling microstrip patch array is adopted as radiation elements. Both theoretical and experimental results show the designed multiple beam antenna has wide band width performance.

  20. On using multiple routing metrics with destination sequenced distance vector protocol for MultiHop wireless ad hoc networks

    NASA Astrophysics Data System (ADS)

    Mehic, M.; Fazio, P.; Voznak, M.; Partila, P.; Komosny, D.; Tovarek, J.; Chmelikova, Z.

    2016-05-01

    A mobile ad hoc network is a collection of mobile nodes which communicate without a fixed backbone or centralized infrastructure. Due to the frequent mobility of nodes, routes connecting two distant nodes may change. Therefore, it is not possible to establish a priori fixed paths for message delivery through the network. Because of its importance, routing is the most studied problem in mobile ad hoc networks. In addition, if the Quality of Service (QoS) is demanded, one must guarantee the QoS not only over a single hop but over an entire wireless multi-hop path which may not be a trivial task. In turns, this requires the propagation of QoS information within the network. The key to the support of QoS reporting is QoS routing, which provides path QoS information at each source. To support QoS for real-time traffic one needs to know not only minimum delay on the path to the destination but also the bandwidth available on it. Therefore, throughput, end-to-end delay, and routing overhead are traditional performance metrics used to evaluate the performance of routing protocol. To obtain additional information about the link, most of quality-link metrics are based on calculation of the lost probabilities of links by broadcasting probe packets. In this paper, we address the problem of including multiple routing metrics in existing routing packets that are broadcasted through the network. We evaluate the efficiency of such approach with modified version of DSDV routing protocols in ns-3 simulator.

  1. Multichannel neural recording with a 128 Mbps UWB wireless transmitter for implantable brain-machine interfaces.

    PubMed

    Ando, H; Takizawa, K; Yoshida, T; Matsushita, K; Hirata, M; Suzuki, T

    2015-01-01

    To realize a low-invasive and high accuracy BMI (Brain-machine interface) system, we have already developed a fully-implantable wireless BMI system which consists of ECoG neural electrode arrays, neural recording ASICs, a Wi-Fi based wireless data transmitter and a wireless power receiver with a rechargeable battery. For accurate estimation of movement intentions, it is important for a BMI system to have a large number of recording channels. In this paper, we report a new multi-channel BMI system which is able to record up to 4096-ch ECoG data by multiple connections of 64-ch ASICs and time division multiplexing of recorded data. This system has an ultra-wide-band (UWB) wireless unit for transmitting the recorded neural signals to outside the body. By preliminary experiments with a human body equivalent liquid phantom, we confirmed 4096-ch UWB wireless data transmission at 128 Mbps mode below 20 mm distance.

  2. Lipid arrays identify myelin-derived lipids and lipid complexes as prominent targets for oligoclonal band antibodies in multiple sclerosis

    PubMed Central

    Brennan, Kathryn M.; Galban-Horcajo, Francesc; Rinaldi, Simon; O'Leary, Colin P.; Goodyear, Carl S.; Kalna, Gabriela; Arthur, Ariel; Elliot, Christina; Barnett, Sue; Linington, Christopher; Bennett, Jeffrey L.; Owens, Gregory P.; Willison, Hugh J.

    2012-01-01

    The presence of oligoclonal bands of IgG (OCB) in cerebrospinal fluid (CSF) is used to establish a diagnosis of multiple sclerosis (MS), but their specificity has remained an enigma since its first description over forty years ago. We now report that the use of lipid arrays identifies heteromeric complexes of myelin derived lipids as a prominent target for this intrathecal B cell response. PMID:21872346

  3. A wireless vibrating wire sensor node for continuous structural health monitoring

    NASA Astrophysics Data System (ADS)

    Lee, H. M.; Kim, J. M.; Sho, K.; Park, H. S.

    2010-05-01

    Vibrating wire sensors (VWS) are generally used for strain measurements of structures in buildings and civil infrastructures. In this paper, a wireless vibrating wire sensor node is developed which can measure resonance frequencies from vibrating wire sensors and can remotely communicate the frequencies by wireless. The wireless sensor node consists of a sensor module, which excites the vibrating wire and reads the resonance frequencies, a wireless communication module, which transmits the wire's resonance frequencies to the user or administrator, and a processor that controls the two modules. The wireless sensor node has the following characteristics: it has multiple channels to enable measurement of multiple vibrating wire sensors (up to four) using a single sensor node; it has a power-saving feature that enables operation for up to one year; and lastly, the wireless unit uses the 424 MHz UHF (ultra-high frequency) band with good diffraction that has an effect on minimizing the influence of impediments such as structural or nonstructural elements. The wireless sensor node is tested in terms of its measurement precision and its wireless communication performance. As a result, it is confirmed that the node enables the long-term structural health monitoring of buildings and infrastructures.

  4. Multiple-Scale Pattern Recognition Applied to Faint Intergranular G-band Structures

    NASA Astrophysics Data System (ADS)

    Bovelet, B.; Wiehr, E.

    2007-07-01

    Small-scale solar magnetic flux concentrations are studied in two-dimensional G-band images at very high spatial resolution and compared with Ca ii H enhancements. Among 970 small-sized G-band intergranular structures (IgS), 45% are co-spatial with isolated locations of Ca ii H excess and thus considered as magnetic (MIgS); they may be even twice as frequent as the known G-band bright points. The IgS are recognized in the G-band image by a new algorithm operating in four steps: (1) A set of equidistant detection levels yields a pattern of primary “cells”; (2) for each cell, the intrinsic intensity profile is normalized to its brightest pixel; (3) the cell sizes are shrunk by a unitary single-intensity clip; (4) features in contact at an appropriate reference level are merged by removal of the respective common dividing lines. Optionally, adjoining structures may be excluded from this merging process ( e.g., chains of segmented IgS), referring to the parameterized number and intensity of those pixels where enveloping feature contours overlap. From the thus recognized IgS pattern, MIgS are then selected by their local Ca ii H contrast and their mean G-band-to-continuum brightness ratio.

  5. Construction of a wireless communication contact closure system for liquid chromatography with multiple parallel mass spectrometers and other detectors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A contact closure system has been constructed and implemented that utilizes two contact closure sender boards that communicate wirelessly to four contact closure receiver boards to distribute start signals from two or three liquid chromatographs to fourteen instruments, pumps, detectors, or other co...

  6. Using multiple-polarization L-band radar to monitor marsh burn recovery

    USGS Publications Warehouse

    Ramsey, Elijah W., III; Nelson, G.A.; Sapkota, S.K.; Laine, S.C.; Verdi, J.; Rrasznay, S.

    1999-01-01

    Aircraft L-band VV-, HH-, and VH-polarizations were examined as tools for monitoring burn recovery in a coastal marsh. Significant relationships were observed between time-since-burn (difference between burn and image collection dates; 550-900 days after burn) and returns related to all polarizations. As marsh burn recovery progressed, VV returns decreased while HH and VH returns increased. Radar returns extracted from control sites adjacent to each burn-simulated nonburn marsh and were not individually or in combination significantly related to the timesince-burn. Normalized by the control data, VH-polarization explained up to 83% of the total variations. Overall, the L-band multipolarization radars estimated time-since-burn within ??59 to ??92 days. ?? 1999 IEEE.

  7. Skin hydration by spectroscopic imaging using multiple near-infrared bands

    NASA Astrophysics Data System (ADS)

    Attas, E. Michael; Sowa, Michael G.; Posthumus, Trevor B.; Schattka, Bernhard J.; Mantsch, Henry H.; Zhang, Shuliang L.

    2002-03-01

    Near-infrared spectroscopic methods have been developed to determine the degree of hydration of human skin in vivo. Reflectance spectroscopic imaging was used to investigate the distribution of skin moisture as a function of location. A human study in a clinical setting has generated quantitative data showing the effects of a drying agent and a moisturizer on delineated regions of the forearms of eight volunteers. Two digital imaging systems equipped with liquid-crystal tunable filters were used to collect stacks of monochromatic images at 10-nm intervals over the wavelength bands 650-1050 nm and 960-1700 nm. Images generated from measurements of water absorption-band areas at three different near-IR wavelengths (970, 1200, and 1450 nm) showed obvious differences in the apparent distribution of water in skin. Changes resulting from the skin treatments were much more evident in the 1200-nm and 1450-nm images than in the 970-nm ones. The variable sensitivity of the method at different wavelengths has been interpreted as being the result of different penetration depths of the infrared light used in the reflectance studies. Ex-vivo experiments with pigskin have provided evidence supporting the relationship between wavelength and penetration depth. Combining the hydration results from several near-IR water bands allows additional information on hydration depth to be obtained.

  8. Polarization-independent dual-band perfect absorber utilizing multiple magnetic resonances.

    PubMed

    Yoo, Young Joon; Kim, Young Joo; Van Tuong, Pham; Rhee, Joo Yull; Kim, Ki Won; Jang, Won Ho; Kim, Y H; Cheong, H; Lee, Youngpak

    2013-12-30

    We propose a dual-band metamaterial perfect absorber at microwave frequencies. Using a planar metamaterial, which consists of periodic metallic donut-shape meta-atoms at the front separated from the metallic plane at the back by a dielectric layer, we demonstrate the multi-plasmonic high-frequency perfect absorptions induced by the third-harmonic as well as the fundamental magnetic resonances. The origin of the induced multi-plasmonic perfect absorption was elucidated. It was also found that the perfect absorptions at dual peaks are persistent with varying polarization.

  9. A satellite mobile communication system based on Band-Limited Quasi-Synchronous Code Division Multiple Access (BLQS-CDMA)

    NASA Technical Reports Server (NTRS)

    Degaudenzi, R.; Elia, C.; Viola, R.

    1990-01-01

    Discussed here is a new approach to code division multiple access applied to a mobile system for voice (and data) services based on Band Limited Quasi Synchronous Code Division Multiple Access (BLQS-CDMA). The system requires users to be chip synchronized to reduce the contribution of self-interference and to make use of voice activation in order to increase the satellite power efficiency. In order to achieve spectral efficiency, Nyquist chip pulse shaping is used with no detection performance impairment. The synchronization problems are solved in the forward link by distributing a master code, whereas carrier forced activation and closed loop control techniques have been adopted in the return link. System performance sensitivity to nonlinear amplification and timing/frequency synchronization errors are analyzed.

  10. Faster than fiber: over 100-Gb/s signal delivery in fiber wireless integration system.

    PubMed

    Yu, Jianjun; Li, Xinying; Chi, Nan

    2013-09-23

    We summarize several different approaches for the realization of large capacity (>100Gb/s) fiber wireless integration system, including optical polarization-division-multiplexing (PDM) combined with multiple-input multiple-output (MIMO) reception, advanced multi-level modulation, optical multi-carrier modulation, electrical multi-carrier modulation, antenna polarization multiplexing and multi-band multiplexing. These approaches can effectively reduce the signal baud rate as well as the required bandwidth for optical and electrical devices. We also investigate the problems, such as wireless multi-path effect due to different wireless transmission distance, existing in the large capacity fiber wireless integration system. We demonstrate these problems can be effectively solved based on advanced digital-signal-processing (DSP) algorithms including classic constant modulus algorithm (CMA). Moreover, based on the combination of these approaches as well as advanced DSP algorithms, we have successfully demonstrated a 400G fiber wireless integration system, which creates a capacity record of wireless delivery and ushers in a new era of ultra-high bit rate (>400Gb/s) optical wireless integration communications at mm-wave frequencies.

  11. Wireless hippocampal neural recording via a multiple input RF receiver to construct place-specific firing fields.

    PubMed

    Lee, Seung Bae; Manns, Joseph R; Ghovanloo, Maysam

    2012-01-01

    This paper reports scientifically meaningful in vivo experiments using a 32-channel wireless neural recording system (WINeR). The WINeR system is divided into transmitter (Tx) and receiver (Rx) parts. On the Tx side, we had WINeR-6, a system-on-a-chip (SoC) that operated based on time division multiplexing (TDM) of pulse width modulated (PWM) samples. The chip was fabricated in a 0.5-µm CMOS process, occupying 4.9 × 3.3 mm(2) and consuming 15 mW from ±1.5V supplies. The Rx used two antennas with separate pathways to down-convert the RF signal from a large area. A time-to-digital converter (TDC) in an FPGA converted the PWM pulses into digitized samples. In order to further increase the wireless coverage area and eliminate blind spots within a large experimental arena, two receivers were synchronized. The WINeR system was used to record epileptic activities from a rat that was injected with tetanus toxin (TT) in the dorsal hippocampus. In a different in vivo experiment, place-specific firing fields of place cells, which are parts of the hippocampal-dependent memory, were mapped from a series of behavioral experiments from a rat running in a circular track. Results from the same animal were compared against a commercial hard-wired recording system to evaluate the quality of the wireless recordings.

  12. Planar UWB Filter with Multiple Notched Band and Stopband with Improved Rejection Level

    NASA Astrophysics Data System (ADS)

    Ghazali, Abu Nasar; Pal, Srikanta

    2015-05-01

    Analysis and realization of a microstrip-based planar ultra-wideband (UWB) filter with integrated multiple notch elimination property and simultaneously extended upper stopband is proposed. Initially, a UWB filter based on back-to-back microstrip-to-CPW technology is designed. Later, multiple spiral defected ground structures (DGS) are embedded to obtain multiple passband notches. Further, double equilateral U (DEU)-type DGS are used to improve upon the rejection level in upper stopband. The multiple passband notches are results of embedded spiral-shaped DGS (SDGS), while extended upper stopband is the outcome of suppressed higher-order spurious harmonics. The flexible dual-attenuation poles of DEU-shaped DGS suppress the stopband harmonics and widen the stopband. An approximate lumped equivalent circuit model of the proposed filter is modelled. The filter is compact and its layout measures 25.26 mm × 11.01 mm. The measured result is in good agreement with the full-wave electromagnetic (EM) simulation and circuit simulation.

  13. Wireless Technologies in Support of ISS Experimentation and Operations

    NASA Technical Reports Server (NTRS)

    Wagner, Raymond; Fink, Patrick

    2012-01-01

    Presentation reviews: (1) Wireless Communications (a) Internal (b) External (2) RFID (Radio Frequency Identification) (a) Existing and R&D (3) Wireless Sensor Networks (a) Existing and R&D (4) Ultra-Wide Band (UWB) (a) R&D

  14. Spectroscopic determination of leaf biochemistry using band-depth analysis of absorption features and stepwise multiple linear regression

    USGS Publications Warehouse

    Kokaly, R.F.; Clark, R.N.

    1999-01-01

    We develop a new method for estimating the biochemistry of plant material using spectroscopy. Normalized band depths calculated from the continuum-removed reflectance spectra of dried and ground leaves were used to estimate their concentrations of nitrogen, lignin, and cellulose. Stepwise multiple linear regression was used to select wavelengths in the broad absorption features centered at 1.73 ??m, 2.10 ??m, and 2.30 ??m that were highly correlated with the chemistry of samples from eastern U.S. forests. Band depths of absorption features at these wavelengths were found to also be highly correlated with the chemistry of four other sites. A subset of data from the eastern U.S. forest sites was used to derive linear equations that were applied to the remaining data to successfully estimate their nitrogen, lignin, and cellulose concentrations. Correlations were highest for nitrogen (R2 from 0.75 to 0.94). The consistent results indicate the possibility of establishing a single equation capable of estimating the chemical concentrations in a wide variety of species from the reflectance spectra of dried leaves. The extension of this method to remote sensing was investigated. The effects of leaf water content, sensor signal-to-noise and bandpass, atmospheric effects, and background soil exposure were examined. Leaf water was found to be the greatest challenge to extending this empirical method to the analysis of fresh whole leaves and complete vegetation canopies. The influence of leaf water on reflectance spectra must be removed to within 10%. Other effects were reduced by continuum removal and normalization of band depths. If the effects of leaf water can be compensated for, it might be possible to extend this method to remote sensing data acquired by imaging spectrometers to give estimates of nitrogen, lignin, and cellulose concentrations over large areas for use in ecosystem studies.We develop a new method for estimating the biochemistry of plant material using

  15. Multiple sclerosis patients lacking oligoclonal bands in the cerebrospinal fluid have less global and regional brain atrophy.

    PubMed

    Ferreira, Daniel; Voevodskaya, Olga; Imrell, Kerstin; Stawiarz, Leszek; Spulber, Gabriela; Wahlund, Lars-Olof; Hillert, Jan; Westman, Eric; Karrenbauer, Virginija Danylaité

    2014-09-15

    To investigate whether multiple sclerosis (MS) patients with and without cerebrospinal fluid (CSF) oligoclonal immunoglobulin G bands (OCB) differ in brain atrophy. Twenty-eight OCB-negative and thirty-five OCB-positive patients were included. Larger volumes of total CSF and white matter (WM) lesions; smaller gray matter (GM) volume in the basal ganglia, diencephalon, cerebellum, and hippocampus; and smaller WM volume in corpus callosum, periventricular-deep WM, brainstem, and cerebellum, were observed in OCB-positives. OCB-negative patients, known to differ genetically from OCB-positives, are characterized by less global and regional brain atrophy. This finding supports the notion that OCB-negative MS patients may represent a clinically relevant MS subgroup. PMID:24999245

  16. Superfluid Density and Flux-Flow Resistivity Measurements of Multiple-Band Superconductor β-PdBi2

    NASA Astrophysics Data System (ADS)

    Okada, Tatsunori; Imai, Yoshinori; Maeda, Atsutaka

    β -PdBi2 (Tcmax = 5 . 4 K) is a newcomer of the multiple-band superconductors, revealed by the specific heat and the upper critical field measurements, and the angle-resolved photoemission spectroscopy. In addition, authors of ref. observed the spin-polarized band dispersion and proposed that β-PdBi2 is a candidate of topological superconductor. However, there is less information on superconducting properties so far. In order to clarify the superconducting gap function, we measured the temperature (T) and magnetic field (B) dependence of microwave complex conductivity of β-PdBi2 single crystals. We found that the superfluid density exhibits the thermally activated T dependence, manifesting the absence of nodes in the superconducting gaps. We also found that the flux-flow resistivity increased with B with downward-convex shape. Based on some theories, we considered that such a behavior originated from the backflow of supercurrents around vortices reflecting rather small Ginzburg-Landau parameter (κ ~= 5). This work was supported by the JSPS KAKENHI (Grant Numbers 15K17697 and 26-9315), and the JSPS Research Fellowship for Young Scientists.

  17. An orthogonal wavelet division multiple-access processor architecture for LTE-advanced wireless/radio-over-fiber systems over heterogeneous networks

    NASA Astrophysics Data System (ADS)

    Mahapatra, Chinmaya; Leung, Victor CM; Stouraitis, Thanos

    2014-12-01

    The increase in internet traffic, number of users, and availability of mobile devices poses a challenge to wireless technologies. In long-term evolution (LTE) advanced system, heterogeneous networks (HetNet) using centralized coordinated multipoint (CoMP) transmitting radio over optical fibers (LTE A-ROF) have provided a feasible way of satisfying user demands. In this paper, an orthogonal wavelet division multiple-access (OWDMA) processor architecture is proposed, which is shown to be better suited to LTE advanced systems as compared to orthogonal frequency division multiple access (OFDMA) as in LTE systems 3GPP rel.8 (3GPP, http://www.3gpp.org/DynaReport/36300.htm). ROF systems are a viable alternative to satisfy large data demands; hence, the performance in ROF systems is also evaluated. To validate the architecture, the circuit is designed and synthesized on a Xilinx vertex-6 field-programmable gate array (FPGA). The synthesis results show that the circuit performs with a clock period as short as 7.036 ns (i.e., a maximum clock frequency of 142.13 MHz) for transform size of 512. A pipelined version of the architecture reduces the power consumption by approximately 89%. We compare our architecture with similar available architectures for resource utilization and timing and provide performance comparison with OFDMA systems for various quality metrics of communication systems. The OWDMA architecture is found to perform better than OFDMA for bit error rate (BER) performance versus signal-to-noise ratio (SNR) in wireless channel as well as ROF media. It also gives higher throughput and mitigates the bad effect of peak-to-average-power ratio (PAPR).

  18. Terabit Wireless Communication Challenges

    NASA Technical Reports Server (NTRS)

    Hwu, Shian U.

    2012-01-01

    This presentation briefly discusses a research effort on Terabit Wireless communication systems for possible space applications. Recently, terahertz (THz) technology (300-3000 GHz frequency) has attracted a great deal of interest from academia and industry. This is due to a number of interesting features of THz waves, including the nearly unlimited bandwidths available, and the non-ionizing radiation nature which does not damage human tissues and DNA with minimum health threat. Also, as millimeter-wave communication systems mature, the focus of research is, naturally, moving to the THz range. Many scientists regard THz as the last great frontier of the electromagnetic spectrum, but finding new applications outside the traditional niches of radio astronomy, Earth and planetary remote sensing, and molecular spectroscopy particularly in biomedical imaging and wireless communications has been relatively slow. Radiologists find this area of study so attractive because t-rays are non-ionizing, which suggests no harm is done to tissue or DNA. They also offer the possibility of performing spectroscopic measurements over a very wide frequency range, and can even capture signatures from liquids and solids. According to Shannon theory, the broad bandwidth of the THz frequency bands can be used for terabit-per-second (Tb/s) wireless communication systems. This enables several new applications, such as cell phones with 360 degrees autostereoscopic displays, optic-fiber replacement, and wireless Tb/s file transferring. Although THz technology could satisfy the demand for an extremely high data rate, a number of technical challenges need to be overcome before its development. This presentation provides an overview the state-of-the- art in THz wireless communication and the technical challenges for an emerging application in Terabit wireless systems. The main issue for THz wave propagation is the high atmospheric attenuation, which is dominated by water vapor absorption in the THz

  19. 78 FR 48621 - Service Rules for Advanced Wireless Services in the 2000-2020 MHz and 2180-2200 MHz Bands, etc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-09

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS... 2180-2200 MHz Bands, etc. AGENCY: Federal Communications Commission. ACTION: Final rule; announcement of effective date. SUMMARY: In this document, the Commission announces that the Office of...

  20. Portable Integrated Wireless Device Threat Assessment to Aircraft Radio Systems

    NASA Technical Reports Server (NTRS)

    Salud, Maria Theresa P.; Williams, Reuben A. (Technical Monitor)

    2004-01-01

    An assessment was conducted on multiple wireless local area network (WLAN) devices using the three wireless standards for spurious radiated emissions to determine their threat to aircraft radio navigation systems. The measurement process, data and analysis are provided for devices tested using IEEE 802.11a, IEEE 802.11b, and Bluetooth as well as data from portable laptops/tablet PCs and PDAs (grouping known as PEDs). A comparison was made between wireless LAN devices and portable electronic devices. Spurious radiated emissions were investigated in the radio frequency bands for the following aircraft systems: Instrument Landing System Localizer and Glideslope, Very High Frequency (VHF) Communication, VHF Omnidirectional Range, Traffic Collision Avoidance System, Air Traffic Control Radar Beacon System, Microwave Landing System and Global Positioning System. Since several of the contiguous navigation systems were grouped under one encompassing measurement frequency band, there were five measurement frequency bands where spurious radiated emissions data were collected for the PEDs and WLAN devices. The report also provides a comparison between emissions data and regulatory emission limit.

  1. Detection of intrathecal immunoglobulin G synthesis by capillary isoelectric focusing immunoassay in oligoclonal band negative multiple sclerosis.

    PubMed

    Halbgebauer, Steffen; Huss, André; Buttmann, Mathias; Steinacker, Petra; Oeckl, Patrick; Brecht, Isabel; Weishaupt, Andreas; Tumani, Hayrettin; Otto, Markus

    2016-05-01

    Oligoclonal immunoglobulin G bands (OCBs) restricted to the cerebrospinal fluid indicate intrathecal inflammation. Using isoelectric focusing and immunoblotting, they are detected in about 95 % of patients with clinically definite multiple sclerosis (MS). To elucidate whether in the remaining 5 % OCBs are truly absent or alternatively missed due to insufficient sensitivity of the routine measurement, we employed a new, highly sensitive nanoscale method for OCB detection. Capillary isoelectric focusing followed by immunological detection served to analyze OCBs in 33 well-characterized OCB-negative and 10 OCB-positive MS patients as well as in 100 OCB-negative control patients with non-inflammatory neurological diseases and 30 OCB-positive control patients with inflammatory neurological diseases. We detected intrathecal immunoglobulin G production in 10 out of 33 MS patients (30 %), initially diagnosed as being OCB-negative, and in all 10 OCB-positive MS patients, but in only 3 out of 100 non-inflammatory neurological controls (3 %) and in 29 of 30 inflammatory neurological controls (97 %). At least about one-third of MS patients without intrathecal immunoglobulin G synthesis according to standard methods are OCB-positive. Advanced methods for OCB detection may increase the analytical sensitivity for detecting OCB in patients with MS who are OCB-negative according to current routine methods.

  2. Views of wireless network systems.

    SciTech Connect

    Young, William Frederick; Duggan, David Patrick

    2003-10-01

    Wireless networking is becoming a common element of industrial, corporate, and home networks. Commercial wireless network systems have become reliable, while the cost of these solutions has become more affordable than equivalent wired network solutions. The security risks of wireless systems are higher than wired and have not been studied in depth. This report starts to bring together information on wireless architectures and their connection to wired networks. We detail information contained on the many different views of a wireless network system. The method of using multiple views of a system to assist in the determination of vulnerabilities comes from the Information Design Assurance Red Team (IDART{trademark}) Methodology of system analysis developed at Sandia National Laboratories.

  3. A first generation cytogenetic ideogram for the Florida manatee (Trichechus manatus latirostris) based on multiple chromosome banding techniques

    USGS Publications Warehouse

    Gray, B.A.; Zori, Roberto T.; McGuire, P.M.; Bonde, R.K.

    2002-01-01

    Detailed chromosome studies were conducted for the Florida manatee (Trichechus manatus latirostris) utilizing primary chromosome banding techniques (G- and Q-banding). Digital microscopic imaging methods were employed and a standard G-banded karyotype was constructed for both sexes. Based on chromosome banding patterns and measurements obtained in these studies, a standard karyotype and ideogram are proposed. Characterization of additional cytogenetic features of this species by supplemental chromosome banding techniques, C-banding (constitutive heterochromatin), Ag-NOR staining (nucleolar organizer regions), and DA/DAPI staining, was also performed. These studies provide detailed cytogenetic data for T. manatus latirostris, which could enhance future genetic mapping projects and interspecific and intraspecific genomic comparisons by techniques such as zoo-FISH.

  4. Full band Monte Carlo modeling of impact ionization, avalanche multiplication, and noise in submicron GaAs p+-i-n+ diodes

    NASA Astrophysics Data System (ADS)

    Ong, D. S.; Li, K. F.; Plimmer, S. A.; Rees, G. J.; David, J. P. R.; Robson, P. N.

    2000-06-01

    A full-band Monte Carlo model is used to investigate the probability distribution functions of impact ionization path length and impact ionization energy for electrons and holes in GaAs. The simulations show that the soft ionization threshold energy in GaAs allows impact ionization to occur at energies much higher than the band gap. As a result, secondary carriers have a shorter dead space than newly injected carriers. The ionization path length distributions narrow at higher fields, producing a more deterministic impact ionization process in thin devices. The model is also used to simulate avalanche multiplication and noise in submicron homojunction GaAs p+-i-n+ diodes. The predicted mean multiplication, and excess noise factor, F are in quantitative agreement with the experimental results, in which F decreases as the length of multiplication region is reduced.

  5. Behavioral modeling and digital compensation of nonlinearity in DFB lasers for multi-band directly modulated radio-over-fiber systems

    NASA Astrophysics Data System (ADS)

    Li, Jianqiang; Yin, Chunjing; Chen, Hao; Yin, Feifei; Dai, Yitang; Xu, Kun

    2014-11-01

    The envisioned C-RAN concept in wireless communication sector replies on distributed antenna systems (DAS) which consist of a central unit (CU), multiple remote antenna units (RAUs) and the fronthaul links between them. As the legacy and emerging wireless communication standards will coexist for a long time, the fronthaul links are preferred to carry multi-band multi-standard wireless signals. Directly-modulated radio-over-fiber (ROF) links can serve as a lowcost option to make fronthaul connections conveying multi-band wireless signals. However, directly-modulated radioover- fiber (ROF) systems often suffer from inherent nonlinearities from directly-modulated lasers. Unlike ROF systems working at the single-band mode, the modulation nonlinearities in multi-band ROF systems can result in both in-band and cross-band nonlinear distortions. In order to address this issue, we have recently investigated the multi-band nonlinear behavior of directly-modulated DFB lasers based on multi-dimensional memory polynomial model. Based on this model, an efficient multi-dimensional baseband digital predistortion technique was developed and experimentally demonstrated for linearization of multi-band directly-modulated ROF systems.

  6. Ureaplasma parvum serovar 3 multiple banded antigen size variation after chronic intra-amniotic infection/colonization.

    PubMed

    Robinson, James W; Dando, Samantha J; Nitsos, Ilias; Newnham, John; Polglase, Graeme R; Kallapur, Suhas G; Pillow, J Jane; Kramer, Boris W; Jobe, Alan H; Payton, Diane; Knox, Christine L

    2013-01-01

    Ureaplasma species are the microorganisms most frequently associated with adverse pregnancy outcomes. The multiple banded antigen (MBA), a surface-exposed lipoprotein, is a key virulence factor of ureaplasmas. The MBA demonstrates size variation, which we have shown previously to be correlated with the severity of chorioamnion inflammation. We aimed to investigate U. parvum serovar 3 pathogenesis in vivo, using a sheep model, by investigating: MBA variation after long term (chronic) and short term (acute) durations of in utero ureaplasma infections, and the severity of chorioamnionitis and inflammation in other fetal tissues. Inocula of 2 × 10(7) colony-forming-units (CFU) of U. parvum serovar 3 (Up) or media controls (C) were injected intra-amniotically into pregnant ewes at one of three time points: day 55 (69d Up, n = 8; C69, n = 4); day 117 (7d Up, n = 8; C7, n = 2); and day 121 (3d Up, n = 8; C3, n = 2) of gestation (term = 145-150d). At day 124, preterm fetuses were delivered surgically. Samples of chorioamnion, fetal lung, and umbilical cord were: (i) snap frozen for subsequent ureaplasma culture, and (ii) fixed, embedded, sectioned and stained by haematoxylin and eosin stain for histological analysis. Selected fetal lung clinical ureaplasma isolates were cloned and filtered to obtain cultures from a single CFU. Passage 1 and clone 2 ureaplasma cultures were tested by western blot to demonstrate MBA variation. In acute durations of ureaplasma infection no MBA variants (3d Up) or very few MBA variants (7d Up) were present when compared to the original inoculum. However, numerous MBA size variants were generated in vivo (alike within contiguous tissues, amniotic fluid and fetal lung, but different variants were present within chorioamnion), during chronic, 69d exposure to ureaplasma infection. For the first time we have shown that the degree of ureaplasma MBA variation in vivo increased with the duration of gestation.

  7. Differential recognition of the multiple banded antigen isoforms across Ureaplasma parvum and Ureaplasma urealyticum species by monoclonal antibodies.

    PubMed

    Aboklaish, Ali F; Ahmed, Shatha; McAllister, Douglas; Cassell, Gail; Zheng, Xiaotian T; Spiller, Owen B

    2016-08-01

    Two separate species of Ureaplasma have been identified that infect humans: Ureaplasma parvum and Ureaplasma urealyticum. Most notably, these bacteria lack a cell wall and are the leading infectious organism associated with infection-related induction of preterm birth. Fourteen separate representative prototype bacterial strains, called serovars, are largely differentiated by the sequence of repeating units in the C-terminus of the major surface protein: multiple-banded antigen (MBA). Monoclonal antibodies that recognise single or small groups of serovars have been previously reported, but these reagents remain sequestered in individual research laboratories. Here we characterise a panel of commercially available monoclonal antibodies raised against the MBA and describe the first monoclonal antibody that cross-reacts by immunoblot with all serovars of U. parvum and U. urealyticum species. We also describe a recombinant MBA expressed by Escherichia coli which facilitated further characterisation by immunoblot and demonstrate immunohistochemistry of paraffin-embedded antigens. Immunoblot reactivity was validated against well characterised previously published monoclonal antibodies and individual commercial antibodies were found to recognise all U. parvum strains, only serovars 3 and 14 or only serovars 1 and 6, or all strains belonging to U. parvum and U. urealyticum. MBA mass was highly variable between strains, consistent with variation in the number of C-terminal repeats between strains. Antibody characterisation will enable future investigations to correlate severity of pathogenicity to MBA isoform number or mass, in addition to development of antibody-based diagnostics that will detect infection by all Ureaplasma species or alternately be able to differentiate between U. parvum, U. urealyticum or mixed infections. PMID:27208664

  8. Wireless Acoustic Measurement System

    NASA Technical Reports Server (NTRS)

    Anderson, Paul D.; Dorland, Wade D.; Jolly, Ronald L.

    2007-01-01

    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/ Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in the article on page 8. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro- ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that provides an intuitive graphical user interface through which an operator at the control server

  9. Wireless Acoustic Measurement System

    NASA Technical Reports Server (NTRS)

    Anderson, Paul D.; Dorland, Wade D.

    2005-01-01

    A prototype wireless acoustic measurement system (WAMS) is one of two main subsystems of the Acoustic Prediction/Measurement Tool, which comprises software, acoustic instrumentation, and electronic hardware combined to afford integrated capabilities for predicting and measuring noise emitted by rocket and jet engines. The other main subsystem is described in "Predicting Rocket or Jet Noise in Real Time" (SSC-00215-1), which appears elsewhere in this issue of NASA Tech Briefs. The WAMS includes analog acoustic measurement instrumentation and analog and digital electronic circuitry combined with computer wireless local-area networking to enable (1) measurement of sound-pressure levels at multiple locations in the sound field of an engine under test and (2) recording and processing of the measurement data. At each field location, the measurements are taken by a portable unit, denoted a field station. There are ten field stations, each of which can take two channels of measurements. Each field station is equipped with two instrumentation microphones, a micro-ATX computer, a wireless network adapter, an environmental enclosure, a directional radio antenna, and a battery power supply. The environmental enclosure shields the computer from weather and from extreme acoustically induced vibrations. The power supply is based on a marine-service lead-acid storage battery that has enough capacity to support operation for as long as 10 hours. A desktop computer serves as a control server for the WAMS. The server is connected to a wireless router for communication with the field stations via a wireless local-area network that complies with wireless-network standard 802.11b of the Institute of Electrical and Electronics Engineers. The router and the wireless network adapters are controlled by use of Linux-compatible driver software. The server runs custom Linux software for synchronizing the recording of measurement data in the field stations. The software includes a module that

  10. Amplitude of Low-Frequency Fluctuations in Multiple-Frequency Bands in Acute Mild Traumatic Brain Injury.

    PubMed

    Zhan, Jie; Gao, Lei; Zhou, Fuqing; Bai, Lijun; Kuang, Hongmei; He, Laichang; Zeng, Xianjun; Gong, Honghan

    2016-01-01

    Functional disconnectivity during the resting state has been observed in mild traumatic brain injury (mTBI) patients during the acute stage. However, it remains largely unknown whether the abnormalities are related to specific frequency bands of the low-frequency oscillations (LFO). Here, we used the amplitude of low-frequency fluctuations (ALFF) to examine the amplitudes of LFO in different frequency bands (slow-5: 0.01-0.027 Hz; slow-4: 0.027-0.073 Hz; and typical: 0.01-0.08 Hz) in patients with acute mTBI. A total of 24 acute mTBI patients and 24 age-, sex-, and education-matched healthy controls participated in this study. In the typical band, acute mTBI patients showed lower standardized ALFF in the right middle frontal gyrus and higher standardized ALFF in the right lingual/fusiform gyrus and left middle occipital gyrus. Further analyses showed that the difference between groups was concentrated in a narrower (slow-4) frequency band. In the slow-5 band, mTBI patients only exhibited higher standardized ALFF in the occipital areas. No significant correlation between the mini-mental state examination score and the standardized ALFF value was found in any brain region in the three frequency bands. Finally, no significant interaction between frequency bands and groups was found in any brain region. We concluded that the abnormality of spontaneous brain activity in acute mTBI patients existed in the frontal lobe as well as in distributed brain regions associated with integrative, sensory, and emotional roles, and the abnormal spontaneous neuronal activity in different brain regions could be better detected by the slow-4 band. These findings might contribute to a better understanding of local neural psychopathology of acute mTBI. Future studies should take the frequency bands into account when measuring intrinsic brain activity of mTBI patients. PMID:26869907

  11. Wireless Andrew.

    ERIC Educational Resources Information Center

    Fickes, Michael

    2000-01-01

    Describes the use of the Internet and laptops help Carnegie Mellon University students carry out sophisticated research anywhere on campus. How the university became a wireless community is discussed. (GR)

  12. Ureaplasma parvum Serovar 3 Multiple Banded Antigen Size Variation after Chronic Intra-Amniotic Infection/Colonization

    PubMed Central

    Robinson, James W.; Dando, Samantha J.; Nitsos, Ilias; Newnham, John; Polglase, Graeme R.; Kallapur, Suhas G.; Pillow, J. Jane; Kramer, Boris W.; Jobe, Alan H.; Payton, Diane; Knox, Christine L.

    2013-01-01

    Ureaplasma species are the microorganisms most frequently associated with adverse pregnancy outcomes. The multiple banded antigen (MBA), a surface-exposed lipoprotein, is a key virulence factor of ureaplasmas. The MBA demonstrates size variation, which we have shown previously to be correlated with the severity of chorioamnion inflammation. We aimed to investigate U. parvum serovar 3 pathogenesis in vivo, using a sheep model, by investigating: MBA variation after long term (chronic) and short term (acute) durations of in utero ureaplasma infections, and the severity of chorioamnionitis and inflammation in other fetal tissues. Inocula of 2×107 colony-forming-units (CFU) of U. parvum serovar 3 (Up) or media controls (C) were injected intra-amniotically into pregnant ewes at one of three time points: day 55 (69d Up, n = 8; C69, n = 4); day 117 (7d Up, n = 8; C7, n = 2); and day 121 (3d Up, n = 8; C3, n = 2) of gestation (term = 145–150d). At day 124, preterm fetuses were delivered surgically. Samples of chorioamnion, fetal lung, and umbilical cord were: (i) snap frozen for subsequent ureaplasma culture, and (ii) fixed, embedded, sectioned and stained by haematoxylin and eosin stain for histological analysis. Selected fetal lung clinical ureaplasma isolates were cloned and filtered to obtain cultures from a single CFU. Passage 1 and clone 2 ureaplasma cultures were tested by western blot to demonstrate MBA variation. In acute durations of ureaplasma infection no MBA variants (3d Up) or very few MBA variants (7d Up) were present when compared to the original inoculum. However, numerous MBA size variants were generated in vivo (alike within contiguous tissues, amniotic fluid and fetal lung, but different variants were present within chorioamnion), during chronic, 69d exposure to ureaplasma infection. For the first time we have shown that the degree of ureaplasma MBA variation in vivo increased with the duration of gestation. PMID:23638142

  13. The role of the multiple banded antigen of Ureaplasma parvum in intra-amniotic infection: major virulence factor or decoy?

    PubMed

    Dando, Samantha J; Nitsos, Ilias; Kallapur, Suhas G; Newnham, John P; Polglase, Graeme R; Pillow, J Jane; Jobe, Alan H; Timms, Peter; Knox, Christine L

    2012-01-01

    The multiple banded antigen (MBA) is a predicted virulence factor of Ureaplasma species. Antigenic variation of the MBA is a potential mechanism by which ureaplasmas avoid immune recognition and cause chronic infections of the upper genital tract of pregnant women. We tested whether the MBA is involved in the pathogenesis of intra-amniotic infection and chorioamnionitis by injecting virulent or avirulent-derived ureaplasma clones (expressing single MBA variants) into the amniotic fluid of pregnant sheep. At 55 days of gestation pregnant ewes (n = 20) received intra-amniotic injections of virulent-derived or avirulent-derived U. parvum serovar 6 strains (2×10⁴ CFU), or 10B medium (n = 5). Amniotic fluid was collected every two weeks post-infection and fetal tissues were collected at the time of surgical delivery of the fetus (140 days of gestation). Whilst chronic colonisation was established in the amniotic fluid of animals infected with avirulent-derived and virulent-derived ureaplasmas, the severity of chorioamnionitis and fetal inflammation was not different between these groups (p>0.05). MBA size variants (32-170 kDa) were generated in vivo in amniotic fluid samples from both the avirulent and virulent groups, whereas in vitro antibody selection experiments led to the emergence of MBA-negative escape variants in both strains. Anti-ureaplasma IgG antibodies were detected in the maternal serum of animals from the avirulent (40%) and virulent (55%) groups, and these antibodies correlated with increased IL-1β, IL-6 and IL-8 expression in chorioamnion tissue (p<0.05). We demonstrate that ureaplasmas are capable of MBA phase variation in vitro; however, ureaplasmas undergo MBA size variation in vivo, to potentially prevent eradication by the immune response. Size variation of the MBA did not correlate with the severity of chorioamnionitis. Nonetheless, the correlation between a maternal humoral response and the expression of chorioamnion cytokines is a

  14. The Role of the Multiple Banded Antigen of Ureaplasma parvum in Intra-Amniotic Infection: Major Virulence Factor or Decoy?

    PubMed Central

    Dando, Samantha J.; Nitsos, Ilias; Kallapur, Suhas G.; Newnham, John P.; Polglase, Graeme R.; Pillow, J. Jane; Jobe, Alan H.; Timms, Peter; Knox, Christine L.

    2012-01-01

    The multiple banded antigen (MBA) is a predicted virulence factor of Ureaplasma species. Antigenic variation of the MBA is a potential mechanism by which ureaplasmas avoid immune recognition and cause chronic infections of the upper genital tract of pregnant women. We tested whether the MBA is involved in the pathogenesis of intra-amniotic infection and chorioamnionitis by injecting virulent or avirulent-derived ureaplasma clones (expressing single MBA variants) into the amniotic fluid of pregnant sheep. At 55 days of gestation pregnant ewes (n = 20) received intra-amniotic injections of virulent-derived or avirulent-derived U. parvum serovar 6 strains (2×104 CFU), or 10B medium (n = 5). Amniotic fluid was collected every two weeks post-infection and fetal tissues were collected at the time of surgical delivery of the fetus (140 days of gestation). Whilst chronic colonisation was established in the amniotic fluid of animals infected with avirulent-derived and virulent-derived ureaplasmas, the severity of chorioamnionitis and fetal inflammation was not different between these groups (p>0.05). MBA size variants (32–170 kDa) were generated in vivo in amniotic fluid samples from both the avirulent and virulent groups, whereas in vitro antibody selection experiments led to the emergence of MBA-negative escape variants in both strains. Anti-ureaplasma IgG antibodies were detected in the maternal serum of animals from the avirulent (40%) and virulent (55%) groups, and these antibodies correlated with increased IL-1β, IL-6 and IL-8 expression in chorioamnion tissue (p<0.05). We demonstrate that ureaplasmas are capable of MBA phase variation in vitro; however, ureaplasmas undergo MBA size variation in vivo, to potentially prevent eradication by the immune response. Size variation of the MBA did not correlate with the severity of chorioamnionitis. Nonetheless, the correlation between a maternal humoral response and the expression of chorioamnion cytokines is a

  15. Band lineup in GaAs(1-x)Sbx/GaAs strained-layer multiple quantum wells grown by molecular-beam epitaxy

    NASA Technical Reports Server (NTRS)

    Ji, G.; Agarwala, S.; Huang, D.; Chyi, J.; Morkoc, H.

    1988-01-01

    GaAs(1-x)Sbx/GaAs strained-layer multiple quantum wells have been grown by molecular-beam epitaxy and characterized by room-temperature photoreflectance (PR). The PR spectra denote that high-quality layers can be grown in the GaAs(1-x)Sbx/GaAs system. The method for determining the band offset Q(vh) is discussed in this strained-layer system.

  16. Modeling the effect of native and laser-induced states on the dielectric breakdown of wide band gap optical materials by multiple subpicosecond laser pulses

    SciTech Connect

    Emmert, Luke A.; Mero, Mark; Rudolph, Wolfgang

    2010-08-15

    A model for the multiple-pulse laser-induced breakdown behavior of dielectrics is presented. It is based on a critical conduction band (CB) electron density leading to dielectric breakdown. The evolution of the CB electron density during the pulse train is calculated using rate equations involving transitions between band and mid-gap states (native and laser-induced). Using realistic estimations for the trap density and ionization cross-section, the model is able to reproduce the experimentally observed drop in the multiple-pulse damage threshold relative to the single-pulse value, as long as the CB electron density is controlled primarily by avalanche ionization seeded by multiphoton ionization of the traps and the valence band. The model shows that at long pulse duration, the breakdown threshold becomes more sensitive to presence of traps close (within one photon energy) to the CB. The effect of native and laser-induced defects can be distinguished by their saturation behavior. Finally, measurements of the multiple-pulse damage threshold of hafnium oxide films are used to illustrate the application of the model.

  17. Ultra-wideband microwave absorber by connecting multiple absorption bands of two different-sized hyperbolic metamaterial waveguide arrays

    NASA Astrophysics Data System (ADS)

    Yin, Xiang; Long, Chang; Li, Junhao; Zhu, Hua; Chen, Lin; Guan, Jianguo; Li, Xun

    2015-10-01

    Microwave absorbers have important applications in various areas including stealth, camouflage, and antenna. Here, we have designed an ultra-broadband light absorber by integrating two different-sized tapered hyperbolic metamaterial (HMM) waveguides, each of which has wide but different absorption bands due to broadband slow-light response, into a unit cell. Both the numerical and experimental results demonstrate that in such a design strategy, the low absorption bands between high absorption bands with a single-sized tapered HMM waveguide array can be effectively eliminated, resulting in a largely expanded absorption bandwidth ranging from 2.3 to 40 GHz. The presented ultra-broadband light absorber is also insensitive to polarization and robust against incident angle. Our results offer a further step in developing practical artificial electromagnetic absorbers, which will impact a broad range of applications at microwave frequencies.

  18. Ultra-wideband microwave absorber by connecting multiple absorption bands of two different-sized hyperbolic metamaterial waveguide arrays.

    PubMed

    Yin, Xiang; Long, Chang; Li, Junhao; Zhu, Hua; Chen, Lin; Guan, Jianguo; Li, Xun

    2015-10-19

    Microwave absorbers have important applications in various areas including stealth, camouflage, and antenna. Here, we have designed an ultra-broadband light absorber by integrating two different-sized tapered hyperbolic metamaterial (HMM) waveguides, each of which has wide but different absorption bands due to broadband slow-light response, into a unit cell. Both the numerical and experimental results demonstrate that in such a design strategy, the low absorption bands between high absorption bands with a single-sized tapered HMM waveguide array can be effectively eliminated, resulting in a largely expanded absorption bandwidth ranging from 2.3 to 40 GHz. The presented ultra-broadband light absorber is also insensitive to polarization and robust against incident angle. Our results offer a further step in developing practical artificial electromagnetic absorbers, which will impact a broad range of applications at microwave frequencies.

  19. Ultra-wideband microwave absorber by connecting multiple absorption bands of two different-sized hyperbolic metamaterial waveguide arrays.

    PubMed

    Yin, Xiang; Long, Chang; Li, Junhao; Zhu, Hua; Chen, Lin; Guan, Jianguo; Li, Xun

    2015-01-01

    Microwave absorbers have important applications in various areas including stealth, camouflage, and antenna. Here, we have designed an ultra-broadband light absorber by integrating two different-sized tapered hyperbolic metamaterial (HMM) waveguides, each of which has wide but different absorption bands due to broadband slow-light response, into a unit cell. Both the numerical and experimental results demonstrate that in such a design strategy, the low absorption bands between high absorption bands with a single-sized tapered HMM waveguide array can be effectively eliminated, resulting in a largely expanded absorption bandwidth ranging from 2.3 to 40 GHz. The presented ultra-broadband light absorber is also insensitive to polarization and robust against incident angle. Our results offer a further step in developing practical artificial electromagnetic absorbers, which will impact a broad range of applications at microwave frequencies. PMID:26477740

  20. Ultra-wideband microwave absorber by connecting multiple absorption bands of two different-sized hyperbolic metamaterial waveguide arrays

    PubMed Central

    Yin, Xiang; Long, Chang; Li, Junhao; Zhu, Hua; Chen, Lin; Guan, Jianguo; Li, Xun

    2015-01-01

    Microwave absorbers have important applications in various areas including stealth, camouflage, and antenna. Here, we have designed an ultra-broadband light absorber by integrating two different-sized tapered hyperbolic metamaterial (HMM) waveguides, each of which has wide but different absorption bands due to broadband slow-light response, into a unit cell. Both the numerical and experimental results demonstrate that in such a design strategy, the low absorption bands between high absorption bands with a single-sized tapered HMM waveguide array can be effectively eliminated, resulting in a largely expanded absorption bandwidth ranging from 2.3 to 40 GHz. The presented ultra-broadband light absorber is also insensitive to polarization and robust against incident angle. Our results offer a further step in developing practical artificial electromagnetic absorbers, which will impact a broad range of applications at microwave frequencies. PMID:26477740

  1. System and method for time synchronization in a wireless network

    DOEpatents

    Gonia, Patrick S.; Kolavennu, Soumitri N.; Mahasenan, Arun V.; Budampati, Ramakrishna S.

    2010-03-30

    A system includes multiple wireless nodes forming a cluster in a wireless network, where each wireless node is configured to communicate and exchange data wirelessly based on a clock. One of the wireless nodes is configured to operate as a cluster master. Each of the other wireless nodes is configured to (i) receive time synchronization information from a parent node, (ii) adjust its clock based on the received time synchronization information, and (iii) broadcast time synchronization information based on the time synchronization information received by that wireless node. The time synchronization information received by each of the other wireless nodes is based on time synchronization information provided by the cluster master so that the other wireless nodes substantially synchronize their clocks with the clock of the cluster master.

  2. Wireless Communications

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A technology utilization project led to the commercial adaptation of a Space Shuttle Orbiter wireless infrared voice communications system. The technology was adapted to a LAN system by Wilton Industries, one of the participants. Because the system is cable-free, installation charges are saved, and it can be used where cable is impractical. Resultant products include the IRplex 6000. Transceivers can be located anywhere and can include mobile receivers. The system provides wireless LAN coverage up to 44,000 square feet. applications include stock exchange communications, trade shows, emergency communications, etc.

  3. Fast Hearing-Threshold Estimation Using Multiple Auditory Steady-State Responses with Narrow-Band Chirps and Adaptive Stimulus Patterns

    PubMed Central

    Mühler, Roland; Mentzel, Katrin; Verhey, Jesko

    2012-01-01

    This paper describes the estimation of hearing thresholds in normal-hearing and hearing-impaired subjects on the basis of multiple-frequency auditory steady-state responses (ASSRs). The ASSR was measured using two new techniques: (i) adaptive stimulus patterns and (ii) narrow-band chirp stimuli. ASSR thresholds in 16 normal-hearing and 16 hearing-impaired adults were obtained simultaneously at both ears at 500, 1000, 2000, and 4000 Hz, using a multiple-frequency stimulus built up of four one-octave-wide narrow-band chirps with a repetition rate of 40 Hz. A statistical test in the frequency domain was used to detect the response. The recording of the steady-state responses was controlled in eight independent recording channels with an adaptive, semiautomatic algorithm. The average differences between the behavioural hearing thresholds and the ASSR threshold estimate were 10, 8, 13, and 15 dB for test frequencies of 500, 1000, 2000, and 4000 Hz, respectively. The average overall test duration of 18.6 minutes for the threshold estimations at the four frequencies and both ears demonstrates the benefit of an adaptive recording algorithm and the efficiency of optimised narrow-band chirp stimuli. PMID:22619622

  4. A wireless robot for networked laparoscopy.

    PubMed

    Castro, Cristian A; Alqassis, Adham; Smith, Sara; Ketterl, Thomas; Sun, Yu; Ross, Sharona; Rosemurgy, Alexander; Savage, Peter P; Gitlin, Richard D

    2013-04-01

    State-of-the-art laparoscopes for minimally invasive abdominal surgery are encumbered by cabling for power, video, and light sources. Although these laparoscopes provide good image quality, they interfere with surgical instruments, occupy a trocar port, require an assistant in the operating room to control the scope, have a very limited field of view, and are expensive. MARVEL is a wireless Miniature Anchored Robotic Videoscope for Expedited Laparoscopy that addresses these limitations by providing an inexpensive in vivo wireless camera module (CM) that eliminates the surgical-tool bottleneck experienced by surgeons in current laparoscopic endoscopic single-site (LESS) procedures. The MARVEL system includes 1) multiple CMs that feature a wirelessly controlled pan/tilt camera platform, which enable a full hemisphere field of view inside the abdominal cavity, wirelessly adjustable focus, and a multiwavelength illumination control system; 2) a master control module that provides a near-zero latency video wireless communications link, independent wireless control for multiple MARVEL CMs, digital zoom; and 3) a wireless human-machine interface that gives the surgeon full control over CM functionality. The research reported in this paper is the first step in developing a suite of semiautonomous wirelessly controlled and networked robotic cyber-physical devices to enable a paradigm shift in minimally invasive surgery and other domains such as wireless body area networks. PMID:23232365

  5. New Methods and Models in Wireless Networks: Multigraphs--Games--Mechanism Design

    ERIC Educational Resources Information Center

    Tran, Dung Trung

    2010-01-01

    The recent evolution of wireless technology makes wireless devices ever more powerful and intelligent. One trend is that wireless devices are becoming more inexpensive and more diverse. As a result, new technologies make it possible to equip wireless nodes with several radio transmitters/receivers. Each radio may support multiple channels which…

  6. Generation of multiple spectral bands in a diode-pumped self-mode-locked Nd:YAP laser

    NASA Astrophysics Data System (ADS)

    Huang, Y. J.; Tzeng, Y. S.; Cho, H. H.; Chen, Y. F.; Chen, W. D.; Zhang, G.; Chen, T. C.

    2016-02-01

    A single- and multispectral-band diode end-pumped self-mode-locked Nd:YAP laser is originally demonstrated with an intracavity etalon to properly control the gain-to-loss ratios among the intermanifold lines on the 4F3/2  →  4I11/2 transition level. With a pulse repetition rate of 5.07 GHz, the shortest pulse durations under the single-spectral-band operation are achieved to be 11.1 ps at 1073 nm, 10.9 ps at 1080 nm, and 15.1 ps at 1084 nm, respectively. Moreover, the temporal overlapping of the multispectral-band pulses is experimentally found to lead to the generation of an intensity fringe pattern in the autocorrelation trace with the optical-beat frequency reaching several terahertz. A simple mathematical model is developed to elucidate the formation of a train of optical-beat pulses.

  7. Wireless Protection.

    ERIC Educational Resources Information Center

    Conforti, Fred

    2003-01-01

    Discusses wireless access-control equipment in the school and university setting, particularly the integrated reader lock at the door with a panel interface module at the control panel. Describes its benefits, how it works, and its reliability and security. (EV)

  8. Wireless Technician

    ERIC Educational Resources Information Center

    Tech Directions, 2011

    2011-01-01

    One of the hottest areas in technology is invisible. Wireless communications allow people to transmit voice messages, data, and other signals through the air without physically connecting senders to receivers with cables or wires. And the technology is spreading at lightning speed. Cellular phones, personal digital assistants, and wireless…

  9. Wireless Tots

    ERIC Educational Resources Information Center

    Scott, Lee-Allison

    2003-01-01

    The first wireless technology program for preschoolers was implemented in January at the Primrose School at Bentwater in Atlanta, Georgia, a new corporate school operated by Primrose School Franchising Co. The new school serves as a testing and training facility for groundbreaking educational approaches, including emerging innovations in…

  10. Wireless Seismometer for Venus

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Scardelletti, Maximilian C.; Taylor, Brandt; Beard, Steve; Clougherty, Brian; Meredith, Roger D.; Beheim, Glenn M.; Kiefer, Walter S.; Hunter, Gary W.

    2014-01-01

    Measuring the seismic activity of Venus is critical to understanding its composition and interior dynamics. Because Venus has an average surface temperature of 462 C and the challenge of providing cooling to multiple seismometers, a high temperature, wireless sensor using a wide bandgap semiconductor is an attractive option. This paper presents progress towards a seismometer sensor with wireless capabilities for Venus applications. A variation in inductance of a coil caused by a 1 cm movement of a ferrite probe held in the coil and attached to a balanced leaf-spring seismometer causes a variation of 80 MHz in the transmitted signal from the oscillator sensor system at 420 C, which correlates to a 10 kHz mm sensitivity when the ferrite probe is located at the optimum location in the coil.

  11. Unpolarized emissivity with shadow and multiple reflections from random rough surfaces with the geometric optics approximation: application to Gaussian sea surfaces in the infrared band.

    PubMed

    Bourlier, Christophe

    2006-08-20

    The emissivity from a stationary random rough surface is derived by taking into account the multiple reflections and the shadowing effect. The model is applied to the ocean surface. The geometric optics approximation is assumed to be valid, which means that the rough surface is modeled as a collection of facets reflecting locally the light in the specular direction. In particular, the emissivity with zero, single, and double reflections are analytically calculated, and each contribution is studied numerically by considering a 1D sea surface observed in the near infrared band. The model is also compared with results computed from a Monte Carlo ray-tracing method. PMID:16892130

  12. Compact Ultra Wide Band Microstrip Bandpass Filter Based on Multiple-Mode Resonator and Modified Complementary Split Ring Resonator

    PubMed Central

    Marcotegui, J. Antonio; Illescas, Jesús Miguel; Estevez, Aritz

    2013-01-01

    A new class of broadband microstrip filters for Ultra Wide Band (UWB) applications is proposed. In the design, different stages of parallel-coupled microstrip line and other stages with a Modified Complementary Split Ring Resonator (MCSRR)—a concept proposed here for the first time—are adjusted to obtain the desired response with broadband, sharp rejection, low insertion loss, and low return loss. Full wave simulation results as well as measurement results from fabricated prototypes are presented, showing good agreement. The proposed technique offers a new alternative to implement low-cost high-performance filter devices, applicable to a wide range of communication systems. PMID:24319366

  13. CSF oligoclonal banding

    MedlinePlus

    ... system. Oligoclonal bands may be a sign of multiple sclerosis. How the Test is Performed A sample of ... Performed This test helps support the diagnosis of multiple sclerosis (MS). However, it does not confirm the diagnosis. ...

  14. Strain induced variations in band offsets and built-in electric fields in InGaN/GaN multiple quantum wells

    NASA Astrophysics Data System (ADS)

    Dong, L.; Mantese, J. V.; Avrutin, V.; Özgür, Ü.; Morkoç, H.; Alpay, S. P.

    2013-07-01

    The band structure, quantum confinement of charge carriers, and their localization affect the optoelectronic properties of compound semiconductor heterostructures and multiple quantum wells (MQWs). We present here the results of a systematic first-principles based density functional theory (DFT) investigation of the dependence of the valence band offsets and band bending in polar and non-polar strain-free and in-plane strained heteroepitaxial InxGa1-xN(InGaN)/GaN multilayers on the In composition and misfit strain. The results indicate that for non-polar m-plane configurations with [12¯10]InGaN//[12¯10]GaN and [0001]InGaN//[0001]GaN epitaxial alignments, the valence band offset changes linearly from 0 to 0.57 eV as the In composition is varied from 0 (GaN) to 1 (InN). These offsets are relatively insensitive to the misfit strain between InGaN and GaN. On the other hand, for polar c-plane strain-free heterostructures with [101¯0]InGaN//[101¯0]GaN and [12¯10]InGaN//[12¯10]GaN epitaxial alignments, the valence band offset increases nonlinearly from 0 eV (GaN) to 0.90 eV (InN). This is significantly reduced beyond x ≥ 0.5 by the effect of the equi-biaxial misfit strain. Thus, our results affirm that a combination of mechanical boundary conditions, epitaxial orientation, and variation in In concentration can be used as design parameters to rapidly tailor the band offsets in InGaN/GaN MQWs. Typically, calculations of the built-in electric field in complex semiconductor structures often must rely upon sequential optimization via repeated ab initio simulations. Here, we develop a formalism that augments such first-principles computations by including an electrostatic analysis (ESA) using Maxwell and Poisson's relations, thereby converting laborious DFT calculations into finite difference equations that can be rapidly solved. We use these tools to determine the bound sheet charges and built-in electric fields in polar epitaxial InGaN/GaN MQWs on c-plane Ga

  15. Design and Fabrication of Monolithically-Integrated Laterally-Arrayed Multiple Band Gap Solar Cells using Composition-Graded Alloy Nanowires for Spectrum-Splitting Photovoltaic Systems

    NASA Astrophysics Data System (ADS)

    Caselli, Derek

    This dissertation aims to demonstrate a new approach to fabricating solar cells for spectrum-splitting photovoltaic systems with the potential to reduce their cost and complexity of manufacturing, called Monolithically Integrated Laterally Arrayed Multiple Band gap (MILAMB) solar cells. Single crystal semiconductor alloy nanowire (NW) ensembles are grown with the alloy composition and band gap changing continuously across a broad range over the surface of a single substrate in a single, inexpensive growth step by the Dual-Gradient Method. The nanowire ensembles then serve as the absorbing materials in a set of solar cells for spectrum-splitting photovoltaic systems. Preliminary design and simulation studies based on Anderson's model band line-ups were undertaken for CdPbS and InGaN alloys. Systems of six subcells obtained efficiencies in the 32-38% range for CdPbS and 34-40% for InGaN at 1-240 suns, though both materials systems require significant development before these results could be achieved experimentally. For an experimental demonstration, CdSSe was selected due to its availability. Proof-of-concept CdSSe nanowire ensemble solar cells with two subcells were fabricated simultaneously on one substrate. I-V characterization under 1 sun AM1.5G conditions yielded open-circuit voltages (Voc) up to 307 and 173 mV and short-circuit current densities (Jsc) up to 0.091 and 0.974 mA/cm2 for the CdS- and CdSe-rich cells, respectively. Similar thin film cells were also fabricated for comparison. The nanowire cells showed substantially higher Voc than the film cells, which was attributed to higher material quality in the CdSSe absorber. I-V measurements were also conducted with optical filters to simulate a simple form of spectrum-splitting. The CdS-rich cells showed uniformly higher Voc and fill factor (FF) than the CdSe-rich cells, as expected due to their larger band gaps. This suggested higher power density was produced by the CdS-rich cells on the single

  16. Multi-service small-cell cloud wired/wireless access network based on tunable optical frequency comb

    NASA Astrophysics Data System (ADS)

    Xiang, Yu; Zhou, Kun; Yang, Liu; Pan, Lei; Liao, Zhen-wan; Zhang, Qiang

    2015-11-01

    In this paper, we demonstrate a novel multi-service wired/wireless integrated access architecture of cloud radio access network (C-RAN) based on radio-over-fiber passive optical network (RoF-PON) system, which utilizes scalable multiple- frequency millimeter-wave (MF-MMW) generation based on tunable optical frequency comb (TOFC). In the baseband unit (BBU) pool, the generated optical comb lines are modulated into wired, RoF and WiFi/WiMAX signals, respectively. The multi-frequency RoF signals are generated by beating the optical comb line pairs in the small cell. The WiFi/WiMAX signals are demodulated after passing through the band pass filter (BPF) and band stop filter (BSF), respectively, whereas the wired signal can be received directly. The feasibility and scalability of the proposed multi-service wired/wireless integrated C-RAN are confirmed by the simulations.

  17. The Severity of Chorioamnionitis in Pregnant Sheep Is Associated with In Vivo Variation of the Surface-Exposed Multiple-Banded Antigen/Gene of Ureaplasma parvum1

    PubMed Central

    Knox, Christine L.; Dando, Samantha J.; Nitsos, Ilias; Kallapur, Suhas G.; Jobe, Alan H.; Payton, Diane; Moss, Timothy J.M.; Newnham, John P.

    2010-01-01

    Ureaplasma species are the bacteria most frequently isolated from human amniotic fluid in asymptomatic pregnancies and placental infections. Ureaplasma parvum serovars 3 and 6 are the most prevalent serovars isolated from men and women. We hypothesized that the effects on the fetus and chorioamnion of chronic ureaplasma infection in amniotic fluid are dependent on the serovar, dose, and variation of the ureaplasma multiple-banded antigen (MBA) and mba gene. We injected high- or low-dose U. parvum serovar 3, serovar 6, or vehicle intra-amniotically into pregnant ewes at 55 days of gestation (term = 150 days) and examined the chorioamnion, amniotic fluid, and fetal lung tissue of animals delivered by cesarean section at 125 days of gestation. Variation of the multiple banded antigen/mba generated by serovar 3 and serovar 6 ureaplasmas in vivo were compared by PCR assay and Western blot. Ureaplasma inoculums demonstrated only one (serovar 3) or two (serovar 6) MBA variants in vitro, but numerous antigenic variants were generated in vivo: serovar 6 passage 1 amniotic fluid cultures contained more MBA size variants than serovar 3 (P = 0.005), and ureaplasma titers were inversely related to the number of variants (P = 0.025). The severity of chorioamnionitis varied between animals. Low numbers of mba size variants (five or fewer) within amniotic fluid were associated with severe inflammation, whereas the chorioamnion from animals with nine or more mba variants showed little or no inflammation. These differences in chorioamnion inflammation may explain why not all women with in utero Ureaplasma spp. experience adverse pregnancy outcomes. PMID:20519696

  18. The severity of chorioamnionitis in pregnant sheep is associated with in vivo variation of the surface-exposed multiple-banded antigen/gene of Ureaplasma parvum.

    PubMed

    Knox, Christine L; Dando, Samantha J; Nitsos, Ilias; Kallapur, Suhas G; Jobe, Alan H; Payton, Diane; Moss, Timothy J M; Newnham, John P

    2010-09-01

    Ureaplasma species are the bacteria most frequently isolated from human amniotic fluid in asymptomatic pregnancies and placental infections. Ureaplasma parvum serovars 3 and 6 are the most prevalent serovars isolated from men and women. We hypothesized that the effects on the fetus and chorioamnion of chronic ureaplasma infection in amniotic fluid are dependent on the serovar, dose, and variation of the ureaplasma multiple-banded antigen (MBA) and mba gene. We injected high- or low-dose U. parvum serovar 3, serovar 6, or vehicle intra-amniotically into pregnant ewes at 55 days of gestation (term = 150 days) and examined the chorioamnion, amniotic fluid, and fetal lung tissue of animals delivered by cesarean section at 125 days of gestation. Variation of the multiple banded antigen/mba generated by serovar 3 and serovar 6 ureaplasmas in vivo were compared by PCR assay and Western blot. Ureaplasma inoculums demonstrated only one (serovar 3) or two (serovar 6) MBA variants in vitro, but numerous antigenic variants were generated in vivo: serovar 6 passage 1 amniotic fluid cultures contained more MBA size variants than serovar 3 (P = 0.005), and ureaplasma titers were inversely related to the number of variants (P = 0.025). The severity of chorioamnionitis varied between animals. Low numbers of mba size variants (five or fewer) within amniotic fluid were associated with severe inflammation, whereas the chorioamnion from animals with nine or more mba variants showed little or no inflammation. These differences in chorioamnion inflammation may explain why not all women with in utero Ureaplasma spp. experience adverse pregnancy outcomes.

  19. Wireless Josephson amplifier

    SciTech Connect

    Narla, A.; Sliwa, K. M.; Hatridge, M.; Shankar, S.; Frunzio, L.; Schoelkopf, R. J.; Devoret, M. H.

    2014-06-09

    Josephson junction parametric amplifiers are playing a crucial role in the readout chain in superconducting quantum information experiments. However, their integration with current 3D cavity implementations poses the problem of transitioning between waveguide, coax cables, and planar circuits. Moreover, Josephson amplifiers require auxiliary microwave components, like directional couplers and/or hybrids, that are sources of spurious losses and impedance mismatches that limit measurement efficiency and amplifier tunability. We have developed a wireless architecture for these parametric amplifiers that eliminates superfluous microwave components and interconnects. This greatly simplifies their assembly and integration into experiments. We present an experimental realization of such a device operating in the 9–11 GHz band with about 100 MHz of amplitude gain-bandwidth product, on par with devices mounted in conventional sample holders. The simpler impedance environment presented to the amplifier also results in increased amplifier tunability.

  20. Third Generation Wireless Phone Threat Assessment for Aircraft Communication and Navigation Radios

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Koppen, Sandra V.; Smith, Laura J.; Williams, Reuben A.; Salud, Maria Theresa P.

    2005-01-01

    Radiated emissions in aircraft communication and navigation bands are measured from third generation (3G) wireless mobile phones. The two wireless technologies considered are the latest available to general consumers in the US. The measurements are conducted using reverberation chambers. The results are compared against baseline emissions from laptop computers and personal digital assistant devices that are currently allowed to operate on aircraft. Using existing interference path loss data and receivers interference threshold, a risk assessment is performed for several aircraft communication and navigation radio systems. In addition, cumulative interference effects of multiple similar devices are conservatively estimated or bounded. The effects are computed by summing the interference power from individual devices that is scaled according to the interference path loss at its location.

  1. Wireless Multiplexed Surface Acoustic Wave Sensors Project

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert C.

    2014-01-01

    Wireless Surface Acoustic Wave (SAW) Sensor is a new technology for obtaining multiple, real-time measurements under extreme environmental conditions. This project plans to develop a wireless multiplexed sensor system that uses SAW sensors, with no batteries or semiconductors, that are passive and rugged, can operate down to cryogenic temperatures and up to hundreds of degrees C, and can be used to sense a wide variety of parameters over reasonable distances (meters).

  2. A Priority-Based Adaptive MAC Protocol for Wireless Body Area Networks.

    PubMed

    Bhandari, Sabin; Moh, Sangman

    2016-01-01

    In wireless body area networks (WBANs), various sensors and actuators are placed on/inside the human body and connected wirelessly. WBANs have specific requirements for healthcare and medical applications, hence, standard protocols like the IEEE 802.15.4 cannot fulfill all the requirements. Consequently, many medium access control (MAC) protocols, mostly derived from the IEEE 802.15.4 superframe structure, have been studied. Nevertheless, they do not support a differentiated quality of service (QoS) for the various forms of traffic coexisting in a WBAN. In particular, a QoS-aware MAC protocol is essential for WBANs operating in the unlicensed Industrial, Scientific, and Medical (ISM) bands, because different wireless services like Bluetooth, WiFi, and Zigbee may coexist there and cause severe interference. In this paper, we propose a priority-based adaptive MAC (PA-MAC) protocol for WBANs in unlicensed bands, which allocates time slots dynamically, based on the traffic priority. Further, multiple channels are effectively utilized to reduce access delays in a WBAN, in the presence of coexisting systems. Our performance evaluation results show that the proposed PA-MAC outperforms the IEEE 802.15.4 MAC and the conventional priority-based MAC in terms of the average transmission time, throughput, energy consumption, and data collision ratio. PMID:26999162

  3. A Priority-Based Adaptive MAC Protocol for Wireless Body Area Networks.

    PubMed

    Bhandari, Sabin; Moh, Sangman

    2016-03-18

    In wireless body area networks (WBANs), various sensors and actuators are placed on/inside the human body and connected wirelessly. WBANs have specific requirements for healthcare and medical applications, hence, standard protocols like the IEEE 802.15.4 cannot fulfill all the requirements. Consequently, many medium access control (MAC) protocols, mostly derived from the IEEE 802.15.4 superframe structure, have been studied. Nevertheless, they do not support a differentiated quality of service (QoS) for the various forms of traffic coexisting in a WBAN. In particular, a QoS-aware MAC protocol is essential for WBANs operating in the unlicensed Industrial, Scientific, and Medical (ISM) bands, because different wireless services like Bluetooth, WiFi, and Zigbee may coexist there and cause severe interference. In this paper, we propose a priority-based adaptive MAC (PA-MAC) protocol for WBANs in unlicensed bands, which allocates time slots dynamically, based on the traffic priority. Further, multiple channels are effectively utilized to reduce access delays in a WBAN, in the presence of coexisting systems. Our performance evaluation results show that the proposed PA-MAC outperforms the IEEE 802.15.4 MAC and the conventional priority-based MAC in terms of the average transmission time, throughput, energy consumption, and data collision ratio.

  4. A Priority-Based Adaptive MAC Protocol for Wireless Body Area Networks

    PubMed Central

    Bhandari, Sabin; Moh, Sangman

    2016-01-01

    In wireless body area networks (WBANs), various sensors and actuators are placed on/inside the human body and connected wirelessly. WBANs have specific requirements for healthcare and medical applications, hence, standard protocols like the IEEE 802.15.4 cannot fulfill all the requirements. Consequently, many medium access control (MAC) protocols, mostly derived from the IEEE 802.15.4 superframe structure, have been studied. Nevertheless, they do not support a differentiated quality of service (QoS) for the various forms of traffic coexisting in a WBAN. In particular, a QoS-aware MAC protocol is essential for WBANs operating in the unlicensed Industrial, Scientific, and Medical (ISM) bands, because different wireless services like Bluetooth, WiFi, and Zigbee may coexist there and cause severe interference. In this paper, we propose a priority-based adaptive MAC (PA-MAC) protocol for WBANs in unlicensed bands, which allocates time slots dynamically, based on the traffic priority. Further, multiple channels are effectively utilized to reduce access delays in a WBAN, in the presence of coexisting systems. Our performance evaluation results show that the proposed PA-MAC outperforms the IEEE 802.15.4 MAC and the conventional priority-based MAC in terms of the average transmission time, throughput, energy consumption, and data collision ratio. PMID:26999162

  5. 47 CFR 15.216 - Disclosure requirements for wireless microphones and other low power auxiliary stations capable...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Disclosure requirements for wireless... wireless microphones and other low power auxiliary stations capable of operating in the core TV bands. (a... by the Wireless Telecommunications Bureau and the Consumer and Governmental Affairs Bureau, at...

  6. 47 CFR 95.1121 - Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Specific requirements for wireless medical... SERVICES Wireless Medical Telemetry Service (WMTS) General Provisions § 95.1121 Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427-1432 MHz bands. Due to the...

  7. 47 CFR 15.216 - Disclosure requirements for wireless microphones and other low power auxiliary stations capable...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Disclosure requirements for wireless... wireless microphones and other low power auxiliary stations capable of operating in the core TV bands. (a... by the Wireless Telecommunications Bureau and the Consumer and Governmental Affairs Bureau, at...

  8. 47 CFR 95.1121 - Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Specific requirements for wireless medical... SERVICES Wireless Medical Telemetry Service (WMTS) General Provisions § 95.1121 Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427-1432 MHz bands. Due to the...

  9. 47 CFR 15.216 - Disclosure requirements for wireless microphones and other low power auxiliary stations capable...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Disclosure requirements for wireless... wireless microphones and other low power auxiliary stations capable of operating in the core TV bands. (a... by the Wireless Telecommunications Bureau and the Consumer and Governmental Affairs Bureau, at...

  10. 47 CFR 95.1121 - Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Specific requirements for wireless medical... SERVICES Wireless Medical Telemetry Service (WMTS) General Provisions § 95.1121 Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427-1432 MHz bands. Due to the...

  11. 47 CFR 95.1121 - Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Specific requirements for wireless medical... SERVICES Wireless Medical Telemetry Service (WMTS) General Provisions § 95.1121 Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427-1432 MHz bands. Due to the...

  12. 47 CFR 15.216 - Disclosure requirements for wireless microphones and other low power auxiliary stations capable...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Disclosure requirements for wireless... wireless microphones and other low power auxiliary stations capable of operating in the core TV bands. (a... by the Wireless Telecommunications Bureau and the Consumer and Governmental Affairs Bureau, at...

  13. 47 CFR 95.1121 - Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Specific requirements for wireless medical... SERVICES Wireless Medical Telemetry Service (WMTS) General Provisions § 95.1121 Specific requirements for wireless medical telemetry devices operating in the 1395-1400 and 1427-1432 MHz bands. Due to the...

  14. NASA Lunar Base Wireless System Propagation Analysis

    NASA Technical Reports Server (NTRS)

    Hwu, Shian U.; Upanavage, Matthew; Sham, Catherine C.

    2007-01-01

    There have been many radio wave propagation studies using both experimental and theoretical techniques over the recent years. However, most of studies have been in support of commercial cellular phone wireless applications. The signal frequencies are mostly at the commercial cellular and Personal Communications Service bands. The antenna configurations are mostly one on a high tower and one near the ground to simulate communications between a cellular base station and a mobile unit. There are great interests in wireless communication and sensor systems for NASA lunar missions because of the emerging importance of establishing permanent lunar human exploration bases. Because of the specific lunar terrain geometries and RF frequencies of interest to the NASA missions, much of the published literature for the commercial cellular and PCS bands of 900 and 1800 MHz may not be directly applicable to the lunar base wireless system and environment. There are various communication and sensor configurations required to support all elements of a lunar base. For example, the communications between astronauts, between astronauts and the lunar vehicles, between lunar vehicles and satellites on the lunar orbits. There are also various wireless sensor systems among scientific, experimental sensors and data collection ground stations. This presentation illustrates the propagation analysis of the lunar wireless communication and sensor systems taking into account the three dimensional terrain multipath effects. It is observed that the propagation characteristics are significantly affected by the presence of the lunar terrain. The obtained results indicate the lunar surface material, terrain geometry and antenna location are the important factors affecting the propagation characteristics of the lunar wireless systems. The path loss can be much more severe than the free space propagation and is greatly affected by the antenna height, surface material and operating frequency. The

  15. Wireless steganography

    NASA Astrophysics Data System (ADS)

    Agaian, Sos S.; Akopian, David; D'Souza, Sunil

    2006-02-01

    Modern mobile devices are some of the most technologically advanced devices that people use on a daily basis and the current trends in mobile phone technology indicate that tasks achievable by mobile devices will soon exceed our imagination. This paper undertakes a case study of the development and implementation of one of the first known steganography (data hiding) applications on a mobile device. Steganography is traditionally accomplished using the high processing speeds of desktop or notebook computers. With the introduction of mobile platform operating systems, there arises an opportunity for the users to develop and embed their own applications. We take advantage of this opportunity with the introduction of wireless steganographic algorithms. Thus we demonstrates that custom applications, popular with security establishments, can be developed also on mobile systems independent of both the mobile device manufacturer and mobile service provider. For example, this might be a very important feature if the communication is to be controlled exclusively by authorized personnel. The paper begins by reviewing the technological capabilities of modern mobile devices. Then we address a suitable development platform which is based on Symbian TM/Series60 TM architecture. Finally, two data hiding applications developed for Symbian TM/Series60 TM mobile phones are presented.

  16. Community Wireless Networks

    ERIC Educational Resources Information Center

    Feld, Harold

    2005-01-01

    With increasing frequency, communities are seeing the arrival of a new class of noncommercial broadband providers: community wireless networks (CWNs). Utilizing the same wireless technologies that many colleges and universities have used to create wireless networks on campus, CWNs are creating broadband access for free or at costs well below…

  17. A Reliable Wireless Control System for Tomato Hydroponics.

    PubMed

    Ibayashi, Hirofumi; Kaneda, Yukimasa; Imahara, Jungo; Oishi, Naoki; Kuroda, Masahiro; Mineno, Hiroshi

    2016-05-05

    Agricultural systems using advanced information and communication (ICT) technology can produce high-quality crops in a stable environment while decreasing the need for manual labor. The system collects a wide variety of environmental data and provides the precise cultivation control needed to produce high value-added crops; however, there are the problems of packet transmission errors in wireless sensor networks or system failure due to having the equipment in a hot and humid environment. In this paper, we propose a reliable wireless control system for hydroponic tomato cultivation using the 400 MHz wireless band and the IEEE 802.15.6 standard. The 400 MHz band, which is lower than the 2.4 GHz band, has good obstacle diffraction, and zero-data-loss communication is realized using the guaranteed time-slot method supported by the IEEE 802.15.6 standard. In addition, this system has fault tolerance and a self-healing function to recover from faults such as packet transmission failures due to deterioration of the wireless communication quality. In our basic experiments, the 400 MHz band wireless communication was not affected by the plants' growth, and the packet error rate was less than that of the 2.4 GHz band. In summary, we achieved a real-time hydroponic liquid supply control with no data loss by applying a 400 MHz band WSN to hydroponic tomato cultivation.

  18. A Reliable Wireless Control System for Tomato Hydroponics.

    PubMed

    Ibayashi, Hirofumi; Kaneda, Yukimasa; Imahara, Jungo; Oishi, Naoki; Kuroda, Masahiro; Mineno, Hiroshi

    2016-01-01

    Agricultural systems using advanced information and communication (ICT) technology can produce high-quality crops in a stable environment while decreasing the need for manual labor. The system collects a wide variety of environmental data and provides the precise cultivation control needed to produce high value-added crops; however, there are the problems of packet transmission errors in wireless sensor networks or system failure due to having the equipment in a hot and humid environment. In this paper, we propose a reliable wireless control system for hydroponic tomato cultivation using the 400 MHz wireless band and the IEEE 802.15.6 standard. The 400 MHz band, which is lower than the 2.4 GHz band, has good obstacle diffraction, and zero-data-loss communication is realized using the guaranteed time-slot method supported by the IEEE 802.15.6 standard. In addition, this system has fault tolerance and a self-healing function to recover from faults such as packet transmission failures due to deterioration of the wireless communication quality. In our basic experiments, the 400 MHz band wireless communication was not affected by the plants' growth, and the packet error rate was less than that of the 2.4 GHz band. In summary, we achieved a real-time hydroponic liquid supply control with no data loss by applying a 400 MHz band WSN to hydroponic tomato cultivation. PMID:27164105

  19. A Reliable Wireless Control System for Tomato Hydroponics

    PubMed Central

    Ibayashi, Hirofumi; Kaneda, Yukimasa; Imahara, Jungo; Oishi, Naoki; Kuroda, Masahiro; Mineno, Hiroshi

    2016-01-01

    Agricultural systems using advanced information and communication (ICT) technology can produce high-quality crops in a stable environment while decreasing the need for manual labor. The system collects a wide variety of environmental data and provides the precise cultivation control needed to produce high value-added crops; however, there are the problems of packet transmission errors in wireless sensor networks or system failure due to having the equipment in a hot and humid environment. In this paper, we propose a reliable wireless control system for hydroponic tomato cultivation using the 400 MHz wireless band and the IEEE 802.15.6 standard. The 400 MHz band, which is lower than the 2.4 GHz band, has good obstacle diffraction, and zero-data-loss communication is realized using the guaranteed time-slot method supported by the IEEE 802.15.6 standard. In addition, this system has fault tolerance and a self-healing function to recover from faults such as packet transmission failures due to deterioration of the wireless communication quality. In our basic experiments, the 400 MHz band wireless communication was not affected by the plants’ growth, and the packet error rate was less than that of the 2.4 GHz band. In summary, we achieved a real-time hydroponic liquid supply control with no data loss by applying a 400 MHz band WSN to hydroponic tomato cultivation. PMID:27164105

  20. Realization of band gap shrinkage to the spectral characteristics of high-luminous-efficiency 658 nm AlGaInP/GaInP multiple quantum well lasers at room temperatures

    NASA Astrophysics Data System (ADS)

    Chackrabarti, Santosh; Zargar, Rayees A.; Bansal, Jyoti; Zaker, Tho-alfiqar A.; Hafiz, A. K.

    2016-08-01

    The temperature dependent spectral shifts in 658 nm AlGaInP multiple quantum well (MQW) red laser diodes due to band gap narrowing at room temperatures (5 °Csbnd 45 °C) is reported. The density of states effective mass approximation and the conduction band effective mass approximation are employed to formulate the carrier concentrations. The spectral shift mechanism is explored with a threshold current density of 42.28 kA/cm2 and a good characteristic temperature of 149 K. The photoluminescence (PL) peak intensity shifts towards the higher wavelength(red shift) and the full width at half maximum (FWHM) increases with the increase in temperature. The band gap narrowing value determined by a simple formula amounts to 67.4 meV and displays N1/3 dependence at higher densities. The carrier density dependence conveys that the red shift of the spectral emission is due to band gap narrowing.

  1. 47 CFR 27.1300 - 600 MHz band subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... licenses are subject to competitive bidding. The general competitive bidding procedures set forth in 47 CFR... SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 600 MHz Band § 27.1300 600 MHz band subject...

  2. Wireless adiabatic power transfer

    SciTech Connect

    Rangelov, A.A.; Suchowski, H.; Silberberg, Y.; Vitanov, N.V.

    2011-03-15

    Research Highlights: > Efficient and robust mid-range wireless energy transfer between two coils. > The adiabatic energy transfer is analogous to adiabatic passage in quantum optics. > Wireless energy transfer is insensitive to any resonant constraints. > Wireless energy transfer is insensitive to noise in the neighborhood of the coils. - Abstract: We propose a technique for efficient mid-range wireless power transfer between two coils, by adapting the process of adiabatic passage for a coherently driven two-state quantum system to the realm of wireless energy transfer. The proposed technique is shown to be robust to noise, resonant constraints, and other interferences that exist in the neighborhood of the coils.

  3. A method to accurately quantitate intensities of (32)P-DNA bands when multiple bands appear in a single lane of a gel is used to study dNTP insertion opposite a benzo[a]pyrene-dG adduct by Sulfolobus DNA polymerases Dpo4 and Dbh.

    PubMed

    Sholder, Gabriel; Loechler, Edward L

    2015-01-01

    Quantitating relative (32)P-band intensity in gels is desired, e.g., to study primer-extension kinetics of DNA polymerases (DNAPs). Following imaging, multiple (32)P-bands are often present in lanes. Though individual bands appear by eye to be simple and well-resolved, scanning reveals they are actually skewed-Gaussian in shape and neighboring bands are overlapping, which complicates quantitation, because slower migrating bands often have considerable contributions from the trailing edges of faster migrating bands. A method is described to accurately quantitate adjacent (32)P-bands, which relies on having a standard: a simple skewed-Gaussian curve from an analogous pure, single-component band (e.g., primer alone). This single-component scan/curve is superimposed on its corresponding band in an experimentally determined scan/curve containing multiple bands (e.g., generated in a primer-extension reaction); intensity exceeding the single-component scan/curve is attributed to other components (e.g., insertion products). Relative areas/intensities are determined via pixel analysis, from which relative molarity of components is computed. Common software is used. Commonly used alternative methods (e.g., drawing boxes around bands) are shown to be less accurate. Our method was used to study kinetics of dNTP primer-extension opposite a benzo[a]pyrene-N(2)-dG-adduct with four DNAPs, including Sulfolobus solfataricus Dpo4 and Sulfolobus acidocaldarius Dbh. Vmax/Km is similar for correct dCTP insertion with Dpo4 and Dbh. Compared to Dpo4, Dbh misinsertion is slower for dATP (∼20-fold), dGTP (∼110-fold) and dTTP (∼6-fold), due to decreases in Vmax. These findings provide support that Dbh is in the same Y-Family DNAP class as eukaryotic DNAP κ and bacterial DNAP IV, which accurately bypass N(2)-dG adducts, as well as establish the scan-method described herein as an accurate method to quantitate relative intensity of overlapping bands in a single lane, whether generated

  4. A method to accurately quantitate intensities of (32)P-DNA bands when multiple bands appear in a single lane of a gel is used to study dNTP insertion opposite a benzo[a]pyrene-dG adduct by Sulfolobus DNA polymerases Dpo4 and Dbh.

    PubMed

    Sholder, Gabriel; Loechler, Edward L

    2015-01-01

    Quantitating relative (32)P-band intensity in gels is desired, e.g., to study primer-extension kinetics of DNA polymerases (DNAPs). Following imaging, multiple (32)P-bands are often present in lanes. Though individual bands appear by eye to be simple and well-resolved, scanning reveals they are actually skewed-Gaussian in shape and neighboring bands are overlapping, which complicates quantitation, because slower migrating bands often have considerable contributions from the trailing edges of faster migrating bands. A method is described to accurately quantitate adjacent (32)P-bands, which relies on having a standard: a simple skewed-Gaussian curve from an analogous pure, single-component band (e.g., primer alone). This single-component scan/curve is superimposed on its corresponding band in an experimentally determined scan/curve containing multiple bands (e.g., generated in a primer-extension reaction); intensity exceeding the single-component scan/curve is attributed to other components (e.g., insertion products). Relative areas/intensities are determined via pixel analysis, from which relative molarity of components is computed. Common software is used. Commonly used alternative methods (e.g., drawing boxes around bands) are shown to be less accurate. Our method was used to study kinetics of dNTP primer-extension opposite a benzo[a]pyrene-N(2)-dG-adduct with four DNAPs, including Sulfolobus solfataricus Dpo4 and Sulfolobus acidocaldarius Dbh. Vmax/Km is similar for correct dCTP insertion with Dpo4 and Dbh. Compared to Dpo4, Dbh misinsertion is slower for dATP (∼20-fold), dGTP (∼110-fold) and dTTP (∼6-fold), due to decreases in Vmax. These findings provide support that Dbh is in the same Y-Family DNAP class as eukaryotic DNAP κ and bacterial DNAP IV, which accurately bypass N(2)-dG adducts, as well as establish the scan-method described herein as an accurate method to quantitate relative intensity of overlapping bands in a single lane, whether generated

  5. DRB1*03:01 Haplotypes: Differential Contribution to Multiple Sclerosis Risk and Specific Association with the Presence of Intrathecal IgM Bands

    PubMed Central

    Cénit, M. Carmen; Urcelay, Elena; Arroyo, Rafael; Fernández, Óscar; Álvarez-Cermeño, José C.; Leyva, Laura

    2012-01-01

    Background Multiple sclerosis (MS) is a multifactorial disease with a genetic basis. The strongest associations with the disease lie in the Human Leukocyte Antigen (HLA) region. However, except for the DRB1*15:01 allele, the main risk factor associated to MS so far, no consistent effect has been described for any other variant. One example is HLA-DRB1*03:01, with a heterogeneous effect across populations and studies. We postulate that those discrepancies could be due to differences in the diverse haplotypes bearing that allele. Thus, we aimed at studying the association of DRB1*03:01 with MS susceptibility considering this allele globally and stratified by haplotypes. We also evaluated the association with the presence of oligoclonal IgM bands against myelin lipids (OCMB) in cerebrospinal fluid. Methods Genotyping of HLA-B, -DRB1 and -DQA1 was performed in 1068 MS patients and 624 ethnically matched healthy controls. One hundred and thirty-nine MS patients were classified according to the presence (M+, 58 patients)/absence (M−, 81 patients) of OCMB. Comparisons between groups (MS patients vs. controls and M+ vs. M−) were performed with the chi-square test or the Fisher exact test. Results Association of DRB1*03:01 with MS susceptibility was observed but with different haplotypic contribution, being the ancestral haplotype (AH) 18.2 the one causing the highest risk. Comparisons between M+, M− and controls showed that the AH 18.2 was affecting only M+ individuals, conferring a risk similar to that caused by DRB1*15:01. Conclusions The diverse DRB1*03:01-containing haplotypes contribute with different risk to MS susceptibility. The AH 18.2 causes the highest risk and affects only to individuals showing OCMB. PMID:22363536

  6. ASTRONOMY: Researchers Get Spectrum Bands.

    PubMed

    Taubes, G

    2000-06-23

    Radio astronomers have been in danger of losing a precious band of the electromagnetic spectrum--the millimeter wavelengths, which promise insight into subjects as diverse as the origins of life and the birth of stars--to the burgeoning telecommunications industry, as millimeter wavelengths also look promising for transmitting high-bandwidth wireless information over relatively short distances. Earlier this month, however, astronomers won an international agreement that guarantees critical wavelengths safe for research. PMID:17758893

  7. Growth of wireless technology in healthcare institutions.

    PubMed

    Riha, Chris

    2006-01-01

    As wireless technologies evolve and interoperate, the practical application for healthcare providers and organizations grows exponentially. By providing increased access to patient data, decision-making tools (e.g., computer aided decision systems such as ECG analysis programs), error reduction systems (i.e., pharmaceutical error prevention software), the benefits of wireless technology can be immense. However, as with all technological innovations, wireless systems must be carefully planned and managed. As the wireless spectrum becomes more crowded with both complementary and competing systems, bandwidth utilization and the potential for interference grows greatly. Clinical engineering personnel need to be actively involved in the management of wireless system management within a healthcare facility to avoid interference problems that could disrupt patient care, especially as the deployment of wireless systems expands. Additionally, public exposure to RF energy in a healthcare setting may need to be monitored and evaluated as the utilization of this energy spectrum continues to grow. All manufacturers of RF emitting devices are required to list the specific absorption rate of their specific device. However, there is no monitoring of the cumulative effect of multiple devices and systems. As of press time, this has not been an issue. But it is something to consider as we continue to find useful applications for this technology.

  8. Wireless mesh networks.

    PubMed

    Wang, Xinheng

    2008-01-01

    Wireless telemedicine using GSM and GPRS technologies can only provide low bandwidth connections, which makes it difficult to transmit images and video. Satellite or 3G wireless transmission provides greater bandwidth, but the running costs are high. Wireless networks (WLANs) appear promising, since they can supply high bandwidth at low cost. However, the WLAN technology has limitations, such as coverage. A new wireless networking technology named the wireless mesh network (WMN) overcomes some of the limitations of the WLAN. A WMN combines the characteristics of both a WLAN and ad hoc networks, thus forming an intelligent, large scale and broadband wireless network. These features are attractive for telemedicine and telecare because of the ability to provide data, voice and video communications over a large area. One successful wireless telemedicine project which uses wireless mesh technology is the Emergency Room Link (ER-LINK) in Tucson, Arizona, USA. There are three key characteristics of a WMN: self-organization, including self-management and self-healing; dynamic changes in network topology; and scalability. What we may now see is a shift from mobile communication and satellite systems for wireless telemedicine to the use of wireless networks based on mesh technology, since the latter are very attractive in terms of cost, reliability and speed.

  9. Evaluation of a 433 MHz Band Body Sensor Network for Biomedical Applications

    PubMed Central

    Kim, Saim; Brendle, Christian; Lee, Hyun-Young; Walter, Marian; Gloeggler, Sigrid; Krueger, Stefan; Leonhardt, Steffen

    2013-01-01

    Body sensor networks (BSN) are an important research topic due to various advantages over conventional measurement equipment. One main advantage is the feasibility to deploy a BSN system for 24/7 health monitoring applications. The requirements for such an application are miniaturization of the network nodes and the use of wireless data transmission technologies to ensure wearability and ease of use. Therefore, the reliability of such a system depends on the quality of the wireless data transmission. At present, most BSNs use ZigBee or other IEEE 802.15.4 based transmission technologies. Here, we evaluated the performance of a wireless transmission system of a novel BSN for biomedical applications in the 433 MHz ISM band, called Integrated Posture and Activity NEtwork by Medit Aachen (IPANEMA) BSN. The 433 MHz ISM band is used mostly by implanted sensors and thus allows easy integration of such into the BSN. Multiple measurement scenarios have been assessed, including varying antenna orientations, transmission distances and the number of network participants. The mean packet loss rate (PLR) was 0.63% for a single slave, which is comparable to IEEE 802.15.4 BSNs in the proximity of Bluetooth or WiFi networks. Secondly, an enhanced version is evaluated during on-body measurements with five slaves. The mean PLR results show a comparable good performance for measurements on a treadmill (2.5%), an outdoor track (3.4%) and in a climate chamber (1.5%). PMID:23344383

  10. Evaluation of a 433 MHz band body sensor network for biomedical applications.

    PubMed

    Kim, Saim; Brendle, Christian; Lee, Hyun-Young; Walter, Marian; Gloeggler, Sigrid; Krueger, Stefan; Leonhardt, Steffen

    2013-01-01

    Body sensor networks (BSN) are an important research topic due to various advantages over conventional measurement equipment. One main advantage is the feasibility to deploy a BSN system for 24/7 health monitoring applications. The requirements for such an application are miniaturization of the network nodes and the use of wireless data transmission technologies to ensure wearability and ease of use. Therefore, the reliability of such a system depends on the quality of the wireless data transmission. At present, most BSNs use ZigBee or other IEEE 802.15.4 based transmission technologies. Here, we evaluated the performance of a wireless transmission system of a novel BSN for biomedical applications in the 433MHz ISM band, called Integrated Posture and Activity NEtwork by Medit Aachen (IPANEMA) BSN. The 433MHz ISM band is used mostly by implanted sensors and thus allows easy integration of such into the BSN. Multiple measurement scenarios have been assessed, including varying antenna orientations, transmission distances and the number of network participants. The mean packet loss rate (PLR) was 0.63% for a single slave, which is comparable to IEEE 802.15.4 BSNs in the proximity of Bluetooth or WiFi networks. Secondly, an enhanced version is evaluated during on-body measurements with five slaves. The mean PLR results show a comparable good performance for measurements on a treadmill (2.5%), an outdoor track (3.4%) and in a climate chamber (1.5%). PMID:23344383

  11. Listening to Brain Microcircuits for Interfacing With External World-Progress in Wireless Implantable Microelectronic Neuroengineering Devices: Experimental systems are described for electrical recording in the brain using multiple microelectrodes and short range implantable or wearable broadcasting units.

    PubMed

    Nurmikko, Arto V; Donoghue, John P; Hochberg, Leigh R; Patterson, William R; Song, Yoon-Kyu; Bull, Christopher W; Borton, David A; Laiwalla, Farah; Park, Sunmee; Ming, Yin; Aceros, Juan

    2010-01-01

    Acquiring neural signals at high spatial and temporal resolution directly from brain microcircuits and decoding their activity to interpret commands and/or prior planning activity, such as motion of an arm or a leg, is a prime goal of modern neurotechnology. Its practical aims include assistive devices for subjects whose normal neural information pathways are not functioning due to physical damage or disease. On the fundamental side, researchers are striving to decipher the code of multiple neural microcircuits which collectively make up nature's amazing computing machine, the brain. By implanting biocompatible neural sensor probes directly into the brain, in the form of microelectrode arrays, it is now possible to extract information from interacting populations of neural cells with spatial and temporal resolution at the single cell level. With parallel advances in application of statistical and mathematical techniques tools for deciphering the neural code, extracted populations or correlated neurons, significant understanding has been achieved of those brain commands that control, e.g., the motion of an arm in a primate (monkey or a human subject). These developments are accelerating the work on neural prosthetics where brain derived signals may be employed to bypass, e.g., an injured spinal cord. One key element in achieving the goals for practical and versatile neural prostheses is the development of fully implantable wireless microelectronic "brain-interfaces" within the body, a point of special emphasis of this paper.

  12. Wireless microphone communication system telephonics P/N 484D000-1

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The wireless microphone is a lightweight, portable, wireless voice communications device for use by the crew of the space shuttle orbiter. The wireless microphone allows the crew to have normal hands-free voice communication while they are performing various mission activities. The unit is designed to transmit at 455 or 500 kilohertz and employs narrow band FM modulation. Two orthogonally placed antennas are used to insure good reception at the receiver.

  13. Wireless security in mobile health.

    PubMed

    Osunmuyiwa, Olufolabi; Ulusoy, Ali Hakan

    2012-12-01

    Mobile health (m-health) is an extremely broad term that embraces mobile communication in the health sector and data packaging. The four broad categories of wireless networks are wireless personal area network, wireless metropolitan area network, wireless wide area network, and wireless local area network. Wireless local area network is the most notable of the wireless networking tools obtainable in the health sector. Transfer of delicate and critical information on radio frequencies should be secure, and the right to use must be meticulous. This article covers the business opportunities in m-health, threats faced by wireless networks in hospitals, and methods of mitigating these threats.

  14. Wireless security in mobile health.

    PubMed

    Osunmuyiwa, Olufolabi; Ulusoy, Ali Hakan

    2012-12-01

    Mobile health (m-health) is an extremely broad term that embraces mobile communication in the health sector and data packaging. The four broad categories of wireless networks are wireless personal area network, wireless metropolitan area network, wireless wide area network, and wireless local area network. Wireless local area network is the most notable of the wireless networking tools obtainable in the health sector. Transfer of delicate and critical information on radio frequencies should be secure, and the right to use must be meticulous. This article covers the business opportunities in m-health, threats faced by wireless networks in hospitals, and methods of mitigating these threats. PMID:23234427

  15. 75 FR 9210 - Wireless Telecommunications Bureau Seeks Comment on Petition for Rulemaking Regarding 700 MHz...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-01

    ... paper copies. See Electronic Filing of Documents in Rulemaking Proceedings, 63 FR 24121 (1998... COMMISSION Wireless Telecommunications Bureau Seeks Comment on Petition for Rulemaking Regarding 700 MHz Band...: Notice. SUMMARY: The Wireless Telecommunications Bureau seeks comment on a petition for rulemaking...

  16. OIT Wireless Telemetry for Industrial Applications

    SciTech Connect

    Manges, WW

    2002-09-03

    networks to operate cooperatively in an environment that includes wireless LANs, wireless headsets, RF heating, wireless crane controls and many other users of the electromagnetic spectrum will probably be the most important issue we can address. A network of units (Figure 1) has been developed that demonstrates the feasibility of direct-sequence spread spectrum wireless sensor networking for industrial environments. The hardware consists of a group of reprogrammable transceivers that can act as sensor nodes or network nodes or both. These units and the team that built them are the heart of a test bed development system that has been used successfully in demonstrations at various industrial sites. As previously reported, these units have been successfully tested at a paper mill. More recently, these units were utilized in a permanent installation at a steel mill. Both of these applications demonstrated the ease with which a new network could be installed, and the reality that DSSS units can operate successfully in plants where narrow band transmitters had previously caused interference with plant operations.

  17. Feasibility studies for a wireless 60 GHz tracking detector readout

    NASA Astrophysics Data System (ADS)

    Dittmeier, S.; Schöning, A.; Soltveit, H. K.; Wiedner, D.

    2016-09-01

    The amount of data produced by highly granular silicon tracking detectors in high energy physics experiments poses a major challenge to readout systems. At high collision rates, e.g. at LHC experiments, only a small fraction of data can be read out with currently used technologies. To cope with the requirements of future or upgraded experiments new data transfer techniques are required which offer high data rates at low power and low material budget. Wireless technologies operating in the 60 GHz band or at higher frequencies offer high data rates and are thus a promising upcoming alternative to conventional data transmission via electrical cables or optical fibers. Using wireless technology, the amount of cables and connectors in detectors can be significantly reduced. Tracking detectors profit most from a reduced material budget as fewer secondary particle interactions (multiple Coulomb scattering, energy loss, etc.) improve the tracking performance in general. We present feasibility studies regarding the integration of the wireless technology at 60 GHz into a silicon tracking detector. We use spare silicon strip modules of the ATLAS experiment as test samples which are measured to be opaque in the 60 GHz range. The reduction of cross talk between links and the attenuation of reflections is studied. An estimate of the maximum achievable link density is given. It is shown that wireless links can be placed as close as 2 cm next to each other for a layer distance of 10 cm by exploiting one or several of the following measures: highly directive antennas, absorbers like graphite foam, linear polarization and frequency channeling. Combining these measures, a data rate area density of up to 11 Tb/(s·m2) seems feasible. In addition, two types of silicon sensors are tested under mm-wave irradiation in order to determine the influence of 60 GHz data transmission on the detector performance: an ATLAS silicon strip sensor module and an HV-MAPS prototype for the Mu3e

  18. Warming Up to Wireless

    ERIC Educational Resources Information Center

    Milner, Jacob

    2005-01-01

    In districts big and small across the U.S., students, teachers, and administrators alike have come to appreciate the benefits of wireless technology. Because the technology delivers Internet signals on airborne radio frequencies, wireless networking allows users of all portable devices to move freely on a school's campus and stay connected to the…

  19. Wireless Inclinometer Calibration System

    NASA Technical Reports Server (NTRS)

    2008-01-01

    A special system was fabricated to properly calibrate the wireless inclinometer, a new device that will measure the Orbiter s hang angle. The wireless inclinometer has a unique design and method of attachment to the Orbiter that will improve the accuracy of the measurements, as well as the safety and ease of the operation. The system properly calibrates the four attached inclinometers, in both the horizontal and vertical axes, without needing to remove any of the component parts. The Wireless Inclinometer Calibration System combines (1) a calibration fixture that emulates the point of attachment to the Orbiter in both the horizontal and vertical axes and the measurement surfaces, (2) an application-specific software program that accepts calibration data such as dates, zero functions, or offsets and tables, and (3) a wireless interface module that enables the wireless inclinometer to communicate with a calibration PC.

  20. Communications interface for wireless communications headset

    NASA Technical Reports Server (NTRS)

    Seibert, Marc A. (Inventor); Culotta, Jr., Anthony Joseph (Inventor)

    2004-01-01

    A universal interface adapter circuit interfaces, for example, a wireless communications headset with any type of communications system, including those that require push-to-talk (PTT) signaling. The interface adapter is comprised of several main components, including an RF signaling receiver, a microcontroller and associated circuitry for decoding and processing the received signals, and programmable impedance matching and line interfacing circuitry for interfacing a wireless communications headset system base to a communications system. A signaling transmitter, which is preferably portable (e.g., handheld), is employed by the wireless headset user to send signals to the signaling receiver. In an embodiment of the invention directed specifically to push-to-talk (PTT) signaling, the wireless headset user presses a button on the signaling transmitter when they wish to speak. This sends a signal to the microcontroller which decodes the signal and recognizes the signal as being a PTT request. In response, the microcontroller generates a control signal that closes a switch to complete a voice connection between the headset system base and the communications system so that the user can communicate with the communications system. With this arrangement, the wireless headset can be interfaced to any communications system that requires PTT signaling, without modification of the headset device. In addition, the interface adapter can also be configured to respond to or deliver any other types of signals, such as dual-tone-multiple-frequency (DTMF) tones, and on/off hook signals. The present invention is also scalable, and permits multiple wireless users to operate independently in the same environment through use of a plurality of the interface adapters.

  1. Wireless quantified reflex device

    NASA Astrophysics Data System (ADS)

    Lemoyne, Robert Charles

    The deep tendon reflex is a fundamental aspect of a neurological examination. The two major parameters of the tendon reflex are response and latency, which are presently evaluated qualitatively during a neurological examination. The reflex loop is capable of providing insight for the status and therapy response of both upper and lower motor neuron syndromes. Attempts have been made to ascertain reflex response and latency, however these systems are relatively complex, resource intensive, with issues of consistent and reliable accuracy. The solution presented is a wireless quantified reflex device using tandem three dimensional wireless accelerometers to obtain response based on acceleration waveform amplitude and latency derived from temporal acceleration waveform disparity. Three specific aims have been established for the proposed wireless quantified reflex device: 1. Demonstrate the wireless quantified reflex device is reliably capable of ascertaining quantified reflex response and latency using a quantified input. 2. Evaluate the precision of the device using an artificial reflex system. 3.Conduct a longitudinal study respective of subjects with healthy patellar tendon reflexes, using the wireless quantified reflex evaluation device to obtain quantified reflex response and latency. Aim 1 has led to the steady evolution of the wireless quantified reflex device from a singular two dimensional wireless accelerometer capable of measuring reflex response to a tandem three dimensional wireless accelerometer capable of reliably measuring reflex response and latency. The hypothesis for aim 1 is that a reflex quantification device can be established for reliably measuring reflex response and latency for the patellar tendon reflex, comprised of an integrated system of wireless three dimensional MEMS accelerometers. Aim 2 further emphasized the reliability of the wireless quantified reflex device by evaluating an artificial reflex system. The hypothesis for aim 2 is that

  2. A wireless laser displacement sensor node for structural health monitoring.

    PubMed

    Park, Hyo Seon; Kim, Jong Moon; Choi, Se Woon; Kim, Yousok

    2013-09-30

    This study describes a wireless laser displacement sensor node that measures displacement as a representative damage index for structural health monitoring (SHM). The proposed measurement system consists of a laser displacement sensor (LDS) and a customized wireless sensor node. Wireless communication is enabled by a sensor node that consists of a sensor module, a code division multiple access (CDMA) communication module, a processor, and a power module. An LDS with a long measurement distance is chosen to increase field applicability. For a wireless sensor node driven by a battery, we use a power control module with a low-power processor, which facilitates switching between the sleep and active modes, thus maximizing the power consumption efficiency during non-measurement and non-transfer periods. The CDMA mode is also used to overcome the limitation of communication distance, which is a challenge for wireless sensor networks and wireless communication. To evaluate the reliability and field applicability of the proposed wireless displacement measurement system, the system is tested onsite to obtain the required vertical displacement measurements during the construction of mega-trusses and an edge truss, which are the primary structural members in a large-scale irregular building currently under construction. The measurement values confirm the validity of the proposed wireless displacement measurement system and its potential for use in safety evaluations of structural elements.

  3. A Wireless Laser Displacement Sensor Node for Structural Health Monitoring

    PubMed Central

    Park, Hyo Seon; Kim, Jong Moon; Choi, Se Woon; Kim, Yousok

    2013-01-01

    This study describes a wireless laser displacement sensor node that measures displacement as a representative damage index for structural health monitoring (SHM). The proposed measurement system consists of a laser displacement sensor (LDS) and a customized wireless sensor node. Wireless communication is enabled by a sensor node that consists of a sensor module, a code division multiple access (CDMA) communication module, a processor, and a power module. An LDS with a long measurement distance is chosen to increase field applicability. For a wireless sensor node driven by a battery, we use a power control module with a low-power processor, which facilitates switching between the sleep and active modes, thus maximizing the power consumption efficiency during non-measurement and non-transfer periods. The CDMA mode is also used to overcome the limitation of communication distance, which is a challenge for wireless sensor networks and wireless communication. To evaluate the reliability and field applicability of the proposed wireless displacement measurement system, the system is tested onsite to obtain the required vertical displacement measurements during the construction of mega-trusses and an edge truss, which are the primary structural members in a large-scale irregular building currently under construction. The measurement values confirm the validity of the proposed wireless displacement measurement system and its potential for use in safety evaluations of structural elements. PMID:24084114

  4. Self-powered wireless disposable sensor for welfare application.

    PubMed

    Douseki, Takakuni; Tanaka, Ami

    2013-01-01

    A self-powered urinary incontinence sensor consisting of a flexible urine-activated battery and a wireless transmitter has been developed as an application for wireless biosensor networks. The flexible urine-activated battery is embedded in a disposal diaper and makes possible both the sensing of urine leakage and self-powered operation. An intermittent power-supply circuit that uses an electric double-layer capacitor (EDLC) with a small internal resistance suppresses the supply voltage drop due to the large internal resistance of the battery. This circuit supplies the power to a wireless transmitter. A 315-MHz-band wireless transmitter performs low-power operation. To verify the effectiveness of the circuit scheme, we fabricated a prototype sensor system. When 80 cc of urine is poured onto the diaper, the battery outputs a voltage of 1 V; and the sensor can transmit an ID signal over a distance of 5 m. PMID:24110024

  5. Development of fast wireless detection system for fixed offshore platform

    NASA Astrophysics Data System (ADS)

    Li, Zhigang; Yu, Yan; Jiao, Dong; Wang, Jie; Li, Zhirui; Ou, Jinping

    2011-04-01

    -performance computation unit, wireless transceiver unit, mobile power unit and embedded data analysis software, can totally control multi-wireless collection nodes, receive and analyze data, parameter identification. Data is transmitted at the 2.4GHz wireless communication channel, every sensing data channel in charge of data transmission is in a stable frequency band, control channel responsible for the control of power parameters is in a public frequency band. The test is initially conducted for the designed system, experimental results show that the system has good application prospects and practical value with fast arrangement, high sampling rate, high resolution, capacity of low frequency detection.

  6. Optical frequency upconversion technique for transmission of wireless MIMO-type signals over optical fiber.

    PubMed

    Shaddad, R Q; Mohammad, A B; Al-Gailani, S A; Al-Hetar, A M

    2014-01-01

    The optical fiber is well adapted to pass multiple wireless signals having different carrier frequencies by using radio-over-fiber (ROF) technique. However, multiple wireless signals which have the same carrier frequency cannot propagate over a single optical fiber, such as wireless multi-input multi-output (MIMO) signals feeding multiple antennas in the fiber wireless (FiWi) system. A novel optical frequency upconversion (OFU) technique is proposed to solve this problem. In this paper, the novel OFU approach is used to transmit three wireless MIMO signals over a 20 km standard single mode fiber (SMF). The OFU technique exploits one optical source to produce multiple wavelengths by delivering it to a LiNbO3 external optical modulator. The wireless MIMO signals are then modulated by LiNbO3 optical intensity modulators separately using the generated optical carriers from the OFU process. These modulators use the optical single-sideband with carrier (OSSB+C) modulation scheme to optimize the system performance against the fiber dispersion effect. Each wireless MIMO signal is with a 2.4 GHz or 5 GHz carrier frequency, 1 Gb/s data rate, and 16-quadrature amplitude modulation (QAM). The crosstalk between the wireless MIMO signals is highly suppressed, since each wireless MIMO signal is carried on a specific optical wavelength.

  7. Optical Frequency Upconversion Technique for Transmission of Wireless MIMO-Type Signals over Optical Fiber

    PubMed Central

    Shaddad, R. Q.; Mohammad, A. B.; Al-Gailani, S. A.; Al-Hetar, A. M.

    2014-01-01

    The optical fiber is well adapted to pass multiple wireless signals having different carrier frequencies by using radio-over-fiber (ROF) technique. However, multiple wireless signals which have the same carrier frequency cannot propagate over a single optical fiber, such as wireless multi-input multi-output (MIMO) signals feeding multiple antennas in the fiber wireless (FiWi) system. A novel optical frequency upconversion (OFU) technique is proposed to solve this problem. In this paper, the novel OFU approach is used to transmit three wireless MIMO signals over a 20 km standard single mode fiber (SMF). The OFU technique exploits one optical source to produce multiple wavelengths by delivering it to a LiNbO3 external optical modulator. The wireless MIMO signals are then modulated by LiNbO3 optical intensity modulators separately using the generated optical carriers from the OFU process. These modulators use the optical single-sideband with carrier (OSSB+C) modulation scheme to optimize the system performance against the fiber dispersion effect. Each wireless MIMO signal is with a 2.4 GHz or 5 GHz carrier frequency, 1 Gb/s data rate, and 16-quadrature amplitude modulation (QAM). The crosstalk between the wireless MIMO signals is highly suppressed, since each wireless MIMO signal is carried on a specific optical wavelength. PMID:24772009

  8. Development and experimental validation of downlink multiuser MIMO-OFDM in gigabit wireless LAN systems

    NASA Astrophysics Data System (ADS)

    Ishihara, Koichi; Asai, Yusuke; Kudo, Riichi; Ichikawa, Takeo; Takatori, Yasushi; Mizoguchi, Masato

    2013-12-01

    Multiuser multiple-input multiple-output (MU-MIMO) has been proposed as a means to improve spectrum efficiency for various future wireless communication systems. This paper reports indoor experimental results obtained for a newly developed and implemented downlink (DL) MU-MIMO orthogonal frequency division multiplexing (OFDM) transceiver for gigabit wireless local area network systems in the microwave band. In the transceiver, the channel state information (CSI) is estimated at each user and fed back to an access point (AP) on a real-time basis. At the AP, the estimated CSI is used to calculate the transmit beamforming weight for DL MU-MIMO transmission. This paper also proposes a recursive inverse matrix computation scheme for computing the transmit weight in real time. Experiments with the developed transceiver demonstrate its feasibility in a number of indoor scenarios. The experimental results clarify that DL MU-MIMO-OFDM transmission can achieve a 972-Mbit/s transmission data rate with simple digital signal processing of single-antenna users in an indoor environment.

  9. Wireless Sensor Networks: Monitoring and Control

    SciTech Connect

    Hastbacka, Mildred; Ponoum, Ratcharit; Bouza, Antonio

    2013-05-31

    The article discusses wireless sensor technologies for building energy monitoring and control. This article, also, addresses wireless sensor networks as well as benefits and challenges of using wireless sensors. The energy savings and market potential of wireless sensors are reviewed.

  10. Gastric Banding

    MedlinePlus

    ... gastric banding before deciding to have the procedure. Advertisements for a device or procedure may not include ... feeds Follow FDA on Twitter Follow FDA on Facebook View FDA videos on YouTube View FDA photos ...

  11. Wireless Networks: New Meaning to Ubiquitous Computing.

    ERIC Educational Resources Information Center

    Drew, Wilfred, Jr.

    2003-01-01

    Discusses the use of wireless technology in academic libraries. Topics include wireless networks; standards (IEEE 802.11); wired versus wireless; why libraries implement wireless technology; wireless local area networks (WLANs); WLAN security; examples of wireless use at Indiana State University and Morrisville College (New York); and useful…

  12. Massive Access Control Aided by Knowledge-Extraction for Co-Existing Periodic and Random Services over Wireless Clinical Networks.

    PubMed

    Du, Qinghe; Zhao, Weidong; Li, Weimin; Zhang, Xuelin; Sun, Bo; Song, Houbing; Ren, Pinyi; Sun, Li; Wang, Yichen

    2016-07-01

    The prosperity of e-health is boosted by fast development of medical devices with wireless communications capability such as wearable devices, tiny sensors, monitoring equipments, etc., which are randomly distributed in clinic environments. The drastically-increasing population of such devices imposes new challenges on the limited wireless resources. To relieve this problem, key knowledge needs to be extracted from massive connection attempts dispersed in the air towards efficient access control. In this paper, a hybrid periodic-random massive access (HPRMA) scheme for wireless clinical networks employing ultra-narrow band (UNB) techniques is proposed. In particular, the proposed scheme towards accommodating a large population of devices include the following new features. On one hand, it can dynamically adjust the resource allocated for coexisting periodic and random services based on the traffic load learned from signal collision status. On the other hand, the resource allocation within periodic services is thoroughly designed to simultaneously align with the timing requests of differentiated services. Abundant simulation results are also presented to demonstrate the superiority of the proposed HPRMA scheme over baseline schemes including time-division multiple access (TDMA) and random access approach, in terms of channel utilization efficiency, packet drop ratio, etc., for the support of massive devices' services.

  13. Routing and Scheduling Algorithms for WirelessHARTNetworks: A Survey.

    PubMed

    Nobre, Marcelo; Silva, Ivanovitch; Guedes, Luiz Affonso

    2015-01-01

    Wireless communication is a trend nowadays for the industrial environment. A number of different technologies have emerged as solutions satisfying strict industrial requirements (e.g., WirelessHART, ISA100.11a, WIA-PA). As the industrial environment presents a vast range of applications, adopting an adequate solution for each case is vital to obtain good performance of the system. In this context, the routing and scheduling schemes associated with these technologies have a direct impact on important features, like latency and energy consumption. This situation has led to the development of a vast number of routing and scheduling schemes. In the present paper, we focus on the WirelessHART technology, emphasizing its most important routing and scheduling aspects in order to guide both end users and the developers of new algorithms. Furthermore, we provide a detailed literature review of the newest routing and scheduling techniques forWirelessHART, discussing each of their features. These routing algorithms have been evaluated in terms of their objectives, metrics, the usage of theWirelessHART structures and validation method. In addition, the scheduling algorithms were also evaluated by metrics, validation, objectives and, in addition, by multiple superframe support, as well as by the redundancy method used. Moreover, this paper briefly presents some insights into the main WirelessHART simulation modules available, in order to provide viable test platforms for the routing and scheduling algorithms. Finally, some open issues in WirelessHART routing and scheduling algorithms are discussed. PMID:25919371

  14. Routing and Scheduling Algorithms for WirelessHARTNetworks: A Survey.

    PubMed

    Nobre, Marcelo; Silva, Ivanovitch; Guedes, Luiz Affonso

    2015-01-01

    Wireless communication is a trend nowadays for the industrial environment. A number of different technologies have emerged as solutions satisfying strict industrial requirements (e.g., WirelessHART, ISA100.11a, WIA-PA). As the industrial environment presents a vast range of applications, adopting an adequate solution for each case is vital to obtain good performance of the system. In this context, the routing and scheduling schemes associated with these technologies have a direct impact on important features, like latency and energy consumption. This situation has led to the development of a vast number of routing and scheduling schemes. In the present paper, we focus on the WirelessHART technology, emphasizing its most important routing and scheduling aspects in order to guide both end users and the developers of new algorithms. Furthermore, we provide a detailed literature review of the newest routing and scheduling techniques forWirelessHART, discussing each of their features. These routing algorithms have been evaluated in terms of their objectives, metrics, the usage of theWirelessHART structures and validation method. In addition, the scheduling algorithms were also evaluated by metrics, validation, objectives and, in addition, by multiple superframe support, as well as by the redundancy method used. Moreover, this paper briefly presents some insights into the main WirelessHART simulation modules available, in order to provide viable test platforms for the routing and scheduling algorithms. Finally, some open issues in WirelessHART routing and scheduling algorithms are discussed.

  15. A Wireless World: Charles County Public Schools Makes Wireless Universal

    ERIC Educational Resources Information Center

    Hoffman, Richard

    2007-01-01

    Wireless connectivity in schools is all the rage, and many school systems have at least gotten their feet wet with a wireless lab or a few portable laptop carts. But Bijaya Devkota, the chief information officer of Charles County Public Schools, has done what many school systems only dream of--implemented universal wireless access throughout his…

  16. A 350-nm-band GaN/AlGaN multiple-quantum-well laser diode on bulk GaN

    SciTech Connect

    Aoki, Yuta Kuwabara, Masakazu; Yamashita, Yoji; Takagi, Yasufumi; Sugiyama, Atsushi; Yoshida, Harumasa

    2015-10-12

    We have demonstrated the pulsed operation of a 350-nm-band ultraviolet laser diode with a vertical current path. The laser structure was grown on a (0001)-face bulk GaN substrate. The lasing wavelength was 356.6 nm and the peak output power reached to 10 mW from the one side of uncoated facets under pulsed current operation with a pulse duration of 10 ns and a repetition frequency of 5 kHz at room temperature. The GaN substrate is expected to provide a cleaved facet configuration leading to an excellent far-field pattern as well as an advantageous thermal management solution of the devices relative to sapphire substrates. The far-field pattern of actual device on GaN substrate has been improved dramatically compared with distorted one on that of sapphire substrates.

  17. Design of an HF-Band RFID System with Multiple Readers and Passive Tags for Indoor Mobile Robot Self-Localization.

    PubMed

    Mi, Jian; Takahashi, Yasutake

    2016-01-01

    Radio frequency identification (RFID) technology has already been explored for efficient self-localization of indoor mobile robots. A mobile robot equipped with RFID readers detects passive RFID tags installed on the floor in order to locate itself. The Monte-Carlo localization (MCL) method enables the localization of a mobile robot equipped with an RFID system with reasonable accuracy, sufficient robustness and low computational cost. The arrangements of RFID readers and tags and the size of antennas are important design parameters for realizing accurate and robust self-localization using a low-cost RFID system. The design of a likelihood model of RFID tag detection is also crucial for the accurate self-localization. This paper presents a novel design and arrangement of RFID readers and tags for indoor mobile robot self-localization. First, by considering small-sized and large-sized antennas of an RFID reader, we show how the design of the likelihood model affects the accuracy of self-localization. We also design a novel likelihood model by taking into consideration the characteristics of the communication range of an RFID system with a large antenna. Second, we propose a novel arrangement of RFID tags with eight RFID readers, which results in the RFID system configuration requiring much fewer readers and tags while retaining reasonable accuracy of self-localization. We verify the performances of MCL-based self-localization realized using the high-frequency (HF)-band RFID system with eight RFID readers and a lower density of RFID tags installed on the floor based on MCL in simulated and real environments. The results of simulations and real environment experiments demonstrate that our proposed low-cost HF-band RFID system realizes accurate and robust self-localization of an indoor mobile robot. PMID:27483279

  18. Design of an HF-Band RFID System with Multiple Readers and Passive Tags for Indoor Mobile Robot Self-Localization.

    PubMed

    Mi, Jian; Takahashi, Yasutake

    2016-01-01

    Radio frequency identification (RFID) technology has already been explored for efficient self-localization of indoor mobile robots. A mobile robot equipped with RFID readers detects passive RFID tags installed on the floor in order to locate itself. The Monte-Carlo localization (MCL) method enables the localization of a mobile robot equipped with an RFID system with reasonable accuracy, sufficient robustness and low computational cost. The arrangements of RFID readers and tags and the size of antennas are important design parameters for realizing accurate and robust self-localization using a low-cost RFID system. The design of a likelihood model of RFID tag detection is also crucial for the accurate self-localization. This paper presents a novel design and arrangement of RFID readers and tags for indoor mobile robot self-localization. First, by considering small-sized and large-sized antennas of an RFID reader, we show how the design of the likelihood model affects the accuracy of self-localization. We also design a novel likelihood model by taking into consideration the characteristics of the communication range of an RFID system with a large antenna. Second, we propose a novel arrangement of RFID tags with eight RFID readers, which results in the RFID system configuration requiring much fewer readers and tags while retaining reasonable accuracy of self-localization. We verify the performances of MCL-based self-localization realized using the high-frequency (HF)-band RFID system with eight RFID readers and a lower density of RFID tags installed on the floor based on MCL in simulated and real environments. The results of simulations and real environment experiments demonstrate that our proposed low-cost HF-band RFID system realizes accurate and robust self-localization of an indoor mobile robot.

  19. Design of an HF-Band RFID System with Multiple Readers and Passive Tags for Indoor Mobile Robot Self-Localization

    PubMed Central

    Mi, Jian; Takahashi, Yasutake

    2016-01-01

    Radio frequency identification (RFID) technology has already been explored for efficient self-localization of indoor mobile robots. A mobile robot equipped with RFID readers detects passive RFID tags installed on the floor in order to locate itself. The Monte-Carlo localization (MCL) method enables the localization of a mobile robot equipped with an RFID system with reasonable accuracy, sufficient robustness and low computational cost. The arrangements of RFID readers and tags and the size of antennas are important design parameters for realizing accurate and robust self-localization using a low-cost RFID system. The design of a likelihood model of RFID tag detection is also crucial for the accurate self-localization. This paper presents a novel design and arrangement of RFID readers and tags for indoor mobile robot self-localization. First, by considering small-sized and large-sized antennas of an RFID reader, we show how the design of the likelihood model affects the accuracy of self-localization. We also design a novel likelihood model by taking into consideration the characteristics of the communication range of an RFID system with a large antenna. Second, we propose a novel arrangement of RFID tags with eight RFID readers, which results in the RFID system configuration requiring much fewer readers and tags while retaining reasonable accuracy of self-localization. We verify the performances of MCL-based self-localization realized using the high-frequency (HF)-band RFID system with eight RFID readers and a lower density of RFID tags installed on the floor based on MCL in simulated and real environments. The results of simulations and real environment experiments demonstrate that our proposed low-cost HF-band RFID system realizes accurate and robust self-localization of an indoor mobile robot. PMID:27483279

  20. Terahertz (THz) Wireless Systems for Space Applications

    NASA Technical Reports Server (NTRS)

    Hwu, Shian U.; deSilva, Kanishka B.; Jih, Cindy T.

    2013-01-01

    NASA has been leading the Terahertz (THz) technology development for the sensors and instruments in astronomy in the past 20 years. THz technologies are expanding into much broader applications in recent years. Due to the vast available multiple gigahertz (GHz) broad bandwidths, THz radios offer the possibility for wireless transmission of high data rates. Multi-Gigabits per second (MGbps) broadband wireless access based on THz waves are closer to reality. The THz signal high atmosphere attenuation could significantly decrease the communication ranges and transmittable data rates for the ground systems. Contrary to the THz applications on the ground, the space applications in the atmosphere free environment do not suffer the atmosphere attenuation. The manufacturing technologies for the THz electronic components are advancing and maturing. There is great potential for the NASA future high data wireless applications in environments with difficult cabling and size/weight constraints. In this study, the THz wireless systems for potential space applications were investigated. The applicability of THz systems for space applications was analyzed. The link analysis indicates that MGbps data rates are achievable with compact sized high gain antennas.

  1. Wireless Data-Acquisition System for Testing Rocket Engines

    NASA Technical Reports Server (NTRS)

    Lin, Chujen; Lonske, Ben; Hou, Yalin; Xu, Yingjiu; Gang, Mei

    2007-01-01

    A prototype wireless data-acquisition system has been developed as a potential replacement for a wired data-acquisition system heretofore used in testing rocket engines. The traditional use of wires to connect sensors, signal-conditioning circuits, and data acquisition circuitry is time-consuming and prone to error, especially when, as is often the case, many sensors are used in a test. The system includes one master and multiple slave nodes. The master node communicates with a computer via an Ethernet connection. The slave nodes are powered by rechargeable batteries and are packaged in weatherproof enclosures. The master unit and each of the slave units are equipped with a time-modulated ultra-wide-band (TMUWB) radio transceiver, which spreads its RF energy over several gigahertz by transmitting extremely low-power and super-narrow pulses. In this prototype system, each slave node can be connected to as many as six sensors: two sensors can be connected directly to analog-to-digital converters (ADCs) in the slave node and four sensors can be connected indirectly to the ADCs via signal conditioners. The maximum sampling rate for streaming data from any given sensor is about 5 kHz. The bandwidth of one channel of the TM-UWB radio communication system is sufficient to accommodate streaming of data from five slave nodes when they are fully loaded with data collected through all possible sensor connections. TM-UWB radios have a much higher spatial capacity than traditional sinusoidal wave-based radios. Hence, this TM-UWB wireless data-acquisition can be scaled to cover denser sensor setups for rocket engine test stands. Another advantage of TM-UWB radios is that it will not interfere with existing wireless transmission. The maximum radio-communication range between the master node and a slave node for this prototype system is about 50 ft (15 m) when the master and slave transceivers are equipped with small dipole antennas. The range can be increased by changing to

  2. Millimeter-Wave Wireless LAN and Its Extension toward 5G Heterogeneous Networks

    NASA Astrophysics Data System (ADS)

    Sakaguchi, Kei; Mohamed, Ehab Mahmoud; Kusano, Hideyuki; Mizukami, Makoto; Miyamoto, Shinichi; Rezagah, Roya E.; Takinami, Koji; Takahashi, Kazuaki; Shirakata, Naganori; Peng, Hailan; Yamamoto, Toshiaki; Nanba, Shinobu

    Millimeter-wave (mmw) frequency bands, especially 60 GHz unlicensed band, are considered as a promising solution for gigabit short range wireless communication systems. IEEE standard 802.11ad, also known as WiGig, is standardized for the usage of the 60 GHz unlicensed band for wireless local area networks (WLANs). By using this mmw WLAN, multi-Gbps rate can be achieved to support bandwidth-intensive multimedia applications. Exhaustive search along with beamforming (BF) is usually used to overcome 60 GHz channel propagation loss and accomplish data transmissions in such mmw WLANs. Because of its short range transmission with a high susceptibility to path blocking, multiple number of mmw access points (APs) should be used to fully cover a typical target environment for future high capacity multi-Gbps WLANs. Therefore, coordination among mmw APs is highly needed to overcome packet collisions resulting from un-coordinated exhaustive search BF and to increase the total capacity of mmw WLANs. In this paper, we firstly give the current status of mmw WLANs with our developed WiGig AP prototype. Then, we highlight the great need for coordinated transmissions among mmw APs as a key enabler for future high capacity mmw WLANs. Two different types of coordinated mmw WLAN architecture are introduced. One is the distributed antenna type architecture to realize centralized coordination, while the other is an autonomous coordination with the assistance of legacy Wi-Fi signaling. Moreover, two heterogeneous network (HetNet) architectures are also introduced to efficiently extend the coordinated mmw WLANs to be used for future 5th Generation (5G) cellular networks.

  3. Use of Time-Frequency Analysis and Neural Networks for Mode Identification in a Wireless Software-Defined Radio Approach

    NASA Astrophysics Data System (ADS)

    Gandetto, Matteo; Guainazzo, Marco; Regazzoni, Carlo S.

    2004-12-01

    The use of time-frequency distributions is proposed as a nonlinear signal processing technique that is combined with a pattern recognition approach to identify superimposed transmission modes in a reconfigurable wireless terminal based on software-defined radio techniques. In particular, a software-defined radio receiver is described aiming at the identification of two coexistent communication modes: frequency hopping code division multiple access and direct sequence code division multiple access. As a case study, two standards, based on the previous modes and operating in the same band (industrial, scientific, and medical), are considered: IEEE WLAN 802.11b (direct sequence) and Bluetooth (frequency hopping). Neural classifiers are used to obtain identification results. A comparison between two different neural classifiers is made in terms of relative error frequency.

  4. 47 CFR 15.216 - Disclosure requirements for wireless microphones and other low power auxiliary stations capable...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... microphones and other low power auxiliary stations capable of operating in the core TV bands. 15.216 Section... wireless microphones and other low power auxiliary stations capable of operating in the core TV bands. (a... capable of operating in the core TV bands (channels 2-51, excluding channel 37) is subject to...

  5. Broadcasting Systems: An Advanced CATV System with Wireless Distribution

    NASA Astrophysics Data System (ADS)

    Tsuzuku, Aiichiro

    2001-12-01

    CATV(Community Antenna TV) has been started as a measure intended to improve the poor reception area since 1955 at the spa of lkaho in Gunma prefecture. Recently CATV has come into the limelight as a multi program distributor and a new transmission media of the broadband Internet. The percentage of household CATV sets is 22% in 2000 in Japan. The wireless distributed CATV system is able to complement the wired system. It is serviceable in where the cable cannot lay, such as the area studded with houses or isolated island. In this paper, an advanced CATV system with wireless distribution is mentioned. The frequency band is the millimeter-wave band, because it has the characteristic of allowing broadband transmission and miniaturization of devices. The link budget of the test system using 60-GHz band is also described.

  6. Wireless Phone Threat Assessment for Aircraft Communication and Navigation Radios

    NASA Technical Reports Server (NTRS)

    Nguyens, T. X.; Koppen, S. V.; Smith, L. J.; Williams, R. A.; Salud, M. T.

    2005-01-01

    Emissions in aircraft communication and navigation bands are measured for the latest generation of wireless phones. The two wireless technologies considered, GSM/GPRS and CDMA2000, are the latest available to general consumers in the U.S. A base-station simulator is used to control the phones. The measurements are conducted using reverberation chambers, and the results are compared against FCC and aircraft installed equipment emission limits. The results are also compared against baseline emissions from laptop computers and personal digital assistant devices that are currently allowed to operate on aircraft.

  7. Generalized rainbows and unfolded glories of oblate drops: organization for multiple internal reflections and extension of cusps into Alexander's dark band.

    PubMed

    Marston, P L; Kaduchak, G

    1994-07-20

    Oblate drops of water can produce caustics where, unlike a simple Airy caustic, more than two rays merge. We extend previous treatments of generalized primary rainbows based on catastrophe optics [Opt. Lett. 10, 588 (1985); Proc. R. Soc. (London) A 438, 397 (1992)] to rays having (p - 1) = 2 to 5 internal reflections. The analysis is for a horizontally illuminated ellipsoid with a vertical symmetry axis. Aspect ratios causing a vanishing of the vertical curvature at the equator for the outgoing wave front are found from generalized ray tracing. In response to infinitesimal deformation, the axial caustic of real glory rays unfolds producing cusps. Laboratory observations with laser illumination demonstrate that cusps resulting from rays with five internal reflections extend into Alexander's dark band when the drop's aspect ratio is near 1.08. The evolution of this p = 6 scattering pattern as cusps meet the quinary rainbow is suggestive of an E(6) catastrophe. For ellipsoids of varying aspect ratio and refractive index N, there is an organizing singularity associated with an exceptionally flat outgoing wave front from spheres with N = p. PMID:20935841

  8. Engineering chiral density waves and topological band structures by multiple-Q superpositions of collinear up-up-down-down orders

    NASA Astrophysics Data System (ADS)

    Hayami, Satoru; Ozawa, Ryo; Motome, Yukitoshi

    2016-07-01

    Magnetic orders characterized by multiple ordering vectors harbor noncollinear and noncoplanar spin textures and can be a source of unusual electronic properties through the spin Berry phase mechanism. We theoretically show that such multiple-Q states are stabilized in itinerant magnets in the form of superpositions of collinear up-up-down-down (UUDD) spin states, which accompany the density waves of vector and scalar chirality. The result is drawn by examining the ground state of the Kondo lattice model with classical localized moments, especially when the Fermi surface is tuned to be partially nested by the symmetry-related commensurate vectors. We unveil the instability toward a double-Q UUDD state with vector chirality density waves on the square lattice and a triple-Q UUDD state with scalar chirality density waves on the triangular lattice, using the perturbative theory and variational calculations. The former double-Q state is also confirmed by large-scale Langevin dynamics simulations. We also show that, for a sufficiently large exchange coupling, the chirality density waves can induce rich nontrivial topology of electronic structures, such as the massless Dirac semimetal, Chern insulator with quantized topological Hall response, and peculiar edge states which depend on the phase of chirality density waves at the edges.

  9. Solving Autonomy Technology Gaps through Wireless Technology and Orion Avionics Architectural Principles

    NASA Astrophysics Data System (ADS)

    Black, Randy; Bai, Haowei; Michalicek, Andrew; Shelton, Blaine; Villela, Mark

    2008-01-01

    Currently, autonomy in space applications is limited by a variety of technology gaps. Innovative application of wireless technology and avionics architectural principles drawn from the Orion crew exploration vehicle provide solutions for several of these gaps. The Vision for Space Exploration envisions extensive use of autonomous systems. Economic realities preclude continuing the level of operator support currently required of autonomous systems in space. In order to decrease the number of operators, more autonomy must be afforded to automated systems. However, certification authorities have been notoriously reluctant to certify autonomous software in the presence of humans or when costly missions may be jeopardized. The Orion avionics architecture, drawn from advanced commercial aircraft avionics, is based upon several architectural principles including partitioning in software. Robust software partitioning provides "brick wall" separation between software applications executing on a single processor, along with controlled data movement between applications. Taking advantage of these attributes, non-deterministic applications can be placed in one partition and a "Safety" application created in a separate partition. This "Safety" partition can track the position of astronauts or critical equipment and prevent any unsafe command from executing. Only the Safety partition need be certified to a human rated level. As a proof-of-concept demonstration, Honeywell has teamed with the Ultra WideBand (UWB) Working Group at NASA Johnson Space Center to provide tracking of humans, autonomous systems, and critical equipment. Using UWB the NASA team can determine positioning to within less than one inch resolution, allowing a Safety partition to halt operation of autonomous systems in the event that an unplanned collision is imminent. Another challenge facing autonomous systems is the coordination of multiple autonomous agents. Current approaches address the issue as one of

  10. MEMS sensors and wireless telemetry for distributed systems

    SciTech Connect

    Britton, C.L. Jr.; Warmack, R.J.; Smith, S.F.

    1998-02-01

    Selectively coated cantilevers are being developed at ORNL for chemical and biological sensing. The sensitivity can exceed that of other electro-mechanical devices as parts-per-trillion detection can be demonstrated for certain species. The authors are now proceeding to develop systems that employ electrically readable microcantilevers in a standard MEMS process and standard CMOS processes. One of their primary areas of interest is chemical sensing for environmental applications. Towards this end, they are presently developing electronic readout of a mercury-sensitive coated cantilever. In order to field arrays of distributed sensors, a wireless network for data reporting is needed. For this, the authors are developing on-chip spread-spectrum encoding and modulation circuitry to improve the robustness and security of sensor data in typical interference- and multipath-impaired environments. They have also provided for a selection of distinct spreading codes to serve groups of sensors in a common environment by the application of code-division multiple-access techniques. Most of the RF circuitry they have designed and fabricated in 0.5 {micro}m CMOS has been tested and verified operational to above 1 GHz. The initial intended operation is for use in the 915 MHz Industrial, Scientific, and Medical (ISM) band. This paper presents measured data on the microcantilever-based mercury detector. They also present design data and measurements of the RF telemetry chip.

  11. Applying an intelligent and automated emissions measurement system to characterize the RF environment for supporting wireless technologies

    SciTech Connect

    Keebler, P. F.; Phipps, K. O.

    2006-07-01

    The use of wireless technologies in commercial and industrial facilities has grown significantly in the past several years. New applications of wireless technologies with increasing frequency and varying radiated power are being developed everyday. Wireless application specialists and end users have already identified several sources of electromagnetic interference (EMI) in these facilities. Interference has been reported between wireless devices and between these devices and other types of electronic equipment either using frequencies in the unlicensed wireless spectrum or equipment that may generate undesired man-made noise in this spectrum. Facilities that are not using the wireless band should verify the spectral quality of that band and the electromagnetic compatibility (EMC) integrity of safety-related power and signal cables before installing wireless technologies. With the introduction of new wireless devices in the same electromagnetic space where analog and digital I and C systems and cables must co-exist, the ability of facility managers to manage their spectra will dictate the degree of interference between wireless devices and other electronic equipment. Because of the unknowns associated with interference with analog and digital I and C systems in the wireless band, nuclear power plants have been slow to introduce wireless technologies in plant areas. With the application of newly developed advanced radiated emissions measurement systems that can record, process, and analyze radiated and conducted emissions in a cost-effective manner, facility managers can more reliably characterize potential locations for wireless technologies, including potential coupling effects with safety-related power and signal cables, with increased confidence that the risks associated with creating an interference can be significantly reduced. This paper will present an effective philosophy already being used in other mission-critical applications for managing EMC, an

  12. Photonic vector signal generation at W-band employing an optical frequency octupling scheme enabled by a single MZM

    NASA Astrophysics Data System (ADS)

    Li, Xinying; Yu, Jianjun; Zhang, Ziran; Xiao, Jiangnan; Chang, Gee-Kung

    2015-08-01

    We propose photonic vector signal generation at millimeter-wave (mm-wave) bands enabled by a single Mach-Zehnder modulator (MZM) and phase-precoding technique, which can realize photonic frequency multiplication of the precoded microwave vector signal used for the drive of the single MZM. We also experimentally demonstrate the generation of quadrature-phase-shift-keying (QPSK) modulated vector signal at W-band adopting photonic frequency octupling (×8) based on our proposed scheme. The MZM is driven by a 12-GHz QPSK modulated precoded vector signal. Up to 4-Gbaud QPSK-modulated electrical vector signal at 96 GHz is generated and then delivered over 3-m wireless transmission distance.

  13. The Wireless Revolution.

    ERIC Educational Resources Information Center

    Olsen, Florence

    2000-01-01

    Reports on the increasing numbers of colleges and universities which are establishing wireless networks to allow student and faculty with laptop computers to connect to the college network and the Internet from anywhere on campus. Discusses the design of these networks, effects of "nomadic" learning environments, design problems, and the declining…

  14. Building the Wireless Campus

    ERIC Educational Resources Information Center

    Gerraughty, James F.; Shanafelt, Michael E.

    2005-01-01

    This prototype is a continuation of a series of wireless prototypes which began in August 2001 and was reported on again in August 2002. This is the final year of this prototype. This continuation allowed Saint Francis University's Center of Excellence for Remote and Medically Under-Served Areas (CERMUSA) to refine the existing WLAN for the Saint…

  15. Insecurity of Wireless Networks

    SciTech Connect

    Sheldon, Frederick T; Weber, John Mark; Yoo, Seong-Moo; Pan, W. David

    2012-01-01

    Wireless is a powerful core technology enabling our global digital infrastructure. Wi-Fi networks are susceptible to attacks on Wired Equivalency Privacy, Wi-Fi Protected Access (WPA), and WPA2. These attack signatures can be profiled into a system that defends against such attacks on the basis of their inherent characteristics. Wi-Fi is the standard protocol for wireless networks used extensively in US critical infrastructures. Since the Wired Equivalency Privacy (WEP) security protocol was broken, the Wi-Fi Protected Access (WPA) protocol has been considered the secure alternative compatible with hardware developed for WEP. However, in November 2008, researchers developed an attack on WPA, allowing forgery of Address Resolution Protocol (ARP) packets. Subsequent enhancements have enabled ARP poisoning, cryptosystem denial of service, and man-in-the-middle attacks. Open source systems and methods (OSSM) have long been used to secure networks against such attacks. This article reviews OSSMs and the results of experimental attacks on WPA. These experiments re-created current attacks in a laboratory setting, recording both wired and wireless traffic. The article discusses methods of intrusion detection and prevention in the context of cyber physical protection of critical Internet infrastructure. The basis for this research is a specialized (and undoubtedly incomplete) taxonomy of Wi-Fi attacks and their adaptations to existing countermeasures and protocol revisions. Ultimately, this article aims to provide a clearer picture of how and why wireless protection protocols and encryption must achieve a more scientific basis for detecting and preventing such attacks.

  16. Wireless Sensors Network (Sensornet)

    NASA Technical Reports Server (NTRS)

    Perotti, J.

    2003-01-01

    The Wireless Sensor Network System presented in this paper provides a flexible reconfigurable architecture that could be used in a broad range of applications. It also provides a sensor network with increased reliability; decreased maintainability costs, and assured data availability by autonomously and automatically reconfiguring to overcome communication interferences.

  17. High Temperature, Wireless Seismometer Sensor for Venus

    NASA Technical Reports Server (NTRS)

    Ponchak, George E.; Scardelletti, Maximilian C.; Taylor, Brandt; Beard, Steve; Meredith, Roger D.; Beheim, Glenn M.; Hunter Gary W.; Kiefer, Walter S.

    2012-01-01

    Space agency mission plans state the need to measure the seismic activity on Venus. Because of the high temperature on Venus (462? C average surface temperature) and the difficulty in placing and wiring multiple sensors using robots, a high temperature, wireless sensor using a wide bandgap semiconductor is an attractive option. This paper presents the description and proof of concept measurements of a high temperature, wireless seismometer sensor for Venus. A variation in inductance of a coil caused by the movement of an aluminum probe held in the coil and attached to a balanced leaf-spring seismometer causes a variation of 700 Hz in the transmitted signal from the oscillator/sensor system at 426? C. This result indicates that the concept may be used on Venus.

  18. Laparoscopic gastric banding

    MedlinePlus

    ... adjustable gastric banding; Bariatric surgery - laparoscopic gastric banding; Obesity - gastric banding; Weight loss - gastric banding ... gastric banding is not a "quick fix" for obesity. It will greatly change your lifestyle. You must ...

  19. Lifting Scheme DWT Implementation in a Wireless Vision Sensor Network

    NASA Astrophysics Data System (ADS)

    Ong, Jia Jan; Ang, L.-M.; Seng, K. P.

    This paper presents the practical implementation of a Wireless Visual Sensor Network (WVSN) with DWT processing on the visual nodes. WVSN consists of visual nodes that capture video and transmit to the base-station without processing. Limitation of network bandwidth restrains the implementation of real time video streaming from remote visual nodes through wireless communication. Three layers of DWT filters are implemented to process the captured image from the camera. With having all the wavelet coefficients produced, it is possible just to transmit the low frequency band coefficients and obtain an approximate image at the base-station. This will reduce the amount of power required in transmission. When necessary, transmitting all the wavelet coefficients will produce the full detail of image, which is similar to the image captured at the visual nodes. The visual node combines the CMOS camera, Xilinx Spartan-3L FPGA and wireless ZigBee® network that uses the Ember EM250 chip.

  20. A Data Gathering Scheme in Wireless Sensor Networks Based on Synchronization of Chaotic Spiking Oscillator Networks

    SciTech Connect

    Nakano, Hidehiro; Utani, Akihide; Miyauchi, Arata; Yamamoto, Hisao

    2011-04-19

    This paper studies chaos-based data gathering scheme in multiple sink wireless sensor networks. In the proposed scheme, each wireless sensor node has a simple chaotic oscillator. The oscillators generate spike signals with chaotic interspike intervals, and are impulsively coupled by the signals via wireless communication. Each wireless sensor node transmits and receives sensor information only in the timing of the couplings. The proposed scheme can exhibit various chaos synchronous phenomena and their breakdown phenomena, and can effectively gather sensor information with the significantly small number of transmissions and receptions compared with the conventional scheme. Also, the proposed scheme can flexibly adapt various wireless sensor networks not only with a single sink node but also with multiple sink nodes. This paper introduces our previous works. Through simulation experiments, we show effectiveness of the proposed scheme and discuss its development potential.

  1. A Data Gathering Scheme in Wireless Sensor Networks Based on Synchronization of Chaotic Spiking Oscillator Networks

    NASA Astrophysics Data System (ADS)

    Nakano, Hidehiro; Utani, Akihide; Miyauchi, Arata; Yamamoto, Hisao

    2011-04-01

    This paper studies chaos-based data gathering scheme in multiple sink wireless sensor networks. In the proposed scheme, each wireless sensor node has a simple chaotic oscillator. The oscillators generate spike signals with chaotic interspike intervals, and are impulsively coupled by the signals via wireless communication. Each wireless sensor node transmits and receives sensor information only in the timing of the couplings. The proposed scheme can exhibit various chaos synchronous phenomena and their breakdown phenomena, and can effectively gather sensor information with the significantly small number of transmissions and receptions compared with the conventional scheme. Also, the proposed scheme can flexibly adapt various wireless sensor networks not only with a single sink node but also with multiple sink nodes. This paper introduces our previous works. Through simulation experiments, we show effectiveness of the proposed scheme and discuss its development potential.

  2. NASA Bluetooth Wireless Communications

    NASA Technical Reports Server (NTRS)

    Miller, Robert D.

    2007-01-01

    NASA has been interested in wireless communications for many years, especially when the crew size of the International Space Station (ISS) was reduced to two members. NASA began a study to find ways to improve crew efficiency to make sure the ISS could be maintained with limited crew capacity and still be a valuable research testbed in Low-Earth Orbit (LEO). Currently the ISS audio system requires astronauts to be tethered to the audio system, specifically a device called the Audio Terminal Unit (ATU). Wireless communications would remove the tether and allow astronauts to freely float from experiment to experiment without having to worry about moving and reconnecting the associated cabling or finding the space equivalent of an extension cord. A wireless communication system would also improve safety and reduce system susceptibility to Electromagnetic Interference (EMI). Safety would be improved because a crewmember could quickly escape a fire while maintaining communications with the ground and other crewmembers at any location. In addition, it would allow the crew to overcome the volume limitations of the ISS ATU. This is especially important to the Portable Breathing Apparatus (PBA). The next generation of space vehicles and habitats also demand wireless attention. Orion will carry up to six crewmembers in a relatively small cabin. Yet, wireless could become a driving factor to reduce launch weight and increase habitable volume. Six crewmembers, each tethered to a panel, could result in a wiring mess even in nominal operations. In addition to Orion, research is being conducted to determine if Bluetooth is appropriate for Lunar Habitat applications.

  3. Presence of CSF oligoclonal bands (OCB) is associated with the HLA-DRB1 genotype in a West Australian multiple sclerosis cohort.

    PubMed

    Wu, Jing-Shan; Qiu, Wei; Castley, Alison; James, Ian; Joseph, Joyce; Christiansen, Frank T; Carroll, William M; Mastaglia, Frank L; Kermode, Allan G

    2010-01-15

    High-resolution HLA-DRB1 genotyping was performed in 97 OCB-positive and 68 OCB-negative cases with demyelinating disease to determine the influence of HLA-DRB1 alleles on the presence of OCB in a West Australian multiple sclerosis (MS) cohort. Carriage of the HLA-DRB1*1501 allele was associated with both OCB-positive and OCB-negative MS compared with controls, but more strongly with the OCB-positive group, and increased the likelihood of having OCB 2.1-fold with evidence of a dominant dose-effect. The HLA-DRB1*0301 allele was negatively correlated with OCB, with all homozygotes OCB-negative, suggesting a possible recessive protective effect of HLA-DRB1*0301. There was no significant correlation between OCB and the DRB1*04 alleles which have been associated with OCB-negative MS in previous Swedish and Japanese studies. Evidence of allelic interactions was found with HLA-DRB1*1501/*1301 heterozygotes having a reduced frequency of OCB and HLA-DRB1*0301/*0401 heterozygotes all being OCB-negative. These findings confirm the strong association between HLA-DRB1*1501 and OCB which has been found in other populations but indicate that the influence of other HLA-DRB1 alleles varies in different populations. Our study is the first to show that HLA-DRB1 allele interactions and dose-effects influence the frequency of OCB. PMID:19879597

  4. Free-space optical wireless links with topology control

    NASA Astrophysics Data System (ADS)

    Milner, Stuart D.; Ho, Tzung-Hsien; Smolyaninov, Igor I.; Trisno, Sugianto; Davis, Christopher C.

    2002-12-01

    The worldwide demand for broadband communications is being met in many places through the use of installed single-mode fiber networks. However, there is still a significant 'first-mile' problem, which seriously limits the availability of broadband Internet access. Free-space optical wireless communication has emerged as a technique of choice for bridging gaps in the existing high data rate communication networks, and as a backbone for rapidly deployable mobile wireless communication infrastructure. Because free space laser communication links can be easily and rapidly redirected, optical wireless networks can be autonomously reconfigured in a multiple-connected topology to provide improved network performance. In this paper we describe research designed to improve the performance of such networks. Using topology control algorithms, we have demonstrated that multiply-connected, rapidly reconfigurable optical wireless networks can provide robust performance, and a high quality of service at high data rates (up to and beyond 1 Gbps). These systems are also very cost-effective. We have designed and tested on the University of Maryland campus a prototype four-node optical wireless network, where each node could be connected to the others via steerable optical wireless links. The design and performance of this network and the topology control is discussed.

  5. Photonics aided ultra-wideband W-band signal generation and air space transmission

    NASA Astrophysics Data System (ADS)

    Li, Xinying; Yu, Jianjun

    2016-02-01

    We achieve several field trial demonstrations of ultra-wideband W-band millimeter-wave (mm-wave) signal generation and its long-distance air space transmission based on some enabling technologies and advanced devices. First, we demonstrated photonics generation and up to 1.7-km wireless delivery of 20-Gb/s polarization division multiplexing quadrature phase shift keying (PDM-QPSK) signal at W-band, adopting both optical and antenna polarization multiplexing. Then, we demonstrated photonics generation and up to 300-m wireless delivery of 80-Gb/s PDM-QPSK signal at W-band, adopting both optical and antenna polarization multiplexing as well as multi-band multiplexing. We also demonstrated photonics generation and up to 100-m wireless delivery of 100-Gb/s QPSK signal at W-band, adopting antenna polarization multiplexing.

  6. Multi-Band-SWIFT

    NASA Astrophysics Data System (ADS)

    Idiyatullin, Djaudat; Corum, Curtis A.; Garwood, Michael

    2015-02-01

    A useful extension to SWIFT (SWeep Imaging with Fourier Transformation) utilizing sidebands of the excitation pulse is introduced. This MRI method, called Multi-Band-SWIFT, achieves much higher bandwidth than standard SWIFT by using multiple segmented excitations (bands) of the field of view. A description of the general idea and variants of the pulse sequence are presented. From simulations and semi-phenomenological theory, estimations of power deposition and signal-to-noise ratio are made. MB-SWIFT and ZTE (zero-TE) sequences are compared based on images of a phantom and human mandible. Multi-Band-SWIFT provides a bridge between SWIFT and ZTE sequences and allows greatly increased excitation and acquisition bandwidths relative to standard SWIFT for the same hardware switching parameters and requires less peak amplitude of the radiofrequency field (or greater flip angle at same peak amplitude) as compared to ZTE. Multi-Band-SWIFT appears to be an attractive extension of SWIFT for certain musculoskeletal and other medical imaging applications, as well as for imaging materials.

  7. A Sensible Approach to Wireless Networking.

    ERIC Educational Resources Information Center

    Ahmed, S. Faruq

    2002-01-01

    Discusses radio frequency (R.F.) wireless technology, including industry standards, range (coverage) and throughput (data rate), wireless compared to wired networks, and considerations before embarking on a large-scale wireless project. (EV)

  8. Wireless Sensor Network Optimization: Multi-Objective Paradigm.

    PubMed

    Iqbal, Muhammad; Naeem, Muhammad; Anpalagan, Alagan; Ahmed, Ashfaq; Azam, Muhammad

    2015-07-20

    Optimization problems relating to wireless sensor network planning, design, deployment and operation often give rise to multi-objective optimization formulations where multiple desirable objectives compete with each other and the decision maker has to select one of the tradeoff solutions. These multiple objectives may or may not conflict with each other. Keeping in view the nature of the application, the sensing scenario and input/output of the problem, the type of optimization problem changes. To address different nature of optimization problems relating to wireless sensor network design, deployment, operation, planing and placement, there exist a plethora of optimization solution types. We review and analyze different desirable objectives to show whether they conflict with each other, support each other or they are design dependent. We also present a generic multi-objective optimization problem relating to wireless sensor network which consists of input variables, required output, objectives and constraints. A list of constraints is also presented to give an overview of different constraints which are considered while formulating the optimization problems in wireless sensor networks. Keeping in view the multi facet coverage of this article relating to multi-objective optimization, this will open up new avenues of research in the area of multi-objective optimization relating to wireless sensor networks.

  9. Wireless Sensor Network Optimization: Multi-Objective Paradigm

    PubMed Central

    Iqbal, Muhammad; Naeem, Muhammad; Anpalagan, Alagan; Ahmed, Ashfaq; Azam, Muhammad

    2015-01-01

    Optimization problems relating to wireless sensor network planning, design, deployment and operation often give rise to multi-objective optimization formulations where multiple desirable objectives compete with each other and the decision maker has to select one of the tradeoff solutions. These multiple objectives may or may not conflict with each other. Keeping in view the nature of the application, the sensing scenario and input/output of the problem, the type of optimization problem changes. To address different nature of optimization problems relating to wireless sensor network design, deployment, operation, planing and placement, there exist a plethora of optimization solution types. We review and analyze different desirable objectives to show whether they conflict with each other, support each other or they are design dependent. We also present a generic multi-objective optimization problem relating to wireless sensor network which consists of input variables, required output, objectives and constraints. A list of constraints is also presented to give an overview of different constraints which are considered while formulating the optimization problems in wireless sensor networks. Keeping in view the multi facet coverage of this article relating to multi-objective optimization, this will open up new avenues of research in the area of multi-objective optimization relating to wireless sensor networks. PMID:26205271

  10. Neural signal sampling via the low power wireless pico system.

    PubMed

    Cieslewski, Grzegorz; Cheney, David; Gugel, Karl; Sanchez, Justin C; Principe, Jose C

    2006-01-01

    This paper presents a powerful new low power wireless system for sampling multiple channels of neural activity based on Texas Instruments MSP430 microprocessors and Nordic Semiconductor's ultra low power high bandwidth RF transmitters and receivers. The system's development process, component selection, features and test methodology are presented. PMID:17946727

  11. [A wireless mobile monitoring system based on bluetooth technology].

    PubMed

    Sun, Shou-jun; Wu, Kai; Wu, Xiao-Ming

    2006-09-01

    This paper presents a wireless mobile monitoring system based on Bluetooth technology. This system realizes the remote mobile monitoring of multiple physiological parameters, and has the characters of easy use, low cost, good reliability and strong capability of anti-jamming.

  12. Passive wireless wall shear stress sensors

    NASA Astrophysics Data System (ADS)

    Sells, Jeremy

    The design and realization of the first ever passive wireless wall shear stress sensors are presented. The sensors are capable of directly measuring shear forces, 4 mPa to 4 Pa, created at the solid-fluid boundary of a flow. To capture the spatially small structures of a turbulent flow, a micromachined, variable-capacitor floating element sensor is designed. Passive wireless capability is achieved with the addition of an inductive coil and interrogating antenna. These sensors will enable characterization of complex flow phenomena. The primary benefit of the system is that the sensors operate without the need of a direct electrical connection. This simplifies installation of the sensors and enables their placement in locations where the rest of the system either will not fit or cannot survive. By using a passive wireless technique, a power source is not required, extending the life of the sensor and simplifying fabrication. The system makes use of frequency separation, allowing one interrogating antenna to query multiple sensors configured as an array simultaneously. Two generations of the wireless sensor are presented. The design, fabrication, packaging, and characterization of two first-generation sensors have dynamic ranges of 37 and 52 dB. Following this work, specific design improvements were identified and integrated into a second-generation sensor design, resulting in an improvement to 62 dB dynamic range and an order of magnitude reduction in parasitic capacitance and humidity sensitivity. Ideas for a third generation are presented, but realization of this design is left for future work.

  13. Bernauer's bands.

    PubMed

    Shtukenberg, Alexander; Gunn, Erica; Gazzano, Massimo; Freudenthal, John; Camp, Eric; Sours, Ryan; Rosseeva, Elena; Kahr, Bart

    2011-06-01

    Ferdinand Bernauer proposed in his monograph, "Gedrillte" Kristalle (1929), that a great number of simple, crystalline substances grow from solution or from the melt as polycrystalline spherulites with helically twisting radii that give rise to distinct bull's-eye patterns of concentric optical bands between crossed polarizers. The idea that many common molecular crystals can be induced to grow as mesoscale helices is a remarkable proposition poorly grounded in theories of polycrystalline pattern formation. Recent reinvestigation of one of the systems Bernauer described revealed that rhythmic precipitation in the absence of helical twisting accounted for modulated optical properties [Gunn, E. et al. J. Am. Chem. Soc. 2006, 128, 14234-14235]. Herein, the Bernauer hypothesis is re-examined in detail for three substances described in "Gedrillte" Kristalle, potassium dichromate, hippuric acid, and tetraphenyl lead, using contemporary methods of analysis not available to Bernauer, including micro-focus X-ray diffraction, electron microscopy, and Mueller matrix imaging polarimetry. Potassium dichromate is shown to fall in the class of rhythmic precipitates of undistorted crystallites, while hippuric acid spherulites are well described as helical fibrils. Tetraphenyl lead spherulites grow by twisting and rhythmic precipitation. The behavior of tetraphenyl lead is likely typical of many substances in "Gedrillte" Kristalle. Rhythmic precipitation and helical twisting often coexist, complicating optical analyses and presenting Bernauer with difficulties in the characterization and classification of the objects of his interest.

  14. FPGA based Smart Wireless MIMO Control System

    NASA Astrophysics Data System (ADS)

    Usman Ali, Syed M.; Hussain, Sajid; Akber Siddiqui, Ali; Arshad, Jawad Ali; Darakhshan, Anjum

    2013-12-01

    In our present work, we have successfully designed, and developed an FPGA based smart wireless MIMO (Multiple Input & Multiple Output) system capable of controlling multiple industrial process parameters such as temperature, pressure, stress and vibration etc. To achieve this task we have used Xilin x Spartan 3E FPGA (Field Programmable Gate Array) instead of conventional microcontrollers. By employing FPGA kit to PC via RF transceivers which has a working range of about 100 meters. The developed smart system is capable of performing the control task assigned to it successfully. We have also provided a provision to our proposed system that can be accessed for monitoring and control through the web and GSM as well. Our proposed system can be equally applied to all the hazardous and rugged industrial environments where a conventional system cannot work effectively.

  15. Channel Characterization and Robust Tracking for Diversity Reception over Time-Variant Off-Body Wireless Communication Channels

    NASA Astrophysics Data System (ADS)

    Van Torre, Patrick; Vallozzi, Luigi; Rogier, Hendrik; Moeneclaey, Marc; Verhaevert, Jo

    2010-12-01

    In the 2.45 GHz band, indoor wireless off-body data communication by a moving person can be problematic due to time-variant signal fading and the consequent variation in channel parameters. Off-body communication specifically suffers from the combined effects of fading, shadowing, and path loss due to time-variant multipath propagation in combination with shadowing by the human body. Measurements are performed to analyze the autocorrelation, coherence time, and power spectral density for a person equipped with a wearable receive system moving at different speeds for different configurations and antenna positions. Diversity reception with multiple textile antennas integrated in the clothing provides a means of improving the reliability of the link. For the dynamic channel estimation, a scheme using hard decision feedback after MRC with adaptive low-pass filtering is demonstrated to be successful in providing robust data detection for long data bursts, in the presence of dramatic channel variation.

  16. NASA Fuel Tank Wireless Power and Signal Study

    NASA Technical Reports Server (NTRS)

    Merrill, Garrick

    2015-01-01

    Hydro Technologies has developed a custom electronics and mechanical framework for interfacing with off-the-shelf sensors to achieve through barrier sensing solutions. The core project technology relies on Hydro Technologies Wireless Power and Signal Interface (Wi psi) System for transmitting data and power wirelessly using magnetic fields. To accomplish this, Wi psi uses a multi-frequency local magnetic field to produce magnetic fields capable of carrying data and power through almost any material such as metals, seawater, concrete, and air. It will also work through layers of multiple materials.

  17. Energy storage management system with distributed wireless sensors

    SciTech Connect

    Farmer, Joseph C.; Bandhauer, Todd M.

    2015-12-08

    An energy storage system having a multiple different types of energy storage and conversion devices. Each device is equipped with one or more sensors and RFID tags to communicate sensor information wirelessly to a central electronic management system, which is used to control the operation of each device. Each device can have multiple RFID tags and sensor types. Several energy storage and conversion devices can be combined.

  18. 47 CFR 27.1301 - Designated entities in the 600 MHz band.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Designated entities in the 600 MHz band. 27.1301 Section 27.1301 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 600 MHz Band § 27.1301 Designated entities in...

  19. Wireless networking for international safeguards.

    SciTech Connect

    Smartt, Heidi Anne; Caskey, Susan Adele

    2003-06-01

    Wireless networking using the IEEE 802.11standards is a viable alternative for data communications in safeguards applications. This paper discusses the range of 802.11-based networking applications, along with their advantages and disadvantages. For maximum performance, safety, and security, Wireless networking should be implemented only after a comprehensive site survey has determined detailed requirements, hazards, and threats.

  20. Unpowered wireless ultrasound tomography system

    NASA Astrophysics Data System (ADS)

    Zahedi, Farshad; Huang, Haiying

    2016-04-01

    In this paper, an unpowered wireless ultrasound tomography system is presented. The system consists of two subsystems; the wireless interrogation unit (WIU) and three wireless nodes installed on the structure. Each node is designed to work in generation and sensing modes, but operates at a specific microwave frequency. Wireless transmission of the ultrasound signals between the WIU and the wireless nodes is achieved by converting ultrasound signals to microwave signals and vice versa, using a microwave carrier signal. In the generation mode, both a carrier signal and an ultrasound modulated microwave signal are transmitted to the sensor nodes. Only the node whose operating frequency matches the carrier signal will receive these signals and demodulate them to recover the original ultrasound signal. In the sensing mode, a microwave carrier signal with two different frequency components matching the operating frequencies of the sensor nodes is broadcasted by the WIU. The sensor nodes, in turn, receive the corresponding carrier signals, modulate it with the ultrasound sensing signal, and wirelessly transmit the modulated signal back to the WIU. The demodulation of the sensing signals is performed in the WIU using a digital signal processing. Implementing a software receiver significantly reduces the complexity and the cost of the WIU. A wireless ultrasound tomography system is realized by interchanging the carrier frequencies so that the wireless transducers can take turn to serve as the actuator and sensors.

  1. Launching a Wireless Laptop Program

    ERIC Educational Resources Information Center

    Grignano, Domenic

    2007-01-01

    In this article, the author, as a technology director for East Rock Magnet School in New Haven, Connecticut, a federal government test site for laptop learning, shares his secrets to a successful implementation of a wireless laptop program: (1) Build a wireless foundation; (2) Do not choose the cheapest model just because of budget; (3) A sturdy…

  2. System and method for merging clusters of wireless nodes in a wireless network

    DOEpatents

    Budampati, Ramakrishna S.; Gonia, Patrick S.; Kolavennu, Soumitri N.; Mahasenan, Arun V.

    2012-05-29

    A system includes a first cluster having multiple first wireless nodes. One first node is configured to act as a first cluster master, and other first nodes are configured to receive time synchronization information provided by the first cluster master. The system also includes a second cluster having one or more second wireless nodes. One second node is configured to act as a second cluster master, and any other second nodes configured to receive time synchronization information provided by the second cluster master. The system further includes a manager configured to merge the clusters into a combined cluster. One of the nodes is configured to act as a single cluster master for the combined cluster, and the other nodes are configured to receive time synchronization information provided by the single cluster master.

  3. Micromechanics of shear banding

    SciTech Connect

    Gilman, J.J.

    1992-08-01

    Shear-banding is one of many instabilities observed during the plastic flow of solids. It is a consequence of the dislocation mechanism which makes plastic flow fundamentally inhomogeneous, and is exacerbated by local adiabatic heating. Dislocation lines tend to be clustered on sets of neighboring glide planes because they are heterogeneously generated; especially through the Koehler multiple-cross-glide mechanism. Factors that influence their mobilities also play a role. Strain-hardening decreases the mobilities within shear bands thereby tending to spread (delocalize) them. Strain-softening has the inverse effect. This paper reviews the micro-mechanisms of these phenomena. It will be shown that heat production is also a consequence of the heterogeneous nature of the microscopic flow, and that dislocation dipoles play an important role. They are often not directly observable, but their presence may be inferred from changes in thermal conductivity. It is argued that after deformation at low temperatures dipoles are distributed a la Pareto so there are many more small than large ones. Instability at upper yield point, the shapes of shear-band fronts, and mechanism of heat generation are also considered. It is shown that strain-rate acceleration plays a more important role than strain-rate itself in adiabatic instability.

  4. Route Instruction Mechanism for Mobile Users Leveraging Distributed Wireless Resources

    NASA Astrophysics Data System (ADS)

    Kakehi, Takeshi; Shinkuma, Ryoichi; Murase, Tutomu; Motoyoshi, Gen; Yamori, Kyoko; Takahashi, Tatsuro

    The market growths of smart-phones and thin clients have been significantly increasing communication traffic in mobile networks. To handle the increased traffic, network operators should consider how to leverage distributed wireless resources such as distributed spots of wireless local access networks. In this paper, we consider the system where multiple moving users share distributed wireless access points on their traveling routes between their start and goal points and formulate as an optimization problem. Then, we come up with three algorithms as a solution for the problem. The key idea here is ‘longcut route instruction’, in which users are instructed to choose a traveling route where less congested access points are available; even if the moving distance increases, the throughput for users in the system would improve. In this paper, we define the gain function. Moreover, we analyze the basic characteristics of the system using as a simple model as possible.

  5. Semantic Visualization of Wireless Sensor Networks for Elderly Monitoring

    NASA Astrophysics Data System (ADS)

    Stocklöw, Carsten; Kamieth, Felix

    In the area of Ambient Intelligence, Wireless Sensor Networks are commonly used for user monitoring purposes like health monitoring and user localization. Existing work on visualization of wireless sensor networks focuses mainly on displaying individual nodes and logical, graph-based topologies. This way, the relation to the real-world deployment is lost. This paper presents a novel approach for visualization of wireless sensor networks and interaction with complex services on the nodes. The environment is realized as a 3D model, and multiple nodes, that are worn by a single individual, are grouped together to allow an intuitive interface for end users. We describe application examples and show that our approach allows easier access to network information and functionality by comparing it with existing solutions.

  6. Ultrawide band signal analysis in urban environment

    NASA Astrophysics Data System (ADS)

    Schiavone, Guy A.; Palaniappan, Ravishankar; Tracy, Judd; Wahid, Parveen; Dere, Troy P.

    2002-06-01

    Ultra-wide band (UWB) is a relatively new term used to describe a technology that has been known since the 1960's as carrier free, baseband or impulse technology. The basic concept is to develop, transmit and receive an extremely short duration burst of radio frequency energy-typically a few tens of pico seconds to a few nanoseconds in duration. The resultant waveforms are extremely broadband, so much so that it is often difficult to determine an actual RF center frequency- thus the term carrier free. Since UWB waveforms are of such short time duration, they have some rather unique properties. In communications, for example, UWB pulses can be used to provide extremely high data rate performance in multi-user network applications [1]. For radar applications, these same pulses can provide very fine range resolution and precision distance and/or positioning measurement capabilities. These short duration waveforms are relatively immune to multi-path cancellation effects as observed in mobile and in-building environments. As a consequence, UWB systems are particularly well suited for high-speed, mobile wireless applications. As bandwidth is inversely related to pulse duration, the spectral extent of these waveforms can be made quite large. With proper engineering design, the resultant energy densities (i.e., transmitted watts of power per unit hertz of bandwidth) can be quite low. This low energy density translates into a low probability of detection (LPD) RF signature. An LPD signature is of particular interest for military applications (e.g., for covert communications and radar); however, an LPD signature also produces minimal interference to proximity systems and minimal RF health hazards, significant for both military and commercial applications. In this paper we consider the development of a simulation model to calculate ultra-wide band signal propagation characteristics in urban indoor and outdoor environments. The simulation is accomplished using a hybrid model

  7. Wireless Technology in K-12 Education

    ERIC Educational Resources Information Center

    Walery, Darrell

    2004-01-01

    Many schools begin implementing wireless technology slowly by creating wireless "hotspots" on the fly. This is accomplished by putting a wireless access point on a cart along with a set of wireless laptop computers. A teacher can then wheel the cart anywhere in the school that has a network drop, plug the access point in and have an instant…

  8. System and method for progressive band selection for hyperspectral images

    NASA Technical Reports Server (NTRS)

    Fisher, Kevin (Inventor)

    2013-01-01

    Disclosed herein are systems, methods, and non-transitory computer-readable storage media for progressive band selection for hyperspectral images. A system having module configured to control a processor to practice the method calculates a virtual dimensionality of a hyperspectral image having multiple bands to determine a quantity Q of how many bands are needed for a threshold level of information, ranks each band based on a statistical measure, selects Q bands from the multiple bands to generate a subset of bands based on the virtual dimensionality, and generates a reduced image based on the subset of bands. This approach can create reduced datasets of full hyperspectral images tailored for individual applications. The system uses a metric specific to a target application to rank the image bands, and then selects the most useful bands. The number of bands selected can be specified manually or calculated from the hyperspectral image's virtual dimensionality.

  9. Multi-source energy harvesting for wireless SHM systems

    NASA Astrophysics Data System (ADS)

    Choi, Mijin; Farinholt, Kevin M.; Anton, Steven; Lee, Jung-Ryul; Park, Gyuhae

    2013-03-01

    In wireless SHM systems, energy harvesting technology is essential for a reliable long-term energy supply for wireless sensors. Conventional wireless SHM systems using single source energy harvesting (vibration, solar, and etc.) have limitations because it could not be operated adequately without enough ambient energy present. To overcome this obstacle, multi-source energy harvesting which utilizes several ambient energy sources simultaneously is necessary to accumulate enough electrical energy to power wireless embedded sensor nodes. This study proposes a multi-source energy harvesting technique using a MISO (Multiple Input, Single Output) circuit board developed and studied by the authors. For multi-source energy harvesting, piezoelectric bimorph and electro-magnetic energy harvesters are excited at the first natural frequency of each harvester, 126.7 and 12.5 Hz, respectively. Then, generated voltage from each energy harvester is combined using the MISO circuit and then used to charge a 0.1 F capacitor. Combined energy harvesting results presented better performance than that of a single energy source, demonstrating that this multi-source system could be a promising energy harvesting solution for wireless sensing systems.

  10. Wireless Headset Communication System

    NASA Technical Reports Server (NTRS)

    Lau, Wilfred K.; Swanson, Richard; Christensen, Kurt K.

    1995-01-01

    System combines features of pagers, walkie-talkies, and cordless telephones. Wireless headset communication system uses digital modulation on spread spectrum to avoid interference among units. Consists of base station, 4 radio/antenna modules, and as many as 16 remote units with headsets. Base station serves as network controller, audio-mixing network, and interface to such outside services as computers, telephone networks, and other base stations. Developed for use at Kennedy Space Center, system also useful in industrial maintenance, emergency operations, construction, and airport operations. Also, digital capabilities exploited; by adding bar-code readers for use in taking inventories.

  11. Deployable wireless Fresnel lens

    NASA Technical Reports Server (NTRS)

    Kennedy, Timothy F. (Inventor); Fink, Patrick W. (Inventor); Chu, Andrew W. (Inventor); Lin, Gregory Y. (Inventor)

    2013-01-01

    Apparatus and methods for enhancing the gain of a wireless signal are provided. In at least one specific embodiment, the apparatus can include a screen comprised of one or more electrically conductive regions for reflecting electromagnetic radiation and one or more non-conductive regions for permitting electromagnetic radiation therethrough. The one or more electrically conductive regions can be disposed adjacent to at least one of the one or more non-conductive regions. The apparatus can also include a support member disposed about at least a portion of the screen. The screen can be capable of collapsing by twisting the support member in opposite screw senses to form interleaved concentric sections.

  12. Wireless passive radiation sensor

    SciTech Connect

    Pfeifer, Kent B; Rumpf, Arthur N; Yelton, William G; Limmer, Steven J

    2013-12-03

    A novel measurement technique is employed using surface acoustic wave (SAW) devices, passive RF, and radiation-sensitive films to provide a wireless passive radiation sensor that requires no batteries, outside wiring, or regular maintenance. The sensor is small (<1 cm.sup.2), physically robust, and will operate unattended for decades. In addition, the sensor can be insensitive to measurement position and read distance due to a novel self-referencing technique eliminating the need to measure absolute responses that are dependent on RF transmitter location and power.

  13. A wireless MEMS-based inclinometer sensor node for structural health monitoring.

    PubMed

    Ha, Dae Woong; Park, Hyo Seon; Choi, Se Woon; Kim, Yousok

    2013-11-26

    This paper proposes a wireless inclinometer sensor node for structural health monitoring (SHM) that can be applied to civil engineering and building structures subjected to various loadings. The inclinometer used in this study employs a method for calculating the tilt based on the difference between the static acceleration and the acceleration due to gravity, using a micro-electro-mechanical system (MEMS)-based accelerometer. A wireless sensor node was developed through which tilt measurement data are wirelessly transmitted to a monitoring server. This node consists of a slave node that uses a short-distance wireless communication system (RF 2.4 GHz) and a master node that uses a long-distance telecommunication system (code division multiple access-CDMA). The communication distance limitation, which is recognized as an important issue in wireless monitoring systems, has been resolved via these two wireless communication components. The reliability of the proposed wireless inclinometer sensor node was verified experimentally by comparing the values measured by the inclinometer and subsequently transferred to the monitoring server via wired and wireless transfer methods to permit a performance evaluation of the wireless communication sensor nodes. The experimental results indicated that the two systems (wired and wireless transfer systems) yielded almost identical values at a tilt angle greater than 1°, and a uniform difference was observed at a tilt angle less than 0.42° (approximately 0.0032° corresponding to 0.76% of the tilt angle, 0.42°) regardless of the tilt size. This result was deemed to be within the allowable range of measurement error in SHM. Thus, the wireless transfer system proposed in this study was experimentally verified for practical application in a structural health monitoring system.

  14. A Wireless MEMS-Based Inclinometer Sensor Node for Structural Health Monitoring

    PubMed Central

    Ha, Dae Woong; Park, Hyo Seon; Choi, Se Woon; Kim, Yousok

    2013-01-01

    This paper proposes a wireless inclinometer sensor node for structural health monitoring (SHM) that can be applied to civil engineering and building structures subjected to various loadings. The inclinometer used in this study employs a method for calculating the tilt based on the difference between the static acceleration and the acceleration due to gravity, using a micro-electro-mechanical system (MEMS)-based accelerometer. A wireless sensor node was developed through which tilt measurement data are wirelessly transmitted to a monitoring server. This node consists of a slave node that uses a short-distance wireless communication system (RF 2.4 GHz) and a master node that uses a long-distance telecommunication system (code division multiple access—CDMA). The communication distance limitation, which is recognized as an important issue in wireless monitoring systems, has been resolved via these two wireless communication components. The reliability of the proposed wireless inclinometer sensor node was verified experimentally by comparing the values measured by the inclinometer and subsequently transferred to the monitoring server via wired and wireless transfer methods to permit a performance evaluation of the wireless communication sensor nodes. The experimental results indicated that the two systems (wired and wireless transfer systems) yielded almost identical values at a tilt angle greater than 1°, and a uniform difference was observed at a tilt angle less than 0.42° (approximately 0.0032° corresponding to 0.76% of the tilt angle, 0.42°) regardless of the tilt size. This result was deemed to be within the allowable range of measurement error in SHM. Thus, the wireless transfer system proposed in this study was experimentally verified for practical application in a structural health monitoring system. PMID:24287533

  15. Dual-band bandpass filter using composite metamaterial resonator

    NASA Astrophysics Data System (ADS)

    Jin, Yu-Ting; Si, Li-Ming; Zhang, Qing-Le; Wu, Yu-Ming; Lv, Xin

    2016-03-01

    A dual-band bandpass filter at X-band is proposed using composite metamaterial resonator consisting of an outer square closed-ring resonator (SCRR) and two inner electric inductance-capacitance (ELC) resonators. Numerical simulation and microwave measurement reveal that the filter exhibits two passbands centered at 8.76 GHz and 11.04 GHz, with 3 dB bandwidths of 130 MHz and 290 MHz, respectively. The complex dispersion relation of the filter is further derived based on the effective medium theory, where two balanced composite right-/left-handed bands are found, i.e. lines exhibiting two left-handed and two right-handed bands alternating. The proposed filter may find useful in dual-band or multi-band wireless communication systems.

  16. Biomonitoring with Wireless Communications

    SciTech Connect

    Budinger, Thomas F.

    2003-03-01

    This review is divided into three sections: technologies for monitoring physiological parameters; biosensors for chemical assays and wireless communications technologies including image transmissions. Applications range from monitoring high risk patients for heart, respiratory activity and falls to sensing levels of physical activity in military, rescue, and sports personnel. The range of measurements include, heart rate, pulse wave form, respiratory rate, blood oxygen, tissue pCO2, exhaled carbon dioxide and physical activity. Other feasible measurements will employ miniature chemical laboratories on silicon or plastic chips. The measurements can be extended to clinical chemical assays ranging from common blood assays to protein or specialized protein measurements (e.g., troponin, creatine, and cytokines such as TNF and IL6). Though the feasibility of using wireless technology to communicate vital signs has been demonstrated 32 years ago (1) it has been only recently that practical and portable devices and communications net works have become generally available for inexpensive deployment of comfortable and affordable devices and systems.

  17. Household wireless electroencephalogram hat

    NASA Astrophysics Data System (ADS)

    Szu, Harold; Hsu, Charles; Moon, Gyu; Yamakawa, Takeshi; Tran, Binh

    2012-06-01

    We applied Compressive Sensing to design an affordable, convenient Brain Machine Interface (BMI) measuring the high spatial density, and real-time process of Electroencephalogram (EEG) brainwaves by a Smartphone. It is useful for therapeutic and mental health monitoring, learning disability biofeedback, handicap interfaces, and war gaming. Its spec is adequate for a biomedical laboratory, without the cables hanging over the head and tethered to a fixed computer terminal. Our improved the intrinsic signal to noise ratio (SNR) by using the non-uniform placement of the measuring electrodes to create the proximity of measurement to the source effect. We computing a spatiotemporal average the larger magnitude of EEG data centers in 0.3 second taking on tethered laboratory data, using fuzzy logic, and computing the inside brainwave sources, by Independent Component Analysis (ICA). Consequently, we can overlay them together by non-uniform electrode distribution enhancing the signal noise ratio and therefore the degree of sparseness by threshold. We overcame the conflicting requirements between a high spatial electrode density and precise temporal resolution (beyond Event Related Potential (ERP) P300 brainwave at 0.3 sec), and Smartphone wireless bottleneck of spatiotemporal throughput rate. Our main contribution in this paper is the quality and the speed of iterative compressed image recovery algorithm based on a Block Sparse Code (Baranuick et al, IEEE/IT 2008). As a result, we achieved real-time wireless dynamic measurement of EEG brainwaves, matching well with traditionally tethered high density EEG.

  18. Mobile Robot Positioning with 433-MHz Wireless Motes with Varying Transmission Powers and a Particle Filter.

    PubMed

    Canedo-Rodriguez, Adrian; Rodriguez, Jose Manuel; Alvarez-Santos, Victor; Iglesias, Roberto; Regueiro, Carlos V

    2015-01-01

    In wireless positioning systems, the transmitter's power is usually fixed. In this paper, we explore the use of varying transmission powers to increase the performance of a wireless localization system. To this extent, we have designed a robot positioning system based on wireless motes. Our motes use an inexpensive, low-power sub-1-GHz system-on-chip (CC1110) working in the 433-MHz ISM band. Our localization algorithm is based on a particle filter and infers the robot position by: (1) comparing the power received with the expected one; and (2) integrating the robot displacement. We demonstrate that the use of transmitters that vary their transmission power over time improves the performance of the wireless positioning system significantly, with respect to a system that uses fixed power transmitters. This opens the door for applications where the robot can localize itself actively by requesting the transmitters to change their power in real time. PMID:25942641

  19. Mobile Robot Positioning with 433-MHz Wireless Motes with Varying Transmission Powers and a Particle Filter

    PubMed Central

    Canedo-Rodriguez, Adrian; Rodriguez, Jose Manuel; Alvarez-Santos, Victor; Iglesias, Roberto; Regueiro, Carlos V.

    2015-01-01

    In wireless positioning systems, the transmitter's power is usually fixed. In this paper, we explore the use of varying transmission powers to increase the performance of a wireless localization system. To this extent, we have designed a robot positioning system based on wireless motes. Our motes use an inexpensive, low-power sub-1-GHz system-on-chip (CC1110) working in the 433-MHz ISM band. Our localization algorithm is based on a particle filter and infers the robot position by: (1) comparing the power received with the expected one; and (2) integrating the robot displacement. We demonstrate that the use of transmitters that vary their transmission power over time improves the performance of the wireless positioning system significantly, with respect to a system that uses fixed power transmitters. This opens the door for applications where the robot can localize itself actively by requesting the transmitters to change their power in real time. PMID:25942641

  20. A practical monitoring system for the structural safety of mega-trusses using wireless vibrating wire strain gauges.

    PubMed

    Park, Hyo Seon; Lee, Hwan Young; Choi, Se Woon; Kim, Yousok

    2013-12-16

    Sensor technologies have been actively employed in structural health monitoring (SHM) to evaluate structural safety. To provide stable and real-time monitoring, a practical wireless sensor network system (WSNS) based on vibrating wire strain gauges (VWSGs) is proposed and applied to a building under construction. In this WSNS, the data measured from each VWSG are transmitted to the sensor node via a signal line and then transmitted to the master node through a short-range wireless communication module (operating on the Industrial, Scientific, and Medical (ISM) band). The master node also employs a long-range wireless communication module (Code Division Multiple Access-CDMA) to transmit the received data from the sensor node to a server located in a remote area, which enables a manager to examine the measured data in real time without any time or location restrictions. In this study, a total of 48 VWSGs, 14 sensor nodes, and seven master nodes were implemented to measure long-term strain variations of mega-trusses in an irregular large-scale building under construction. Based on strain data collected over a 16-month period, a quantitative evaluation of the construction process was performed to determine the aspects that exhibit the greatest influence on member behavior and to conduct a comparison with numerical simulation results. The effect of temperature stress on the structural elements was also analyzed. From these observations, the feasibility of a long-term WSNS based on VWSGs to evaluate the structural safety of an irregular building under construction was confirmed.

  1. A Practical Monitoring System for the Structural Safety of Mega-Trusses Using Wireless Vibrating Wire Strain Gauges

    PubMed Central

    Park, Hyo Seon; Lee, Hwan Young; Choi, Se Woon; Kim, Yousok

    2013-01-01

    Sensor technologies have been actively employed in structural health monitoring (SHM) to evaluate structural safety. To provide stable and real-time monitoring, a practical wireless sensor network system (WSNS) based on vibrating wire strain gauges (VWSGs) is proposed and applied to a building under construction. In this WSNS, the data measured from each VWSG are transmitted to the sensor node via a signal line and then transmitted to the master node through a short-range wireless communication module (operating on the Industrial, Scientific, and Medical (ISM) band). The master node also employs a long-range wireless communication module (Code Division Multiple Access—CDMA) to transmit the received data from the sensor node to a server located in a remote area, which enables a manager to examine the measured data in real time without any time or location restrictions. In this study, a total of 48 VWSGs, 14 sensor nodes, and seven master nodes were implemented to measure long-term strain variations of mega-trusses in an irregular large-scale building under construction. Based on strain data collected over a 16-month period, a quantitative evaluation of the construction process was performed to determine the aspects that exhibit the greatest influence on member behavior and to conduct a comparison with numerical simulation results. The effect of temperature stress on the structural elements was also analyzed. From these observations, the feasibility of a long-term WSNS based on VWSGs to evaluate the structural safety of an irregular building under construction was confirmed. PMID:24351640

  2. Performance Analysis for LTE Wireless Communication

    NASA Astrophysics Data System (ADS)

    Tholhath, S.; Tiong, T. C.

    2015-04-01

    Long Term Evolution (LTE) is the new upgrade path for carrier with both GSM/UMTS networks and CDMA2000 networks. The LTE is targeting to become the first global mobile phone standard regardless of the different LTE frequencies and bands use in other countries barrier. Adaptive Modulation and Coding (AMC) is used to increase the network capacity or downlink data rates. Various modulation types are discussed such as Quadrature Phase Shift Keying (QPSK) and Quadrature Amplitude Modulation (QAM). Spatial multiplexing techniques for 4×4 MIMO antenna configurations are considered. This paper has outlined various estimation techniques to increase the throughput of the LTE network by simulating the estimation techniques with various parameters in the LTE downlink mode 4 (spatial multiplexing). Three techniques i.e. channel estimation technique, estimation of channel models and MIMO receiver algorithm are simulated to provide the ideal LTE wireless communication system.

  3. Coexistence issues for a 2.4 GHz wireless audio streaming in presence of bluetooth paging and WLAN

    NASA Astrophysics Data System (ADS)

    Pfeiffer, F.; Rashwan, M.; Biebl, E.; Napholz, B.

    2015-11-01

    Nowadays, customers expect to integrate their mobile electronic devices (smartphones and laptops) in a vehicle to form a wireless network. Typically, IEEE 802.11 is used to provide a high-speed wireless local area network (WLAN) and Bluetooth is used for cable replacement applications in a wireless personal area network (PAN). In addition, Daimler uses KLEER as third wireless technology in the unlicensed (UL) 2.4 GHz-ISM-band to transmit full CD-quality digital audio. As Bluetooth, IEEE 802.11 and KLEER are operating in the same frequency band, it has to be ensured that all three technologies can be used simultaneously without interference. In this paper, we focus on the impact of Bluetooth and IEEE 802.11 as interferer in presence of a KLEER audio transmission.

  4. Radio Relays Improve Wireless Products

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Signal Hill, California-based XCOM Wireless Inc. developed radio frequency micromachine (RF MEMS) relays with a Phase II Small Business Innovation Research (SBIR) contract through NASA?s Jet Propulsion Laboratory. In order to improve satellite communication systems, XCOM produced wireless RF MEMS relays and tunable capacitors that use metal-to-metal contact and have the potential to outperform most semiconductor technologies while using less power. These relays are used in high-frequency test equipment and instrumentation, where increased speed can mean significant cost savings. Applications now also include mainstream wireless applications and greatly improved tactical radios.

  5. Wireless Communications in Smart Grid

    NASA Astrophysics Data System (ADS)

    Bojkovic, Zoran; Bakmaz, Bojan

    Communication networks play a crucial role in smart grid, as the intelligence of this complex system is built based on information exchange across the power grid. Wireless communications and networking are among the most economical ways to build the essential part of the scalable communication infrastructure for smart grid. In particular, wireless networks will be deployed widely in the smart grid for automatic meter reading, remote system and customer site monitoring, as well as equipment fault diagnosing. With an increasing interest from both the academic and industrial communities, this chapter systematically investigates recent advances in wireless communication technology for the smart grid.

  6. Wireless device monitoring methods, wireless device monitoring systems, and articles of manufacture

    DOEpatents

    McCown, Steven H.; Derr, Kurt W.; Rohde, Kenneth W.

    2012-05-08

    Wireless device monitoring methods, wireless device monitoring systems, and articles of manufacture are described. According to one embodiment, a wireless device monitoring method includes accessing device configuration information of a wireless device present at a secure area, wherein the device configuration information comprises information regarding a configuration of the wireless device, accessing stored information corresponding to the wireless device, wherein the stored information comprises information regarding the configuration of the wireless device, comparing the device configuration information with the stored information, and indicating the wireless device as one of authorized and unauthorized for presence at the secure area using the comparing.

  7. Ultrasonic wireless health monitoring

    NASA Astrophysics Data System (ADS)

    Petit, Lionel; Lefeuvre, Elie; Guyomar, Daniel; Richard, Claude; Guy, Philippe; Yuse, Kaori; Monnier, Thomas

    2006-03-01

    The integration of autonomous wireless elements in health monitoring network increases the reliability by suppressing power supplies and data transmission wiring. Micro-power piezoelectric generators are an attractive alternative to primary batteries which are limited by a finite amount of energy, a limited capacity retention and a short shelf life (few years). Our goal is to implement such an energy harvesting system for powering a single AWT (Autonomous Wireless Transmitter) using our SSH (Synchronized Switch Harvesting) method. Based on a non linear process of the piezoelement voltage, this SSH method optimizes the energy extraction from the mechanical vibrations. This AWT has two main functions : The generation of an identifier code by RF transmission to the central receiver and the Lamb wave generation for the health monitoring of the host structure. A damage index is derived from the variation between the transmitted wave spectrum and a reference spectrum. The same piezoelements are used for the energy harvesting function and the Lamb wave generation, thus reducing mass and cost. A micro-controller drives the energy balance and synchronizes the functions. Such an autonomous transmitter has been evaluated on a 300x50x2 mm 3 composite cantilever beam. Four 33x11x0.3 mm 3 piezoelements are used for the energy harvesting and for the wave lamb generation. A piezoelectric sensor is placed at the free end of the beam to track the transmitted Lamb wave. In this configuration, the needed energy for the RF emission is 0.1 mJ for a 1 byte-information and the Lamb wave emission requires less than 0.1mJ. The AWT can harvested an energy quantity of approximately 20 mJ (for a 1.5 Mpa lateral stress) with a 470 μF storage capacitor. This corresponds to a power density near to 6mW/cm 3. The experimental AWT energy abilities are presented and the damage detection process is discussed. Finally, some envisaged solutions are introduced for the implementation of the required data

  8. Laparoscopic gastric banding - discharge

    MedlinePlus

    ... laparoscopic gastric banding - discharge; Obesity gastric banding discharge; Weight loss - gastric banding discharge ... as your body gets used to your weight loss and your weight becomes stable. Weight loss may be slower after ...

  9. Wireless Damage Location Sensing System

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E. (Inventor); Taylor, Bryant Douglas (Inventor)

    2012-01-01

    A wireless damage location sensing system uses a geometric-patterned wireless sensor that resonates in the presence of a time-varying magnetic field to generate a harmonic response that will experience a change when the sensor experiences a change in its geometric pattern. The sensing system also includes a magnetic field response recorder for wirelessly transmitting the time-varying magnetic field and for wirelessly detecting the harmonic response. The sensing system compares the actual harmonic response to a plurality of predetermined harmonic responses. Each predetermined harmonic response is associated with a severing of the sensor at a corresponding known location thereof so that a match between the actual harmonic response and one of the predetermined harmonic responses defines the known location of the severing that is associated therewith.

  10. Wireless power transfer system

    DOEpatents

    Wu, Hunter; Sealy, Kylee; Gilchrist, Aaron

    2016-02-23

    A system includes a first stage of an inductive power transfer system with an LCL load resonant converter with a switching section, an LCL tuning circuit, and a primary receiver pad. The IPT system includes a second stage with a secondary receiver pad, a secondary resonant circuit, a secondary rectification circuit, and a secondary decoupling converter. The secondary receiver pad connects to the secondary resonant circuit. The secondary resonant circuit connects to the secondary rectification circuit. The secondary rectification circuit connects to the secondary decoupling converter. The second stage connects to a load. The load includes an energy storage element. The second stage and load are located on a vehicle and the first stage is located at a fixed location. The primary receiver pad wirelessly transfers power to the secondary receiver pad across a gap when the vehicle positions the secondary receiver pad with respect to the primary receiver pad.

  11. Wireless Josephson Junction Arrays

    NASA Astrophysics Data System (ADS)

    Adams, Laura

    2015-03-01

    We report low temperature, microwave transmission measurements on a wireless two- dimensional network of Josephson junction arrays composed of superconductor-insulator -superconductor tunnel junctions. Unlike their biased counterparts, by removing all electrical contacts to the arrays and superfluous microwave components and interconnects in the transmission line, we observe new collective behavior in the transmission spectra. In particular we will show emergent behavior that systematically responds to changes in microwave power at fixed temperature. Likewise we will show the dynamic and collective response of the arrays while tuning the temperature at fixed microwave power. We discuss these spectra in terms of the Berezinskii-Kosterlitz-Thouless phase transition and Shapiro steps. We gratefully acknowledge the support Prof. Steven Anlage at the University of Maryland and Prof. Allen Goldman at the University of Minnesota. Physics and School of Engineering and Applied Sciences.

  12. Wireless sensor network

    NASA Astrophysics Data System (ADS)

    Perotti, Jose M.; Lucena, Angel R.; Mullenix, Pamela A.; Mata, Carlos T.

    2006-05-01

    Current and future requirements of aerospace sensors and transducers demand the design and development of a new family of sensing devices, with emphasis on reduced weight, power consumption, and physical size. This new generation of sensors and transducers will possess a certain degree of intelligence in order to provide the end user with critical data in a more efficient manner. Communication between networks of traditional or next-generation sensors can be accomplished by a Wireless Sensor Network (WSN) developed by NASA's Instrumentation Branch and ASRC Aerospace Corporation at Kennedy Space Center (KSC), consisting of at least one central station and several remote stations and their associated software. The central station is application-dependent and can be implemented on different computer hardware, including industrial, handheld, or PC-104 single-board computers, on a variety of operating systems: embedded Windows, Linux, VxWorks, etc. The central stations and remote stations share a similar radio frequency (RF) core module hardware that is modular in design. The main components of the remote stations are an RF core module, a sensor interface module, batteries, and a power management module. These modules are stackable, and a common bus provides the flexibility to stack other modules for additional memory, increased processing, etc. WSN can automatically reconfigure to an alternate frequency if interference is encountered during operation. In addition, the base station will autonomously search for a remote station that was perceived to be lost, using relay stations and alternate frequencies. Several wireless remote-station types were developed and tested in the laboratory to support different sensing technologies, such as resistive temperature devices, silicon diodes, strain gauges, pressure transducers, and hydrogen leak detectors.

  13. Wireless Power Transfer

    SciTech Connect

    2013-07-22

    Wireless Power Transfer is an innovative approach using magnetic resonance coupling of air core transformers designed for today's growing plug-in electric vehicle market. This technology can provide a convenient, safe and flexible means to charge electric vehicles under stationary and dynamic conditions. Plug-in Electric Vehicles (PEV) are burdened by the need for cable and plug charger, galvanic isolation of the on-board electronics, bulk and cost of this charger and the large energy storage system (ESS) packs needed. With a system where you have to physically plug in there are a number of occasions where the owner could very well forget to charge the vehicle. For stationary applications (like charging of a PHEV at home), ORNL's innovative wireless power transfer technology adds a convenience factor compared to actually plugging in which will mean that the vehicle will have a full charge every morning. Electric vehicle charging must be safe, compact and efficient in order to be convenient for customers. By reconfiguring the transformer and altering the resonance frequency, energy is transferred to the battery with lower energy losses and with fewer demands on the primary circuit by the rest of the transformer system. The ORNL discovery shows that sufficient power for the battery can be transferred from the primary to secondary circuits without significant energy losses if the operating frequency is set at 50% to 95% of the resonance frequency of the circuit. The electrical power is then transmitted to the chargeable battery, which is electrically coupled to the secondary circuit through the air core transformer. Some advantages include: Reduced energy losses during transfer of energy to the battery; A charge potential that is relatively unaffected by up to 25% misalignment of vehicle; and Other receiving components draw less power from the primary circuit. These advantages allow wireless power technology applications to expand at the workplace and beyond as the

  14. Wireless Power Transfer

    ScienceCinema

    None

    2016-07-12

    Wireless Power Transfer is an innovative approach using magnetic resonance coupling of air core transformers designed for today's growing plug-in electric vehicle market. This technology can provide a convenient, safe and flexible means to charge electric vehicles under stationary and dynamic conditions. Plug-in Electric Vehicles (PEV) are burdened by the need for cable and plug charger, galvanic isolation of the on-board electronics, bulk and cost of this charger and the large energy storage system (ESS) packs needed. With a system where you have to physically plug in there are a number of occasions where the owner could very well forget to charge the vehicle. For stationary applications (like charging of a PHEV at home), ORNL's innovative wireless power transfer technology adds a convenience factor compared to actually plugging in which will mean that the vehicle will have a full charge every morning. Electric vehicle charging must be safe, compact and efficient in order to be convenient for customers. By reconfiguring the transformer and altering the resonance frequency, energy is transferred to the battery with lower energy losses and with fewer demands on the primary circuit by the rest of the transformer system. The ORNL discovery shows that sufficient power for the battery can be transferred from the primary to secondary circuits without significant energy losses if the operating frequency is set at 50% to 95% of the resonance frequency of the circuit. The electrical power is then transmitted to the chargeable battery, which is electrically coupled to the secondary circuit through the air core transformer. Some advantages include: Reduced energy losses during transfer of energy to the battery; A charge potential that is relatively unaffected by up to 25% misalignment of vehicle; and Other receiving components draw less power from the primary circuit. These advantages allow wireless power technology applications to expand at the workplace and beyond as the

  15. Wireless Instrumentation Use on Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Sherman, Aaron

    2010-01-01

    This slide presentation reviews the results of a study on the use of wireless instrumentation and sensors on future launch vehicles. The use of wireless technologies would if feasible would allow for fewer wires, and allow for more flexibility. However, it was generally concluded that wireless solutions are not currently ready to replace wired technologies for launch vehicles. The recommendations of the study were to continue to use wired sensors as the primary choice for vehicle instrumentation, and to continue to assess needs and use wireless instrumentation where appropriate. The future work includes support efforts for wireless technologies, and continue to monitor the development of wireless solutions.

  16. Challenges of CAC in Heterogeneous Wireless Cognitive Networks

    NASA Astrophysics Data System (ADS)

    Wang, Jiazheng; Fu, Xiuhua

    Call admission control (CAC) is known as an effective functionality in ensuring the QoS of wireless networks. The vision of next generation wireless networks has led to the development of new call admission control (CAC) algorithms specifically designed for heterogeneous wireless Cognitive networks. However, there will be a number of challenges created by dynamic spectrum access and scheduling techniques associated with the cognitive systems. In this paper for the first time, we recommend that the CAC policies should be distinguished between primary users and secondary users. The classification of different methods of cac policies in cognitive networks contexts is proposed. Although there have been some researches within the umbrella of Joint CAC and cross-layer optimization for wireless networks, the advent of the cognitive networks adds some additional problems. We present the conceptual models for joint CAC and cross-layer optimization respectively. Also, the benefit of Cognition can only be realized fully if application requirements and traffic flow contexts are determined or inferred in order to know what modes of operation and spectrum bands to use at each point in time. The process model of Cognition involved per-flow-based CAC is presented. Because there may be a number of parameters on different levels affecting a CAC decision and the conditions for accepting or rejecting a call must be computed quickly and frequently, simplicity and practicability are particularly important for designing a feasible CAC algorithm. In a word, a more thorough understanding of CAC in heterogeneous wireless cognitive networks may help one to design better CAC algorithms.

  17. Direct band gap silicon allotropes.

    PubMed

    Wang, Qianqian; Xu, Bo; Sun, Jian; Liu, Hanyu; Zhao, Zhisheng; Yu, Dongli; Fan, Changzeng; He, Julong

    2014-07-16

    Elemental silicon has a large impact on the economy of the modern world and is of fundamental importance in the technological field, particularly in solar cell industry. The great demand of society for new clean energy and the shortcomings of the current silicon solar cells are calling for new materials that can make full use of the solar power. In this paper, six metastable allotropes of silicon with direct or quasidirect band gaps of 0.39-1.25 eV are predicted by ab initio calculations at ambient pressure. Five of them possess band gaps within the optimal range for high converting efficiency from solar energy to electric power and also have better optical properties than the Si-I phase. These Si structures with different band gaps could be applied to multiple p-n junction photovoltaic modules.

  18. 60-GHz optical/wireless MIMO system integrated with optical subcarrier multiplexing and 2x2 wireless communication.

    PubMed

    Lin, Chi-Hsiang; Lin, Chun-Ting; Huang, Hou-Tzu; Zeng, Wei-Siang; Chiang, Shou-Chih; Chang, Hsi-Yu

    2015-05-01

    This paper proposes a 2x2 MIMO OFDM Radio-over-Fiber scheme based on optical subcarrier multiplexing and 60-GHz MIMO wireless transmission. We also schematically investigated the principle of optical subcarrier multiplexing, which is based on a dual-parallel Mach-Zehnder modulator (DP-MZM). In our simulation result, combining two MIMO OFDM signals to drive DP-MZM gives rise to the PAPR augmentation of less than 0.4 dB, which mitigates nonlinear distortion. Moreover, we applied a Levin-Campello bit-loading algorithm to compensate for the uneven frequency responses in the V-band. The resulting system achieves OFDM signal rates of 61.5-Gbits/s with BER of 10(-3) over 25-km SMF transmission followed by 3-m wireless transmission.

  19. Come Join the Band

    ERIC Educational Resources Information Center

    Olson, Cathy Applefeld

    2011-01-01

    A growing number of students in Blue Springs, Missouri, are joining the band, drawn by a band director who emphasizes caring and inclusiveness. In the four years since Melissia Goff arrived at Blue Springs High School, the school's extensive band program has swelled. The marching band alone has gone from 100 to 185 participants. Also under Goff's…

  20. Cooperation and information replication in wireless networks.

    PubMed

    Poularakis, Konstantinos; Tassiulas, Leandros

    2016-03-01

    A significant portion of today's network traffic is due to recurring downloads of a few popular contents. It has been observed that replicating the latter in caches installed at network edges-close to users-can drastically reduce network bandwidth usage and improve content access delay. Such caching architectures are gaining increasing interest in recent years as a way of dealing with the explosive traffic growth, fuelled further by the downward slope in storage space price. In this work, we provide an overview of caching with a particular emphasis on emerging network architectures that enable caching at the radio access network. In this context, novel challenges arise due to the broadcast nature of the wireless medium, which allows simultaneously serving multiple users tuned into a multicast stream, and the mobility of the users who may be frequently handed off from one cell tower to another. Existing results indicate that caching at the wireless edge has a great potential in removing bottlenecks on the wired backbone networks. Taking into consideration the schedule of multicast service and mobility profiles is crucial to extract maximum benefit in network performance. PMID:26809574

  1. 75 FR 8400 - In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

    ... COMMISSION In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld Devices... importation, and the sale within the United States after importation of certain wireless communications system server software, wireless handheld devices and battery packs by reason of infringement of certain...

  2. Efficient data communication protocols for wireless networks

    NASA Astrophysics Data System (ADS)

    Zeydan, Engin

    In this dissertation, efficient decentralized algorithms are investigated for cost minimization problems in wireless networks. For wireless sensor networks, we investigate both the reduction in the energy consumption and throughput maximization problems separately using multi-hop data aggregation for correlated data in wireless sensor networks. The proposed algorithms exploit data redundancy using a game theoretic framework. For energy minimization, routes are chosen to minimize the total energy expended by the network using best response dynamics to local data. The cost function used in routing takes into account distance, interference and in-network data aggregation. The proposed energy-efficient correlation-aware routing algorithm significantly reduces the energy consumption in the network and converges in a finite number of steps iteratively. For throughput maximization, we consider both the interference distribution across the network and correlation between forwarded data when establishing routes. Nodes along each route are chosen to minimize the interference impact in their neighborhood and to maximize the in-network data aggregation. The resulting network topology maximizes the global network throughput and the algorithm is guaranteed to converge with a finite number of steps using best response dynamics. For multiple antenna wireless ad-hoc networks, we present distributed cooperative and regret-matching based learning schemes for joint transmit beanformer and power level selection problem for nodes operating in multi-user interference environment. Total network transmit power is minimized while ensuring a constant received signal-to-interference and noise ratio at each receiver. In cooperative and regret-matching based power minimization algorithms, transmit beanformers are selected from a predefined codebook to minimize the total power. By selecting transmit beamformers judiciously and performing power adaptation, the cooperative algorithm is shown to

  3. Routing and Scheduling Algorithms for WirelessHART Networks: A Survey

    PubMed Central

    Nobre, Marcelo; Silva, Ivanovitch; Guedes, Luiz Affonso

    2015-01-01

    Wireless communication is a trend nowadays for the industrial environment. A number of different technologies have emerged as solutions satisfying strict industrial requirements (e.g., WirelessHART, ISA100.11a, WIA-PA). As the industrial environment presents a vast range of applications, adopting an adequate solution for each case is vital to obtain good performance of the system. In this context, the routing and scheduling schemes associated with these technologies have a direct impact on important features, like latency and energy consumption. This situation has led to the development of a vast number of routing and scheduling schemes. In the present paper, we focus on the WirelessHART technology, emphasizing its most important routing and scheduling aspects in order to guide both end users and the developers of new algorithms. Furthermore, we provide a detailed literature review of the newest routing and scheduling techniques for WirelessHART, discussing each of their features. These routing algorithms have been evaluated in terms of their objectives, metrics, the usage of the WirelessHART structures and validation method. In addition, the scheduling algorithms were also evaluated by metrics, validation, objectives and, in addition, by multiple superframe support, as well as by the redundancy method used. Moreover, this paper briefly presents some insights into the main WirelessHART simulation modules available, in order to provide viable test platforms for the routing and scheduling algorithms. Finally, some open issues in WirelessHART routing and scheduling algorithms are discussed. PMID:25919371

  4. Design of multilevel heterogeneous ad-hoc wireless networks with UAVs

    NASA Astrophysics Data System (ADS)

    Gu, Daniel L.; Gerla, Mario; Ly, Henry; Xu, Kaixin; Kong, Jiejun; Hong, Xiaoyan

    2001-10-01

    Multi-Layer Ad Hoc Wireless Networks with UAVs is an ideal infrastructure to establish a rapidly deployable wireless communication system any time any where in the world for military applications. In this paper, we review the research we have done so far for our heterogeneous solution. First of all, we proposed the infrastructure of Multi-level Heterogeneous Ad-Hoc Wireless Network with UAVs. Second, we developed a new MAC layer protocol, Centralized Intelligent Channel Assigned Multiple Access (C-ICAMA), for ground mobile backbone nodes to access UAV. Third, we extended HSR (Hierarchical State Routing) to this Multi-Level Heterogeneous Ad-Hoc Wireless Network. Due to the intrinsic limitations of Extended HSR, we extended the Landmark Ad Hoc Routing (LANMAR) as our forth step. Security is a critical issue for mobile ad-hoc wireless networks, especially for military applications. We developed an embedded distributed security protocol and integrated with this heterogeneous hierarchical ad hoc wireless networks in our fifth step. Therefore, the hierarchical multi-layer approach is the most desirable approach to achieve routing scalability in multi-hop wireless networks.

  5. Communications device identification methods, communications methods, wireless communications readers, wireless communications systems, and articles of manufacture

    DOEpatents

    Steele, Kerry D [Kennewick, WA; Anderson, Gordon A [Benton City, WA; Gilbert, Ronald W [Morgan Hill, CA

    2011-02-01

    Communications device identification methods, communications methods, wireless communications readers, wireless communications systems, and articles of manufacture are described. In one aspect, a communications device identification method includes providing identification information regarding a group of wireless identification devices within a wireless communications range of a reader, using the provided identification information, selecting one of a plurality of different search procedures for identifying unidentified ones of the wireless identification devices within the wireless communications range, and identifying at least some of the unidentified ones of the wireless identification devices using the selected one of the search procedures.

  6. 47 CFR 27.1102 - Designated Entities in the 1710-1755 MHz and 2110-2155 MHz bands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2110-2155 MHz bands. 27.1102 Section 27.1102 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz, 2110-2155... the 1710-1755 MHz and 2110-2155 MHz bands. (a) Eligibility for small business provisions. (1) A...

  7. Mobilize Your instruction Program with Wireless Technology.

    ERIC Educational Resources Information Center

    Mathias, Molly Susan; Heser, Steven

    2002-01-01

    Describes the use of wireless technology for library bibliographic instruction at the Milwaukee Area Technical College. Highlights include a wireless mobile cart that holds laptop computers; faculty support; future plans; and recommendations, including investigating technology infrastructure and marketing. (LRW)

  8. Robust Forecasting for Energy Efficiency of Wireless Multimedia Sensor Networks

    PubMed Central

    Wang, Xue; Ma, Jun-Jie; Ding, Liang; Bi, Dao-Wei

    2007-01-01

    An important criterion of wireless sensor network is the energy efficiency in specified applications. In this wireless multimedia sensor network, the observations are derived from acoustic sensors. Focused on the energy problem of target tracking, this paper proposes a robust forecasting method to enhance the energy efficiency of wireless multimedia sensor networks. Target motion information is acquired by acoustic sensor nodes while a distributed network with honeycomb configuration is constructed. Thereby, target localization is performed by multiple sensor nodes collaboratively through acoustic signal processing. A novel method, combining autoregressive moving average (ARMA) model and radial basis function networks (RBFNs), is exploited to perform robust target position forecasting during target tracking. Then sensor nodes around the target are awakened according to the forecasted target position. With committee decision of sensor nodes, target localization is performed in a distributed manner and the uncertainty of detection is reduced. Moreover, a sensor-to-observer routing approach of the honeycomb mesh network is investigated to solve the data reporting considering the residual energy of sensor nodes. Target localization and forecasting are implemented in experiments. Meanwhile, sensor node awakening and dynamic routing are evaluated. Experimental results verify that energy efficiency of wireless multimedia sensor network is enhanced by the proposed target tracking method.

  9. Wireless data transfer with mm-waves for future tracking detectors

    NASA Astrophysics Data System (ADS)

    Pelikan, D.; Bingefors, N.; Brenner, R.; Dancila, D.; Gustafsson, L.

    2014-11-01

    Wireless data transfer has revolutionized the consumer market for the last decade generating many products equipped with transmitters and receivers for wireless data transfer. Wireless technology opens attractive possibilities for data transfer in future tracking detectors. The reduction of wires and connectors for data links is certainly beneficial both for the material budget and the reliability of the system. An advantage of wireless data transfer is the freedom of routing signals which today is particularly complicated when bringing the data the first 50 cm out of the tracker. With wireless links intelligence can be built into a tracker by introducing communication between tracking layers within a region of interest which would allow the construction of track primitives in real time. The wireless technology used in consumer products is however not suitable for tracker readouts. The low data transfer capacity of current 5 GHz transceivers and the relatively large feature sizes of the components is a disadvantage.Due to the requirement of high data rates in tracking detectors high bandwidth is required. The frequency band around 60 GHz turns out to be a very promising candidate for data transfer in a detector system. The high baseband frequency allows for data transfer in the order of several Gbit/s. Due to the small wavelength in the mm range only small structures are needed for the transmitting and receiving electronics. The 60 GHz frequency band is a strong candidate for future WLAN applications hence components are already starting to be available on the market.Patch antennas produced on flexible Printed Circuit Board substrate that can be used for wireless communication in future trackers are presented in this article. The antennas can be connected to transceivers for data transmission/reception or be connected by wave-guides to structures capable of bringing the 60 GHz signal behind boundaries. Results on simulation and fabrication of these antennas are

  10. Proposal of Wireless Traffic Control Schemes for Wireless LANs

    NASA Astrophysics Data System (ADS)

    Hiraguri, Takefumi; Ichikawa, Takeo; Iizuka, Masataka; Kubota, Shuji

    This paper proposes two traffic control schemes to support the communication quality of multimedia streaming services such as VoIP and audio/video over IEEE 802.11 wireless LAN systems. The main features of the proposed scheme are bandwidth control for each flow of the multimedia streaming service and load balancing between access points (APs) of the wireless LAN by using information of data link, network and transport layers. The proposed schemes are implemented on a Linux machine which is called the wireless traffic controller (WTC). The WTC connects a high capacity backbone network and an access network to which the APs are attached. We evaluated the performance of the proposed WTC and confirmed that the communication quality of the multimedia streaming would be greatly improved by using this technique.

  11. A Wireless Communications Systems Laboratory Course

    ERIC Educational Resources Information Center

    Guzelgoz, Sabih; Arslan, Huseyin

    2010-01-01

    A novel wireless communications systems laboratory course is introduced. The course teaches students how to design, test, and simulate wireless systems using modern instrumentation and computer-aided design (CAD) software. One of the objectives of the course is to help students understand the theoretical concepts behind wireless communication…

  12. Wireless Andrew: Everywhere You Want To Be.

    ERIC Educational Resources Information Center

    Futhey, Tracy

    2000-01-01

    Describes the wireless local area network at Carnegie Mellon University. Highlights include classroom applications, particularly in the Business School; the use of laptop computers configured with wireless technology; handheld computers, including use for testing; and assuring appropriate uses of wireless technology. (LRW)

  13. A low-cost biomedical signal transceiver based on a Bluetooth wireless system.

    PubMed

    Fazel-Rezai, Reza; Pauls, Mark; Slawinski, David

    2007-01-01

    Most current wireless biomedical signal transceivers use range-limiting communication. This work presents a low-cost biomedical signal transceiver that uses Bluetooth wireless technology. The design is implemented in a modular form to be adaptable to different types of biomedical signals. The signal front end obtains and processes incoming signals, which are then transmitted via a microcontroller and wireless module. Near real-time receive software in LabVIEW was developed to demonstrate the system capability. The completed transmitter prototype successfully transmits ECG signals, and is able to simultaneously send multiple signals. The sampling rate of the transmitter is fast enough to send up to thirteen ECG signals simultaneously, with an error rate below 0.1% for transmission exceeding 65 meters. A low-cost wireless biomedical transceiver has many applications, such as real-time monitoring of patients with a known condition in non-clinical settings.

  14. A Wireless Control System with Mutual Use of Control Signals for Cooperative Machines

    NASA Astrophysics Data System (ADS)

    Kondo, Tsugunori; Kobayashi, Kentaro; Katayama, Masaaki

    This paper discusses a wireless control system for cooperative motion of multiple machines, and clarifies the influence of packet losses on the system behavior. We focus on the synchronization of the motion of the machines, and using the nature of wireless, we propose a new wireless control scheme for maintaining the synchronization performance under packet loss conditions. In the proposed scheme, each controlled object (plant) utilizes control information destined for all plants, and the main controller also utilizes state information of all plants. The additional information of the other controller-plant pairs is used to compensate lost information. As an example of the controlled plants, rotary inverted pendulums, which move synchronously with wireless connections in their control-feedback loops, are considered. Numerical examples confirm the superiority of the proposed scheme from the view-point of the synchronization of the motion of the plants.

  15. A wireless monitoring system for Hydrocephalus shunts.

    PubMed

    Narayanaswamy, A; Nourani, M; Tamil, L; Bianco, S

    2015-08-01

    Patients with Hydrocephalus are usually treated by diverting the excess Cerebrospinal Fluid (CSF) to other parts of the body using shunts. More than 40 percentage of shunts implanted fail within the first two years. Obstruction in the shunts is one of the major causes of failure (45 percent) and the detection of obstruction reduces the complexity of the revision surgery. This paper describes a proposed wireless monitoring system for clog detection and flow measurement in shunts. A prototype was built using multiple pressure sensors along the shunt catheters for sensing the location of clog and flow rate. Regular monitoring of flow rates can be used to adjust the valve in the shunt to prevent over drainage or under drainage of CSF. The accuracy of the flow measurement is more than 90 percent.

  16. Detecting vital signs with wearable wireless sensors.

    PubMed

    Yilmaz, Tuba; Foster, Robert; Hao, Yang

    2010-01-01

    The emergence of wireless technologies and advancements in on-body sensor design can enable change in the conventional health-care system, replacing it with wearable health-care systems, centred on the individual. Wearable monitoring systems can provide continuous physiological data, as well as better information regarding the general health of individuals. Thus, such vital-sign monitoring systems will reduce health-care costs by disease prevention and enhance the quality of life with disease management. In this paper, recent progress in non-invasive monitoring technologies for chronic disease management is reviewed. In particular, devices and techniques for monitoring blood pressure, blood glucose levels, cardiac activity and respiratory activity are discussed; in addition, on-body propagation issues for multiple sensors are presented.

  17. Detecting Vital Signs with Wearable Wireless Sensors

    PubMed Central

    Yilmaz, Tuba; Foster, Robert; Hao, Yang

    2010-01-01

    The emergence of wireless technologies and advancements in on-body sensor design can enable change in the conventional health-care system, replacing it with wearable health-care systems, centred on the individual. Wearable monitoring systems can provide continuous physiological data, as well as better information regarding the general health of individuals. Thus, such vital-sign monitoring systems will reduce health-care costs by disease prevention and enhance the quality of life with disease management. In this paper, recent progress in non-invasive monitoring technologies for chronic disease management is reviewed. In particular, devices and techniques for monitoring blood pressure, blood glucose levels, cardiac activity and respiratory activity are discussed; in addition, on-body propagation issues for multiple sensors are presented. PMID:22163501

  18. Portable Wireless LAN Device and Two-way Radio Threat Assessment for Aircraft Navigation Radios

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Williams, Reuben A.; Smith, Laura J.; Salud, Maria Theresa P.

    2003-01-01

    Measurement processes, data and analysis are provided to address the concern for Wireless Local Area Network devices and two-way radios to cause electromagnetic interference to aircraft navigation radio systems. A radiated emission measurement process is developed and spurious radiated emissions from various devices are characterized using reverberation chambers. Spurious radiated emissions in aircraft radio frequency bands from several wireless network devices are compared with baseline emissions from standard computer laptops and personal digital assistants. In addition, spurious radiated emission data in aircraft radio frequency bands from seven pairs of two-way radios are provided, A description of the measurement process, device modes of operation and the measurement results are reported. Aircraft interference path loss measurements were conducted on four Boeing 747 and Boeing 737 aircraft for several aircraft radio systems. The measurement approach is described and the path loss results are compared with existing data from reference documents, standards, and NASA partnerships. In-band on-channel interference thresholds are compiled from an existing reference document. Using these data, a risk assessment is provided for interference from wireless network devices and two-way radios to aircraft systems, including Localizer, Glideslope, Very High Frequency Omnidirectional Range, Microwave Landing System and Global Positioning System. The report compares the interference risks associated with emissions from wireless network devices and two-way radios against standard laptops and personal digital assistants. Existing receiver interference threshold references are identified as to require more data for better interference risk assessments.

  19. Influence of propagation in digital wireless beam, microwave links

    NASA Astrophysics Data System (ADS)

    Bursztejn, J.

    1984-10-01

    Methods are presented for determining the parameters which permit the prediction of the quality of tropospheric scattering and line of sight microwave links. Wireless beam, microwave links with tropospheric scattering are considered based on experiments for determining the coherence band which is the essential parameter for digital transmission by tropospheric scattering. The effects of propagation difficulties in line of sight links are discussed with focus on depolarization and selective fading. Experimental results are given which permit calculating the sensitivity of equipment and predicting the quality of the links.

  20. Automated Negotiation for Resource Assignment in Wireless Surveillance Sensor Networks

    PubMed Central

    de la Hoz, Enrique; Gimenez-Guzman, Jose Manuel; Marsa-Maestre, Ivan; Orden, David

    2015-01-01

    Due to the low cost of CMOS IP-based cameras, wireless surveillance sensor networks have emerged as a new application of sensor networks able to monitor public or private areas or even country borders. Since these networks are bandwidth intensive and the radioelectric spectrum is limited, especially in unlicensed bands, it is mandatory to assign frequency channels in a smart manner. In this work, we propose the application of automated negotiation techniques for frequency assignment. Results show that these techniques are very suitable for the problem, being able to obtain the best solutions among the techniques with which we have compared them. PMID:26610512

  1. Lessons Learned from Deployment of Wireless LAN Technology

    PubMed Central

    SooHoo, Spencer L.; Duncan, Ray

    2001-01-01

    The adoption of IEEE standard 802.11b for wireless LAN technology fostered the rapid development of devices that utilize the 2.45Ghz ISM (Industrial, Scientific and Medical) frequency band. In the healthcare setting, this provides some unique opportunities to provide better, low cost mobile access to data for clinical use as well as providing some economic solutions for wide deployment of bandwidth-intensive applications over a large geographical area This poster details some the lessons we have learned as we deploy this technology.

  2. Automated Negotiation for Resource Assignment in Wireless Surveillance Sensor Networks.

    PubMed

    de la Hoz, Enrique; Gimenez-Guzman, Jose Manuel; Marsa-Maestre, Ivan; Orden, David

    2015-01-01

    Due to the low cost of CMOS IP-based cameras, wireless surveillance sensor networks have emerged as a new application of sensor networks able to monitor public or private areas or even country borders. Since these networks are bandwidth intensive and the radioelectric spectrum is limited, especially in unlicensed bands, it is mandatory to assign frequency channels in a smart manner. In this work, we propose the application of automated negotiation techniques for frequency assignment. Results show that these techniques are very suitable for the problem, being able to obtain the best solutions among the techniques with which we have compared them.

  3. Competition at the Wireless Sensor Network MAC Layer: Low Power Probing interfering with X-MAC

    NASA Astrophysics Data System (ADS)

    Zacharias, Sven; Newe, Thomas

    2011-08-01

    Wireless Sensor Networks (WSNs) combine sensors with computer networks and enable very dense, in-situ and live measurements of data over a large area. Since this emerging technology has the potential to be embedded almost everywhere for numberless applications, interference between different networks can become a serious issue. For most WSNs, it is assumed today that the network medium access is non-competitive. On the basis of X-MAC interfered by Low Power Probing, this paper shows the danger and the effects of different sensor networks communicating on a single wireless channel of the 2.4 GHz band, which is used by the IEEE 802.15.4 standard.

  4. 2.4 GHz wireless sensor network for smart electronic shirts

    NASA Astrophysics Data System (ADS)

    Carmo, J. P.; Mendes, P. M.; Couto, C.; Correia, J. H.

    2005-07-01

    This paper presents a wireless sensor network for smart electronic shirts. This allows the monitoring of individual biomedical data, such the cardio-respiratory function. The solution chosen to transmit the body's measured signals for further processing was the use of a wireless link, working at the 2.4 GHz ISM band. A radio-frequency transceiver chip was designed in a UMC RF 0.18 μm CMOS process. The power supply of the transceiver is 1.8 V. Simulations show a power consumption of 12.9 mW. Innovative topics concerning efficient power management was taken into account during the design of the transceiver.

  5. [Development of Bluetooth wireless sensors].

    PubMed

    Moor, C; Schwaibold, M; Roth, H; Schöchlin, J; Bolz, A

    2002-01-01

    Wireless communication could help to overcome current obstacles in medical devices and could enable medical services to offer completely new scenarios in health care. The Bluetooth technology which is the upcoming global market leader in wireless communication turned out to be perfectly suited not only for consumer market products but also in the medical environment [1]. It offers a low power, low cost connection in the medium range of 1-100 m with a bandwidth of currently 723.2 kbaud. This paper describes the development of a wireless ECG device and a Pulse Oximeter. Equipped with a Bluetooth port, the measurement devices are enabled to transmit data between the sensor and a Bluetooth-monitor. Therefore, CSR's Bluetooth protocol embedded two-processor and embedded single-processor architecture has been used.

  6. Information Assurance in Wireless Networks

    NASA Astrophysics Data System (ADS)

    Kabara, Joseph; Krishnamurthy, Prashant; Tipper, David

    2001-09-01

    Emerging wireless networks will contain a hybrid infrastructure based on fixed, mobile and ad hoc topologies and technologies. In such a dynamic architecture, we define information assurance as the provisions for both information security and information availability. The implications of this definition are that the wireless network architecture must (a) provide sufficient security measures, (b) be survivable under node or link attack or failure and (c) be designed such that sufficient capacity remains for all critical services (and preferably most other services) in the event of attack or component failure. We have begun a research project to investigate the provision of information assurance for wireless networks viz. survivability, security and availability and here discuss the issues and challenges therein.

  7. Wireless communication of real-time ultrasound data and control

    NASA Astrophysics Data System (ADS)

    Tobias, Richard J.

    2015-03-01

    The Internet of Things (IoT) is expected to grow to 26 billion connected devices by 2020, plus the PC, smart phone, and tablet segment that includes mobile Health (mHealth) connected devices is projected to account for another 7.3 billion units by 2020. This paper explores some of the real-time constraints on the data-flow and control of a wireless connected ultrasound machine. The paper will define an ultrasound server and the capabilities necessary for real-time use of the device. The concept of an ultrasound server wirelessly (or over any network) connected to multiple lightweight clients on devices like an iPad, iPhone, or Android-based tablet, smartphone and other network-attached displays (i.e., Google Glass) is explored. Latency in the ultrasound data stream is one of the key areas to measure and to focus on keeping as small as possible (<30ms) so that the ultrasound operator can see what is at the probe at that moment, instead of where the probe was a short period earlier. By keeping the latency less than 30ms, the operator will feel like the data he sees on the wireless connected devices is running in real-time with the operator. The second parameter is the management of bandwidth. At minimum we need to be able to see 20 frames-per- second. It is possible to achieve ultrasound in triplex mode at >20 frames-per-second on a properly configured wireless network. The ultrasound server needs to be designed to accept multiple ultrasound data clients and multiple control clients. A description of the server and some of its key features will be described.

  8. Wireless device monitoring systems and monitoring devices, and associated methods

    DOEpatents

    McCown, Steven H; Derr, Kurt W; Rohde, Kenneth W

    2014-05-27

    Wireless device monitoring systems and monitoring devices include a communications module for receiving wireless communications of a wireless device. Processing circuitry is coupled with the communications module and configured to process the wireless communications to determine whether the wireless device is authorized or unauthorized to be present at the monitored area based on identification information of the wireless device. Methods of monitoring for the presence and identity of wireless devices are also provided.

  9. Wireless Communications in Reverberant Environments

    NASA Astrophysics Data System (ADS)

    Measel, Ryan Thomas

    Implementation of WLANs in reverberant environments, such as industrial facilities, naval vessels, aircraft, and spacecraft, has proven challenging, because rich electromagnetic scattering can degrade link quality through multipath interference. As a result, the adoption of Wireless LANs in these environments has been slow. Previous studies concerning reverberant environments have focused on characterizing electromagnetic properties for the purpose of electromagnetic compatibility testing. Little attention has been given to the performance of wireless communications. In this effort, the effect of electromagnetic reverberance on wireless communications is investigated in order to assess the feasibility of WLAN deployment. Work centered around two experimental measurement campaigns. The first campaign was performed in coupled reverberation chambers. The reverberation chambers provided a controllable environment which was configured to emulate the reverberance of below-deck spaces on a naval vessel. The process for quantifying and configuring the electromagnetic properties of a reverberation chamber is presented. The second campaign was performed on a naval vessel. Experimentation was conducted in a variety of locations on the ship. Locations were selected to represent a wide range of practical environments. Across both campaigns, several environment and node parameters were evaluated: level of reverberance, cavity coupling (effective aperture size), and LOS versus NLOS links. Additionally, advanced physical layer schemes and reconfigurable antennas are presented as methods to improve performance and mitigate multipath interference. To perform this work, a measurement platform and testing protocol were developed for systematic characterization of wireless communications in reverberant environments. The primary contributions of this work are empirical characterization of wireless communications in reverberant environments, approaches to improving the performance of

  10. Optical wireless communications to OC-768 and beyond

    NASA Astrophysics Data System (ADS)

    Medved, David B.; Davidovich, Leonid

    2001-10-01

    Laser and LED-based wireless communication systems are currently providing license-free interconnection for broadband voice, data and video transport. These systems allow for the immediate, reliable and low-cost extension of copper and fiber-based networks to any end user, providing efficient First Mile bypass access to high data rate backbone networks at speeds ranging from T-1 voice to full throughput ATM at 155 Mbps and up to Gigabit Ethernet. These wireless optical beams constitute a Virtual Fiber in the air, providing the capabilities of fiber in situations where wired connectivity is unavailable, impractical, expensive or slow-to-implement, while achieving a combination of low cost, speed and reliability that cannot be matched by microwave, mm wave, spread spectrum or other competing (actually complementary) wireless technologies. The carrier frequency of the optical beam is about 10,000 times higher than the highest frequencies used by the millimeter wave technology. By means of Wavelength Division Multiplexing more than 1000 independent data channels can be projected into the air on a single beam thus providing a potential bandwidth ten million times that of any RF solution. The twin barriers of physics and regulatory bureaucracy to this essentially infinite wireless bandwidth are thus eliminated by this Virtual Fiber. As user density and individual bandwidth needs escalate, the optical wireless will be the preferred medium of choice in both network and cellular interconnection. A mesh topology which integrates our optical wireless systems with the latest Optical Access switches and routing equipment will be described using case study examples from Japan to South America. As the Bandwidth Blowout continues to push the limits of electronics and especially in the case of DWDM (Dense Wavelength Division Multiples), the conventional optical wireless solutions are no longer feasible. Instead of using f.o. transceivers to convert photons to electrons and thence

  11. Wireless technology for integrated manufacturing

    SciTech Connect

    Manges, W.W.; Allgood, G.O.; Shourbaji, A.A.

    1996-08-01

    This paper describes the ground breaking work in Oak Ridge facilities that now leads us to the brink of the wireless revolution in manufacturing. The focus is on solving tough technological problems necessary for success and addressing the critical issues of throughput, security, reliability, and robustness in applying wireless technology to manufacturing processes. Innovative solutions to these problems are highlighted through detailed designs and testbed implementations that demonstrate key concepts. The DOE-Oak Ridge complex represented by the Oak Ridge Centers for Manufacturing Technologies (ORCMT) continues to develop these technologies and will continue to focus on solving tough manufacturing problems.

  12. WIRELESS FOR A NUCLEAR FACILITY

    SciTech Connect

    Shull, D; Joe Cordaro, J

    2007-03-28

    The introduction of wireless technology into a government site where nuclear material is processed and stored brings new meaning to the term ''harsh environment''. At SRNL, we are attempting to address not only the harsh RF and harsh physical environment common to industrial facilities, but also the ''harsh'' regulatory environment necessitated by the nature of the business at our site. We will discuss our concepts, processes, and expected outcomes in our attempts to surmount the roadblocks and reap the benefits of wireless in our ''factory''.

  13. Wireless Augmented Reality Communication System

    NASA Technical Reports Server (NTRS)

    Devereaux, Ann (Inventor); Jedrey, Thomas (Inventor); Agan, Martin (Inventor)

    2015-01-01

    A portable unit is for video communication to select a user name in a user name network. A transceiver wirelessly accesses a communication network through a wireless connection to a general purpose node coupled to the communication network. A user interface can receive user input to log on to a user name network through the communication network. The user name network has a plurality of user names, at least one of the plurality of user names is associated with a remote portable unit, logged on to the user name network and available for video communication.

  14. Reliability and throughput issues for optical wireless and RF wireless systems

    NASA Astrophysics Data System (ADS)

    Yu, Meng

    The fast development of wireless communication technologies has two main trends. On one hand, in point-to-point communications, the demand for higher throughput called for the emergence of wireless broadband techniques including optical wireless (OW). One the other hand, wireless networks are becoming pervasive. New application of wireless networks ask for more flexible system infrastructures beyond the point-to-point prototype to achieve better performance. This dissertation investigates two topics on the reliability and throughput issues of new wireless technologies. The first topic is to study the capacity, and practical forward error control strategies for OW systems. We investigate the performance of OW systems under weak atmospheric turbulence. We first investigate the capacity and power allocation for multi-laser and multi-detector systems. Our results show that uniform power allocation is a practically optimal solution for paralleled channels. We also investigate the performance of Reed Solomon (RS) codes and turbo codes for OW systems. We present RS codes as good candidates for OW systems. The second topic targets user cooperation in wireless networks. We evaluate the relative merits of amplify-forward (AF) and decode-forward (DF) in practical scenarios. Both analysis and simulations show that the overall system performance is critically affected by the quality of the inter-user channel. Following this result, we investigate two schemes to improve the overall system performance. We first investigate the impact of the relay location on the overall system performance and determine the optimal location of relay. A best-selective single-relay 1 system is proposed and evaluated. Through the analysis of the average capacity and outage, we show that a small candidate pool of 3 to 5 relays suffices to reap most of the "geometric" gain available to a selective system. Second, we propose a new user cooperation scheme to provide an effective better inter-user channel

  15. Wireless Technologies Implications for Power Systems

    SciTech Connect

    Fuhr, Peter L; Manges, Wayne W; Schweitzer, Patrick; Kagan, Hesh

    2010-01-01

    Wireless technologies have advanced well beyond simple SCADA radio systems and point-to-point links. The current applications supported by industrial-grade wireless sensors and systems range from field measurements (classic I/O) to voice, video, asset tracking, mobile operators, etc. Which such a wide array of supported applications, the belief that wireless technology will only impact power systems in terms of wireless sensors is shortsighted. This paper, coauthored by a group of individuals intimately involved in the general realm of industrial wireless , presents a simple snapshot of current radio technologies that are used (or seriously contemplated for use) in power systems.

  16. Photonic band gap materials

    SciTech Connect

    Soukoulis, C.M. |

    1993-12-31

    An overview of the theoretical and experimental efforts in obtaining a photonic band gap, a frequency band in three-dimensional dielectric structures in which electromagnetic waves are forbidden, is presented.

  17. Wireless Ways: Business and Personal Applications of Wireless Technology.

    ERIC Educational Resources Information Center

    Chung, Joe

    2001-01-01

    Describes the Art Technology Group (ATG), an electronic business and customer management company, and the work they have done with wireless technology. Highlights include designing virtual offices and supporting the resulting virtual community; the mobility it allows; problems with bandwidth; and display issues. (LRW)

  18. Wireless multichannel biopotential recording using an integrated FM telemetry circuit.

    PubMed

    Mohseni, Pedram; Najafi, Khalil; Eliades, Steven J; Wang, Xiaoqin

    2005-09-01

    This paper presents a four-channel telemetric microsystem featuring on-chip alternating current amplification, direct current baseline stabilization, clock generation, time-division multiplexing, and wireless frequency-modulation transmission of microvolt- and millivolt-range input biopotentials in the very high frequency band of 94-98 MHz over a distance of approximately 0.5 m. It consists of a 4.84-mm2 integrated circuit, fabricated using a 1.5-microm double-poly double-metal n-well standard complementary metal-oxide semiconductor process, interfaced with only three off-chip components on a custom-designed printed-circuit board that measures 1.7 x 1.2 x 0.16 cm3, and weighs 1.1 g including two miniature 1.5-V batteries. We characterize the microsystem performance, operating in a truly wireless fashion in single-channel and multichannel operation modes, via extensive benchtop and in vitro tests in saline utilizing two different micromachined neural recording microelectrodes, while dissipating approximately 2.2 mW from a 3-V power supply. Moreover, we demonstrate successful wireless in vivo recording of spontaneous neural activity at 96.2 MHz from the auditory cortex of an awake marmoset monkey at several transmission distances ranging from 10 to 50 cm with signal-to-noise ratios in the range of 8.4-9.5 dB.

  19. A vibration powered wireless mote on the Forth Road Bridge

    NASA Astrophysics Data System (ADS)

    Jia, Yu; Yan, Jize; Feng, Tao; Du, Sijun; Fidler, Paul; Soga, Kenichi; Middleton, Campbell; Seshia, Ashwin A.

    2015-12-01

    The conventional resonant-approaches to scavenge kinetic energy are typically confined to narrow and single-band frequencies. The vibration energy harvester device reported here combines both direct resonance and parametric resonance in order to enhance the power responsiveness towards more efficient harnessing of real-world ambient vibration. A packaged electromagnetic harvester designed to operate in both of these resonant regimes was tested in situ on the Forth Road Bridge. In the field-site, the harvester, with an operational volume of ∼126 cm3, was capable of recovering in excess of 1 mW average raw AC power from the traffic-induced vibrations in the lateral bracing structures underneath the bridge deck. The harvester was integrated off-board with a power conditioning circuit and a wireless mote. Duty- cycled wireless transmissions from the vibration-powered mote was successfully sustained by the recovered ambient energy. This limited duration field test provides the initial validation for realising vibration-powered wireless structural health monitoring systems in real world infrastructure, where the vibration profile is both broadband and intermittent.

  20. Wireless device connection problems and design solutions

    NASA Astrophysics Data System (ADS)

    Song, Ji-Won; Norman, Donald; Nam, Tek-Jin; Qin, Shengfeng

    2016-09-01

    Users, especially the non-expert users, commonly experience problems when connecting multiple devices with interoperability. While studies on multiple device connections are mostly concentrated on spontaneous device association techniques with a focus on security aspects, the research on user interaction for device connection is still limited. More research into understanding people is needed for designers to devise usable techniques. This research applies the Research-through-Design method and studies the non-expert users' interactions in establishing wireless connections between devices. The "Learning from Examples" concept is adopted to develop a study focus line by learning from the expert users' interaction with devices. This focus line is then used for guiding researchers to explore the non-expert users' difficulties at each stage of the focus line. Finally, the Research-through-Design approach is used to understand the users' difficulties, gain insights to design problems and suggest usable solutions. When connecting a device, the user is required to manage not only the device's functionality but also the interaction between devices. Based on learning from failures, an important insight is found that the existing design approach to improve single-device interaction issues, such as improvements to graphical user interfaces or computer guidance, cannot help users to handle problems between multiple devices. This study finally proposes a desirable user-device interaction in which images of two devices function together with a system image to provide the user with feedback on the status of the connection, which allows them to infer any required actions.

  1. Strategies for Optimal MAC Parameters Tuning in IEEE 802.15.6 Wearable Wireless Sensor Networks.

    PubMed

    Alam, Muhammad Mahtab; Ben Hamida, Elyes

    2015-09-01

    Wireless body area networks (WBAN) has penetrated immensely in revolutionizing the classical heath-care system. Recently, number of WBAN applications has emerged which introduce potential limits to existing solutions. In particular, IEEE 802.15.6 standard has provided great flexibility, provisions and capabilities to deal emerging applications. In this paper, we investigate the application-specific throughput analysis by fine-tuning the physical (PHY) and medium access control (MAC) parameters of the IEEE 802.15.6 standard. Based on PHY characterizations in narrow band, at the MAC layer, carrier sense multiple access collision avoidance (CSMA/CA) and scheduled access protocols are extensively analyzed. It is concluded that, IEEE 802.15.6 standard can satisfy most of the WBANs applications throughput requirements by maximum achieving 680 Kbps. However, those emerging applications which require high quality audio or video transmissions, standard is not able to meet their constraints. Moreover, delay, energy efficiency and successful packet reception are considered as key performance metrics for comparing the MAC protocols. CSMA/CA protocol provides the best results to meet the delay constraints of medical and non-medical WBAN applications. Whereas, the scheduled access approach, performs very well both in energy efficiency and packet reception ratio.

  2. The wireless Web and patient care.

    PubMed

    Bergeron, B P

    2001-01-01

    Wireless computing, when integrated with the Web, is poised to revolutionize the practice and teaching of medicine. As vendors introduce wireless Web technologies in the medical community that have been used successfully in the business and consumer markets, clinicians can expect profound increases in the amount of patient data, as well as the ease with which those data are acquired, analyzed, and disseminated. The enabling technologies involved in this transformation to the wireless Web range from the new generation of wireless PDAs, eBooks, and wireless data acquisition peripherals to new wireless network protocols. The rate-limiting step in the application of this technology in medicine is not technology per se but rather how quickly clinicians and their patients come to accept and appreciate the benefits and limitations of the application of wireless Web technology.

  3. Innovative techniques for extending the range and node limits in Bluetooth-based wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Fraser, Matthew J.; James, Daniel A.; Thiel, David V.

    2005-12-01

    Wireless networks for sensor applications are required to support an adequate data throughput, range, node density and must consume as little power as possible. The Bluetooth specification has been designed for low power, medium data rate, cable replacement solutions and is therefore useful for wireless sensor networks. However it has a limitation of a maximum number of eight active devices per Bluetooth network (piconet). To be useful in wireless sensor networks a Bluetooth piconet requires a means to communicate to more than the maximum of eight active devices. This paper demonstrates techniques for expanding the usefulness of Bluetooth for wireless sensor networks. This has been done by using multiple access points, sharing the active member addresses of the Bluetooth piconet and utilising multiple piconet and scatternet tree structures. A comparison of existing piconet handoff mechanisms has been conducted and these have been evaluated for feasibility with the available hardware's limitations. Scatternet and piconet sharing mechanisms have been developed that allow a Bluetooth structure to support more than eight devices. These structures have been implemented with existing Bluetooth hardware and are compared via theoretical simulation and experimental results. The developed network of multiple Bluetooth access points combined with the developed Bluetooth structures provides several wireless networks suitable for sensor applications.

  4. Underwater optical wireless communication network

    NASA Astrophysics Data System (ADS)

    Arnon, Shlomi

    2010-01-01

    The growing need for underwater observation and subsea monitoring systems has stimulated considerable interest in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. This communication technology is expected to play an important role in investigating climate change, in monitoring biological, biogeochemical, evolutionary, and ecological changes in the sea, ocean, and lake environments, and in helping to control and maintain oil production facilities and harbors using unmanned underwater vehicles (UUVs), submarines, ships, buoys, and divers. However, the present technology of underwater acoustic communication cannot provide the high data rate required to investigate and monitor these environments and facilities. Optical wireless communication has been proposed as the best alternative to meet this challenge. Models are presented for three kinds of optical wireless communication links: (a) a line-of-sight link, (b) a modulating retroreflector link, and (c) a reflective link, all of which can provide the required data rate. We analyze the link performance based on these models. From the analysis, it is clear that as the water absorption increases, the communication performance decreases dramatically for the three link types. However, by using the scattered light it was possible to mitigate this decrease in some cases. It is concluded from the analysis that a high-data-rate underwater optical wireless network is a feasible solution for emerging applications such as UUV-to-UUV links and networks of sensors, and extended ranges in these applications could be achieved by applying a multi-hop concept.

  5. Socially Aware Heterogeneous Wireless Networks

    PubMed Central

    Kosmides, Pavlos; Adamopoulou, Evgenia; Demestichas, Konstantinos; Theologou, Michael; Anagnostou, Miltiades; Rouskas, Angelos

    2015-01-01

    The development of smart cities has been the epicentre of many researchers’ efforts during the past decade. One of the key requirements for smart city networks is mobility and this is the reason stable, reliable and high-quality wireless communications are needed in order to connect people and devices. Most research efforts so far, have used different kinds of wireless and sensor networks, making interoperability rather difficult to accomplish in smart cities. One common solution proposed in the recent literature is the use of software defined networks (SDNs), in order to enhance interoperability among the various heterogeneous wireless networks. In addition, SDNs can take advantage of the data retrieved from available sensors and use them as part of the intelligent decision making process contacted during the resource allocation procedure. In this paper, we propose an architecture combining heterogeneous wireless networks with social networks using SDNs. Specifically, we exploit the information retrieved from location based social networks regarding users’ locations and we attempt to predict areas that will be crowded by using specially-designed machine learning techniques. By recognizing possible crowded areas, we can provide mobile operators with recommendations about areas requiring datacell activation or deactivation. PMID:26110402

  6. The Wireless Student & the Library.

    ERIC Educational Resources Information Center

    Drew, Bill

    2002-01-01

    Describes a program at the State University of New York College of Agriculture and Technology at Morrisville (SUNY-Morrisville) developed with IBM called ThinkPad University that integrates computers into the teaching and learning environment. Explains a partnership with Raytheon that provides wireless connectivity; and discusses changes in…

  7. Wireless Crew Communication Feasibility Assessment

    NASA Technical Reports Server (NTRS)

    Archer, Ronald D.; Romero, Andy; Juge, David

    2016-01-01

    Ongoing discussions with crew currently onboard the ISS as well as the crew debriefs from completed ISS missions indicate that issues associated with the lack of wireless crew communication results in increased crew task completion times and lower productivity, creates cable management issues, and increases crew frustration.

  8. Socially Aware Heterogeneous Wireless Networks.

    PubMed

    Kosmides, Pavlos; Adamopoulou, Evgenia; Demestichas, Konstantinos; Theologou, Michael; Anagnostou, Miltiades; Rouskas, Angelos

    2015-06-11

    The development of smart cities has been the epicentre of many researchers' efforts during the past decade. One of the key requirements for smart city networks is mobility and this is the reason stable, reliable and high-quality wireless communications are needed in order to connect people and devices. Most research efforts so far, have used different kinds of wireless and sensor networks, making interoperability rather difficult to accomplish in smart cities. One common solution proposed in the recent literature is the use of software defined networks (SDNs), in order to enhance interoperability among the various heterogeneous wireless networks. In addition, SDNs can take advantage of the data retrieved from available sensors and use them as part of the intelligent decision making process contacted during the resource allocation procedure. In this paper, we propose an architecture combining heterogeneous wireless networks with social networks using SDNs. Specifically, we exploit the information retrieved from location based social networks regarding users' locations and we attempt to predict areas that will be crowded by using specially-designed machine learning techniques. By recognizing possible crowded areas, we can provide mobile operators with recommendations about areas requiring datacell activation or deactivation.

  9. Socially Aware Heterogeneous Wireless Networks.

    PubMed

    Kosmides, Pavlos; Adamopoulou, Evgenia; Demestichas, Konstantinos; Theologou, Michael; Anagnostou, Miltiades; Rouskas, Angelos

    2015-01-01

    The development of smart cities has been the epicentre of many researchers' efforts during the past decade. One of the key requirements for smart city networks is mobility and this is the reason stable, reliable and high-quality wireless communications are needed in order to connect people and devices. Most research efforts so far, have used different kinds of wireless and sensor networks, making interoperability rather difficult to accomplish in smart cities. One common solution proposed in the recent literature is the use of software defined networks (SDNs), in order to enhance interoperability among the various heterogeneous wireless networks. In addition, SDNs can take advantage of the data retrieved from available sensors and use them as part of the intelligent decision making process contacted during the resource allocation procedure. In this paper, we propose an architecture combining heterogeneous wireless networks with social networks using SDNs. Specifically, we exploit the information retrieved from location based social networks regarding users' locations and we attempt to predict areas that will be crowded by using specially-designed machine learning techniques. By recognizing possible crowded areas, we can provide mobile operators with recommendations about areas requiring datacell activation or deactivation. PMID:26110402

  10. Gigabit Wireless for Network Connectivity

    ERIC Educational Resources Information Center

    Schoedel, Eric

    2009-01-01

    Uninterrupted, high-bandwidth network connectivity is crucial for higher education. Colleges and universities increasingly adopt gigabit wireless solutions because of their fiber-equivalent performance, quick implementation, and significant return on investment. For just those reasons, Rush University Medical Center switched from free space optics…

  11. Breaking Free with Wireless Networks.

    ERIC Educational Resources Information Center

    Fleischman, John

    2002-01-01

    Discusses wireless local area networks (LANs) which typically consist of laptop computers that connect to fixed access points via infrared or radio signals. Topics include wide area networks; personal area networks; problems, including limitations of available bandwidth, interference, and security concerns; use in education; interoperability;…

  12. Fault Tolerance in ZigBee Wireless Sensor Networks

    NASA Technical Reports Server (NTRS)

    Alena, Richard; Gilstrap, Ray; Baldwin, Jarren; Stone, Thom; Wilson, Pete

    2011-01-01

    Wireless sensor networks (WSN) based on the IEEE 802.15.4 Personal Area Network standard are finding increasing use in the home automation and emerging smart energy markets. The network and application layers, based on the ZigBee 2007 PRO Standard, provide a convenient framework for component-based software that supports customer solutions from multiple vendors. This technology is supported by System-on-a-Chip solutions, resulting in extremely small and low-power nodes. The Wireless Connections in Space Project addresses the aerospace flight domain for both flight-critical and non-critical avionics. WSNs provide the inherent fault tolerance required for aerospace applications utilizing such technology. The team from Ames Research Center has developed techniques for assessing the fault tolerance of ZigBee WSNs challenged by radio frequency (RF) interference or WSN node failure.

  13. Deployable Wireless Camera Penetrators

    NASA Technical Reports Server (NTRS)

    Badescu, Mircea; Jones, Jack; Sherrit, Stewart; Wu, Jiunn Jeng

    2008-01-01

    A lightweight, low-power camera dart has been designed and tested for context imaging of sampling sites and ground surveys from an aerobot or an orbiting spacecraft in a microgravity environment. The camera penetrators also can be used to image any line-of-sight surface, such as cliff walls, that is difficult to access. Tethered cameras to inspect the surfaces of planetary bodies use both power and signal transmission lines to operate. A tether adds the possibility of inadvertently anchoring the aerobot, and requires some form of station-keeping capability of the aerobot if extended examination time is required. The new camera penetrators are deployed without a tether, weigh less than 30 grams, and are disposable. They are designed to drop from any altitude with the boost in transmitting power currently demonstrated at approximately 100-m line-of-sight. The penetrators also can be deployed to monitor lander or rover operations from a distance, and can be used for surface surveys or for context information gathering from a touch-and-go sampling site. Thanks to wireless operation, the complexity of the sampling or survey mechanisms may be reduced. The penetrators may be battery powered for short-duration missions, or have solar panels for longer or intermittent duration missions. The imaging device is embedded in the penetrator, which is dropped or projected at the surface of a study site at 90 to the surface. Mirrors can be used in the design to image the ground or the horizon. Some of the camera features were tested using commercial "nanny" or "spy" camera components with the charge-coupled device (CCD) looking at a direction parallel to the ground. Figure 1 shows components of one camera that weighs less than 8 g and occupies a volume of 11 cm3. This camera could transmit a standard television signal, including sound, up to 100 m. Figure 2 shows the CAD models of a version of the penetrator. A low-volume array of such penetrator cameras could be deployed from an

  14. (abstract) Experimental Results From Internetworking Data Applications Over Various Wireless Networks Using a Single Flexible Error Control Protocol

    NASA Technical Reports Server (NTRS)

    Kanai, T.; Kramer, M.; McAuley, A. J.; Nowack, S.; Pinck, D. S.; Ramirez, G.; Stewart, I.; Tohme, H.; Tong, L.

    1995-01-01

    This paper describes results from several wireless field trials in New Jersey, California, and Colorado, conducted jointly by researchers at Bellcore, JPL, and US West over the course of 1993 and 1994. During these trials, applications communicated over multiple wireless networks including satellite, low power PCS, high power cellular, packet data, and the wireline Public Switched Telecommunications Network (PSTN). Key goals included 1) designing data applications and an API suited to mobile users, 2) investigating internetworking issues, 3) characterizing wireless networks under various field conditions, and 4) comparing the performance of different protocol mechanisms over the diverse networks and applications. We describe experimental results for different protocol mechanisms and parameters, such as acknowledgment schemes and packet sizes. We show the need for powerful error control mechanisms such as selective acknowledgements and combining data from multiple transmissions. We highlight the possibility of a common protocol for all wireless networks, from micro-cellular PCS to satellite networks.

  15. The Physics of III-V Heterojunction Devices in Wireless Communications

    NASA Astrophysics Data System (ADS)

    Johnson, Karl

    2003-03-01

    III-V heterojunction devices have become pervasive in wireless communication appliances. In particular, the low voltage, high efficiency power amplifier transmitters in cellular phones are dominated by heterojunction bipolar transistors (HBT), psuedomorphic high electron mobility transistors (pHEMT) and heterojunction field effect transistors (HFET). Further, these III-V heterojunction devices are also appearing in infrastructure applications such as cellular base stations, wireless local area network (WLAN) and cable television (CATV) line amplifiers. The design of these devices requires unique band gap engineering in order to meet the cost, performance and ruggedness in the linear and saturated power modes required by today's cellular modulation protocols. This presentation will address the physics behind the design, development and operation of these technologies leading to their optimization for the wireless market place.

  16. Wireless Data Acquisition of Transient Signals for Mobile Spectrometry Applications.

    PubMed

    Trzcinski, Peter; Weagant, Scott; Karanassios, Vassili

    2016-05-01

    Wireless data acquisition using smartphones or handhelds offers increased mobility, it provides reduced size and weight, it has low electrical power requirements, and (in some cases) it has an ability to access the internet. Thus, it is well suited for mobile spectrometry applications using miniaturized, field-portable spectrometers, or detectors for chemical analysis in the field (i.e., on-site). There are four main wireless communications standards that can be used for wireless data acquisition, namely ZigBee, Bluetooth, Wi-Fi, and UWB (ultra-wide band). These are briefly reviewed and are evaluated for applicability to data acquisition of transient signals (i.e., time-domain) in the field (i.e., on-site) from a miniaturized, field-portable photomultiplier tube detector and from a photodiode array detector installed in a miniaturized, field-portable fiber optic spectrometer. These are two of the most widely used detectors for optical measurements in the ultraviolet-visible range of the spectrum. A miniaturized, 3D-printed, battery-operated microplasma-on-a-chip was used for generation of transient optical emission signals. Elemental analysis from liquid microsamples, a microplasma, and a handheld or a smartphone will be used as examples. Development and potential applicability of wireless data acquisition of transient optical emission signals for taking part of the lab to the sample types of mobile, field-portable spectrometry applications will be discussed. The examples presented are drawn from past and ongoing work in the authors' laboratory. A handheld or a smartphone were used as the mobile computing devices of choice.

  17. Wireless Data Acquisition of Transient Signals for Mobile Spectrometry Applications.

    PubMed

    Trzcinski, Peter; Weagant, Scott; Karanassios, Vassili

    2016-05-01

    Wireless data acquisition using smartphones or handhelds offers increased mobility, it provides reduced size and weight, it has low electrical power requirements, and (in some cases) it has an ability to access the internet. Thus, it is well suited for mobile spectrometry applications using miniaturized, field-portable spectrometers, or detectors for chemical analysis in the field (i.e., on-site). There are four main wireless communications standards that can be used for wireless data acquisition, namely ZigBee, Bluetooth, Wi-Fi, and UWB (ultra-wide band). These are briefly reviewed and are evaluated for applicability to data acquisition of transient signals (i.e., time-domain) in the field (i.e., on-site) from a miniaturized, field-portable photomultiplier tube detector and from a photodiode array detector installed in a miniaturized, field-portable fiber optic spectrometer. These are two of the most widely used detectors for optical measurements in the ultraviolet-visible range of the spectrum. A miniaturized, 3D-printed, battery-operated microplasma-on-a-chip was used for generation of transient optical emission signals. Elemental analysis from liquid microsamples, a microplasma, and a handheld or a smartphone will be used as examples. Development and potential applicability of wireless data acquisition of transient optical emission signals for taking part of the lab to the sample types of mobile, field-portable spectrometry applications will be discussed. The examples presented are drawn from past and ongoing work in the authors' laboratory. A handheld or a smartphone were used as the mobile computing devices of choice. PMID:27006023

  18. Portable Wireless Device Threat Assessment for Aircraft Navigation Radios

    NASA Technical Reports Server (NTRS)

    Nguyen, Truong X.; Koppen, Sandra V.; Ely, Jay J.; Williams, Reuben A.; Smith, Laura J.; Salud, Maria Theresa P.

    2004-01-01

    This paper addresses the concern for Wireless Local Area Network devices and two-way radios to cause electromagnetic interference to aircraft navigation radio systems. Spurious radiated emissions from various IEEE 802.11a, 802.11b, and Bluetooth devices are characterized using reverberation chambers. The results are compared with baseline emissions from standard laptop computer and personal digital assistants (PDAs) that are currently allowed for use on aircraft. The results indicate that the WLAN devices tested are not more of a threat to aircraft navigation radios than standard laptop computers and PDAs in most aircraft bands. In addition, spurious radiated emission data from seven pairs of two-way radios are provided. These two-way radios emit at much higher levels in the bands considered. A description of the measurement process, device modes of operation and the measurement results are reported.

  19. Hazmat Cam Wireless Video System

    SciTech Connect

    Kevin L. Young

    2006-02-01

    This paper describes the Hazmat Cam Wireless Video System and its application to emergency response involving chemical, biological or radiological contamination. The Idaho National Laboratory designed the Hazmat Cam Wireless Video System to assist the National Guard Weapons of Mass Destruction - Civil Support Teams during their mission of emergency response to incidents involving weapons of mass destruction. The lightweight, handheld camera transmits encrypted, real-time video from inside a contaminated area, or hot-zone, to a command post located a safe distance away. The system includes a small wireless video camera, a true-diversity receiver, viewing console, and an optional extension link that allows the command post to be placed up to five miles from danger. It can be fully deployed by one person in a standalone configuration in less than 10 minutes. The complete system is battery powered. Each rechargeable camera battery powers the camera for 3 hours with the receiver and video monitor battery lasting 22 hours on a single charge. The camera transmits encrypted, low frequency analog video signals to a true-diversity receiver with three antennas. This unique combination of encryption and transmission technologies delivers encrypted, interference-free images to the command post under conditions where other wireless systems fail. The lightweight camera is completely waterproof for quick and easy decontamination after use. The Hazmat Cam Wireless Video System is currently being used by several National Guard Teams, the US Army, and by fire fighters. The system has been proven to greatly enhance situational awareness during the crucial, initial phase of a hazardous response allowing commanders to make better, faster, safer decisions.

  20. Analysis and design of printed antennas for wireless communications using finite difference time domain technique

    NASA Astrophysics Data System (ADS)

    Huang, Chun-Wen Paul

    Small printed antennas are becoming one of the most popular designs in personal wireless communication systems, because these antennas feature light weight, small size, high frequency operation, and high transmission efficiency. Recently, a new type of printed meander line antenna was introduced. In this dissertation, the characteristics of a class of novel meander line antennas are presented and analyzed in detail using the finite difference time domain technique. The presented designs of the meander line antennas feature small dimensions (less than 77 x 11 x 3.17 mm3), approximately 50 Ω input impedance, dual or multiple frequency bands, and operate within the 0.9-3.0 GHz range on a comparably small ground plane (59 x 25.4 mm 2). Empirical design equations and the analysis for the input impedance and operating frequencies of different designs of meander line antennas are also provided. Validations of the numerical codes used in this investigation are made by comparing the computed FDTD results for known geometries with numerical results by other methods and measurements. Prototypes of optimized printed taper meander line antennas are built, and measurements of their return loss are compared with the computational results obtained using the FDTD technique. Very good agreement is found between FDTD numerical analysis and comparison results by other numerical methods and measurements. Optimal designs are achieved by applying dual printed sleeve tuners to equal segment ratio and taper meander line antennas, which cover the frequency range 1.25 GHz to 3.0 GHz with VSWR less than 1.4 and bandwidth varied within 120-340 MHz These optimal designs may effectively support the upper PCS bands and the future 3 rd generation cellular applications.

  1. 78 FR 16827 - Commercial Operations in the 3550-3650 MHz Band

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-19

    ... the NPRM, the Wireless Telecommunications Bureau and Office of Engineering and Technology announced... workshop will focus on small cell technology ``in the context of the 3.5 GHz Band as well as database and... From the Federal Register Online via the Government Publishing Office FEDERAL...

  2. 47 CFR 27.701 - 698-746 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false 698-746 MHz bands subject to competitive bidding. 27.701 Section 27.701 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive Bidding Procedures for the...

  3. 47 CFR 27.701 - 698-746 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false 698-746 MHz bands subject to competitive bidding. 27.701 Section 27.701 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive Bidding Procedures for the...

  4. 47 CFR 27.701 - 698-746 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false 698-746 MHz bands subject to competitive bidding. 27.701 Section 27.701 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive Bidding Procedures for the...

  5. 47 CFR 27.1222 - Operations in the 2568-2572 and 2614-2618 bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Operations in the 2568-2572 and 2614-2618 bands. 27.1222 Section 27.1222 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and...

  6. 47 CFR 27.701 - 698-746 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false 698-746 MHz bands subject to competitive bidding. 27.701 Section 27.701 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive Bidding Procedures for the...

  7. 47 CFR 27.701 - 698-746 MHz bands subject to competitive bidding.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false 698-746 MHz bands subject to competitive bidding. 27.701 Section 27.701 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Competitive Bidding Procedures for the...

  8. 47 CFR 27.1222 - Operations in the 2568-2572 and 2614-2618 bands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Operations in the 2568-2572 and 2614-2618 bands. 27.1222 Section 27.1222 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Broadband Radio Service and...

  9. Enhancing the versatility of wireless biopotential acquisition for myoelectric prosthetic control

    NASA Astrophysics Data System (ADS)

    Bercich, Rebecca A.; Wang, Zhi; Mei, Henry; Hammer, Lauren H.; Seburn, Kevin L.; Hargrove, Levi J.; Irazoqui, Pedro P.

    2016-08-01

    Objective. A significant challenge in rehabilitating upper-limb amputees with sophisticated, electric-powered prostheses is sourcing reliable and independent channels of motor control information sufficient to precisely direct multiple degrees of freedom simultaneously. Approach. In response to the expressed needs of clinicians, we have developed a miniature, batteryless recording device that utilizes emerging integrated circuit technology and optimal impedance matching for magnetic resonantly coupled (MRC) wireless power transfer to improve the performance and versatility of wireless electrode interfaces with muscle. Main results. In this work we describe the fabrication and performance of a fully wireless and batteryless EMG recording system and use of this system to direct virtual and electric-powered limbs in real-time. The advantage of using MRC to optimize power transfer to a network of wireless devices is exhibited by EMG collected from an array of eight devices placed circumferentially around a human subject’s forearm. Significance. This is a comprehensive, low-cost, and non-proprietary solution that provides unprecedented versatility of configuration to direct myoelectric prostheses without wired connections to the body. The amenability of MRC to varied coil geometries and arrangements has the potential to improve the efficiency and robustness of wireless power transfer links at all levels of upper-limb amputation. Additionally, the wireless recording device’s programmable flash memory and selectable features will grant clinicians the unique ability to adapt and personalize the recording system’s functional protocol for patient- or algorithm-specific needs.

  10. Wireless Video System for Extra Vehicular Activity in the International Space Station and Space Shuttle Orbiter Environment

    NASA Technical Reports Server (NTRS)

    Loh, Yin C.; Boster, John; Hwu, Shian; Watson, John C.; deSilva, Kanishka; Piatek, Irene (Technical Monitor)

    1999-01-01

    The Wireless Video System (WVS) provides real-time video coverage of astronaut extra vehicular activities during International Space Station (ISS) assembly. The ISS wireless environment is unique due to the nature of the ISS structure and multiple RF interference sources. This paper describes how the system was developed to combat multipath, blockage, and interference using an automatic antenna switching system. Critical to system performance is the selection of receiver antenna installation locations determined using Uniform Geometrical Theory of Diffraction (GTD) techniques.

  11. Tunable Dielectric Materials and Devices for Broadband Wireless Communications

    NASA Technical Reports Server (NTRS)

    Mueller, Carl H.; Miranda, Felix A.; Dayton, James A. (Technical Monitor)

    1998-01-01

    Wireless and satellite communications are a rapidly growing industries which are slated for explosive growth into emerging countries as well as countries with advanced economies. The dominant trend in wireless communication systems is towards broadband applications such as multimedia file transfer, video transmission and Internet access. These applications require much higher data transmission rates than those currently used for voice transmission applications. To achieve these higher data rates, substantially larger bandwidths and higher carrier frequencies are required. A key roadblock to implementing these systems at K-band (18-26.5 GHz) and Ka-band (26.5-40 GHz) is the need to develop hardware which meets the requirements for high data rate transmission in a cost effective manner. In this chapter, we report on the status of tunable dielectric thin films for devices, such as resonators, filters, phased array antennas, and tunable oscillators, which utilize nonlinear tuning in the control elements. Paraelectric materials such as Barium Strontium Titanate ((Ba, Sr)TiO3) have dielectric constants which can be tuned by varying the magnitude of the electric field across the material. Therefore, these materials can be used to control the frequency and/or phase response of various devices such as electronically steerable phased array antennas, oscillators, and filters. Currently, tunable dielectric devices are being developed for applications which require high tunability, low loss, and good RF power-handling capabilities at microwave and millimeter-wave frequencies. These properties are strongly impacted by film microstructure and device design, and considerable developmental work is still required. However, in the last several years enormous progress has occurred in this field, validating the potential of tunable dielectric technology for broadband wireless communication applications. In this chapter we summarize how film processing techniques, microwave test

  12. Novel metamaterial based antennas for flexible wireless systems

    NASA Astrophysics Data System (ADS)

    Khaleel, Haider Raad

    Recent years have witnessed a great deal of interest from both academia and industry in the field of flexible electronic systems. This research topic tops the pyramid of research priorities requested by many national research agencies. Consistently, flexible electronic systems require the integration of flexible antennas operating in specific frequency bands to provide wireless connectivity which is highly demanded by today's information oriented society. On the other hand, metamaterials have become very popular in the design of contemporary antenna and microwave devices due to their wide range of applications derived from their unique properties which significantly enhances the performance of antennas and RF systems. Accordingly, the integration of metamaterial structures within flexible wireless systems is very beneficial in this growing field of research. A systematic approach to the analysis and design of flexible and conformal antennas and metamaterials is ultimately needed. The research reported in this thesis focuses on developing flexible low profile antennas and metamaterial structures in addition to characterizing their performance when integrated within flexible wireless systems. Three flexible, compact, and extremely low profile (50.8 microm) antennas intended for WLAN, Bluetooth and Ultra Wide Band (UWB) applications are presented. Next, a novel miniaturized Artificial Magnetic Conductor (AMC) and a new technique to enhance the bandwidth of micro-Negative (MNG) metamaterial are reported. Furthermore, the effect of bending on the AMC and MNG metamaterial is investigated in this thesis for the first time. Finally, the findings of this research are utilized in practical applications with specific design constraints including mutual coupling reduction between radiating elements in antenna arrays and MIMO systems and Specific Absorption Rate (SAR) reduction in telemedicine systems.

  13. A Scalable, Out-of-Band Diagnostics Architecture for International Space Station Systems Support

    NASA Technical Reports Server (NTRS)

    Fletcher, Daryl P.; Alena, Rick; Clancy, Daniel (Technical Monitor)

    2002-01-01

    The computational infrastructure of the International Space Station (ISS) is a dynamic system that supports multiple vehicle subsystems such as Caution and Warning, Electrical Power Systems and Command and Data Handling (C&DH), as well as scientific payloads of varying size and complexity. The dynamic nature of the ISS configuration coupled with the increased demand for payload support places a significant burden on the inherently resource constrained computational infrastructure of the ISS. Onboard system diagnostics applications are hosted on computers that are elements of the avionics network while ground-based diagnostic applications receive only a subset of available telemetry, down-linked via S-band communications. In this paper we propose a scalable, out-of-band diagnostics architecture for ISS systems support that uses a read-only connection for C&DH data acquisition, which provides a lower cost of deployment and maintenance (versus a higher criticality readwrite connection). The diagnostics processing burden is off-loaded from the avionics network to elements of the on-board LAN that have a lower overall cost of operation and increased computational capacity. A superset of diagnostic data, richer in content than the configured telemetry, is made available to Advanced Diagnostic System (ADS) clients running on wireless handheld devices, affording the crew greater mobility for troubleshooting and providing improved insight into vehicle state. The superset of diagnostic data is made available to the ground in near real-time via an out-of band downlink, providing a high level of fidelity between vehicle state and test, training and operational facilities on the ground.

  14. Identification of the UIR bands

    NASA Astrophysics Data System (ADS)

    Johnson, Fred M.

    2016-06-01

    Starlight undergoing multiple scattering processes within fluffy grains results in extinction, UV 2175A bump, DIBs and the UIR bands. Spectroscopic lab and DIB data has identified the highly fluorescent molecule Dipyridyl Magnesium Tetrabenzoporphyrin (MgTBP). Reflection and Raman scattering experimental data will be presented which designates this molecule as the primary source for UIR signals. MgTBP sublimes at about 500OC. It is produced via high temperature plasma synthesis within and subsequently ejected from comets which in turn are by-products of solar system-planetary development. Interstellar dust is the left-over refuse which implies prodigious solar system evolution in each galaxy.

  15. A fully integrated wireless system for intracranial direct cortical stimulation, real-time electrocorticography data transmission, and smart cage for wireless battery recharge.

    PubMed

    Piangerelli, Marco; Ciavarro, Marco; Paris, Antonino; Marchetti, Stefano; Cristiani, Paolo; Puttilli, Cosimo; Torres, Napoleon; Benabid, Alim Louis; Romanelli, Pantaleo

    2014-01-01

    Wireless transmission of cortical signals is an essential step to improve the safety of epilepsy procedures requiring seizure focus localization and to provide chronic recording of brain activity for Brain Computer Interface (BCI) applications. Our group developed a fully implantable and externally rechargeable device, able to provide wireless electrocorticographic (ECoG) recording and cortical stimulation (CS). The first prototype of a wireless multi-channel very low power ECoG system was custom-designed to be implanted on non-human primates. The device, named ECOGIW-16E, is housed in a compact hermetically sealed Polyether ether ketone (PEEK) enclosure, allowing seamless battery recharge. ECOGIW-16E is recharged in a wireless fashion using a special cage designed to facilitate the recharge process in monkeys and developed in accordance with guidelines for accommodation of animals by Council of Europe (ETS123). The inductively recharging cage is made up of nylon and provides a thoroughly novel experimental setting on freely moving animals. The combination of wireless cable-free ECoG and external seamless battery recharge solves the problems and shortcomings caused by the presence of cables leaving the skull, providing a safer and easier way to monitor patients and to perform ECoG recording on primates. Data transmission exploits the newly available Medical Implant Communication Service band (MICS): 402-405 MHz. ECOGIW-16E was implanted over the left sensorimotor cortex of a macaca fascicularis to assess the feasibility of wireless ECoG monitoring and brain mapping through CS. With this device, we were able to record the everyday life ECoG signal from a monkey and to deliver focal brain stimulation with movement elicitation.

  16. A fully integrated wireless system for intracranial direct cortical stimulation, real-time electrocorticography data transmission, and smart cage for wireless battery recharge.

    PubMed

    Piangerelli, Marco; Ciavarro, Marco; Paris, Antonino; Marchetti, Stefano; Cristiani, Paolo; Puttilli, Cosimo; Torres, Napoleon; Benabid, Alim Louis; Romanelli, Pantaleo

    2014-01-01

    Wireless transmission of cortical signals is an essential step to improve the safety of epilepsy procedures requiring seizure focus localization and to provide chronic recording of brain activity for Brain Computer Interface (BCI) applications. Our group developed a fully implantable and externally rechargeable device, able to provide wireless electrocorticographic (ECoG) recording and cortical stimulation (CS). The first prototype of a wireless multi-channel very low power ECoG system was custom-designed to be implanted on non-human primates. The device, named ECOGIW-16E, is housed in a compact hermetically sealed Polyether ether ketone (PEEK) enclosure, allowing seamless battery recharge. ECOGIW-16E is recharged in a wireless fashion using a special cage designed to facilitate the recharge process in monkeys and developed in accordance with guidelines for accommodation of animals by Council of Europe (ETS123). The inductively recharging cage is made up of nylon and provides a thoroughly novel experimental setting on freely moving animals. The combination of wireless cable-free ECoG and external seamless battery recharge solves the problems and shortcomings caused by the presence of cables leaving the skull, providing a safer and easier way to monitor patients and to perform ECoG recording on primates. Data transmission exploits the newly available Medical Implant Communication Service band (MICS): 402-405 MHz. ECOGIW-16E was implanted over the left sensorimotor cortex of a macaca fascicularis to assess the feasibility of wireless ECoG monitoring and brain mapping through CS. With this device, we were able to record the everyday life ECoG signal from a monkey and to deliver focal brain stimulation with movement elicitation. PMID:25202300

  17. A Fully Integrated Wireless System for Intracranial Direct Cortical Stimulation, Real-Time Electrocorticography Data Transmission, and Smart Cage for Wireless Battery Recharge

    PubMed Central

    Piangerelli, Marco; Ciavarro, Marco; Paris, Antonino; Marchetti, Stefano; Cristiani, Paolo; Puttilli, Cosimo; Torres, Napoleon; Benabid, Alim Louis; Romanelli, Pantaleo

    2014-01-01

    Wireless transmission of cortical signals is an essential step to improve the safety of epilepsy procedures requiring seizure focus localization and to provide chronic recording of brain activity for Brain Computer Interface (BCI) applications. Our group developed a fully implantable and externally rechargeable device, able to provide wireless electrocorticographic (ECoG) recording and cortical stimulation (CS). The first prototype of a wireless multi-channel very low power ECoG system was custom-designed to be implanted on non-human primates. The device, named ECOGIW-16E, is housed in a compact hermetically sealed Polyether ether ketone (PEEK) enclosure, allowing seamless battery recharge. ECOGIW-16E is recharged in a wireless fashion using a special cage designed to facilitate the recharge process in monkeys and developed in accordance with guidelines for accommodation of animals by Council of Europe (ETS123). The inductively recharging cage is made up of nylon and provides a thoroughly novel experimental setting on freely moving animals. The combination of wireless cable-free ECoG and external seamless battery recharge solves the problems and shortcomings caused by the presence of cables leaving the skull, providing a safer and easier way to monitor patients and to perform ECoG recording on primates. Data transmission exploits the newly available Medical Implant Communication Service band (MICS): 402–405 MHz. ECOGIW-16E was implanted over the left sensorimotor cortex of a macaca fascicularis to assess the feasibility of wireless ECoG monitoring and brain mapping through CS. With this device, we were able to record the everyday life ECoG signal from a monkey and to deliver focal brain stimulation with movement elicitation. PMID:25202300

  18. Performance Analysis of IIUM Wireless Campus Network

    NASA Astrophysics Data System (ADS)

    Abd Latif, Suhaimi; Masud, Mosharrof H.; Anwar, Farhat

    2013-12-01

    International Islamic University Malaysia (IIUM) is one of the leading universities in the world in terms of quality of education that has been achieved due to providing numerous facilities including wireless services to every enrolled student. The quality of this wireless service is controlled and monitored by Information Technology Division (ITD), an ISO standardized organization under the university. This paper aims to investigate the constraints of wireless campus network of IIUM. It evaluates the performance of the IIUM wireless campus network in terms of delay, throughput and jitter. QualNet 5.2 simulator tool has employed to measure these performances of IIUM wireless campus network. The observation from the simulation result could be one of the influencing factors in improving wireless services for ITD and further improvement.

  19. 75 FR 43206 - In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... COMMISSION In the Matter of Certain Wireless Communications System Server Software, Wireless Handheld Devices... communications system server software, wireless handheld devices and battery packs by reason of infringement of..., 2010, based on a complaint filed by Motorola, Inc. (``Motorola'') of Schaumburg, Illinois. 75 FR...

  20. Preoperative information management system using wireless PDAs.

    PubMed

    Sawa, Tomohiro; Okahara, Masaharu; Santo, Masayuki; Schmidt, Ulrich; Nakata, Yoshinori; Morita, Shigeho; Ohno-Machado, Lucila

    2003-01-01

    Personal Digital Assistant (PDA) and wireless communication are currently available in clinical settings. We developed wireless PDA software that assists anesthesiologists in pre-operative patient assessment. The device communicates with the hospital information system through a wireless LAN and is equipped with pre-programmed data entry templates for pre-operative assessment. As a preliminary test of the device, we randomly assigned residents in preoperative assessment to an intervention and a control arm and compared the results.

  1. Wireless Sensor Needs Defined by SBIR Topics

    NASA Technical Reports Server (NTRS)

    Studor, George F.

    2010-01-01

    This slide presentation reviews the needs for wireless sensor technology from various U.S. government agencies as exhibited by an analysis of Small Business Innovation Research (SBIR) solicitations. It would appear that a multi-agency group looking at overlapping wireless sensor needs and technology projects is desired. Included in this presentation is a review of the NASA SBIR process, and an examination of some of the SBIR projects from NASA, and other agencies that involve wireless sensor development

  2. Hybrid power for wireless sensors

    NASA Astrophysics Data System (ADS)

    Lakeman, Charles D. E.; Fleig, Patrick F.; DeGreeff, Jenniffer L.; Trainor, J. Timothy

    2006-05-01

    Wireless sensors provide solutions to otherwise intractable problems in homeland defense and security, building automation, industrial process monitoring and control, structural health monitoring in bridges, aircraft, buildings and ships and a host of applications where the cost or feasibility of deploying wired sensors is impractical. The biggest challenge facing wireless sensors is power. While advances in power management and battery technology may enable 3 to 5 year battery life, in many applications even this is not sufficient. Energy harvesting techniques show potential to provide long lasting power, but suffer from low power density values, meaning that they must be oversized to deliver power for short duty cycle communications functions. In this paper we demonstrate a solution that draws on the benefits of energy harvesting for long life, and microbatteries and microsupercapacitors to provide back-up and pulse power capabilities without the need for refueling or recharging.

  3. Biomedical Wireless Ambulatory Crew Monitor

    NASA Technical Reports Server (NTRS)

    Chmiel, Alan; Humphreys, Brad

    2009-01-01

    A compact, ambulatory biometric data acquisition system has been developed for space and commercial terrestrial use. BioWATCH (Bio medical Wireless and Ambulatory Telemetry for Crew Health) acquires signals from biomedical sensors using acquisition modules attached to a common data and power bus. Several slots allow the user to configure the unit by inserting sensor-specific modules. The data are then sent real-time from the unit over any commercially implemented wireless network including 802.11b/g, WCDMA, 3G. This system has a distributed computing hierarchy and has a common data controller on each sensor module. This allows for the modularity of the device along with the tailored ability to control the cards using a relatively small master processor. The distributed nature of this system affords the modularity, size, and power consumption that betters the current state of the art in medical ambulatory data acquisition. A new company was created to market this technology.

  4. Wireless autonomous device data transmission

    NASA Technical Reports Server (NTRS)

    Sammel, Jr., David W. (Inventor); Cain, James T. (Inventor); Mickle, Marlin H. (Inventor); Mi, Minhong (Inventor)

    2013-01-01

    A method of communicating information from a wireless autonomous device (WAD) to a base station. The WAD has a data element having a predetermined profile having a total number of sequenced possible data element combinations. The method includes receiving at the WAD an RF profile transmitted by the base station that includes a triggering portion having a number of pulses, wherein the number is at least equal to the total number of possible data element combinations. The method further includes keeping a count of received pulses and wirelessly transmitting a piece of data, preferably one bit, to the base station when the count reaches a value equal to the stored data element's particular number in the sequence. Finally, the method includes receiving the piece of data at the base station and using the receipt thereof to determine which of the possible data element combinations the stored data element is.

  5. Wireless augmented reality communication system

    NASA Technical Reports Server (NTRS)

    Devereaux, Ann (Inventor); Jedrey, Thomas (Inventor); Agan, Martin (Inventor)

    2006-01-01

    The system of the present invention is a highly integrated radio communication system with a multimedia co-processor which allows true two-way multimedia (video, audio, data) access as well as real-time biomedical monitoring in a pager-sized portable access unit. The system is integrated in a network structure including one or more general purpose nodes for providing a wireless-to-wired interface. The network architecture allows video, audio and data (including biomedical data) streams to be connected directly to external users and devices. The portable access units may also be mated to various non-personal devices such as cameras or environmental sensors for providing a method for setting up wireless sensor nets from which reported data may be accessed through the portable access unit. The reported data may alternatively be automatically logged at a remote computer for access and viewing through a portable access unit, including the user's own.

  6. Self-Powered Wireless Sensors

    NASA Technical Reports Server (NTRS)

    Dynys, Fred; Sayir, Ali

    2008-01-01

    NASA's integrated vehicle health management (IVHM) program offers the potential to improve aeronautical safety, reduce cost and improve performance by utilizing networks of wireless sensors. Development of sensor systems for engine hot sections will provide real-time data for prognostics and health management of turbo-engines. Sustainable power to embedded wireless sensors is a key challenge for prolong operation. Harvesting energy from the environment has emerged as a viable technique for power generation. Thermoelectric generators provide a direct conversion of heat energy to electrical energy. Micro-power sources derived from thermoelectric films are desired for applications in harsh thermal environments. Silicon based alloys are being explored for applications in high temperature environments containing oxygen. Chromium based p-type Si/Ge alloys exhibit Seebeck coefficients on the order of 160 micro V/K and low thermal conductance of 2.5 to 5 W/mK. Thermoelectric properties of bulk and thin film silicides will be discussed

  7. Wireless Augmented Reality Communication System

    NASA Technical Reports Server (NTRS)

    Devereaux, Ann (Inventor); Jedrey, Thomas (Inventor); Agan, Martin (Inventor)

    2016-01-01

    The system of the present invention is a highly integrated radio communication system with a multimedia co-processor which allows true two-way multimedia (video, audio, data) access as well as real-time biomedical monitoring in a pager-sized portable access unit. The system is integrated in a network structure including one or more general purpose nodes for providing a wireless-to-wired interface. The network architecture allows video, audio and data (including biomedical data) streams to be connected directly to external users and devices. The portable access units may also be mated to various non-personal devices such as cameras or environmental sensors for providing a method for setting up wireless sensor nets from which reported data may be accessed through the portable access unit. The reported data may alternatively be automatically logged at a remote computer for access and viewing through a portable access unit, including the user's own.

  8. Wireless magnetothermal deep brain stimulation.

    PubMed

    Chen, Ritchie; Romero, Gabriela; Christiansen, Michael G; Mohr, Alan; Anikeeva, Polina

    2015-03-27

    Wireless deep brain stimulation of well-defined neuronal populations could facilitate the study of intact brain circuits and the treatment of neurological disorders. Here, we demonstrate minimally invasive and remote neural excitation through the activation of the heat-sensitive capsaicin receptor TRPV1 by magnetic nanoparticles. When exposed to alternating magnetic fields, the nanoparticles dissipate heat generated by hysteresis, triggering widespread and reversible firing of TRPV1(+) neurons. Wireless magnetothermal stimulation in the ventral tegmental area of mice evoked excitation in subpopulations of neurons in the targeted brain region and in structures receiving excitatory projections. The nanoparticles persisted in the brain for over a month, allowing for chronic stimulation without the need for implants and connectors. PMID:25765068

  9. Wireless Augmented Reality Communication System

    NASA Technical Reports Server (NTRS)

    Devereaux, Ann (Inventor); Jedrey, Thomas (Inventor); Agan, Martin (Inventor)

    2014-01-01

    The system of the present invention is a highly integrated radio communication system with a multimedia co-processor which allows true two-way multimedia (video, audio, data) access as well as real-time biomedical monitoring in a pager-sized portable access unit. The system is integrated in a network structure including one or more general purpose nodes for providing a wireless-to-wired interface. The network architecture allows video, audio and data (including biomedical data) streams to be connected directly to external users and devices. The portable access units may also be mated to various non-personal devices such as cameras or environmental sensors for providing a method for setting up wireless sensor nets from which reported data may be accessed through the portable access unit. The reported data may alternatively be automatically logged at a remote computer for access and viewing through a portable access unit, including the user's own.

  10. Long-Range Wireless Mesh Network for Weather Monitoring in Unfriendly Geographic Conditions

    PubMed Central

    Toledano-Ayala, Manuel; Herrera-Ruiz, Gilberto; Soto-Zarazúa, Genaro M.; Rivas-Araiza, Edgar A.; Bazán Trujillo, Rey D.; Porrás-Trejo, Rafael E.

    2011-01-01

    In this paper a long-range wireless mesh network system is presented. It consists of three main parts: Remote Terminal Units (RTUs), Base Terminal Units (BTUs) and a Central Server (CS). The RTUs share a wireless network transmitting in the industrial, scientific and medical applications ISM band, which reaches up to 64 Km in a single point-to-point communication. A BTU controls the traffic within the network and has as its main task interconnecting it to a Ku-band satellite link using an embedded microcontroller-based gateway. Collected data is stored in a CS and presented to the final user in a numerical and a graphical form in a web portal. PMID:22164008

  11. Wireless communication devices and movement monitoring methods

    DOEpatents

    Skorpik, James R.

    2006-10-31

    Wireless communication devices and movement monitoring methods are described. In one aspect, a wireless communication device includes a housing, wireless communication circuitry coupled with the housing and configured to communicate wireless signals, movement circuitry coupled with the housing and configured to provide movement data regarding movement sensed by the movement circuitry, and event processing circuitry coupled with the housing and the movement circuitry, wherein the event processing circuitry is configured to process the movement data, and wherein at least a portion of the event processing circuitry is configured to operate in a first operational state having a different power consumption rate compared with a second operational state.

  12. Space Shuttle Wireless Crew Communications

    NASA Technical Reports Server (NTRS)

    Armstrong, R. W.; Doe, R. A.

    1982-01-01

    The design, development, and performance characteristics of the Space Shuttle's Wireless Crew Communications System are discussed. This system allows Space Shuttle crews to interface with the onboard audio distribution system without the need for communications umbilicals, and has been designed through the adaptation of commercially available hardware in order to minimize development time. Testing aboard the Space Shuttle Orbiter Columbia has revealed no failures or design deficiencies.

  13. InGaAsP/AlGaAs multiple-wavelength vertical-cavity lasers and arrays in the 1.5-μm band fabricated by localized wafer fusion technique

    NASA Astrophysics Data System (ADS)

    Syrbu, Alexei V.; Iakovlev, Vladimir P.; Rudra, Alok P.; Berseth, Claude-Albert; Kapon, Eli E.; Mereuta, Alexandru Z.; Sagnes, Isabelle; Ougazzaden, Abdallah

    2000-02-01

    We have demonstrated InGaAsP/AlGaAs double fused 1.5 micrometers multiple wavelength vertical cavity lasers and arrays in which element definition is obtained by localized fusion. Laser elements emit in continuous wave under electrical and optical pumping. Multiple wavelength single element VCSELs have been fabricated in the same batch taking advantage of layer thickness nonuniformity of InGaAsP/InP material close to the edge of the wafer. To obtain multiple wavelength arrays a controllable cavity length variation using anodic oxidation has been performed. The wavelength span in an 8 by 1 laser array is 10 nm. Single mode operation with more than of 40 dB side mode suppression ratio is characteristic for laser elements in the array.

  14. Development of a Wireless Displacement Measurement System Using Acceleration Responses

    PubMed Central

    Park, Jong-Woong; Sim, Sung-Han; Jung, Hyung-Jo; Spencer, Billie F.

    2013-01-01

    Displacement measurements are useful information for various engineering applications such as structural health monitoring (SHM), earthquake engineering and system identification. Most existing displacement measurement methods are costly, labor-intensive, and have difficulties particularly when applying to full-scale civil structures because the methods require stationary reference points. Indirect estimation methods converting acceleration to displacement can be a good alternative as acceleration transducers are generally cost-effective, easy to install, and have low noise. However, the application of acceleration-based methods to full-scale civil structures such as long span bridges is challenging due to the need to install cables to connect the sensors to a base station. This article proposes a low-cost wireless displacement measurement system using acceleration. Developed with smart sensors that are low-cost, wireless, and capable of on-board computation, the wireless displacement measurement system has significant potential to impact many applications that need displacement information at multiple locations of a structure. The system implements an FIR-filter type displacement estimation algorithm that can remove low frequency drifts typically caused by numerical integration of discrete acceleration signals. To verify the accuracy and feasibility of the proposed system, laboratory tests are carried out using a shaking table and on a three storey shear building model, experimentally confirming the effectiveness of the proposed system. PMID:23881123

  15. Wireless design of a multisensor system for physical activity monitoring.

    PubMed

    Mo, Lingfei; Liu, Shaopeng; Gao, Robert X; John, Dinesh; Staudenmayer, John W; Freedson, Patty S

    2012-11-01

    Real-time monitoring of human physical activity (PA) is important for assessing the intensity of activity and exposure to environmental pollutions. A wireless wearable multisenor integrated measurement system (WIMS) has been designed for real-time measurement of the energy expenditure and breathing volume of human subjects under free-living conditions. To address challenges posted by the limited battery life and data synchronization requirement among multiple sensors in the system, the ZigBee communication platform has been explored for energy-efficient design. Two algorithms have been developed (multiData packaging and slot-data-synchronization) and coded into a microcontroller (MCU)-based sensor circuitry for real-time control of wireless data communication. Experiments have shown that the design enables continued operation of the wearable system for up to 68 h, with the maximum error for data synchronization among the various sensor nodes (SNs) being less than 24 ms. Experiment under free-living conditions have shown that the WIMS is able to correctly recognize the activity intensity level 86% of the time. The results demonstrate the effectiveness of the energy-efficient wireless design for human PA monitoring.

  16. Common MD-IS infrastructure for wireless data technologies

    NASA Astrophysics Data System (ADS)

    White, Malcolm E.

    1995-12-01

    The expansion of global networks, caused by growth and acquisition within the commercial sector, is forcing users to move away from proprietary systems in favor of standards-based, open systems architectures. The same is true in the wireless data communications arena, where operators of proprietary wireless data networks have endeavored to convince users that their particular implementation provides the best service. However, most of the vendors touting these solutions have failed to gain the critical mass that might have lead to their technologies' adoption as a defacto standard, and have been held back by a lack of applications and the high cost of mobile devices. The advent of the cellular digital packet data (CDPD) specification and its support by much of the public cellular service industry has set the stage for the ubiquitous coverage of wireless packet data services across the Unites States. Although CDPD was developed for operation over the advanced mobile phone system (AMPS) cellular network, many of the defined protocols are industry standards that can be applied to the construction of a common infrastructure supporting multiple airlink standards. This approach offers overall cost savings and operation efficiency for service providers, hardware, and software developers and end-users alike, and could be equally advantageous for those service operators using proprietary end system protocols, should they wish to migrate towards an open standard.

  17. On-Wafer Characterization of Millimeter-Wave Antennas for Wireless Applications

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Lee, Richard Q.

    1998-01-01

    The paper demonstrates a de-embedding technique and a direct on-substrate measurement technique for fast and inexpensive characterization of miniature antennas for wireless applications at millimeter-wave frequencies. The technique is demonstrated by measurements on a tapered slot antenna (TSA). The measured results at Ka-Band frequencies include input impedance, mutual coupling between two TSAs and absolute gain of TSA.

  18. Stretch Band Exercise Program

    ERIC Educational Resources Information Center

    Skirka, Nicholas; Hume, Donald

    2007-01-01

    This article discusses how to use stretch bands for improving total body fitness and quality of life. A stretch band exercise program offers a versatile and inexpensive option to motivate participants to exercise. The authors suggest practical exercises that can be used in physical education to improve or maintain muscular strength and endurance,…

  19. Rubber Band Science

    ERIC Educational Resources Information Center

    Cowens, John

    2005-01-01

    Not only are rubber bands great for binding objects together, but they can be used in a simple science experiment that involves predicting, problem solving, measuring, graphing, and experimenting. In this article, the author describes how rubber bands can be used to teach the force of mass.

  20. Singing with the Band

    ERIC Educational Resources Information Center

    Altman, Timothy Meyer; Wright, Gary K.

    2012-01-01

    Usually band, orchestra, and choir directors work independently. However, the authors--one a choral director, the other a band director--have learned that making music together makes friends. Not only can ensemble directors get along, but joint concerts may be just the way to help students see how music can reach the heart. Combined instrumental…

  1. Progressive Band Selection

    NASA Technical Reports Server (NTRS)

    Fisher, Kevin; Chang, Chein-I

    2009-01-01

    Progressive band selection (PBS) reduces spectral redundancy without significant loss of information, thereby reducing hyperspectral image data volume and processing time. Used onboard a spacecraft, it can also reduce image downlink time. PBS prioritizes an image's spectral bands according to priority scores that measure their significance to a specific application. Then it uses one of three methods to select an appropriate number of the most useful bands. Key challenges for PBS include selecting an appropriate criterion to generate band priority scores, and determining how many bands should be retained in the reduced image. The image's Virtual Dimensionality (VD), once computed, is a reasonable estimate of the latter. We describe the major design details of PBS and test PBS in a land classification experiment.

  2. TCPL: A Defense against wormhole attacks in wireless sensor networks

    NASA Astrophysics Data System (ADS)

    Kumar, K. E. Naresh; Waheed, Mohd. Abdul; Basappa, K. Kari

    2010-10-01

    Do In this paper presents recent advances in technology have made low-cost, low-power wireless sensors with efficient energy consumption. A network of such nodes can coordinate among themselves for distributed sensing and processing of certain data. For which, we propose an architecture to provide a stateless solution in sensor networks for efficient routing in wireless sensor networks. This type of architecture is known as Tree Cast. We propose a unique method of address allocation, building up multiple disjoint trees which are geographically inter-twined and rooted at the data sink. Using these trees, routing messages to and from the sink node without maintaining any routing state in the sensor nodes is possible. In this paper, we introduce the wormhole attack, a severe attack in ad hoc networks that is particularly challenging to defend against. The wormhole attack is possible even if the attacker has not compromised any hosts and even if all communication provides authenticity and confidentiality. In the wormhole attack, an attacker records packets (or bits) at one location in the network, tunnels them to another location, and retransmits them there into the network. The wormhole attack can form a serious threat in wireless networks, especially against many sensor network routing protocols and location-based wireless security systems. For example, most existing ad hoc network routing protocols, without some mechanism to defend against the wormhole attack, would be unable to find routes longer than one or two hops, severely disrupting communication. We present a new, general mechanism, called packet leashes, for detecting and thus defending against wormhole attacks, and we present a specific protocol, called TIK, that implements leashes.

  3. TCPL: A Defense against wormhole attacks in wireless sensor networks

    SciTech Connect

    Kumar, K. E. Naresh; Waheed, Mohd. Abdul; Basappa, K. Kari

    2010-10-26

    Do In this paper presents recent advances in technology have made low-cost, low-power wireless sensors with efficient energy consumption. A network of such nodes can coordinate among themselves for distributed sensing and processing of certain data. For which, we propose an architecture to provide a stateless solution in sensor networks for efficient routing in wireless sensor networks. This type of architecture is known as Tree Cast. We propose a unique method of address allocation, building up multiple disjoint trees which are geographically inter-twined and rooted at the data sink. Using these trees, routing messages to and from the sink node without maintaining any routing state in the sensor nodes is possible. In this paper, we introduce the wormhole attack, a severe attack in ad hoc networks that is particularly challenging to defend against. The wormhole attack is possible even if the attacker has not compromised any hosts and even if all communication provides authenticity and confidentiality. In the wormhole attack, an attacker records packets (or bits) at one location in the network, tunnels them to another location, and retransmits them there into the network. The wormhole attack can form a serious threat in wireless networks, especially against many sensor network routing protocols and location-based wireless security systems. For example, most existing ad hoc network routing protocols, without some mechanism to defend against the wormhole attack, would be unable to find routes longer than one or two hops, severely disrupting communication. We present a new, general mechanism, called packet leashes, for detecting and thus defending against wormhole attacks, and we present a specific protocol, called TIK, that implements leashes.

  4. Reconfigurable antenna options for 2.45/5 GHz wireless body area networks in healthcare applications.

    PubMed

    Abbas, Syed Muzahir; Ranga, Yogesh; Esselle, Karu P

    2015-01-01

    This paper presents electronically reconfigurable antenna options in healthcare applications. They are suitable for wireless body area network devices operating in the industrial, scientific, and medical (ISM) band at 2.45 GHz and IEEE 802.11 Wireless Local Area Network (WLAN) band at 5 GHz (5.15-5.35 GHz, 5.25-5.35 GHz). Two types of antennas are investigated: Antenna-I has a full ground plane and Antenna-II has a partial ground plane. The proposed antennas provide ISM operation in one mode while in another mode they support 5 GHz WLAN band. Their performance is assessed for body centric wireless communication using a simplified human body model. Antenna sensitivity to the gap between the antenna and the human body is investigated for both modes of each antenna. The proposed antennas exhibit a wide radiation pattern along the body surface to provide wide coverage and their small width (14 mm) makes them suitable for on-body communication in healthcare applications. PMID:26737528

  5. Reconfigurable antenna options for 2.45/5 GHz wireless body area networks in healthcare applications.

    PubMed

    Abbas, Syed Muzahir; Ranga, Yogesh; Esselle, Karu P

    2015-01-01

    This paper presents electronically reconfigurable antenna options in healthcare applications. They are suitable for wireless body area network devices operating in the industrial, scientific, and medical (ISM) band at 2.45 GHz and IEEE 802.11 Wireless Local Area Network (WLAN) band at 5 GHz (5.15-5.35 GHz, 5.25-5.35 GHz). Two types of antennas are investigated: Antenna-I has a full ground plane and Antenna-II has a partial ground plane. The proposed antennas provide ISM operation in one mode while in another mode they support 5 GHz WLAN band. Their performance is assessed for body centric wireless communication using a simplified human body model. Antenna sensitivity to the gap between the antenna and the human body is investigated for both modes of each antenna. The proposed antennas exhibit a wide radiation pattern along the body surface to provide wide coverage and their small width (14 mm) makes them suitable for on-body communication in healthcare applications.

  6. Wireless Temperature-Monitoring System

    NASA Technical Reports Server (NTRS)

    Solano, Wanda

    2003-01-01

    A relatively inexpensive instrumentation system that includes units that are connected to thermocouples and that are parts of a radio-communication network has been developed to enable monitoring of temperatures at multiple locations. Because there is no need to string wires or cables for communication, the system is well suited for monitoring temperatures at remote locations and for applications in which frequent changes of monitored or monitoring locations are needed. The system can also be adapted to monitoring of slowly varying physical quantities, other than temperature, that can be transduced by solid-state electronic sensors. The system comprises any number of transmitting units and a single receiving unit (see figure). Each transmitting unit includes connections for as many as four external thermocouples, a signal-conditioning module, a control module, and a radio-communication module. The signal- conditioning module acts as an interface between the thermocouples and the rest of the transmitting unit and includes a built-in solid ambient-temperature sensor that is in addition to the external thermocouples. The control module is a "system-on-chip" embedded processor that includes analog-to-digital converters, serial and parallel data ports, and an interface for local connection to an analog meter that is used during installation to verify correct operation. The radio-communication module contains a commercial spread-spectrum transceiver that operates in the 900-MHz industrial, scientific, and medical (ISM) frequency band. This transceiver transmits data to the receiving unit at a rate of 19,200 baud. The receiving unit includes a transceiver like that of a transmitting unit, plus a control module that contains a system-on-chip processor that includes serial data port for output to a computer that runs monitoring and/or control software, a parallel data port for output to a printer, and a seven-segment light-emitting-diode display.

  7. 146-GHz millimeter-wave radio-over-fiber photonic wireless transmission system.

    PubMed

    Fice, M J; Rouvalis, E; van Dijk, F; Accard, A; Lelarge, F; Renaud, C C; Carpintero, G; Seeds, A J

    2012-01-16

    We report the experimental implementation of a wireless transmission system with a 146-GHz carrier frequency which is generated by optical heterodyning the two modes from a monolithically integrated quantum dash dual-DFB source. The monolithic structure of the device and the inherent low noise characteristics of quantum dash gain material allow us to demonstrate the transmission of a 1 Gbps ON-OFF keyed data signal with the two wavelengths in a free-running state at 146-GHz carrier wave frequency. The tuning range of the device fully covers the W-band (75 - 110 GHz) and the F-band (90 - 140 GHz).

  8. Wireless power transfer to a cardiac implant

    NASA Astrophysics Data System (ADS)

    Kim, Sanghoek; Ho, John S.; Chen, Lisa Y.; Poon, Ada S. Y.

    2012-08-01

    We analyze wireless power transfer between a source and a weakly coupled implant on the heart. Numerical studies show that mid-field wireless powering achieves much higher power transfer efficiency than traditional inductively coupled systems. With proper system design, power sufficient to operate typical cardiac implants can be received by millimeter-sized coils.

  9. Tips for Implementing a Wireless Network

    ERIC Educational Resources Information Center

    Walery, Darrell

    2005-01-01

    This article provides a quick start guide to provide educators with the basic points to consider before installing a wireless network in the school. Since many school districts have already implemented wireless networks, there is a lot of information available online to assist in the process.

  10. Home and School Technology: Wired versus Wireless.

    ERIC Educational Resources Information Center

    Van Horn, Royal

    2001-01-01

    Presents results of informal research on smart homes and appliances, structured home wiring, whole-house audio/video distribution, hybrid cable, and wireless networks. Computer network wiring is tricky to install unless all-in-one jacketed cable is used. Wireless phones help installers avoid pre-wiring problems in homes and schools. (MLH)

  11. Wireless Laptops and Local Area Networks.

    ERIC Educational Resources Information Center

    Tolson, Stephanie Diane

    2001-01-01

    Describes experiences at St. Louis Community College at Florissant Valley (Missouri) with the use of wireless technology and a local area network for library bibliographic instruction. Discusses faculty input and attitudes; technical challenges; and experiences at other community colleges that have found wireless connections more economical than…

  12. Iliotibial band friction syndrome.

    PubMed

    Lavine, Ronald

    2010-07-20

    Published articles on iliotibial band friction syndrome have been reviewed. These articles cover the epidemiology, etiology, anatomy, pathology, prevention, and treatment of the condition. This article describes (1) the various etiological models that have been proposed to explain iliotibial band friction syndrome; (2) some of the imaging methods, research studies, and clinical experiences that support or call into question these various models; (3) commonly proposed treatment methods for iliotibial band friction syndrome; and (4) the rationale behind these methods and the clinical outcome studies that support their efficacy.

  13. Chiral Bands and Triaxiality

    SciTech Connect

    Petrache, C.M.

    2004-02-27

    The results obtained with the GASP array in the A=130 mass region are reviewed, emphasizing the discovery excited highly-deformed bands and their decay out, the study of the odd-odd Pr nuclei up to high spins, the discovery of stable triaxial bands in Nd nuclei close to the N=82 shell closure. The very recent studies of nuclei near the proton drip line are described. A discussion of the origin of the various doublet bands observed in odd-odd nuclei of the A=130 mass region is presented.

  14. Iliotibial band friction syndrome

    PubMed Central

    2010-01-01

    Published articles on iliotibial band friction syndrome have been reviewed. These articles cover the epidemiology, etiology, anatomy, pathology, prevention, and treatment of the condition. This article describes (1) the various etiological models that have been proposed to explain iliotibial band friction syndrome; (2) some of the imaging methods, research studies, and clinical experiences that support or call into question these various models; (3) commonly proposed treatment methods for iliotibial band friction syndrome; and (4) the rationale behind these methods and the clinical outcome studies that support their efficacy. PMID:21063495

  15. Tremor bands sweep Cascadia

    NASA Astrophysics Data System (ADS)

    Ghosh, A.; Vidale, J. E.; Sweet, J. R.; Creager, K. C.; Wech, A.; Houston, H.

    2009-12-01

    In the last few years, the spatiotemporal distribution of non-volcanic tremor (NVT) activity has been watched with intense curiosity in Cascadia, Japan, and San Andreas Fault. During an episodic tremor and slip (ETS) event in the Cascadia Subduction Zone (CSZ), the dominant tremor migration pattern is characterized by along-strike marching of tremor at a rate of 10 km/day. Spatiotemporal evolution gives critical clues on the physical mechanism of NVT, and the evolving state of stress in the fault. However, tremor migration, its variations over different time-scales, and its underlying physics remain poorly understood. We recorded the May 2008 ETS event in Cascadia with a dense small-aperture seismic array, and beamformed to detect and locate tremor with unparalleled resolution [Ghosh et al., GRL, 2009]. The beams reveal that tremor occurs in elongated bands that extend ~50 km in the direction parallel to the convergence of CSZ and only 10-15 km in the along-strike direction. This is in contrast to the wider blobs of tremor locations seen using a conventional envelope cross-correlation method. The peak activities of the tremor bands are well separated in space and time. Each band remains active for a good part of a day, and fades away while the adjacent band is slowly peaking up. During the 2008 ETS event, these convergence-parallel tremor bands swept the Cascadia megathrust from SE to NW in the region most clearly imaged by our array, producing the long-term tremor migration. Embedded within the bands lie long streaks of tremor that show steady and rapid migration on time-scales of several minutes to an hour at velocities of several tens of km/hr. These tremor streaks also propagate mostly convergence-parallel, along a particular band, both up- and down-dip. The elongated shape of the tremor bands may cause by the tendency of the tremor streaks to align parallel to the direction of subduction. We propose that each tremor band is the result of failure of a section

  16. Dynamic interrogation of wireless antenna sensor

    NASA Astrophysics Data System (ADS)

    Yao, J.; Tjuatja, S.; Huang, H.; Sanders, J.

    2014-03-01

    This paper presents the dynamic interrogation of a wireless antenna sensor for mechanical vibration monitoring. In order to interrogate the antenna resonant frequency at sufficient high speeds, a wireless interrogator that consists of a Frequency Modulated Continuous Wave (FMCW) synthesizer, a signal demodulation unit, and a real-time digital signal processing program was developed. The principle of operation of the dynamic wireless sensing system is first described, followed by the description of the design and implementation of the antenna sensor and the wireless interrogator. After calibrate the antenna sensor response using static tensile tests, dynamic interrogation of the wireless antenna sensor was carried out by subjecting the test specimen to a sinusoidal tensile load. The resonant frequency shifts of the antenna sensor were compared with the strains calculated from the applied loads. A good agreement between the antenna sensor readings and the strain values were achieved. A sampling rate of up to 50 Hz was demonstrated.

  17. Research on characterization of wireless LANs traffic

    NASA Astrophysics Data System (ADS)

    Feng, Huifang; Shu, Yantai; Yang, Oliver W. W.

    2011-08-01

    In this paper, we employ actual wireless data that draw from well known archives of network traffic traces and investigate the characterization of the wireless LANs traffic. Firstly, useful preliminary information regarding the general wireless traffic dynamics is obtained using one standard statistical technique named Fourier power spectrum. Then the estimation of the parameters, such as the correlation dimension, the largest Lyapunov exponent and the principal components analysis indicate the existence of low-dimensional deterministic chaos in wireless traffic time series. Our results also show that the parameters selection of the phase space reconstruction influence the value of the correlation dimension and the largest Lyapunov exponent, but can not influence on diagnosis of chaotic nature of wireless traffic.

  18. Evaluation of wireless data communications at KSC

    NASA Technical Reports Server (NTRS)

    Gejji, Raghvendra R.

    1995-01-01

    This project is motivated by the need for temporary or emergency provisioning of LAN service at KSC. The main goal of the project was to evaluate existing wireless bridge equipment in the KSC environment. Wireless bridge equipment can be used to make a wireless connection between two remotely located LAN segments. This report describes the experimental setup used to evaluate the equipment, including antenna connections, workstation connections, bridge software and workstation software The rangefinder program on the bridge was used to gather data about how the RF propagation environment at KSC affects the performance of the wireless bridge. Data was gathered for indoor as well as outdoor propagation. The report concludes with recommendations on how to take into account the particular terrain and building structures at KSC to design future applications of wireless bridges.

  19. Deep optical access on multi-core and multi-mode fiber for integrated wireless applications

    NASA Astrophysics Data System (ADS)

    Llorente, Roberto; Morant, Maria; Beltrán, Marta; Macho, Andrés.

    2015-01-01

    Deep integrated optical access networks target to provide great capillarity and multiple ONTs for cost- and energy-efficient pervasive connectivity seamless supporting integrated wireless. Several key optical technologies are herein reported supporting integrated deep optical access: Bundled radio-over-fiber transmission is proposed and demonstrated for the provision of quintuple-play services achieving 125 km SSMF optical reach. Bend-insensitive fiber in-building distribution is also proposed and demonstrated supporting joint legacy coaxial transmission. Multimode POF is also proposed and demonstrated suitable for joint in-building distribution of MATV and SMATV broadcasting signals. Optical comb technology us is also demonstrated suitable for mm-wave radio generation of multiband OFDM wireless signals. Finally, multicore fiber transmission is also proposed and demonstrated suitable for the transmission of LTE and WIMAX in wireless fronthaul applications in a minimized inter-core crosstalk penalty configuration.

  20. Decay of superdeformed bands

    SciTech Connect

    Carpenter, M.P.; Khoo, T.L.; Lauritsen, T.

    1995-12-31

    One of the major challenges in the study of superdeformation is to directly connect the large number of superdeformed bands now known to the yrast states. In this way, excitation energies, spins and parities can be assigned to the levels in the second well which is essential to establish the collective and single-particle components of these bands. This paper will review some of the progress which has been made to understand the decay of superdeformed bands using the new arrays including the measurement of the total decay spectrum and the establishment of direct one-step decays from the superdeformed band to the yrast line in {sup 194}Hg. 42 refs., 5 figs.

  1. Wireless Energy Transfer Through Magnetic Reluctance Coupling

    NASA Astrophysics Data System (ADS)

    Pillatsch, P.

    2014-11-01

    Energy harvesting from human motion for body worn or implanted devices faces the problem of the wearer being still, e.g. while asleep. Especially for medical devices this can become an issue if a patient is bed-bound for prolonged periods of time and the internal battery of a harvesting system is not recharged. This article introduces a mechanism for wireless energy transfer based on a previously presented energy harvesting device. The internal rotor of the energy harvester is made of mild steel and can be actuated through a magnetic reluctance coupling to an external motor. The internal piezoelectric transducer is consequently actuated and generates electricity. This paper successfully demonstrates energy transfer over a distance of 16 mm in air and an achieved power output of 85 μW at 25 Hz. The device functional volume is 1.85 cm3. Furthermore, it was demonstrated that increasing the driving frequency beyond 25 Hz did not yield a further increase in power output. Future research will focus on improving the reluctance coupling, e.g. by investigating the use of multiple or stronger magnets, in order to increase transmission distance.

  2. Wireless Luminescence Integrated Sensors (WLIS)

    SciTech Connect

    Simpson, M.L.; Sayler, G.S.

    2003-11-10

    The goal of this project was the development of a family of wireless, single-chip, luminescence-sensing devices to solve a number of difficult distributed measurement problems in areas ranging from environmental monitoring and assessment to high-throughput screening of combinatorial chemistry libraries. These wireless luminescence integrated sensors (WLIS) consist of a microluminometer, wireless data transmitter, and RF power input circuit all realized in a standard integrated circuit (IC) process with genetically engineered, whole-cell, bioluminescent bioreporters encapsulated and deposited on the IC. The end product is a family of compact, low-power, rugged, low-cost sensors. As part of this program they developed an integrated photodiode/signal-processing scheme with an rms noise level of 175 electrons/second for a 13-minute integration time, and a quantum efficiency of 66% at the 490-nm bioluminescent wavelength. this performance provided a detection limit of < 1000 photons/second. Although sol-gel has previously been used to encapsulate yeast cells, the reaction conditions necessary for polymerization (primarily low pH) have beforehand proven too harsh for bacterial cell immobilizations. Utilizing sonication methods, they have were able to initiate polymerization under pH conditions conductive to cell survival. both a toluene bioreporter (Pseudomonas putida TVA8) and a naphthalene bioreporter (Pseudomonas fluorescens HK44) were successfully encapsulated in sol-gel and shown to produce a fairly significant bioluminescent response. In addition to the previously developed naphthalene- and toluene-sensitive bioreporters, they developed a yeast-based xenoestrogen reporter. This technology has been licensed by Micro Systems Technologies, a startup company in Dayton, Ohio for applications in environmental containments monitoring, and for detecting weapons of mass destruction (i.e. homeland security).

  3. 47 CFR 27.1305 - Shared wireless broadband network.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Shared wireless broadband network. 27.1305... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private Partnership § 27.1305 Shared wireless broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private...

  4. 78 FR 39345 - ACS Wireless, Inc.; Notice of Application

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-01

    ... COMMISSION ACS Wireless, Inc.; Notice of Application AGENCY: Securities and Exchange Commission (``Commission...''). Summary of Application: ACS Wireless, Inc. (``ACS Wireless'') seeks an order under section 3(b)(2) of the..., owning, holding or trading in securities. ACS Wireless is primarily engaged in providing...

  5. 47 CFR 27.1305 - Shared wireless broadband network.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Shared wireless broadband network. 27.1305... MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 700 MHz Public/Private Partnership § 27.1305 Shared wireless broadband network. The Shared Wireless Broadband Network developed by the 700 MHz Public/Private...

  6. World Without Wires: Is Your District Ready to Go Wireless?

    ERIC Educational Resources Information Center

    Villano, Matt

    2005-01-01

    In this article, the author presents the latest wireless equipments available in market. For starters, wireless networks offer mobility and flexibility: users of laptops, PDAs, tablet PCs, and wireless Voice over IP telephones can move freely about campus while staying connected to the Internet. There are two kinds of wireless networks: ad-hoc, or…

  7. Capacity Limit, Link Scheduling and Power Control in Wireless Networks

    ERIC Educational Resources Information Center

    Zhou, Shan

    2013-01-01

    The rapid advancement of wireless technology has instigated the broad deployment of wireless networks. Different types of networks have been developed, including wireless sensor networks, mobile ad hoc networks, wireless local area networks, and cellular networks. These networks have different structures and applications, and require different…

  8. Laparoscopic Gastric Banding

    PubMed Central

    Suter, Michel; Giusti, Vittorio; Worreth, Marc; Héraief, Eric; Calmes, Jean-Marie

    2005-01-01

    Objective: The objective of this study was to evaluate the results of laparoscopic gastric banding using 2 different bands (the Lapband [Bioenterics, Carpinteria, CA] and the SAGB [Swedish Adjustable Gastric Band; Obtech Medical, 6310 Zug, Switzerland]) in terms of weight loss and correction of comorbidities, short-and long-term complications, and improvement of quality of life in morbidly obese patients Summary Background Data: During the past 10 years, gastric banding has become 1 of the most common bariatric procedures, at least in Europe and Australia. Weight loss can be excellent, but it is not sufficient in a significant proportion of patients, and a number of long-term complications can develop. We hypothesized that the type of band could be of importance in the outcome. Methods: One hundred eighty morbidly obese patients were randomly assigned to receive the Lapband or the SAGB. All the procedures were performed by the same surgeon. The primary end point was weight loss, and secondary end points were correction of comorbidities, early- and long-term complications, importance of food restriction, and improvement of quality of life. Results: Initial weight loss was faster in the Lapband group, but weight loss was eventually identical in the 2 groups. There was a trend toward more early band-related complications and more band infections with the SAGB, but the study had limited power in that respect. Correction of comorbidities, food restriction, long-term complications, and improvement of quality of life were identical. Only 55% to 60% of the patients achieved an excess weight loss of at least 50% in both groups. There was no difference in the incidence of long-term complications. Conclusions: Gastric banding can be performed safely with the Lapband or the SAGB with similar short- and midterm results with respect to weight loss and morbidity. Only 50% to 60% of the patients will achieve sufficient weight loss, and close to 10% at least will develop severe

  9. Development of a Novel Wireless Electric Power Transfer System for Space Applications

    NASA Technical Reports Server (NTRS)

    VazquezRamos, Gabriel; Yuan, Jiann-Shiun

    2011-01-01

    This paper will introduce a new implementation for wireless electric power transfer systems: space applications. Due to the risks that constitute the use of electrical connector for some space missions/applications, a simple wireless power system design approach will be evaluated as an alternative for the use of electrical connectors. This approach takes into consideration the overall system performance by designing the magnetic resonance elements and by verifying the overall system electrical behavior. System characterization is accomplished by executing circuit and analytical simulations using Matlab(TradeMark) and LTSpiceIV(TradeMark) software packages. The design methodology was validated by two different experiments: frequency consideration (design of three magnetic elements) and a small scale proof-ofconcept prototype. Experiment results shows successful wireless power transfer for all the cases studied. The proof-of-concept prototype provided approx.4 W of wireless power to the load (light bulb) at a separation of 3 cm from the source. In addition. a resonant circuit was designed and installed to the battery terminals of a handheld radio without batteries, making it tum on at a separation of approx.5 cm or less from the source. It was also demonstrated by prototype experimentation that multiple loads can be powered wirelessly at the same time with a single electric power source.

  10. Fly-by-Wireless Update

    NASA Technical Reports Server (NTRS)

    Studor, George

    2010-01-01

    The presentation reviews what is meant by the term 'fly-by-wireless', common problems and motivation, provides recent examples, and examines NASA's future and basis for collaboration. The vision is to minimize cables and connectors and increase functionality across the aerospace industry by providing reliable, lower cost, modular, and higher performance alternatives to wired data connectivity to benefit the entire vehicle/program life-cycle. Focus areas are system engineering and integration methods to reduce cables and connectors, vehicle provisions for modularity and accessibility, and a 'tool box' of alternatives to wired connectivity.

  11. Wireless power transfer magnetic couplers

    DOEpatents

    Wu, Hunter; Gilchrist, Aaron; Sealy, Kylee

    2016-01-19

    A magnetic coupler is disclosed for wireless power transfer systems. A ferrimagnetic component is capable of guiding a magnetic field. A wire coil is wrapped around at least a portion of the ferrimagnetic component. A screen is capable of blocking leakage magnetic fields. The screen may be positioned to cover at least one side of the ferrimagnetic component and the coil. A distance across the screen may be at least six times an air gap distance between the ferrimagnetic component and a receiving magnetic coupler.

  12. WMSA for wireless communication applications

    NASA Astrophysics Data System (ADS)

    Vats, Monika; Agarwal, Alok; Kumar, Ravindra

    2016-03-01

    Modified rectangular compact microstrip patch antenna having finite ground plane is proposed in this paper. Wideband Microstrip Antenna (WMSA) is achieved by corner cut and inserting air gaps inside the edges of the radiating patch having finite ground plane. The obtained impedance bandwidth for 10 dB return loss for the operating frequency f0 = 2.09 GHz is 28.7 % (600 MHz), which is very high as compared to the bandwidth obtained for the conventional microstrip antenna. Compactness with wide bandwidth of this antenna is practically useful for the wireless communication systems.

  13. Data-Driven Design of Intelligent Wireless Networks: An Overview and Tutorial.

    PubMed

    Kulin, Merima; Fortuna, Carolina; De Poorter, Eli; Deschrijver, Dirk; Moerman, Ingrid

    2016-06-01

    Data science or "data-driven research" is a research approach that uses real-life data to gain insight about the behavior of systems. It enables the analysis of small, simple as well as large and more complex systems in order to assess whether they function according to the intended design and as seen in simulation. Data science approaches have been successfully applied to analyze networked interactions in several research areas such as large-scale social networks, advanced business and healthcare processes. Wireless networks can exhibit unpredictable interactions between algorithms from multiple protocol layers, interactions between multiple devices, and hardware specific influences. These interactions can lead to a difference between real-world functioning and design time functioning. Data science methods can help to detect the actual behavior and possibly help to correct it. Data science is increasingly used in wireless research. To support data-driven research in wireless networks, this paper illustrates the step-by-step methodology that has to be applied to extract knowledge from raw data traces. To this end, the paper (i) clarifies when, why and how to use data science in wireless network research; (ii) provides a generic framework for applying data science in wireless networks; (iii) gives an overview of existing research papers that utilized data science approaches in wireless networks; (iv) illustrates the overall knowledge discovery process through an extensive example in which device types are identified based on their traffic patterns; (v) provides the reader the necessary datasets and scripts to go through the tutorial steps themselves.

  14. Data-Driven Design of Intelligent Wireless Networks: An Overview and Tutorial.

    PubMed

    Kulin, Merima; Fortuna, Carolina; De Poorter, Eli; Deschrijver, Dirk; Moerman, Ingrid

    2016-01-01

    Data science or "data-driven research" is a research approach that uses real-life data to gain insight about the behavior of systems. It enables the analysis of small, simple as well as large and more complex systems in order to assess whether they function according to the intended design and as seen in simulation. Data science approaches have been successfully applied to analyze networked interactions in several research areas such as large-scale social networks, advanced business and healthcare processes. Wireless networks can exhibit unpredictable interactions between algorithms from multiple protocol layers, interactions between multiple devices, and hardware specific influences. These interactions can lead to a difference between real-world functioning and design time functioning. Data science methods can help to detect the actual behavior and possibly help to correct it. Data science is increasingly used in wireless research. To support data-driven research in wireless networks, this paper illustrates the step-by-step methodology that has to be applied to extract knowledge from raw data traces. To this end, the paper (i) clarifies when, why and how to use data science in wireless network research; (ii) provides a generic framework for applying data science in wireless networks; (iii) gives an overview of existing research papers that utilized data science approaches in wireless networks; (iv) illustrates the overall knowledge discovery process through an extensive example in which device types are identified based on their traffic patterns; (v) provides the reader the necessary datasets and scripts to go through the tutorial steps themselves. PMID:27258286

  15. Data-Driven Design of Intelligent Wireless Networks: An Overview and Tutorial

    PubMed Central

    Kulin, Merima; Fortuna, Carolina; De Poorter, Eli; Deschrijver, Dirk; Moerman, Ingrid

    2016-01-01

    Data science or “data-driven research” is a research approach that uses real-life data to gain insight about the behavior of systems. It enables the analysis of small, simple as well as large and more complex systems in order to assess whether they function according to the intended design and as seen in simulation. Data science approaches have been successfully applied to analyze networked interactions in several research areas such as large-scale social networks, advanced business and healthcare processes. Wireless networks can exhibit unpredictable interactions between algorithms from multiple protocol layers, interactions between multiple devices, and hardware specific influences. These interactions can lead to a difference between real-world functioning and design time functioning. Data science methods can help to detect the actual behavior and possibly help to correct it. Data science is increasingly used in wireless research. To support data-driven research in wireless networks, this paper illustrates the step-by-step methodology that has to be applied to extract knowledge from raw data traces. To this end, the paper (i) clarifies when, why and how to use data science in wireless network research; (ii) provides a generic framework for applying data science in wireless networks; (iii) gives an overview of existing research papers that utilized data science approaches in wireless networks; (iv) illustrates the overall knowledge discovery process through an extensive example in which device types are identified based on their traffic patterns; (v) provides the reader the necessary datasets and scripts to go through the tutorial steps themselves. PMID:27258286

  16. Polygonal deformation bands

    NASA Astrophysics Data System (ADS)

    Antonellini, Marco; Mollema, Pauline Nella

    2015-12-01

    We report for the first time the occurrence of polygonal faults in sandstone, which is compelling given that layer-bound polygonal fault systems have been observed so far only in fine-grained sediments such as clay and chalk. The polygonal faults are shear deformation bands that developed under shallow burial conditions via strain hardening in dm-wide zones. The edges of the polygons are 1-5 m long. The shear deformation bands are organized as conjugate faults along each edge of the polygon and form characteristic horst-like structures. The individual deformation bands have slip magnitudes ranging from a few mm to 1.5 cm; the cumulative average slip magnitude in a zone is up to 10 cm. The deformation bands heaves, in aggregate form, accommodate a small isotropic horizontal extension (strain <0.005). The individual shear deformation bands show abutting T-junctions, veering, curving, and merging where they mechanically interact. Crosscutting relationships are rare. The interactions of the deformation bands are similar to those of mode I opening fractures. The documented fault networks have important implications for evaluating the geometry of km-scale polygonal fault systems in the subsurface, top seal integrity, as well as constraining paleo-tectonic stress regimes.

  17. Polygonal deformation bands

    NASA Astrophysics Data System (ADS)

    Antonellini, Marco; Mollema, Pauline Nella

    2015-12-01

    We report for the first time the occurrence of polygonal faults in sandstone, which is compelling given that layer-bound polygonal fault systems have been observed so far only in fine-grained sediments such as clay and chalk. The polygonal faults are shear deformation bands that developed under shallow burial conditions via strain hardening in dm-wide zones. The edges of the polygons are 1-5 m long. The shear deformation bands are organized as conjugate faults along each edge of the polygon and form characteristic horst-like structures. The individual deformation bands have slip magnitudes ranging from a few mm to 1.5 cm; the cumulative average slip magnitude in a zone is up to 10 cm. The deformation bands heaves, in aggregate form, accommodate a small isotropic horizontal extension (strain <0.005). The individual shear deformation bands show abutting T-junctions, veering, curving, and merging where they mechanically interact. Crosscutting relationships are rare. The interactions of the deformation bands are similar to those of mode I opening fractures. The documented fault networks have important implications for evaluating the geometry of km-scale polygonal fault systems in the subsurface, top seal integrity, as well as constraining paleo-tectonic stress regimes.

  18. A prenatally ascertained, maternally inherited 14.8 Mb duplication of chromosomal bands Xq13.2-q21.31 associated with multiple congenital abnormalities in a male fetus.

    PubMed

    Sismani, C; Donoghue, J; Alexandrou, A; Karkaletsi, M; Christopoulou, S; Konstantinidou, A E; Livanos, P; Patsalis, P C; Velissariou, V

    2013-11-01

    Duplications of the X chromosome are rare cytogenetic findings, and have been associated with an abnormal phenotype in the male offspring of apparently normal or near normal female carriers. We report on the prenatal diagnosis of a duplication on the long arm of chromosome X from chromosomal band Xq13.2 to q21.31 in a male fetus with increased nuchal translucency in the first trimester and polyhydramnios at 22 weeks of gestation. Amniocentesis was undertaken and cytogenetic analysis revealed additional chromosomal material in the long arm of chromosome X at position Xq13. Analysis with high resolution array CGH revealed the additional material is in fact a duplication of the region Xq13.2-q21.13. The duplication is 14.8 Mb in size and includes fourteen genes: SLC16A2, KIAA2022, ABCB7, ZDHHC15, ATRX, MAGT1, ATP7A, PGK1, TBX22, BRWD3, POU3F4, ZNF711, POF1B and CHM. Analysis of the parents revealed the mother to be a carrier of the same duplication. After elected termination of the pregnancy at 28 weeks a detailed autopsy of the fetus allowed for genotype-phenotype correlations.

  19. Health Risks Faced by Public School Band Directors

    ERIC Educational Resources Information Center

    Woolery, Danielle N.; Woolery, Jesse A.

    2013-01-01

    Public school band directors face many work-related hazards in their grueling, yet rewarding job. As a school year progresses, directors are expected to work long hours, while trying to balance professional and personal responsibilities. A band director whose career spans multiple decades can potentially face a number of serious medical problems.…

  20. Optical wireless applications: a solution to ease the wireless airwaves spectrum crunch

    NASA Astrophysics Data System (ADS)

    Kavehrad, M.

    2013-01-01

    Demands by the communications industry for greater and greater bandwidth push the capability of conventional wireless technology. Part of the Radio Spectrum that is suitable for mobility is very limited. Higher frequency waves above 30 GHz tend to travel only a few miles or less and generally do not penetrate solid materials very well. This offers a sustainable solution for the current Spectrum Crunch in the lower microwave bands. One mission of this paper is to demonstrate practical and usable networks that can select a self-limiting link distance, allowing spectrum reuse. The motivation for operators of such bands to actually choose to self-limit is that by doing so, they improve the signal-tonoise against competing users at a lower cost than trying to overcome interference. These characteristics of wave propagation are not necessarily disadvantageous as they enable more densely packed communications links. Thus, high frequencies can provide very efficient spectrum utilization through "selective spectrum reuse", and naturally increase the security of transmissions. Optical systems and networks offer a far greater bandwidth. This means new devices and systems have to be developed. Semiconductor Light Emitting Diode (LED) is considered to be the future primary lighting source for buildings, automobiles and aircrafts. LED provides higher energy efficiency compared to incandescent and fluorescent light sources and it will play a major role in the global reduction of carbon dioxide emissions, as a consequence of the significant energy savings. Lasers are also under investigation for similar applications. These core devices have the potential to revolutionize how we use light, including not only for illumination, but as well; for communications, sensing, navigation, positioning, surveillance, and imaging.

  1. Energy efficiency and reliability in wireless biomedical implant systems.

    PubMed

    Abouei, Jamshid; Brown, J David; Plataniotis, Konstantinos N Kostas; Pasupathy, Subbarayan

    2011-05-01

    The use of wireless implant technology requires correct delivery of the vital physiological signs of the patient along with the energy management in power-constrained devices. Toward these goals, we present an augmentation protocol for the physical layer of the medical implant communications service (MICS) with focus on the energy efficiency of deployed devices over the MICS frequency band. The present protocol uses the rateless code with the frequency-shift keying (FSK) modulation scheme to overcome the reliability and power cost concerns in tiny implantable sensors due to the considerable attenuation of propagated signals across the human body. In addition, the protocol allows a fast start-up time for the transceiver circuitry. The main advantage of using rateless codes is to provide an inherent adaptive duty cycling for power management, due to the flexibility of the rateless code rate. Analytical results demonstrate that an 80% energy saving is achievable with the proposed protocol when compared to the IEEE 802.15.4 physical layer standard with the same structure used for wireless sensor networks. Numerical results show that the optimized rateless coded FSK is more energy efficient than that of the uncoded FSK scheme for deep tissue (e.g., digestive endoscopy) applications, where the optimization is performed over modulation and coding parameters. PMID:21233054

  2. A Compression Algorithm in Wireless Sensor Networks of Bearing Monitoring

    NASA Astrophysics Data System (ADS)

    Bin, Zheng; Qingfeng, Meng; Nan, Wang; Zhi, Li

    2011-07-01

    The energy consumption of wireless sensor networks (WSNs) is always an important problem in the application of wireless sensor networks. This paper proposes a data compression algorithm to reduce amount of data and energy consumption during the data transmission process in the on-line WSNs-based bearing monitoring system. The proposed compression algorithm is based on lifting wavelets, Zerotree coding and Hoffman coding. Among of that, 5/3 lifting wavelets is used for dividing data into different frequency bands to extract signal characteristics. Zerotree coding is applied to calculate the dynamic thresholds to retain the attribute data. The attribute data are then encoded by Hoffman coding to further enhance the compression ratio. In order to validate the algorithm, simulation is carried out by using Matlab. The result of simulation shows that the proposed algorithm is very suitable for the compression of bearing monitoring data. The algorithm has been successfully used in online WSNs-based bearing monitoring system, in which TI DSP TMS320F2812 is used to realize the algorithm.

  3. Partnership Opportunities with AFRC for Wireless Systems Flight Testing

    NASA Technical Reports Server (NTRS)

    Hang, Richard

    2015-01-01

    The presentation will overview the flight test capabilities at NASA Armstrong Flight Research Center (AFRC), to open up partnership collaboration opportunities for Wireless Community to conduct flight testing of aerospace wireless technologies. Also, it will brief the current activities on wireless sensor system at AFRC through SBIR (Small Business Innovation Research) proposals, and it will show the current areas of interest on wireless technologies that AFRC would like collaborate with Wireless Community to further and testing.

  4. Tethys’ Mysterious Equatorial Band

    NASA Astrophysics Data System (ADS)

    Elder, Catherine; Helfenstein, P.; Thomas, P.; Veverka, J.; Burns, J. A.; Denk, T.; Porco, C.

    2007-10-01

    We investigate a conspicuous equatorial albedo band on Tethys by analyzing Cassini Imaging Science Subsystem (ISS) Narrow Angle Camera (NAC) images obtained in several wavelengths. The band, first seen in Voyager data by Stooke (1989;2002) is symmetric 15° on either side of the equator and extends from 0° to 160°W that is, almost centered on the leading part of Tethys. There is no evidence that the band is topographically-based; margins are gradational and there is no visible difference in underlying geology. Because of the otherwise broadly-uniform albedo of Tethys, subtle albedo and color variations are easily detected and we sampled them after correcting each image for wavelength-dependent limb darkening effects using Hapke's (2002) photometric model. In the ISS CL1-CL2 filter (611nm), the average albedo contrast of the band with adjacent cratered plains is only about 3%. Compared to its surroundings, the band is about 2-3% brighter in the NAC CL1-UV3 filter (338nm), 2-3% darker in the NAC CL1-GRN (568nm) and 8% darker in the NAC CL1-IR3 filter (930nm). This may indicate that the band exposes regolith composed of cleaner ice with a different grain-size distribution than surrounding materials. The average global photometric properties of Tethys are affected by the E-Ring (Verbiscer et al. 2007). However, dynamical explanations for the narrow albedo band that involve E-ring particles so far are unlikely given the broad nature of the E-ring and the inclination of Tethys. References: Hapke, B. 2002. Icarus 157, 523-534; Stooke, P.J. 1989. Lunar and Planet. Sci. Conf. 20th, 1071-1072; Stooke, P.J. 2002, Lunar and Planet. Sci. Conf, 33rd, #1553; Verbiscer et al. 2007. Science 315, pp.815.

  5. Distributed wireless quantum communication networks

    NASA Astrophysics Data System (ADS)

    Yu, Xu-Tao; Xu, Jin; Zhang, Zai-Chen

    2013-09-01

    The distributed wireless quantum communication network (DWQCN) has a distributed network topology and transmits information by quantum states. In this paper, we present the concept of the DWQCN and propose a system scheme to transfer quantum states in the DWQCN. The system scheme for transmitting information between any two nodes in the DWQCN includes a routing protocol and a scheme for transferring quantum states. The routing protocol is on-demand and the routing metric is selected based on the number of entangled particle pairs. After setting up a route, quantum teleportation and entanglement swapping are used for transferring quantum states. Entanglement swapping is achieved along with the process of routing set up and the acknowledgment packet transmission. The measurement results of each entanglement swapping are piggybacked with route reply packets or acknowledgment packets. After entanglement swapping, a direct quantum link between source and destination is set up and quantum states are transferred by quantum teleportation. Adopting this scheme, the measurement results of entanglement swapping do not need to be transmitted specially, which decreases the wireless transmission cost and transmission delay.

  6. Wireless Microstimulators for Neural Prosthetics

    PubMed Central

    Sahin, Mesut; Pikov, Victor

    2016-01-01

    One of the roadblocks in the field of neural prosthetics is the lack of microelectronic devices for neural stimulation that can last a lifetime in the central nervous system. Wireless multi-electrode arrays are being developed to improve the longevity of implants by eliminating the wire interconnects as well as the chronic tissue reactions due to the tethering forces generated by these wires. An area of research that has not been sufficiently investigated is a simple single-channel passive microstimulator that can collect the stimulus energy that is transmitted wirelessly through the tissue and immediately convert it into the stimulus pulse. For example, many neural prosthetic approaches to intraspinal microstimulation require only a few channels of stimulation. Wired spinal cord implants are not practical for human subjects because of the extensive flexions and rotations that the spinal cord experiences. Thus, intraspinal microstimulation may be a pioneering application that can benefit from submillimetersize floating stimulators. Possible means of energizing such a floating microstimulator, such as optical, acoustic, and electromagnetic waves, are discussed. PMID:21488815

  7. Wireless Augmented Reality Prototype (WARP)

    NASA Technical Reports Server (NTRS)

    Devereaux, A. S.

    1999-01-01

    Initiated in January, 1997, under NASA's Office of Life and Microgravity Sciences and Applications, the Wireless Augmented Reality Prototype (WARP) is a means to leverage recent advances in communications, displays, imaging sensors, biosensors, voice recognition and microelectronics to develop a hands-free, tetherless system capable of real-time personal display and control of computer system resources. Using WARP, an astronaut may efficiently operate and monitor any computer-controllable activity inside or outside the vehicle or station. The WARP concept is a lightweight, unobtrusive heads-up display with a wireless wearable control unit. Connectivity to the external system is achieved through a high-rate radio link from the WARP personal unit to a base station unit installed into any system PC. The radio link has been specially engineered to operate within the high- interference, high-multipath environment of a space shuttle or space station module. Through this virtual terminal, the astronaut will be able to view and manipulate imagery, text or video, using voice commands to control the terminal operations. WARP's hands-free access to computer-based instruction texts, diagrams and checklists replaces juggling manuals and clipboards, and tetherless computer system access allows free motion throughout a cabin while monitoring and operating equipment.

  8. Wireless microstimulators for neural prosthetics.

    PubMed

    Sahin, Mesut; Pikov, Victor

    2011-01-01

    One of the roadblocks in the field of neural prosthetics is the lack of microelectronic devices for neural stimulation that can last a lifetime in the central nervous system. Wireless multi-electrode arrays are being developed to improve the longevity of implants by eliminating the wire interconnects as well as the chronic tissue reactions due to the tethering forces generated by these wires. An area of research that has not been sufficiently investigated is a simple single-channel passive microstimulator that can collect the stimulus energy that is transmitted wirelessly through the tissue and immediately convert it into the stimulus pulse. For example, many neural prosthetic approaches to intraspinal microstimulation require only a few channels of stimulation. Wired spinal cord implants are not practical for human subjects because of the extensive flexions and rotations that the spinal cord experiences. Thus, intraspinal microstimulation may be a pioneering application that can benefit from submillimeter-size floating stimulators. Possible means of energizing such a floating microstimulator, such as optical, acoustic, and electromagnetic waves, are discussed. PMID:21488815

  9. Amniotic Band Syndrome - A Dreaded Condition

    PubMed Central

    Renukadevi, T.K.

    2016-01-01

    Amniotic band syndrome is a unique condition in which amnion a normal structure causes complications. A case of second gravid, obese who is a known diabetic came to OPD at 13 weeks pregnancy for regular antenatal check up. A routine ultrasonogram was advised in which multiple anomalies were noted and the diagnosis of amniotic band syndrome was made. The parents were counseled for medical termination of pregnancy and after obtaining the consent termination were performed and the parents were asked to postpone the next pregnancy for minimum 6 months. This anomaly as seen in this patient could be due to risk factors like diabetes and obesity. PMID:26894130

  10. Amniotic Band Syndrome - A Dreaded Condition.

    PubMed

    R, Durga; Renukadevi, T K

    2016-01-01

    Amniotic band syndrome is a unique condition in which amnion a normal structure causes complications. A case of second gravid, obese who is a known diabetic came to OPD at 13 weeks pregnancy for regular antenatal check up. A routine ultrasonogram was advised in which multiple anomalies were noted and the diagnosis of amniotic band syndrome was made. The parents were counseled for medical termination of pregnancy and after obtaining the consent termination were performed and the parents were asked to postpone the next pregnancy for minimum 6 months. This anomaly as seen in this patient could be due to risk factors like diabetes and obesity.

  11. Evaluation of wireless Local Area Networks

    NASA Astrophysics Data System (ADS)

    McBee, Charles L.

    1993-09-01

    This thesis is an in-depth evaluation of the current wireless Local Area Network (LAN) technologies. Wireless LAN's consist of three technologies: they are infrared light, microwave, and spread spectrum. When the first wireless LAN's were introduced, they were unfavorably labeled slow, expensive, and unreliable. The wireless LAN's of today are competitively priced, more secure, easier to install, and provide equal to or greater than the data throughput of unshielded twisted pair cable. Wireless LAN's are best suited for organizations that move office staff frequently, buildings that have historical significance, or buildings that have asbestos. Additionally, an organization may realize a cost savings of between $300 to $1,200 each time a node is moved. Current wireless LAN technologies have a positive effect on LAN standards being developed by the Defense Information System Agency (DISA). DoD as a whole is beginning to focus on wireless LAN's and mobile communications. If system managers want to remain successful, they need to stay abreast of this technology.

  12. Wireless Temperature-Monitoring System

    NASA Technical Reports Server (NTRS)

    Solano, Wanda; Thurman, Chuck

    2002-01-01

    A relatively inexpensive instrumentation system that includes units that are connected to thermocouples and that are parts of a radio-communication network has been developed to enable monitoring of temperatures at multiple locations. Because there is no need to string wires or cables for communication, the system is well suited for monitoring temperatures at remote locations and for applications in which frequent changes of monitored or monitoring locations are needed. The system can also be adapted to monitoring of slowly varying physical quantities, other than temperature, that can be transduced by solid-state electronic sensors. electronic sensors. The system comprises any number of transmitting units and a single receiving unit. Each transmitting unit includes connections for as many as four external thermocouples, a signal-conditioning module, a control module, and a radio-communication module. The signal-conditioning module acts as an interface between the thermocouples and the rest of the transmitting unit and includes a built-in solid ambient temperature sensor that is in addition to the external thermocouples. The control module is a system-on-chip embedded processor that includes analog-to-digital converters, serial and parallel data ports, and an interface for local connection to an analog meter that is used during installation to verify correct operation. The radio-communication module contains a commercial spread-spectrum transceiver that operates in the 900-MHz industrial, scientific, and medical (ISM) frequency band. This transceiver transmits data to the receiving unit at a rate of 19,200 baud. The receiving unit includes a transceiver like that of a transmitting unit, plus a control module that contains a system-on-chip processor that includes serial data port for output to a computer that runs monitoring and/or control software, a parallel data port for output to a printer, and a seven-segment light-emitting-diode display. Each transmitting unit

  13. Adaptive Modulation and Coding for LTE Wireless Communication

    NASA Astrophysics Data System (ADS)

    Hadi, S. S.; Tiong, T. C.

    2015-04-01

    Long Term Evolution (LTE) is the new upgrade path for carrier with both GSM/UMTS networks and CDMA2000 networks. The LTE is targeting to become the first global mobile phone standard regardless of the different LTE frequencies and bands use in other countries barrier. Adaptive Modulation and Coding (AMC) is used to increase the network capacity or downlink data rates. Various modulation types are discussed such as Quadrature Phase Shift Keying (QPSK), Quadrature Amplitude Modulation (QAM). Spatial multiplexing techniques for 4×4 MIMO antenna configuration is studied. With channel station information feedback from the mobile receiver to the base station transmitter, adaptive modulation and coding can be applied to adapt to the mobile wireless channels condition to increase spectral efficiencies without increasing bit error rate in noisy channels. In High-Speed Downlink Packet Access (HSDPA) in Universal Mobile Telecommunications System (UMTS), AMC can be used to choose modulation types and forward error correction (FEC) coding rate.

  14. RFID Tag Helix Antenna Sensors for Wireless Drug Dosage Monitoring.

    PubMed

    Huang, Haiyu; Zhao, Peisen; Chen, Pai-Yen; Ren, Yong; Liu, Xuewu; Ferrari, Mauro; Hu, Ye; Akinwande, Deji

    2014-01-01

    Miniaturized helix antennas are integrated with drug reservoirs to function as RFID wireless tag sensors for real-time drug dosage monitoring. The general design procedure of this type of biomedical antenna sensors is proposed based on electromagnetic theory and finite element simulation. A cost effective fabrication process is utilized to encapsulate the antenna sensor within a biocompatible package layer using PDMS material, and at the same time form a drug storage or drug delivery unit inside the sensor. The in vitro experiment on two prototypes of antenna sensor-drug reservoir assembly have shown the ability to monitor the drug dosage by tracking antenna resonant frequency shift from 2.4-2.5-GHz ISM band with realized sensitivity of 1.27 [Formula: see text] for transdermal drug delivery monitoring and 2.76-[Formula: see text] sensitivity for implanted drug delivery monitoring. PMID:27170865

  15. Resonant ultrasonic wireless power transmission for bio-implants

    NASA Astrophysics Data System (ADS)

    Lee, Sung Q.; Youm, Woosub; Hwang, Gunn; Moon, Kee S.; Ozturk, Yusuf

    2014-03-01

    In this paper, we present the ultrasonic wireless power transmission system as part of a brain-machine interface (BMI) system in development to supply the required electric power. Making a small-size implantable BMI, it is essential to design a low power unit with a rechargeable battery. The ultrasonic power transmission system has two piezoelectric transducers, facing each other between skin tissues converting electrical energy to mechanical vibrational energy or vice versa. Ultrasound is free from the electromagnetic coupling effect and medical frequency band limitations which making it a promising candidate for implantable purposes. In this paper, we present the design of piezoelectric composite transducer, the rectifier circuit, and rechargeable battery that all packaged in biocompatible titanium can. An initial prototype device was built for demonstration purpose. The early experimental results demonstrate the prototype device can reach 50% of energy transmission efficiency in a water medium at 20mm distance and 18% in animal skin tissue at 18mm distance, respectively.

  16. Photonic band gap materials

    NASA Astrophysics Data System (ADS)

    Cassagne, D.

    Photonic band gap materials Photonic band gap materials are periodic dielectric structures that control the propagation of electromagnetic waves. We describe the plane wave method, which allows to calculate the band structures of photonic crystals. By symmetry analysis and a perturbative approach, we predict the appearance of the low energy photonic band gaps of hexagonal structures. We propose new two-dimensional structures called graphite and boron nitride. Using a transfer matrix method, we calculate the transmission of the graphite structure and we show the crucial role of the coupling with external modes. We study the appearance of allowed modes in the photonic band gap by the introduction of localized defects in the periodicity. Finally, we discuss the properties of opals formed by self-organized silica microspheres, which are very promising for the fabrication of three-dimensional photonic crystals. Les matériaux à bandes interdites photoniques sont des structures diélectriques périodiques qui contrôlent la propagation des ondes électromagnétiques. Nous décrivons la méthode des ondes planes qui permet de calculer les structures de bandes des cristaux photoniques. Par une analyse de la symétrie et une approche perturbative, nous précisons les conditions d'existence des bandes interdites de basse énergie. Nous proposons de nouvelles structures bidimensionnelles appelées graphite et nitrure de bore. Grâce à une méthode de matrices de transfert, nous calculons la transmission de la structure graphite et nous mettons en évidence le rôle fondamental du couplage avec les modes extérieurs. Nous étudions l'apparition de modes permis dans la bande interdite grâce à l'introduction de défauts dans la périodicité. Enfin, nous discutons les propriétés des opales constituées de micro-billes de silice auto-organisées, qui sont très prometteuses pour la fabrication de cristaux photoniques tridimensionnels.

  17. 47 CFR 27.17 - Discontinuance of service in the 2000-2020 MHz and 2180-2200 MHz bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Discontinuance of service in the 2000-2020 MHz and 2180-2200 MHz bands. 27.17 Section 27.17 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES Applications and...

  18. 47 CFR 27.1102 - Designated Entities in the 1710-1755 MHz and 2110-2155 MHz bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Designated Entities in the 1710-1755 MHz and 2110-2155 MHz bands. 27.1102 Section 27.1102 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz,...

  19. 47 CFR 27.1132 - Protection of incumbent operations in the 2150-2160/62 MHz band.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Protection of incumbent operations in the 2150-2160/62 MHz band. 27.1132 Section 27.1132 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1710-1755 MHz,...

  20. 47 CFR 27.1002 - Designated entities in the 1915-1920 MHz and 1995-2000 MHz bands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Designated entities in the 1915-1920 MHz and 1995-2000 MHz bands. 27.1002 Section 27.1002 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) COMMON CARRIER SERVICES MISCELLANEOUS WIRELESS COMMUNICATIONS SERVICES 1915-1920 MHz and...