Science.gov

Sample records for rate-adaptive wireless communication

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Airborne wireless communication systems, airborne communication methods, and communication methods

    DOEpatents

    Deaton, Juan D.; Schmitt, Michael J.; Jones, Warren F.

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. [Wireless human body communication technology].

    PubMed

    Sun, Lei; Zhang, Xiaojuan

    2014-12-01

    The Wireless Body Area Network (WBAN) is a key part of the wearable monitoring technologies, which has many communication technologies to choose from, like Bluetooth, ZigBee, Ultra Wideband, and Wireless Human Body Communication (WHBC). As for the WHBC developed in recent years, it is worthy to be further studied. The WHBC has a strong momentum of growth and a natural advantage in the formation of WBAN. In this paper, we first briefly describe the technical background of WHBC, then introduce theoretical model of human-channel communication and digital transmission machine based on human channel. And finally we analyze various of the interference of the WHBC and show the AFH (Adaptive Frequency Hopping) technology which can effectively deal with the interference. PMID:25868265

  15. Wireless Communications in Space

    NASA Technical Reports Server (NTRS)

    2004-01-01

    In 1992, NASA and the U.S. Department of Defense jointly commissioned the research and development of a technology solution to address the challenges and requirements of communicating with their spacecraft. The project yielded an international consortium composed of representatives from the space science community, industry, and academia. This group of experts developed a broad suite of protocols specifically designed for space-based communications, known today as Space Communications Protocol Standards (SCPS). Having been internationally standardized by the Consultative Committee on Space Data Systems and the International Standards Organization, SCPS is distributed as open source technology by NASA s Jet Propulsion Laboratory (JPL). The protocols are used for every national space mission that takes place today.

  16. 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.

  17. 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.

  18. 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.

  19. 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…

  20. 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.

  1. Robust rate-adaptive hybrid ARQ scheme for frequency-hopped spread-spectrum multiple-access communication systems

    NASA Astrophysics Data System (ADS)

    Bigloo, Amir M. Y.; Gulliver, T. Aaron; Wang, Q.; Bhargava, Vijay K.

    1994-06-01

    This paper considers the application of rate-adaptive coding (RAC) to a spread spectrum multiple access (SSMA) communication system. Specifically, RAC using a variable rate Reed-Solomon (RS) code with a single decoder is applied to frequency-hopped SSMA. We show that this combination can accommodate a larger number of users compared to that with conventional fixed-rate coding. This increase is a result of a reduction in the channel interference from other users. The penalty for this improvement in most cases is a slight increase in the delay (composed of propagation and decoding delay). The throughput and the undetected error probability for a Q-ary symmetric channel are analyzed, and performance results are presented.

  2. Tags, wireless communication systems, tag communication methods, and wireless communications methods

    DOEpatents

    Scott; Jeff W. , Pratt; Richard M.

    2006-09-12

    Tags, wireless communication systems, tag communication methods, and wireless communications methods are described. In one aspect, a tag includes a plurality of antennas configured to receive a plurality of first wireless communication signals comprising data from a reader, a plurality of rectifying circuits coupled with. respective individual ones of the antennas and configured to provide rectified signals corresponding to the first wireless communication signals, wherein the rectified signals are combined to produce a composite signal, an adaptive reference circuit configured to vary a reference signal responsive to the composite signal, a comparator coupled with the adaptive reference circuit and the rectifying circuits and configured to compare the composite signal with respect to the reference signal and to output the data responsive to the comparison, and processing circuitry configured to receive the data from the comparator and to process the data.

  3. MC-CDMA for optical wireless communications

    NASA Astrophysics Data System (ADS)

    Luan, Yingzi; Jiang, Guang; Li, Jiandong

    2005-11-01

    MC-CDMA is a spectrum-efficient modulation in RF systems. Here it is used in optical wireless communications. Performance is simulated by using multiuser detection. Spatial Diversity is also considered and analyzed.

  4. Terahertz wireless communications based on photonics technologies.

    PubMed

    Nagatsuma, Tadao; Horiguchi, Shogo; Minamikata, Yusuke; Yoshimizu, Yasuyuki; Hisatake, Shintaro; Kuwano, Shigeru; Yoshimoto, Naoto; Terada, Jun; Takahashi, Hiroyuki

    2013-10-01

    There has been an increasing interest in the application of terahertz (THz) waves to broadband wireless communications. In particular, use of frequencies above 275 GHz is one of the strong concerns among radio scientists and engineers, because these frequency bands have not yet been allocated at specific active services, and there is a possibility to employ extremely large bandwidths for ultra-broadband wireless communications. Introduction of photonics technologies for signal generation, modulation and detection is effective not only to enhance the bandwidth and/or the data rate, but also to combine fiber-optic (wired) and wireless networks. This paper reviews recent progress in THz wireless communications using telecom-based photonics technologies towards 100 Gbit/s. PMID:24104286

  5. Visible Light Wireless Communication for Audio Signals

    NASA Astrophysics Data System (ADS)

    Vibin, A. M.; Prince, Shanthi

    2011-10-01

    In the current century there is an increased demand for broad band wireless access for satisfying different customer needs. These applications requires large amount of frequency resources for its efficient implementation. Radio Frequency techniques, which dominate the current wireless technology, have the limitation of available frequency spectrum that can be used. Researchers identified Optical Wireless Communication as a potential candidate for solving this problem. Studies shows that white light can also be used as a carrier for wireless communication and this area is generally known as Visible Light Communication. The provision of voice data and visual communications to users by using optical wireless has become a key area of research and product development. This paper discusses a novel method for transmission of voice in real time so that the system can be used for both communication and illumination simultaneously. A prototype of the system is implemented successfully and performance analyses are carried out based on the experimental results. SNR and BER calculations for the designed system is done theoretically and simulated. The developed system is having the advantages of very high band width, no interference with adjacent rooms as walls are opaque, no license is required as it doesn't cause electromagnetic interference and communication simultaneously with illumination.

  6. An underwater optical wireless communication network

    NASA Astrophysics Data System (ADS)

    Arnon, Shlomi

    2009-08-01

    The growing need for underwater observation and sub-sea 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, bio-geochemical, 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. We present models of three kinds of optical wireless communication links a) a line-of-sight link, b) a modulating retro-reflector 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 lighted it was possible to mitigate this decrease in some cases. We conclude 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.

  7. Analyzing Options for Airborne Emergency Wireless Communications

    SciTech Connect

    Michael Schmitt; Juan Deaton; Curt Papke; Shane Cherry

    2008-03-01

    In the event of large-scale natural or manmade catastrophic events, access to reliable and enduring commercial communication systems is critical. Hurricane Katrina provided a recent example of the need to ensure communications during a national emergency. To ensure that communication demands are met during these critical times, Idaho National Laboratory (INL) under the guidance of United States Strategic Command has studied infrastructure issues, concerns, and vulnerabilities associated with an airborne wireless communications capability. Such a capability could provide emergency wireless communications until public/commercial nodes can be systematically restored. This report focuses on the airborne cellular restoration concept; analyzing basic infrastructure requirements; identifying related infrastructure issues, concerns, and vulnerabilities and offers recommended solutions.

  8. FPGA-based rate-adaptive LDPC-coded modulation for the next generation of optical communication systems.

    PubMed

    Zou, Ding; Djordjevic, Ivan B

    2016-09-01

    In this paper, we propose a rate-adaptive FEC scheme based on LDPC codes together with its software reconfigurable unified FPGA architecture. By FPGA emulation, we demonstrate that the proposed class of rate-adaptive LDPC codes based on shortening with an overhead from 25% to 42.9% provides a coding gain ranging from 13.08 dB to 14.28 dB at a post-FEC BER of 10-15 for BPSK transmission. In addition, the proposed rate-adaptive LDPC coding combined with higher-order modulations have been demonstrated including QPSK, 8-QAM, 16-QAM, 32-QAM, and 64-QAM, which covers a wide range of signal-to-noise ratios. Furthermore, we apply the unequal error protection by employing different LDPC codes on different bits in 16-QAM and 64-QAM, which results in additional 0.5dB gain compared to conventional LDPC coded modulation with the same code rate of corresponding LDPC code. PMID:27607718

  9. Wireless communication and their mathematics

    NASA Astrophysics Data System (ADS)

    Komaki, Shozo

    2015-05-01

    Mobile phone and smart phone are penetrating into social use. To develop these system, various type of theoretical works based on mathematics are done, such as radio propagation theory, traffic theory, security coding and wireless device etc. In this speech, I will mention about the related mathematics and problems in it.

  10. Spin nano-oscillator-based wireless communication

    NASA Astrophysics Data System (ADS)

    Choi, Hyun Seok; Kang, Sun Yool; Cho, Seong Jun; Oh, Inn-Yeal; Shin, Mincheol; Park, Hyuncheol; Jang, Chaun; Min, Byoung-Chul; Kim, Sang-Il; Park, Seung-Young; Park, Chul Soon

    2014-06-01

    Spin-torque nano-oscillators (STNOs) have outstanding advantages of a high degree of compactness, high-frequency tunability, and good compatibility with the standard complementary metal-oxide-semiconductor process, which offer prospects for future wireless communication. There have as yet been no reports on wireless communication using STNOs, since the STNOs also have notable disadvantages such as lower output power and poorer spectral purity in comparison with those of LC voltage-controlled oscillators. Here we show that wireless communication is achieved by a proper choice of modulation scheme despite these drawbacks of STNOs. By adopting direct binary amplitude shift keying modulation and non-coherent demodulation, we demonstrate STNO-based wireless communication with 200-kbps data rate at a distance of 1 m between transmitter and receiver. It is shown, from the analysis of STNO noise, that the maximum data rate can be extended up to 1.48 Gbps with 1-ns turn-on time. For the fabricated STNO, the maximum data rate is 5 Mbps which is limited by the rise time measured in the total system. The result will provide a viable route to real microwave application of STNOs.

  11. Experimental validation of wireless communication with chaos.

    PubMed

    Ren, Hai-Peng; Bai, Chao; Liu, Jian; Baptista, Murilo S; Grebogi, Celso

    2016-08-01

    The constraints of a wireless physical media, such as multi-path propagation and complex ambient noises, prevent information from being communicated at low bit error rate. Surprisingly, it has only recently been shown that, from a theoretical perspective, chaotic signals are optimal for communication. It maximises the receiver signal-to-noise performance, consequently minimizing the bit error rate. This work demonstrates numerically and experimentally that chaotic systems can in fact be used to create a reliable and efficient wireless communication system. Toward this goal, we propose an impulsive control method to generate chaotic wave signals that encode arbitrary binary information signals and an integration logic together with the match filter capable of decreasing the noise effect over a wireless channel. The experimental validation is conducted by inputting the signals generated by an electronic transmitting circuit to an electronic circuit that emulates a wireless channel, where the signals travel along three different paths. The output signal is decoded by an electronic receiver, after passing through a match filter. PMID:27586613

  12. An Approach to Wireless Communications at Sandia National Laboratories

    SciTech Connect

    WITZKE, EDWARD L.

    2002-10-01

    Wireless communication plays an increasing role in military, industrial, public safety, and academic computer networks. Although in general, radio transmitters are not currently permitted in secured areas at Sandia, wireless communications would open new opportunities, allowing mobile and pervasive user access. Without wireless communications, we must live in a ''non-mainstream'' world of fixed, wired networks, where it becomes ever more difficult to attract and retain the best professionals. This report provides a review of the current state of wireless communications, which direction wireless technology is heading, and where wireless technology could be employed at Sandia. A list of recommendations on harnessing the power of wireless communications is provided to aid in building a state-of-the-art communication environment for the 21st century at Sandia.

  13. Low Frequency Wireless Communications Technology

    SciTech Connect

    Bartone, Erik J; Carbone, John F

    2004-01-27

    The purpose of this project was to demonstrate Nxegen's real-time wireless electricity monitoring and load management technologies in selected commercial, industrial, and municipal end user facilities. The purpose of which is to demonstrate the ability for Nxegen's technology to collect real-time electricity data to a central location (Nxegen's Network Operation Center "NOC"), aggregate customer load profiles into portfolios of profiles, and be able to dispatch load curtailment commands from the NOC to individual customer loads to demonstrate the ability to integrate demand resources into the overall electric utility system for the purpose of; (1) improving overall system reliability, (2) reducing wholesale electric generation prices (locational marginal prices "LMP"), and (3) reducing congestion costs in energy constrained areas (southwest Connecticut).

  14. Wireless Network Communications Overview for Space Mission Operations

    NASA Technical Reports Server (NTRS)

    Fink, Patrick W.

    2009-01-01

    The mission of the On-Board Wireless Working Group (WWG) is to serve as a general CCSDS focus group for intra-vehicle wireless technologies. The WWG investigates and makes recommendations pursuant to standardization of applicable wireless network protocols, ensuring the interoperability of independently developed wireless communication assets. This document presents technical background information concerning uses and applicability of wireless networking technologies for space missions. Agency-relevant driving scenarios, for which wireless network communications will provide a significant return-on-investment benefiting the participating international agencies, are used to focus the scope of the enclosed technical information.

  15. Automobile inspection system based on wireless communication

    NASA Astrophysics Data System (ADS)

    Miao, Changyun; Ye, Chunqing

    2010-07-01

    This paper aims to research the Automobile Inspection System based on Wireless Communication, and suggests an overall design scheme which uses GPS for speed detection and Bluetooth and GPRS for communication. The communication between PDA and PC was realized by means of GPRS and TCP/IP; and the hardware circuit and software for detection terminal were devised by means of JINOU-3264 Bluetooth Module after analyzing the Bluetooth and its communication protocol. According to the results of debugging test, this system accomplished GPRS based data communication and management as well as the real-time detection on auto safety performance parameters in crash test via PC, whereby the need for mobility and reliability was met and the efficiency and level of detection was improved.

  16. 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

    ... and Battery Packs; Notice of Investigation AGENCY: U.S. International Trade Commission. ACTION... server software, wireless handheld devices and battery packs by reason of infringement of certain claims... importation of certain wireless communications system server software, wireless handheld devices or...

  17. Energy efficiency in wireless communication systems

    DOEpatents

    Caffrey, Michael Paul; Palmer, Joseph McRae

    2012-12-11

    Wireless communication systems and methods utilize one or more remote terminals, one or more base terminals, and a communication channel between the remote terminal(s) and base terminal(s). The remote terminal applies a direct sequence spreading code to a data signal at a spreading factor to provide a direct sequence spread spectrum (DSSS) signal. The DSSS signal is transmitted over the communication channel to the base terminal which can be configured to despread the received DSSS signal by a spreading factor matching the spreading factor utilized to spread the data signal. The remote terminal and base terminal can dynamically vary the matching spreading factors to adjust the data rate based on an estimation of operating quality over time between the remote terminal and base terminal such that the amount of data being transmitted is substantially maximized while providing a specified quality of service.

  18. Wireless communication system via nanoscale plasmonic antennas

    PubMed Central

    Merlo, Juan M.; Nesbitt, Nathan T.; Calm, Yitzi M.; Rose, Aaron H.; D’Imperio, Luke; Yang, Chaobin; Naughton, Jeffrey R.; Burns, Michael J.; Kempa, Krzysztof; Naughton, Michael J.

    2016-01-01

    Present on-chip optical communication technology uses near-infrared light, but visible wavelengths would allow system miniaturization and higher energy confinement. Towards this end, we report a nanoscale wireless communication system that operates at visible wavelengths via in-plane information transmission. Here, plasmonic antenna radiation mediates a three-step conversion process (surface plasmon → photon → surface plasmon) with in-plane efficiency (plasmon → plasmon) of 38% for antenna separation 4λ0 (with λ0 the free-space excitation wavelength). Information transmission is demonstrated at bandwidths in the Hz and MHz ranges. This work opens the possibility of optical conveyance of information using plasmonic antennas for on-chip communication technology. PMID:27555451

  19. Wireless communication system via nanoscale plasmonic antennas.

    PubMed

    Merlo, Juan M; Nesbitt, Nathan T; Calm, Yitzi M; Rose, Aaron H; D'Imperio, Luke; Yang, Chaobin; Naughton, Jeffrey R; Burns, Michael J; Kempa, Krzysztof; Naughton, Michael J

    2016-01-01

    Present on-chip optical communication technology uses near-infrared light, but visible wavelengths would allow system miniaturization and higher energy confinement. Towards this end, we report a nanoscale wireless communication system that operates at visible wavelengths via in-plane information transmission. Here, plasmonic antenna radiation mediates a three-step conversion process (surface plasmon → photon → surface plasmon) with in-plane efficiency (plasmon → plasmon) of 38% for antenna separation 4λ0 (with λ0 the free-space excitation wavelength). Information transmission is demonstrated at bandwidths in the Hz and MHz ranges. This work opens the possibility of optical conveyance of information using plasmonic antennas for on-chip communication technology. PMID:27555451

  20. Ergodic capacity comparison of optical wireless communications using adaptive transmissions.

    PubMed

    Hassan, Md Zoheb; Hossain, Md Jahangir; Cheng, Julian

    2013-08-26

    Ergodic capacity is investigated for the optical wireless communications employing subcarrier intensity modulation with direct detection, and coherent systems with and without polarization multiplexing over the Gamma-Gamma turbulence channels. We consider three different adaptive transmission schemes: (i) variable-power, variable-rate adaptive transmission, (ii) complete channel inversion with fixed rate, and (iii) truncated channel inversion with fixed rate. For the considered systems, highly accurate series expressions for ergodic capacity are derived using a series expansion of the modified Bessel function and the Mellin transformation of the Gamma-Gamma random variable. Our asymptotic analysis reveals that the high SNR ergodic capacities of coherent, subcarrier intensity modulated, and polarization multiplexing systems gain 0.33 bits/s/Hz, 0.66 bits/s/Hz, and 0.66 bits/s/Hz respectively with 1 dB increase of average transmitted optical power. Numerical results indicate that a polarization control error less than 10° has little influence on the capacity performance of polarization multiplexing systems. PMID:24105580

  1. 75 FR 68619 - In the Matter of Certain Wireless Communication Devices, Portable Music and Data Processing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-08

    ... COMMISSION In the Matter of Certain Wireless Communication Devices, Portable Music and Data Processing... certain wireless communication devices, portable music and data processing devices, computers and... certain wireless communication devices, portable music and data processing devices, computers...

  2. 77 FR 58576 - Certain Wireless Communication Devices, Portable Music and Data Processing Devices, Computers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-21

    ... COMMISSION Certain Wireless Communication Devices, Portable Music and Data Processing Devices, Computers, and... importation of certain wireless communication devices, portable music and data processing devices, computers... after importation of certain wireless communication devices, portable music and data processing...

  3. 78 FR 6837 - Certain Wireless Communications Equipment and Articles Therein; Institution of Investigation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-31

    ... COMMISSION Certain Wireless Communications Equipment and Articles Therein; Institution of Investigation... States after importation of certain wireless communications equipment and articles therein by reason of... importation of certain wireless communications equipment and articles therein by reason of infringement of...

  4. 78 FR 1247 - Certain Electronic Devices, Including Wireless Communication Devices, Tablet Computers, Media...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-08

    ... COMMISSION Certain Electronic Devices, Including Wireless Communication Devices, Tablet Computers, Media... United States after importation of certain electronic devices, including wireless communication devices... importation of certain electronic devices, including wireless communication devices, tablet computers,...

  5. Wireless Intra-Spacecraft Communication: The Benefits and the Challenges

    NASA Technical Reports Server (NTRS)

    Zheng, Will H.; Armstrong, John T.

    2010-01-01

    In this paper we present a systematic study of how intra-spacecraft wireless communication can be adopted to various subsystems of the spacecraft including C&DH (Command & Data Handling), Telecom, Power, Propulsion, and Payloads, and the interconnects between them. We discuss the advantages of intra-spacecraft wireless communication and the disadvantages and challenges and a proposal to address them.

  6. Affordable underwater wireless optical communication using LEDs

    NASA Astrophysics Data System (ADS)

    Pilipenko, Vladimir; Arnon, Shlomi

    2013-09-01

    In recent years the need for high data rate underwater wireless communication (WC) has increased. Nowadays, the conventional technology for underwater communication is acoustic. However, the maximum data rate that acoustic technology can provide is a few kilobits per second. On the other hand, emerging applications such as underwater imaging, networks of sensors and swarms of underwater vehicles require much faster data rates. As a result, underwater optical WC, which can provide much higher data rates, has been proposed as an alternative means of communication. In addition to high data rates, affordable communication systems become an important feature in the development requirements. The outcome of these requirements is a new system design based on off-the-shelf components such as blue and green light emitting diodes (LEDs). This is due to the fact that LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness. However, there are some challenges to be met when incorporating LEDs as part of the optical transmitter, such as low modulation rates and non linearity. In this paper, we review the main challenges facing the incorporation of LEDs as an integral part of underwater WC systems and propose some techniques to mitigate the LED limitations in order to achieve high data rate communication

  7. Energy neutral and low power wireless communications

    NASA Astrophysics Data System (ADS)

    Orhan, Oner

    Wireless sensor nodes are typically designed to have low cost and small size. These design objectives impose restrictions on the capacity and efficiency of the transceiver components and energy storage units that can be used. As a result, energy becomes a bottleneck and continuous operation of the sensor network requires frequent battery replacements, increasing the maintenance cost. Energy harvesting and energy efficient transceiver architectures are able to overcome these challenges by collecting energy from the environment and utilizing the energy in an intelligent manner. However, due to the nature of the ambient energy sources, the amount of useful energy that can be harvested is limited and unreliable. Consequently, optimal management of the harvested energy and design of low power transceivers pose new challenges for wireless network design and operation. The first part of this dissertation is on energy neutral wireless networking, where optimal transmission schemes under different system setups and objectives are investigated. First, throughput maximization for energy harvesting two-hop networks with decode-and-forward half-duplex relays is studied. For a system with two parallel relays, various combinations of the following four transmission modes are considered: Broadcast from the source, multi-access from the relays, and successive relaying phases I and II. Next, the energy cost of the processing circuitry as well as the transmission energy are taken into account for communication over a broadband fading channel powered by an energy harvesting transmitter. Under this setup, throughput maximization, energy maximization, and transmission completion time minimization problems are studied. Finally, source and channel coding for an energy-limited wireless sensor node is investigated under various energy constraints including energy harvesting, processing and sampling costs. For each objective, optimal transmission policies are formulated as the solutions of a

  8. Phase patterns of coupled oscillators with application to wireless communication

    SciTech Connect

    Arenas, A.

    2008-01-02

    Here we study the plausibility of a phase oscillators dynamical model for TDMA in wireless communication networks. We show that emerging patterns of phase locking states between oscillators can eventually oscillate in a round-robin schedule, in a similar way to models of pulse coupled oscillators designed to this end. The results open the door for new communication protocols in a continuous interacting networks of wireless communication devices.

  9. 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.

  10. Wireless infrared communications for space and terrestrial applications

    NASA Technical Reports Server (NTRS)

    Crimmins, James W.

    1993-01-01

    Voice and data communications via wireless (and fiberless) optical means has been commonplace for many years. However, continuous advances in optoelectronics and microelectronics have resulted in significant advances in wireless optical communications over the last decade. Wilton has specialized in diffuse infrared voice and data communications since 1979. In 1986, NASA Johnson Space Center invited Wilton to apply its wireless telecommunications and factory floor technology to astronaut voice communications aboard the shuttle. In September, 1988 a special infrared voice communications system flew aboard a 'Discovery' Shuttle mission as a flight experiment. Since then the technology has been further developed, resulting in a general purpose of 2Mbs wireless voice/data LAN which has been tested for a variety of applications including use aboard Spacelab. Funds for Wilton's wireless IR development were provided in part by NASA's Technology Utilization Office and by the NASA Small Business Innovative Research Program. As a consequence, Wilton's commercial product capability has been significantly enhanced to include diffuse infrared wireless LAN's as well as wireless infrared telecommunication systems for voice and data.

  11. Spherical transceivers for ultrafast optical wireless communications

    NASA Astrophysics Data System (ADS)

    Jin, Xian; Hristovski, Blago A.; Collier, Christopher M.; Geoffroy-Gagnon, Simon; Born, Brandon; Holzman, Jonathan F.

    2016-02-01

    Optical wireless communications (OWC) offers the potential for high-speed and mobile operation in indoor networks. Such OWC systems often employ a fixed transmitter grid and mobile transceivers, with the mobile transceivers carrying out bi-directional communication via active downlinks (ideally with high-speed signal detection) and passive uplinks (ideally with broad angular retroreflection and high-speed modulation). It can be challenging to integrate all of these bidirectional communication capabilities within the mobile transceivers, however, as there is a simultaneous desire for compact packaging. With this in mind, the work presented here introduces a new form of transceiver for bi-directional OWC systems. The transceiver incorporates radial photoconductive switches (for high-speed signal detection) and a spherical retro-modulator (for broad angular retroreflection and high-speed all-optical modulation). All-optical retromodulation are investigated by way of theoretical models and experimental testing, for spherical retro-modulators comprised of three glasses, N-BK7, N-LASF9, and S-LAH79, having differing levels of refraction and nonlinearity. It is found that the spherical retro-modulator comprised of S-LAH79, with a refractive index of n ≍ 2 and a Kerr nonlinear index of n2 ≍ (1.8 ± 0.1) × 10-15 cm2/W, yields both broad angular retroreflection (over a solid angle of 2π steradians) and ultrafast modulation (over a duration of 120 fs). Such transceivers can become important elements for all-optical implementations in future bi-directional OWC systems.

  12. Tradeoff Analysis for Combat Service Support Wireless Communications Alternatives

    SciTech Connect

    Burnette, John R.; Thibodeau, Christopher C.; Greitzer, Frank L.

    2002-02-28

    As the Army moves toward more mobile and agile forces and continued sustainment of numerous high-cost legacy logistics management systems, the requirement for wireless connectivity and a wireless network to supporting organizations has become ever more critical. There are currently several Army communications initiatives underway to resolve this wireless connectivity issue. However, to fully appreciate and understand the value of these initiatives, a Tradeoff Analysis is needed. The present study seeks to identify and assess solutions. The analysis identified issues that impede Interim Brigade Combat Team (IBCT) communication system integration and outlined core requirements for sharing of logistics data between the field and Army battle command systems. Then, the analysis examined wireless communication alternatives as possible solutions for IBCT logistics communications problems. The current baseline system was compared with possible alternatives involving tactical radio systems, wireless/near term digital radio, cellular satellite, and third-generation (3G) wireless technologies. Cellular satellite and 3G wireless technologies offer clear advantages and should be considered for later IBCTs.

  13. 77 FR 51571 - Certain Wireless Communication Devices, Portable Music and Data Processing Devices, Computers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-24

    ... COMMISSION Certain Wireless Communication Devices, Portable Music and Data Processing Devices, Computers, and.... International Trade Commission has received a complaint entitled Wireless Communication Devices, Portable Music... communication devices, portable music and data processing devices, computers, and components thereof....

  14. 78 FR 115 - Certain Wireless Communications Equipment and Articles Therein; Notice of Receipt of Complaint...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-02

    ... COMMISSION Certain Wireless Communications Equipment and Articles Therein; Notice of Receipt of Complaint... Communications Equipment and Articles Therein, DN 2926; the Commission is soliciting comments on any public... within the United States after importation of certain wireless communications equipment and...

  15. Secure Wireless Communications via Cooperative Transmitting

    PubMed Central

    Stojanovski, Toni Draganov; Marina, Ninoslav

    2014-01-01

    Information-theoretic secrecy is combined with cryptographic secrecy to create a secret-key exchange protocol for wireless networks. A network of transmitters, which already have cryptographically secured channels between them, cooperate to exchange a secret key with a new receiver at a random location, in the presence of passive eavesdroppers at unknown locations. Two spatial point processes, homogeneous Poisson process and independent uniformly distributed points, are used for the spatial distributions of transmitters and eavesdroppers. We analyse the impact of the number of cooperating transmitters and the number of eavesdroppers on the area fraction where secure communication is possible. Upper bounds on the probability of existence of positive secrecy between the cooperating transmitters and the receiver are derived. The closeness of the upper bounds to the real value is then estimated by means of numerical simulations. Simulations also indicate that a deterministic spatial distribution for the transmitters, for example, hexagonal and square lattices, increases the probability of existence of positive secrecy capacity compared to the random spatial distributions. For the same number of friendly nodes, cooperative transmitting provides a dramatically larger secrecy region than cooperative jamming and cooperative relaying. PMID:24711735

  16. Secure wireless communications via cooperative transmitting.

    PubMed

    Stojanovski, Toni Draganov; Marina, Ninoslav

    2014-01-01

    Information-theoretic secrecy is combined with cryptographic secrecy to create a secret-key exchange protocol for wireless networks. A network of transmitters, which already have cryptographically secured channels between them, cooperate to exchange a secret key with a new receiver at a random location, in the presence of passive eavesdroppers at unknown locations. Two spatial point processes, homogeneous Poisson process and independent uniformly distributed points, are used for the spatial distributions of transmitters and eavesdroppers. We analyse the impact of the number of cooperating transmitters and the number of eavesdroppers on the area fraction where secure communication is possible. Upper bounds on the probability of existence of positive secrecy between the cooperating transmitters and the receiver are derived. The closeness of the upper bounds to the real value is then estimated by means of numerical simulations. Simulations also indicate that a deterministic spatial distribution for the transmitters, for example, hexagonal and square lattices, increases the probability of existence of positive secrecy capacity compared to the random spatial distributions. For the same number of friendly nodes, cooperative transmitting provides a dramatically larger secrecy region than cooperative jamming and cooperative relaying. PMID:24711735

  17. 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.

  18. A wireless diabetes management and communication system.

    PubMed

    Vigersky, Robert A; Hanson, Eric; McDonough, Edward; Rapp, Timothy; Pajak, John; Galen, Robert S

    2003-01-01

    Current diabetes management requires the collection of a large volume of data by the patient for analysis by his or her provider. There are numerous practical and technical barriers to doing this effectively and efficiently. In addition, the calculation of the correct insulin dose is complex because it requires considering anticipated carbohydrate consumption and exercise in addition to the current blood glucose level. A Diabetes Management and Communication System (DMCS) has been developed using a Compaq iPAQ Pocket PC with a Sprint PCS wireless AirCard. This system circumvents the problem of multiple proprietary programs for each brand of meter and permits the accurate determination of the proper insulin dose. Privacy is maintained by using only the iPAQ serial number as the patient identifier with access to the website protected by unique patient and provider passwords. The iPAQ was programmed with formulas that included: insulin sensitivity factor, current glucose level, amount of carbohydrates, appropriate carbohydrate:insulin ratio for that meal, and duration/intensity of exercise. Once the information is entered, an insulin dose is calculated, although an alternative dose can be selected. The data are downloaded to http://www.HealthSentry.net, where they are displayed in both tabular and graphic form. The patient may view the glucose data in both tabular and graphic form on the iPAQ. Thus a DMCS has been developed to assist patients and providers in improving glycemic control. A proof-of-concept study is underway to determine the effectiveness of the DMCS in patients with Type 1 diabetes mellitus who are currently using insulin pumps. PMID:14511424

  19. Remote monitoring system research and implementation based on wireless communication

    NASA Astrophysics Data System (ADS)

    Fu, Weizhi; Meng, Xiaofeng

    2013-03-01

    With rapid development of automatic control and network techniques, network-based remote monitoring is becoming an investigating hotspot in the elevator industry. At the same time as the development of wireless communication technology, remote wireless monitoring technology is applied more and more widely in recent years. A variety of wireless detection equipment is entering various industrial enterprises, and has been widely used. At present, there are many defects of the traditional monitoring system, such as poor real-time, low reliability, low intelligence. Based on the analysis of the difficulties to monitor the mobile terminal, this paper firstly analyzes the GSM/GPRS technology, and then discusses a design of the remote monitoring system based on wireless communication. The architecture of the monitoring center is introduced in detail. It is characterized by user-friendly, easy operate, good real-time and easy to extend.

  20. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  1. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  2. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  3. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  4. 49 CFR 220.37 - Testing radio and wireless communication equipment.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Testing radio and wireless communication equipment... RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD COMMUNICATIONS Radio and Wireless Communication Procedures § 220.37 Testing radio and wireless communication equipment. (a) Each radio, and...

  5. Intelligent sensing and wireless communications in harsh environments

    NASA Astrophysics Data System (ADS)

    Pereira, Carlos M.; Mattice, Michael S.; Testa, Robert C.

    2000-06-01

    The objective of this paper is to focus on recent efforts to test and characterize the performance of MEMS inertial sensors and the characterization of battery-free embedded sensors in munitions. This paper will also discuss the need to implement and integrate internal wireless communications in conjunction with smart electronics and smart materials in innovative microelectronics designs with built in capability of duplex wireless communications between sensors and telemetry. Embedded wireless telemetry will eliminate wires and the stress on long wire runs between MEMS sensor and processing microelectronics in harsh environments. Further advancements in this wireless area will facilitate the integration of smart sensing, control and actuation with unprecedented capability to permanently embed telemetry as a part of the standard munition components. The embedded wireless telemetry would have built in capability for smart munitions stockpile surveillance, in-flight duplex communication and the capability to communicate to a ground station. Future telemetry links for munitions will have a significant multi-use capability, designed to measure, maintain reliability, predictive surveillance, actuation and remote control functionality.

  6. The role of wireless communications in the National Information Infrastructure

    SciTech Connect

    Backof, C.A.

    1995-08-01

    We live today in a communications world of private voice and public images. The telephone provides private voice contact, while television delivers public broadcast images. With the National Information Infrastructure (NII), that communications model will expand to include private and public access to all forms of information, supporting services and products that can only be imagined. The model is however constrained to fit a wired format, even though people have come to expect wireless access. This paper explores the applications and technologies needed to extend the NII with broadband wireless access, and presents estimates of the spectrum required to achieve this extension.

  7. How Much Longer before It All Works: What Online Searchers Should Know about Wireless Data Communications.

    ERIC Educational Resources Information Center

    Bell, Steven J.

    1994-01-01

    Profiles the major wireless data communications (WDC) systems, provides an overview of how they work, and compares their communication features. Topics addressed include the market for wireless data; applications for WDC; wireless online searching; cellular data communication; packet radio; digital cellular; criteria for evaluating WDC systems;…

  8. Implantable Radio Frequency Identification Sensors: Wireless Power and Communication

    PubMed Central

    Hutchens, Chriswell; Rennaker, Robert L.; Venkataraman, Srinivasan; Ahmed, Rehan; Liao, Ran; Ibrahim, Tamer

    2013-01-01

    There are significant technical challenges in the development of a fully implantable wirelessly powered neural interface. Challenges include wireless transmission of sufficient power to the implanted device to ensure reliable operation for decades without replacement, minimizing tissue heating, and adequate reliable communications bandwidth. Overcoming these challenges is essential for the development of implantable closed loop system for the treatment of disorders ranging from epilepsy, incontinence, stroke and spinal cord injury. We discuss the development of the wireless power, communication and control for a Radio-Frequency Identification Sensor (RFIDS) system with targeted power range for a 700mV, 30 to 40uA load attained at −2dBm. PMID:22254944

  9. Implantable radio frequency identification sensors: wireless power and communication.

    PubMed

    Hutchens, Chriswell; Rennaker, Robert L; Venkataraman, Srinivasan; Ahmed, Rehan; Liao, Ran; Ibrahim, Tamer

    2011-01-01

    There are significant technical challenges in the development of a fully implantable wirelessly powered neural interface. Challenges include wireless transmission of sufficient power to the implanted device to ensure reliable operation for decades without replacement, minimizing tissue heating, and adequate reliable communications bandwidth. Overcoming these challenges is essential for the development of implantable closed loop system for the treatment of disorders ranging from epilepsy, incontinence, stroke and spinal cord injury. We discuss the development of the wireless power, communication and control for a Radio-Frequency Identification Sensor (RFIDS) system with targeted power range for a 700 mV, 30 to 40 uA load attained at -2 dBm. PMID:22254944

  10. 75 FR 43088 - Personal Communications Services and Miscellaneous Wireless Communications Services

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-23

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 24 and 27 Personal Communications Services and Miscellaneous Wireless Communications Services CFR Correction In Title 47 of the Code of Federal Regulations, Parts 20 to 39, revised as...

  11. Underwater Wireless Optical Communication System Using Blue LEDs

    NASA Astrophysics Data System (ADS)

    Lin, Aobo; Tong, Zheng; Song, Yuhang; Kong, Meiwei; Xu, Jing

    2016-02-01

    We demonstrate a self-designed underwater wireless optical communication system using blue LEDs. The performance of the transmitter and receiver was experimentally investigated. Four different square wave signals (10 KHz, 100 KHz, 500 KHz and 1 MHz) were successfully transmitted via a short water channel at the first phase.

  12. Experimental wavelet based denoising for indoor infrared wireless communications.

    PubMed

    Rajbhandari, Sujan; Ghassemlooy, Zabih; Angelova, Maia

    2013-06-01

    This paper reports the experimental wavelet denoising techniques carried out for the first time for a number of modulation schemes for indoor optical wireless communications in the presence of fluorescent light interference. The experimental results are verified using computer simulations, clearly illustrating the advantage of the wavelet denoising technique in comparison to the high pass filtering for all baseband modulation schemes. PMID:23736631

  13. Teaching the Fundamentals of Cell Phones and Wireless Communications

    ERIC Educational Resources Information Center

    Davids, Mark; Forrest, Rick; Pata, Don

    2010-01-01

    Wireless communications are ubiquitous. Students and teachers use iPhones[R], BlackBerrys[R], and other smart phones at home and at work. More than 275 million Americans had cell phones in June of 2009 and expanded access to broadband is predicted this year. Despite the plethora of users, most students and teachers do not understand "how they…

  14. 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

    ..., 2010, based on a complaint filed by Motorola, Inc. (``Motorola'') of Schaumburg, Illinois. 75 FR 8401... and Battery Packs: Notice of Commission Determination Not To Review An Initial Determination... communications system server software, wireless handheld devices and battery packs by reason of infringement...

  15. A Survey of Wireless Communications for the Electric Power System

    SciTech Connect

    Akyol, Bora A.; Kirkham, Harold; Clements, Samuel L.; Hadley, Mark D.

    2010-01-27

    A key mission of the U.S. Department of Energy (DOE) Office of Electricity Delivery and Energy Reliability (OE) is to enhance the security and reliability of the nation’s energy infrastructure. Improving the security of control systems, which enable the automated control of our energy production and distribution, is critical for protecting the energy infrastructure and the integral function that it serves in our lives. The DOE-OE Control Systems Security Program provides research and development to help the energy industry actively pursue advanced security solutions for control systems. The focus of this report is analyzing how, where, and what type of wireless communications are suitable for deployment in the electric power system and to inform implementers of their options in wireless technologies. The discussions in this report are applicable to enhancing both the communications infrastructure of the current electric power system and new smart system deployments. The work described in this report includes a survey of the following wireless technologies: • IEEE 802.16 d and e (WiMAX) • IEEE 802.11 (Wi-Fi) family of a, b, g, n, and s • Wireless sensor protocols that use parts of the IEEE 802.15.4 specification: WirelessHART, International Society of Automation (ISA) 100.11a, and Zigbee • The 2, 3, and 4 generation (G )cellular technologies of GPRS/EDGE/1xRTT, HSPA/EVDO, and Long-Term Evolution (LTE)/HSPA+UMTS.

  16. 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.

  17. Distributed wireless quantum communication networks with partially entangled pairs

    NASA Astrophysics Data System (ADS)

    Yu, Xu-Tao; Zhang, Zai-Chen; Xu, Jin

    2014-01-01

    Wireless quantum communication networks transfer quantum state by teleportation. Existing research focuses on maximal entangled pairs. In this paper, we analyse the distributed wireless quantum communication networks with partially entangled pairs. A quantum routing scheme with multi-hop teleportation is proposed. With the proposed scheme, is not necessary for the quantum path to be consistent with the classical path. The quantum path and its associated classical path are established in a distributed way. Direct multi-hop teleportation is conducted on the selected path to transfer a quantum state from the source to the destination. Based on the feature of multi-hop teleportation using partially entangled pairs, if the node number of the quantum path is even, the destination node will add another teleportation at itself. We simulated the performance of distributed wireless quantum communication networks with a partially entangled state. The probability of transferring the quantum state successfully is statistically analyzed. Our work shows that multi-hop teleportation on distributed wireless quantum networks with partially entangled pairs is feasible.

  18. Study and design on USB wireless laser communication system

    NASA Astrophysics Data System (ADS)

    Wang, Aihua; Zheng, Jiansheng; Ai, Yong

    2004-04-01

    We give the definition of USB wireless laser communication system (WLCS) and the brief introduction to the protocol of USB, the standard of hardware is also given. The paper analyses the hardware and software of USB WLCS. Wireless laser communication part and USB interface circuit part are discussed in detail. We also give the periphery design of the chip AN2131Q, the control circuit to realize the transformation from parallel port to serial bus, and the circuit of laser sending and receiving of laser communication part, which are simply, cheap and workable. And then the four part of software are analyzed as followed. We have consummated the ISR in the firmware frame to develop the periphery device of USB. We have debugged and consummated the 'ezload,' and the GPD of the drivers. Windows application performs functions and schedules the corresponding API functions to let the interface practical and beautiful. The system can realize USB wireless laser communication between computers, which distance is farther than 50 meters, and top speed can be bigger than 8 Mbps. The system is of great practical sense to resolve the issues of high-speed communication among increasing districts without fiber trunk network.

  19. 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

  20. 77 FR 37732 - Fourteenth Meeting: RTCA Special Committee 223, Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-22

    ... Federal Aviation Administration Fourteenth Meeting: RTCA Special Committee 223, Airport Surface Wireless...: Meeting Notice of RTCA Special Committee 223, Airport Surface Wireless Communications. SUMMARY: The FAA is... Wireless Communications. DATES: The meeting will be held July 24-25, 2012, from 9 a.m.-5 p.m....

  1. 76 FR 20436 - Ninth Meeting: RTCA Special Committee 223: Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-12

    ... Federal Aviation Administration Ninth Meeting: RTCA Special Committee 223: Airport Surface Wireless... of RTCA Special Committee 223: Airport Surface Wireless Communications meeting. SUMMARY: The FAA is... Wireless Communications. DATES: The meeting will be held May 3-5, 2011 from 9 a.m. to 5 p.m. ADDRESSES:...

  2. 75 FR 66423 - Seventh Meeting: RTCA Special Committee 223: Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-28

    ... Federal Aviation Administration Seventh Meeting: RTCA Special Committee 223: Airport Surface Wireless... of RTCA Special Committee 223: Airport Surface Wireless Communications meeting. SUMMARY: The FAA is... Wireless Communications. DATES: The meeting will be held November 16-17, 2010 from 9 a.m.-5 p.m....

  3. 75 FR 14483 - Third Meeting: RTCA Special Committee 223: Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-25

    ... Federal Aviation Administration Third Meeting: RTCA Special Committee 223: Airport Surface Wireless...: Airport Surface Wireless Communications meeting. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 223: Airport Surface Wireless Communications. DATES:...

  4. 77 FR 55894 - Thirteenth Meeting: RTCA Special Committee 223, Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ... Federal Aviation Administration Thirteenth Meeting: RTCA Special Committee 223, Airport Surface Wireless...: Meeting Notice of RTCA Special Committee 223, Airport Surface Wireless Communications. SUMMARY: The FAA is..., Airport Surface Wireless Communications. DATES: The meeting will be held October 2-3, 2012, from 9...

  5. 75 FR 54421 - Sixth Meeting: RTCA Special Committee 223: Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-07

    ... Federal Aviation Administration Sixth Meeting: RTCA Special Committee 223: Airport Surface Wireless... of RTCA Special Committee 223: Airport Surface Wireless Communications meeting. SUMMARY: The FAA is... Wireless Communications. DATES: The meeting will be held September 28-30, 2010 from 0900 a.m.- 1600...

  6. 75 FR 30899 - Fourth Meeting: RTCA Special Committee 223: Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-02

    ... Federal Aviation Administration Fourth Meeting: RTCA Special Committee 223: Airport Surface Wireless...: Airport Surface Wireless Communications meeting. SUMMARY: The FAA is issuing this notice to advise the public of a meeting of RTCA Special Committee 223: Airport Surface Wireless Communications. DATES:...

  7. 76 FR 6179 - Eighth Meeting: RTCA Special Committee 223: Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-03

    ... Federal Aviation Administration Eighth Meeting: RTCA Special Committee 223: Airport Surface Wireless... of RTCA Special Committee 223: Airport Surface Wireless Communications meeting. SUMMARY: The FAA is... Wireless Communications. DATES: The meeting will be held February 22-23, 2011 from 9 a.m. to 5...

  8. 76 FR 38740 - Tenth Meeting: RTCA Special Committee 223: Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... Federal Aviation Administration Tenth Meeting: RTCA Special Committee 223: Airport Surface Wireless... of RTCA Special Committee 223: Airport Surface Wireless Communications meeting. SUMMARY: The FAA is... Wireless Communications. DATES: The meeting will be held August 9-10, 2011 from 9 a.m. to 5 p.m....

  9. 77 FR 71028 - Twelfth Meeting: RTCA Special Committee 223, Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-28

    ... Federal Aviation Administration Twelfth Meeting: RTCA Special Committee 223, Airport Surface Wireless...: Meeting Notice of RTCA Special Committee 223, Airport Surface Wireless Communications. SUMMARY: The FAA is... Wireless Communications. DATES: The meeting will be held December 4-6, 2012, from 9:00 a.m.-5:00...

  10. Study of wireless communication between MEMS sensing nodes

    NASA Astrophysics Data System (ADS)

    Rivera, José; Saafi, Mohamed; Heidary, Kaveh

    2006-05-01

    Wireless sensors networks are currently being used in different engineering fields such as civil, mechanical and aerospace engineering for damage detection. Each network contains approximately hundreds to thousands of MEMS sensors that communicate to its base station. These sensors are placed in different environments and locations that create changes in their output due to obstacles or interference between them and their base station. A research study was conducted on wireless MEMS sensor nodes to evaluate the noise level and the effect of environmental interferences as well as their maximum distance communication. In this paper, the effect of interference environments and obstacles such as magnetic field created by electricity and cell phone communications, concrete and metal enclosures, and outside/inside environments were evaluated. In addition, a neural network computer simulation was developed to learn and teach the users what it takes to classify signals such as time, amount of samples and overtraining in order to obtain the correct output instead of an unknown. By gathering all this information it helps to save money and time in any application wireless MEMS sensors are used and idealized models and pictures of communication paths have been created for easier evaluation of the MEMS sensor networks.

  11. Open-Source Telemedicine Platform for Wireless Medical Video Communication

    PubMed Central

    Panayides, A.; Eleftheriou, I.; Pantziaris, M.

    2013-01-01

    An m-health system for real-time wireless communication of medical video based on open-source software is presented. The objective is to deliver a low-cost telemedicine platform which will allow for reliable remote diagnosis m-health applications such as emergency incidents, mass population screening, and medical education purposes. The performance of the proposed system is demonstrated using five atherosclerotic plaque ultrasound videos. The videos are encoded at the clinically acquired resolution, in addition to lower, QCIF, and CIF resolutions, at different bitrates, and four different encoding structures. Commercially available wireless local area network (WLAN) and 3.5G high-speed packet access (HSPA) wireless channels are used to validate the developed platform. Objective video quality assessment is based on PSNR ratings, following calibration using the variable frame delay (VFD) algorithm that removes temporal mismatch between original and received videos. Clinical evaluation is based on atherosclerotic plaque ultrasound video assessment protocol. Experimental results show that adequate diagnostic quality wireless medical video communications are realized using the designed telemedicine platform. HSPA cellular networks provide for ultrasound video transmission at the acquired resolution, while VFD algorithm utilization bridges objective and subjective ratings. PMID:23573082

  12. An Overview of the Recent Wideband Transcutaneous Wireless Communication Techniques

    PubMed Central

    Ghovanloo, Maysam

    2013-01-01

    Neuroprosthetic devices such as cochlear and retinal implants need to deliver a large volume of data from external sensors into the body, while invasive brain-computer interfaces need to deliver sizeable amounts of data from the central nervous system to target devices outside of the body. Nonetheless, the skin should remain intact. This paper reviews some of the latest techniques to establish wideband wireless communication links across the skin. PMID:22255673

  13. Streetlight Control System Based on Wireless Communication over DALI Protocol.

    PubMed

    Bellido-Outeiriño, Francisco José; Quiles-Latorre, Francisco Javier; Moreno-Moreno, Carlos Diego; Flores-Arias, José María; Moreno-García, Isabel; Ortiz-López, Manuel

    2016-01-01

    Public lighting represents a large part of the energy consumption of towns and cities. Efficient management of public lighting can entail significant energy savings. This work presents a smart system for managing public lighting networks based on wireless communication and the DALI protocol. Wireless communication entails significant economic savings, as there is no need to install new wiring and visual impacts and damage to the facades of historical buildings in city centers are avoided. The DALI protocol uses bidirectional communication with the ballast, which allows its status to be controlled and monitored at all times. The novelty of this work is that it tackles all aspects related to the management of public lighting: a standard protocol, DALI, was selected to control the ballast, a wireless node based on the IEEE 802.15.4 standard with a DALI interface was designed, a network layer that considers the topology of the lighting network has been developed, and lastly, some user-friendly applications for the control and maintenance of the system by the technical crews of the different towns and cities have been developed. PMID:27128923

  14. Streetlight Control System Based on Wireless Communication over DALI Protocol

    PubMed Central

    Bellido-Outeiriño, Francisco José; Quiles-Latorre, Francisco Javier; Moreno-Moreno, Carlos Diego; Flores-Arias, José María; Moreno-García, Isabel; Ortiz-López, Manuel

    2016-01-01

    Public lighting represents a large part of the energy consumption of towns and cities. Efficient management of public lighting can entail significant energy savings. This work presents a smart system for managing public lighting networks based on wireless communication and the DALI protocol. Wireless communication entails significant economic savings, as there is no need to install new wiring and visual impacts and damage to the facades of historical buildings in city centers are avoided. The DALI protocol uses bidirectional communication with the ballast, which allows its status to be controlled and monitored at all times. The novelty of this work is that it tackles all aspects related to the management of public lighting: a standard protocol, DALI, was selected to control the ballast, a wireless node based on the IEEE 802.15.4 standard with a DALI interface was designed, a network layer that considers the topology of the lighting network has been developed, and lastly, some user-friendly applications for the control and maintenance of the system by the technical crews of the different towns and cities have been developed. PMID:27128923

  15. 0.3THz wireless communication systems for space applications

    NASA Astrophysics Data System (ADS)

    Yuan, Weiwen; Wang, Hanqing; Li, Huiyuan; Zhang, Zhuo; Yang, Xiaojie; Shi, Weixun

    2015-11-01

    Contrary to the terahertz (THz) applications on the ground, the space applications in the atmosphere free environment do not suffer the atmosphere attenuation. In this study, a 0.3 THz wireless communication systems designed for potential space applications has been set up. It consists of transmitter and detector units based on Schottky diode mixers technology. The system performance is shown including the received signal levels and Eb/N0. For demonstration of THz communications, HD video signals have been transmitted over a distance of 14 m at the data rate of 1.5Gbps.

  16. Solar background effects in wireless optical communications

    NASA Astrophysics Data System (ADS)

    Sidorovich, Vladimir G.

    2002-12-01

    In free-space optical (FSO) communications, conditions may be met when laser links suffer from solar background radiation (SBR). There are four types of such conditions Direct sunlight hitting a photodetector Reflected sunlight (glints) Sunlight scattered by hydrometeors Sunlight scattered by surrounding objects (walls, etc.) Direct sunlight may cause total break of communications (link outage), and thus affect the link availability. However, experiments prove that the sunlight does not cause irreversible degradation of semiconductor photodetectors used in FSO systems. Estimations are made of the link outage periods duration for various types of SBR conditions, also other effects caused by SBR have been considered. Recommendations are presented for the link directivity optimization to avoid (or to minimize the probability of) communication interrupts caused by SBR. A nomographic chart has been developed to forecast periods of time when direct or scattered solar radiation may cause link outage. With this chart, a user in any point of the globe, knowing the link orientation (azimuth and elevation angles), can see when and for how long (if at all) may the link operation be affected by unfavorable SBR conditions, also in many cases it is possible to recommend insignificant modifications in the link orientation causing material improvement in FSO system performance.

  17. Next-generation optical wireless communications for data centers

    NASA Astrophysics Data System (ADS)

    Arnon, Shlomi

    2015-01-01

    Data centers collect and process information with a capacity that has been increasing from year to year at an almost exponential pace. Traditional fiber/cable data center network interconnections suffer from bandwidth overload, as well as flexibility and scalability issues. Therefore, a technology-shift from the fiber and cable to wireless has already been initiated in order to meet the required data-rate, flexibility and scalability demands for next-generation data center network interconnects. In addition, the shift to wireless reduces the volume allocated to the cabling/fiber and increases the cooling efficiency. Optical wireless communication (OWC), or free space optics (FSO), is one of the most effective wireless technologies that could be used in future data centers and could provide ultra-high capacity, very high cyber security and minimum latency, due to the low index of refraction of air in comparison to fiber technologies. In this paper we review the main concepts and configurations for next generation OWC for data centers. Two families of technologies are reviewed: the first technology regards interconnects between rack units in the same rack and the second technology regards the data center network that connects the server top of rack (TOR) to the switch. A comparison between different network technologies is presented.

  18. Silicon infrared diffuser for wireless communication.

    PubMed

    Massera, Ettore; Rea, Ilaria; Nasti, Ivana; Maddalena, Pasqualino; Di Francia, Girolamo

    2006-09-10

    We show what we believe to be a novel way to use silicon in infrared radio communication as a suitable material for the realization of optical diffusers in the range of 850-1600 nm. A crystalline silicon wafer is made porous by means of electrochemical etching. The porous silicon produced is optically characterized, and measurements report a high reflectance in the band of interest. We also study the angular distribution of diffused radiation by the porous silicon surface at different angles of incident radiation. Measurements show that radiation diffuses in a quasi-Lambertian manner, confirming the good performance of this material as an incident radiation diffuser. PMID:16926908

  19. Accurate measurement of RF exposure from emerging wireless communication systems

    NASA Astrophysics Data System (ADS)

    Letertre, Thierry; Monebhurrun, Vikass; Toffano, Zeno

    2013-04-01

    Isotropic broadband probes or spectrum analyzers (SAs) may be used for the measurement of rapidly varying electromagnetic fields generated by emerging wireless communication systems. In this paper this problematic is investigated by comparing the responses measured by two different isotropic broadband probes typically used to perform electric field (E-field) evaluations. The broadband probes are submitted to signals with variable duty cycles (DC) and crest factors (CF) either with or without Orthogonal Frequency Division Multiplexing (OFDM) modulation but with the same root-mean-square (RMS) power. The two probes do not provide accurate enough results for deterministic signals such as Worldwide Interoperability for Microwave Access (WIMAX) or Long Term Evolution (LTE) as well as for non-deterministic signals such as Wireless Fidelity (WiFi). The legacy measurement protocols should be adapted to cope for the emerging wireless communication technologies based on the OFDM modulation scheme. This is not easily achieved except when the statistics of the RF emission are well known. In this case the measurement errors are shown to be systematic and a correction factor or calibration can be applied to obtain a good approximation of the total RMS power.

  20. Non-line-of-sight underwater optical wireless communication network.

    PubMed

    Arnon, Shlomi; Kedar, Debbie

    2009-03-01

    The growing need for ocean observation systems has stimulated considerable interest within the research community in advancing the enabling technologies of underwater wireless communication and underwater sensor networks. Sensors and ad hoc sensor networks are the emerging tools for performing extensive data-gathering operations on land, and solutions in the subsea setting are being sought. Efficient communication from the sensors and within the network is critical, but the underwater environment is extremely challenging. Addressing the special features of underwater wireless communication in sensor networks, we propose a novel non-line-of-sight network concept in which the link is implemented by means of back-reflection of the propagating optic signal at the ocean-air interface and derive a mathematical model of the channel. Point-to-multipoint links can be achieved in an energy efficient manner and broadcast broadband communications, such as video transmissions, can be executed. We show achievable bit error rates as a function of sensor node separation and demonstrate the feasibility of this concept using state-of-the-art silicon photomultiplier detectors. PMID:19252651

  1. Artificial neural network for location estimation in wireless communication systems.

    PubMed

    Chen, Chien-Sheng

    2012-01-01

    In a wireless communication system, wireless location is the technique used to estimate the location of a mobile station (MS). To enhance the accuracy of MS location prediction, we propose a novel algorithm that utilizes time of arrival (TOA) measurements and the angle of arrival (AOA) information to locate MS when three base stations (BSs) are available. Artificial neural networks (ANN) are widely used techniques in various areas to overcome the problem of exclusive and nonlinear relationships. When the MS is heard by only three BSs, the proposed algorithm utilizes the intersections of three TOA circles (and the AOA line), based on various neural networks, to estimate the MS location in non-line-of-sight (NLOS) environments. Simulations were conducted to evaluate the performance of the algorithm for different NLOS error distributions. The numerical analysis and simulation results show that the proposed algorithms can obtain more precise location estimation under different NLOS environments. PMID:22736978

  2. Adaptive Precoded MIMO for LTE Wireless Communication

    NASA Astrophysics Data System (ADS)

    Nabilla, A. F.; Tiong, T. C.

    2015-04-01

    Long-Term Evolution (LTE) and Long Term Evolution-Advanced (ATE-A) have provided a major step forward in mobile communication capability. The objectives to be achieved are high peak data rates in high spectrum bandwidth and high spectral efficiencies. Technically, pre-coding means that multiple data streams are emitted from the transmit antenna with independent and appropriate weightings such that the link throughput is maximized at the receiver output thus increasing or equalizing the received signal to interference and noise (SINR) across the multiple receiver terminals. However, it is not reliable enough to fully utilize the information transfer rate to fit the condition of channel according to the bandwidth size. Thus, adaptive pre-coding is proposed. It applies pre-coding matrix indicator (PMI) channel state making it possible to change the pre-coding codebook accordingly thus improving the data rate higher than fixed pre-coding.

  3. Communication protocol in chassis detecting wireless transmission system based on WiFi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In chassis detecting wireless transmission system, the wireless network communication protocol plays a key role in the information exchange and synchronization between the host and chassis PDA. This paper presents a wireless network transmission protocol based on TCP/IP which makes the rules of info...

  4. Wireless communication capability of a reconfigurable plasma antenna

    SciTech Connect

    Kumar, Rajneesh; Bora, Dhiraj

    2011-03-15

    A 30 cm long plasma column is excited by a surface wave, which acts as a plasma antenna. Using plasma properties (pattern formation/striations in plasmas) single plasma antenna can be transformed into array, helical, and spiral plasma antenna. Experiments are carried out to study the power patterns, directivity, and half power beam width of such different plasma antennas. Moreover, field properties of plasma and copper antenna are studied. Further, wireless communication and jamming capability of plasma antenna are tested. Findings of this study suggest that directivity and communication range can be increased by converting single plasma antenna in to array/helical/spiral plasma antenna. Field frequencies of plasma antenna determine the communication and jamming of radio frequency waves. Therefore, this study invokes applications of pattern formation or striations of plasmas in plasma antenna technology.

  5. Communication Optimizations for a Wireless Distributed Prognostic Framework

    NASA Technical Reports Server (NTRS)

    Saha, Sankalita; Saha, Bhaskar; Goebel, Kai

    2009-01-01

    Distributed architecture for prognostics is an essential step in prognostic research in order to enable feasible real-time system health management. Communication overhead is an important design problem for such systems. In this paper we focus on communication issues faced in the distributed implementation of an important class of algorithms for prognostics - particle filters. In spite of being computation and memory intensive, particle filters lend well to distributed implementation except for one significant step - resampling. We propose new resampling scheme called parameterized resampling that attempts to reduce communication between collaborating nodes in a distributed wireless sensor network. Analysis and comparison with relevant resampling schemes is also presented. A battery health management system is used as a target application. A new resampling scheme for distributed implementation of particle filters has been discussed in this paper. Analysis and comparison of this new scheme with existing resampling schemes in the context for minimizing communication overhead have also been discussed. Our proposed new resampling scheme performs significantly better compared to other schemes by attempting to reduce both the communication message length as well as number total communication messages exchanged while not compromising prediction accuracy and precision. Future work will explore the effects of the new resampling scheme in the overall computational performance of the whole system as well as full implementation of the new schemes on the Sun SPOT devices. Exploring different network architectures for efficient communication is an importance future research direction as well.

  6. High Temperature Wireless Communication And Electronics For Harsh Environment Applications

    NASA Technical Reports Server (NTRS)

    Hunter, G. W.; Neudeck, P. G.; Beheim, G. M.; Ponchak, G. E.; Chen, L.-Y

    2007-01-01

    In order for future aerospace propulsion systems to meet the increasing requirements for decreased maintenance, improved capability, and increased safety, the inclusion of intelligence into the propulsion system design and operation becomes necessary. These propulsion systems will have to incorporate technology that will monitor propulsion component conditions, analyze the incoming data, and modify operating parameters to optimize propulsion system operations. This implies the development of sensors, actuators, and electronics, with associated packaging, that will be able to operate under the harsh environments present in an engine. However, given the harsh environments inherent in propulsion systems, the development of engine-compatible electronics and sensors is not straightforward. The ability of a sensor system to operate in a given environment often depends as much on the technologies supporting the sensor element as the element itself. If the supporting technology cannot handle the application, then no matter how good the sensor is itself, the sensor system will fail. An example is high temperature environments where supporting technologies are often not capable of operation in engine conditions. Further, for every sensor going into an engine environment, i.e., for every new piece of hardware that improves the in-situ intelligence of the components, communication wires almost always must follow. The communication wires may be within or between parts, or from the engine to the controller. As more hardware is added, more wires, weight, complexity, and potential for unreliability is also introduced. Thus, wireless communication combined with in-situ processing of data would significantly improve the ability to include sensors into high temperature systems and thus lead toward more intelligent engine systems. NASA Glenn Research Center (GRC) is presently leading the development of electronics, communication systems, and sensors capable of prolonged stable

  7. Communication techniques and challenges for wireless food quality monitoring.

    PubMed

    Jedermann, Reiner; Pötsch, Thomas; Lloyd, Chanaka

    2014-06-13

    Remote measurement of product core temperature is an important prerequisite to improve the cool chain of food products and reduce losses. This paper examines and shows possible solutions to technical challenges that still hinder practical applications of wireless sensor networks in the field of food transport supervision. The high signal attenuation by water-containing products limits the communication range to less than 0.5 m for the commonly used 2.4 GHz radio chips. By theoretical analysis of the dependency of signal attenuation on the operating frequency, we show that the signal attenuation can be largely reduced by the use of 433 MHz or 866 MHz devices, but forwarding of messages over multiple hops inside a sensor network is mostly unavoidable to guarantee full coverage of a packed container. Communication protocols have to provide compatibility with widely accepted standards for integration into the global Internet, which has been achieved by programming an implementation of the constrained application protocol for wireless sensor nodes and integrating into IPv6-based networks. The sensor's battery lifetime can be extended by optimizing communication protocols and by in-network pre-processing of the sensor data. The feasibility of remote freight supervision was demonstrated by our full-scale 'Intelligent Container' prototype. PMID:24797133

  8. Communication techniques and challenges for wireless food quality monitoring

    PubMed Central

    Jedermann, Reiner; Pötsch, Thomas; Lloyd, Chanaka

    2014-01-01

    Remote measurement of product core temperature is an important prerequisite to improve the cool chain of food products and reduce losses. This paper examines and shows possible solutions to technical challenges that still hinder practical applications of wireless sensor networks in the field of food transport supervision. The high signal attenuation by water-containing products limits the communication range to less than 0.5 m for the commonly used 2.4 GHz radio chips. By theoretical analysis of the dependency of signal attenuation on the operating frequency, we show that the signal attenuation can be largely reduced by the use of 433 MHz or 866 MHz devices, but forwarding of messages over multiple hops inside a sensor network is mostly unavoidable to guarantee full coverage of a packed container. Communication protocols have to provide compatibility with widely accepted standards for integration into the global Internet, which has been achieved by programming an implementation of the constrained application protocol for wireless sensor nodes and integrating into IPv6-based networks. The sensor's battery lifetime can be extended by optimizing communication protocols and by in-network pre-processing of the sensor data. The feasibility of remote freight supervision was demonstrated by our full-scale ‘Intelligent Container’ prototype. PMID:24797133

  9. 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

  10. Low Power/Low Noise Electronics Technologies for Wireless Communications

    NASA Astrophysics Data System (ADS)

    Itoh, Tatsuo

    2002-01-01

    We had previously written a Final Report for this award on August 1, 2001. At that time we provided ARO, as Appendix to Final Report, with three copies of the book 'RF Technologies for Low Power Wireless Communications'. Due to administrative reasons, we requested and were granted an extended contractual period to January 31, 2002. This period was used only to complete the last remaining technical activity that was carried out by the group of T. Itoh in the area of Active Integrated Antennas based on GaN transistor.

  11. Ultrafast all-optical technologies for bidirectional optical wireless communications.

    PubMed

    Jin, Xian; Hristovski, Blago A; Collier, Christopher M; Geoffroy-Gagnon, Simon; Born, Brandon; Holzman, Jonathan F

    2015-04-01

    In this Letter, a spherical retro-modulator architecture is introduced for operation as a bidirectional transceiver in passive optical wireless communication links. The architecture uses spherical retroreflection to enable retroreflection with broad directionality (2π steradians), and it uses all-optical beam interaction to enable modulation on ultrafast timescales (120 fs duration). The spherical retro-modulator is investigated from a theoretical standpoint and is fabricated for testing with three glasses, N-BK7, N-LASF9, and S-LAH79. It is found that the S-LAH79 structure provides the optimal refraction and nonlinearity for the desired retroreflection and modulation capabilities. PMID:25831390

  12. Communicable Disease Case Entry Using PDAs and Public Wireless Networks

    PubMed Central

    Lober, WB; Bliss, D; Dockrey, MR; Davidson, AJ; Karras, BT

    2003-01-01

    Concerns about detecting and responding to attacks with biowarfare agents have resulted in the development of deployable case reporting systems, e.g. RSVP1. We implement a proof of concept web-based information system to be used securely from personal digital assistants over public wireless networks, by public health field workers for routine and emergent case reporting. The system collects data for a local health jurisdiction, provides content- and event-based notification, and forwards case reports to the Colorado State communicable disease reporting system (CEDRS). We believe this demonstrates a useful integration of portable and web-based technologies with public health practice. PMID:14728422

  13. 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.

  14. 75 FR 8112 - In the Matter of Certain Mobile Telephones and Wireless Communication Devices Featuring Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... Cameras, and Components Thereof; Notice of Investigation AGENCY: U.S. International Trade Commission... communication devices featuring digital cameras, and components thereof by reason of infringement of certain... mobile telephones or wireless communication devices featuring digital cameras, or ] components...

  15. 77 FR 24738 - Certain Wireless Communication Devices and Systems, Components Thereof, and Products Containing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-25

    ... filed by Linex Technologies, Inc. of Palm Beach Gardens, Florida (``Linex''). 76 FR 33364 (June 8, 2011... COMMISSION Certain Wireless Communication Devices and Systems, Components Thereof, and Products Containing... States after importation of certain wireless communication devices and systems, components thereof,...

  16. 78 FR 13895 - Certain Wireless Communications Base Stations and Components Thereof; Institution of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-01

    ... COMMISSION Certain Wireless Communications Base Stations and Components Thereof; Institution of Investigation... wireless communications base stations and components thereof by reason of infringement of U.S. Patent No. 6..., the sale for importation, or the sale within the United States after importation of certain...

  17. 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...

  18. Technological Developments and Socio-Economic Issues of Wireless Mobile Communications.

    ERIC Educational Resources Information Center

    Beaubrun, Ronald; Pierre, Samuel

    2001-01-01

    Examines technological developments and the worldwide social-economic impacts of wireless mobile communications. Provides an overview of the technological developments of wireless mobile communications. Describes the evolution towards next-generation systems. Analyzes reasons for the growth rate of subscribers and the related social development.…

  19. Secure and Authenticated Data Communication in Wireless Sensor Networks.

    PubMed

    Alfandi, Omar; Bochem, Arne; Kellner, Ansgar; Göge, Christian; Hogrefe, Dieter

    2015-01-01

    Securing communications in wireless sensor networks is increasingly important as the diversity of applications increases. However, even today, it is equally important for the measures employed to be energy efficient. For this reason, this publication analyzes the suitability of various cryptographic primitives for use in WSNs according to various criteria and, finally, describes a modular, PKI-based framework for confidential, authenticated, secure communications in which most suitable primitives can be employed. Due to the limited capabilities of common WSN motes, criteria for the selection of primitives are security, power efficiency and memory requirements. The implementation of the framework and the singular components have been tested and benchmarked in our testbed of IRISmotes. PMID:26266413

  20. Secure and Authenticated Data Communication in Wireless Sensor Networks

    PubMed Central

    Alfandi, Omar; Bochem, Arne; Kellner, Ansgar; Göge, Christian; Hogrefe, Dieter

    2015-01-01

    Securing communications in wireless sensor networks is increasingly important as the diversity of applications increases. However, even today, it is equally important for the measures employed to be energy efficient. For this reason, this publication analyzes the suitability of various cryptographic primitives for use in WSNs according to various criteria and, finally, describes a modular, PKI-based framework for confidential, authenticated, secure communications in which most suitable primitives can be employed. Due to the limited capabilities of common WSN motes, criteria for the selection of primitives are security, power efficiency and memory requirements. The implementation of the framework and the singular components have been tested and benchmarked in our testbed of IRISmotes. PMID:26266413

  1. Underwater optical wireless communications: depth-dependent beam refraction.

    PubMed

    Johnson, Laura J; Green, Roger J; Leeson, Mark S

    2014-11-01

    Global refractive gradients in seawater cause pointing problems for optical wireless communications. A refractive index depth profile of the Pacific Ocean was calculated from measured salinity, temperature, and pressure, determining the end points of a refracted and nonrefracted 200 m communication link. Numerical ray tracing was used with a point source for angles between 10° and 80° and transmission wavelengths of 500-650 nm; the maximum end-point difference found was 0.23 m. A 500 nm laser with a 0.57° full-angle FOV was traced; the nonrefracted receiver location was outside the FOV for all links angled >15° to the vertical. However, most pointing issues underwater are unlikely to be significant with suitable FOV choice and natural scattering of the source. PMID:25402887

  2. Secure Many-to-One Communications in Wireless Sensor Networks

    PubMed Central

    Viejo, Alexandre; Domingo-Ferrer, Josep; Sebé, Francesc; Castellà-Roca, Jordi

    2009-01-01

    Wireless Sensor Networks (WSN) are formed by nodes with limited computational and power resources. WSNs are finding an increasing number of applications, both civilian and military, most of which require security for the sensed data being collected by the base station from remote sensor nodes. In addition, when many sensor nodes transmit to the base station, the implosion problem arises. Providing security measures and implosion-resistance in a resource-limited environment is a real challenge. This article reviews the aggregation strategies proposed in the literature to handle the bandwidth and security problems related to many-to-one transmission in WSNs. Recent contributions to secure lossless many-to-one communication developed by the authors in the context of several Spanish-funded projects are surveyed. Ongoing work on the secure lossy many-to-one communication is also sketched. PMID:22346700

  3. Error resiliency of distributed video coding in wireless video communication

    NASA Astrophysics Data System (ADS)

    Ye, Shuiming; Ouaret, Mourad; Dufaux, Frederic; Ansorge, Michael; Ebrahimi, Touradj

    2008-08-01

    Distributed Video Coding (DVC) is a new paradigm in video coding, based on the Slepian-Wolf and Wyner-Ziv theorems. DVC offers a number of potential advantages: flexible partitioning of the complexity between the encoder and decoder, robustness to channel errors due to intrinsic joint source-channel coding, codec independent scalability, and multi-view coding without communications between the cameras. In this paper, we evaluate the performance of DVC in an error-prone wireless communication environment. We also present a hybrid spatial and temporal error concealment approach for DVC. Finally, we perform a comparison with a state-of-the-art AVC/H.264 video coding scheme in the presence of transmission errors.

  4. Wireless communication in clinical environments with unique needs.

    PubMed

    Wilson, Rosemary; Duhn, Lenora; Gonzalez, Paola; Hall, Susan; Chan, Yolande E; VanDenKerkhof, Elizabeth G

    2014-01-01

    Wireless technology in healthcare has been associated with communication-related improvements in workflow; however, there are barriers to adoption. This study examined predictors of use of wireless communication devices (WCDs) in environments with unique needs (i.e., intensive care unit [ICU]). Nurses were recruited in the ICU to complete a paper questionnaire to assess their willingness to use WCDs. The Theory of Planned Behaviour was used to assess attitudes, subjective norms, perceived control, and behavioral intent. Responses included Likert scale scores and open-ended questions. Data were collected before and following the implementation of WCDs in ICU. The combined effects of attitudes, perceived control and subjective norms on behavioral intent were tested using the general linear model. The narrative data were analyzed using a thematic analysis approach. Attitudes and subjective norms were predictors of behavioral intent to use WCDs preimplementation but not postimplementation. Differences in the factors affecting intent to use WCDs between the ICU and the surgical unit may be related to the unique nature of the critical care environment, and to the lack of a comprehensive preimplementation strategy. A study examining predictors of use on a general inpatient unit where a comprehensive implementation strategy was not employed would provide insight into whether these findings are related to the implementation strategy or the unique nature of the critical care environment. Improved understanding of the function and application of innovative technology at the point of care, and attention to the process of implementation may improve adoption of this potentially beneficial device. PMID:24033884

  5. Structured-light-assisted wireless digital optical communications

    NASA Astrophysics Data System (ADS)

    Long, Yunfei; Wang, Shuaijun; Wu, Wei; Yang, Xiaomin; Jeon, Gwanggil; Liu, Kai

    2015-11-01

    Camera-projector-pair-based digital optical communications are attractive for safe and flexible usages, while the state-of-the-art systems suffer from various disadvantages or distortions of communication channels, including the irregularity and the non-uniform albedo of projection surfaces, the radial distortion of optical lenses, etc. In this paper, we present a novel method for digital optical communications. Assisted by structured light illumination, we overcome those disadvantages and accurately derive the models of the communication channels. First, by deriving accurate model-free coordinates maps for the camera-projector pair, we overcome the issues caused by the irregularity of projection surfaces and the radial distortion of optical lenses. Second, by normalizing received digital optical signals with calibrated system parameters, we overcome the issue arising from the non-uniform albedo of projection surfaces. Thus, with the models and all pixel-wise operations, we finally achieve robust and real-time wireless digital optical communications. Experimental results verify the validity of the proposed method.

  6. The Effect on Wireless Sensor Communication When Deployed in Biomass

    PubMed Central

    Larsen, Jakob Juul; Green, Ole; Nadimi, Esmaeil S.; Toftegaard, Thomas Skjødeberg

    2011-01-01

    Wireless sensor networks (WSN) have been studied in a variety of scenarios over recent years, but work has almost exclusively been done using air as the transmission media. In this article some of the challenges of deploying a WSN in a heterogeneous biomass, in this case silage, is handled. The dielectric constant of silage is measured using an open-ended coaxial probe. Results were successfully obtained in the frequency range from 400 MHz to 4 GHz, but large variations suggested that a larger probe should be used for more stable results. Furthermore, the detuning of helix and loop antennas and the transmission loss of the two types of antennas embedded in silage was measured. It was found that the loop antenna suffered less from detuning but was worse when transmitting. Lastly, it is suggested that taking the dielectric properties of silage into account during hardware development could result in much better achievable communication range. PMID:22164076

  7. Simulation of Wearable Antennas for Body Centric Wireless Communication

    NASA Astrophysics Data System (ADS)

    Cousin, Richard; Rütschlin, Marc; Wittig, Tilmann; Bhattacharya, Arnab

    2015-11-01

    The performance of a body area network (BAN) is strongly dependent on several parameters which make wireless communication quite challenging. For instance, the performance of the antenna itself could be affected by its geometric deformation when the structure is directly integrated into clothes. Operation of the antenna close to the human body necessitates adjusting its design for the intended applications whereas the maximum SAR value estimated in such conditions has to respect the standards. In this context, simulation tools that can take into account specific biological models offer a range of possibilities for investigating and optimizing the performance of BAN devices. Two different applications are presented here: the case of an RFID tag operating at 870 MHz, and a UWB antenna working in a frequency range between 3 and 6 GHz. The simulation tools developed by CST are used in this context to optimize the implementation of BAN devices shown in this paper.

  8. Performance analysis of coherent wireless optical communications with atmospheric turbulence.

    PubMed

    Niu, Mingbo; Song, Xuegui; Cheng, Julian; Holzman, Jonathan F

    2012-03-12

    Coherent wireless optical communication systems with heterodyne detection are analyzed for binary phase-shift keying (BPSK), differential PSK (DPSK), and M-ary PSK over Gamma-Gamma turbulence channels. Closed-form error rate expressions are derived using a series expansion approach. It is shown that, in the special case of K-distributed turbulence channel, the DPSK incurs a 3 dB signal-to-noise ratio (SNR) penalty compared to BPSK in the large SNR regime. The outage probability is also obtained, and a detailed outage truncation error analysis is presented and used to assess the accuracy in system performance estimation. It is shown that our series error rate expressions are simple to use and highly accurate for practical system performance estimation. PMID:22418534

  9. A Low Cost Traveling Wave Tube for Wireless Communications

    NASA Technical Reports Server (NTRS)

    Vancil, Bernard Kenneth; Wintucky, Edwin G.; Williams, W. D. (Technical Monitor)

    2002-01-01

    Demand for high data rate wireless communications is pushing up amplifier power, bandwidth and frequency requirements. Some systems are using vacuum electron devices again because solid-state power amplifiers are not able to efficiently meet the new requirements. The traveling wave tube is the VED of choice because of its excellent broadband capability as well as high power efficiency and frequency. But TWTs are very expensive on a per watt basis below about 200 watts of output power. We propose a new traveling wave tube that utilizes cathode ray tube construction technology and electrostatic focusing. We believe the tube can be built in quantity for under $1,000 each. We discuss several traveling wave tube slow wave circuits that lend themselves to the new construction. We will present modeling results and data on prototype devices.

  10. 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.

  11. Wireless Communication of Intraoral Devices and Its Optimal Frequency Selection

    PubMed Central

    Park, Hangue; Ghovanloo, Maysam

    2015-01-01

    This paper explores communication methods and frequencies for wireless intraoral electronic devices, by using an intraoral tongue drive system (iTDS) as a practical example. Because intraoral devices do not meet the operating conditions of the body channel communication, we chose radio frequency communication. We evaluated and compared three frequencies in industrial, scientific, and medical bands (27 MHz, 433.9 MHz, and 2.48 GHz) in terms of their data link performance based on path loss and radiation patterns over horizontal and vertical planes. To do so, we dynamically minimize the impedance mismatch caused by the varying oral environment by applying the adaptive impedance matching technique to 433.9 MHz and 2.48 GHz bands. Experimental results showed that 27 MHz has the smallest path loss in the near-field up to 39 cm separation between transmitter and receiver antennas. However, 433.9 MHz shows the best performance beyond 39 cm and offers a maximum operating distance of 123 cm with 0 dBm transmitter output power. These distances were obtained by a bit error rate test and verified by a link budget analysis and full functionality test of the iTDS with computer access. PMID:26236039

  12. 78 FR 33145 - Meeting: RTCA Special Committee 223, Airport Surface Wireless Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-03

    ... Federal Aviation Administration Meeting: RTCA Special Committee 223, Airport Surface Wireless...: Meeting Notice of RTCA Special Committee 223, Airport Surface Wireless Communications. SUMMARY: The FAA is issuing this notice to advise the public of the meeting of the RTCA Special Committee 223, Airport...

  13. Challenge Study: A Project-Based Learning on a Wireless Communication System at Technical High School

    ERIC Educational Resources Information Center

    Terasawa, Ikuo

    2016-01-01

    The challenge study is a project based learning curriculum at Technical High School aimed at the construction of a wireless communication system. The first period was engineering issues in the construction of an artificial satellite and the second period was a positional locating system based on the general purpose wire-less device--ZigBee device.…

  14. Wireless sensor systems for sense/decide/act/communicate.

    SciTech Connect

    Berry, Nina M.; Cushner, Adam; Baker, James A.; Davis, Jesse Zehring; Stark, Douglas P.; Ko, Teresa H.; Kyker, Ronald D.; Stinnett, Regan White; Pate, Ronald C.; Van Dyke, Colin; Kyckelhahn, Brian

    2003-12-01

    After 9/11, the United States (U.S.) was suddenly pushed into challenging situations they could no longer ignore as simple spectators. The War on Terrorism (WoT) was suddenly ignited and no one knows when this war will end. While the government is exploring many existing and potential technologies, the area of wireless Sensor networks (WSN) has emerged as a foundation for establish future national security. Unlike other technologies, WSN could provide virtual presence capabilities needed for precision awareness and response in military, intelligence, and homeland security applications. The Advance Concept Group (ACG) vision of Sense/Decide/Act/Communicate (SDAC) sensor system is an instantiation of the WSN concept that takes a 'systems of systems' view. Each sensing nodes will exhibit the ability to: Sense the environment around them, Decide as a collective what the situation of their environment is, Act in an intelligent and coordinated manner in response to this situational determination, and Communicate their actions amongst each other and to a human command. This LDRD report provides a review of the research and development done to bring the SDAC vision closer to reality.

  15. Clustering and Beamforming for Efficient Communication in Wireless Sensor Networks.

    PubMed

    Porcel-Rodríguez, Francisco; Valenzuela-Valdés, Juan; Padilla, Pablo; Luna-Valero, Francisco; Luque-Baena, Rafael; López-Gordo, Miguel Ángel

    2016-01-01

    Energy efficiency is a critical issue for wireless sensor networks (WSNs) as sensor nodes have limited power availability. In order to address this issue, this paper tries to maximize the power efficiency in WSNs by means of the evaluation of WSN node networks and their performance when both clustering and antenna beamforming techniques are applied. In this work, four different scenarios are defined, each one considering different numbers of sensors: 50, 20, 10, five, and two nodes per scenario, and each scenario is randomly generated thirty times in order to statistically validate the results. For each experiment, two different target directions for transmission are taken into consideration in the optimization process (φ = 0° and θ = 45°; φ = 45°, and θ = 45°). Each scenario is evaluated for two different types of antennas, an ideal isotropic antenna and a conventional dipole one. In this set of experiments two types of WSN are evaluated: in the first one, all of the sensors have the same amount of power for communications purposes; in the second one, each sensor has a different amount of power for its communications purposes. The analyzed cases in this document are focused on 2D surface and 3D space for the node location. To the authors' knowledge, this is the first time that beamforming and clustering are simultaneously applied to increase the network lifetime in WSNs. PMID:27556463

  16. Synchronization for wireless multi-radar covert communication networks

    NASA Astrophysics Data System (ADS)

    Surender, Shrawan C.; Narayanan, Ram M.

    2007-04-01

    The motivation for our current work is the need for a covert wireless communication network between multi-site radars. Such radars form an effective network-centric architecture that has intrinsic properties such as LPI, LPD, and good data dissemination capabilities. Our continuing work indicates that a notched UWB noise signal within which OFDM data symbols are embedded can be used as a secure communication channel between individual noise radars. The receiver performance in such systems depends heavily on the timing of the DFT window for detecting the message symbols concealed within the noise-OFDM waveform. Performance is therefore severely limited due to the effects of timing and frequency offsets on the noise-data signal. These synchronization errors bring unwanted noise into this window in the form of ICI, ISI, etc. In this paper, we show that most of the techniques developed for a simple OFDM system do not suit the covert noise-OFDM system requirements. We further propose a packet/frame detection and timing estimation technique for the noise-data signal used between the random noise radars. This technique is unique as it is applied to OFDM symbols embedded in UWB noise. With no preprocessing required in the transmitter and no knowledge about the source noise signal, the correlation properties of band-limited white noise are exploited to achieve synchronization.

  17. Teaching the Fundamentals of Cell Phones and Wireless Communications

    NASA Astrophysics Data System (ADS)

    Davids, Mark; Forrest, Rick; Pata, Don

    2010-04-01

    Wireless communications are ubiquitous. Students and teachers use iPhones®, BlackBerrys®, and other smart phones at home and at work. More than 275 million Americans had cell phones in June of 2009 and expanded access to broadband is predicted this year.2 Despite the plethora of users, most students and teachers do not understand "how they work." Over the past several years, three high school teachers have collaborated with engineers at Cingular, Motorola, and the University of Michigan to explore the underlying science and design a three-week, student-centered unit with a constructivist pedagogy consistent with the "Modeling in Physics" philosophy.3 This unique pilot program reinforces traditional physics topics including vibrations and waves, sound, light, electricity and magnetism, and also introduces key concepts in communications and information theory. This article will describe the motivation for our work, outline a few key concepts with the corresponding student activities, and provide a summary of the program that has been developed to engage and inspire the next generation of scientists, engineers, and citizens.

  18. Breakdown Behavior of a Wireless Communication Network Under UWB Impact

    NASA Astrophysics Data System (ADS)

    Rohe, M.; Koch, M.

    Systems with high priority to safety and reliability such as monitoring systems on airports have to work properly. Fast information transmission, continuous access to databases, as well as the management of air traffic are most important for effective and safe operation. Sources of Intentional Electromagnetic Interference can be manufactured relatively easy using commercially available components by civilian persons with relevant expertise and can be used for sabotage or blackmail purposes. For analyzing the weak points of a system existing on airports, it is necessary to reproduce its setup. In this investigation a UHF transmitter of a wireless communication device is developed and its breakdown behavior to unipolar fast rise pulses (UWB) is determined. A breakdown is a non-permanent damage, but includes a type of upset, that requires manual reset or at least stops communications for some period of time. The transmitter consists of three main components connected by data cables: power supply, microcontroller, and loop antenna. The immunity tests are accomplished as a function of the electromagnetic field direction to the device using an open TEM waveguide.

  19. 77 FR 65580 - Certain Wireless Communication Devices, Portable Music and Data Processing Devices, Computers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-29

    ..., Bermuda; and Motorola Mobility International of Hamilton, Bermuda (collectively, (``Motorola''). 77 FR... From the Federal Register Online via the Government Publishing Office ] INTERNATIONAL TRADE COMMISSION Certain Wireless Communication Devices, Portable Music and Data Processing Devices, Computers,...

  20. 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.

  1. Energy Efficiency Maximization of Practical Wireless Communication Systems

    NASA Astrophysics Data System (ADS)

    Eraslan, Eren

    Energy consumption of the modern wireless communication systems is rapidly growing due to the ever-increasing data demand and the advanced solutions employed in order to address this demand, such as multiple-input multiple-output (MIMO) and orthogonal frequency division multiplexing (OFDM) techniques. These MIMO systems are power hungry, however, they are capable of changing the transmission parameters, such as number of spatial streams, number of transmitter/receiver antennas, modulation, code rate, and transmit power. They can thus choose the best mode out of possibly thousands of modes in order to optimize an objective function. This problem is referred to as the link adaptation problem. In this work, we focus on the link adaptation for energy efficiency maximization problem, which is defined as choosing the optimal transmission mode to maximize the number of successfully transmitted bits per unit energy consumed by the link. We model the energy consumption and throughput performances of a MIMO-OFDM link and develop a practical link adaptation protocol, which senses the channel conditions and changes its transmission mode in real-time. It turns out that the brute force search, which is usually assumed in previous works, is prohibitively complex, especially when there are large numbers of transmit power levels to choose from. We analyze the relationship between the energy efficiency and transmit power, and prove that energy efficiency of a link is a single-peaked quasiconcave function of transmit power. This leads us to develop a low-complexity algorithm that finds a near-optimal transmit power and take this dimension out of the search space. We further prune the search space by analyzing the singular value decomposition of the channel and excluding the modes that use higher number of spatial streams than the channel can support. These algorithms and our novel formulations provide simpler computations and limit the search space into a much smaller set; hence

  2. Wireless communication and spectrum sharing for public safety in the United States.

    PubMed

    Kapucu, Naim; Haupt, Brittany; Yuksel, Murat

    2016-01-01

    With the vast number of fragmented, independent public safety wireless communication systems, the United States is encountering major challenges with enhancing interoperability and effectively managing costs while sharing limited availability of critical spectrum. The traditional hierarchical approach of emergency management does not always allow for needed flexibility and is not a mandate. A national system would reduce equipment needs, increase effectiveness, and enrich quality and coordination of response; however, it is dependent on integrating the commercial market. This article discusses components of an ideal national wireless public safety system consists along with key policies in regulating wireless communication and spectrum sharing for public safety and challenges for implementation. PMID:27438959

  3. CMOS mm-wave transceivers for Gbps wireless communication

    NASA Astrophysics Data System (ADS)

    Baoyong, Chi; Zheng, Song; Lixue, Kuang; Haikun, Jia; Xiangyu, Meng; Zhihua, Wang

    2016-07-01

    The challenges in the design of CMOS millimeter-wave (mm-wave) transceiver for Gbps wireless communication are discussed. To support the Gbps data rate, the link bandwidth of the receiver/transmitter must be wide enough, which puts a lot of pressure on the mm-wave front-end as well as on the baseband circuit. This paper discusses the effects of the limited link bandwidth on the transceiver system performance and overviews the bandwidth expansion techniques for mm-wave amplifiers and IF programmable gain amplifier. Furthermore, dual-mode power amplifier (PA) and self-healing technique are introduced to improve the PA's average efficiency and to deal with the process, voltage, and temperature variation issue, respectively. Several fully-integrated CMOS mm-wave transceivers are also presented to give a short overview on the state-of-the-art mm-wave transceivers. Project supported in part by the National Natural Science Foundation of China (No. 61331003).

  4. Chain-based communication in cylindrical underwater wireless sensor networks.

    PubMed

    Javaid, Nadeem; Jafri, Mohsin Raza; Khan, Zahoor Ali; Alrajeh, Nabil; Imran, Muhammad; Vasilakos, Athanasios

    2015-01-01

    Appropriate network design is very significant for Underwater Wireless Sensor Networks (UWSNs). Application-oriented UWSNs are planned to achieve certain objectives. Therefore, there is always a demand for efficient data routing schemes, which can fulfill certain requirements of application-oriented UWSNs. These networks can be of any shape, i.e., rectangular, cylindrical or square. In this paper, we propose chain-based routing schemes for application-oriented cylindrical networks and also formulate mathematical models to find a global optimum path for data transmission. In the first scheme, we devise four interconnected chains of sensor nodes to perform data communication. In the second scheme, we propose routing scheme in which two chains of sensor nodes are interconnected, whereas in third scheme single-chain based routing is done in cylindrical networks. After finding local optimum paths in separate chains, we find global optimum paths through their interconnection. Moreover, we develop a computational model for the analysis of end-to-end delay. We compare the performance of the above three proposed schemes with that of Power Efficient Gathering System in Sensor Information Systems (PEGASIS) and Congestion adjusted PEGASIS (C-PEGASIS). Simulation results show that our proposed 4-chain based scheme performs better than the other selected schemes in terms of network lifetime, end-to-end delay, path loss, transmission loss, and packet sending rate. PMID:25658394

  5. Harvest-Then-Cooperate: Wireless-Powered Cooperative Communications

    NASA Astrophysics Data System (ADS)

    Chen, He; Li, Yonghui; Luiz Rebelatto, Joao; Uchoa-Filho, Bartolomeu F.; Vucetic, Branka

    2015-04-01

    In this paper, we consider a wireless-powered cooperative communication network consisting of one hybrid access-point (AP), one source, and one relay. In contrast to conventional cooperative networks, the source and relay in the considered network have no embedded energy supply. They need to rely on the energy harvested from the signals broadcasted by the AP for their cooperative information transmission. Based on this three-node reference model, we propose a harvest-then-cooperate (HTC) protocol, in which the source and relay harvest energy from the AP in the downlink and work cooperatively in the uplink for the source's information transmission. Considering a delay-limited transmission mode, the approximate closed-form expression for the average throughput of the proposed protocol is derived over Rayleigh fading channels. Subsequently, this analysis is extended to the multi-relay scenario, where the approximate throughput of the HTC protocol with two popular relay selection schemes is derived. The asymptotic analyses for the throughput performance of the considered schemes at high signal-to-noise radio are also provided. All theoretical results are validated by numerical simulations. The impacts of the system parameters, such as time allocation, relay number, and relay position, on the throughput performance are extensively investigated.

  6. Chain-Based Communication in Cylindrical Underwater Wireless Sensor Networks

    PubMed Central

    Javaid, Nadeem; Jafri, Mohsin Raza; Khan, Zahoor Ali; Alrajeh, Nabil; Imran, Muhammad; Vasilakos, Athanasios

    2015-01-01

    Appropriate network design is very significant for Underwater Wireless Sensor Networks (UWSNs). Application-oriented UWSNs are planned to achieve certain objectives. Therefore, there is always a demand for efficient data routing schemes, which can fulfill certain requirements of application-oriented UWSNs. These networks can be of any shape, i.e., rectangular, cylindrical or square. In this paper, we propose chain-based routing schemes for application-oriented cylindrical networks and also formulate mathematical models to find a global optimum path for data transmission. In the first scheme, we devise four interconnected chains of sensor nodes to perform data communication. In the second scheme, we propose routing scheme in which two chains of sensor nodes are interconnected, whereas in third scheme single-chain based routing is done in cylindrical networks. After finding local optimum paths in separate chains, we find global optimum paths through their interconnection. Moreover, we develop a computational model for the analysis of end-to-end delay. We compare the performance of the above three proposed schemes with that of Power Efficient Gathering System in Sensor Information Systems (PEGASIS) and Congestion adjusted PEGASIS (C-PEGASIS). Simulation results show that our proposed 4-chain based scheme performs better than the other selected schemes in terms of network lifetime, end-to-end delay, path loss, transmission loss, and packet sending rate. PMID:25658394

  7. A Wireless Communications Laboratory on Cellular Network Planning

    ERIC Educational Resources Information Center

    Dawy, Z.; Husseini, A.; Yaacoub, E.; Al-Kanj, L.

    2010-01-01

    The field of radio network planning and optimization (RNPO) is central for wireless cellular network design, deployment, and enhancement. Wireless cellular operators invest huge sums of capital on deploying, launching, and maintaining their networks in order to ensure competitive performance and high user satisfaction. This work presents a lab…

  8. Optical wireless communication in sensor networks: data harvesting for disaster recovery operations

    NASA Astrophysics Data System (ADS)

    Arnon, Shlomi; Kedar, Debbie

    2007-09-01

    Networks of sensors are an emerging technology for real-time data gathering in applications such as pollution monitoring, home security, surveillance, industrial control, etc. Many miniature nodes with sensing, computing and wireless communication capabilities are randomly deployed in an area or volume to be probed. One of the possible communication modalities for sensor networks is optical wireless communication (OWC). Initially, the sensor population must be mapped prior to interrogation by the base station and data communication from the sensor node. In this paper we review some theoretical and experimental work in this area and underline some of the challenges and possible solutions. The specific scenario of wireless sensor networks in a disaster recovery operation is modeled.

  9. Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications.

    PubMed

    Huang, Xianjun; Leng, Ting; Zhu, Mengjian; Zhang, Xiao; Chen, JiaCing; Chang, KuoHsin; Aqeeli, Mohammed; Geim, Andre K; Novoselov, Kostya S; Hu, Zhirun

    2015-01-01

    In this paper, we report highly conductive, highly flexible, light weight and low cost printed graphene for wireless wearable communications applications. As a proof of concept, printed graphene enabled transmission lines and antennas on paper substrates were designed, fabricated and characterized. To explore its potentials in wearable communications applications, mechanically flexible transmission lines and antennas under various bended cases were experimentally studied. The measurement results demonstrate that the printed graphene can be used for RF signal transmitting, radiating and receiving, which represents some of the essential functionalities of RF signal processing in wireless wearable communications systems. Furthermore, the printed graphene can be processed at low temperature so that it is compatible with heat-sensitive flexible materials like papers and textiles. This work brings a step closer to the prospect to implement graphene enabled low cost and environmentally friendly wireless wearable communications systems in the near future. PMID:26673395

  10. Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications

    NASA Astrophysics Data System (ADS)

    Huang, Xianjun; Leng, Ting; Zhu, Mengjian; Zhang, Xiao; Chen, Jiacing; Chang, Kuohsin; Aqeeli, Mohammed; Geim, Andre K.; Novoselov, Kostya S.; Hu, Zhirun

    2015-12-01

    In this paper, we report highly conductive, highly flexible, light weight and low cost printed graphene for wireless wearable communications applications. As a proof of concept, printed graphene enabled transmission lines and antennas on paper substrates were designed, fabricated and characterized. To explore its potentials in wearable communications applications, mechanically flexible transmission lines and antennas under various bended cases were experimentally studied. The measurement results demonstrate that the printed graphene can be used for RF signal transmitting, radiating and receiving, which represents some of the essential functionalities of RF signal processing in wireless wearable communications systems. Furthermore, the printed graphene can be processed at low temperature so that it is compatible with heat-sensitive flexible materials like papers and textiles. This work brings a step closer to the prospect to implement graphene enabled low cost and environmentally friendly wireless wearable communications systems in the near future.

  11. Highly Flexible and Conductive Printed Graphene for Wireless Wearable Communications Applications

    PubMed Central

    Huang, Xianjun; Leng, Ting; Zhu, Mengjian; Zhang, Xiao; Chen, JiaCing; Chang, KuoHsin; Aqeeli, Mohammed; Geim, Andre K.; Novoselov, Kostya S.; Hu, Zhirun

    2015-01-01

    In this paper, we report highly conductive, highly flexible, light weight and low cost printed graphene for wireless wearable communications applications. As a proof of concept, printed graphene enabled transmission lines and antennas on paper substrates were designed, fabricated and characterized. To explore its potentials in wearable communications applications, mechanically flexible transmission lines and antennas under various bended cases were experimentally studied. The measurement results demonstrate that the printed graphene can be used for RF signal transmitting, radiating and receiving, which represents some of the essential functionalities of RF signal processing in wireless wearable communications systems. Furthermore, the printed graphene can be processed at low temperature so that it is compatible with heat-sensitive flexible materials like papers and textiles. This work brings a step closer to the prospect to implement graphene enabled low cost and environmentally friendly wireless wearable communications systems in the near future. PMID:26673395

  12. Robust Networking Architecture and Secure Communication Scheme for Heterogeneous Wireless Sensor Networks

    ERIC Educational Resources Information Center

    McNeal, McKenzie, III.

    2012-01-01

    Current networking architectures and communication protocols used for Wireless Sensor Networks (WSNs) have been designed to be energy efficient, low latency, and long network lifetime. One major issue that must be addressed is the security in data communication. Due to the limited capabilities of low cost and small sized sensor nodes, designing…

  13. Airborne Wireless Optical Communication System in Low Altitude Using an Unmanned Aerial Vehicle and LEDs

    NASA Astrophysics Data System (ADS)

    Kong, Meiwei; Tong, Zheng; Yu, Xiangyu; Song, Yuhang; Lin, Aobo; Xu, Jing

    2016-02-01

    In this paper, we demonstrate the feasibility of airborne wireless optical communication system using an unmanned aerial vehicle and LEDs. Monte Carlo simulation method is used to evaluate the performance of the communication channel. Considering OOK modulation, we illustrate how the BER performance is affected by the link distance, the divergence angel and the deflection angel of the light source.

  14. Peer Coaching with Interactive Wireless Technology between Student Teachers: Satisfaction with Role and Communication

    ERIC Educational Resources Information Center

    Fry, Joan Marian; Hin, Michael Koh Teik

    2006-01-01

    In technology-savvy Singapore, wireless communication devices were used over four weekly lessons to facilitate communication between pairs of student teachers (STs). In the naturalistic setting of a neighbourhood primary school, one ST used the technology to coach the other who was engaged in teaching. (Both were familiar with the lesson plan and…

  15. DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS FOR INTELLIGENT COMPLETIONS APPLICATIONS

    SciTech Connect

    Paul Tubel

    2005-05-08

    The development work during this quarter was focused in the test of the wireless gauge in a well. The tool was sent to Halliburton for a test. The company indicated that the test well was not available for 4 months and the company was not able to schedule a test of the wireless gauge in its test well. The tool was returned to Tubel Tech's facility in The Woodlands. Tubel Tech is looking for a new test well to deploy the wireless gauge to complete the requirements for the DOE.

  16. Installation of secure, always available wireless LAN systems as a component of the hospital communication infrastructure.

    PubMed

    Hanada, Eisuke; Kudou, Takato; Tsumoto, Shusaku

    2013-06-01

    Wireless technologies as part of the data communication infrastructure of modern hospitals are being rapidly introduced. Even though there are concerns about problems associated with wireless communication security, the demand is remarkably large. In addition, insuring that the network is always available is important. Herein, we discuss security countermeasures and points to insure availability that must be taken to insure safe hospital/business use of wireless LAN systems, referring to the procedures introduced at Shimane University Hospital. Security countermeasures differ according to their purpose, such as for preventing illegal use or insuring availability, both of which are discussed. It is our hope that this information will assist others in their efforts to insure safe implementation of wireless LAN systems, especially in hospitals where they have the potential to greatly improve information sharing and patient safety. PMID:23519703

  17. A reinforcement learning trained fuzzy neural network controller for maintaining wireless communication connections in multi-robot systems

    NASA Astrophysics Data System (ADS)

    Zhong, Xu; Zhou, Yu

    2014-05-01

    This paper presents a decentralized multi-robot motion control strategy to facilitate a multi-robot system, comprised of collaborative mobile robots coordinated through wireless communications, to form and maintain desired wireless communication coverage in a realistic environment with unstable wireless signaling condition. A fuzzy neural network controller is proposed for each robot to maintain the wireless link quality with its neighbors. The controller is trained through reinforcement learning to establish the relationship between the wireless link quality and robot motion decision, via consecutive interactions between the controller and environment. The tuned fuzzy neural network controller is applied to a multi-robot deployment process to form and maintain desired wireless communication coverage. The effectiveness of the proposed control scheme is verified through simulations under different wireless signal propagation conditions.

  18. Downhole Power Generation and Wireless Communications for Intelligent Completions Applications

    SciTech Connect

    Paul Tubel

    2005-11-07

    Tubel Tech has been working with the DoE Rocky Mountain test center to create a CRADA which will allow Tubel Tech to test its wireless gauge in a well at the test center. The CRADA agreement should be completed by the next quarter and Tubel Tech expects to perform the final test on this project during the next quarter as well. The wireless gauge has not been modified or upgraded during this report period.

  19. The Use of Wireless E-Mail to Improve Healthcare Team Communication

    PubMed Central

    O'Connor, Chris; Friedrich, Jan O.; Scales, Damon C.; Adhikari, Neill K.J.

    2009-01-01

    Objective To assess the impact of using wireless e-mail for clinical communication in an intensive care unit (ICU). Design The authors implemented push wireless e-mail over a GSM cellular network in a 26-bed ICU during a 6-month study period. Daytime ICU staff (intensivists, nurses, respiratory therapists, pharmacists, clerical staff, and ICU leadership) used handheld devices (BlackBerry, Research in Motion, Waterloo, ON) without dedicated training. The authors recorded e-mail volume and used standard methods to develop a self-administered survey of ICU staff to measure wireless e-mail impact. Measurements The survey assessed perceived impact of wireless e-mail on communication, team relationships, staff satisfaction and patient care. Answers were recorded on a 7-point Likert scale; favorable responses were categorized as Likert responses 5, 6, and 7. Results Staff sent 5.2 (1.9) and received 8.9 (2.1) messages (mean [SD]) per day during 5 months of the 6-month study period; usage decreased after study completion. Most (106/125 [85%]) staff completed the questionnaire. The majority reported that wireless e-mail improved speed (92%) and reliability (92%) of communication, improved coordination of ICU team members (88%), reduced staff frustration (75%), and resulted in faster (90%) and safer (75%) patient care; Likert responses were significantly different from neutral (p < 0.001 for all). Staff infrequently (18%) reported negative effects on communication. There were no reports of radiofrequency interference with medical devices. Conclusions Interdisciplinary ICU staff perceived wireless e-mail to improve communication, team relationships, staff satisfaction, and patient care. Further research should address the impact of wireless e-mail on efficiency and timeliness of staff workflow and clinical outcomes. PMID:19567803

  20. DEVELOPMENT OF A COMPREHENSIVE WIRELESS COMMUNICATIONS SYSTEM FOR THE UNDERGROUND MINING INDUSTRY

    SciTech Connect

    Zvi H. Meiksin

    2001-04-01

    Progress continued along both subsystems towards an integrated comprehensive wireless communications system for the underground mining industry. Designing an automated continuous self-tuning mechanism that optimizes signal transmission intensity for a given power input enhanced through-the-earth communications. In-mine communications was enhanced through the design of a circuit that eliminates multi-antenna interference, cleaning-up the received signal.

  1. The design, test, and application of the front end in 0.3THz wireless communication systems

    NASA Astrophysics Data System (ADS)

    Wang, Hanqing; Yuan, Weiwen; Zhang, Bo; Li, Huiyuan; Zhang, Zhuo; Yang, Xiaojie; Shi, Weixun

    2015-11-01

    Designed for space application, the paper presents the design, test and application of the front end in 0.3THz wireless communication. After test and fabrication, the terahertz wireless system is completed and indicates that HD video signals have been transmitted over a distance of 14m at the data rate of 1.5Gbps. The study shows the overall course of the test and application of the front end in wireless communication.

  2. Cognitive Wireless Communications - A paradigm shift in dealing with radio resources as a prerequisite for the wireless network of the future - An overview on the topic of cognitive wireless technologies

    NASA Astrophysics Data System (ADS)

    Haustein, Thomas; Stanczak, Slawomir; Wolisz, Adam; Jondral, Friedrich; Schotten, Hans; Kraemer, Rolf; Mück, Markus; Mennenga, Horst; Bender, Paul

    2016-07-01

    Wireless radio communications systems form the basis for mobile network connections in the digital society. A limited amount of radio spectrum and a spatially densified use of wireless communications systems require a resource-efficient use of the spectrum. Mechanisms of cognitive radio may hold the key to a more efficient use of the available spectrum under consideration of quality of service requirements. These mechanisms take advantage of location-specific knowledge of the wireless channel occupation in the dimensions of frequency, time, location and direction in space and therefore enable co-existent and reliable wireless communication. The authors give an introduction to the status of cognitive wireless communication technology, which represents the starting point of a series of research projects promoted by BMBF during 2012-2014.

  3. R&D on wireless broadband communication systems: new generation ubiquitous mobile network

    NASA Astrophysics Data System (ADS)

    Ogawa, Hiroyo

    2007-09-01

    R&D on new generation mobile network has attracted a growing interest over the world on the background of rapid market growth for 2nd and 3rd - generation cellular networks and wireless LANs/MANs. The National Institute of Information and Communications Technology (NICT) has been carried out the New Generation Mobile Network Project from April 2002 to March 2006, and has developed fundamental technologies to enable seamless and secure integration of various wireless access networks such as existing cellular networks, wireless LANs, home networks, intelligent transport systems (ITS), the Beyond-3G (B3G) cellular and other wireless access systems. From April 2006, Ubiquitous Mobile Network project focused on cognitive radio technology and integrated seamless networking technology was started. This paper overviews the achievement and the future plan of these projects.

  4. DOWNHOLE POWER GENERATION AND WIRELESS COMMUNICATIONS FOR INTELLIGENT COMPLETIONS APPLICATIONS

    SciTech Connect

    Paul Tubel

    2005-05-08

    The wireless gauge has not been modified or upgraded during this report period. Tubel Tech is working with the DoE Rocky Mountain test center to create a CRADA to allow Tubel Tech to test its tool in a well at the test center.

  5. Wireless communication with implanted medical devices using the conductive properties of the body

    PubMed Central

    Ferguson, John E; Redish, A David

    2013-01-01

    Many medical devices that are implanted in the body use wires or wireless radiofrequency telemetry to communicate with circuitry outside the body. However, the wires are a common source of surgical complications, including breakage, infection and electrical noise. In addition, radiofrequency telemetry requires large amounts of power and results in low-efficiency transmission through biological tissue. As an alternative, the conductive properties of the body can be used to enable wireless communication with implanted devices. In this article, several methods of intrabody communication are described and compared. In addition to reducing the complications that occur with current implantable medical devices, intrabody communication can enable novel types of miniature devices for research and clinical applications. PMID:21728728

  6. 77 FR 70464 - Certain Electronic Devices, Including Wireless Communication Devices, Portable Music and Data...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-26

    ... Telecommunications America, LLC of Richardson, Texas (collectively, ``Samsung''). 76 FR 45860 (Aug. 1, 2011). The... Presidential Memorandum of July 21, 2005, 70 FR 43251 (July 26, 2005). During this period, the subject articles... COMMISSION Certain Electronic Devices, Including Wireless Communication Devices, Portable Music and...

  7. 78 FR 16865 - Certain Electronic Devices, Including Wireless Communication Devices, Portable Music and Data...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-19

    ... America, LLC of Richardson, Texas (collectively, ``Samsung''). 76 FR 45860 (Aug. 1, 2011). The complaint... Commission, and on the issues of remedy, the public interest, and bonding. 77 FR 70464. The Commission... COMMISSION Certain Electronic Devices, Including Wireless Communication Devices, Portable Music and...

  8. 77 FR 28621 - Certain Wireless Communication Devices, Portable Music and Data Processing Devices, Computers and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-15

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Wireless Communication Devices, Portable Music and Data Processing Devices, Computers and Components Thereof; Notice of Request for Statements on the Public Interest AGENCY: U.S. International...

  9. An Ultra Low Cost Wireless Communications Laboratory for Education and Research

    ERIC Educational Resources Information Center

    Linn, Y.

    2012-01-01

    This paper presents an ultra-low-cost wireless communications laboratory that is based on a commercial off-the-shelf field programmable gate array (FPGA) development board that is both inexpensive and available worldwide. The total cost of the laboratory is under USD $200, but it includes complete transmission, channel emulation, reception…

  10. 78 FR 6344 - Certain Wireless Communications Base Stations and Components Thereof Notice of Receipt of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-30

    ...Notice is hereby given that the U.S. International Trade Commission has received a complaint entitled Certain Wireless Communications Base Stations and Components Thereof, DN 2934; the Commission is soliciting comments on any public interest issues raised by the complaint or complainant's filing under section 210.8(b) of the Commission's Rules of Practice and Procedure (19 CFR...

  11. Cryptanalysis of an Improved User Authentication Scheme with User Anonymity for Wireless Communications

    NASA Astrophysics Data System (ADS)

    Yoon, Eun-Jun; Yoo, Kee-Young

    A user identity anonymity is an important property for roaming services. In 2011, Kang et al. proposed an improved user authentication scheme that guarantees user anonymity in wireless communications. This letter shows that Kang et al.'s improved scheme still cannot provide user anonymity as they claimed.

  12. A Combined Radio and Underwater Wireless Optical Communication System based on Buoys

    NASA Astrophysics Data System (ADS)

    Song, Yuhang; Tong, Zheng; Cong, Bo; Yu, Xiangyu; Kong, Meiwei; Lin, Aobo

    2016-02-01

    We propose a system of combining radio and underwater wireless optical communication based on buoys for real-time image and video transmission between underwater vehicles and the base station on the shore. We analysis how the BER performance is affected by the link distance and the deflection angle of the light source using Monte Carlo simulation.

  13. 75 FR 44282 - In the Matter of Certain Mobile Telephones and Wireless Communication Devices Featuring Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-28

    ... Company of Rochester, New York on January 14, 2010, and supplemented on February 4, 2010. 75 FR 8112. The... Cameras, and Components Thereof; Notice of Commission Determination To Review Initial Determination AGENCY... importation of certain mobile telephones and wireless communication devices featuring digital cameras,...

  14. Wireless Communication for Controlling Microgrids: Co-simulation and Performance Evaluation

    SciTech Connect

    Mao, Rukun; Xu, Yan; Li, Huijuan; Li, Husheng

    2013-01-01

    A microgrid with wireless communication links for microgrid control has been designed and developed. The complete simulation model has been developed in MatLab SimuLink with seamless integration of the power subsystem and the communication subsystem. Unlike the conventional co-simulators that usually glue two existing simulators together by creating an interface, which has a steep learning curve, the proposed simulator is a compact single-unit model. Detailed modeling of the power subsystem and communication system is presented as well as the microgrid control architecture and strategies. The impact of different communication system performances on microgrid control has been studied and evaluated in the proposed simulator.

  15. 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.

  16. Multi-carrier transmission for hybrid radio frequency with optical wireless communications

    NASA Astrophysics Data System (ADS)

    Wang, Gang; Chen, Genshe; Shen, Dan; Pham, Khanh; Blasch, Erik; Nguyen, Tien M.

    2015-05-01

    Radio frequency (RF) wireless communication is reaching its capacity to support large data rate transmissions due to hardware constraints (e.g., silicon processes), software strategies (e.g., information theory), and consumer desire for timely large file exchanges (e.g., big data and mobile cloud computing). A high transmission rate performance must keep pace with the generated huge volumes of data for real-time processing. Integrated RF and optical wireless communications (RF/OWC) could be the next generation transmission technology to satisfy both the increased data rate exchange and the communications constraints. However, with the promising benefits of RF/OWC, challenges remain to fully develop hybrid RF with wireless optical communications such as uniform waveform design for information transmission and detection. In this paper, an orthogonal frequency division multiplexing (OFDM) transmission scheme, which widely employed in RF communications, is developed for optical communications. The traditional high peak-to-average power ratio (PAPR) in OFDM is reduced to improve system performance. The proposed multi-carrier waveform is evaluated with a frequency-selective fading channel. The results demonstrate that bit error rate (BER) performance of our proposed optical OFDM transmission technique outperforms the traditional OWC on-off keying (OOK) transmission scheme.

  17. Power-rate-distortion analysis for wireless video communication under energy constraint

    NASA Astrophysics Data System (ADS)

    He, Zhihai; Liang, Yongfang; Ahmad, Ishfaq

    2004-01-01

    In video coding and streaming over wireless communication network, the power-demanding video encoding operates on the mobile devices with limited energy supply. To analyze, control, and optimize the rate-distortion (R-D) behavior of the wireless video communication system under the energy constraint, we need to develop a power-rate-distortion (P-R-D) analysis framework, which extends the traditional R-D analysis by including another dimension, the power consumption. Specifically, in this paper, we analyze the encoding mechanism of typical video encoding systems and develop a parametric video encoding architecture which is fully scalable in computational complexity. Using dynamic voltage scaling (DVS), a hardware technology recently developed in CMOS circuits design, the complexity scalability can be translated into the power consumption scalability of the video encoder. We investigate the rate-distortion behaviors of the complexity control parameters and establish an analytic framework to explore the P-R-D behavior of the video encoding system. Both theoretically and experimentally, we show that, using this P-R-D model, the encoding system is able to automatically adjust its complexity control parameters to match the available energy supply of the mobile device while maximizing the picture quality. The P-R-D model provides a theoretical guideline for system design and performance optimization in wireless video communication under energy constraint, especially over the wireless video sensor network.

  18. Cooperative MIMO Communication at Wireless Sensor Network: An Error Correcting Code Approach

    PubMed Central

    Islam, Mohammad Rakibul; Han, Young Shin

    2011-01-01

    Cooperative communication in wireless sensor network (WSN) explores the energy efficient wireless communication schemes between multiple sensors and data gathering node (DGN) by exploiting multiple input multiple output (MIMO) and multiple input single output (MISO) configurations. In this paper, an energy efficient cooperative MIMO (C-MIMO) technique is proposed where low density parity check (LDPC) code is used as an error correcting code. The rate of LDPC code is varied by varying the length of message and parity bits. Simulation results show that the cooperative communication scheme outperforms SISO scheme in the presence of LDPC code. LDPC codes with different code rates are compared using bit error rate (BER) analysis. BER is also analyzed under different Nakagami fading scenario. Energy efficiencies are compared for different targeted probability of bit error pb. It is observed that C-MIMO performs more efficiently when the targeted pb is smaller. Also the lower encoding rate for LDPC code offers better error characteristics. PMID:22163732

  19. Network Efficient Power Control for Wireless Communication Systems

    PubMed Central

    Campos-Delgado, Daniel U.; Luna-Rivera, Jose Martin; Martinez-Sánchez, C. J.; Gutierrez, Carlos A.; Tecpanecatl-Xihuitl, J. L.

    2014-01-01

    We introduce a two-loop power control that allows an efficient use of the overall power resources for commercial wireless networks based on cross-layer optimization. This approach maximizes the network's utility in the outer-loop as a function of the averaged signal to interference-plus-noise ratio (SINR) by considering adaptively the changes in the network characteristics. For this purpose, the concavity property of the utility function was verified with respect to the SINR, and an iterative search was proposed with guaranteed convergence. In addition, the outer-loop is in charge of selecting the detector that minimizes the overall power consumption (transmission and detection). Next the inner-loop implements a feedback power control in order to achieve the optimal SINR in the transmissions despite channel variations and roundtrip delays. In our proposal, the utility maximization process and detector selection and feedback power control are decoupled problems, and as a result, these strategies are implemented at two different time scales in the two-loop framework. Simulation results show that substantial utility gains may be achieved by improving the power management in the wireless network. PMID:24683350

  20. A mobile robots experimental environment with event-based wireless communication.

    PubMed

    Guinaldo, María; Fábregas, Ernesto; Farias, Gonzalo; Dormido-Canto, Sebastián; Chaos, Dictino; Sánchez, José; Dormido, Sebastián

    2013-01-01

    An experimental platform to communicate between a set of mobile robots through a wireless network has been developed. The mobile robots get their position through a camera which performs as sensor. The video images are processed in a PC and a Waspmote card sends the corresponding position to each robot using the ZigBee standard. A distributed control algorithm based on event-triggered communications has been designed and implemented to bring the robots into the desired formation. Each robot communicates to its neighbors only at event times. Furthermore, a simulation tool has been developed to design and perform experiments with the system. An example of usage is presented. PMID:23881139

  1. Addendum to "Quantum wireless multihop communication based on arbitrary Bell pairs and teleportation"

    NASA Astrophysics Data System (ADS)

    Wang, Kan; Gong, Yan-Xiao; Yu, Xu-Tao; Lu, Sheng-Li

    2014-10-01

    In our previous work [Phys. Rev. A 89, 022329 (2014), 10.1103/PhysRevA.89.022329], we proposed a teleportation-based quantum communication scheme in a quantum wireless multihop network with arbitrary types of Bell pairs shared between adjacent nodes. Here we revised the scheme by introducing a result-mapping method for halving the classical communication cost, with which the source and intermediate nodes map the measurement outcomes to those corresponding to the target Bell pair type assigned by the destination node. A routing protocol is utilized to piggyback the target Bell pair type notification information which introduces no extra communication cost.

  2. A Mobile Robots Experimental Environment with Event-Based Wireless Communication

    PubMed Central

    Guinaldo, María; Fábregas, Ernesto; Farias, Gonzalo; Dormido-Canto, Sebastián; Chaos, Dictino; Sánchez, José; Dormido, Sebastián

    2013-01-01

    An experimental platform to communicate between a set of mobile robots through a wireless network has been developed. The mobile robots get their position through a camera which performs as sensor. The video images are processed in a PC and a Waspmote card sends the corresponding position to each robot using the ZigBee standard. A distributed control algorithm based on event-triggered communications has been designed and implemented to bring the robots into the desired formation. Each robot communicates to its neighbors only at event times. Furthermore, a simulation tool has been developed to design and perform experiments with the system. An example of usage is presented. PMID:23881139

  3. Coherent Terahertz Wireless Signal Transmission Using Advanced Optical Fiber Communication Technology

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

    Coherent terahertz signal transmission with multilevel modulation and demodulation is demonstrated using an optical sub-harmonic IQ mixer (SHIQM), which consists of optical components in advanced optical fiber communication technologies. An optical-frequency-comb-employed signal generator is capable of vector modulation as well as frequency tunability. Digital signal processing (DSP) adopted from the recently developed optical digital coherent communication can easily demodulate multi-level modulated terahertz signals by using electrical heterodyning for intermediate-frequency (IF) down conversion. This technique is applicable for mobile backhauling in the next-generation mobile communication technology directly connected to an optical fiber network as a high-speed wireless transmission link.

  4. Channel capacity study of underwater wireless optical communications links based on Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Li, Jing; Ma, Yong; Zhou, Qunqun; Zhou, Bo; Wang, Hongyuan

    2012-01-01

    Channel capacity of ocean water is limited by propagation distance and optical properties. Previous studies on this problem are based on water-tank experiments with different amounts of Maalox antacid. However, propagation distance is limited by the experimental set-up and the optical properties are different from ocean water. Therefore, the experiment result is not accurate for the physical design of underwater wireless communications links. This letter developed a Monte Carlo model to study channel capacity of underwater optical communications. Moreover, this model can flexibly configure various parameters of transmitter, receiver and channel, and is suitable for physical underwater optical communications links design.

  5. Software design of optical link for indoor wireless optical communication network used LEDs as source visible light communication

    NASA Astrophysics Data System (ADS)

    Liner, Andrej; Papes, Martin; Jaros, Jakub; Koudelka, Petr; Latal, Jan; Vitasek, Jan; Hajek, Lukas; Vasinek, Vladimir

    2015-01-01

    Nowadays, the conventional light sources are replaced progressively evolving LED (Light Emitting Diode) for their deficient properties. This technology recorded dynamic growth mainly due to effective research in increasing power density and choice the color shade on good color rendering CRI (Color Rendering Index). This extending the zone of used LEDs. Development of lighting technology by means of white power LEDs provided impulse to the idea of the development of optical wireless data networks based on optical radiation in the visible region of the spectrum VLC (Visible Light Communications). In the last years being recorded a turnover of research from transmission of information via optical fiber to the transmission of information through wireless networks. At the same time the concept of information transmission by indirect sight between transmitter and receiver NLOS (Non Line of Sight) is changing. Line of research focuses mainly on the direct line of sight LOS (Line of Sight). This is due to the development of the semiconductor lighting through the white power LED. This is connected with the idea of using them as a transmitter for communication purposes. This article deals with software design of optical link for indoor wireless optical network in LightTools software. Optimal optical source was designed for communication using LED as the first. For the proposed type of LEDs sources were used different shapes and distances distribution between LEDs in a single cell at the designed optical transmitter.

  6. An interactive wireless communication system for visually impaired people using city bus transport.

    PubMed

    Wang, Hsiao-Lan; Chen, Ya-Ping; Rau, Chi-Lun; Yu, Chung-Huang

    2014-05-01

    Visually impaired people have difficulty accessing information about public transportation systems. Several systems have been developed for assisting visually impaired and blind people to use the city bus. Most systems provide only one-way communication and require high-cost and complex equipment. The purpose of this study is to reduce the difficulties faced by visually impaired people when taking city buses, using an interactive wireless communication system. The system comprised a user module and a bus module to establish a direct one-to-one connection. When the user inputs 4-digit numbers, the user module immediately sends out the information. If the bus module receives the matched bus number, it buzzes and the warning LED flashes to notify the bus driver that someone is waiting to board on the bus. User tests were conducted by two visually impaired people in a simulated vehicle and a city bus. The success rate of interactive wireless communication, recognizing the arrival of the bus and boarding the correct bus reached 100% in all of the tests. The interactive wireless communication aid system is a valid and low-cost device for assisting visually impaired people to use city buses. PMID:24776720

  7. An Interactive Wireless Communication System for Visually Impaired People Using City Bus Transport

    PubMed Central

    Wang, Hsiao-Lan; Chen, Ya-Ping; Rau, Chi-Lun; Yu, Chung-Huang

    2014-01-01

    Visually impaired people have difficulty accessing information about public transportation systems. Several systems have been developed for assisting visually impaired and blind people to use the city bus. Most systems provide only one-way communication and require high-cost and complex equipment. The purpose of this study is to reduce the difficulties faced by visually impaired people when taking city buses, using an interactive wireless communication system. The system comprised a user module and a bus module to establish a direct one-to-one connection. When the user inputs 4-digit numbers, the user module immediately sends out the information. If the bus module receives the matched bus number, it buzzes and the warning LED flashes to notify the bus driver that someone is waiting to board on the bus. User tests were conducted by two visually impaired people in a simulated vehicle and a city bus. The success rate of interactive wireless communication, recognizing the arrival of the bus and boarding the correct bus reached 100% in all of the tests. The interactive wireless communication aid system is a valid and low-cost device for assisting visually impaired people to use city buses. PMID:24776720

  8. An Energy-efficient Rate Adaptive Media Access Protocol (RA-MAC) for Long-lived Sensor Networks

    PubMed Central

    Hu, Wen; Chen, Quanjun; Corke, Peter; O’Rourke, Damien

    2010-01-01

    We introduce an energy-efficient Rate Adaptive Media Access Control (RA-MAC) algorithm for long-lived Wireless Sensor Networks (WSNs). Previous research shows that the dynamic and lossy nature of wireless communications is one of the major challenges to reliable data delivery in WSNs. RA-MAC achieves high link reliability in such situations by dynamically trading off data rate for channel gain. The extra gain that can be achieved reduces the packet loss rate which contributes to reduced energy expenditure through a reduced numbers of retransmissions. We achieve this at the expense of raw bit rate which generally far exceeds the application’s link requirement. To minimize communication energy consumption, RA-MAC selects the optimal data rate based on the estimated link quality at each data rate and an analytical model of the energy consumption. Our model shows how the selected data rate depends on different channel conditions in order to minimize energy consumption. We have implemented RA-MAC in TinyOS for an off-the-shelf sensor platform (the TinyNode) on top of a state-of-the-art WSN Media Access Control Protocol, SCP-MAC, and evaluated its performance by comparing our implementation with the original SCP-MAC using both simulation and experiment. PMID:22219675

  9. An energy-efficient rate adaptive media access protocol (RA-MAC) for long-lived sensor networks.

    PubMed

    Hu, Wen; Chen, Quanjun; Corke, Peter; O'Rourke, Damien

    2010-01-01

    We introduce an energy-efficient Rate Adaptive Media Access Control (RA-MAC) algorithm for long-lived Wireless Sensor Networks (WSNs). Previous research shows that the dynamic and lossy nature of wireless communications is one of the major challenges to reliable data delivery in WSNs. RA-MAC achieves high link reliability in such situations by dynamically trading off data rate for channel gain. The extra gain that can be achieved reduces the packet loss rate which contributes to reduced energy expenditure through a reduced numbers of retransmissions. We achieve this at the expense of raw bit rate which generally far exceeds the application's link requirement. To minimize communication energy consumption, RA-MAC selects the optimal data rate based on the estimated link quality at each data rate and an analytical model of the energy consumption. Our model shows how the selected data rate depends on different channel conditions in order to minimize energy consumption. We have implemented RA-MAC in TinyOS for an off-the-shelf sensor platform (the TinyNode) on top of a state-of-the-art WSN Media Access Control Protocol, SCP-MAC, and evaluated its performance by comparing our implementation with the original SCP-MAC using both simulation and experiment. PMID:22219675

  10. Underwater Wireless Sensor Communications in the 2.4 GHz ISM Frequency Band

    PubMed Central

    Lloret, Jaime; Sendra, Sandra; Ardid, Miguel; Rodrigues, Joel J. P. C.

    2012-01-01

    One of the main problems in underwater communications is the low data rate available due to the use of low frequencies. Moreover, there are many problems inherent to the medium such as reflections, refraction, energy dispersion, etc., that greatly degrade communication between devices. In some cases, wireless sensors must be placed quite close to each other in order to take more accurate measurements from the water while having high communication bandwidth. In these cases, while most researchers focus their efforts on increasing the data rate for low frequencies, we propose the use of the 2.4 GHz ISM frequency band in these special cases. In this paper, we show our wireless sensor node deployment and its performance obtained from a real scenario and measures taken for different frequencies, modulations and data transfer rates. The performed tests show the maximum distance between sensors, the number of lost packets and the average round trip time. Based on our measurements, we provide some experimental models of underwater communication in fresh water using EM waves in the 2.4 GHz ISM frequency band. Finally, we compare our communication system proposal with the existing systems. Although our proposal provides short communication distances, it provides high data transfer rates. It can be used for precision monitoring in applications such as contaminated ecosystems or for device communicate at high depth. PMID:22666029

  11. Underwater wireless sensor communications in the 2.4 GHz ISM frequency band.

    PubMed

    Lloret, Jaime; Sendra, Sandra; Ardid, Miguel; Rodrigues, Joel J P C

    2012-01-01

    One of the main problems in underwater communications is the low data rate available due to the use of low frequencies. Moreover, there are many problems inherent to the medium such as reflections, refraction, energy dispersion, etc., that greatly degrade communication between devices. In some cases, wireless sensors must be placed quite close to each other in order to take more accurate measurements from the water while having high communication bandwidth. In these cases, while most researchers focus their efforts on increasing the data rate for low frequencies, we propose the use of the 2.4 GHz ISM frequency band in these special cases. In this paper, we show our wireless sensor node deployment and its performance obtained from a real scenario and measures taken for different frequencies, modulations and data transfer rates. The performed tests show the maximum distance between sensors, the number of lost packets and the average round trip time. Based on our measurements, we provide some experimental models of underwater communication in fresh water using EM waves in the 2.4 GHz ISM frequency band. Finally, we compare our communication system proposal with the existing systems. Although our proposal provides short communication distances, it provides high data transfer rates. It can be used for precision monitoring in applications such as contaminated ecosystems or for device communicate at high depth. PMID:22666029

  12. Use of LSP in securing wireless LAN communications

    NASA Astrophysics Data System (ADS)

    Newman, Richard E.; Bouldin, B.; Broccard, Phillipe; Coscenza, Thomas; Farago, Steve; Hoyt, Mark; Nolan, Keith; Sanders, Mark; Swanson, Tim; Winner, Joe

    2000-11-01

    The Layered Service Provider (LSP) is a mechanism available in Microsoft Windows 95 and Windows 98 to insert a protocol layer between the Winsock library calls and the transport layer of the network protocol stack. This paper discusses the use of encryption at the LSP to provide for security on wireless LANs that is transparent to the applications. Use of the LSP allows similarly transparent cryptographic isolation over any medium that may be accessed by the network protocol stack. Hardware-based cryptography in the form of Fortezza cards was used for this project, but the approach works just as well with software-based cryptography. The system was developed jointly by teams at the University of Florida in its Integrated Process and Product Design (IPPD) course and a liaison engineer at Raytheon Systems Division.

  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. Modeling of optical wireless scattering communication channels over broad spectra.

    PubMed

    Liu, Weihao; Zou, Difan; Xu, Zhengyuan

    2015-03-01

    The air molecules and suspended aerosols help to build non-line-of-sight (NLOS) optical scattering communication links using carriers from near infrared to visible light and ultraviolet bands. This paper proposes channel models over such broad spectra. Wavelength dependent Rayleigh and Mie scattering and absorption coefficients of particles are analytically obtained first. They are applied to the ray tracing based Monte Carlo method, which models the photon scattering angle from the scatterer and propagation distance between two consecutive scatterers. Communication link path loss is studied under different operation conditions, including visibility, particle density, wavelength, and communication range. It is observed that optimum communication performances exist across the wavelength under specific atmospheric conditions. Infrared, visible light and ultraviolet bands show their respective features as conditions vary. PMID:26366662

  15. Wireless communication in the airflow verification system of biological safety cabinet

    NASA Astrophysics Data System (ADS)

    Zhang, Yu-de; Hou, De-xin; Qiu, Jian; Ye, Shu-liang

    2013-01-01

    In recent years, biological safety cabinet has been applied widely and urgently to the biochemistry laboratory. An increasing research need has been asked about the processing safety of the workers. In this safety cabinet system, among series of related factors, the main parameter is airflow velocity. At percent, this measuring work is usually done by processional workers, thus leading to the low efficiency and disadvantages. In this paper, a new method was approved to deal with the current problem, where wireless communication controller and detector. According to the experimental data and the comparison between the two methods, the wireless way is more convenient and more efficient than previous one, and the working distance can be about 730 meters. Meanwhile, the communication system has already been used in Guangzhou Institute of Metrology Laboratory.

  16. 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.

  17. Trade-Offs for Wireless Transcutaneous RF Communication in Biotelemetric Applications

    NASA Astrophysics Data System (ADS)

    Pitz, Inke; Hall, Leonard T.; Hansen, Hedley J.; Varadan, Vijay K.; Bertram, Chris D.; Maddocks, Simon; Enderling, Stefan; Saint, David; Al-Sarawi, Said F.; Abbott, Derek

    2002-11-01

    The application of biotelemetry in the case of a RF controllable microvalve is discussed. Biotelemetry implies the contactless measurement of different electrical and nonelectrical parameters measured on human or animal subjects. A biotelemetry system consists of a transmitter and a receiver with a transmission link in-between. Transmitted information can be a biopotential or a nonelectric value like arterial pressure, respiration, body temperature or pH value. Transducers convert nonelectrical values into electrical signals. Radio frequency (RF) telemetry allows a patient greater mobility. Above all, the application of wireless communication becomes more and more popular in microinvasive surgery. Battery powered implants are most commonly used, but batteries must be changed after a period of time. To avoid this, wireless transcutaneous radio frequency (RF) communication is proposed for the powering and control of medical implants.

  18. Panoramic alignment system for optical wireless communication systems

    NASA Astrophysics Data System (ADS)

    Shen, Thomas C.; Drost, Robert J.; Rzasa, John; Sadler, Brian M.; Davis, Christopher C.

    2015-03-01

    Free space optical communication may provide a viable adjunct to radio frequency (RF) technology for mobile communications, especially in "RF-denied" settings in which RF-based communication may be prohibited or impractical. These settings may include military tactical environments or settings which suffer from RF jamming or interference. Unlike many RF communication systems, point-to-point optical communications between mobile nodes typically require establishing and maintaining alignment, which requires each node to have awareness of the locations of neighboring nodes. We propose a method to create this situational awareness between nodes using purely optical means. This method uses a camera that is focused on a hyperboloidal mirror, thus providing a 360-degree view of the surrounding environment. The camera and mirror are used to detect light emitted from the beacon transmitters from neighboring nodes, with the location of the beacon image in the sensor plane of the camera yielding elevation and azimuth information of the beacon. The beacon transmitter itself is modulated, allowing it to be distinguished from the environment. In discussing our experimental realization of this system, we assess its performance.

  19. Progress on the Development of Future Airport Surface Wireless Communications Network

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Budinger, James M.; Brooks, David E.; Franklin, Morgan; DeHart, Steve; Dimond, Robert P.; Borden, Michael

    2009-01-01

    Continuing advances in airport surface management and improvements in airport surface safety are required to enable future growth in air traffic throughout the airspace, as airport arrival and departure delays create a major system bottleneck. These airport management and safety advances will be built upon improved communications, navigation, surveillance, and weather sensing, creating an information environment supporting system automation. The efficient movement of the digital data generated from these systems requires an underlying communications network infrastructure to connect data sources with the intended users with the required quality of service. Current airport surface communications consists primarily of buried copper or fiber cable. Safety related communications with mobile airport surface assets occurs over 25 kHz VHF voice and data channels. The available VHF spectrum, already congested in many areas, will be insufficient to support future data traffic requirements. Therefore, a broadband wireless airport surface communications network is considered a requirement for the future airport component of the air transportation system. Progress has been made on defining the technology and frequency spectrum for the airport surface wireless communications network. The development of a test and demonstration facility and the definition of required testing and standards development are now underway. This paper will review the progress and planned future work.

  20. Evaluation of the EFCOM SC-100M/120M/125M wireless underwater communicator

    NASA Astrophysics Data System (ADS)

    Middleton, J. R.

    1982-04-01

    In June 1981, the EFCOM SC-100M/120M/125M wireless communications system was evaluated in conjunction with the AGA DIVATOR 324 Full-Face Mask by the Navy Experimental Diving Unit. The purpose was to determine the systems suitability for U.S. Navy use with open-circuit Self-Contained Underwater Breathing Apparatus (SCUBA). The EFCOM system was evaluated for intelligibility, reliability and human engineering.

  1. A maritime wireless communication primitive power-supplied by GPS

    NASA Astrophysics Data System (ADS)

    Zhou, Youling; Liu, Angli; Du, Wencai; Zhang, Yonghui

    2014-10-01

    As global positioning systems (GPS) are becoming ubiquitous, GPS signals are populating the space. While such signals have exclusively been used in localization services in the first place, we take the first step in turning them to energy sources for maritime communication. Specifically, we leverage antennas deployed on ships to harvest energy from such ambient GPS signals, which are also fed into encoders to carry information bits. This way, maritime communication can be built completely battery-free all day long. Also, it it because the communication takes place on the ocean, where no interference is introduced, except for the original GPS signals to the backscattered GPS signals, the design of the transceiver under certain energy budget is simplified. In this paper, we show the theoretical promise that the system would work using electromagnetic theories, and introduce our prototype which proves the concept in real world settings.

  2. A survey on M2M systems for mHealth: a wireless communications perspective.

    PubMed

    Kartsakli, Elli; Lalos, Aris S; Antonopoulos, Angelos; Tennina, Stefano; Renzo, Marco Di; Alonso, Luis; Verikoukis, Christos

    2014-01-01

    In the new era of connectivity, marked by the explosive number of wireless electronic devices and the need for smart and pervasive applications, Machine-to-Machine (M2M) communications are an emerging technology that enables the seamless device interconnection without the need of human interaction. The use of M2M technology can bring to life a wide range of mHealth applications, with considerable benefits for both patients and healthcare providers. Many technological challenges have to be met, however, to ensure the widespread adoption of mHealth solutions in the future. In this context, we aim to provide a comprehensive survey on M2M systems for mHealth applications from a wireless communication perspective. An end-to-end holistic approach is adopted, focusing on different communication aspects of the M2M architecture. Hence, we first provide a systematic review ofWireless Body Area Networks (WBANs), which constitute the enabling technology at the patient's side, and then discuss end-to-end solutions that involve the design and implementation of practical mHealth applications. We close the survey by identifying challenges and open research issues, thus paving the way for future research opportunities. PMID:25264958

  3. A Survey on M2M Systems for mHealth: A Wireless Communications Perspective

    PubMed Central

    Kartsakli, Elli; Lalos, Aris S.; Antonopoulos, Angelos; Tennina, Stefano; Di Renzo, Marco; Alonso, Luis; Verikoukis, Christos

    2014-01-01

    In the new era of connectivity, marked by the explosive number of wireless electronic devices and the need for smart and pervasive applications, Machine-to-Machine (M2M) communications are an emerging technology that enables the seamless device interconnection without the need of human interaction. The use of M2M technology can bring to life a wide range of mHealth applications, with considerable benefits for both patients and healthcare providers. Many technological challenges have to be met, however, to ensure the widespread adoption of mHealth solutions in the future. In this context, we aim to provide a comprehensive survey on M2M systems for mHealth applications from a wireless communication perspective. An end-to-end holistic approach is adopted, focusing on different communication aspects of the M2M architecture. Hence, we first provide a systematic review of Wireless Body Area Networks (WBANs), which constitute the enabling technology at the patient's side, and then discuss end-to-end solutions that involve the design and implementation of practical mHealth applications. We close the survey by identifying challenges and open research issues, thus paving the way for future research opportunities. PMID:25264958

  4. Video Transmission for Third Generation Wireless Communication Systems

    PubMed Central

    Gharavi, H.; Alamouti, S. M.

    2001-01-01

    This paper presents a twin-class unequal protected video transmission system over wireless channels. Video partitioning based on a separation of the Variable Length Coded (VLC) Discrete Cosine Transform (DCT) coefficients within each block is considered for constant bitrate transmission (CBR). In the splitting process the fraction of bits assigned to each of the two partitions is adjusted according to the requirements of the unequal error protection scheme employed. Subsequently, partitioning is applied to the ITU-T H.263 coding standard. As a transport vehicle, we have considered one of the leading third generation cellular radio standards known as WCDMA. A dual-priority transmission system is then invoked on the WCDMA system where the video data, after being broken into two streams, is unequally protected. We use a very simple error correction coding scheme for illustration and then propose more sophisticated forms of unequal protection of the digitized video signals. We show that this strategy results in a significantly higher quality of the reconstructed video data when it is transmitted over time-varying multipath fading channels.

  5. Decision feedback equalization for CDMA in indoor wireless communications

    NASA Astrophysics Data System (ADS)

    Abdulrahman, Majeed; Sheikh, Asrar U. H.; Falconer, David D.

    1994-05-01

    Commercial interest in Code Division Multiple Access (CDMA) systems has risen dramatically in the last few years. It yields a potential increase in capacity over other access schemes, because it provides protection against interference, multipath, fading, and jamming. Recently, several interference cancellation schemes for CDMA have been proposed but they require information about all interfering active users or some channel parameters. In this paper, we present an adaptive fractionally spaced decision feedback equalizer (DFE) for a CDMA system in an indoor wireless Rayleigh fading environment. This system only uses information about the desired user's spreading code and a training sequence. An analysis on the optimum performance of the DFE receiver shows the advantages of this system over others in terms of capacity improvements. A simulation of this system is also presented to study the convergence properties and implementation considerations of the DFE receiver. Effects on the performance because of sudden birth and death of users in the CDMA system and bit error rate performanceof the DFE receiver is also presented. of the DFE receiver is also presented.

  6. Optimum LED wavelength for underwater optical wireless communication at turbid water

    NASA Astrophysics Data System (ADS)

    Rosenkrantz, Etai; Arnon, Shlomi

    2014-10-01

    Underwater optical wireless communication is an emerging technology, which can provide high data rate. High data rate communication is required for applications such as underwater imaging, networks of sensors and swarms of underwater vehicles. These applications pursue an affordable light source, which can be obtained by light emitting diodes (LED). LEDs offer solutions characterized by low cost, high efficiency, reliability and compactness based on off-the-shelf components such as blue and green light emitting diodes. In this paper we present our recent theoretical and experimental results in this field.

  7. Adaptive QoS in 802.11e Wireless Networks for Lunar Communications

    NASA Technical Reports Server (NTRS)

    Spearman, Will; Martin, Jim; Gao, Jay L.

    2008-01-01

    This slide presentation reviews the issues around Adaptive Quality of Service (QoS) in wireless networks for lunar communications, and how a dynamic 802.11e standard meets the requirements for all aspects of communications for lunar surface missions. This paper focuses on the use of Enhanced Distributed Channel Access (EDCA). It includes a description of an adaptive QoS Algorithm, a review of the set up of the simulation of the 802.11e standard, and the results of the simulation are included.

  8. Wireless communication in health care: who will win the right to send data boldly where no data has gone before?

    PubMed

    Campbell, Robert J; Durigon, Louis

    2003-01-01

    Increasingly, health care professionals will need to retrieve, store, share, and send data using several types of wireless devices. These devices include personal digital assistants, laptops, Web tablets, cell phones, and clothing that monitor heart rate and blood pressure. Regardless of the device, several standards will vie for the right to provide the wireless communications link between the health care professional and the wired data resources located within a health care organization. This article identifies the top three technologies in the wireless communications field: Wireless Fidelity (WiFi), Mobile Communications, and Bluetooth; breaks down each according to its strengths and weaknesses; and makes recommendations for their use by health care professionals located inside and outside a health care facility. Where appropriate the discussion includes an explication of how a specific technology can be made secure from hackers and other security breeches. PMID:12956225

  9. FLYCON-R: Wireless Integrated Communication and Navigation System

    NASA Astrophysics Data System (ADS)

    Palomo, Jose Maria; Gomez de Aguero, Sergio; Latorre, Antonio; Fernandez, Antonio; Pina, Fernando; Tarziu, Andrei; Balan, Mugurel; Sanchez Gestido, Manuel; Concari, Paolo

    2015-09-01

    This paper presents the FLYCON-R system, which is an integrated communication and ranging system based on OFDM signal. FLYCON-R supports high data rates and flexible data communications, providing also relative ranging measurements based on Time of Arrival (ToA) from the Radio Frequency signals. Deimos Space (Spain and Romania) and ISS are carrying out the FLYCON-R project for ESA under the Romanian task force initiative. FLYCON-R (Prototype of Integrated Nav-Com sensor based on WiMax Standard for Formation Flying) aims to upgrade the previously existing FLYCON proof of concept (PoC) to a more advanced, elegant breadboard version, ready for on-ground flight testing and as near as possible to a future flight version. The paper presents as well the preliminary results of the flight tests performed on the Spanish R&D PERIGEO project, using the FLYCON PoC prototypes.

  10. Wireless sensor networks for planetary exploration: Experimental assessment of communication and deployment

    NASA Astrophysics Data System (ADS)

    Sanz, D.; Barrientos, A.; Garzón, M.; Rossi, C.; Mura, M.; Puccinelli, D.; Puiatti, A.; Graziano, M.; Medina, A.; Mollinedo, L.; de Negueruela, C.

    2013-09-01

    Planetary surface exploration is an appealing application of wireless sensor networks that has been investigated in recent years by the space community, including the European Space Agency. The idea is to deploy a number of self-organizing sensor nodes forming a wireless networked architecture to provide a distributed instrument for the study and exploration of a planetary body. To explore this concept, ESA has funded the research project RF Wireless for Planetary Exploration (RF-WIPE), carried out by GMV, SUPSI and UPM. The purpose of RF-WIPE was to simulate and prototype a wireless sensor network in order to assess the potential and limitations of the technology for the purposes of planetary exploration. In this paper, we illustrate the results of the work carried out within the context of RF-WIPE. Two test case scenarios have been investigated: a distributed sensor network-based instrument and networked planetary surface exploration. Each scenario is related to a particular network configuration. For such configurations, energy models and communication protocols have been developed, simulated, and validated both on laboratory tests and with outdoor field tests. Additionally, node deployment was investigated, and a deployment system based on a mobile robotics platform has been designed and tested.

  11. Wireless gas detection with a smartphone via rf communication.

    PubMed

    Azzarelli, Joseph M; Mirica, Katherine A; Ravnsbæk, Jens B; Swager, Timothy M

    2014-12-23

    Chemical sensing is of critical importance to human health, safety, and security, yet it is not broadly implemented because existing sensors often require trained personnel, expensive and bulky equipment, and have large power requirements. This study reports the development of a smartphone-based sensing strategy that employs chemiresponsive nanomaterials integrated into the circuitry of commercial near-field communication tags to achieve non-line-of-sight, portable, and inexpensive detection and discrimination of gas-phase chemicals (e.g., ammonia, hydrogen peroxide, cyclohexanone, and water) at part-per-thousand and part-per-million concentrations. PMID:25489066

  12. Wireless gas detection with a smartphone via rf communication

    PubMed Central

    Azzarelli, Joseph M.; Mirica, Katherine A.; Ravnsbæk, Jens B.; Swager, Timothy M.

    2014-01-01

    Chemical sensing is of critical importance to human health, safety, and security, yet it is not broadly implemented because existing sensors often require trained personnel, expensive and bulky equipment, and have large power requirements. This study reports the development of a smartphone-based sensing strategy that employs chemiresponsive nanomaterials integrated into the circuitry of commercial near-field communication tags to achieve non-line-of-sight, portable, and inexpensive detection and discrimination of gas-phase chemicals (e.g., ammonia, hydrogen peroxide, cyclohexanone, and water) at part-per-thousand and part-per-million concentrations. PMID:25489066

  13. A Model for QoS - Aware Wireless Communication in Hospitals.

    PubMed

    Alavikia, Zahra; Khadivi, Pejman; Hashemi, Masoud Reza

    2012-01-01

    In the recent decade, research regarding wireless applications in electronic health (e-Health) services has been increasing. The main benefits of using wireless technologies in e-Health applications are simple communications, fast delivery of medical information, reducing treatment cost and also reducing the medical workers' error rate. However, using wireless communications in sensitive healthcare environment raises electromagnetic interference (EMI). One of the most effective methods to avoid the EMI problem is power management. To this end, some of methods have been proposed in the literature to reduce EMI effects in health care environments. However, using these methods may result in nonaccurate interference avoidance and also may increase network complexity. To overcome these problems, we introduce two approaches based on per-user location and hospital sectoring for power management in sensitive healthcare environments. Although reducing transmission power could avoid EMI, it causes a number of successful message deliveries to the access point to decrease and, hence, the quality of service requirements cannot be meet. In this paper, we propose the use of relays for decreasing the probability of outage in the aforementioned scenario. Relay placement is the main factor to enjoy the usefulness of relay station benefits in the network and, therefore, we use the genetic algorithm to compute the optimum positions of a fixed number of relays. We have considered delay and maximum blind point coverage as two main criteria in relay station problem. The performance of the proposed method in outage reduction is investigated through simulations. PMID:23493832

  14. Infrared Communications for Small Spacecraft: From a Wireless Bus to Cluster Concepts

    NASA Technical Reports Server (NTRS)

    Webb, Suzanne C.; Schneider, Wolfger; Darrin, M. Ann G.; Boone, Bradley G.; Luers, Philip J.; Day, John H. (Technical Monitor)

    2001-01-01

    Nanosatellites operating singly or in clusters are anticipated for future space science missions. To implement this new communications paradigm, we are approaching cluster communications by first developing an infrared (IR) intra-craft wireless bus capability, following initially the MIL-STD-1553B protocol. Benefits of an IR wireless bus are low mass, size, power, and cost, simplicity of implementation, ease of use, minimum EMI, and efficient and reliable data transfer. Our goals are to maximize the reliable link margin in order to afford greater flexibility in receiver placement, which will ease technology insertion. We have developed a concept demonstration using a high-speed visible-band silicon PIN photodiode and a high-efficiency visible LED operating at a data rate up to 4 Mb/sec. In designing an internal IR wireless bus, we have characterized various candidate materials, emitters, and geometries, assuming a single reflection. Thus, we have measured the bidirectional reflectance distribution function (BRDF) for five different materials characteristic of typical spacecraft structures, which range from nearly Lambertian to highly specular. We have fit our data to empirical BRDF functions and modeled the detected irradiance anywhere in the plane of incidence for a divergent (LED) emitter. We have also determined the angular limits on the link geometry to remain within the required bit error rate by determining the received signal-to-noise ratio (SNR) for minimum values of irradiance received at the detector.

  15. Secure Intra-Body Wireless Communications (SIWiC) System Project

    NASA Technical Reports Server (NTRS)

    Ahmad, Aftab; Doggett, Terrence P.

    2011-01-01

    SIWiC System is a project to investigate, design and implement future wireless networks of implantable sensors in the body. This futuristic project is designed to make use of the emerging and yet-to-emerge technologies, including ultra-wide band (UWB) for wireless communications, smart implantable sensors, ultra low power networking protocols, security and privacy for bandwidth and power deficient devices and quantum computing. Progress in each of these fronts is hindered by the needs of breakthrough. But, as we will see in this paper, these major challenges are being met or will be met in near future. SIWiC system is a network of in-situ wireless devices that are implanted to coordinate sensed data inside the body, such as symptoms monitoring collected internally, or biometric data collected of an outside object from within the intra-body network. One node has the capability of communicating outside the body to send data or alarm to a relevant authority, e.g., a remote physician.

  16. Infrared communications for small spacecraft: from a wireless bus to cluster concepts

    NASA Astrophysics Data System (ADS)

    Walts, Suzanne C.; Schneider, Wolfger; Darrin, Margaret A. G.; Boone, Bradley G.; Luers, Philip J.

    2001-08-01

    Nanosatellites operating singly or in clusters are anticipated for future space science missions. To implement this new communications paradigm, we are approaching cluster communications by first developing an infrared (IR) intra- craft wireless bus capability, following initially the MIL- STD-1553B protocol. Benefits of an IR wireless bus are low mass, size, power, and cost, simplicity of implementation, ease of use, minimum EMI, and efficient and reliable data transfer. Our goals are to maximize the reliable link margin in order to afford greater flexibility in receiver placement, which will ease technology insertion. We have developed a concept demonstration using a high-speed visible-band silicon PIN photodiode and a high-efficiency visible LED operating at a data rate up to 4 Mb/sec. In designing an internal IR wireless bus, we have characterized various candidate materials, emitters, and geometries, assuming a single reflection. Thus, we have measured the bidirectional reflectance distribution function (BRDF) for five different materials characteristic of typical spacecraft structures, which range from nearly Lambertian to highly specular. We have fit our data to empirical BRDF functions and modeled the detected irradiance anywhere in the plane of incidence for a divergent emitter. We have also determined the angular limits on the link geometry to remain within the required bit error rate by determining the received signal-to-noise ratio for minimum values of irradiance received at the detector.

  17. Underwater optical wireless communications: depth dependent variations in attenuation.

    PubMed

    Johnson, Laura J; Green, Roger J; Leeson, Mark S

    2013-11-20

    Depth variations in the attenuation coefficient for light in the ocean were calculated using a one-parameter model based on the chlorophyll-a concentration C(c) and experimentally-determined Gaussian chlorophyll-depth profiles. The depth profiles were related to surface chlorophyll levels for the range 0-4  mg/m², representing clear, open ocean. The depth where C(c) became negligible was calculated to be shallower for places of high surface chlorophyll; 111.5 m for surface chlorophyll 0.8communication links, calculated to be 0.0092  m⁻¹ at a wavelength of 430 nm. By combining this with satellite surface-chlorophyll data, it is possible to quantify the attenuation between any two locations in the ocean, with applications for low-noise or secure underwater communications and vertical links from the ocean surface. PMID:24513735

  18. Spread Spectrum Based Energy Efficient Collaborative Communication in Wireless Sensor Networks

    PubMed Central

    2016-01-01

    Wireless sensor networks consist of resource limited devices. Most crucial of these resources is battery life, as in most applications like battle field or volcanic area monitoring, it is often impossible to replace or recharge the power source. This article presents an energy efficient collaborative communication system based on spread spectrum to achieve energy efficiency as well as immunity against jamming, natural interference, noise suppression and universal frequency reuse. Performance of the proposed system is evaluated using the received signal power, bit error rate (BER) and energy consumption. The results show a direct proportionality between the power gain and the number of collaborative nodes as well as BER and signal-to-noise ratio (Eb/N0). The analytical and simulation results of the proposed system are compared with SISO system. The comparison reveals that SISO perform better than collaborative communication in case of small distances whereas collaborative communication performs better than SISO in case of long distances. On the basis of these results it is safe to conclude that collaborative communication in wireless sensor networks using wideband systems improves the life time of nodes in the networks thereby prolonging the network’s life time. PMID:27447489

  19. Spread Spectrum Based Energy Efficient Collaborative Communication in Wireless Sensor Networks.

    PubMed

    Ghani, Anwar; Naqvi, Husnain; Sher, Muhammad; Khan, Muazzam Ali; Khan, Imran; Irshad, Azeem

    2016-01-01

    Wireless sensor networks consist of resource limited devices. Most crucial of these resources is battery life, as in most applications like battle field or volcanic area monitoring, it is often impossible to replace or recharge the power source. This article presents an energy efficient collaborative communication system based on spread spectrum to achieve energy efficiency as well as immunity against jamming, natural interference, noise suppression and universal frequency reuse. Performance of the proposed system is evaluated using the received signal power, bit error rate (BER) and energy consumption. The results show a direct proportionality between the power gain and the number of collaborative nodes as well as BER and signal-to-noise ratio (Eb/N0). The analytical and simulation results of the proposed system are compared with SISO system. The comparison reveals that SISO perform better than collaborative communication in case of small distances whereas collaborative communication performs better than SISO in case of long distances. On the basis of these results it is safe to conclude that collaborative communication in wireless sensor networks using wideband systems improves the life time of nodes in the networks thereby prolonging the network's life time. PMID:27447489

  20. Impact of network structure on the capacity of wireless multihop ad hoc communication

    NASA Astrophysics Data System (ADS)

    Krause, Wolfram; Glauche, Ingmar; Sollacher, Rudolf; Greiner, Martin

    2004-07-01

    As a representative of a complex technological system, the so-called wireless multihop ad hoc communication networks are discussed. They represent an infrastructure-less generalization of todays wireless cellular phone networks. Lacking a central control authority, the ad hoc nodes have to coordinate themselves such that the overall network performs in an optimal way. A performance indicator is the end-to-end throughput capacity. Various models, generating differing ad hoc network structure via differing transmission power assignments, are constructed and characterized. They serve as input for a generic data traffic simulation as well as some semi-analytic estimations. The latter reveal that due to the most-critical-node effect the end-to-end throughput capacity sensitively depends on the underlying network structure, resulting in differing scaling laws with respect to network size.

  1. Complexity analysis and control in joint channel protection system for wireless video communications

    NASA Astrophysics Data System (ADS)

    Jin, Xin; Zhu, Guangxi

    2007-02-01

    In wireless communications, channel coding and error control are essential to protect the video data from wireless interference. The power it consumed, which is determined by the protection method it used, will directly affect the system performance especially on the decoding side. In this paper, a channel coding and error control system, called joint channel protection (JCP) system here, is proposed as an improvement of the hybrid automatic repeat request (HARQ) system to integrate the complexity controllability. The complexity models of the encoder and decoder are established based on theoretical analysis and statistical data retrieval using the time complexity concept, and the relative variation in the computational complexity is carefully studied to provide a proportional variation reference for complexity control. Based on the models, strategies are designed to control the system complexity by adjusting the packet length, iterative decoding times and retransmission ratio according to the decoding quality and complexity level.

  2. SHER: A Colored Petri Net Based Random Mobility Model for Wireless Communications

    PubMed Central

    Khan, Naeem Akhtar; Ahmad, Farooq; Khan, Sher Afzal

    2015-01-01

    In wireless network research, simulation is the most imperative technique to investigate the network’s behavior and validation. Wireless networks typically consist of mobile hosts; therefore, the degree of validation is influenced by the underlying mobility model, and synthetic models are implemented in simulators because real life traces are not widely available. In wireless communications, mobility is an integral part while the key role of a mobility model is to mimic the real life traveling patterns to study. The performance of routing protocols and mobility management strategies e.g. paging, registration and handoff is highly dependent to the selected mobility model. In this paper, we devise and evaluate the Show Home and Exclusive Regions (SHER), a novel two-dimensional (2-D) Colored Petri net (CPN) based formal random mobility model, which exhibits sociological behavior of a user. The model captures hotspots where a user frequently visits and spends time. Our solution eliminates six key issues of the random mobility models, i.e., sudden stops, memoryless movements, border effect, temporal dependency of velocity, pause time dependency, and speed decay in a single model. The proposed model is able to predict the future location of a mobile user and ultimately improves the performance of wireless communication networks. The model follows a uniform nodal distribution and is a mini simulator, which exhibits interesting mobility patterns. The model is also helpful to those who are not familiar with the formal modeling, and users can extract meaningful information with a single mouse-click. It is noteworthy that capturing dynamic mobility patterns through CPN is the most challenging and virulent activity of the presented research. Statistical and reachability analysis techniques are presented to elucidate and validate the performance of our proposed mobility model. The state space methods allow us to algorithmically derive the system behavior and rectify the

  3. SHER: a colored petri net based random mobility model for wireless communications.

    PubMed

    Khan, Naeem Akhtar; Ahmad, Farooq; Khan, Sher Afzal

    2015-01-01

    In wireless network research, simulation is the most imperative technique to investigate the network's behavior and validation. Wireless networks typically consist of mobile hosts; therefore, the degree of validation is influenced by the underlying mobility model, and synthetic models are implemented in simulators because real life traces are not widely available. In wireless communications, mobility is an integral part while the key role of a mobility model is to mimic the real life traveling patterns to study. The performance of routing protocols and mobility management strategies e.g. paging, registration and handoff is highly dependent to the selected mobility model. In this paper, we devise and evaluate the Show Home and Exclusive Regions (SHER), a novel two-dimensional (2-D) Colored Petri net (CPN) based formal random mobility model, which exhibits sociological behavior of a user. The model captures hotspots where a user frequently visits and spends time. Our solution eliminates six key issues of the random mobility models, i.e., sudden stops, memoryless movements, border effect, temporal dependency of velocity, pause time dependency, and speed decay in a single model. The proposed model is able to predict the future location of a mobile user and ultimately improves the performance of wireless communication networks. The model follows a uniform nodal distribution and is a mini simulator, which exhibits interesting mobility patterns. The model is also helpful to those who are not familiar with the formal modeling, and users can extract meaningful information with a single mouse-click. It is noteworthy that capturing dynamic mobility patterns through CPN is the most challenging and virulent activity of the presented research. Statistical and reachability analysis techniques are presented to elucidate and validate the performance of our proposed mobility model. The state space methods allow us to algorithmically derive the system behavior and rectify the errors

  4. Reducing interferences in wireless communication systems by mobile agents with recurrent neural networks-based adaptive channel equalization

    NASA Astrophysics Data System (ADS)

    Beritelli, Francesco; Capizzi, Giacomo; Lo Sciuto, Grazia; Napoli, Christian; Tramontana, Emiliano; Woźniak, Marcin

    2015-09-01

    Solving channel equalization problem in communication systems is based on adaptive filtering algorithms. Today, Mobile Agents (MAs) with Recurrent Neural Networks (RNNs) can be also adopted for effective interference reduction in modern wireless communication systems (WCSs). In this paper MAs with RNNs are proposed as novel computing algorithms for reducing interferences in WCSs performing an adaptive channel equalization. The method to provide it is so called MAs-RNNs. We perform the implementation of this new paradigm for interferences reduction. Simulations results and evaluations demonstrates the effectiveness of this approach and as better transmission performance in wireless communication network can be achieved by using the MAs-RNNs based adaptive filtering algorithm.

  5. Exposure Knowledge and Perception of Wireless Communication Technologies.

    PubMed

    Freudenstein, Frederik; Correia, Luis M; Oliveira, Carla; Sebastião, Daniel; Wiedemann, Peter M

    2015-11-01

    The presented survey investigates risk and exposure perceptions of radio frequency electromagnetic fields (RF EMF) associated with base stations, mobile phones and other sources, the key issue being the interaction between both sets of perceptions. The study is based on a cross-sectional design, and conducted with an online sample of 838 citizens from Portugal. The results indicate that respondents' intuitive exposure perception differs from the actual exposure levels. Furthermore, exposure and risk perceptions are found to be highly correlated. Respondents' beliefs about exposure factors, which might influence possible health risks, is appropriate. A regression analysis between exposure characteristics, as predictor variables, and RF EMF risk perception, as the response variable, indicates that people seem to use simple heuristics to form their perceptions. What is bigger, more frequent and longer lasting is seen as riskier. Moreover, the quality of exposure knowledge is not an indicator for amplified EMF risk perception. These findings show that exposure perception is key to future risk communication. PMID:26561826

  6. Exposure Knowledge and Perception of Wireless Communication Technologies

    PubMed Central

    Freudenstein, Frederik; Correia, Luis M.; Oliveira, Carla; Sebastião, Daniel; Wiedemann, Peter M.

    2015-01-01

    The presented survey investigates risk and exposure perceptions of radio frequency electromagnetic fields (RF EMF) associated with base stations, mobile phones and other sources, the key issue being the interaction between both sets of perceptions. The study is based on a cross-sectional design, and conducted with an online sample of 838 citizens from Portugal. The results indicate that respondents’ intuitive exposure perception differs from the actual exposure levels. Furthermore, exposure and risk perceptions are found to be highly correlated. Respondents’ beliefs  about exposure factors, which might influence possible health risks, is appropriate. A regression analysis between exposure characteristics, as predictor variables, and RF EMF risk perception, as the response variable, indicates that people seem to use simple heuristics to form their perceptions. What is bigger, more frequent and longer lasting is seen as riskier. Moreover, the quality of exposure knowledge is not an indicator for amplified EMF risk perception. These findings show that exposure perception is key to future risk communication. PMID:26561826

  7. Multi-channel access technology based on wavelength division multiplexing in wireless UV communication mesh network

    NASA Astrophysics Data System (ADS)

    Zhao, Tai-fei; Zhang, Ai-li; Xue, Rong-li

    2013-05-01

    In this paper, the multi-channel access technology of wavelength division multiplexing (WDM) in the wireless ultraviolet (UV) scattering communication is studied. A multi-interface and multi-channel device is deployed in each UV transceiver node. The band-pass filter is configured in the receiving node so as to realize the multi-channel access by use of the UV WDM technology. Both the UV communication node model and the UV channel model are established. Three types of UV no-line-of-sight (NLOS) multi-channel communications are simulated in the mesh topologies with NS2. The results show that the UV multi-channel access technology can increase network throughput effectively with using WDM.

  8. Cooperative MIMO communication at wireless sensor network: an error correcting code approach.

    PubMed

    Islam, Mohammad Rakibul; Han, Young Shin

    2011-01-01

    Cooperative communication in wireless sensor network (WSN) explores the energy efficient wireless communication schemes between multiple sensors and data gathering node (DGN) by exploiting multiple input multiple output (MIMO) and multiple input single output (MISO) configurations. In this paper, an energy efficient cooperative MIMO (C-MIMO) technique is proposed where low density parity check (LDPC) code is used as an error correcting code. The rate of LDPC code is varied by varying the length of message and parity bits. Simulation results show that the cooperative communication scheme outperforms SISO scheme in the presence of LDPC code. LDPC codes with different code rates are compared using bit error rate (BER) analysis. BER is also analyzed under different Nakagami fading scenario. Energy efficiencies are compared for different targeted probability of bit error p(b). It is observed that C-MIMO performs more efficiently when the targeted p(b) is smaller. Also the lower encoding rate for LDPC code offers better error characteristics. PMID:22163732

  9. Ultra-wideband miniaturized microstrip patch antennas for wireless communications: Design guidelines and modeling

    NASA Astrophysics Data System (ADS)

    Dandu, Varun Kumar

    The number of wireless communication applications continue to increase steadily, leading to competition for currently allocated frequency bands. Capacity issues in form of data rate and latency have always been a bottleneck for broadband wireless-communication usage. New communication systems like ultra-wideband (UWB) require larger bandwidth than what is normally utilized with traditional antenna techniques. The interest for compact consumer electronics is growing in the meantime, creating a demand on efficient and low profile antennas which can be integrated on a printed circuit board. The main objective of this thesis is to study, design, analyze and implement UWB low profile microstrip patch antenna that satisfy UWB technology requirements. Some methods to extend the bandwidth and other antenna parameters associated with wideband usages are studied. Several techniques are used for optimal UWB bandwidth performance of the UWB microstrip patch antenna. The performance parameters such as VSWR, Gain and radiation pattern of the UWB microstrip patch antenna is extensively investigated with simulations using FEKO. A set of simple design guidelines is proposed to provide approximate rules that result in optimum "first-pass" designs of probe-fed, miniaturized, low profile, microstrip UWB antennas using different bandwidth-enhancement techniques to satisfy UWB bandwidth that require minimal tuning.

  10. Optical Wireless Communication system for particle detectors in high energy physics

    NASA Astrophysics Data System (ADS)

    Ali, W.; Corsini, R.; Ciaramella, E.; Dell`Orso, R.; Messineo, A.; Palla, F.

    2016-07-01

    Optical Wireless Communication (OWC) system for particles detector can be a viable solution for reducing the complexity of the optical fibre network used to extract the data from the detector. In this work we present the initial study of the tolerance to misalignment for the OWC system under investigation. We observed that using collimators of beam waist from 0.35 mm to 3.5 mm we can obtain tolerance in range from ± 0.25 mm to ± 0.8 mm. We also observed using ray trace simulation that both transmitting power and tolerance can be improved by using optimized lens at the receiver having VCSEL as transmitting source.

  11. Investigation on an RFID planar coil for a wireless communicative aortic stent

    NASA Astrophysics Data System (ADS)

    Talleb, Hakeim; Faci, Salim; Lautru, David; Hanna, Victor Fouad; Wiart, Joe

    2013-05-01

    This paper presents an investigation on a potential biomedical RFID planar coil operating at 13.56 MHz for measuring the blood pressure level, mounted inside an abdominal aortic aneurysm. The results show that a wireless communication is achieved in a perimeter of 60 cm, while respecting the ISO 15693 standard for vicinity contactless cards. Measurement and electromagnetic simulation results show that the inductive coupling is deteriorating if the planar coil is in direct contact with water without correctly encapsulating this coil. An electric model is given for our proposed RFID planar coil immersed in water.

  12. Numerical models and experiment of air flow in a simulation box for optical wireless communications

    NASA Astrophysics Data System (ADS)

    Latal, Jan; Hajek, Lukas; Bojko, Marian; Vitasek, Jan; Koudelka, Petr; Kepak, Stanislav; Vanderka, Ales; Vasinek, Vladimir

    2016-03-01

    In this article, the authors focused on real measurements of mechanical turbulence generated by ventilators in the simulation box for Optical Wireless Communications. The mechanical turbulences disturb the optical beam that propagates along the central axis of the simulation box. The aim of authors is to show the effect of mechanical turbulence on optical beams at different heights in the simulation box. In the Ansys Fluent, we created numerical models which were then compared with real measurements. Authors compared the real and numerical models according to statistical methods.

  13. An Integrated Signaling-Encryption Mechanism to Reduce Error Propagation in Wireless Communications: Performance Analyses

    SciTech Connect

    Olama, Mohammed M; Matalgah, Mustafa M; Bobrek, Miljko

    2015-01-01

    Traditional encryption techniques require packet overhead, produce processing time delay, and suffer from severe quality of service deterioration due to fades and interference in wireless channels. These issues reduce the effective transmission data rate (throughput) considerably in wireless communications, where data rate with limited bandwidth is the main constraint. In this paper, performance evaluation analyses are conducted for an integrated signaling-encryption mechanism that is secure and enables improved throughput and probability of bit-error in wireless channels. This mechanism eliminates the drawbacks stated herein by encrypting only a small portion of an entire transmitted frame, while the rest is not subject to traditional encryption but goes through a signaling process (designed transformation) with the plaintext of the portion selected for encryption. We also propose to incorporate error correction coding solely on the small encrypted portion of the data to drastically improve the overall bit-error rate performance while not noticeably increasing the required bit-rate. We focus on validating the signaling-encryption mechanism utilizing Hamming and convolutional error correction coding by conducting an end-to-end system-level simulation-based study. The average probability of bit-error and throughput of the encryption mechanism are evaluated over standard Gaussian and Rayleigh fading-type channels and compared to the ones of the conventional advanced encryption standard (AES).

  14. Using the combination refraction-reflection solid to design omni-directional light source used in underwater wireless optical communication

    NASA Astrophysics Data System (ADS)

    Rao, Jionghui; Yao, Wenming; Wen, Linqiang

    2015-10-01

    Underwater wireless optical communication is a communication technology which uses laser as an information carrier and transmits data through water. Underwater wireless optical communication has some good features such as broader bandwidth, high transmission rate, better security, anti—interference performance. Therefore, it is promising to be widely used in the civil and military communication domains. It is also suitable for high-speed, short-range communication between underwater mobile vehicles. This paper presents a design approach of omni-directional light source used in underwater wireless optical communication, using TRACEPRO simulation tool to help design a combination solid composed of the lens, conical reflector and parabolic reflector, and using the modulated DPSS green laser in the transmitter module to output the laser beam in small divergence angles, after expanded by the combination refraction-reflection solid, the angle turns into a space divergence angle of 2π, achieving the omni-directional light source of hemisphere space, and test in the air and underwater, the result shows that the effect is fine. This paper analyzes the experimental test in the air and water, in order to make further improvement of the uniformity of light distribution, we optimize the reflector surface parameters of combination refraction-reflection solid and test in the air and water. The result shows that omni-directional light source used in underwater wireless optical communication optimized could achieve the uniformity of light distribution of underwater space divergence angle of 2π. Omni-directional light source used in underwater wireless optical communication designed in this paper has the characteristics of small size and uniformity of light distribution, it is suitable for application between UUVs, AUVs, Swimmer Delivery Vehicles (SDVs) and other underwater vehicle fleet, it realizes point-to-multipoint communications.

  15. Design and implementation of omni-directional light source and receiving system used in underwater wireless optical communication

    NASA Astrophysics Data System (ADS)

    Rao, Jionghui; Yao, Wenming; Chen, Nannan

    2013-08-01

    Underwater wireless optical communication is a communication mode which uses light as an information carrier and water as transmission medium. As a result of the inherent characteristics of the light waves, underwater wireless optical communication has the advantages of high transmission rate, good security, and strong anti-interference ability. It is suitable for high-speed, short-range communication between underwater mobile vehicles. Underwater optical wireless communication system designed in this paper is composed of the omni-directional communication light source and the receiving system. In the omni-directional communication light source, the laser beams with small divergence angle of 532nm wavelength produced by modulated laser are expanded through a combination refraction-reflection solid and then obtain more than 2π space divergence angle. The paper use TRACEPRO simulation tool to help design a combination solid composed of the lens, conical reflector and parabolic reflector, and test in the air and underwater, the result shows that the effect is fine. Unlike in the air, light attenuation is heavy in the water and a large range of variations in light intensity at different distances appear during underwater optical communication. In order to overcome this problem, the paper use a small photomultiplier as the detection device, design the receiving system using the automatic gain control technique. Underwater wireless optical communication system designed in this paper has the characteristics of small size, low power dissipation and the omni-directional communication function, it is suitable for application in the UUV, AUV, Swimmer Delivery Vehicle (SDV) and other underwater mobile platform, it realizes point-to-point communications and point-to-multipoint communications.

  16. ICSW2AN : An Inter-vehicle Communication System Using Mobile Access Point over Wireless Wide Area Networks

    NASA Astrophysics Data System (ADS)

    Byun, Tae-Young

    This paper presents a prototype of inter-vehicle communication system using mobile access point that internetworks wired or wireless LAN and wireless WAN anywhere. Implemented mobile access point can be equipped with various wireless WAN interfaces such as WCDMA and HSDPA. Mobile access point in the IP mechanism has to process connection setup procedure to one wireless WAN. To show the applicability of the mobile access point to inter-vehicle communication, a simplified V2I2V-based car communication system called ICSW2AN is implemented to evaluate major performance metrics by road test. In addition, results of road test for traffic information service are investigated in view of RTT, latency and server processing time. The experimental result indicates that V2I2V-based car communication system sufficiently can provide time-tolerant traffic information to moving vehicles while more than two mobile devices in restricted spaces such as car, train and ship access wireless Internet simultaneously.

  17. Ultrahigh-Bitrate Wireless Data Communications via THz-Links; Possibilities and Challenges

    NASA Astrophysics Data System (ADS)

    Schneider, Thomas

    2015-02-01

    The data rate in the communication networks increases by a two number digit every year. Even today's mobile, wireless devices offer a large number of high-bitrate data services reaching from entertainment over information to communication. However, for the so called last-mile problem, for the connection of the network with remote cellular base stations and for other wireless links ultrahigh-bitrate connections are required. Another important application of ultrahigh-bitrate wireless links is the very fast rebuilding of a network infrastructure after natural disasters like tsunamis, hurricanes and blizzards. Contrary to optical links, carrier waves in the submillimeter-wave, or THz-region of the electromagnetic spectrum offer a high capacity and reliability even under worst weather conditions like a strong rain or dense fog. The THz-range has a large bandwidth so that even with simple modulation formats a quite high bitrate can be transmitted. However, ultrahigh bitrates require spectrally efficient modulation formats and these formats require THz-sources with a very high quality, i.e. low phase noise and narrow linewidth. Here an overview of the possibilities and challenges for ultrahigh bitrate transmission and the generation of high-quality THz-waves is given and a method for the generation of very stable and precise millimeter and THz waves is presented. In first proof of concept experiments a linewidth of < 1 Hz and a phase noise of < -130 dBc/Hz at an offset of 10 kHz from the carrier was measured in the microwave range.

  18. Novel Wireless-Communicating Textiles Made from Multi-Material and Minimally-Invasive Fibers

    PubMed Central

    Gorgutsa, Stepan; Bélanger-Garnier, Victor; Ung, Bora; Viens, Jeff; Gosselin, Benoit; LaRochelle, Sophie; Messaddeq, Younes

    2014-01-01

    The ability to integrate multiple materials into miniaturized fiber structures enables the realization of novel biomedical textile devices with higher-level functionalities and minimally-invasive attributes. In this work, we present novel textile fabrics integrating unobtrusive multi-material fibers that communicate through 2.4 GHz wireless networks with excellent signal quality. The conductor elements of the textiles are embedded within the fibers themselves, providing electrical and chemical shielding against the environment, while preserving the mechanical and cosmetic properties of the garments. These multi-material fibers combine insulating and conducting materials into a well-defined geometry, and represent a cost-effective and minimally-invasive approach to sensor fabrics and bio-sensing textiles connected in real time to mobile communications infrastructures, suitable for a variety of health and life science applications. PMID:25325335

  19. Automated alignment system for optical wireless communication systems using image recognition.

    PubMed

    Brandl, Paul; Weiss, Alexander; Zimmermann, Horst

    2014-07-01

    In this Letter, we describe the realization of a tracked line-of-sight optical wireless communication system for indoor data distribution. We built a laser-based transmitter with adaptive focus and ray steering by a microelectromechanical systems mirror. To execute the alignment procedure, we used a CMOS image sensor at the transmitter side and developed an algorithm for image recognition to localize the receiver's position. The receiver is based on a self-developed optoelectronic integrated chip with low requirements on the receiver optics to make the system economically attractive. With this system, we were able to set up the communication link automatically without any back channel and to perform error-free (bit error rate <10⁻⁹) data transmission over a distance of 3.5 m with a data rate of 3 Gbit/s. PMID:24978803

  20. Average capacity for optical wireless communication systems over exponentiated Weibull distribution non-Kolmogorov turbulent channels.

    PubMed

    Cheng, Mingjian; Zhang, Yixin; Gao, Jie; Wang, Fei; Zhao, Fengsheng

    2014-06-20

    We model the average channel capacity of optical wireless communication systems for cases of weak to strong turbulence channels, using the exponentiation Weibull distribution model. The joint effects of the beam wander and spread, pointing errors, atmospheric attenuation, and the spectral index of non-Kolmogorov turbulence on system performance are included. Our results show that the average capacity decreases steeply as the propagation length L changes from 0 to 200 m and decreases slowly down or tends to a stable value as the propagation length L is greater than 200 m. In the weak turbulence region, by increasing the detection aperture, we can improve the average channel capacity and the atmospheric visibility as an important issue affecting the average channel capacity. In the strong turbulence region, the increase of the radius of the detection aperture cannot reduce the effects of the atmospheric turbulence on the average channel capacity, and the effect of atmospheric visibility on the channel information capacity can be ignored. The effect of the spectral power exponent on the average channel capacity in the strong turbulence region is higher than weak turbulence region. Irrespective of the details determining the turbulent channel, we can say that pointing errors have a significant effect on the average channel capacity of optical wireless communication systems in turbulence channels. PMID:24979434

  1. An Energy-Harvesting Wireless-Interface SoC for Short-Range Data Communication

    NASA Astrophysics Data System (ADS)

    Mikami, Shinji; Matsuno, Tetsuro; Miyama, Masayuki; Kawaguchi, Hiroshi; Yoshimoto, Masahiko; Ono, Hiroaki

    This paper describes design and verification of a wireless-interface SoC (system-on-a-chip) for a wireless battery-less mouse with short-range data-communication capability. The SoC comprises an RF transmitter and microcontroller. The SoC, which is powered by an electric generator that exploits gyration energy by dragging the mouse, was fabricated using a TSMC 0.18-um CMOS process. The features of the SoC are the adoption of a simple FSK modulation scheme, single-end configuration on the RF transmitter, and specific microcontroller design for mouse operation. We verified that the RF transmitter can make data communication within a 1-m range at 2.17 mW, and the microcontroller consumes 0.03 mW at 1 MHz, which exhibits that the total power consumption is 2.2 mW. This is sufficiently low for the SoC to operate with energy harvesting.

  2. Reliable and energy-efficient communications for wireless biomedical implant systems.

    PubMed

    Ntouni, Georgia D; Lioumpas, Athanasios S; Nikita, Konstantina S

    2014-11-01

    Implant devices are used to measure biological parameters and transmit their results to remote off-body devices. As implants are characterized by strict requirements on size, reliability, and power consumption, applying the concept of cooperative communications to wireless body area networks offers several benefits. In this paper, we aim to minimize the power consumption of the implant device by utilizing on-body wearable devices, while providing the necessary reliability in terms of outage probability and bit error rate. Taking into account realistic power considerations and wireless propagation environments based on the IEEE P802.l5 channel model, an exact theoretical analysis is conducted for evaluating several communication scenarios with respect to the position of the wearable device and the motion of the human body. The derived closed-form expressions are employed toward minimizing the required transmission power, subject to a minimum quality-of-service requirement. In this way, the complexity and power consumption are transferred from the implant device to the on-body relay, which is an efficient approach since they can be easily replaced, in contrast to the in-body implants. PMID:25375682

  3. A Multi-Vehicles, Wireless Testbed for Networked Control, Communications and Computing

    NASA Astrophysics Data System (ADS)

    Murray, Richard; Doyle, John; Effros, Michelle; Hickey, Jason; Low, Steven

    2002-03-01

    We have constructed a testbed consisting of 4 mobile vehicles (with 4 additional vehicles being completed), each with embedded computing and communications capability for use in testing new approaches for command and control across dynamic networks. The system is being used or is planned to be used for testing of a variety of communications-related technologies, including distributed command and control algorithms, dynamically reconfigurable network topologies, source coding for real-time transmission of data in lossy environments, and multi-network communications. A unique feature of the testbed is the use of vehicles that have second order dynamics. Requiring real-time feedback algorithms to stabilize the system while performing cooperative tasks. The testbed was constructed in the Caltech Vehicles Laboratory and consists of individual vehicles with PC-based computation and controls, and multiple communications devices (802.11 wireless Ethernet, Bluetooth, and infrared). The vehicles are freely moving, wheeled platforms propelled by high performance dotted fairs. The room contains an access points for an 802.11 network, overhead visual sensing (to allow emulation of CI'S signal processing), a centralized computer for emulating certain distributed computations, and network gateways to control and manipulate communications traffic.

  4. Selection of bi-level image compression method for reduction of communication energy in wireless visual sensor networks

    NASA Astrophysics Data System (ADS)

    Khursheed, Khursheed; Imran, Muhammad; Ahmad, Naeem; O'Nils, Mattias

    2012-06-01

    Wireless Visual Sensor Network (WVSN) is an emerging field which combines image sensor, on board computation unit, communication component and energy source. Compared to the traditional wireless sensor network, which operates on one dimensional data, such as temperature, pressure values etc., WVSN operates on two dimensional data (images) which requires higher processing power and communication bandwidth. Normally, WVSNs are deployed in areas where installation of wired solutions is not feasible. The energy budget in these networks is limited to the batteries, because of the wireless nature of the application. Due to the limited availability of energy, the processing at Visual Sensor Nodes (VSN) and communication from VSN to server should consume as low energy as possible. Transmission of raw images wirelessly consumes a lot of energy and requires higher communication bandwidth. Data compression methods reduce data efficiently and hence will be effective in reducing communication cost in WVSN. In this paper, we have compared the compression efficiency and complexity of six well known bi-level image compression methods. The focus is to determine the compression algorithms which can efficiently compress bi-level images and their computational complexity is suitable for computational platform used in WVSNs. These results can be used as a road map for selection of compression methods for different sets of constraints in WVSN.

  5. Sensing Traffic Density Combining V2V and V2I Wireless Communications

    PubMed Central

    Sanguesa, Julio A.; Barrachina, Javier; Fogue, Manuel; Garrido, Piedad; Martinez, Francisco J.; Cano, Juan-Carlos; Calafate, Carlos T.; Manzoni, Pietro

    2015-01-01

    Wireless technologies are making the development of new applications and services in vehicular environments possible since they enable mobile communication between vehicles (V2V), as well as communication between vehicles and infrastructure nodes (V2I). Usually, V2V communications are dedicated to the transmission of small messages mainly focused on improving traffic safety. Instead, V2I communications allow users to access the Internet and benefit from higher level applications. The combination of both V2V and V2I, known as V2X communications, can increase the benefits even further, thereby making intelligent transportation systems (ITS) a reality. In this paper, we introduce V2X-d, a novel architecture specially designed to estimate traffic density on the road. In particular, V2X-d exploits the combination of V2V and V2I communications. Our approach is based on the information gathered by sensors (i.e., vehicles and road side units (RSUs)) and the characteristics of the roadmap topology to accurately make an estimation of the instant vehicle density. The combination of both mechanisms improves the accuracy and coverage area of the data gathered, while increasing the robustness and fault tolerance of the overall approach, e.g., using the information offered by V2V communications to provide additional density information in areas where RSUs are scarce or malfunctioning. By using our collaborative sensing scheme, future ITS solutions will be able to establish adequate dissemination protocols or to apply more efficient traffic congestion reduction policies, since they will be aware of the instantaneous density of vehicles. PMID:26694405

  6. Sensing Traffic Density Combining V2V and V2I Wireless Communications.

    PubMed

    Sanguesa, Julio A; Barrachina, Javier; Fogue, Manuel; Garrido, Piedad; Martinez, Francisco J; Cano, Juan-Carlos; Calafate, Carlos T; Manzoni, Pietro

    2015-01-01

    Wireless technologies are making the development of new applications and services in vehicular environments possible since they enable mobile communication between vehicles (V2V), as well as communication between vehicles and infrastructure nodes (V2I). Usually, V2V communications are dedicated to the transmission of small messages mainly focused on improving traffic safety. Instead, V2I communications allow users to access the Internet and benefit from higher level applications. The combination of both V2V and V2I, known as V2X communications, can increase the benefits even further, thereby making intelligent transportation systems (ITS) a reality. In this paper, we introduce V2X-d, a novel architecture specially designed to estimate traffic density on the road. In particular, V2X-d exploits the combination of V2V and V2I communications. Our approach is based on the information gathered by sensors (i.e., vehicles and road side units (RSUs)) and the characteristics of the roadmap topology to accurately make an estimation of the instant vehicle density. The combination of both mechanisms improves the accuracy and coverage area of the data gathered, while increasing the robustness and fault tolerance of the overall approach, e.g., using the information offered by V2V communications to provide additional density information in areas where RSUs are scarce or malfunctioning. By using our collaborative sensing scheme, future ITS solutions will be able to establish adequate dissemination protocols or to apply more efficient traffic congestion reduction policies, since they will be aware of the instantaneous density of vehicles. PMID:26694405

  7. A hybrid MAC protocol design for energy-efficient very-high-throughput millimeter wave, wireless sensor communication networks

    NASA Astrophysics Data System (ADS)

    Jian, Wei; Estevez, Claudio; Chowdhury, Arshad; Jia, Zhensheng; Wang, Jianxin; Yu, Jianguo; Chang, Gee-Kung

    2010-12-01

    This paper presents an energy-efficient Medium Access Control (MAC) protocol for very-high-throughput millimeter-wave (mm-wave) wireless sensor communication networks (VHT-MSCNs) based on hybrid multiple access techniques of frequency division multiplexing access (FDMA) and time division multiplexing access (TDMA). An energy-efficient Superframe for wireless sensor communication network employing directional mm-wave wireless access technologies is proposed for systems that require very high throughput, such as high definition video signals, for sensing, processing, transmitting, and actuating functions. Energy consumption modeling for each network element and comparisons among various multi-access technologies in term of power and MAC layer operations are investigated for evaluating the energy-efficient improvement of proposed MAC protocol.

  8. Optical wireless communication through fog in the presence of pointing errors

    NASA Astrophysics Data System (ADS)

    Kedar, Debbie; Arnon, Shlomi

    2003-08-01

    Terrestrial optical wireless communication (OWC) is emerging as a promising technology, which makes connectivity possible between high-rise buildings and metropolitan and intercity communication infrastructures. A light beam carries the information, which facilitates extremely high data rates. However, strict alignment between the transmitter and the receiver must be maintained at all times, and a pointing error can result in a total severance of the communication link. In addition, the presence of fog and haze in the propagation channel hampers OWC as the small water droplets scatter the propagating light. This causes attenuation due to the resultant spatial, angular, and temporal spread of the light signal. Furthermore, the ensuing low visibility may impede the operation of the tracking and pointing system so that pointing errors occur. We develop a model of light transmission through fogs of different optical densities and types using Monte Carlo simulations. Based on this model, the performance of OWC in fogs is evaluated at different wavelengths. The handicap of a transceiver pointing error is added to the model, and the paradoxically advantageous aspects of the transmission medium are exposed. The concept of a variable field of view receiver for narrow-beam OWC is studied, and the possibility of thus enhancing communication system performance through fog in an inexpensive and simple way is indicated.

  9. DXBC: a long distance wireless broadband communication system for coastal maritime surveillance applications

    NASA Astrophysics Data System (ADS)

    Vastianos, George E.; Argyreas, Nick D.; Xilouris, Chris K.; Thomopoulos, Stelios C. A.

    2015-05-01

    The field of Homeland Security focuses on the air, land, and sea borders surveillance in order to prevent illegal activities while facilitating lawful travel and trade. The achievement of this goal requires collaboration of complex decentralized systems and services, and transfer of huge amount of information between the remote surveillance areas and the command & control centers. It becomes obvious that the effectiveness of the provided security depends highly on the available communication capabilities between the interconnected areas. Although nowadays the broadband communication between remote places is presumed easy because of the extensive infrastructure inside residential areas, it becomes a real challenge when the required information should be acquired from locations where no infrastructure is available such as mountain or sea areas. The Integrated Systems Lab of NCSR Demokritos within the PERSEUS FP7- SEC-2011-261748 project has developed a wireless broadband telecommunication system that combines different communication channels from subGHz to microwave frequencies and provides secure IP connectivity between sea surveillance vessels and the Command and Control Centers (C3). The system was deployed in Fast Patrol Boats of the Hellenic Coast Guard that are used for maritime surveillance in sea boarders and tested successfully in two demonstration exercises for irregular migration and smuggling scenarios in the Aegean Archipelagos. This paper describes in detail the system architecture in terms of hardware and software and the evaluation measurements of the system communication capabilities.

  10. Development of wireless communication system in real-time internal radiation dose measurement system using magnetic field

    NASA Astrophysics Data System (ADS)

    Sato, Fumihiro; Shinohe, Kohta; Takura, Tetsuya; Matsuki, Hidetoshi; Yamada, Syogo; Sato, Tadakuni

    2009-04-01

    In radiation therapy, excessive radiation occurs because the actual delivered dose to the tumor is unknown. To overcome this problem, we need a system in which the delivered dose is measured inside the body, and the dose data are transmitted from the inside to the outside of the body. In this study, a wireless communication system, using magnetic fields was studied, and an internal circuit for obtaining radiation dose data from an x-ray detector was examined. As a result, a communication distance of 200 mm was obtained. An internal circuit was developed, and a signal transmission experiment was performed using the wireless communication system. As a result, the radiation dose data from an x-ray detector was transmitted over a communication distance of 200 mm, and the delivered dose was determined from the received signal.