Sample records for mobile communications gsm

  1. Interference of GSM mobile phones with communication between Cardiac Rhythm Management devices and programmers: A combined in vivo and in vitro study.

    PubMed

    Huang, Dong; Dong, Zhi-Feng; Chen, Yan; Wang, Fa-Bin; Wei, Zhi; Zhao, Wen-Bin; Li, Shuai; Liu, Ming-Ya; Zhu, Wei; Wei, Meng; Li, Jing-Bo

    2015-05-01

    To investigate interference, and how to avoid it, by high-frequency electromagnetic fields (EMFs) of Global System for Mobile Communications (GSM) mobile phone with communication between cardiac rhythm management devices (CRMs) and programmers, a combined in vivo and in vitro testing was conducted. During in vivo testing, GSM mobile phones interfered with CRM-programmer communication in 33 of 65 subjects tested (50.8%). Losing ventricle sensing was representative in this study. In terms of clinical symptoms, only 4 subjects (0.6%) felt dizzy during testing. CRM-programmer communication recovered upon termination of mobile phone communication. During in vitro testing, electromagnetic interference by high-frequency (700-950?MHz) EMFs reproducibly occurred in duplicate testing in 18 of 20 CRMs (90%). During each interference, the pacing pulse signal on the programmer would suddenly disappear while the synchronous signal was normal on the amplifier-oscilloscope. Simulation analysis showed that interference by radiofrequency emitting devices with CRM-programmer communication may be attributed to factors including materials, excitation source distance, and implant depth. Results suggested that patients implanted with CRMs should not be restricted from using GSM mobile phones; however, CRMs should be kept away from high-frequency EMFs of GSM mobile phone during programming. Bioelectromagnetics. 36:367-376, 2015. © 2015 Wiley Periodicals, Inc. PMID:25864643

  2. iGSM: VoIP service for mobile networks

    Microsoft Academic Search

    Herman C. H. Rao; Yi-Bing Lin; Sheng-Lin Cho

    2000-01-01

    This article proposes iGSM: a voice-over-IP value-added service for the mobile network. The iGSM service provides user mobility to subscribers, which allows them to use either GSM handsets or H.323 terminals (IP phones or PCs) to access telecommunications services. We describe how the iGSM registration, deregistration, and call delivery procedures can be implemented without modifying the GSM network. We study

  3. GSM MOBILE PHONE IN DISTRIBUTED VIRTUAL INSTRUMENTATION

    Microsoft Academic Search

    W. Winiecki; A. Kuran; R. ?ukaszewski

    Remote, wireless controlling of distributed virtual instrument (DVI) using GSM mobile phones is considered. Interactive WAP service is applied to configure measuring system, to control measurement process and to access to measurement data. The service is based on ASP technology and dynamic databases. National Instruments PC-1200 DAQ card, programmed with LabVIEW, was applied to design a wireless DVI (WDVI).

  4. NFC Mobile Transactions and Authentication Based on GSM Network

    Microsoft Academic Search

    W. Chen; G. P. Hancke; K. E. Mayes; Y. Lien; J.-H. Chiu

    2010-01-01

    This paper describes a mobile payment system for merchant micropayments, which can be build on existing GSM and NFC architecture components. Many mobile payment methods have been proposed, although such methods are intended for peer-to-peer transactions rather than a conventional merchant payment environment. Our proposal leverages the SIM's authentication and identification capabilities and uses GSM cryptographic primitives, which simplifies integration

  5. Integrated GSM\\/WiFi Backhauling over Satellite: Flexible Solution for Emergency Communications

    Microsoft Academic Search

    Eriza Hafid Fazli; Markus Werner; Nicolas Courville; Matteo Berioli; Vincent Boussemart

    2008-01-01

    This paper presents the development of a compact, ruggedized satellite terminal, to be used for communications in emergency situation. The terminal provides GSM coverage in disaster area, where existing communication infrastructure is destroyed or overloaded. It uses GSM backhauling over satellite to transport GSM signalling and data traffic to the core GSM network infrastructure in the disaster-safe area. Additionally, basic

  6. Positioning GSM telephones

    Microsoft Academic Search

    Christopher Drane; Malcolm Macnaughtan; Craig Scott

    1998-01-01

    Due to the FCC requirement that operators of mobile communications networks be able to accurately locate mobile callers requesting emergency assistance via 911 by the year 2001, there has been a lot of activity among cellular and PCS providers to examine cellular positioning options. This article examines positioning solutions for the GSM group of standards. Worldwide deployment of GSM systems

  7. Location Update (GSM Location Update Procedure) Highway Virginia GSM Maryland

    E-print Network

    Ricci, Francesco

    Location Update (GSM Location Update Procedure) Highway Virginia GSM Maryland GSM Mobiles Virginia Location Area Virginia GSM Equipment GSM Databases Maryland Location Area Maryland GSM Equipment Other GSM Mobile GSM Mobile Vienna Cell Virginia BSC Virginia MSC VLR HLR Rockville Cell Bethesda Cell Maryland MSC

  8. LOW COST RECONFIGURABLE HARDWARE ARCHITECTURE FOR SECURE MOBILE COMMUNICATION

    Microsoft Academic Search

    G. Uma Maheswari; B. Venkatramanan; Mothi V. Sabaresan

    Mobile communication is presently used by large number of people and Global System for Mobile Communication (GSM) is the most widely used cellular mobile phone system in the world. In mobile communications, cryptography techniques are used extensively for secure transmission and reception of data. Cryptanalysis has become a challenging task as crypto algorithm becoming stronger with advent of supercomputing power

  9. A high-speed railway mobile communication system based on LTE

    Microsoft Academic Search

    Gao Tingting; Sun Bin

    2010-01-01

    Along with the developments of the high-speed railway, higher and higher technical requirements for the high-speed railway mobile communication system are raised. Since the “Global System for Mobile Communications Railways” (GSM-R) implemented today is based on GSM, the new technology in GSM evolution can be used in the highspeed railway mobile communication system to adapt to the new requirements. This

  10. [A method for transfering physiological data through GSM wireless communication network].

    PubMed

    Guo, Jin-song; Deng, Qin-kai

    2003-01-01

    This article describes a method for transfering physiological data through GSM wireless communication network. The data of heart rate and body temperature are collected by a microcontroller and transmitted through serial ports to the GSM data module, which then transmits the data to a remote terminal through GSM network. This method ensures cheap and stable long-distance data transfer within the coverage of the GSM network. PMID:12527517

  11. Reduced growth of soybean seedlings after exposure to weak microwave radiation from GSM 900 mobile phone and base station.

    PubMed

    Halgamuge, Malka N; Yak, See Kye; Eberhardt, Jacob L

    2015-02-01

    The aim of this work was to study possible effects of environmental radiation pollution on plants. The association between cellular telephone (short duration, higher amplitude) and base station (long duration, very low amplitude) radiation exposure and the growth rate of soybean (Glycine max) seedlings was investigated. Soybean seedlings, pre-grown for 4 days, were exposed in a gigahertz transverse electromagnetic cell for 2?h to global system for mobile communication (GSM) mobile phone pulsed radiation or continuous wave (CW) radiation at 900?MHz with amplitudes of 5.7 and 41?V?m(-1) , and outgrowth was studied one week after exposure. The exposure to higher amplitude (41?V?m(-1)) GSM radiation resulted in diminished outgrowth of the epicotyl. The exposure to lower amplitude (5.7?V?m(-1)) GSM radiation did not influence outgrowth of epicotyl, hypocotyls, or roots. The exposure to higher amplitude CW radiation resulted in reduced outgrowth of the roots whereas lower CW exposure resulted in a reduced outgrowth of the hypocotyl. Soybean seedlings were also exposed for 5 days to an extremely low level of radiation (GSM 900?MHz, 0.56?V?m(-1)) and outgrowth was studied 2 days later. Growth of epicotyl and hypocotyl was found to be reduced, whereas the outgrowth of roots was stimulated. Our findings indicate that the observed effects were significantly dependent on field strength as well as amplitude modulation of the applied field. PMID:25644316

  12. Remote control of an ultrasonic motor by using a GSM mobile phone

    Microsoft Academic Search

    Erdal Bekiroglu; Nihat Daldal

    2005-01-01

    In this study, remote control of an ultrasonic motor has been implemented by using a standard GSM mobile phone. To drive the ultrasonic motor a digitally controlled drive system has been designed. Then a tone decoder circuit and microcontroller have been added between output of a mobile phone and the drive system of the motor. This system is flexible to

  13. GSM Security Using Identity-based Cryptography

    E-print Network

    Agarwal, Animesh; Das, Manik Lal

    2009-01-01

    Current security model in Global System for Mobile Communications (GSM) predominantly use symmetric key cryptography. The rapid advancement of Internet technology facilitates online trading, banking, downloading, emailing using resource-constrained handheld devices such as personal digital assistants and cell phones. However, these applications require more security than the present GSM supports. Consequently, a careful design of GSM security using both symmetric and asymmetric key cryptography would make GSM security more adaptable in security intensive applications. This paper presents a secure and efficient protocol for GSM security using identity based cryptography. The salient features of the proposed protocol are (i) authenticated key exchange; (ii) mutual authentication amongst communicating entities; and (iii) user anonymity. The security analysis of the protocol shows its strength against some known threats observed in conventional GSM security.

  14. Low-profile penta-band monopole antenna for mobile communication applications

    Microsoft Academic Search

    Yu Han; Junhong Wang; Meie Chen; Zhan Zhang

    2011-01-01

    An internal monopole antenna with compact size is proposed in this paper, which can be applied to mobile communications, and its frequency band covers GSM850, GSM900, DCS, PCS, UMTS bands simultaneously. It is comprised of a driven monopole and a coupled loop strip. By inserting a folded slit in the driven rectangular patch, two wide bands are achieved. The antenna

  15. Proposal for the Award of a Contract for the Provision of GSM Mobile Telephone Services

    E-print Network

    2003-01-01

    This document concerns the award of a contract for the provision of GSM mobile telephone services. Following a call for tenders (IT-3121/IT) sent on 11 March 2003 to ten firms in five Member States, CERN had received, by the closing date, two tenders from two firms in one Member State. The Finance Committee is invited to agree to the negotiation of a contract with TDC SWITZERLAND (CH), the lowest bidder, for the provision of GSM mobile telephone services for a period of six years, for a total amount not exceeding 2 308 630 Swiss francs, not subject to revision. The contract will include options for two one-year extensions beyond the initial six-year period. The firm has indicated the following distribution by country of the contract value covered by this adjudication proposal: CH - 100%.

  16. An Intelligent Location Management approaches in GSM Mobile Network

    E-print Network

    Rao, N Mallikharjuna

    2012-01-01

    Location management refers to the problem of updating and searching the current location of mobile nodes in a wireless network. To make it efficient, the sum of update costs of location database must be minimized. Previous work relying on fixed location databases is unable to fully exploit the knowledge of user mobility patterns in the system so as to achieve this minimization. The study presents an intelligent location management approach which has interacts between intelligent information system and knowledge-base technologies, so we can dynamically change the user patterns and reduce the transition between the VLR and HLR. The study provides algorithms are ability to handle location registration and call delivery

  17. GSM solutions for low cost embedded systems for industrial control

    Microsoft Academic Search

    Andrei Drumea; Camelia Popescu; Paul Svasta

    2005-01-01

    Control systems with remote access capabilities become today more and more popular due to their extra advantages - control from distance and possibility to automate (batch processing) different tasks. An off-the-shelf technology for remote access is GSM (Global System for Mobile Communications) and can be easily integrated into embedded systems using modern GSM serial modems. Another trend in control systems

  18. Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors

    PubMed Central

    Mortazavi, SMJ; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, AR

    2014-01-01

    Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students), blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2) while the phone was ringing. For Control- Repeat group (15 students), two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (|?C|) in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P < 0.001, two-tailed test). To the best of our knowledge, this is the first study to assess the electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors. PMID:25505778

  19. Technical and Cost Efficiency of GSM Commercial Call Centers: A Stochastic Frontier Approach

    Microsoft Academic Search

    Samuel Adebayo Oluwadare; Olumide Sunday Adewale

    One of the key areas in which science and technology has had profound impact on the Nigerian economy in recent years, is in the area of Global System for Mobile Communication (GSM). The introduction of GSM into Nigeria in 2001 has opened up a lot of opportunities ranging from ease of communication to commerce, industry, trade and tourism; and employment,

  20. General packet radio service in GSM

    Microsoft Academic Search

    Jain Cai; David J. Goodman

    1997-01-01

    In the Global System for Mobile Communications (GSM) Phase 2+ development, one major activity is to specify the general packet radio service (GPRS). The standardization is expected to be completed at the end of 1997. The purpose of GPRSI like other packet data services, is to efficiently accommodate data sources that are bursty in nature. Another important goal of the

  1. Evolution of Charging and Billing Models for GSM and Future Mobile Internet Services

    Microsoft Academic Search

    John Cushnie; David Hutchison; Huw Oliver

    2000-01-01

    Mobile telephone communications and the Internet are converging and may eventually operate on a common technical platform, using TCP\\/IP networks as the main backbone medium. Mobile telephones are converging to Internet terminals, allowing the user access to email, Web browsing and all the other Internet services currently available from a desktop computer environment. In order to provide improved infrastructure for

  2. Modeling of a GSM-R receiving chain exposed to transient IEMIs

    E-print Network

    Paris-Sud XI, Université de

    Modeling of a GSM-R receiving chain exposed to transient IEMIs Souheir Mili, Virginie Deniau, David and command/control signals will become exchanged over Global System for Mobile communications-Railways (GSMMagnetic Interference (IEMI) threats. In this paper we investigate GSM-R vulnerability to IEMI. These IEMIs consist

  3. Mobile satellite communications

    Microsoft Academic Search

    W. W. Wu; E. F. Miller; W. L. Pritchard; R. L. Pickholtz

    1994-01-01

    The paper presents an up-to-date overview as well as new results on mobile satellite communications. Specifically, the following subjects are addressed: worldwide activities; satellite orbits; multiple access techniques; Novstar global positioning system; economic and regulatory issues; future trends. Some of these technical and nontechnical subjects appeal disjoint, but they are unique and significant among the many facets, which effect the

  4. Terrestrial mobile communications

    NASA Astrophysics Data System (ADS)

    Rogard, R.; Steciw, A.

    1986-11-01

    Current and future mobile communications services in Europe are described, along with the technologies for meeting the market needs. A 450 MHz cellular system began operations in Scandinavian countries in 1981, and two 900 MHz systems entered service in the United Kingdom in 1985. Similar systems are being implemented in most European countries. Coding and access schemes are being studied for a pan-European 900 MHz system. Satellites can complement the system by providing service in coastal waters, regions of economic importance to Europe, and sparsely-populated areas. Improvements in vocodors, receiver gain, and technologies for the less-congested 14/11 or 30/20 GHz voice and data links are necessary. ESA studies with the Marecs satellite, preparatory to launch of a prototype mobile communication link, are summarized.

  5. Design considerations of 3-D single package communicator (SPC) for quad-band WCDMA\\/GSM cellular phone

    Microsoft Academic Search

    Arun Kundu; Mohamed Megahed

    2010-01-01

    A complete single package communicator (SPC) designed and implemented for 3G modem in 400 mm2 size and 1.3 mm height, for the first time is presented. With the help of 3-D technology, development of highly integrated active\\/passive components and use of latest packaging technology, the design was doable. Optimization of the RF performance of all GSM and WCDAM channels was

  6. Interworking and integration of the Inmarsat Standard-M with Pan-European GSM system

    NASA Astrophysics Data System (ADS)

    Tafazolli, R.; Evans, B. G.

    The market demand on mobile telephone communications has been increasing since the introduction of the cellular mobile telephone systems about twelve years ago. In Europe, projections indicate a demand of about 17 million subscribers for a fully deployed Pan European system. The Pan-European GSM system is to harmonize the growth of the terrestrial mobile system. Studies conducted by the European Space Agency (ESA) indicate that even with 60-70 percent of the area being covered by the GSM, a significant traffic demand (voice and data) will still exist for areas not covered by the terrestrial systems. This demand could be satisfied by a land mobile satellite system. The satellite system is therefore seen in a complementary role rather than in competition with the terrestrial system in an integrated telecommunications network. One possible scenario may be that initially the satellite system provides services to the rural areas together with areas still not covered by the GSM system. This service area is then gradually diminished as the terrestrial system expands until an optimum point is reached where the systems co-exist optimally. The objective of this paper is to investigate the possibility of integration of a space based system, in this case Inmarsat Standard-M, with the GSM (Global System for Mobile communications). One very important advantage of incorporating GSM services in Standard-M is that it will be feasible to extend the GSM services economically worldwide, not only to land mobiles but also to aeronautical and maritime mobiles.

  7. Prospects of GSM technology for academic library services

    Microsoft Academic Search

    Olayinka Catherine Fatoki

    2005-01-01

    Purpose – Poor telecommunication infrastructure has been generally identified as a hindrance to most library activities in Nigeria. However, with the emergence and spread of wireless technologies, especially the global system of mobile communications (GSM), this paper seeks to consider the implications of this event on library services, with suggestions on the possible applications to academic libraries. Design\\/methodology\\/approach – A

  8. Female Golden Eagle with GPS-GSM Transmitter

    USGS Multimedia Gallery

    From 2012-2013, telemetry data were collected from nine eagles outfitted with a backpack holding a global positioning system-global system for mobile communications, or GPS-GSM, telemetry system. The telemetry system recorded and stored a GPS location every 15-minutes and sent the locations, via the...

  9. Enhancing ecommerce security using GSM authentication

    E-print Network

    Dent, Alexander W.

    Enhancing e­commerce security using GSM authentication Vorapranee Khu­smith and Chris J. Mitchell protocol in which user authentication is provided using GSM `subscriber identity authentication'. In the protocol, a consumer is required to possess a GSM mobile station registered under a subscriber name cor

  10. GSM\\/Satellite Issues

    Microsoft Academic Search

    Heikki Einola

    In this presentation, the mobile satellite service (MSS) is regarded as complementary to the corresponding terrestrial systems.\\u000a The MSS may offer an outdoor service extension to the terrestrial mobile systems. This can be achieved with appropriate integration\\u000a of the satellites with the terrestrial system. This chapter considers the integration of mobile satellites into the GSM system.\\u000a On one hand, the

  11. UMTS-a path to 3rd generation mobile communications of the 21st century

    Microsoft Academic Search

    Juha Rapeli

    1996-01-01

    UMTS aims at advanced global mobile communication services within the WARC-92 identified frequency bands of 1885-2025 and 2110-2200 MHz. The European Telecommunications Standards Institute (ETSI) is defining UMTS as the European 3rd generation system within the global FPLMTS framework. UMTS standards and ITU recommendations for FPLMTS will be available for the introduction of systems around the year 2000. The GSM

  12. Co-Existence Study of Mobile WiMAX and GSM

    Microsoft Academic Search

    Yi Zhang; Jianyang Zhang; Tiezhu Zhao; Chengxiao Xue; SeungYong Ham

    2006-01-01

    Mobile WiMAX based on IEEE 802.16e standard has been developed for high-speed data rate applications especially in mobile environments compared with other IEEE 802 series standards. Because of scarce frequency resources, it is unavoidable to interfere the neighboring commercial mobile networks when mobile WiMAX system is deployed. Then the problem of co-existence with other mobile systems is studied. We start

  13. Modeling, Performance Analysis and Comparison of Two Level Single Chain Pointer Forwarding Strategy For Location Management in Wireless Mobile Communication

    E-print Network

    Kant, C R; Prakash, N; Kant, Chhaya Ravi; Prakash, Nupur

    2006-01-01

    Global wireless networks enable mobile users to communicate regardless of their locations. Location management is an important part of the emerging wireless and mobile technology. A Personal Communication System (PCS) network must have an efficient way to keep track of the mobile users to deliver services effectively. Global System for Mobile Communication (GSM) is a commonly accepted standard for mobility management of mobile users. Location management involves location tracking, and location information storage. Location management requires mobile users to register at various registration areas whenever they are on the move. The registration process may cause excessive signaling traffic and long service delays. To improve the efficiency of location tracking and avoid call set up delays, several strategies such as local anchor scheme, per-user caching scheme and several pointer forwarding schemes have been proposed in the past. In this paper, we propose a new "Two Level Single Chain Pointer Forwarding (TLSCP...

  14. Increased blood-brain barrier permeability in mammalian brain 7 days after exposure to the radiation from a GSM-900 mobile phone.

    PubMed

    Nittby, Henrietta; Brun, Arne; Eberhardt, Jacob; Malmgren, Lars; Persson, Bertil R R; Salford, Leif G

    2009-08-01

    Microwaves were for the first time produced by humans in 1886 when radio waves were broadcasted and received. Until then microwaves had only existed as a part of the cosmic background radiation since the birth of universe. By the following utilization of microwaves in telegraph communication, radars, television and above all, in the modern mobile phone technology, mankind is today exposed to microwaves at a level up to 10(20) times the original background radiation since the birth of universe. Our group has earlier shown that the electromagnetic radiation emitted by mobile phones alters the permeability of the blood-brain barrier (BBB), resulting in albumin extravasation immediately and 14 days after 2h of exposure. In the background section of this report, we present a thorough review of the literature on the demonstrated effects (or lack of effects) of microwave exposure upon the BBB. Furthermore, we have continued our own studies by investigating the effects of GSM mobile phone radiation upon the blood-brain barrier permeability of rats 7 days after one occasion of 2h of exposure. Forty-eight rats were exposed in TEM-cells for 2h at non-thermal specific absorption rates (SARs) of 0mW/kg, 0.12mW/kg, 1.2mW/kg, 12mW/kg and 120mW/kg. Albumin extravasation over the BBB, neuronal albumin uptake and neuronal damage were assessed. Albumin extravasation was enhanced in the mobile phone exposed rats as compared to sham controls after this 7-day recovery period (Fisher's exact probability test, p=0.04 and Kruskal-Wallis, p=0.012), at the SAR-value of 12mW/kg (Mann-Whitney, p=0.007) and with a trend of increased albumin extravasation also at the SAR-values of 0.12mW/kg and 120mW/kg. There was a low, but significant correlation between the exposure level (SAR-value) and occurrence of focal albumin extravasation (r(s)=0.33; p=0.04). The present findings are in agreement with our earlier studies where we have seen increased BBB permeability immediately and 14 days after exposure. We here discuss the present findings as well as the previous results of altered BBB permeability from our and other laboratories. PMID:19345073

  15. GSM Cell Site Porensics

    NASA Astrophysics Data System (ADS)

    Swenson, Christopher; Moore, Tyler; Shenoi, Sujeet

    Cell site forensics is a new and growing area of digital forensics, enabling investigators to verify a mobile phone subscriber's location at specific times. This paper focuses on cell site forensics in GSM networks. In particular, it discusses current methods utilizing call detail records generated from telephone switches that provide information about cellular calls and text messages, and the cellular towers on which calls/messages were placed and received.

  16. Smart Cards for Mobile Communications

    Microsoft Academic Search

    Keith Mayes; Tim Evans

    There are well over 2 billion smart cards in use today within mobile communications devices. The cards known as Subscriber\\u000a Identity Modules ((U)SIMs) represent some of the most technically advanced smart cards that have ever been deployed. Their\\u000a original role was to safeguard the system security by providing authentication and confidentiality, but they have evolved\\u000a to support additional security and

  17. Personal mobile communications in microwave band

    Microsoft Academic Search

    Yuji Kitahara

    1993-01-01

    The mobile communications technologies have been extremely-evolved during the past few years. The various types of mobile communications services such as mobile telephone, paging, teleterminal and so-on are in operation in many countries. The analogue cellular system is migrating to the digital cellular system and the high speed data services in the paging system will be launched in the near

  18. Les interfaces intelligentes et les communications mobiles

    E-print Network

    Paris-Sud XI, Université de

    Chapitre 7 Les interfaces intelligentes et les communications mobiles Badr Benmammar Laboratoire #12;Les interfaces intelligentes et les communications mobiles 3 Le reste de ce chapitre est organisé communicants : mobilité, sécurité, autonomie (Traité IC2, série réseaux et télécoms) Lavoisier librairie (Ed

  19. Can active tracking of inroamer location optimise a live GSM network?

    Microsoft Academic Search

    Katerina Dufková; Jirí Danihelka; Michal Ficek; Ivan Gregor; Jan Kouba

    2007-01-01

    The mobile communication industry has experienced huge growth in recent years, which amplified the competition am- ong telecommunication companies. This inspired the search for new means of GSM network optimization that would bring better signal coverage and thus competitive advantage. One of the possibilities is active tracking of inroamer loca- tion in order to find where they disappear to a

  20. Design and Implementation of Vehicle Monitoring System Based on GPS\\/GSM\\/GIS

    Microsoft Academic Search

    Hui Hu; Lian Fang

    2009-01-01

    Based on the background that vehicle monitoring system had urgent necessity recently, the paper put forward a overall scheme of vehicle monitoring system combining with global positioning system (GPS), global system for mobile communication (GSM) and geographical information system (GIS), introduced the key technologies of this monitoring center software, designed the function software of monitoring center based on VC++ software

  1. A review of mobile satellite communication systems

    NASA Astrophysics Data System (ADS)

    Kondo, Kimio

    1990-03-01

    This article describes mobile satellite systems in the planning or development stage such as MSAT, AMSC and Geostar and mobile satellite communication experiments such as PRODAT. Studies on the system such as T-SAT are also reviewed. In addition, Japanese ETS-V and ETS-VI are described. The development of mobile-satellite communication systems is promoted along with those of communication and satellite technologies.

  2. Optimizing frequency planning in the GSM system

    Microsoft Academic Search

    Andrea De Pasquale; N. P. Magnani; Paolo Zanini

    1998-01-01

    Frequency planning is an important process in planning and optimising second generation TDMA mobile networks. For the GSM system, frequency planning is usually performed by controlling only the downlink estimated quality in the territory. In this paper, by means of simulation results, field measurements and theoretical analysis, we verify that the uplink and downlink in the GSM system experience a

  3. Enhancing e-commerce security using GSM authentication

    E-print Network

    Mitchell, Chris

    Enhancing e-commerce security using GSM authentication Vorapranee Khu-smith and Chris J. Mitchell authentication is provided using GSM `subscriber identity authentication'. In the pro- tocol, a consumer is required to possess a GSM mobile station registered under a subscriber name corresponding to that on his

  4. Subjective symptoms related to GSM radiation from mobile phone base stations: a cross-sectional study

    PubMed Central

    Gómez-Perretta, Claudio; Navarro, Enrique A; Segura, Jaume; Portolés, Manuel

    2013-01-01

    Objectives We performed a re-analysis of the data from Navarro et al (2003) in which health symptoms related to microwave exposure from mobile phone base stations (BSs) were explored, including data obtained in a retrospective inquiry about fear of exposure from BSs. Design Cross-sectional study. Setting La Ńora (Murcia), Spain. Participants Participants with known illness in 2003 were subsequently disregarded: 88 participants instead of 101 (in 2003) were analysed. Since weather circumstances can influence exposure, we restricted data to measurements made under similar weather conditions. Outcomes and methods A statistical method indifferent to the assumption of normality was employed: namely, binary logistic regression for modelling a binary response (eg, suffering fatigue (1) or not (0)), and so exposure was introduced as a predictor variable. This analysis was carried out on a regular basis and bootstrapping (95% percentile method) was used to provide more accurate CIs. Results The symptoms most related to exposure were lack of appetite (OR=1.58, 95% CI 1.23 to 2.03); lack of concentration (OR=1.54, 95% CI 1.25 to 1.89); irritability (OR=1.51, 95% CI 1.23 to 1.85); and trouble sleeping (OR=1.49, 95% CI 1.20 to 1.84). Changes in –2 log likelihood showed similar results. Concerns about the BSs were strongly related with trouble sleeping (OR?=3.12, 95% CI 1.10 to 8.86). The exposure variable remained statistically significant in the multivariate analysis. The bootstrapped values were similar to asymptotic CIs. Conclusions This study confirms our preliminary results. We observed that the incidence of most of the symptoms was related to exposure levels—independently of the demographic variables and some possible risk factors. Concerns about adverse effects from exposure, despite being strongly related with sleep disturbances, do not influence the direct association between exposure and sleep. PMID:24381254

  5. Satellite communication and navigation for mobile users

    NASA Technical Reports Server (NTRS)

    Bernstein, S. L.

    1972-01-01

    Efforts made to utilize space technology for solving communication and navigation problems faced by mobile users in earth orientated situations are outlined. Applications include transoceanic airline communications, reliable long range ship-shore communications, emergency communications in regions with rough terrain, and military operations.

  6. Antennas for mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Huang, John

    1991-01-01

    A NASA sponsored program, called the Mobile Satellite (MSAT) system, has prompted the development of several innovative antennas at L-band frequencies. In the space segment of the MSAT system, an efficient, light weight, circularly polarized microstrip array that uses linearly polarized elements was developed as a multiple beam reflector feed system. In the ground segment, a low-cost, low-profile, and very efficient microstrip Yagi array was developed as a medium-gain mechanically steered vehicle antenna. Circularly shaped microstrip patches excited at higher-order modes were also developed as low-gain vehicle antennas. A more recent effort called for the development of a 20/30 GHz mobile terminal antenna for future-generation mobile satellite communications. To combat the high insertion loss encountered at 20/30 GHz, series-fed Monolithic Microwave Integrated Circuit (MMIC) microstrip array antennas are currently being developed. These MMIC arrays may lead to the development of several small but high-gain Ka-band antennas for the Personal Access Satellite Service planned for the 2000s.

  7. Experiment In Aeronautical-Mobile/Satellite Communication

    NASA Technical Reports Server (NTRS)

    Jedrey, Thomas C.; Lay, Norman E.; Dessouky, Khaled

    1992-01-01

    Report describes study of performance of digital mobile/satellite communication terminals of advanced design intended for use in ground stations and airplanes in aeronautical-mobile service. Study was collaboration of NASA, Federal Aviation Administration (FAA), Communications Satellite Corp. (COMSAT), and International Maritime Satellite System (INMARSAT).

  8. Department of Mobile Communications Campus Sophia Tech

    E-print Network

    Gesbert, David

    interest or providing access to resources or services between peers can enhance a mobile node . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4 Case Study: Mobile Data Offloading 15 4.1 Case 1: no QoS constraintsEURECOM Department of Mobile Communications Campus Sophia Tech Les Templiers 450 route des Chappes

  9. Effective Protocols for Mobile Communications and Networking

    SciTech Connect

    Espinoza, J.; Sholander, P.; Van Leeuwen, B,

    1998-12-01

    This report examines methods of mobile communications with an emphasis on mobile computing and wireless communications. Many of the advances in communications involve the use of Internet Protocol (IP), Asynchronous Transfer Mode (ATM), and ad hoc network protocols. However, many of the advances in these protocols have been focused on wired communications. Recently much focus has been directed at advancing communication technology in the area of mobile wireless networks. This report discusses various protocols used in mobile communications and proposes a number of extensions to existing protocols. A detailed discussion is also included on desirable protocol characteristics and evaluation criteria. In addition, the report includes a discussion on several network simulation tools that maybe used to evaluate network protocols.

  10. Authentication and Encryption in GSM and 3GUMTS: An Emphasis on Protocols and Algorithms

    E-print Network

    Elouafiq, Ali

    2012-01-01

    Mobile communication touches every aspect of our life, it become one of the major dependencies that the 21st Century civilizations rely on. Thereby, security is a major issue that should be targeted by communication technologies. In this paper we will target authentication and encryption in GSM and 3G/UMTS. In order to understand clearly how things work, we will start by presenting the architecture of each network, its major components, its authentication algorithms, protocols used, and KASUMI Block Cipher.

  11. Pharos: coupling GSM and GPS-TALK technologies to provide orientation, navigation and location-based services for the blind

    Microsoft Academic Search

    A. Marsh; M. May; M. Saarelainen

    2000-01-01

    Millions of people are already experiencing with GSM the freedom of going mobile for voice and Internet access. This freedom is reshaping every aspect of our lives; the way we do business, the way we buy things and the way we communicate. For the blind, when combined with GPS, it could also add the freedom of movement. The paper considers

  12. Mobile Phones as Fashion Statements: The Co-creation of Mobile Communication’s Public Meaning

    Microsoft Academic Search

    James E. Katz; Satomi Sugiyama

    This chapter explores public mobile communication technology as frontstage and back-stage phenomena. We explore the design aesthetics of the mobile phone from the standpoint of its commercial origins and public re-interpretation, emphasizing fashion and identity in the co-creation and consumption of mobile communication technology. The mobile phone in this context is analyzed as both a physical icon and an item

  13. Context-Aware Dynamic Security Configuration for Mobile Communication Device

    Microsoft Academic Search

    Gaeil An; Guntae Bae; Kiyoung Kim; Dongil Seo

    2009-01-01

    A mobile communication device is a small size of portable computer which provides communication service. One of the biggest barriers in developing the mobile communication device is security. To protect itself against security threats, the mobile communication device need to be loaded with various kinds of security functions such as firewall, access control, and so on. However because the mobile

  14. Spread spectrum mobile radio communications

    NASA Astrophysics Data System (ADS)

    Gupta, S. C.; Sandeep, C.; Refai, W.

    1989-09-01

    Two problems are studied. The first is concerned with evaluating the performance of a class of bandwidth efficient modulation schemes in a frequency reuse mobile radio channel. The second problem is concerned with formulating and evaluating the performance of a class of known delay multipath diversity receivers for indoor wireless communication. Several partial response (PRCPM) schemes such as TFM, GMSK and 3RC are compared with regard to their performance in the presence of Adjacent Channel Interference (ACI) and CoChannel Interference (CCI). The performance criteria chosen were average probability of bit error and mean-square cross talk ratio. A comparison of three receiver filters with regard to their ability to reject ACI is also provided. Results indicate that receiver filter length is very important parameter for good performance. The performance of PRCPM schemes is analyzed by considering the combined effects of ACI, CCI and Rayleigh fading. The analysis is extended to the case when space diversity is employed. Results indicate that by using space diversity and maximal Ration Combining significant performance gains can be achieved.

  15. EECE 569 -UBC ECE -Outline Outline-1 Mobile Communications Networks

    E-print Network

    Pulfrey, David L.

    Wireless wireline interworking Mobile IP Simulations of wireless networks Security in wireless networksEECE 569 - UBC ECE - Outline Outline-1 EECE 569 Mobile Communications Networks http Objectives Aspects of mobile communications networks Architectures, protocols and management techniques

  16. Multihop communications in future mobile radio networks

    Microsoft Academic Search

    H. Li; M. Lott; M. Weckerle; W. Zirwas; E. Schulz

    2002-01-01

    Cellular networks and wireless local area networks (WLAN) are being widely deployed for mobile radio communications. Taking into account the advantageous and drawbacks of both network architectures, it becomes obvious that a combination of them is the logical consequence for future mobile radio networks. The scope of this paper is to introduce a future radio network architecture called hierarchical multihop

  17. Application of mobile router to military communications

    Microsoft Academic Search

    David H. Stewart; William D. Ivancic; Terry L. Bell; Brian A. Kachmar; D. Shell; K. Leung

    2001-01-01

    Cisco Systems and NASA Glenn Research Center under a NASA Space Act Agreement have been performing joint networking research to apply Internet technologies and protocols to space-based communications. During this time, Cisco Systems developed the mobile router which NASA and Cisco jointly tested. The early field trials of this technology have been successfully completed. The mobile router is software code

  18. Repeated Transmissions In Mobile/Satellite Communications

    NASA Technical Reports Server (NTRS)

    Yan, Tsun-Yee; Clare, Loren P.

    1988-01-01

    Repetition increases throughput and decreases delay. Paper discusses theoretical performance of communication system for land-mobile stations with satellite relay using ALOHA random-access protocol modified for repeated transimssions. Methods and conclusions contribute to general understanding of packet communications in fading channels.

  19. Solutions to the GSM Security Weaknesses

    E-print Network

    Toorani, Mohsen; 10.1109/NGMAST.2008.88

    2010-01-01

    Recently, the mobile industry has experienced an extreme increment in number of its users. The GSM network with the greatest worldwide number of users succumbs to several security vulnerabilities. Although some of its security problems are addressed in its upper generations, there are still many operators using 2G systems. This paper briefly presents the most important security flaws of the GSM network and its transport channels. It also provides some practical solutions to improve the security of currently available 2G systems.

  20. Radio Frequency Electromagnetic Radiation (RF-EMR) from GSM (0.9/1.8GHZ) Mobile Phones Induces Oxidative Stress and Reduces Sperm Motility in Rats

    PubMed Central

    Mailankot, Maneesh; Kunnath, Anil P; Jayalekshmi, H; Koduru, Bhargav; Valsalan, Rohith

    2009-01-01

    INTRODUCTION: Mobile phones have become indispensable in the daily lives of men and women around the globe. As cell phone use has become more widespread, concerns have mounted regarding the potentially harmful effects of RF-EMR from these devices. OBJECTIVE: The present study was designed to evaluate the effects of RF-EMR from mobile phones on free radical metabolism and sperm quality. MATERIALS AND METHODS: Male albino Wistar rats (10–12 weeks old) were exposed to RF-EMR from an active GSM (0.9/1.8 GHz) mobile phone for 1 hour continuously per day for 28 days. Controls were exposed to a mobile phone without a battery for the same period. The phone was kept in a cage with a wooden bottom in order to address concerns that the effects of exposure to the phone could be due to heat emitted by the phone rather than to RF-EMR alone. Animals were sacrificed 24 hours after the last exposure and tissues of interest were harvested. RESULTS: One hour of exposure to the phone did not significantly change facial temperature in either group of rats. No significant difference was observed in total sperm count between controls and RF-EMR exposed groups. However, rats exposed to RF-EMR exhibited a significantly reduced percentage of motile sperm. Moreover, RF-EMR exposure resulted in a significant increase in lipid peroxidation and low GSH content in the testis and epididymis. CONCLUSION: Given the results of the present study, we speculate that RF-EMR from mobile phones negatively affects semen quality and may impair male fertility. PMID:19578660

  1. Communication Systems Chair of Communication Systems

    E-print Network

    Schindelhauer, Christian

    ;3 | 36 Communication Systems GSM interfaces and components #12;4 | 36 Communication Systems GSM (HLR) #12;5 | 36 Communication Systems GSM interfaces and components The several MSC (Operation and Maintenance Center) ­ Network Administration #12;6 | 36 Communication Systems GSM interfaces

  2. Satellite multiple access systems for mobile communication

    NASA Technical Reports Server (NTRS)

    Lewis, J. L.

    1979-01-01

    This paper considers multiple access techniques for a mobile radio system which incorporates a geosynchronous orbiting satellite repeater through which mobile terminals communicate. The communication capacities of FDMA, TDMA and CDMA systems are examined for a 4 MHz bandwidth system to serve up to 10,000 users. An FDMA system with multibeam coverage is analyzed in detail. The system includes an order-wire network for demand-access control and reassignment of satellite channels. Satellite and terminal configurations are developed to a block diagram level and system costs and implementation requirements are discussed.

  3. Anonymous communications in mobile ad hoc networks

    Microsoft Academic Search

    Yanchao Zhang; Wei Liu; Wenjing Lout

    2005-01-01

    Abstract—Due to the broadcast nature of radio transmissions, communications in mobile ad hoc networks (MANETs) are more susceptible to malicious traffi ca nalysis. In this paper we propose a novel anonymous on-demand routing protocol, termed MASK, to enable anonymous,communications thereby thwarting possible traffic analysis attacks. Based on a new cryptographic concept called pairing, we first propose an anonymous neighborhood authentication

  4. Integration between terrestrial-based and satellite-based land mobile communications systems

    NASA Technical Reports Server (NTRS)

    Arcidiancono, Antonio

    1990-01-01

    A survey is given of several approaches to improving the performance and marketability of mobile satellite systems (MSS). The provision of voice/data services in the future regional European Land Mobile Satellite System (LMSS), network integration between the Digital Cellular Mobile System (GSM) and LMSS, the identification of critical areas for the implementation of integrated GSM/LMSS areas, space segment scenarios, LMSS for digital trunked private mobile radio (PMR) services, and code division multiple access (CDMA) techniques for a terrestrial/satellite system are covered.

  5. Time reversal communication with a mobile source.

    PubMed

    Song, H C

    2013-10-01

    Broadband underwater acoustic communication signals undergo either a compression or dilation in the presence of relative motion between a source and a receiver. Consequently, underwater acoustic communications with a mobile source/receiver require Doppler compensation through resampling. However, resampling may not be necessary when a channel-estimate-based time reversal approach is applied with frequent channel updates. Using experimental data (20-30 kHz), it is demonstrated that the performance of time reversal communication without resampling is similar to the case with resampling, along with the benefit of a modest computational saving. PMID:24116398

  6. Communicating and Mobile Systems: The ?-calculus

    Microsoft Academic Search

    Robin Milner

    1999-01-01

    The pi-calculus differs from other models of communicating behaviour mainly in its treatment of mobility. The movement of a piece of data inside a computer program is treated exactly the same as the transfer of a message - or indeed an entire computer program - across the internet. One can also describe networks which reconfigure themselves. The calculus is very

  7. WIRELESS COMMUNICATIONS MOBILE COMPUTING Wirel. Commun. Comput.

    E-print Network

    Giannakis, Georgios

    broadband wireless communications. survey space -- time coding schemes is provided this paper. Targeting references therein). these systems, exceed Mbps while mobile units may move as a high­speed train with user combat fading exploitation diversity. Accord­ domain where diversity is created, diversity techniques may

  8. Mobile Communication Security Controllers An Evaluation Paper

    E-print Network

    Mayes, Keith

    Mobile Communication Security Controllers An Evaluation Paper Keith E. Mayes, Konstantinos that types of "Software SIM" should be used as an alternative to the smart card based solution. This paper and services against criminal mis-use remains and indeed has become more acute as electronic applications

  9. Secure asynchronous communication for mobile devices

    Microsoft Academic Search

    Pierre Henri Kuaté; Johnny Li-Chang Lo; Judith Bishop

    2009-01-01

    Mobile devices are now used not only for communication but also as working units. As more sensitive information is stored on and transmitted through these devices, security is becoming a growing concern. This is especially true for SMS messages which do not integrate any security mechanism. This is why we propose a simple-to-use but cryptographically strong API for message encryption

  10. Smart Card based Solution for Non-Repudiation in GSM WAP Applications

    Microsoft Academic Search

    C RISTIAN TOMA; MARIUS POPA; CATALIN BOJA; Cristian Toma

    http:\\/\\/www.ase.ro A bstract: The paper presents security issues and architectures for mobile applications and GSM infrastructure. The article also introduces the solution for avoiding denial of service from WAP applications using WIM features. The first section contains the structure of GSM network from voice and data point of view. The security in GSM network is presented in second section. The

  11. Comparison of Exact and Approximate Multi-User Detection for GSM

    E-print Network

    Comparison of Exact and Approximate Multi-User Detection for GSM Lili Nie Informatics and Mathematical Modelling Technical University of Denmark #12;#12;Abstract In today's Group Spécial Mobile (GSM GSM receivers. It is shown that exact MUD solution provides a big Bit Error Rate (BER) gain compared

  12. Modelling of handover of multimedia traffic in mobile satellite communication

    Microsoft Academic Search

    A. Sali; N. K. Noordin; B. M. Ali; R. K. Z. Sahbudin; A. Anthony; Ng Chee Kyun

    2002-01-01

    This paper presents the handover management in mobile satellite communications with multimedia traffic. Multimedia traffic is becoming the next hop in mobile satellite communication, due to its demand. The coverage of the satellite network knows no boundary and with the concept of the broadband satellite network, communication for multimedia and high-data rate multimedia communications can be provided. The handover initiation

  13. Spread spectrum mobile radio communications

    NASA Astrophysics Data System (ADS)

    Gupta, S. C.

    1982-12-01

    In this report, we analyze the performance of frequency-hopped spread-spectrum systems under mobile radio channel conditions. Because of its good spectrum-efficiency, frequency-hopped systems seen to be natural candidates for mobile telephony in the near future. We analyze mainly the Frequency-Hopped-Multilevel Frequency Shift-Keyed (FH-MFSK) System, the reason being the established superiority of FH-MFSK over the other modulation, namely the Frequency-Hopped Differential Phase Shift Keyed system (FH-DPSK), under identical conditions. Our new results include the spectrum efficiency analysis of FH-MFSK for various bandwidths of interest, the performance analysis of FH-MFSK under the influence of log-normal shadowing and Rayleigh fading, the possible performance improvement with the inclusion of a small number of space-diversity branches to combat the losses due to fading, a preliminary analysis of the occurrence of burst errors in FH systems, the amount of degradation due to the users operating in the adjacent cells and a possible power control scheme to mitigate these effects and finally a result which establishes the near-equivalent performance of the hard-limited and the likelihood receivers under Rayleigh fading and multi-user interference conditions.

  14. Near Field Communication im Mobile Marketing

    Microsoft Academic Search

    K.-P. Wiedmann; M.-O. Reeh; H Schumacher

    Near Field Communication (NFC) ist eine Kurzstrecken-Funktechnologie für die anwenderfreundliche Vernetzung mobiler Endgeräte\\u000a wie Handys, PDAs und Smartphones untereinander sowie mit feststehenden Einheiten wie Kunden- oder EC-Terminals. Technisch\\u000a eng verwandt mit kontaktlosen Chipkarten und den jüngst vieldiskutierten Radio Frequency Identification-Systemen (RFID) wollen\\u000a Gerätehersteller, Netzbetreiber und Serviceprovider NFC in Zukunft verstärkt dazu nutzen, interessierten Mobilfunkkunden neue\\u000a Dienste zu offerieren, die dem

  15. National Security, Forensics and Mobile Communications

    Microsoft Academic Search

    David Naccache

    2005-01-01

    \\u000a There are nearly 1.5 billion handset users in the world. As the recent attacks in London illustrate, this proliferation of\\u000a inexpensive mobile phones provides criminals and terrorists with flexible communication means. In this talk we will describe\\u000a the forensic methodology used for analysing SIM cards and handsets within the French legal context. We will describe specific\\u000a technical problems applicable to

  16. Exploiting Doppler Diversity In Mobile Wireless Communications

    Microsoft Academic Search

    Akbar M. Sayeed; Behnaam Aazhang

    1997-01-01

    Signal fading due to variations in channel characteristicsis one of the major factors limiting the performance ofmodern mobile wireless communication systems. To overcomefading, various diversity techniques have been developedthat effectively transmit multiple copies of the signalover the channel. The state-of-the-art receiver used incode-division multiple access systems is the RAKE receiverthat exploits multipath diversity. However, the RAKE receiverassumes slow channel variations

  17. Ray-Tracing for Mobile Communications

    Microsoft Academic Search

    Sandra Knorzer; Thomas Fugen; Werner Wiesbeck

    For the parametrization and standardization of future mobile communications systems realistic values of the characteristic channel parameters are needed. Due to its ability to analyze the frequency-selective, time-variant as well as spa- tial behavior of the channel, ray-tracing is a popular channel characterization method. Moreover, it is capable to calculate very large structures (i.e. site-specific scenarios) with reasonable computation resources.

  18. Learning significant user locations with GPS and GSM

    E-print Network

    Yu, Xiao, M. Eng. Massachusetts Institute of Technology

    2006-01-01

    This thesis addresses the tasks of place discovery and place recognition - learning and recognizing places significant to a user - by analyzing GPS location and GSM cell tower data collected from the user's mobile phone. ...

  19. Adaptive Beamforming in Mobile, Massively Multiuser Satellite Communications: A System

    E-print Network

    Gesbert, David

    Adaptive Beamforming in Mobile, Massively Multiuser Satellite Communications: A System Perspective Xiao Lei, Laura Cottatellucci, Samah A. M. Ghanem Mobile Communications Department, Eurecom, France Email: {xiao.lei; laura.cottatellucci; samah.ghanem}@eurecom.fr Abstract--We consider a Mobile Satellite

  20. Does exposure to GSM 900 MHz mobile phone radiation affect short-term memory of elementary school students?

    PubMed Central

    Movvahedi, M. M.; Tavakkoli-Golpayegani, A.; Mortazavi, S. A. R.; Haghani, M.; Razi, Z.; Shojaie-fard, M. B.; Zare, M.; Mina, E.; Mansourabadi, L.; Nazari-Jahromi; Safari, A.; Shokrpour, N.; Mortazavi, S. M. J.

    2014-01-01

    Background: Now-a-days, children are exposed to mobile phone radiation at a very early age. We have previously shown that a large proportion of children in the city of Shiraz, Iran use mobile phones. Furthermore, we have indicated that the visual reaction time (VRT) of university students was significantly affected by a 10 min real/sham exposure to electromagnetic fields emitted by mobile phone. We found that these exposures decreased the reaction time which might lead to a better response to different hazards. We have also revealed that occupational exposures to radar radiations decreased the reaction time in radar workers. The purpose of this study was to investigate whether short-term exposure of elementary school students to radiofrequency (RF) radiation leads to changes in their reaction time and short-term memory. Materials and Methods: A total of 60 elementary school children ages ranging from 8 to 10 years studying at a public elementary school in Shiraz, Iran were enrolled in this study. Standardized computer-based tests of VRT and short-term memory (modified for children) were administered. The students were asked to perform some preliminary tests for orientation with the VRT test. After orientation, to reduce the random variation of measurements, each test was repeated ten times in both real and sham exposure phases. The time interval between the two subsequent sham and real exposure phases was 30 min. Results: The mean ± standard deviation reaction times after a 10 min talk period and after a 10 min sham exposure (switched off mobile) period were 249.0 ± 82.3 ms and 252.9 ± 68.2 ms (P = 0.629), respectively. On the other hand, the mean short-term memory scores after the talk and sham exposure periods were 1062.60 ± 305.39, and 1003.84 ± 339.68 (P = 0.030), respectively. Conclusion: To the best of our knowledge, this is the first study to show that short-term exposure of elementary school students to RF radiation leads to the better performance of their short-term memory. PMID:25250064

  1. FH-GSM frequency hopping GSM

    Microsoft Academic Search

    C. Carneheim; Sven-Olof Jonsson; Malin Ljungberg; Magnus Madfors; Jonas Naslund

    1994-01-01

    The GSM system of today is evolving towards smaller cells and higher traffic capacity. The need for microcell and even picocell systems will be greatly increased in the near future. One of the most important factors will then be to provide high traffic capacity and to provide an easy way of performing frequency planning for the system operator. In this

  2. Performance Analysis of GSM Networks with Intelligent UnderlayOverlay Khalid Begain 1 , Gergo Istvan Rozsa 2 , Andras Pfening 3 , Miklos Telek 4y

    E-print Network

    Telek, Miklós

    Performance Analysis of GSM Networks with Intelligent Underlay­Overlay #3; Khalid Begain 1 , Gerg an analytical model for a GSM­based cellular mobile network that applies the Intelligent Under­ Overlay (IUO and average mobile speed. Keywords: Cellular mobile networks, GSM, IUO, Per­ formance analysis. 1 Introduction

  3. Precise design technique for a SAW-resonator-coupled filter on 36° YX-LiTaO3 for use in a GSM SAW duplexer module for satisfying all GSM system specifications

    Microsoft Academic Search

    N. Shibagaki; K. Sakiyama; M. Hikita

    1996-01-01

    A miniature low-loss high-performance surface acoustic wave (SAW) duplexer module consisting of a receiver top filter (R1), transmitter final stage filter (T1), lumped matching-circuit elements and lumped phase-shift circuits has been developed, and its use in the Global System for Mobile Communication (GSM) is described as a design example. The complete duplexer module has an insertion loss of less than

  4. MACCS: enabling communications for mobile workers within healthcare environments

    Microsoft Academic Search

    Michael J. Sammon; Lynne Shapiro Brotman; Ed Peebles; Dorée Duncan Seligmann

    2006-01-01

    As wireless communications systems become more ubiquitous, enterprise workers are becoming more and more mobile. Addressing mobility in the enterprise has recently become a pressing concern for many corporations. In particular, there is a growing component of mobile workers whose job tasks require them to be mobile within their local workspace. These workers sometimes do not have a desk or

  5. Cluestr: mobile social networking for enhanced group communication

    Microsoft Academic Search

    Reto Grob; Michael Kuhn; Roger Wattenhofer; Martin Wirz

    2009-01-01

    Recent technological advances foster the spreading of social software in the mobile domain. Hence, future usage patterns of mobile devices will involve more group interaction. While collaboration using mobile devices is an active area of re- search, only limited attention has been paid to the efficient initiation of group communication from mobile terminals. In this paper we present a community-aware

  6. Route Optimization for Intra Communication of a Nested Mobile Network

    E-print Network

    National University hscho@mmlab.snu.ac.kr ABSTRACT Network mobility, i.e. Internet access services.11/16) and mobile communication services, the demand for Internet access in mobile vehicles such as trains, buses is referred to as network mobility (NEMO) support. To address the NEMO support problem, Internet Engineering

  7. Hybrid Mobile Communication Networks for Planetary Exploration

    NASA Technical Reports Server (NTRS)

    Alena, Richard; Lee, Charles; Walker, Edward; Osenfort, John; Stone, Thom

    2007-01-01

    A paper discusses the continuing work of the Mobile Exploration System Project, which has been performing studies toward the design of hybrid communication networks for future exploratory missions to remote planets. A typical network could include stationary radio transceivers on a remote planet, mobile radio transceivers carried by humans and robots on the planet, terrestrial units connected via the Internet to an interplanetary communication system, and radio relay transceivers aboard spacecraft in orbit about the planet. Prior studies have included tests on prototypes of these networks deployed in Arctic and desert regions chosen to approximate environmental conditions on Mars. Starting from the findings of the prior studies, the paper discusses methods of analysis, design, and testing of the hybrid communication networks. It identifies key radio-frequency (RF) and network engineering issues. Notable among these issues is the study of wireless LAN throughput loss due to repeater use, RF signal strength, and network latency variations. Another major issue is that of using RF-link analysis to ensure adequate link margin in the face of statistical variations in signal strengths.

  8. Advanced communications payload for mobile applications

    NASA Technical Reports Server (NTRS)

    Ames, S. A.; Kwan, R. K.

    1990-01-01

    An advanced satellite payload is proposed for single hop linking of mobile terminals of all classes as well as Very Small Aperture Terminal's (VSAT's). It relies on an intensive use of communications on-board processing and beam hopping for efficient link design to maximize capacity and a large satellite antenna aperture and high satellite transmitter power to minimize the cost of the ground terminals. Intersatellite links are used to improve the link quality and for high capacity relay. Power budgets are presented for links between the satellite and mobile, VSAT, and hub terminals. Defeating the effects of shadowing and fading requires the use of differentially coherent demodulation, concatenated forward error correction coding, and interleaving, all on a single link basis.

  9. Frequency addressable beams for land mobile communications

    NASA Technical Reports Server (NTRS)

    Thompson, J. D.; Dubellay, G. G.

    1988-01-01

    Satellites used for mobile communications need to serve large numbers of small, low cost terminals. The most important parameters affecting the capacity of such systems are the satellite equivalent isotropically radiated power (EIRP) and gain to noise temperature ratio (G/T) and available bandwidth. Satellites using frequency addressed beams provide high EIRP and G/T with high-gain antenna beams that also permit frequency reuse over the composite coverage area. Frequency addressing is easy to implement and compatible with low-cost terminals and offers higher capacity than alternative approaches.

  10. IEEE Communications Magazine July 199790 Rayleigh Fading Channels in Mobile

    E-print Network

    Howard, Sheryl

    IEEE Communications Magazine · July 199790 Rayleigh Fading Channels in Mobile Digital Communication of transmitted power is attenuated by a factor, Ls(d), where this factor is called path loss or free space loss

  11. Development of an ANFIS-based QoS model for a GSM service provider (MTN Nigeria Kano region network)

    Microsoft Academic Search

    S. Garba; B. G. Bajoga; M. B. Mu'azu; D. D. Dajab; U.-F. Abdu-Aguye

    2011-01-01

    MTN Nigeria is one of the leading GSM service providers in Nigeria with 40 million subscribers and as such Quality of Service (QoS) is of vital importance. Due to the mobility of subscribers and the complexity of radio waves in propagation, the radio part (GSM Capacity) is mostly the decisive factor affecting the Quality of Service of the GSM network.

  12. 75 FR 3914 - Recordation of Trade Name “Sony Ericsson Mobile Communications AB”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ...by Sony Ericsson Mobile Communications AB. The application for trade name recordation...name, Sony Ericsson Mobile Communications AB...published a notice of application for the recordation...Sony Ericsson Mobile Communications...

  13. Key Issues in Expansion of Mobile Data Communications in China

    Microsoft Academic Search

    Sunanda Sangwan; Chong Guan; Louis-Francois Pau

    2008-01-01

    China's mobile communications market presents unique market challenges. Market is experiencing a high subscriber growth rate and its implications for business and end-users and investigation into the current status of this market will improve our understanding on how adoption of mobile communications is evolving at the end-user level. In this paper we use a descriptive method to analyze key issues

  14. Family guard against theft and alarm system based on GSM Modem

    Microsoft Academic Search

    Zhou Yu; Zhisong Hou; Gaoli Zhao; Xiangang Zuo

    2011-01-01

    The System is made up of MCU and GSM Modem. It will display the alarm content in Chinese directly at your mobile screen, and it recurs to the most reliable GSM mobile network. The system adopted initiative infrared sensor to detect, and it turned the traditional alarm net and alarm windows to immateriality. Besides, the system equipped the smog sensor

  15. Land vehicle antennas for satellite mobile communications

    NASA Technical Reports Server (NTRS)

    Haddad, H. A.; Paschen, D.; Pieper, B. V.

    1985-01-01

    Antenna designs applicable to future satellite mobile vehicle communications are examined. Microstrip disk, quadrifilar helix, cylindrical microstrip, and inverted V and U crossed-dipole low gain antennas (3-5 dBic) that provide omnidirectional coverage are described. Diagrams of medium gain antenna (9-12 dBic) concepts are presented; the antennas are classified into three types: (1) electronically steered with digital phase shifters; (2) electronically switched with switchable power divider/combiner; and (3) mechanically steered with motor. The operating characteristics of a conformal antenna with electronic beam steering and a nonconformal design with mechanical steering are evaluated with respect to isolation levels in a multiple satellite system. Vehicle antenna pointing systems and antenna system costs are investigated.

  16. SAW based systems for mobile communications satellites

    NASA Technical Reports Server (NTRS)

    Peach, R. C.; Miller, N.; Lee, M.

    1993-01-01

    Modern mobile communications satellites, such as INMARSAT 3, EMS, and ARTEMIS, use advanced onboard processing to make efficient use of the available L-band spectrum. In all of these cases, high performance surface acoustic wave (SAW) devices are used. SAW filters can provide high selectivity (100-200 kHz transition widths), combined with flat amplitude and linear phase characteristics; their simple construction and radiation hardness also makes them especially suitable for space applications. An overview of the architectures used in the above systems, describing the technologies employed, and the use of bandwidth switchable SAW filtering (BSSF) is given. The tradeoffs to be considered when specifying a SAW based system are analyzed, using both theoretical and experimental data. Empirical rules for estimating SAW filter performance are given. Achievable performance is illustrated using data from the INMARSAT 3 engineering model (EM) processors.

  17. Interference analysis for an Aeronautical Mobile Airport Communications System

    Microsoft Academic Search

    Jeffrey D. Wilson; Robert J. Kerczewski

    2011-01-01

    The next generation of aeronautical communications for airport surface applications has been identified through a NASA research program and an international collaborative future communications study. The result, endorsed by both the United States and European regulatory agencies is called AeroMACS (Aeronautical Mobile Airport Communications System) and is based upon the IEEE 802.16e mobile wireless standard. Coordinated efforts to develop appropriate

  18. A Novel Model for Optimized GSM Network Design

    E-print Network

    de Aguiar, Alexei Barbosa; Neto, Alvaro de Menezes S; Cunha, Ruddy P P; Pinheiro, Rebecca F

    2009-01-01

    GSM networks are very expensive. The network design process requires too many decisions in a combinatorial explosion. For this reason, the larger is the network, the harder is to achieve a totally human based optimized solution. The BSC (Base Station Control) nodes have to be geographically well allocated to reduce the transmission costs. There are decisions of association between BTS and BSC those impacts in the correct dimensioning of these BSC. The choice of BSC quantity and model capable of carrying the cumulated traffic of its affiliated BTS nodes in turn reflects on the total cost. In addition, the last component of the total cost is due to transmission for linking BSC nodes to MSC. These trunks have a major significance since the number of required E1 lines is larger than BTS to BSC link. This work presents an integer programming model and a computational tool for designing GSM (Global System for Mobile Communications) networks, regarding BSS (Base Station Subsystem) with optimized cost.

  19. A generalized transmultiplexer and its application to mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Ichiyoshi, Osamu

    1990-01-01

    A generalization of digital transmultiplexer technology is presented. The proposed method can realize transmultiplexer (TMUX) and transdemultiplexer (TDUX) filter banks whose element filters have bandwidths greater than the channel spacing frequency. This feature is useful in many communications applications. As an example, a satellite switched (SS) Frequency Division Multiple Access (FDMA) system is proposed for spot beam satellite communications, particularly for mobile satellite communications.

  20. Department of Mobile Communications Campus SophiaTech

    E-print Network

    Gesbert, David

    for periodic vehicular safety communications. Index Terms LTE-Direct, broadcast, eMBMS, periodic vehicular Communications eMBMS evolved Multimedia Broadcast Multicast Service eNB evolved Node B FDD Frequency DivisionEURECOM Department of Mobile Communications Campus SophiaTech 450 Route des Chappes 06410 Biot

  1. Simulation studies of the effects of user mobility on the handoff performance of mobile communications

    Microsoft Academic Search

    Kyungsook Han

    2002-01-01

    The performance of soft handoffs of code division multiple access (CDMA) mobile communication systems is determined by several factors. Due to the importance of handoffs in mobile communications, several handoff methods have been proposed and evaluated through computer simulations. However, the credibility of simulation results depends on the objectivity of the assumptions made by the simulations. This paper presents a

  2. Synchronisation and Timing Groups for GSM Networks

    Microsoft Academic Search

    Maxim Gitlits; Jackson Yin; Paul Kubik

    2006-01-01

    GSM networks are optimised for voice services using compact frequency re-use schemes such as 1\\/1 with fractional loading. GPRS\\/EDGE codecs require better quality channels to support higher data throughput, i.e. channels with lower collision rates and better average carrier-to-interference ratio (CII). With the continuing growth of mobile data traffic, networks must improve channel quality in a compact re-use environment. To

  3. Quality of Service Evaluation for Mobile Internet Access via the General Packet Radio Service (GPRS)

    Microsoft Academic Search

    Martin Adams; Michael Meyer; Joachim Sachs

    1998-01-01

    The General Packet Radio Service (GPRS) is an extension of the Global System for Mobile Communications (GSM) designated to support packet- oriented data transmission. GPRS will allow a much better access to the Internet compared to existing circuit switched bearer services. This paper investigates the influence of certain parameters on the Quality of Service GPRS can offer to mobile users.

  4. Mobile communications satellite antenna flight experiment definition

    NASA Astrophysics Data System (ADS)

    Freeland, Robert E.

    There are classes of application that collectively require a variety of different types of large-aperture space antennas. Fortunately, there are a number of different deployable antenna concepts that have tremendous potential for such applications. However, these concepts vary in maturity from flight-proven designs to extremely innovative configuration definitions. But these promising concepts lack sufficient demonstrations of maturity to be seriously considered in the large size range for immediate application. The reason for this situation is an extremely limited space flight data base in addition to the technical limitations and great costs associated with meaningful ground testing of large, flexible, precision space structures. The user community of such structures, especially the commercial organizations interested in providing a Mobile Communications Satellite (MSAT) on a profit-making basis, will require significant demonstrations of technology readiness prior to application commitment. Such demonstrations will probably be based on a combination of extensive ground testing and subsequent space flight experiments. The Communications Division of the National Aeronautics and Space Administration (NASA) Office of Space Science and Applications sponsored a study at the Jet Propulsion Laboratory (JPL) to determine the technical feasibility and cost of a Shuttle-based flight experiment specifically intended for the MSAT commercial user community. The experiment will include demonstrations of technology in the areas of radio frequency (RF), sensing and control, and structures. This paper summarizes the results of the structural subsystem study. These results include experiment objective and technical approach, experiment structural description, structure/environment interactions, structural characterization, thermal characterization, structural measurement system, and experiment functional description.

  5. 78 FR 69018 - Improving the Resiliency of Mobile Wireless Communications Networks; Reliability and Continuity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ...FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 4 [PS Docket...the Resiliency of Mobile Wireless Communications Networks; Reliability and Continuity of Communications Networks, Including Broadband...

  6. Secure Communication and Access Control for Mobile Web Service Provisioning

    E-print Network

    Srirama, Satish Narayana

    2010-01-01

    It is now feasible to host basic web services on a smart phone due to the advances in wireless devices and mobile communication technologies. While the applications are quite welcoming, the ability to provide secure and reliable communication in the vulnerable and volatile mobile ad-hoc topologies is vastly becoming necessary. The paper mainly addresses the details and issues in providing secured communication and access control for the mobile web service provisioning domain. While the basic message-level security can be provided, providing proper access control mechanisms for the Mobile Host still poses a great challenge. This paper discusses details of secure communication and proposes the distributed semantics-based authorization mechanism.

  7. Bandwidth Efficient Turbo Coding For High Speed Mobile Satellite Communications

    Microsoft Academic Search

    Mark Rice; Paul Gray; S. Adrian Barbulescu; Wade Farrell

    1997-01-01

    ABSTRACT This paper describes an application of turbo codes in conjunction with 16QAM in high speed mobile satellite communications The channel characteristics, the architecture of the modem and the performance curves for the selected turbo codes are presented

  8. Podscanning : audio microcontent and synchronous communication for mobile devices

    E-print Network

    Wheeler, Patrick Sean

    2010-01-01

    Over the past decade, computationally powerful audio communication devices have become commonplace. Mobile devices have high storage capacity for digital audio, and smartphones or networked PDAs can be used to stream ...

  9. Dimensioning of communication links for base-station and MSC interconnection in CDMA mobile communication systems

    Microsoft Academic Search

    Khaled M. F. Elsayed

    1997-01-01

    In CDMA mobile communication systems, voice is encoded and packaged in variable length packets that are transported between the mobile station and the switching center. While the packetization provides great flexibility in resource allocation, it poses a QOS challenge on voice. We discuss link dimensioning for a typical CDMA system. We consider a communication link connecting a CDMA base-station and

  10. Exposure to low level GSM 935 MHZ radiofrequency fields does not induce apoptosis in proliferating or differentiated murine neuroblastoma cells.

    PubMed

    Moquet, J; Ainsbury, E; Bouffler, S; Lloyd, D

    2008-01-01

    The aim of this study was to investigate whether radiofrequency (RF) fields characteristic of mobile phones at non-thermal levels can induce apoptosis in murine neuroblastoma (N2a) cells in both proliferating and differentiated states. Cells were exposed continuously for 24 h to one of the three 935-MHz RF signals: global system for mobile communication (GSM) basic, GSM talk and a continuous wave, unmodulated signal; all at a specific energy absorption rate of 2 W kg(-1). The measured increase in temperature of the cells due to the RF fields was around 0.06 degrees C. At a number of time points between 0 and 48 h post-exposure, the cells were assessed for apoptosis under a fluorescence microscope using three independent assays: Annexin V, caspase activation and in situ end-labelling. No statistically significant differences in apoptosis levels were observed between the exposed and sham-exposed cells using the three assays at any time point post-exposure. These data suggest that RF exposures, characteristic of GSM mobile phones, do not significantly affect the apoptosis levels in proliferating and differentiated murine neuroblastoma cell line N2a. PMID:18550513

  11. CURRENT DEGREE PROGRAMS GSM NON-DEGREE

    E-print Network

    Guenther, Frank

    CURRENT DEGREE PROGRAMS GSM NON-DEGREE Masters level coursework GSM 40 0000 A M.B.A. - MASTER OF BUSINESS ADMINISTRATION Business Administration & Management GSM 42 0506 A Health Sector Management GSM 42 0520 A Public Management GSM 42 0521 A SUBCONCENTRATIONS AVAILABLE TO M.B.A. CANDIDATES

  12. Near Field Communication and Bluetooth Bridge System for Mobile Commerce

    Microsoft Academic Search

    C. Y. Leong; K. C. Ong; K. K. Tan; O. P. Gan

    2006-01-01

    This paper presents an innovation of a Near Field Communication (NFC) and Bluetooth bridge system for connecting Bluetooth enabled mobile devices to NFC enabled consumer services. Nowadays, there is an abundance of mobile phones and PDAs with Bluetooth capability in the consumer market but there are fewer devices with NFC capability. In order for NFC enabled consumer services and payment

  13. Why young consumers are not open to mobile marketing communication

    Microsoft Academic Search

    Ian Grant

    2007-01-01

    This paper explores young people's motivations for using mobile phones. Older adoles- cents' everyday use of traditional and new forms of mediated communication were explored in the context of their everyday lives, with data generated from self-completion questionnaires, diaries and mini focus groups. The findings confirm the universal appeal of mobile phones to a youth audience. Social and entertainment-related motivations

  14. A Secure Authentication Infrastructure for Mobile Communication Services

    E-print Network

    von Bochmann, Gregor

    A Secure Authentication Infrastructure for Mobile Communication Services over the Internet Thesis everywhere, with various types of terminals, possibly mobile. In this thesis, we propose to secure for their cooperation and friendship. I think I should specially mention Khalil El-Khatib and Ronggong Song

  15. Cooperation without (reliable) communication: Interfaces for mobile applications

    Microsoft Academic Search

    Alan J. Dix

    1995-01-01

    The design of effective collaborative applications on mobile platforms has many problems. Wireless networks are fast enough that one aspires to true interactive applications, but too slow for much real-time feedback. This is exacerbated by the variability due to interference and broken connections. Mobile computing using wireless communications thus sits in a grey area between different styles of interaction. This

  16. Symbol grounding in communicative mobile robots IKAT / Infonomics -Universiteit Maastricht

    E-print Network

    Vogt, Paul

    a workable definition of a symbol. The implemented model is explained in the section called `language gamesSymbol grounding in communicative mobile robots Paul Vogt IKAT / Infonomics - Universiteit on an experiment in which two mobile robots solve the symbol grounding problem in a particular experimental setup

  17. Performance of CDMA mobile communication systems using antenna arrays

    Microsoft Academic Search

    Bruno Suard; Ayman F. Naguib; Guanghan Xu; Arogyaswami Paulraj

    1993-01-01

    The use antenna arrays in cellular code division multiple access mobile communications is studied. Techniques to localize each mobile within the cell and to generate tracking adaptive receive (and transmit) beams are addressed. The authors show that such enhancement of the CDMA system results in increased system capacity and improved robustness to power control errors. Preliminary simulation results are presented

  18. A secure network to connect (mobile) devices for interpersonal communication

    E-print Network

    Biagioni, Edoardo S.

    AllNet A secure network to connect (mobile) devices for interpersonal communication without Very little resources needed for text 140 characters for twitter, SMS A p2p network can support not secure PGP more effective if key exchange is improved Mobile devices in range of each other can

  19. An advanced system design for future global mobile satellite communications

    Microsoft Academic Search

    Hideo Okinaka; Yasuo Hirata

    1986-01-01

    This paper presents a system concept applicable to the future global mobile satellite communications system. The main features of the proposed system are a demand-assigned beam-hopping TDMA operation in the satellite-to-mobile direction and a demand-assigned SCPC operation in the mobile-to-satellite direction. A beam-hopping repeater configuration which does not require a dynamic switch between transmitters and a multiple spot beam antenna

  20. Evolving mobile communication practices of Irish teenagers

    Microsoft Academic Search

    Anthony Cawley; Deirdre Hynes

    2010-01-01

    Purpose – The purpose of this paper is to examine the social adoption of the mobile phone by Irish teenagers in city, town and rural settings. It aims to investigate two key areas that have influenced the teenagers' social adoption of the mobile phone: first, the influence of locational and socio-economic factors on mobile phone usage; second, how the teenagers'

  1. Frontiers of Wireless and Mobile Communications

    E-print Network

    Mandayam, Narayan

    applications as they migrate to mobile Internet platforms. KEYWORDS | Ad hoc and mesh networks; audiovisual Internet.[ The mobile Internet represents the second wave of the wireless revolution which started because of the popularity of Internet applications on mass-market mobile platforms including smart phones

  2. Efficient Perfectly Reliable and Secure Communication Tolerating Mobile Adversary

    E-print Network

    reliable communication from S to R tolerating a mobile adversary with arbitrary roaming speed3 . We show in the network. 3 By roaming speed we mean the speed with which the adversary changes the set of corrupted node 1" to each other via an underlying communication network that they do not trust. Note that if S and R

  3. Traffic Theory Approach for Heterogeneous Mobile Communication Networks

    Microsoft Academic Search

    Stephan Goebbels

    2007-01-01

    This paper presents a new traffic theory based approach for the analysis of heterogeneous wireless communication networks. While traffic theory is widely spread for the analysis of wired networks like the Internet the adaptation of these methods for wireless and especially heterogeneous networks is not yet accomplished. New upcoming mobile communication networks will be ruled by continuously switching radio access

  4. Quality Management using RFID and Third Generation Mobile Communications Systems

    Microsoft Academic Search

    Ng Hon; Wilton Fok; Edward Wong; Zongwei Luo

    2006-01-01

    Quality management, radio frequency identification (RFID) and third generation mobile communications systems (3G) are increasing attracting the attention of corporate managers. This paper illustrates the convergence of the three seemingly independent initiatives. RFID provides data inputs into the company's quality improvement systems, such as Six Sigma, while 3G supports realtime data communications between remote RFID devices and enterprise applications. RFID

  5. Mailbox-based scheme for mobile agent communications

    Microsoft Academic Search

    Jiannong Cao; Xinyu Feng; Jian Lu; Sajal K. Das

    2002-01-01

    In various situations, mobile agents at different hosts must cooperate with one another by sharing information and making decisions collectively. To ensure effective interagent communication, communication protocols must track target agent locations and deliver messages reliably. Researchers have proposed a wide range of schemes for agent tracking and reliable message delivery. However, each scheme has its own assumptions, design goals,

  6. Communication-aware surveillance in mobile sensor networks

    Microsoft Academic Search

    Alireza Ghaffarkhah; Yasamin Mostofi

    2011-01-01

    In this paper, we consider a surveillance problem, where a number of mobile nodes are tasked with surveying an area for the possible presence of stationary targets and reporting their findings back to a fixed base station, in the pres- ence of realistic fading communication channels. We develop a mathematical framework for robust communication-aware surveillance, in order to survey the

  7. Land mobile communications satellite mission (LAMOCOSAMIS) Task 1: Market study

    NASA Astrophysics Data System (ADS)

    1985-12-01

    Land mobile communication service demand in Europe and the Mediterranean basin in the years 1995-2005 was estimated. A traffic model was derived. There is an exploding demand for land mobile communications in Europe, with overwhelming preference for two way telephone services. The users survey shows a surprising lack of sensitivity to prices and tariffs, which widely contributed to the preeminence of the needs for telephone services. This demand justifies that every effort be made to develop as fast as possible a compatible pan-European terrestrial mobile system. If a large proportion of the needs may be satisfied by terrestrial mobile system solutions, the potential remaining needs for telephony, outside of the presently planned terrestrial mobile, which can be served only by satellite, even under the pessimistic economic scenario and high cost/tariff assumptions, requires a number of equivalent telephone circuits which cannot be achieved with available state of the art technology.

  8. Wireless communication for speech impaired subjects via portable augmentative and alternative system

    Microsoft Academic Search

    Hsiao-Yu Lee; Chih-Kuo Yeh; Chao-Min Wu; Mai-Feng Tsuang

    2001-01-01

    People with speech impairments are likely to also have varied movement disorders which result in the inability to use existing voice telephone facility. The aim of this research is to extend the current augmentative and alternative communication (AAC) system to wireless telecommunication service, for speech-impaired subjects. A pocket personal computer (PPC) with a Global System for Mobile Communications (GSM) module

  9. INTRODUCTION Future mobile communication systems will con-

    E-print Network

    will be cross-linked abundantly and provide a wider range of market. On one hand, with the usage of advanced developed with increasing spectrum band and data rate. On the other hand, future mobile networks are also- tecture and new technologies, such as mobility load balancing (MLB), for LTE networks [1, 2]. Driven

  10. Communicating Mobile Nano-Machines and Their Computational Power

    NASA Astrophysics Data System (ADS)

    Wiedermann, Ji?í; Petr?, Lukáš

    A computational model of molecularly communicating mobile nanomachines is defined. Nanomachines are modeled by a variant of finite-state automata—so-called timed probabilistic automata—augmented by a severely restricted communication mechanism capturing the main features of molecular communication. We show that for molecular communication among such motile machines an asynchronous stochastic protocol originally designed for wireless (radio) communication in so-called amorphous computers with static computational units can also be used. We design an algorithm that using the previous protocol, randomness and timing delays selects with a high probability a leader from among sets of anonymous candidates. This enables a probabilistic simulation of one of the simplest known model of a programmable computer—so-called counter automaton—proving that networks of mobile nanomachines possess universal computing power.

  11. Breaking GSM with rainbow Tables

    Microsoft Academic Search

    Steven Meyer

    2011-01-01

    Since 1998 the GSM security has been academically broken but no real attack has ever been done until in 2008 when two engineers of Pico Computing (FPGA manufacture) revealed that they could break the GSM encryption in 30 seconds with 200'000$ hardware and precomputed rainbow tables. Since then the hardware was either available for rich people only or was confiscated

  12. Mobile satellite communications systems: Toward global personal communications

    Microsoft Academic Search

    John H. Lodge

    1991-01-01

    The constraints imposed by the RF environment are reviewed. An overview of present and planned mobile satellite systems is given. Present systems refer to those already in operation, while planned systems refer to those that have authority to offer the services and have either a satellite in orbit or one being built to support the systems. Future directions for mobile

  13. Near Field Communication Technology: Contactless Applications in Mobile Environment

    Microsoft Academic Search

    Balázs Benyó

    StoLPaN, a pan-European consortium of companies, universities and user groups co-funded by the European Commission (EU), Information Society Technologies (IST) Programme aims to define open commercial and technical frameworks for the remote management of NFC-enabled (NFC: Near Field Communication) services on mobile devices. These frameworks will facilitate the deployment of NFC-enabled mobile applications across a wide range of vertical markets,

  14. High-speed satellite mobile communications: technologies and challenges

    Microsoft Academic Search

    MOHAMED IBNKAHLA; QUAZI MEHBUBAR RAHMAN; AHMED IYANDA SULYMAN; HISHAM ABDULHUSSEIN AL-ASADY; Jun Yuan; AHMED SAFWAT

    2004-01-01

    Central features of future 4G mobile communication systems are high-speed data transmission (up to 1 Gb\\/s) and interactive multimedia services. For effective delivery of these services, the network must satisfy some stringent QoS metrics, defined typically in terms of maximum delay and\\/or minimum throughput. Mobile satellite systems will be fully integrated with the terrestrial cellular systems to provide ubiquitous global

  15. Convergence of Mobile Communications and Broadcasting: A long term perspective

    Microsoft Academic Search

    Friedrich K. Jondral; Dennis Burgkhardt; Jens Elsner; Arnold Picot; Nico Grove

    Terrestrial unidirectional broadcasting is currently being substituted by wired bidirectional IP-based services. In practical day-to-day use, user mobility for the 'last mile' is supported by wireless local area networks with massively growing data rates. Terrestrial bidirectional mobile communications, on the other hand, is currently moving into its fourth technological generation. With the new UMTS Long Term Evolution (LTE) standards, data

  16. Reliable communication for mobile MANET-WSN scenarios

    Microsoft Academic Search

    Giuseppe Cardone; Antonio Corradi; Luca Foschini

    2011-01-01

    Advances in wireless communications have motivated the development of Wireless Sensor Networks (WSNs) for low-cost and easy-deployable physical and environmental monitoring. At the same time, the evolution of portable mobile devices is enabling novel fully integrated inter- network computing scenarios by making viable to opportunistically exploit Mobile Ad-hoc NETwork (MANET) devices traversing the WSN and equipped with a WSN radio

  17. Mobile small aperture satellite terminals for military communications

    Microsoft Academic Search

    Vijitha Weerackody; Lino Gonzalez

    2007-01-01

    The United States Army is currently developing a satellite-based network-centric waveform. Mobile terminals that are small and compact are highly desirable for the military. This article gives an overview of the technical challenges and performance issues when mobile small aperture satellite terminals are connected to a network- centric communication system. The specific issues addressed are regulatory limits on off-axis emissions,

  18. Biological aspects of mobile communication fields

    Microsoft Academic Search

    James C. Lin

    1997-01-01

    Our knowledge on the biological effects of RF radiation has been increasing for many decades. It has become a focus of attention because of the accelerated use of RF radiation for wireless communication over the past few years. It is fairly well established that at sufficiently high power levels, RF and microwave energy can produce deleterious biological effects. Wireless communication

  19. EHF satellite communication systems for mobile users

    Microsoft Academic Search

    R. E. Eaves

    1979-01-01

    The large amounts of spectrum available in the EHF and upper SHF region offer the potential to provide secure satellite communications to large numbers of users. However, the cost-effective realization of this potential requires the development of satellite communication system architectures which will serve small and relatively inexpensive terminals. Conventional transponder systems are inadequate both in the security they provide

  20. Enhancing Internet Service Security Using GSM SIM Authentication

    Microsoft Academic Search

    Do Van Thanh; Tore E. Jřnvik; Do Van Thuan; Ivar Jřrstad

    2006-01-01

    This paper describes thoroughly a service called SIM strong authentication which is aiming to provide strong and user-friendly authentication to the Internet Web services. The idea is to extend the usage of the current SIM authentication used in GSM to Internet Web services. The idea of making the mobile phone and its SIM card a universal authentication token is compelling

  1. Optimizing Frequency Hopping in GSM Cellular Phone Networks

    Microsoft Academic Search

    Jean-Marie Bourjolly; Souheyl Touhami; Leslie Déjoie; Ke Ding; Oumar Dioume; Michel Lominy

    2002-01-01

    The mobile telephony market has been undergoing a dramatic increase in the volume of demand as well as in the quality requirements. The limiting resource in this highly competitive market is the available frequency spectrum. In GSM networks, frequency reuse has been the basic tool for optimizing the spectrum management. This method is sometimes insufficient, however, for the most congested

  2. Single antenna interference cancellation (SAIC) for GSM networks

    Microsoft Academic Search

    Ayman Mostafa; Rich Kobylinski; Ivica Kostanic; Mark Austin

    2003-01-01

    This paper presents field trial results for downlink interference cancellation in a live GSM network. Uplink interference cancellation techniques have been developed in the past, which exploit the use of multiple receive antennas. However, downlink techniques are typically limited to just the use of a single receive antenna due to space limitations, cost considerations and aesthetics associated with current mobile

  3. A simple and compact tri-band planar inverted-F antenna for personal communication handset applications

    Microsoft Academic Search

    Fuguo Zhu; Chong Zhang; Jiadong Xu

    2009-01-01

    A simple and compact planar inverted-F antenna (PIFA) with size of 35 mm ?? 25 mm ?? 6 mm for personal communication handset applications is proposed in this paper. The radiating patch is folded at end and etched with two slits to create multiple resonant frequency bands. The antenna covers following frequency bands: Global System for Mobile communication (GSM900, 880-960

  4. Mobility Support in Real-time Video Communication UUUU

    Microsoft Academic Search

    Thomas C. Schmidt; Matthias Wählisch; Hans L. Cycon; Mark Palkow

    2003-01-01

    Mobile Internet devices recently gained much popu- larity and became widely available. Following an 802.11a\\/b or 3G standard they provide enough bandwidth to support data intensive communication services such as videoconferencing. Facing the emerging paradigm of ubiquitous computing and communication voice and videoconferencing over IP are on the spot to establish as standard Internet solutions. However, heavy infrastructural burdens and

  5. Design of a mobile coastal communications buoy

    E-print Network

    Hendry-Brogan, Meghan

    2004-01-01

    In response to a growing interest in networked communications at sea as well as the needs of our vital commercial fishing industry, the Northeast Consortium funded a novel research initiative to establish wireless acoustic ...

  6. WIRELESS COMMUNICATIONS MOBILE COMPUTING Wirel. Commun. Comput. 10.1002/wcm.1)

    E-print Network

    Giannakis, Georgios

    parameters instrumental in virtually aspects mobile communication system design. example, handoff initiationWIRELESS COMMUNICATIONS MOBILE COMPUTING Wirel. Commun. Comput. 10.1002/wcm.1) REVIEW Estima tion handoff algorithms and optimal tuning system parameters changing channel conditions adaptive transmission

  7. IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 15, NO. 8, OCTOBER 1997 1437 Mobile Location Management in ATM Networks

    E-print Network

    Veeraraghavan, Malathi

    incoming calls, data packets, and/or other services. In connection-oriented networks, mo- bility management, with minimal loss of user data). Since asynchronous transfer mode (ATM) networks are connection-oriented, both telephony networks are connection-oriented, the IS-41 and GSM MAP (mobility application part) standards [3

  8. A PCM-TDMA one dimensional mobile communication system using leaky coaxial cables

    Microsoft Academic Search

    Shoichiro Sakata; Tadao Saito; Hiroshi Inose

    1984-01-01

    In TDMA mobile communication systems, synchronization between a base station and mobile stations is a primary problem. This paper proposes a new mobile station synchronization scheme which does not require the propagation delay measurement or very long guard time for a one-dimensional mobile communication system using leaky coaxial cables (LCX). It shows that a large-capacity PCM-TDA mobile communication system can

  9. A satellite system for land-mobile communications in Europe

    NASA Astrophysics Data System (ADS)

    Bartholome, P.; Rogard, R.

    1988-05-01

    There exists a great unsatisified demand for land mobile communications in Europe, particularly in sectors of business activity such as the road transport industry. This demand could best be satisfied by means of satellite-based private networks providing voice and data communications in a hub configuration. The potential market is estimated to encompass several hundred thousand road vehicles and the transmission capacity required would be several thousand channels. ESA is currently demonstrating the potential of satellite communications for this type of application, using a system called PRODAT. System studies are being performed with the aim of defining the architecture of a regional satellite system for Europe.

  10. Global Mobility Management by Replicated Databases in Personal Communication Networks*

    E-print Network

    Leung, Kin K.

    [GPM92] has been established as an industry standard in the Global System for Mobile Telecommunication with industry protocol standards - and compare them with the traditional, centralized database scheme telecommunication services, such as Personal Communication and Software Defined Network (SDN) services, today

  11. Wireless Data Communication, Fall 03 Lecture 2. IP Mobility Support

    E-print Network

    Schwefel, Hans-Peter

    Wireless Data Communication, Fall 03 Lecture 2. IP Mobility Support Exercises 1. MIP Performance header bytes for Layer 3 and higher. The CN and the MH establish a bi-directional VoIP session (via UDP/IP network (assuming IP in IP tunneling)? o How does the latter change if minimal encapsulation is used

  12. Automated troubleshooting of a mobile communication network using Bayesian networks

    Microsoft Academic Search

    R. Barco; L. Nielsen; R. Guerrero; G. Hylander; S. Patel

    2002-01-01

    Operators of mobile communication networks face the challenging task of maintaining a complex network with thousands of cells. It requires highly skilled troubleshooting engineers to avoid a situation where subscribers are not properly served. This paper presents a new method for automating the troubleshooting task, thereby freeing a large portion of resources for other purposes. The method is described in

  13. Context-based remote security control for Mobile Communication Device

    Microsoft Academic Search

    Gaeil An; Daehee Seo; Jonghyun Kim; Kiyoung Kim; Dongil Seo

    2010-01-01

    Recently, as smartphone is becoming more and more popular, concern about security threats against Mobile Communication Device (MCD) is getting higher. The MCD can not only become the target of the cyber attacks, but also be used as the tool of the cyber attacks. This paper proposes a context-based remote security control scheme for MCD. The proposed scheme consists of

  14. Characteristics of early adopters in mobile communications markets

    Microsoft Academic Search

    Juha Munnukka

    2007-01-01

    Purpose – The purpose of this paper is to study consumers' adoption of mobile communications services, and to explore common denominators uniting those most likely to be early adopters; thereby, to help practitioners to predict early adoption and segment the market. Design\\/methodology\\/approach – Data were collected by postal questionnaire from 26 per cent of a sample of 3,000 customers of

  15. RF microelectronics for W-CDMA mobile communication systems

    Microsoft Academic Search

    A. Springer; R. Weigel

    2002-01-01

    Third generation (3G) mobile communication systems are now just at the beginning of their introduction. With a maximum data rate of 2 Mbps they will make wireless access to broadband data services like Internet or video applications feasible. Most of the different physical layer technologies summarized under the acronym 3G are based on Wideband - CDMA (W-CDMA) which is in

  16. Kalman filtering for power estimation in mobile communications

    Microsoft Academic Search

    Tao Jiang; Nicholas D. Sidiropoulos; Georgios B. Giannakis

    2003-01-01

    In wireless cellular communications, accurate local mean (shadow) power estimation performed at a mobile station is important for use in power control, handoff, and adaptive transmission. Window-based weighted sample average shadow power estimators are commonly used due to their simplicity. In practice, the performance of these estimators degrades severely when the window size deviates beyond a certain range. The optimal

  17. Channel-Individual Adaptive Beamforming for Mobile Satellite Communications

    Microsoft Academic Search

    Thomas Gebauer; Heinz G. Göckler

    1995-01-01

    A digital frequency-division multiplex demultiplexer for single channel per carrier (SCPC) signals was developed for use in a digital channel-individual beamforming network for an adaptive satellite array antenna for mobile satellite communications. The available ASIC (35000 gate functions in CMOS technology, clock rate up to 30 MHz with low power consumption) permits the separation of FDM signals comprising up to

  18. Multiservice on-board switching for mobile satellite communications

    Microsoft Academic Search

    L. Bella

    1988-01-01

    Future satellites for mobile communications will be required to interface ground ISDN (integrated services digital network) and to provide services and performances comparable with those offered by cellular radio networks. Onboard processing is a key technique to satisfy these requirements and can provide efficient integration with fixed satellite services. The European Space Agency (ESA) has started the development of a

  19. Using Mobile Communications to Assert Privacy from Video Surveillance

    Microsoft Academic Search

    Jack Brassil

    2005-01-01

    We propose a novel use of mobile communications to permit individuals to assert a preference for privacy from video surveillance. Our system, called Cloak, grants an individual the right to prohibit others from distributing video containing their image. We present our system architecture and operation, and demonstrate how the system enhances privacy while requiring no change to existing surveillance technology.

  20. Mobile communications system simulator development using structured analysis

    Microsoft Academic Search

    Jarno M. A. Tanskanen; Matti J. Rintamäki

    2001-01-01

    In this paper, structured analysis (SA) is employed in mobile communications system simulation software development. Programming via SA provides a well-defined and easily maintainable structure for the software in a graphical form, also revealing any hidden dependencies in the software. Thus, the resulting simulator is more reliable and maintainable over its whole lifecycle. With modern SA tools, documentation can be

  1. Model-based Security Analysis for Mobile Communications

    E-print Network

    Jurjens, Jan

    and use cases Abuse frames Security requirements Risk analysis External review Design Test plans Code Test results Field feedback Risk-based Security tests Static analysis (tools) Risk analysis Penetration testingModel-based Security Analysis for Mobile Communications Jan Jürjens1 , Jörg Schreck2 , Peter

  2. Future Directions for Mobile Communications Business, Technology and Research

    Microsoft Academic Search

    Juha Rapeli

    2001-01-01

    This paper presents a picture of the mobile communications market and expected further development of systems and technologies. This is done with evaluating the market needs and reflecting these to available technology as well as technological opportunities. Despite of apparently advanced state of the technology and business, both market and technical solutions are concluded to likely experience further radical changes.

  3. Accountable Anonymous Service Usage in Mobile Communication Systems \\Lambda

    E-print Network

    Bencsáth, Boldizsár

    Accountable Anonymous Service Usage in Mobile Communication Systems \\Lambda Levente Butty Abstract We introduce a model that allows of anonymous yet accountable service usage in mo­ bile revocable anonymity for users, which means that the identity of misbehaving users can be revealed. 1

  4. QoS management for the next mobile communication network

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Lu, Jun; Yu, Jianwei; He, Feng

    2004-04-01

    With convergence of network technologies, future network infrastructure will be based on IP and traditional wireless/mobile networks will also evolve inevitably to a unified all-IP mobile internet which can support voice, data and video simultaneously. But, the pattern served by IP is best effort. So IP mobility and QoS management have been the main challenges of all-IP mobile networks. Based on Mobile IP, IP QoS protocol, etc, ... The paper brings forward an end-to-end QoS management solution for the next mobile communication network, introduces a terminology of QoS Agent Server (QAS), which acts as resource manage server and participate in dynamic Service Level Specification (SLS) negotiation with mobile hosts (MH) or other QAS. Taking advantage of the mechanisms, discussed the process of QoS manage to support mobile hosts' fast handoff between cells. Additionally, adopted and self-adaptive control algorithm for non-real time service on interior nodes. Finally, conclusions are given and possible future works are described.

  5. Land-mobile satellite communication system

    NASA Technical Reports Server (NTRS)

    Yan, Tsun-Yee (Inventor); Rafferty, William (Inventor); Dessouky, Khaled I. (Inventor); Wang, Charles C. (Inventor); Cheng, Unjeng (Inventor)

    1993-01-01

    A satellite communications system includes an orbiting communications satellite for relaying communications to and from a plurality of ground stations, and a network management center for making connections via the satellite between the ground stations in response to connection requests received via the satellite from the ground stations, the network management center being configured to provide both open-end service and closed-end service. The network management center of one embodiment is configured to provides both types of service according to a predefined channel access protocol that enables the ground stations to request the type of service desired. The channel access protocol may be configured to adaptively allocate channels to open-end service and closed-end service according to changes in the traffic pattern and include a free-access tree algorithm that coordinates collision resolution among the ground stations.

  6. Coherent versus noncoherent signaling for satellite-aided mobile communications

    NASA Technical Reports Server (NTRS)

    Davarian, F.; Sumida, J.

    1986-01-01

    The use of coherent versus noncoherent communications is an unresolved issue for the mobile satellite community. Should one select the more robust but less efficient noncoherent strategy for communications over satellite-aided mobile channels, or does the introduction of a space platform in the mobile link improve signal stability (both amplitude and phase) such that conventional coherent schemes become attractive? This publication tries to answer some of the questions by discussing the results from experiments using a coherent QPSK receiver. The issues discussed include items such as the measured performance in Rician fading, the link error floor in a fading environment, etc. The results are compared and contrasted with that of a noncoherent limiter/discriminator FM receiver.

  7. Remote identification and information processing with a near field communication compatible mobile phone

    Microsoft Academic Search

    Raine Kelkka; Tommi Kallonen; Jouni Ikonen

    2009-01-01

    Mobile phones have become a popular platform for diverse applications in different fields. Near Field Communication (NFC), short range contactless communication standard developed especially for end user devices, is one the most novel technologies integrated into mobile phones. This paper presents a scenario where a Near Field Communication enabled mobile phone is used to identify a construction element, display information

  8. Breaking GSM with rainbow Tables

    E-print Network

    Meyer, Steven

    2011-01-01

    Since 1998 the GSM security has been academically broken but no real attack has ever been done until in 2008 when two engineers of Pico Computing (FPGA manufacture) revealed that they could break the GSM encryption in 30 seconds with 200'000$ hardware and precomputed rainbow tables. Since then the hardware was either available for rich people only or was confiscated by government agencies. So Chris Paget and Karsten Nohl decided to react and do the same thing but in a distributed open source form (on torrent). This way everybody could "enjoy" breaking GSM security and operators will be forced to upgrade the GSM protocol that is being used by more than 4 billion users and that is more than 20 years old.

  9. Integrating Communication, Computer Access, Environmental Control & Mobility.

    ERIC Educational Resources Information Center

    Romich, Barry A.; Vagnini, Carol B.

    Severely physically disabled people can be helped to reach their goals in educational, vocational, and personal pursuits through appropriate use of current technology. The expressive communication needs of people without functional speech can be met through an analysis of selection techniques, processing, and outputs. Examples of new systems…

  10. Analysis of a mobile communication security protocol

    Microsoft Academic Search

    Tom Coffey; Reiner Dojen

    2003-01-01

    Cryptographic protocols are used to achieve secure communication over insecure networks. Weaknesses in such protocols are hard to identify, as they can be the result of subtle design flaws. Formal verification techniques provide rigid and thorough means to evaluate security protocols. This paper demonstrates the process of formal verification by applying a logic to a security protocol intended for use

  11. Payload system tradeoffs for mobile communications satellites

    NASA Technical Reports Server (NTRS)

    Moody, H. J.

    1990-01-01

    System level trade-offs carried out during Mobile Satellite (M-SAT) design activities are described. These trade-offs relate to the use of low level beam forming, flexible power and spectrum distribution, and selection of the number of beams to cover the service area. It is shown that antenna performance can be improved by sharing horns between beams using a low level beam forming network (BFN). Additionally, greatly increased power utilization is possible using a hybrid matrix concept to share power between beams.

  12. The Globalstar mobile satellite system for worldwide personal communications

    NASA Astrophysics Data System (ADS)

    Wiedeman, Robert A.; Viterbi, Andrew J.

    Loral Aerospace Corporation along with Qualcomm Inc. have developed a satellite system which offers global mobile voice and data services to and from handheld and mobile user terminals with omni-directional antennas. By combining the use of low-earth orbit (LEO) satellites with existing terrestrial communications systems and innovative, highly efficient spread spectrum techniques, the Globalstar system provides users with low-cost, reliable communications throughout the world. The Globalstar space segment consists of a constellation of 48 LEO satellites in circular orbits with 750 NM (1389 km) altitude. Each satellite communicates with the mobile users via the satellite-user links and with gateway stations. The gateway stations handle the interface between the Globalstar network and the OSTN/PLMN systems. Globalstar transceivers are similar to currently proposed digital cellular telephones in size and have a serial number that will allow the end user to make and receive calls from or to that device anywhere in the world. The Globalstar system is designed to operate as a complement to existing local, long-distance, public, private and specialized telecommunications networks. Service is primarily designed to serve the rural and thin route communications needs of consumers, government users, and private networks.

  13. Compact mobile terminals for multi-beam mobile satellite communication systems

    NASA Astrophysics Data System (ADS)

    Sakai, Tsutomu; Komagata, Hitoshi; Terada, Noriyoshi; Hagiwara, Eiji

    Two types of compact mobile terminals for multibeam mobile satellite communications systems are described. One of them is designed for telephone service with 8-kb/s or 16-kb/s APC-AB (adaptive predictive coding-asynchronous binary) codecs or corresponding nontelephone services, such as facsimile; the other is for low-speed message service. For the 8-kb/s or 16-kb/s mobile terminal, an electronically steerable switched antenna technique, a digital signal processing technique, and custom LSIs are adopted to reduce equipment size. This terminal can be mounted on a small vessel or vehicle. For the message terminal, an omnidirectional antenna with a conically shaped radiation pattern is used, and its portability allows easy and instant communications anywhere at any time.

  14. Near field communication: getting in touch with mobile users.

    PubMed

    Hoy, Matthew B

    2013-01-01

    Near field communication is a method for sending and receiving small amounts of data across very short distances wirelessly. This technology is already available in a number of mobile devices and has many possible uses, including electronic payment, access control, and information exchange. This article will explain the basic principles of near field communication, discuss some of the ways it can be used in libraries, and explore some possible concerns with the technology. A list of resources for additional information is also included. PMID:23869639

  15. The design of static and mobile HF communication systems

    NASA Astrophysics Data System (ADS)

    Darnell, M.

    1986-03-01

    The lecture deals with more specific aspects of HF communication system design arising from a previous lecture entitled HF system design principles presented as part of AGARD Lecture Series 127 in 1983. The major topics considered are: (1) the design of point-to-point systems; (2) the design of systems involving mobile terminals; (3) system control and frequency management; (4) resistance to interception and disruption. The lecture is intended to provide a technical framework for later lectures covering the more detailed aspects of HF communication system design.

  16. Silicon integration of digital user-end mobile communication systems

    Microsoft Academic Search

    L. Philips; I. Bolsens; A. Rabaeijs; B. Vanhoof; J. Vanhoof; H. De Man

    1993-01-01

    An approach to single-chip integration of digital user-end mobile communication systems is presented. The characteristics of this class of DSP (digital signal processing) systems define the requirements of the proposed system architecture and system design environment. A distributed control approach has been chosen. The system design environment provides high-level system synthesis towards mixed architectural styles and silicon assembly in mixed

  17. Rayleigh fading compensation for QAM in land mobile radio communications

    Microsoft Academic Search

    Seiichi Sampei; Terumi Sunaga

    1993-01-01

    A pilot symbol-aided Rayleigh fading compensation is investigated for M-ary quadrature amplitude modulation (QAM) to achieve highly spectrally efficient land mobile communication systems. The optimum parameters for fading compensation, bit error rate (BER) performance against Eb\\/N0 (energy per bit to the noise power spectrum density), adjacent channel interference, and cochannel interference for 16-QAM, 64-QAM, and 256-QAM, and the spectral efficiencies

  18. Interference cancelling equalizer (ICE) for mobile radio communication

    Microsoft Academic Search

    Hitoshi Yoshino; Kazuhiko Fukawa; H. Sukuki

    1997-01-01

    This paper proposes an adaptive interference cancelling equalizer (ICE), which not only equalizes intersymbol interference (ISI), but also cancels cochannel interference (CCI) in the received signal in Rayleigh-fading environments, ICE is an adaptive multiuser detector for the frequency-selective fading environment commonly experienced by mobile communication channels. ICE employs a novel detection scheme: recursive least-squares maximum-likelihood sequence estimation (RLS-MLSE), which simultaneously

  19. Energy conservation in access protocols for mobile computing and communication

    Microsoft Academic Search

    I. Chlamtac; C. Petrioli; J. Redi

    1998-01-01

    Accelerating consumer interest and mushrooming applications for portable networked devices are driving the demand for the optimization of their functions and components. Porta-bility also necessitates reliance on small, self-contained and therefore limited-life power sources such as batteries, making power-management critical to a successful and wide-spread deployment of these new mobile devices. Meanwhile, commu-nications capabilities are fast becoming standard functions on

  20. A Jabber Based Framework for Building Communication Capable Java Mobile Applications

    Microsoft Academic Search

    Mohy Mahmoud; Sherif G. Aly; Ahmed Sabry; Mostafa Hamza

    2009-01-01

    The main aim of this framework and library is to provide Java Micro Edition developers a powerful mechanism that facilitates the process of building communication capable mobile applications. The framework enables mobile devices to abstractly exchange streams of data using an underlying communication infrastructure, and also supports the continued connectivity of mobile devices as they roam into different physical locations.

  1. Subjective performance evaluation of the GSM half-rate coding algorithm (with voice signals)

    Microsoft Academic Search

    Paolino Usai; G. Cosier; D. Pascal; J. Sotscheck; M. Kappelan

    1995-01-01

    The Pan-European cellular digital mobile radio system GSM uses a codec with a net bit rate of 13.0 kbit\\/s (gross bit rate including error protection 22.8 kbit\\/s), known as the “full rate” RPE-LTP (regular pulse excitation with long term prediction). GSM is now ready to dub channel capacity with the adoption of a new algorithm as an ETSI Recommendation, the

  2. Aeronautical Mobile Airport Communications System (AeroMACS)

    NASA Technical Reports Server (NTRS)

    Budinger, James M.; Hall, Edward

    2011-01-01

    To help increase the capacity and efficiency of the nation s airports, a secure wideband wireless communications system is proposed for use on the airport surface. This paper provides an overview of the research and development process for the Aeronautical Mobile Airport Communications System (AeroMACS). AeroMACS is based on a specific commercial profile of the Institute of Electrical and Electronics Engineers (IEEE) 802.16 standard known as Wireless Worldwide Interoperability for Microwave Access or WiMAX (WiMax Forum). The paper includes background on the need for global interoperability in air/ground data communications, describes potential AeroMACS applications, addresses allocated frequency spectrum constraints, summarizes the international standardization process, and provides findings and recommendations from the world s first AeroMACS prototype implemented in Cleveland, Ohio, USA.

  3. A secure application invocation mechanism in mobile phones for Near Field Communication

    Microsoft Academic Search

    Kwanghoon Choi; Jaekwon Kim; Seog Park

    2012-01-01

    This paper proposes an access control based, secure Near Field Communication in mobile phones. We make NFC tags hold codes of which the execution can make use of mobile services securely under user defined policies.

  4. Interference Analysis for an Aeronautical Mobile Airport Communications System

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Kercewski, Robert J.

    2010-01-01

    The next generation of aeronautical communications for airport surface applications has been identified through a NASA research program and an international collaborative future communications study. The result, endorsed by both the United States and European regulatory agencies is called AeroMACS (Aeronautical Mobile Airport Communications System) and is based upon the IEEE 802.16e mobile wireless standard. Coordinated efforts to develop appropriate aviation standards for the AeroMACS system are now underway within RTCA (United States) and Eurocae (Europe). AeroMACS will be implemented in a recently allocated frequency band, 5091- 5150 MHz. As this band is also occupied by fixed satellite service uplinks, AeroMACS must be designed to avoid interference with this incumbent service. The aspects of AeroMACS operation that present potential interference to the fixed satellite service are under analysis in order to enable the definition of standards that assure that such interference will be avoided. The NASA Glenn Research Center has been involved in this analysis, and the first results of modeling and simulation efforts directed at this analysis are the subject of this paper.12

  5. Interference Analysis for an Aeronautical Mobile Airport Communications System

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Kerczewski, Robert J.

    2011-01-01

    The next generation of aeronautical communications for airport surface applications has been identified through a NASA research program and an international collaborative future communications study. The result, endorsed by both the United States and European regulatory agencies is called AeroMACS (Aeronautical Mobile Airport Communications System) and is based upon the IEEE 802.16e mobile wireless standard. Coordinated efforts to develop appropriate aviation standards for the AeroMACS system are now underway within RTCA (United States) and Eurocae (Europe). AeroMACS will be implemented in a recently allocated frequency band, 5091-5150 MHz. As this band is also occupied by fixed satellite service uplinks, AeroMACS must be designed to avoid interference with this incumbent service. The aspects of AeroMACS operation that present potential interference to the fixed satellite service are under analysis in order to enable the definition of standards that assure that such interference will be avoided. The NASA Glenn Research Center has been involved in this analysis, and the first results of modeling and simulation efforts directed at this analysis are the subject of this presentation.

  6. Value in technology evolution: case mobile peer-to-peer communications

    Microsoft Academic Search

    Mikko V. J. Heikkinen; Sakari Luukkainen

    2010-01-01

    Purpose – Mobile peer-to-peer communications is an essential phase in the evolution of mobile communications technologies, motivating this research which aims to focus on how established industry stakeholders and new entrants can adapt themselves to the new situation. Design\\/methodology\\/approach – Based on existing literature, the authors identified three distinctive evolution paths for mobile peer-to-peer communications and developed an analysis framework

  7. The effect of pulsed 900-MHz GSM mobile phone radiation on the acrosome reaction, head morphometry and zona binding of human spermatozoa.

    PubMed

    Falzone, N; Huyser, C; Becker, P; Leszczynski, D; Franken, D R

    2011-02-01

    Several recent studies have indicated that radiofrequency electromagnetic fields (RF-EMF) have an adverse effect on human sperm quality, which could translate into an effect on fertilization potential. This study evaluated the effect of RF-EMF on sperm-specific characteristics to assess the fertilizing competence of sperm. Highly motile human spermatozoa were exposed for 1 h to 900-MHz mobile phone radiation at a specific absorption rate of 2.0 W/kg and examined at various times after exposure. The acrosome reaction was evaluated using flow cytometry. The radiation did not affect sperm propensity for the acrosome reaction. Morphometric parameters were assessed using computer-assisted sperm analysis. Significant reduction in sperm head area (9.2 ± 0.7 ?m˛ vs. 18.8 ± 1.4 ?m˛) and acrosome percentage of the head area (21.5 ± 4% vs. 35.5 ± 11.4%) was reported among exposed sperm compared with unexposed controls. Sperm-zona binding was assessed directly after exposure using the hemizona assay. The mean number of zona-bound sperm of the test hemizona and controls was 22.8 ± 12.4 and 31.8 ± 12.8 (p < 0.05), respectively. This study concludes that although RF-EMF exposure did not adversely affect the acrosome reaction, it had a significant effect on sperm morphometry. In addition, a significant decrease in sperm binding to the hemizona was observed. These results could indicate a significant effect of RF-EMF on sperm fertilization potential. PMID:20236367

  8. Low-cost S-band antennas for mobile satellite systems

    Microsoft Academic Search

    Cesar Dominguez; Ferdinando Tiezzi; Jose Padilla; Rainer Wansch; Rafael Rummel; Alexander Popugaev

    2011-01-01

    This paper presents the design of two low-cost multi- system omnidirectional antennas for mobile satellite communication systems. The antennas integrate the functionalities for the new S-band mobile satellite systems, the GPS and the GSM\\/UMTS bands. The first model includes an S- band Receive-Only radiating element for broadcasting applications and the second an S-band transmit-receive element for interactive services. The achieved

  9. Receiver synchronisation techniques for CDMA mobile radio communications based on the use of a priori information 

    E-print Network

    Vardoulias, George

    Receiver synchronisation can be a major problem in a mobile radio environment where the communication channel is subject to rapid changes. Communication in spread spectrum systems is impossible unless the received spreading ...

  10. Advanced mobile satellite communications using COMETS satellite in MM-wave and Ka-band

    NASA Technical Reports Server (NTRS)

    Ohmori, Shingo; Isobe, Shunkichi; Takeuchi, Makoto; Naito, Hideyuki

    1993-01-01

    Early in the 21st century, the demand for personal communications using mobile, hand-held, and VSAT terminals will rapidly increase. In a future system, many different types of services should be provided with one-hop connection. The Communications Research Laboratory (CRL) has studied a future advanced mobile satellite communications system using millimeter wave and Ka band. In 1990, CRL started the Communications and Broadcasting Engineering Test Satellite (COMETS) project. The satellite has been developed in conjunction with NASDA and will be launched in 1997. This paper describes the COMETS payload configuration and the experimental system for the advanced mobile communications mission.

  11. Advanced mobile satellite communications using COMETS satellite in MM-wave and Ka-band

    Microsoft Academic Search

    Shingo Ohmori; Shunkichi Isobe; Makoto Takeuchi; Hideyuki Naito

    1993-01-01

    Early in the 21st century, the demand for personal communications using mobile, hand-held, and VSAT terminals will rapidly increase. In a future system, many different types of services should be provided with one-hop connection. The Communications Research Laboratory (CRL) has studied a future advanced mobile satellite communications system using millimeter wave and Ka band. In 1990, CRL started the Communications

  12. Anonymous Authentication Protocols with Credit-Based Chargeability and Fair Privacy for Mobile Communications

    Microsoft Academic Search

    Chun-i Fan; Vincent Shi-ming Huang

    2007-01-01

    Smart and tiny mobile phones are widely popularized and advanced mobile communication services are provided increasingly such\\u000a that ubiquitous computing environments will come true soon. It is a pleasure for mobile users to work or get recreations in\\u000a the mobile network environments. However, just as the cases in wireline networks, there are many security threats to mobile\\u000a network systems and

  13. Radial microstrip slotline feed network for circular mobile communications array

    NASA Technical Reports Server (NTRS)

    Simons, Rainee N.; Kelly, Eron S.; Lee, Richard Q.; Taub, Susan R.

    1994-01-01

    In mobile and satellite communications there is a need for low cost and low profile antennas which have a toroidal pattern. Antennas that have been developed for mobile communications include a L-Band electronically steered stripline phased array, a Ka-Band mechanically steered elliptical reflector antenna and a Ka-Band printed dipole. In addition, a L-Band mechanically steered microstrip array, a L-Band microstrip phased array tracking antenna for mounting on a car roof and an X-Band radial line slotted waveguide antenna have been demonstrated. In the above electronically scanned printed arrays, the individual element radiates normally to the plane of the array and hence require a phase shifter to scan the beam towards the horizon. Scanning in the azimuth is by mechanical or electronic steering. An alternate approach is to mount microstrip patch radiators on the surface of a cone to achieve the required elevation angle. The array then scans in the azimuth by beam switching.

  14. Robust Timing Synchronization in Aeronautical Mobile Communication Systems

    NASA Technical Reports Server (NTRS)

    Xiong, Fu-Qin; Pinchak, Stanley

    2004-01-01

    This work details a study of robust synchronization schemes suitable for satellite to mobile aeronautical applications. A new scheme, the Modified Sliding Window Synchronizer (MSWS), is devised and compared with existing schemes, including the traditional Early-Late Gate Synchronizer (ELGS), the Gardner Zero-Crossing Detector (GZCD), and the Sliding Window Synchronizer (SWS). Performance of the synchronization schemes is evaluated by a set of metrics that indicate performance in digital communications systems. The metrics are convergence time, mean square phase error (or root mean-square phase error), lowest SNR for locking, initial frequency offset performance, midstream frequency offset performance, and system complexity. The performance of the synchronizers is evaluated by means of Matlab simulation models. A simulation platform is devised to model the satellite to mobile aeronautical channel, consisting of a Quadrature Phase Shift Keying modulator, an additive white Gaussian noise channel, and a demodulator front end. Simulation results show that the MSWS provides the most robust performance at the cost of system complexity. The GZCD provides a good tradeoff between robustness and system complexity for communication systems that require high symbol rates or low overall system costs. The ELGS has a high system complexity despite its average performance. Overall, the SWS, originally designed for multi-carrier systems, performs very poorly in single-carrier communications systems. Table 5.1 in Section 5 provides a ranking of each of the synchronization schemes in terms of the metrics set forth in Section 4.1. Details of comparison are given in Section 5. Based on the results presented in Table 5, it is safe to say that the most robust synchronization scheme examined in this work is the high-sample-rate Modified Sliding Window Synchronizer. A close second is its low-sample-rate cousin. The tradeoff between complexity and lowest mean-square phase error determines the rankings of the Gardner Zero-Crossing Detector and both versions of the Early-Late Gate Synchronizer. The least robust models are the high and low-sample-rate Sliding Window Synchronizers. Consequently, the recommended replacement synchronizer for NASA's Advanced Air Transportation Technologies mobile aeronautical communications system is the high-sample-rate Modified Sliding Window Synchronizer. By incorporating this synchronizer into their system, NASA can be assured that their system will be operational in extremely adverse conditions. The quick convergence time of the MSWS should allow the use of high-level protocols. However, if NASA feels that reduced system complexity is the most important aspect of their replacement synchronizer, the Gardner Zero-Crossing Detector would be the best choice.

  15. Registration Instructions for non-GSM Students: In order to apply for registration for a GSM class, you must

    E-print Network

    Lin, Xi

    Registration Instructions for non-GSM Students: In order to apply for registration for a GSM class permission is required for all non-GSM students enrolling in a GSM course. You may have the instructing1) or cohorted (X1 and X2) courses. You may only enroll in 2 GSM courses per semester. You may

  16. Registration Instructions for non-GSM Students: In order to register for a GSM class you must be an enrolled

    E-print Network

    Registration Instructions for non-GSM Students: In order to register for a GSM class you must is required for all non-GSM students enrolling in a GSM course. You may have the faculty member sign to verify your course schedule on the Student Link. Important notes: You may only enroll for 2 GSM courses

  17. Eavesdropping on GSM: state-of-affairs

    E-print Network

    Broek, Fabian van den

    2011-01-01

    In the almost 20 years since GSM was deployed several security problems have been found, both in the protocols and in the - originally secret - cryptography. However, practical exploits of these weaknesses are complicated because of all the signal processing involved and have not been seen much outside of their use by law enforcement agencies. This could change due to recently developed open-source equipment and software that can capture and digitize signals from the GSM frequencies. This might make practical attacks against GSM much simpler to perform. Indeed, several claims have recently appeared in the media on successfully eavesdropping on GSM. When looking at these claims in depth the conclusion is often that more is claimed than what they are actually capable of. However, it is undeniable that these claims herald the possibilities to eavesdrop on GSM using publicly available equipment. This paper evaluates the claims and practical possibilities when it comes to eavesdropping on GSM, using relatively che...

  18. A mobile trusted computing architecture for a near field communication ecosystem

    Microsoft Academic Search

    Gerald Madlmayr

    2008-01-01

    Near Field Communication (NFC) is a wireless communication technology to transfer data over distances of up to 10 cm. With this technology, a mobile device is capable of emulating smartcards for access, payment or loyalty. The benefits of a mobile device with NFC over an ordinary smartcard are the interaction and network capabilities of such a device. Thus there is

  19. 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.…

  20. Information communication scheme for loosely coupled mobile users in wireless sensor fields with multiple sources

    Microsoft Academic Search

    Euisin Lee; Fucai Yu; Min-Sook Jin; Sang-Ha Kim

    2009-01-01

    In wireless sensor networks, groups of mobile users interested in equivalent information could be classified into two categories according to existence of direct communication channel among the users: 1) loosely coupled user group and 2) tightly coupled user group. The loosely coupled group means that a mobile user should communicate with others via a wireless sensor network for querying, gathering,

  1. A new method of using preponderant terminal in cooperative satellite mobile communication system

    Microsoft Academic Search

    Jie Xiao; Feng Shaodong; Zhang Gengxin; Wang Fan

    2011-01-01

    In this paper, a new method of using pre- ponderant terminal in cooperative satellite mobile communication system was presented to reduce the influence of multipath fading and shading .First, the new method of using preponderant terminal in coopera- tive satellite mobile communication system was ana- lyzed?» then the system model was given and predi- gested to the typical three cooperative

  2. Stability and Control of Mobile Communications Systems With Time Varying Channels

    E-print Network

    Stability and Control of Mobile Communications Systems With Time Varying Channels Robert Buche, 2001 Abstract Consider the forward link of a mobile communications system with a single transmitter to the destination until transmitted. The main issues are the allocation of transmitter power and time to the various

  3. Stability and Control of Mobile Communications Systems With Time Varying Channels

    E-print Network

    Stability and Control of Mobile Communications Systems With Time Varying Channels Robert Buche Abstract Consider the forward link of a mobile communications system with a single transmitter and rather transmitted. The main issues are the allocation of transmitter power and time to the various queues in a queue

  4. A Joint Power and Subchannel Allocation Scheme Maximizing System Capacity in Indoor Dense Mobile Communication Systems

    Microsoft Academic Search

    Juyeop Kim; Dong-Ho Cho

    2010-01-01

    Indoor mobile communication systems (or simply indoor systems) are expected to yield significant improvement of capacity and coverage at low cost on mobile communication systems. However, the indoor system will likely be in dense environments, in which many cells exist in a small region, and a great portion of the coverage of a cell is overlapped by that of other

  5. Prediction of Fast Fading Mobile Radio Channels in Wideband Communication Systems

    E-print Network

    Dong, Liang

    , TX 78712 Abstract-- The fast fading mobile radio channels place fundamental limitationsPrediction of Fast Fading Mobile Radio Channels in Wideband Communication Systems Liang Dong. Introduction The radio channel in a wireless communication system is often characterized by multipath propa

  6. Rappaport, T. S., et al. "Mobile and Cellular Radio Communications" The Engineering Handbook.

    E-print Network

    Buehrer, R. Michael

    Rappaport, T. S., et al. "Mobile and Cellular Radio Communications" The Engineering Handbook. Ed. Richard C. Dorf Boca Raton: CRC Press LLC, 2000 © 1998 by CRC PRESS LLC #12;130 Mobile and Cellular Radio.4 Personal Communications System (PCS) 130.5 The Cellular Concept and System Fundamentals Frequency Reuse

  7. Energy-Efficient Wireless Communication based on Directional Transmission from Mobile Access

    E-print Network

    Zhong, Lin

    1 Energy-Efficient Wireless Communication based on Directional Transmission from Mobile Access 77025 Abstract The radio front-end (RF) is a major power consumer on mobile systems. In particularSwitch dynamically select the best antenna during active wireless transceiving without disrupting the communication

  8. Fireworks: An Adaptive Group Communications Protocol for Mobile Ad Hoc Networks

    E-print Network

    Krishnamurthy, Srikanth

    Fireworks: An Adaptive Group Communications Protocol for Mobile Ad Hoc Networks Lap Kong Law that move together. Thus, we develop Fireworks, an adaptive approach for group communications in mobile ad hoc networks. Fireworks is a hybrid two-tier multicast/broadcast pro- tocol that adapts to maintain

  9. Development of antenna system for S-band mobile satellite communications and broadcasting

    Microsoft Academic Search

    Ken-ichi Haryu; Yasuhiko Yamasa; Teruki Okamoto; Yuichi Otsu; Kazuhiko Yoneyama

    1996-01-01

    Advanced Space Communications Research Laboratory is studying an antenna system for future S-band mobile satellite communication and broadcasting. This system uses a GEO satellite and is composed of a large deployable satellite antenna with a 10 m diameter mesh reflector and a mobile antenna for vehicles and hand-held terminals. In this paper, we present our deployable satellite antenna program and

  10. Efficient simulation of TCP\\/IP for mobile wireless communications using importance sampling

    Microsoft Academic Search

    Zsolt Haraszti; J. Keith Townsend; James A. Freebersyser

    1998-01-01

    Future military communications systems are expected to exchange information in a seamless and reliable manner across heterogeneous networks composed of both fixed, wired nodes and mobile, wireless nodes. While commercial protocols such as TCP\\/IP have improved the seamlessness of military communications systems, the use of TCP\\/IP in the mobile, wireless environment for which it was not designed can have a

  11. Advanced interference rejection and anti-jam methods for low power mobile battlefield communications

    Microsoft Academic Search

    J. Scott Chuprun; Chad S. Bergstrom; Amy M. Guzek

    1997-01-01

    Mobile battlefield communication systems are called upon to operate effectively in increasingly adverse spectral environments. Obstacles to mobile battlefield communications include nonstationary command post co-site interference, ambient co-channel signals, and hostile jamming interferers. Typical interference levels encountered in a tactical environment can exceed the desired signal by 60 decibels. Such levels overwhelm the operational capabilities of current tactical radio systems.

  12. Designing a context-aware middleware for asynchronous communication in mobile ad hoc environments

    Microsoft Academic Search

    Mirco Musolesi

    2004-01-01

    In mobile ad hoc networks, synchronous communication mechanisms appear to be not suitable, since these assume that the involved entities are present at the same time during the interactions. On the other hand, asynchronous mechanisms seem to be better suited for mobile environments characterised with frequently intermittent connectivity. Therefore, message oriented middleware based on the asynchronous communication paradigm seems a

  13. Effect of user mobility on soft handoff performance in cellular communication

    Microsoft Academic Search

    Yali Qin; Xibing Xu; Ming Zhao; Yan Yao

    2002-01-01

    The handoff rate is a fundamental index to evaluate the handoff performance and as a result it affects the overall performance of a cellular mobile communication system. Meanwhile, moving patterns of mobiles are critical to the handoff rate. In this paper the effect of user's mobility on system handoff rate is studied The analytic result shows that the soft handoff

  14. Relation of user mobility to soft handoff rate in cellular communication

    Microsoft Academic Search

    Yali Qin; Xibing Xu; Ming Zhao; Yan Yao

    2002-01-01

    Handoff rate is a fundamental index to evaluate the handoff performance and as a result it affects the overall performance of cellular mobile communication system. Meanwhile, moving patterns of mobiles are critical to the handoff rate. In this paper the relation between user's mobility and system handoff rate is studied. The analytic result shows the soft handoff rate increases with

  15. Robotic Communication Terminals as a Mobility Support System for Elderly and Disabled People(2)

    NASA Astrophysics Data System (ADS)

    Yairi, Ikuko Eguchi; Igi, Seiji

    We have been developing Robotic Communication Terminals (RCT) as a mobility support system for the elderly and disabled people, which assists for their impaired elements of mobility— recognition, actuation, and information access. The RCT consist of three types of terminals: “environment-embedded terminal”“user-carried mobile terminal”, and “user-carrying mobile terminal”. These terminals communicate with one another to provide the users with a comfortable means of mobility. In this paper, we introduce the overview of our research. The recent progress is also presented as well as the future plan.

  16. Speech coding at 4800 bps for mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Gersho, Allen; Chan, Wai-Yip; Davidson, Grant; Chen, Juin-Hwey; Yong, Mei

    1988-01-01

    A speech compression project has recently been completed to develop a speech coding algorithm suitable for operation in a mobile satellite environment aimed at providing telephone quality natural speech at 4.8 kbps. The work has resulted in two alternative techniques which achieve reasonably good communications quality at 4.8 kbps while tolerating vehicle noise and rather severe channel impairments. The algorithms are embodied in a compact self-contained prototype consisting of two AT and T 32-bit floating-point DSP32 digital signal processors (DSP). A Motorola 68HC11 microcomputer chip serves as the board controller and interface handler. On a wirewrapped card, the prototype's circuit footprint amounts to only 200 sq cm, and consumes about 9 watts of power.

  17. Isolated and coupled superquadric loop antennas for mobile communications applications

    NASA Technical Reports Server (NTRS)

    Jensen, Michael A.; Rahmat-Samii, Yahya

    1993-01-01

    This work provides an investigation of the performance of loop antennas for use in mobile communications applications. The analysis tools developed allow for high flexibility by representing the loop antenna as a superquadric curve, which includes the case of circular, elliptical, and rectangular loops. The antenna may be in an isolated environment, located above an infinite ground plane, or placed near a finite conducting plate or box. In cases where coupled loops are used, the two loops may have arbitrary relative positions and orientations. Several design examples are included to illustrate the versatility of the analysis capabilities. The performance of coupled loops arranged in a diversity scheme is also evaluated, and it is found that high diversity gain can be achieved even when the antennas are closely spaced.

  18. Mobile tactical communications, the role of the UHF Follow-On satellite constellation and its successor, Mobile User Objective System

    Microsoft Academic Search

    J. Ingerski; A. Sapp

    2002-01-01

    The ultra high frequency (UHF) portion of the frequency spectrum is of great importance to the military for communications to the mobile warfighter. UHF has many advantages not available at other frequencies. UHF is used for both local line-of-site communications and worldwide military satellite communications (MILSATCOM). UHF Follow-On (UFO) is the satellite constellation used for narrowband MILSATCOM. UFO is used

  19. Mobile health-monitoring system through visible light communication.

    PubMed

    Tan, Yee-Yong; Chung, Wan-Young

    2014-01-01

    Promising development in the light emitting diode (LED) technology has spurred the interest to adapt LED for both illumination and data transmission. This has fostered the growth of interest in visible light communication (VLC), with on-going research to utilize VLC in various applications. This paper presents a mobile-health monitoring system, where healthcare information such as biomedical signals and patient information are transmitted via the LED lighting. A small and portable receiver module is designed and developed to be attached to the mobile device, providing a seamless monitoring environment. Three different healthcare information including ECG, PPG signals and HL7 text information is transmitted simultaneously, using a single channel VLC. This allows for a more precise and accurate monitoring and diagnosis. The data packet size is carefully designed, to transmit information in a minimal packet error rate. A comprehensive monitoring application is designed and developed through the use of a tablet computer in our study. Monitoring and evaluation such as heart rate and arterial blood pressure measurement can be performed concurrently. Real-time monitoring is demonstrated through experiment, where non-hazardous transmission method can be implemented alongside a portable device for better and safer healthcare service. PMID:25227066

  20. Evaluation of Ad-Hoc and Mobility Architectures using Satellite Communications

    E-print Network

    Paris-Sud XI, Université de

    Evaluation of Ad-Hoc and Mobility Architectures using Satellite Communications Thierry Gayraud1 introduce difficulties (canyons, mountains, vegetation...). In such scenarios, communications in a group may be done using ad-hoc networks principle, but the communications from one group to another can be compared

  1. Communication-Aware Surveillance in Mobile Sensor Networks Alireza Ghaffarkhah and Yasamin Mostofi

    E-print Network

    Mostofi, Yasamin

    Communication-Aware Surveillance in Mobile Sensor Networks Alireza Ghaffarkhah and Yasamin Mostofi to a fixed base station, in the pres- ence of realistic fading communication channels. We develop a mathematical framework for robust communication-aware surveillance, in order to survey the environment

  2. WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 00: 117 (20xx)

    E-print Network

    Paris-Sud XI, Université de

    communication primitives, that are iii) data dissemination via broadcasting/geocasting, and iv) routing in bothWIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 00: 1­17 (20xx) Communication Protocols for Vehicular Ad hoc Networks Arnaud Casteigts1 , Amiya Nayak1 , and Ivan Stojmenovic1 1

  3. Investigation of single-hop connections between user terminals in geostationary mobile satellite communication systems

    Microsoft Academic Search

    Kazuhito Ebina; Nobuyuki Kataoka; Masazumi Ueba; Hideki Mizuno

    2001-01-01

    The number of subscribers in geostationary mobile satellite communication systems has been increasing, as a result of the increase voice communication between user terminals. In this situation, there is a strong demand to improve the communication quality of the double-hop connection between two user terminals. As an means of reducing the voice delay, we developed four single-hop connection methods in

  4. DUAL STANDARD MOBILE HANDSETS FOR NEWS GATHERING

    Microsoft Academic Search

    J. D. Neale; E. V. Jones; J. T. Zubrzycki

    Remote news reporting via fixed telephones suffers from a lack of mobility and sound quality limitations. Options for the design of a GSM\\/DECT dual-standard mobile terminal for broadcast news gathering are presented. Simulation results show that GSM HSCSD could carry MPEG encoded audio and occasional pictures. Computer simulations demonstrate that a mean of 3 GSM channels (aggregate of 28.8kb\\/s) should

  5. Analysis of GSM\\/GPRS Cell with Multiple Data Service Classes

    Microsoft Academic Search

    K. Al-Begain; I. Awan; D. D. Kouvatsos

    2003-01-01

    This paper is concerned with the performance modelling and evaluationof a General Packet Radio Service (GPRS) for a wireless Global System forMobile telecommunication (GSM) cellinvolving both voice and multiple class data services under a completepartitioning scheme (CPS). The GPRS is modelled as a system ofaccess and transfer queues in tandem having an external multiple classcompound Poisson bursty traffic with geometrically

  6. A 18 mW triple 2 GHz CMOS PLL for 3G mobile systems with -113 dBc\\/Hz GSM in-band phase noise and dual-port GMSK modulation

    Microsoft Academic Search

    Mikael Guenais; StCphane Colomines; Hugues Beaulaton; Philippe Gorisse

    2003-01-01

    A PLL for 3G systems achieves -113-dBc\\/Hz close-in phase noise in the GSM Band and consumes 18 mW (2 mA for the 5 V charge-pump and 4mA under 1.875 Volts for the remaining blocks). The GMSK Dual-Port modulation system achieves 1.2° rms phase error and a noise level of -67dBc at 400 kHz offset from carrier in a 30 kHz

  7. A QoS guaranteed Mobile IP communication scheme with scalability in terms of resource management in backbone network

    Microsoft Academic Search

    Toshihiko KATO; Wei Liu; Seiji Ueno; Shuichi ITOH

    2003-01-01

    Resulting from the spread of the Mobile Internet, mobile communication with QoS guarantees will be required in order to realize mobile video interactions. So far, there are some studies which focused on QoS guaranteed Mobile IP communication, but they require backbone routers to maintain per flow QoS information for all individual mobile nodes. These approaches suffer from a lack of

  8. DESIRED MOBILE APPLICATION FEATURES IN AGRICULTURAL COMMUNICATIONS AND JOURNALISM STUDENTS AT TEXAS A&M UNIVERSITY 

    E-print Network

    Meadows, Casey

    2013-02-12

    Desired Mobile Application Features In Agricultural Communications And Journalism Students At Texas A&M University. (March 2013) Casey Meadows Department of Agriculture Texas A&M University Research Advisor: Dr. Billy McKim Department...

  9. A fast algorithm based on MEI and FMM for field prediction in urban mobile communications

    Microsoft Academic Search

    Xiaoxing Yin; Xinyu Zai; Wei Hong; Xiaowei Zhu

    1999-01-01

    To meet the growing demand for high-capacity mobile communication services, micro-cell and pico-cell are now introduced. The prediction of the wave propagation in urban micro- and pico-cells is becoming very important in the design of a mobile communication system. In urban environments with many high buildings, the antenna height at the base station is usually below the level of the

  10. Sales Communications in a Mobile World: Using the Latest Technology and Retaining the Personal Touch

    ERIC Educational Resources Information Center

    Norris, Daniel T.

    2007-01-01

    Salespeople increasingly have the opportunity to use technology to more quickly communicate with a larger number of clients and customers. Mobile technology, in particular, gives salespeople many advantages in rapidly reaching a large customer base. Furthermore, customers are increasingly employing mobile technology, making them increasingly…

  11. Dual-band omnidirectional microstrip patch array antenna for a mobile communication system

    Microsoft Academic Search

    T. Rutkowski; C. Peixeiro

    1997-01-01

    A dual-band omnidirectional microstrip patch antenna array is presented. The antenna will be used in the mobile terminal of a mobile communication system at 2 GHz. Four multilayer rectangular patches have been mounted on the sidewalls of a truncated pyramid. The main goal is to provide a received power as constant as possible along a typical elongated rectangular street cell

  12. WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2010; 10:547558

    E-print Network

    Jiang, Hai

    because of the time-varying network topology and propagation loss between any two nodes. QoS support access in an orderly manner among the mobile nodes such that efficiency can be achieved. Here, we focusWIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2010; 10:547­558 Published

  13. The relationship between mobile and fixed-line communications: A survey

    Microsoft Academic Search

    Ingo Vogelsang

    2010-01-01

    The dramatic worldwide increase in mobile communication that has led to more than 4 billion users has over the last few years been accompanied in wealthy countries by a significant decline in fixed network subscriptions. Such fixed-to-mobile substitution (FMS) is at the center of this literature survey. Theoretical models explaining FMS are scarce and are inconclusive regarding the balance between

  14. A New Paradigm for Mobile Multimedia Broadcasting Based on Integrated Communication and Broadcast Networks

    Microsoft Academic Search

    Zhisheng Niu; Long Long; Jian Song; Changyong Pan

    2008-01-01

    This article provides a new paradigm to integrate the Chinese digital television\\/terrestrial multimedia broadcasting (DTMB) systems with existing mobile communication systems, which can support mobile multimedia broadcasting services with carrier-grade quality. By dividing the services into four categories -digital TV, video on demand, data on demand, and Internet access - a complete design of the layered structure and signaling protocols

  15. The impact of digital iconic realism on anonymous interactants' mobile phone communication

    Microsoft Academic Search

    Sin-hwa Kang

    2007-01-01

    In this paper, I describe progress in research designed to explore the effect of the combination of behavioral and visual fidelity of avatars on users. social presence in synchronous and emotionally engaged mobile phone communication. I specifically focus on ways to secure mobile phone users. anonymity while preserving their most important nonverbal affective behaviors. The research measures social presence in

  16. Statistical characteristics of pedestrians' motion and effects on teletraffic of mobile communication networks

    Microsoft Academic Search

    Yuka Nagai; Takehiko Kobayashi

    2005-01-01

    Motion of mobile terminals greatly affects traffic characteristics (cell dwell time, handoff rates, channel occupancy lime of each base station, etc.) in mobile communication networks. Motion of vehicles was previously measured and characterized using the Global Positioning System, and its effects on traffic characteristics were examined. In this study, the authors measured pedestrian motion using an autonomous navigation system, analyzed

  17. IEEE Wireless Communications August 200466 1536-1284/04/$20.00 2004 IEEE Mobile station N

    E-print Network

    Shen, Xuemin "Sherman"

    IEEE Wireless Communications · August 200466 1536-1284/04/$20.00 © 2004 IEEE Mobile station N. In internetworking implementation, handoff performance should also be considered. Mobile IP handoff delay can approaches are actually only effective on registration signaling delays. For instance, a micro

  18. Impact of array processing techniques on the design of mobile communication systems

    Microsoft Academic Search

    V. A. N. Barroso; M. J. Rendas; J. P. Gomes

    1994-01-01

    Studies the application of adaptively steered arrays to mobile communications, particularly, in the design of base station antennas. System design issues are briefly reviewed on the basis of integration of those methods and the impact on transmitted power, co-channel reuse distance and spectrum efficiency is emphasized. Creating selective spatial channels enables to track the angular trajectory of each mobile and

  19. Rendering Adaptation to Address Communication and Computation Constraints in Cloud Mobile Gaming

    E-print Network

    California at San Diego, University of

    Rendering Adaptation to Address Communication and Computation Constraints in Cloud Mobile Gaming by the available server computing resource for each client, considering cloud server hosts numerous clients Shaoxuan Wang, Sujit Dey Mobile System Design Lab, Dept. of Electrical and Computer Engineering University

  20. Supporting terminal mobility by means of self-adaptive communication object migration

    Microsoft Academic Search

    Karin Anna Hummel; Szabolcs Póta; Christian Schusterreiter

    2005-01-01

    Mobile devices, like PDAs or smart phones, exhibit limited capabilities in terms of processing power and memory. Supported by advanced WLAN hotspot grid infrastructures, mobile terminals may enhance their computing capabilities significantly by utilizing remote resources in virtually shared spaces. Due to privacy and performance issues, the shared communication objects should be kept in proximity to the roaming owner which

  1. Mobile ad hoc networks for oceanic aircraft communications

    E-print Network

    Kingsbury, Ryan W

    2009-01-01

    Research into mobile ad hoc networks (MANET's) has exploded in recent years. MANET's are a type of wireless network in which independently mobile nodes are capable of self-forming and maintaining a connected network, even ...

  2. A Survey of Routing Techniques for Mobile Communications Networks

    Microsoft Academic Search

    S. Ramanathan; Martha Steenstrup

    1996-01-01

    . Mobile wireless networks pose interesting challenges for routing system design. To producefeasible routes in a mobile wireless network, a routing system must be able to accommodate roving users,changing network topology, and fluctuating link quality. We discuss the impact of node mobility and wirelesscommunication on routing system design, and we survey the set of techniques employed in or proposed forrouting

  3. Challenges of Digital Consumer and Mobile SoC's: More Moore Possible?

    Microsoft Academic Search

    Tohru Furuyama

    2007-01-01

    Digital consumer and mobile products have continuously accommodated more features and functions. For example, the recent high-end cellular phones can operate as terrestrial digital TV viewers, MP3 music players, digital cameras, substitutes of credit cards and many more in addition to multi-modal wireless communication terminals that handle various formats; GSM, 3G, BT, WiFi and so on. These products require to

  4. Challenges of Digital Consumer and Mobile SoC's: More Moore Possible?

    Microsoft Academic Search

    T. Furuyama

    2007-01-01

    Summary form only given. Digital consumer and mobile products have continuously accommodated more features and functions. For example, recent high-end cellular phones work as multi-modal wireless communicators that handle various formats; GSM, 3G, BT, WiFi and so on. In addition, they also operate as terrestrial digital TV viewers, MP3 music players, digital cameras, substitutes for credit cards, GPS locators and

  5. Keynote address: Challenges of digital consumer and mobile SoC's: more Moore possible?

    Microsoft Academic Search

    Tohru Furuyama

    2007-01-01

    Digital consumer and mobile products have continuously accommodated more features and functions. For example, the recent high-end cellular phones can operate as terrestrial digital TV viewers, MP3 music players, digital cameras, substitutes of credit cards and many more in addition to multi-modal wireless communication terminals that handle various formats; GSM, 3G, BT, WiFi and so on. These products require to

  6. SIMspeak - Towards an Open and Secure Application Platform for GSM SIMs

    Microsoft Academic Search

    Roger Kehr; Hendrik Mieves

    2001-01-01

    Today mobile operators are in the possession of the SIM application toolkit technology available in their GSM SIM smartcards\\u000a plugged into the mobile handsets of their subscribers. Although there are roughly 500 mio. SIMs deployed all over the world,\\u000a they are not integrated into the Internet yet. With the WebSIM approach [6] we have demonstrated how SIMs can be integrated

  7. GSM usage at the University of Ibadan

    Microsoft Academic Search

    Michael Wole Olatokun; Ibilola Oluseyi Bodunwa

    2006-01-01

    Purpose – The purpose of this study is to investigate the use of global system for mobile communications (GMS) at the University of Ibadan, Nigeria, emphasizing the nature and characteristics of the activities for which it is used, the factors that promote or beset its use, its benefits and the quality of services provided by the operators. Design\\/methodology\\/approach – The

  8. Using Mobile Communication Technology in High School Education: Motivation, Pressure, and Learning Performance

    ERIC Educational Resources Information Center

    Rau, Pei-Luen Patrick; Gao, Qin; Wu, Li-Mei

    2008-01-01

    Motivation and pressure are considered two factors impacting vocational senior high school student learning. New communication technology, especially mobile communication technology, is supposed to be effective in encouraging interaction between the student and the instructor and improving learning efficiency. Social presence and information…

  9. On the adaptability of LTE services in mobile satellite communications systems

    Microsoft Academic Search

    Xianghui Hu; Xiaohan Xia; Hongguang Lan; Jianjun Wu

    2012-01-01

    In this paper we mainly discuss the adaptability of LTE services in satellite communications systems. Four groups of LTE services are introduced, including the service aspects and transport requirements. Meanwhile several satellite systems are also listed in this paper. Based on these parameters and conditions, the adaptability of LTE services in mobile satellite communications systems is preliminarily discussed in terms

  10. An implementation of a CMA adaptive array for high speed GMSK transmission in mobile communications

    Microsoft Academic Search

    Takeo Ohgane; Takanori Shimura; Naoto Matsuzawa; Hideichi Sasaoka

    1993-01-01

    The hardware implementation of an adaptive array as a technique for compensating multipath fading in mobile communications is described. The number of the antenna elements is four. The target communication system is modulated by 256 kbps Gaussian-filtered minimum shift keying (MSK) and has a time-division multiplexing (TDM) architecture with 24 time slots. Based on the digital beamforming concept, all of

  11. Adaptive resource reservation schemes for proportional DiffServ enabled fourth-generation mobile communications system

    Microsoft Academic Search

    Chenn-jung Huang; Yi-ta Chuang; Wei Kuang Lai; Yu-hang Sun; Chih-tai Guan

    2007-01-01

    Many mechanisms based on bandwidth reservation have been proposed in the literature to decrease connection dropping probability for handoffs in cellular communications. The handoff events occur at a much higher rate in packet-switched fourth generation mobile communication networks than in traditional cellular systems. An efficient bandwidth reservation mechanism for the neighboring cells is therefore critical in the process of handoff

  12. Communication power optimization in a sensor network with a path-constrained mobile observer

    Microsoft Academic Search

    Arnab Chakrabarti; Ashutosh Sabharwal; Behnaam Aazhang

    2006-01-01

    We present a procedure for communication power optimization in a network of randomly distributed sensors with an observer (data collector) moving on a fixed path. The key challenge in using a mobile observer is that it remains within communication range of any sensor for a brief duration, and inability to transfer data in this duration leads to data loss. We

  13. Digital mobile communication system designed for nationwide police activities-WIDE system

    Microsoft Academic Search

    R. Inoue

    1996-01-01

    In 1991, the National Police Agency (NPA) of Japan introduced a new type of digital mobile communication system, called the WIDE system, as a countermeasure against nationwide criminal cases. The WIDE system uses an exclusive radio network for police use. This enables police officers to communicate with each other at any time, even if the public network channels are all

  14. The control system for smart home based on GSM and the radio

    Microsoft Academic Search

    Xu Yang; Lei Zhang; Jiasheng Sun

    2010-01-01

    In order to guarantee the effective control to the appliances and ensure the safety of living environment, a control system for smart home has been designed. Based on the GSM network service and wireless communication, the system is developed with the MCU AVR mega 16 as the core. It can be divided into two working patterns: the long-distance pattern and

  15. A PCM-TDMA one dimensional mobile communication system using leaky coaxial cables

    NASA Astrophysics Data System (ADS)

    Sakata, S.; Saito, T.; Inose, H.

    1984-10-01

    In TDMA mobile communication systems, synchronization between a base station and mobile stations is a primary problem. This paper proposes a new mobile station synchronization scheme which does not require the propagation delay measurement or very long guard time for a one-dimensional mobile communication system using leaky coaxial cables (LCX). It shows that a large-capacity PCM-TDA mobile communication system can be realized based on the proposed synchronization scheme, and describes an application method for the train mobile communication system. Mobile station synchronization scheme, signal transmission system, and synchronization scheme between base stations are described. On the estimation of the attainable bit rate from the physical environment of the transmission paths, the required guard time length and the optimum burst length are determined, and the frame structure and the channel control method are described. To demonstrate the feasibility of the system, a signal transmission experiment using an LCX at the estimated maximum bit rate has been carried out and the possibility of high-speed pulse transmission by means of LCX has been confirmed.

  16. A communication theoretical analysis of FRET-based mobile ad hoc molecular nanonetworks.

    PubMed

    Kuscu, Murat; Akan, Ozgur B

    2014-09-01

    Nanonetworks refer to a group of nanosized machines with very basic operational capabilities communicating to each other in order to accomplish more complex tasks such as in-body drug delivery, or chemical defense. Realizing reliable and high-rate communication between these nanomachines is a fundamental problem for the practicality of these nanonetworks. Recently, we have proposed a molecular communication method based on Förster Resonance Energy Transfer (FRET) which is a nonradiative excited state energy transfer phenomenon observed among fluorescent molecules, i.e., fluorophores. We have modeled the FRET-based communication channel considering the fluorophores as single-molecular immobile nanomachines, and shown its reliability at high rates, and practicality at the current stage of nanotechnology. In this study, for the first time in the literature, we investigate the network of mobile nanomachines communicating through FRET. We introduce two novel mobile molecular nanonetworks: FRET-based mobile molecular sensor/actor nanonetwork (FRET-MSAN) which is a distributed system of mobile fluorophores acting as sensor or actor node; and FRET-based mobile ad hoc molecular nanonetwork (FRET-MAMNET) which consists of fluorophore-based nanotransmitter, nanoreceivers and nanorelays. We model the single message propagation based on birth-death processes with continuous time Markov chains. We evaluate the performance of FRET-MSAN and FRET-MAMNET in terms of successful transmission probability and mean extinction time of the messages, system throughput, channel capacity and achievable communication rates. PMID:25014963

  17. TDMA-Based Dual-Mode Communication for Mobile Wireless Sensor Networks

    PubMed Central

    Mehta, Ankur; Kerkez, Branko; Glaser, Steven D.; Pister, Kristofer S. J.

    2012-01-01

    Small highly mobile robots, and in particular micro air vehicles (MAVs), are well suited to the task of exploring unknown indoor environments such as buildings and caves. Such a task imposes a number of requirements on the underlying communication infrastructure, with differing goals during various stages of the mission. This work addresses those requirements with a hybrid communications infrastructure consisting of a stationary mesh network along with the mobile nodes. The combined network operates in two independent modes, coupling a highly efficient, low duty cycle, low throughput mode for routing and persistent sensing with a burst mode for high data rate communication. By strategically distributing available frequency channels between the mobile agents and the stationary nodes, the overall network provides reliable long-term communication paths while maximizing data throughput when needed. PMID:23443374

  18. 4308 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 6, NO. 12, DECEMBER 2007 Joint Scale-Lag Diversity in Wideband Mobile

    E-print Network

    Schniter, Philip

    -Lag Diversity in Wideband Mobile Direct Sequence Spread Spectrum Systems Adam R. Margetts, Member, IEEE, Philip of mobility on a wideband direct sequence spread spectrum (DSSS) communication system, and study a scale

  19. Geometrically based directional channel model for urban mobile communication systems

    Microsoft Academic Search

    Yasuhiro ODA; Koichi TSUNEKAWA; Masaharu HATA

    2000-01-01

    This paper proposes a geometrically based propagation model for an urban mobile environment that establishes a relationship between the angle-of-arrival and time-of-arrival of multipath components. The model is characterized by the geometric locations of a base station and mobile station among urban city structures. This model comprises three sets of propagation characteristics: the street-microcell propagation characteristics around mobile stations; the

  20. On the design of security protocols for mobile communications

    Microsoft Academic Search

    Yi Mu; Vijay Varadharajan

    1996-01-01

    . Use of mobile personal computers in open networked environmentis revolutionalising the way we use computers. Mobile networkedcomputing is raising important information security and privacy issues.This paper is concerned with the design of authentication protocols fora mobile computing environment. The paper first analyses the authenticationinitiator protocols proposed by Beller,Chang and Yacobi (BCY)and the modifications considered by Carlsen and points out

  1. Reliable Real-Time Communication in Cooperative Mobile Applications

    E-print Network

    independent communication part that constitutes the real-time and reliability hardcore of the system and timely to the group of cooperating systems. It is based on the communication hardcore, which provides, the development of the communication hardcore is the most challenging task. On the one hand, to be usable

  2. Wireless Communications

    NSDL National Science Digital Library

    Leske, Cavin.

    Wireless communications is an industry that is growing at an incredible rate. Cellular phones are the most obvious example of this trend; it is hard to go anywhere without seeing someone using one. Rapidly advancing technologies and lower prices are making this all possible. At the current pace, there seems to be no limit to what is possible in the wireless industry.To learn about the events that led up to present day wireless communications, this site offers a very informative history of telecommunications (1) that goes all the way back to the time of carrier pigeons. A good introduction to wireless networking can be found in this mini-tutorial (2). The best parts of this tutorial are the discussions of many recent wireless developments and technologies. There are a few interactive games and activities that are supposed to be instructive and entertaining, but some of them can be annoying. For the more technically savvy user, the third site (3) starts by describing many of the principles that drive current wireless systems. The second part examines the technologies that will be used in future generations of services. To build on this material, the third generation mobile communications systems (3G) is the central topic at 3G Newsroom (4), providing breaking news about the development of 3G technology. Additionally, the site has an excellent introduction to 3G, including its applications and specifications. One of the advancements that is paving the way toward 3G is Bluetooth, which is explained in great detail here (5). This technology is capable of very high data transfer rates, but there are some limitations, which are all discussed in the articles on the site. Although Bluetooth is raising plenty of interest, this recent news story (6) is creating more than its share of debate. It outlines a very controversial move by the FCC to allow the use of ultrawideband technology in commercial wireless applications. The author explains in simple terms why there are so many concerns about something that could revolutionize wireless systems. The evolution of the global system for mobile communications (GSM) is traced at GSM World (7). Here users can learn about the roots of the wireless industry as well as what is in store for the future. A special section addresses health concerns associated with mobile phone use. Radio was one of the earliest form of wireless communication, and the Invention of Radio (8) documents the people and events that made it what it is today. The stories of such famous scientists and inventors as Marconi, DeForest, and Armstrong are told in brief accounts, and there is even a link to the well known War of the Worlds radio broadcast.

  3. Unsupervised User Similarity Mining in GSM Sensor Networks

    PubMed Central

    Shad, Shafqat Ali; Chen, Enhong

    2013-01-01

    Mobility data has attracted the researchers for the past few years because of its rich context and spatiotemporal nature, where this information can be used for potential applications like early warning system, route prediction, traffic management, advertisement, social networking, and community finding. All the mentioned applications are based on mobility profile building and user trend analysis, where mobility profile building is done through significant places extraction, user's actual movement prediction, and context awareness. However, significant places extraction and user's actual movement prediction for mobility profile building are a trivial task. In this paper, we present the user similarity mining-based methodology through user mobility profile building by using the semantic tagging information provided by user and basic GSM network architecture properties based on unsupervised clustering approach. As the mobility information is in low-level raw form, our proposed methodology successfully converts it to a high-level meaningful information by using the cell-Id location information rather than previously used location capturing methods like GPS, Infrared, and Wifi for profile mining and user similarity mining. PMID:23576905

  4. A shortest path algorithm for mobile satellite communication network

    Microsoft Academic Search

    Zhang Tao; Zhang Jun; Liu Zhong Kan

    2005-01-01

    Mobile satellite network is a special time-varying network. Some classical network theories used in the current terrestrial networks, such as the shortest path algorithm, cannot be applied to it availably. In this paper, based on the proposed model of mobile satellite network, the classical shortest path algorithm of fixed topological network, such as the Dijkstra algorithm, is proved to be

  5. Multimodal biometric authentication using quality signals in mobile communications

    Microsoft Academic Search

    Josef Bigün; Julian Fiérrez-aguilar; Javier Ortega-garcia; Joaquin Gonzalez-rodriguez

    2003-01-01

    The elements of multimodal authentication along with system models are presented. These include the machine experts as well as machine supervisors. In particular finger- print and speech based systems will serve as illustration of a mobile authentication application. A novel signal adap- tive supervisor, based on the input biometric signal quality is evaluated. Experimental results on data collected from mobile

  6. Alternative metrics for hard handoffs in mobile communication

    Microsoft Academic Search

    Raymond M. Bendett; Perambur S. Neelakanta

    2000-01-01

    Handoff (or handover) refers to a crucial effort by a particular mobile unit to change from its serving base station to another as warranted by dynamic variations in link quality caused by mobility and interference\\/fading considerations. Classically, the handover initiation is done by a decision algorithm based on received signal strengths (RSSs) from the serving and prospective base stations. That

  7. Secure Positioning of Mobile Terminals with Simplex Radio Communication

    Microsoft Academic Search

    Mikio Fujii

    2006-01-01

    With the rapid spread of various mobile terminals in our society, the importance of secure position- ing is growing for wireless networks in adversarial settings. Recently, several authors have proposed a secure positioning mechanism of mobile terminals which is based on the geometric property of wire- less node placement, and on the postulate of mod- ern physics that a propagation

  8. Laser Communication Demonstration System (LSCS) and Future Mobile Satellite Services

    NASA Technical Reports Server (NTRS)

    Chen, C. -C.; Lesh, J. R.

    1995-01-01

    The Laser Communications Demonstration System (LCDS) is a proposed in-orbit demonstration of high data rate laser communications technology conceived jointly by NASA and U.S. industry. The program objectives are to stimulate industry development and to demonstrate the readiness of high data rate optical communications in Earth Orbit. For future global satellite communication systems using intersatellite links (ISLs), laser communications technology can offer reduced mass , reduced power requirements, and increased channel bandwidths without regulatory restraint. This paper provides comparisons with radio systems and status of the program.

  9. Stochastic differential equations for modeling, estimation and identification of mobile-to-mobile communication channels

    Microsoft Academic Search

    Mohammed M. Olama; Seddik M. Djouadi; Charalambos D. Charalambous

    2009-01-01

    Mobile-to-mobile networks are characterized by node mobility that makes the propagation environment time varying and subject to fading. As a consequence, the statistical characteristics of the received signal vary continuously, giving rise to a Doppler power spectral density (DPSD) which varies from one observation instant to the next. The current models do not capture and track the time varying characteristics.

  10. [Pilot plan for a mobile health communication and monitoring system for people with diabetes].

    PubMed

    Alcayaga, Claudia; Pérez, Janet Carola; Bustamante, Claudia; Campos, Solange; Lange, Ilta; Zuńiga, Francisca

    2014-01-01

    mHealth is a practical, useful, and available tool for one-way or two-way communication between health professionals and patients. It is especially promising in countries such as Chile, with widespread and growing mobile telephone coverage that is very well accepted by the public. Our objective is to demonstrate the process for designing a mobile communication and monitoring model, aimed at providing communication between professionals in primary healthcare centers and their patients, to facilitate timely diagnosis and initiation of treatment for type 2 diabetes. This model's characteristics include use of mobile telephones as a communication tool, a one-way method (from health centers to patients), integration into in-person care delivered at health centers, use of different communication strategies (voice and written), and integrated functioning using open-source software. The system includes personalized communication, automated voice communication, and automated written communication using short message service (SMS). We describe the strategies and components of the system. The lessons learned include the contribution from successful implementation of COSMOS (consolidated online modulated operating systems), a technological innovation, to support the health care of people with suspected type 2 diabetes in primary healthcare centers. Working together with teams in the field is essential to this achievement. PMID:25211577

  11. Mobile Networks and Applications 2 (1997) 285301 285 Communication protocol design to facilitate re-use based on the

    E-print Network

    Khan, Javed I.

    1997-01-01

    formal descriptions for communication protocols and the effective development methodologies usedMobile Networks and Applications 2 (1997) 285­301 285 Communication protocol design to facilitate varying error rates. Similarly, handoff procedures create situations where dynamically determined change

  12. Battery consumption and handoff examination of a cellular ad-hoc united communication system for operational mobile robots

    Microsoft Academic Search

    Tomoko Adachi; Masao Nakagawa

    1998-01-01

    A hybrid system in which mobile terminals (MTs) themselves select whether to communicate directly or via base stations (BSs) from communication conditions, “cellular ad hoc united communication system”, has been proposed by Adachi and Nakagawa (1996). It has been confirmed to have effective channel usage, especially for MTs which tend to communicate with partners which are close together, such as

  13. Communication satellite studies applicable to mobile telephone services

    NASA Technical Reports Server (NTRS)

    Anderson, R. E.; Milton, R. T.; Brown, J. P.

    1979-01-01

    The potential use of satellites as extensions of existing terrestrial land mobile systems is discussed. Compatibility, particularly with cellular type systems, is considered. Sample technical and cost parameters and market assessments are also presented.

  14. Automatic recloser circuit breaker integrated with GSM technology for power system notification

    NASA Astrophysics Data System (ADS)

    Lada, M. Y.; Khiar, M. S. A.; Ghani, S. A.; Nawawi, M. R. M.; Rahim, N. H.; Sinar, L. O. M.

    2015-05-01

    Lightning is one type of transient faults that usually cause the circuit breaker in the distribution board trip due to overload current detection. The instant tripping condition in the circuit breakers clears the fault in the system. Unfortunately most circuit breakers system is manually operated. The power line will be effectively re-energized after the clearing fault process is finished. Auto-reclose circuit is used on the transmission line to carry out the duty of supplying quality electrical power to customers. In this project, an automatic reclose circuit breaker for low voltage usage is designed. The product description is the Auto Reclose Circuit Breaker (ARCB) will trip if the current sensor detects high current which exceeds the rated current for the miniature circuit breaker (MCB) used. Then the fault condition will be cleared automatically and return the power line to normal condition. The Global System for Mobile Communication (GSM) system will send SMS to the person in charge if the tripping occurs. If the over current occurs in three times, the system will fully trip (open circuit) and at the same time will send an SMS to the person in charge. In this project a 1 A is set as the rated current and any current exceeding a 1 A will cause the system to trip or interrupted. This system also provides an additional notification for user such as the emergency light and warning system.

  15. Low cost Ku-band electronic steerable array antenna for mobile satellite communications

    Microsoft Academic Search

    Stefano Vaccaro; Daniel Llorens del Rio; Jose Padilla; Rens Baggen

    2011-01-01

    This paper presents the results of the development of an active phased array antenna for Ku-Band Receive-only mobile satellite communications realised within the ESA-project NATALIA. The phased array antenna is designed for mobile satellite services and dedicated for automotive applications. An overview of the complete build-up will be provided as well as the current status of the multilayer Printed Circuit

  16. Military communications satellite system multiplies UHF channel capacity for mobile users

    Microsoft Academic Search

    D. Wadsworth

    1999-01-01

    The mobile user objective system (MUOS) will be the successor to the Navy's UFO satellite communications system. One MUOS proposal relies on a constellation of GEO spacecraft that uses non-processing repeaters and multiple spotbeams for worldwide Earth-coverage. UHF frequency reuse greatly increases the number of narrowband voice\\/data channels available to mobile units. A key design element is the large antenna

  17. Smart low-power CMOS cameras for 3G mobile communicators

    Microsoft Academic Search

    M. Ansorge; S. Tanner; X. Shi; J. Bracamonte; J.-L. Nagel; P. Stadelmann; F. Pellandini; P. Seitz; N. Blanc

    2002-01-01

    The paper presents the concept of a smart multifunctional low-power camera for 3G mobile communicators and Personal Digital Assistants. The device is composed of an ultra low-power image sensor featuring a large intra-scene dynamic range and a high sensitivity, so as to ensure proper image acquisition under possibly severe illumination conditions, as encountered in mobile. Further embedded functionalities encompass low-power

  18. A model for local\\/mobile radio communications with correct packet capture

    Microsoft Academic Search

    R. Clark Robertson; Tri T. Ha

    1992-01-01

    The performance of a local\\/mobile radio communications system utilizing the slotted ALOHA multiple random access protocol is analyzed. The probability of correct packet capture is evaluated for a local\\/mobile packet radio system using ideal coherent binary phase-shift keying (BPSK) modulation. Both the near\\/far effect and the effect of Rayleigh fading on the probability of correct packet capture are taken into

  19. Cross layer design for mobile Ad-Hoc Unmanned Aerial Vehicle communication networks

    Microsoft Academic Search

    Abdel Ilah Alshbatat; Liang Dong

    2010-01-01

    A Mobile Ad-Hoc Network (MANET) is a popular type of wireless network that is formed by a collection of mobile nodes. Each node in such network has the capability to communicate with its neighbors and non-neighbors through a wireless medium without using any existing network infrastructure. Due to the lack of infrastructure, all nodes in Ad-Hoc network are designed to

  20. Delay-tolerant communication using mobile robotic helper nodes

    Microsoft Academic Search

    Daniel Henkel; Timothy X Brown

    2008-01-01

    Delay tolerant networks can exhibit long phases of complete unconnectedness, where several nodes will not be able to communicate effectively. In those circumstances controlling the movement of helper nodes, that facilitate message exchanges instead of relying on direct communication, can improve network performance. We investigate when controlled movement is beneficial and how helper nodes need to move or position themselves

  1. Modems for emerging digital cellular-mobile radio system

    NASA Astrophysics Data System (ADS)

    Feher, Kamilo

    1991-05-01

    Digital modem techniques for emerging digital cellular telecommunications-mobile radio system applications are described and analyzed. In particular, theoretical performance, experimental results, principles of operation, and various architectures of pi/4-QPSK (pi/4-shifted coherent or differential QPSK) modems for second-generation US digital cellular radio system applications are presented. The spectral/power efficiency and performance of the pi/4-QPSK modems (American and Japanese digital cellular emerging standards) are studied and briefly compared to GMSK (Gaussian minimum-shift keying) modems (proposed for European DECT and GSM cellular standards). Improved filtering strategies and digital pilot-aided (digital channel sounding) techniques are also considered for pi/4-QPSK and other digital modems. These techniques could significantly improve the performance of digital cellular and other digital land mobile and satellite mobile radio systems. More spectrally efficient modem trends for future cellular/mobile (land mobile) and satellite communication systems applications are also highlighted.

  2. [The role of mobile communication devices in the spread of infections].

    PubMed

    Morvai, Júlia; Szabó, Rita

    2015-05-17

    Mobile communication devices have an invaluable feature of communication within hospital, and they may support certain aspects of clinical diagnosis and education. However, there may be a risk for contamination of these devices with various pathogens. The aim of the authors was to perform a systematic review on the potential role of mobile communication devices in the dissemination of pathogens and to identify effective prevention measures. A detailed literature search was conducted using PubMed and ScienceDirect databases for papers published in English between January, 2004 and August, 2014. With the use of specific search term combinations 30 of the 216 articles met the inclusion criteria. It was found that only 8% of healthcare workers routinely cleaned their mobile communication devices resulting in a high rate of contamination (40-100%). Coagulase-negative Staphylococci and Staphylococcus aureus were the most commonly identified bacteria and most of them were methicillin resistant (10-95.3%). This systematic review identified effective interventions to reduce bacterial contamination risks including staff education, hand hygiene and regular decontamination of mobile communication devices. PMID:26038946

  3. The security of the GSM air interface Chris J. Mitchell

    E-print Network

    Dent, Alexander W.

    The security of the GSM air interface protocol Chris J. Mitchell Technical Report RHUL{MA{2001{3 18 This paper describes the level of security o#11;ered by the GSM air interface protocol 1 . All known attacks concerned with the level of security o#11;ered by the GSM air interface protocol. In order to assess

  4. Frequency Assignment in GSM Networks: Models, Heuristics, and Lower Bounds

    E-print Network

    Grötschel, Martin

    Frequency Assignment in GSM Networks: Models, Heuristics, and Lower Bounds vorgelegt von Diplom possible extent when assigning the available frequencies to the base stations of a GSM cellular network). In fact, several of these methods are successfully applied by the German GSM network operator E

  5. Laser Communication Demonstration System (LCDS) and future mobile satellite services

    NASA Technical Reports Server (NTRS)

    Chen, Chien-Chung; Wilhelm, Michael D.; Lesh, James R.

    1995-01-01

    The Laser Communications Demonstration System (LCDS) is a proposed in-orbit demonstration of high data rate laser communications technology conceived jointly by NASA and U.S. industry. The program objectives are to stimulate industry development and to demonstrate the readiness of high data rate optical communications in Earth orbit. For future global satellite communication systems using intersatellite links, laser communications technology can offer reduced mass and power requirements and higher channel bandwidths without regulatory constraints. As currently envisioned, LCDS will consist of one or two orbiting laser communications terminals capable of demonstrating high data rate (greater than 750Mbps) transmission in a dynamic space environment. Two study teams led by Motorola and Ball Aerospace are currently in the process of conducting a Phase A/B mission definition study of LCDS under contracts with JPL/NASA. The studies consist of future application survey, concept and requirements definition, and a point design of the laser communications flight demonstration. It is planned that a single demonstration system will be developed based on the study results. The Phase A/B study is expected to be completed by the coming June, and the current results of the study are presented in this paper.

  6. Ad-Hoc Communication and Localization System for Mobile Robots

    NASA Astrophysics Data System (ADS)

    Neuwinger, Bernd; Witkowski, Ulf; Rückert, Ulrich

    Robots exploring unknown territory cannot rely on fixed infrastructure for communication and localization purposes. Therefore an ad-hoc communication and localization system is required to provide such facilities. In this paper a solution for a radio based localization system is presented using a 2.4 GHz wireless radio transceiver based on Chirp Spread Spectrum (CSS) modulation, which allows distance measurements by evaluating the signal propagation delay. Using odometry data as additional information source a communication and positioning system is developed fulfilling ad-hoc demands.

  7. Cross Platform Solution of Communication and Voice\\/Graphical User Interface for Mobile Devices in Vehicles

    Microsoft Academic Search

    Géza Németh; Géza Kiss; Bálint Tóth

    \\u000a Two long-term goals of our study has been to develop a standardized communication interface between the mobile device and\\u000a other onboard systems and to create a parametrical, scaleable user interface, both with voice and graphical user input\\/output.\\u000a This chapter describes the main requirements, principles, and aspects of a voice\\/graphical user interface and of a Bluetooth\\u000a based communication interface. Requirements and

  8. Mobile phones and elderly people: a noisy communication.

    PubMed

    Stamato, Cláudia; Moraes, Anamaria de

    2012-01-01

    Knowing the users is capital for building user-friendly digital interfaces. One way to think about the users is considering their familiarity with this technology. This article presents the results of twelve interviews with elderly people residing in the so-called South Zone of Rio de Janeiro (Brazil) who have used mobile phones over at least one year. It is part of the Doctor's Thesis "Mobile phones for elderly people - usability for social integration" ("Celulares para idosos - usabilidade a serviço da integraçăo social"), which is targeted at ascertaining if the current mobile phones are user-friendly for elderly people. Through the technique of Guided Interviews, we found usage time, criteria for choice of phones, reasons for changes, preferences, and manners of use. Preliminarily, we have noticed differences in the behavior of the participating users and performed a qualitative analysis according to groups of age and gender. PMID:22316743

  9. Satellite-aided land mobile communications system implementation considerations

    NASA Technical Reports Server (NTRS)

    Leroy, B. E.

    1982-01-01

    It was proposed that a satellite-based land mobile radio system could effectively extend the terrestrial cellular mobile system into rural and remote areas. The market, technical and economic feasibility for such a system is studied. Some of the aspects of implementing an operational mobile-satellite system are discussed. In particular, two key factors in implementation are examined: (1) bandwidth requirements; and (2) frequency sharing. Bandwidth requirements are derived based on the satellite antenna requirements, modulation characteristics and numbers of subscribers. Design trade-offs for the satellite system and potential implementation scenarios are identified. Frequency sharing is examined from a power flux density and modulation viewpoint. Previously announced in STAR as N82-25290

  10. IEEE Communications Magazine July 2002108 Standardization of Mobile Phone

    E-print Network

    Han, Richard Y.

    answering point (PSAP) attendants of wireless communications networks must be able to know a 911 caller to an appropriate PSAP and related emergency assistance attendants. In 1999 the FCC decided to tighten the Phase II

  11. Autonomous interactive intermediaries : social intelligence for mobile communication agents

    E-print Network

    Marti, Stefan Johannes Walter, 1965-

    2005-01-01

    Today's cellphones are passive communication portals. They are neither aware of our conversational settings, nor of the relationship between caller and callee, and often interrupt us at inappropriate times. This thesis is ...

  12. Overview of NASA Glenn Aero/Mobile Communications Demonstrations

    NASA Technical Reports Server (NTRS)

    Brooks, David; Hoder, Doug; Wilkins, Ryan

    2004-01-01

    The Glenn Research Center at Lewis Field (GRC) has been involved with several other NASA field centers on various networking and RF communications demonstrations and experiments since 1998. These collaborative experiments investigated communications technologies new to aviation, such as wideband Ku satcom, L-band narrowband satcom, and IP (Internet Protocol), using commercial off-the-shelf (COTS) components These technologies can be used to distribute weather and hazard data, air traffic management and airline fleet management information, and passenger cabin Internet service.

  13. Overview of NASA Glenn Aero/Mobile Communication Demonstrations

    NASA Technical Reports Server (NTRS)

    Brooks, David; Hoder, Doug; Wilkins, Ryan

    2004-01-01

    The Glenn Research Center at Lewis Field (GRC) has been involved with several other NASA field centers on various networking and RF communications demonstrations and experiments since 1998. These collaborative experiments investigated communications technologies new to aviation, such as wideband Ku satcom, L-band narrowband satcom, and IP (Internet Protocol), using commercial off-the-shelf (COTS) components These technologies can be used to distribute weather and hazard data, air traffic management and airline fleet management information, and passenger cabin Internet service.

  14. Rayleigh fading channels in mobile digital communication systems .I. Characterization

    Microsoft Academic Search

    Bernard Sklar

    1997-01-01

    When the mechanisms of fading channels were first modeled in the 1950s and 1960s, the ideas were primarily applied to over-the-horizon communications covering a wide range of frequency bands. The 3-30 MHz high-frequency (HF) band is used for ionospheric communications, and the 300 MHz-3 GHz ultra-high-frequency (UHF) and 3-30 GHz super-high-frequency (SHF) bands are used for tropospheric scatter. Although the

  15. Advanced mobile satellite communications system using Ka and MM-wave bands in Japan's R and D satellite project

    NASA Technical Reports Server (NTRS)

    Isobe, Shunkichi; Ohmori, Shingo; Hamamoto, Naokazu; Yamamoto, Minoru

    1991-01-01

    Communications Research Laboratory (CRL) studied an advanced mobile satellite communications system using Ka and millimeter-wave bands in the R&D Satellite project. The project started in 1990 and the satellite will be launched in 1997. On-board multi-beam interconnecting is one of basic functions to realize one-hop connection among Very Small Aperture Terminals (VSATs), mobile, and hand-held terminals in future mobile satellite communications system. An Intermediate Frequency (IF) filter bank and regenerative transponder are suitable for this function. The transponder configuration of an advanced mobile communications mission of the R&D Satellite for experiment is shown. High power transmitters of Ka and millimeter-wave bands, a 3x3 IF filter band and Single Channel Per Carrier/Time Division Multiplexing (SCPC/TDM) regenerative MODEMS, which will be boarded on the R&D Satellite, are being developed for the purpose of studying the feasibility of advanced mobile communications system.

  16. A systems approach to the commercialization of space communications technology - The NASA\\/JPL Mobile Satellite Program

    Microsoft Academic Search

    William J. Weber III; Valerie W. Gray; Byron Jackson; Laura C. Steele

    1991-01-01

    This paper discusss the systems approach taken by NASA and the Jet Propulsion Laboratory in the commercialization of land-mobile satellite services (LMSS) in the United States. As the lead center for NASA's Mobile Satellite Program, JPL was involved in identifying and addressing many of the key barriers to commercialization of mobile satellite communications, including technical, economic, regulatory and institutional risks,

  17. Near-field communication-based secure mobile payment service

    Microsoft Academic Search

    Kiran S. Kadambi; Jun Li; Alan H. Karp

    2009-01-01

    The loss of customer account information makes headlines all too often. The Payment Card Industry (PCI) Data Security Standard (DSS) has generated resistance from merchants because of its cost and complexity. Unfortunately, innovating in the Point of Sale (PoS) space is hard because the protocols have been standardized, tightly constraining new ideas. Using mobile phones as payment devices opens up

  18. Acculturation and Communicative Mobility Among Former Soviet Nationalities.

    ERIC Educational Resources Information Center

    Haarmann, Harald; Holman, Eugene

    1997-01-01

    Discusses the strategies that the former Soviet states are evolving to balance the interests of dominant ethnic groups with those of linguistic minorities while constructing a national identity, highlighting language policy in action and focusing on acculturation processes and geographic mobility among groups. A case study of Estonia is also…

  19. Department of Mobile Communications 2229, route des Crtes

    E-print Network

    Gesbert, David

    . Named Media Independent Handover Services, this standard enables in addition the mobility to and from on the media dependent mapping of the IEEE 802.21 to LTE. Index Terms Heterogeneous networks, Handover, MIH, IEEE 802.21, LTE, EPS. #12;#12;Contents 1 Introduction

  20. Channel Modeling and Simulation in Satellite Mobile Communication Systems

    Microsoft Academic Search

    Branka Vucetic; Jun Du

    1992-01-01

    An analog model describing signal amplitude and phase variations on shadowed satellite mobile channels is proposed. A linear combination of log-normal, Rayleigh, and Rice models is used to describe signal variations over an area with constant environment attributes while an M-state Markov chain is applied to represent environment parameter variations. Channel parameters are evaluated from the experimental data and utilized

  1. Channel Simulation to Facilitate Mobile-Satellite Communications Research

    Microsoft Academic Search

    Faramaz Davarian

    1987-01-01

    In designing a mobile satellite network, engineers and technologists are faced with wide-ranging issues for which there is no prior database. System engineers must address such issues as adequate margin to combat multipath fading, the level of adjacent channel protection required to allow transmission in narrow-band channels, the cochannel protection required to allow for frequency reuse in a multiplebeam system,

  2. Mobility-Tolerant Reliable Wireless LAN Multicast Communication

    Microsoft Academic Search

    V. Shankar; S. K. S. Gupta

    Reliable single-hop wireless multicast is needed for vario us applications such as multicast file transfer in a smart classroom. Mobility and wireless channel characteristics such as high bit error rate (BER) and the hidden terminal problem make providing reliability a challenging task. Further, due to the broadcast nature of the wireless medium, feedback packets such as acknowledgements and control packets

  3. Study on Wireless Behavior of Mobile Communications using

    E-print Network

    Yu, Chansu

    a higher loss of data rate due to numerous interferences and they have lower transmission rates. Background be simply described as the ability to use technology untethered. Two main aspects play a big role in mobile.11 protocol in the late 1990's played a big role in connecting these small handheld devices to the information

  4. Nomadic Pict: Correct Communication Infrastructure for Mobile Computation

    E-print Network

    Sewell, Peter

    flexibili* *ty, a wide-area programming language of the high level into the low level; we builtsNomadichPict,ould provide a low-* *level abstraction that makes distribu- a distributed programming language and verificationaoflin-gorithm. The languages c* *ited above have particular algo- frastructure for mobile computation

  5. Collaborating with Your Clients Using Social Media & Mobile Communications

    ERIC Educational Resources Information Center

    Typhina, Eli; Bardon, Robert E.; Gharis, Laurie W.

    2015-01-01

    Many Extension educators are still learning how to effectively integrate social media into their programs. By using the right social media platforms and mobile applications to create engaged, online communities, Extension educators can collaborate with clients to produce and to share information expanding and enhancing their social media and…

  6. Edgar Nett Mobile Computer Communication SS'14 1 General Overview

    E-print Network

    Access Control Telecommunication Systems Satellite Systems Broadcast Systems Wireless LAN Mobile Network.g. historic buildings, firewalls) q more robust against disasters like, e.g., earthquakes, fire - or users aspect) l difficult to predict (real-time aspect) q Transmission errors l tremendously higher loss rates

  7. Advanced mobile satellite communications system using Ka and MM-wave bands in Japan's R and D satellite project

    Microsoft Academic Search

    Shunkichi Isobe; Shingo Ohmori; Naokazu Hamamoto; Minoru Yamamoto

    1991-01-01

    Communications Research Laboratory (CRL) studied an advanced mobile satellite communications system using Ka and millimeter-wave bands in the R&D Satellite project. The project started in 1990 and the satellite will be launched in 1997. On-board multi-beam interconnecting is one of basic functions to realize one-hop connection among Very Small Aperture Terminals (VSATs), mobile, and hand-held terminals in future mobile satellite

  8. Effect of chronic exposure to a GSM-like signal (mobile phone) on survival of female Sprague-Dawley rats: modulatory effects by month of birth and possibly stage of the solar cycle.

    PubMed

    Bartsch, Hella; Küpper, Heinz; Scheurlen, Ulf; Deerberg, Fritz; Seebald, Eckard; Dietz, Klaus; Mecke, Dieter; Probst, Hansgeorg; Stehle, Thilo; Bartsch, Christian

    2010-01-01

    During 1997-2008 two long-term (I and II) and two life-long (III and IV) experiments were performed analyzing the effect of chronic exposure to a low-intensity GSM-like signal (900 MHz pulsed with 217 Hz, 100 µW/cm˛ average power flux density, 38-80 mW/kg mean specific absorption rate for whole body) on health and survival of unrestrained female Sprague-Dawley rats kept under identical conditions. Radiofrequency (RF)-exposure was started at 52-70 days of age and continued for 24 (I), 17 (II) and up to 36 and 37 months, respectively (III/IV). In the first two experiments (1997-2000) 12 exposed and 12 sham-exposed animals each were observed until they were maximally 770 or 580 days old. In experiment I no adverse health effects of chronic RF-exposure were detectable, neither by macroscopic nor detailed microscopic pathological examinations. Also in experiment II no apparent macroscopic pathological changes due to treatment were apparent. Median survival time could not be estimated since in none of the groups more than 50% of the animals had died. In the course of two complete survival experiments (2002-2005; 2005-2008) 30 RF- and 30 sham-exposed animals each were followed up until their natural end or when they became moribund and had to be euthanized. A synoptical data analysis was performed. Survival data of all four groups could be fitted well by the Weibull distribution. According to this analysis median survival was significantly shortened under RF-exposure in both experiments by 9.06% (95% CI 2.7 to 15.0%) (p=0.0064); i.e by 72 days in experiment III and 77 days in experiment IV as compared to the corresponding sham-treated animals (III: 799 days; IV: 852 days). Both groups of animals of experiment III showed reduced median survival times by 6.25% (95% CI -0.3 to 12.4%) (p=0.0604) compared to the corresponding groups of experiment IV (53 days: sham-exposed animals, 48 days: RF-exposed animals) which may be due to the fact that animals of experiment III were born in October and animals of experiment IV in May indicating that the month of birth affects life span. From the results of the last two experiments it has to be concluded that chronic exposure to a low-intensity GSM-like signal may exert negative health effects and shorten survival if treatment is applied sufficiently long and the observational period covers the full life span of the animals concerned. The current data show that survival of rats kept under controlled laboratory conditions varies within certain limits depending on the month of birth. In view of our previous observations regarding an inhibitory or no effect of RF-exposure on DMBA-induced mammary cancer during the 1997-2000 period, an additional modulatory influence on a year-to-year basis should be considered which might be related to changing solar activity during the the 11-years' sunspot cycle. These potentially complex influences of the natural environment modulating the effects of anthropogenic RF-signals on health and survival require a systematic continuation of such experiments throughout solar cycle 24 which started in 2009. PMID:20802457

  9. Characteristics of large deployable mesh reflector antennas for future mobile communications satellites

    Microsoft Academic Search

    Takashi Ebisui; Akio Iso; Teruaki Orikasa; Toshio Sugimoto; Shin-Ichi Sato

    1992-01-01

    A large deployable antenna is essential for effective mobile communication satellites. This paper describes the key technologies needed for such an antenna, the development plan, and the characteristics of various scale models. The electrical scale models of the mesh reflector antenna and the mechanical models of the deployable reflector have been constructed to aid in antenna design. The ultimate goal

  10. How Can Mobile SMS Communication Support and Enhance a First Year Undergraduate Learning Environment?

    ERIC Educational Resources Information Center

    Jones, Geraldine; Edwards, Gabriele; Reid, Alan

    2009-01-01

    In this paper we discuss a case study investigating how the academic and personal development of first year students on an undergraduate sports education degree can be supported and enhanced with mobile SMS (Short Message Service) communication. SMS-based technologies were introduced in response to students' particular needs (in transition to…

  11. SHF Cassegrain antenna with electronic beam squint tracking for high data rate mobile satellite communication systems

    Microsoft Academic Search

    B. Rama Rao; L. P. Callahan; R. J. Davis

    1994-01-01

    The design of pointing and tracking systems for vehicular antennas required for a high data rate mobile military satellite communication system is a daunting task because of its demanding requirements. Not only does the antenna have to be satellite pointed accurately towards the satellite as the vehicle moves rapidly and changes orientation, but it must also do so under scintillations

  12. Communication Research, the Rockefeller Foundation, and Mobilization for the War on Words, 1938-1944.

    ERIC Educational Resources Information Center

    Gary, Brett

    1996-01-01

    Argues that Rockefeller Foundation served as an unofficial arm of the state from 1938 to 1944 by mobilizing social-scientific expertise to fight fascism when the Roosevelt Administration was politically unable to do so. Notes that Rockefeller Foundation officer John Marshall's role in the history of American mass communication research and the…

  13. Transmission bandwidth improvement by directive antenna in urban mobile radio communication

    Microsoft Academic Search

    Tsutomu Takeuchi; Fumio Ikegami; Susumu Yoshida

    1986-01-01

    The transmission bandwidth in urban areas determines the maximum transmission rate of digital mobile communication. A directive antenna can have an effect of broadening the transmission bandwidth by itself. The transmission bandwidth improvement of proposed antenna pattern diversity reception (APDR) is estimated by computer simulation based on the measured fading data received by directive antennas in urban areas, with two

  14. Intercarrier interference self-cancellation scheme for OFDM mobile communication systems

    Microsoft Academic Search

    Yuping Zhao; Sven-Gustav Häggman

    2001-01-01

    For orthogonal frequency-division multiplexing (OFDM) communication systems, the frequency offsets in mobile radio channels distort the orthogonality between subcarriers resulting in intercarrier interference (ICI). This paper studies an efficient ICI cancellation method termed ICI self-cancellation scheme. The scheme works in two very simple steps. At the transmitter side, one data symbol is modulated onto a group of adjacent subcarriers with

  15. A DUAL-POLARIZED WIDE-BAND PATCH ANTENNA FOR INDOOR MOBILE COMMUNICATION APPLICA- TIONS

    Microsoft Academic Search

    M. Secmen; A. Hizal

    This paper proposes the conflguration of a dual- polarized wide-band patch antenna system suitable for indoor mobile communication applications. This conflguration consists of two patch antennas, which have difierent feed structures from classical patch antenna conflguration. These antennas, which are separated by a thin absorber to have a good isolation, are fed independently to obtain dual polarization. The antenna structure

  16. Edgar Nett Mobile Computer Communication SS'14 13 Access methods SDMA/FDMA/TDMA

    E-print Network

    Communication SS'14 16 Aloha (pure/slotted) - dynamic TDMA with (no/little) control sender A sender B sender C collision t Aloha sender A sender B sender C collision t Slotted Aloha #12;Edgar Nett Mobile Computer load) only 18% (Aloha), 36% (Slotted Aloha) (assuming Poisson distribution for packet arrival

  17. Development of superconductive microwave filters for mobile communications and filter banks

    Microsoft Academic Search

    B. Marcilhac; Y. Lemaitre; D. Mansart; J. C. Mage

    1999-01-01

    The development of superconductive microwave filters connected to the use of cooled electronics is now in the critical phase of system integration. All the different steps of filter development, design and fabrication must be controlled, reproducible and technically realisable by conventional microelectronics tools. We developed filters for mobile communications and filter banks with the goal of optimising these aspects. Lanthanum

  18. Dynamic 3G network selection for increasing the competition in the mobile communications market

    Microsoft Academic Search

    Gwenael Le Bodic; Demessie Girma; J. Irvine; J. Dunlop

    2000-01-01

    This paper proposes a market-based framework in which service providers, network operators and users are able to trade communications services. For this purpose, a middleware has been specified in which software agents can supply or purchase QoS contracts. Benefits from the proposal are increased competition in the provision of mobile services, an integrated framework for the management of services and

  19. WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2009; 9:705717

    E-print Network

    Jiang, Hai

    WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2009; 9:705­717 Published-tolerable localization in wireless sensor networks with inaccurately positioned anchor nodes Rongfei Fan1 , Hai Jiang1 Summary Localization is essential for wireless sensor networks (WSNs). It is to determine the positions

  20. Telephone traffic in mobile radio communication system using dynamic frequency assignments

    Microsoft Academic Search

    M. Sengoku

    1980-01-01

    Traffic characteristics of a mobile radio communication system using a dynamic channel assignment scheme which has all channels available at all base stations are derived. In the system with one channel, the traffic characteristics in each zone are exactly obtained. For a multichannel operation, some approximation methods are proposed and some simple examples are also presented.

  1. The land mobile satellite communication channel-recording, statistics, and channel model

    Microsoft Academic Search

    Erich Lutz; Daniel Cygan; Michael Dippold; Frank Dolainsky; Wolfgang Papke

    1991-01-01

    The communication channel between the MARECS satellite at 26°W and a cruising van was measured and recorded in European areas exhibiting satellite elevations from 13 to 43°. Different environments and mobile antennas were tested. The results of an extensive statistical evaluation include spectra of the fading amplitude; probability density, and distribution of the received signal power; and the percentage of

  2. Low cost electronically steered antenna and receiver system for mobile satellite communications

    Microsoft Academic Search

    J. I. Alonso; J. M. Blas; L. E. Garcia; J. Ramos; J. de Pablos; J. Grajal; G. G. Gentili; J. Gismero; F. Perez

    1996-01-01

    The design, construction, and basic characteristics of an electronically steered, adaptive phased array antenna for land mobile satellite communications are described here. The antenna system includes an array of six microstrip stacked patch antennas, each one connected to an RF channel, which include a monolithic microwave\\/millimeter wave integrated circuit (MMIC) low noise amplifier and a commercial silicon monolithic I-Q modulator.

  3. WILEY WIRELESS COMMUNICATIONS AND MOBILE COMPUTING 1 DSP Implementation of a Bit Loading

    E-print Network

    Kansas, University of

    WILEY WIRELESS COMMUNICATIONS AND MOBILE COMPUTING 1 DSP Implementation of a Bit Loading Algorithm Abstract In this paper, we present a proof-of-concept, fixed-point, DSP hardware implementation loading, DSP implementation. I. INTRODUCTION Deployed in a wide range of high data rate transmission

  4. Using proxy cache relocation to accelerate Web browsing in wireless\\/mobile communications

    Microsoft Academic Search

    Stathes Hadjiefthymiades; Lazaros F. Merakos

    2001-01-01

    Mobile computing is considered of major importance to the computing industry for the forthcoming years due to the progress in the wireless communications area. A proxy-based architecture for accelerating Web browsing in cellular customer premises networks (CPN) is presented. Proxy caches, maintained in base stations, are constantly relocated to accompany the roaming user. A cache management scheme is proposed, which

  5. Proxies + Path Prediction: Improving Web Service Provision in Wireless-Mobile Communications

    Microsoft Academic Search

    Stathes Hadjiefthymiades; Lazaros F. Merakos

    2003-01-01

    Mobile computing is considered of major importance to the computing industry for the forthcoming years due to the progress in the wireless communications area. A proxy-based architecture for accelerating Web browsing in wireless customer premises networks is presented. Proxy caches, maintained in base stations, are constantly relo- cated to accompany the roaming user. A cache management scheme is proposed, which

  6. A simple formation-tracking controller of mobile robots based on a "spanning-tree" communication

    E-print Network

    Boyer, Edmond

    show that a simple condition on the reference angular velocity (persistency of excitation) suffices robots. In [7], an adaptive leader-follower based formation control without the need of leaders' velocityA simple formation-tracking controller of mobile robots based on a "spanning-tree" communication

  7. IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 56, NO. 5, MAY 2008 743 Mobility Enhanced Smart Antenna Adaptive

    E-print Network

    Krishnamurthy, Vikram

    IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 56, NO. 5, MAY 2008 743 Mobility Enhanced Smart Antenna, and it is observed that load balancing between sectors is achieved and which greatly reduces the effect of hot spot voice/data services. Its RAKE receiver design and soft handoff greatly increase the robustness against

  8. Analysis of handoff initiation using different path loss models in mobile communication system

    Microsoft Academic Search

    Geetam S. Tomar; Shekhar Verma

    2006-01-01

    Handoff is the mechanism that transfers an ongoing call from one cell to another as a user moves through the coverage area of a cellular system. Handoff is the key operation in cellular mobile communication system, which is accomplished by the system and is unperceptible for the user. In this paper, the received signal strength from the two base stations

  9. Investigating the boundary effect of a multimedia TDMA personal mobile communication network simulation

    Microsoft Academic Search

    Aldo G. Orozco Lugo; F. A. Cruz Prez; G. Hernandez Valdez

    2001-01-01

    The boundary effect in multimedia TDMA personal mobile communication network simulation is investigated. We evaluate the performance of several channel assignment strategies (CASs) for multi-rate traffic calls in a Manhattan-like microcellular environment under two different simulation topologies. These are the wrapped around topology, which minimize the boundary effect, and the unwrapped topology, which ignore it. Both, uniform traffic and uneven

  10. MILCOM 2004-2004 IEEE MilitaryCommunications Conference ANONYMOUS HANDSHAKES IN MOBILE AD HOC NETWORKS

    E-print Network

    Latchman, Haniph A.

    MILCOM 2004- 2004 IEEE MilitaryCommunications Conference ANONYMOUS HANDSHAKES IN MOBILE AD HOC- vides the desirable sender and receiver anonymity, as well as the relationship anonymity of the sender the leakage of nodal identity informationl . This situation necessitates the development of anonymous com

  11. Securing against fraud in mobile communications : system design and development in 3G mobile networks

    E-print Network

    Mochizuki, Yujiro, 1973-

    2006-01-01

    Network security ensures the consistency, integrity, and reliability of telecommunications systems. Authorized network access prevents fraudulent communications and maintains the availability of the systems. However, limited ...

  12. Practical Context Awareness for GSM Cell Phones

    Microsoft Academic Search

    Ian Anderson; Henk L. Muller

    2006-01-01

    The ability to provide context aware behaviour on a cell phone such as whether a user is walking or driving has previously only been possible via the use of additional hardware sensors such as an accelerometer. In this paper we show that by using GSM data such as signal strength fluctuation and changes to the monitored neighbouring cells it is

  13. Design of a Mobile Agent-Based Adaptive Communication Middleware for Federations of Critical Infrastructure Simulations

    NASA Astrophysics Data System (ADS)

    Görbil, Gökçe; Gelenbe, Erol

    The simulation of critical infrastructures (CI) can involve the use of diverse domain specific simulators that run on geographically distant sites. These diverse simulators must then be coordinated to run concurrently in order to evaluate the performance of critical infrastructures which influence each other, especially in emergency or resource-critical situations. We therefore describe the design of an adaptive communication middleware that provides reliable and real-time one-to-one and group communications for federations of CI simulators over a wide-area network (WAN). The proposed middleware is composed of mobile agent-based peer-to-peer (P2P) overlays, called virtual networks (VNets), to enable resilient, adaptive and real-time communications over unreliable and dynamic physical networks (PNets). The autonomous software agents comprising the communication middleware monitor their performance and the underlying PNet, and dynamically adapt the P2P overlay and migrate over the PNet in order to optimize communications according to the requirements of the federation and the current conditions of the PNet. Reliable communications is provided via redundancy within the communication middleware and intelligent migration of agents over the PNet. The proposed middleware integrates security methods in order to protect the communication infrastructure against attacks and provide privacy and anonymity to the participants of the federation. Experiments with an initial version of the communication middleware over a real-life networking testbed show that promising improvements can be obtained for unicast and group communications via the agent migration capability of our middleware.

  14. An Admission Control-based Benefit Optimization Model for Mobile Communications: the Effect of a Decision Time Budget

    Microsoft Academic Search

    Kuo-Chung Chu; Chun-sheng Wang; Frank Yeong-Sung Lin

    2010-01-01

    In mobile communication systems, a soft handoff (SHO) technique is used to optimize the quality and capacity of communications.\\u000a However, because the handoff process incurs a high overhead there must be a tradeoff between the system capacity and the handoff\\u000a overhead. In this paper, we propose a benefit optimization model for mobile communications. The model tries to maximize the\\u000a overall

  15. A study and experiment plan for digital mobile communication via satellite

    NASA Technical Reports Server (NTRS)

    Jones, J. J.; Craighill, E. J.; Evans, R. G.; Vincze, A. D.; Tom, N. N.

    1978-01-01

    The viability of mobile communications is examined within the context of a frequency division multiple access, single channel per carrier satellite system emphasizing digital techniques to serve a large population of users. The intent is to provide the mobile users with a grade of service consistant with the requirements for remote, rural (perhaps emergency) voice communications, but which approaches toll quality speech. A traffic model is derived on which to base the determination of the required maximum number of satellite channels to provide the anticipated level of service. Various voice digitalization and digital modulation schemes are reviewed along with a general link analysis of the mobile system. Demand assignment multiple access considerations and analysis tradeoffs are presented. Finally, a completed configuration is described.

  16. Design of an anti-Rician-fading modem for mobile satellite communication systems

    NASA Technical Reports Server (NTRS)

    Kojima, Toshiharu; Ishizu, Fumio; Miyake, Makoto; Murakami, Keishi; Fujino, Tadashi

    1995-01-01

    To design a demodulator applicable to mobile satellite communication systems using differential phase shift keying modulation, we have developed key technologies including an anti-Rician-fading demodulation scheme, an initial acquisition scheme, automatic gain control (AGC), automatic frequency control (AFC), and bit timing recovery (BTR). Using these technologies, we have developed one-chip digital signal processor (DSP) modem for mobile terminal, which is compact, of light weight, and of low power consumption. Results of performance test show that the developed DSP modem achieves good performance in terms of bit error ratio in mobile satellite communication environment, i.e., Rician fading channel. It is also shown that the initial acquisition scheme acquires received signal rapidly even if the carrier-to-noise power ratio (CNR) of the received signal is considerably low.

  17. Investigations of outdoor-to-indoor mobile-to-mobile radio communication channels

    Microsoft Academic Search

    Istvan Z. Kovacs; Patrick C. F. Eggers; Kim Olesen; Leif G. Petersen

    2002-01-01

    The mobile-to-mobile radio channel was investigated in different suburban outdoor-to-indoor environments. System performance parameters in terms of un-encoded BER and outage probability have been extracted from hardware and software TETRA simulations. In several scenarios, the measured signal envelope statistics were found to be a combination of single and double Rayleigh distributions. The system performances obtained in these scenarios were in

  18. University of Plymouth,University of Plymouth, SoCCESoCCE, Mobile Communications Research Group, Mobile Communications Research Group Dr Mosa Ali AbuDr Mosa Ali Abu--RgheffRgheff --ENFERENFER JulienJulien INC2004INC2004

    E-print Network

    Abu-Rgheff, Mosa Ali

    , Mobile Communications Research Group Dr Mosa Ali AbuDr Mosa Ali Abu--RgheffRgheff -- ENFERENFER Julien Communications Research Group Dr Mosa Ali AbuDr Mosa Ali Abu--RgheffRgheff -- ENFERENFER JulienJulien INC2004INC Ali AbuDr Mosa Ali Abu--RgheffRgheff -- ENFERENFER JulienJulien INC2004INC2004 Seamless Communications

  19. Multipath link and modem design for satellite mobile communications

    NASA Astrophysics Data System (ADS)

    Gardner, F. M.

    1983-08-01

    Modems for digital L-band communication between satellites and aircraft, ships, and land vehicles are discussed. Low-rate, low-cost communications for small users is desired, so antennas are nonsteerable. Received signal-to-noise ratios are small so power conservation is critically important. Reflections from the Earth's surface have significant amplitude and cause multipath interference to the desired signal. Data rates of 100, 1200, and 4800 bps were considered. Modulation types examined include BPSK/DPSK, FSK, and GMSK. Digital implementation of the modems is proposed wherever feasible.

  20. An Integrated Routing and Scheduling Approach for Persistent Vehicle Communication in Mobile WiMAX Mesh Networks

    Microsoft Academic Search

    Rahul Amin; Kuang-Ching Wang; Parmesh Ramanathan

    2007-01-01

    The U.S. military has recently announced plans to evaluate the IEEE 802.16e Mobile WiMAX technology's potentials as a fast deployable solution for building a broadband tactical communication network. Specifically, the technology's provisions of mesh mode operation and terminal mobility allow a tactical network to be quickly deployed among mobile base stations and mobile battle units. The technology provides essential support

  1. iPads, mobile technologies, and communication applications: a survey of family wants, needs, and preferences.

    PubMed

    Meder, Allison M; Wegner, Jane R

    2015-03-01

    Families of children with communication disabilities were surveyed to explore wants and preferences relative to mobile media technology, including iPads, as a form of augmentative and alternative communication (AAC). The families surveyed reported wanting information and support from professionals, including speech language pathologists (SLPs), who are knowledgeable about AAC. These families wanted devices to meet their children's individual needs and reported that ease of use and affordability were the most influential characteristics in the purchase of mobile media devices and communication applications. SLPs who understand family decision making can utilize collaborative clinical decision making that respects families' wants and needs, while also focusing on device feature matching and family education. PMID:25685882

  2. Distributed Extremum Seeking and Cooperative Control for Mobile Communication

    E-print Network

    Ingram, Mary Ann

    ) and searches autonomously for the optimal spacings based on typical communication models. Simulation results function or its variations to achieve desired formation as well as collision avoidance [9]. In addition Shannon capacity outage probability. Hence, connectivity is maintained if the outage probability is less

  3. Joint multipath-Doppler diversity in mobile wireless communications

    Microsoft Academic Search

    Akbar M. Sayeed; Behnaam Aazhang

    1999-01-01

    We introduce a new approach for achieving diversity in spread-spectrum communications over fast-fading multipath channels. The RAKE receiver used in existing systems suffers from significant performance degradation due to the rapid channel variations encountered under fast fading. We show that the Doppler spread induced by temporal channel variations in fact provides another means for diversity that can be further exploited

  4. Communication and Sensing Trade-Offs in Decentralized Mobile Sensor Networks: A Cross-Layer Design Approach

    E-print Network

    Murray, Richard M.

    Communication and Sensing Trade-Offs in Decentralized Mobile Sensor Networks: A Cross-Layer Design the trade-offs between communication and sensing objectives, by determining the optimal sensor configurations when introducing imperfect communication. We further illustrate the performance degradation caused

  5. WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2004; 4:318 (DOI: 10.1002/wcm.160)

    E-print Network

    Lim, Sunho

    reservation; handoff 1. Introduction As cellular networks are envisioned to be a ubiquitous communicationWIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2004; 4:3­18 (DOI: 10 to the movement of users during communication sessions, one of the most important QoS factors is related

  6. Stochastic Differential Equations for Modeling, Estimation and Identification of Mobile-to-Mobile Communication Channels

    SciTech Connect

    Olama, Mohammed M [ORNL; Djouadi, Seddik M [ORNL; Charalambous, Prof. Charalambos [University of Cyprus

    2009-01-01

    Mobile-to-mobile networks are characterized by node mobility that makes the propagation environment time varying and subject to fading. As a consequence, the statistical characteristics of the received signal vary continuously, giving rise to a Doppler power spectral density (DPSD) which varies from one observation instant to the next. The current models do not capture and track the time varying characteristics. This paper is concerned with dynamical modelling of mobile-to-mobile channels, parameter estimation and identification from received signal measurements. The evolution of the propagation environment is described by stochastic differential equations. In particular, it is shown that the parameters of the models can be determined by approximating the band-limited DPSD using the Gauss-Newton method. However, since the DPSD is not available online, we propose to use a filter-based expectation maximization algorithm and Kalman filter to estimate the channel parameters and states, respectively. The scheme results in a finite dimensional filter which only uses the first and second order statistics. The algorithm is recursive allowing the inphase and quadrature components and parameters to be estimated online from received signal measurements. The algorithms are tested using experimental data collected from moving sensor nodes in indoor and outdoor environments demonstrating the method s viability.

  7. Controlled mobility of unmanned aircraft chains to optimize network capacity in realistic communication environments

    NASA Astrophysics Data System (ADS)

    Dixon, Cory

    This dissertation presents a decentralized gradient-based mobility control algorithm for the formation and maintenance of an optimal end-to-end communication chain using a team of unmanned aircraft acting as communication relays. With the use of unmanned aircraft (UA) as communication relays, a common mode of operation is to form a communication relay chain between a lead exploring node (which may be ground based or another UA) and a control station. In this type of operation the lead node is typically deployed to explore (sense) a remote region of interest that is beyond direct radio frequency (RF) communication range, or out of line-of-sight, to the control station. To provide non-line-of-sight service, and extend the communication range of the lead node, unmanned aircraft acting as communication relays are deployed in a convoy fashion behind the lead vehicle to form a cascaded relay chain. The focus of this work is the use of the mobility of a fixed number of relay aircraft to maximize the capacity of a directed communication chain from a source node to a destination node. Local objective functions are presented that use the signal-to-noise-and-interference ratio (SNIR) of neighbor communication links as inputs to maximize the end-to-end capacity of packet-based and repeater-type network chains. An adaptive gradient-based SNIR controller using the local objective function can show significant improvement in the capacity of the communication chain that is not possible with range-based controllers, or static deployment strategies, in RF environments containing unknown localized noise sources and terrain effects. Since the SNIR field is unknown, an online estimate of the SNIR field gradient is formed using methods of Stochastic Approximation from the orbital motion of the aircraft tracking a control point. Flight demonstrations using the Networked Unmanned Aircraft System Command, Control and Communications testbed were conducted to validate the controller presented herein. Results from flight experiments show that mobility of unmanned aircraft, following locally estimated SNIR gradients, can be used to form a locally optimized communication chain by driving the aircraft to locations that improve the end-to-end capacity of the chain over that of a range-based controller or a static deployment algorithm.

  8. An adaptive array antenna for mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Milne, Robert

    1990-01-01

    The design of an adaptive array antenna for land vehicle operation and its performance in an operational satellite system is described. Linear and circularly polarized antenna designs are presented. The acquisition and tracking operation of a satellite is described and the effect on the communications signal is discussed. A number of system requirements are examined that have a major impact on the antenna design. The results of environmental, power handling, and RFI testing are presented and potential problems are identified.

  9. Mobile Telephony: Realising the Dream of Ideal Communication?

    Microsoft Academic Search

    Imar de Vries

    2005-01-01

    Every existing communication technology was once new and full of promise. Upon their\\u000aintroduction, numerous producers and consumers were euphoric about the potential for immediate\\u000aapplication and had fantastic visions of future use. Most of these expectations never really came to fruition, almost every medium has developed in a\\u000adifferent way from what was foreseen, and no medium so far

  10. Communication: Charge, diffusion, and mobility of proteins through nanopores

    PubMed Central

    Muthukumar, M.

    2014-01-01

    Implementation of Einstein's law connecting charge, diffusion coefficient, and mobility to interpret experimental data on proteins from single molecule electrophoresis through nanopores faces serious difficulties. The protein charge and diffusion coefficient, inferred with the Einstein law, can be orders of magnitude smaller than their bare values depending on the electrolyte concentration, pore diameter, chemical nature of the pore wall, and the externally applied voltage. The main contributors to the discrepancies are the coupled dynamics of the protein and its counterion cloud, confinement effects inside the pore, and the protein-pore-surface interaction. We have addressed these ingredients by harking on classical theories of electrophoresis of macroions and hydrodynamics inside pores, and deriving new results for pore-protein interactions. Putting together various components, we present approximate analytical formulas for the effective charge, diffusion coefficient, and mobility of a protein in the context of single molecule electrophoresis experiments. For the omnipresent pore-protein interactions, nonlinear dependence of the velocity of protein on voltage sets in readily and analytical formulas for this effect are presented. The derived formulas enable the determination of the bare charge and size of a protein from the experimentally measured apparent values. PMID:25172998

  11. An Embedded GIS Integrating GSM and GPS under VxWorks Platform

    Microsoft Academic Search

    Peng Yu; Lin Yuye

    2010-01-01

    An embedded GIS under VxWorks operating system platform is designed and implemented. This EGIS integrates GPS position function and GSM communication function. In this paper, the key problems of designing VxWorks-based EGIS, such as data storage and data index and so on, are resolved, the main function and the design of the kernel of EGIS is given. Especially, in order

  12. The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'07) IMPLEMENTING BACKSCATTER RADIO FOR WIRELESS SENSOR NETWORKS

    E-print Network

    The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications Electric Research Laboratories, Cambridge USA Aggelos Bletsas RadioCommunications Lab (RCL) Aristotle backscatter is commonly used in RFID (Radio Frequency IDentification) systems. Radio backscatter communication

  13. Communication networks for autonomous mobile robot computer architectures and distributed real-time computing

    NASA Astrophysics Data System (ADS)

    Aras, Caglan Mehmet

    1993-12-01

    Communication networks play an increasingly important role in many areas of computing. This dissertation introduces an interprocessor communication network for mobile robot computer architectures and real-time communication networks for distributed real-time computing. In both cases, the objective of the research is to provide communication with very low delay. Mobile robot tasks such as collision avoidance and dynamic navigation change over time and exhibit a high degree of cooperation. The segmented bus is a reconfigurable interconnection network for intelligent mobile robot applications. The segmented bus employs a preemptive circuit-switched message transfer technique for low delay. For mobile robot applications, analysis suggests that message delays are lower on the segmented bus as compared to alternatives such as the multiple bus. Interactive real-time message streams are used in continuous media distributed sensing and command/control applications. These streams require low end-to-end delay bounds and zero-loss. This dissertation offers solutions to message-stream admission and low latency message transfers for interactive real-time message streams on communication networks. The proposed adaptive stream admission procedure is shown to admit more streams to a network than previous approaches. The proposed preemphasis cut-through data transfer mechanism reduces the minimum achievable end-to-end delay bound of a packet-switched network to values approaching circuit-switched techniques. To obtain low latencies on integrated broadband networks, the asynchronous transfer mode (ATM) must support bound-delay, zero-loss data transfers. A message-level delay control mechanism based on preemptive cut-through is presented. Hardware and software to implement message-level delay control are described results show a significant reduction in computation requirements when message-level delay control is used on ATM switch processors.

  14. Electronic data capture platform for clinical research based on mobile phones and near field communication technology.

    PubMed

    Morak, Jürgen; Schwetz, Verena; Hayn, Dieter; Fruhwald, Friedrich; Schreier, Gunter

    2008-01-01

    Electronic data capture systems support data acquisition for clinical research and enable the evaluation of new investigational medical devices. In case of evaluating a device the most challenging part is the user interface i.e. the solution how to acquire the data within a clinical setting and to synchronize them with a web-based data centre. The aim of this paper is to describe the development of an electronic data capture system with a mobile data input solution based on mobile phones and Near Field Communication technology. This system was evaluated within a real clinical setting and demonstrated high usability, security and reliability. PMID:19163922

  15. Performance analysis of replication ALOHA for fading mobile communications channels

    NASA Technical Reports Server (NTRS)

    Yan, Tsun-Yee; Clare, Loren P.

    1986-01-01

    This paper describes an ALOHA random access protocol for fading communications channels. A two-state Markov model is used for the channel error process to account for the channel fading memory. The ALOHA protocol is modified to send multiple contiguous copies of a message at each transmission attempt. Both pure and slotted ALOHA channels are considered. The analysis is applicable to fading environments where the channel memory is short compared to the propagation delay. It is shown that smaller delay may be achieved using replications and, in noisy conditions, can also improve throughput.

  16. [Perspectives of mobile communication in the management of diabetics].

    PubMed

    Mlekusch, Wolfgang

    2011-07-01

    Sufficient control of blood glucose levels has been demonstrated to be associated with improved long-term outcome in patients with diabetes. Recent advances in interface technology allow transfer of measurement data to mobile devices, which enables control, multiple access, and storage of these data and virtually links patients and care-giving physicians. The possibility of alerting predefined addressee in case of measurements below or above certain limits offers some sort of security that cannot be obtained by simply penning a single value to a scratchpad. Therefore, treating physicians are able to follow the therapeutic course in an easy and finally time-independent manner. Furthermore, physical contact is not necessary, which may be favorable especially for elderly, sometimes immobile patients. PMID:21858635

  17. An advanced conceptual design study for a mobile satellite communications system

    NASA Astrophysics Data System (ADS)

    Salmasi, A. B.

    It is pointed out that a vast portion of the land mass, and a significant portion of the U.S. population in rural and remote areas, are deprived of most of the advanced telecommunication services offered in metropolitan areas. For the last decade, investigations have been conducted regarding the feasibility to provide telecommunication services throughtout the thinly populated areas with the aid of a geostationary satellite. The considered communication services are related to mobile and thin-route radiotelephony, wideband and narrowband data transmissions, and position location services. The mobile satellite (MSAT) communications system studied could provide a truly national and ubiquitous service. Attention is given to satellite antenna design, an MSAT link design analysis, and analysis results.

  18. Trellis coding with Continuous Phase Modulation (CPM) for satellite-based land-mobile communications

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This volume of the final report summarizes the results of our studies on the satellite-based mobile communications project. It includes: a detailed analysis, design, and simulations of trellis coded, full/partial response CPM signals with/without interleaving over various Rician fading channels; analysis and simulation of computational cutoff rates for coherent, noncoherent, and differential detection of CPM signals; optimization of the complete transmission system; analysis and simulation of power spectrum of the CPM signals; design and development of a class of Doppler frequency shift estimators; design and development of a symbol timing recovery circuit; and breadboard implementation of the transmission system. Studies prove the suitability of the CPM system for mobile communications.

  19. Research on the Radiation Field of Mono-radiation Wide-Band Leaky Coaxial Cable Using for 3G Mobile Communication

    Microsoft Academic Search

    Guojian Yang; Zhuo Wang

    \\u000a To solve the problem of shortage of low frequencies along with the development of mobile communication, the research on the\\u000a leaky communication system using for the mobile communication in blind and semi-blind zone was towards to high frequency and\\u000a wide frequency area. Combining with the 3G and 2G mobile communication frequency band, the method of expanding the frequency\\u000a range of

  20. Low-Density Parity-Check Code Design for GSM

    Microsoft Academic Search

    Andre M. Mc Donald; Jan C. Olivier

    We present a technique for designing low-density parity-check (LDPC) code matrices for the MCS-1 to MCS-4 coding schemes of GSM. We demonstrate that these codes have significant performance gains over randomly constructed LDPC codes in the GSM setup. The new codes also show significant gains in performance over the conventional MCS-1 to MCS-4 GSM coding schemes when compared in terms

  1. Frequency Coordination Between UMTS and GSM Systems at 900 MHZ

    Microsoft Academic Search

    Vieri Vanghi; Mustafa Saglam; Jiang Jindi

    2007-01-01

    UTRA-FDD requirements for operation in the 900 MHz band have been recently standardized in 3 GPP paving the way for refarming of GSM spectrum to UMTS. UMTS900 networks will have to co-exist with GSM900 networks for some time. 3GPP (2005) has studied co-existence issues and has concluded that GSM900 and UMTS900 can co-exist in both coordinated and un-coordinated deployments in

  2. Performance of equalizers employing a re-training RLS algorithm for digital mobile radio communications

    Microsoft Academic Search

    Takashi Ueda; Hiroshi Suzuki

    1990-01-01

    To improve the transmission performance of high bit-rate digital mobile radio communications in frequency-selective fading environments, a retraining recursive least squares (RT-RLS) algorithm for a decision feedback equalizer (DFE) is proposed. Performance evaluation experiments were carried out with a real-time experimental system that includes a DFE implemented by a single-chip digital signal processor (DSP). Experiments were performed by transmitting 250

  3. Mobile communications experiments on dual-band triangular-patch array antenna using a pseudo satellite

    Microsoft Academic Search

    Toshimitsu TANAKA; J. T. S. Sumantyo; K. Kaneko; D. Ishide; M. Takahashi; K. Ito; S. Yamamoto; A. Miura

    2005-01-01

    A simple satellite-tracking array antenna for mobile satellite communications aimed at ETS-VIII applications has been discussed. The proposed antenna is constituted of triangular patches sequentially rotated by 120°. By successively turning off any one of the patches, it is shown that three beams are created in the conical-cut plane for transmission and reception. Furthermore, the gain can reach more than

  4. New space-time channel models for 2 GHz mobile communications systems with an antenna array

    Microsoft Academic Search

    Ma Ning; Li Ping'an

    2005-01-01

    Two new space-time channel models are introduced for simulating 2 GHz wireless mobile communication systems in outdoor environments. The models combine in reason the power and delay parameters in different environments provided by ITU or 3GPP and the angle parameters generated according to 3GPP\\/3GPP2 joint spatial channel modeling adhoc. The new models can be directly used in the simulations of

  5. DFT Spread Generalized Multi-Carrier Scheme for Broadband Mobile Communications

    Microsoft Academic Search

    Xiaodong Zhang; Mingqi Li; Honglin Hu; Haifeng Wang; Bin Zhou; Xiaohu You

    2006-01-01

    A DFT spread generalized multi-carrier (GMC) based frequency division multiple access (FDMA) scheme, i.e. DFT-S-GMC, is proposed for uplink transmission of wideband mobile communication systems. The scheme achieves spreading gains in the frequency-domain by discrete Fourier transform (DFT), and the frequency division multiplexing (FDM) and FDMA by inverse filter-bank transform (IFBT). By theoretical analysis and simulation results, it is shown

  6. A wide-band propagation model based on UTD for cellular mobile radio communications

    Microsoft Academic Search

    Wei Zhang

    1997-01-01

    The present wide-band propagation model based on uniform geometrical theory of diffraction (UTD) for cellular mobile radio communications includes two major contributions. First, a UTD-based narrow-band channel transfer function containing both the diffracted electric field and the reflection of diffracted electric fields is derived. Not only is it an important element of the wide-band modeling method, but it also leads

  7. Convolutionally interleaved PSK and DPSK trellis codes for shadowed, fast fading mobile satellite communication channels

    Microsoft Academic Search

    A. C. M. Lee; PETER J. McLANE

    1990-01-01

    Using a model from the literature, the performance of convolutionally interleaved phase-shift-keying (PSK) and differential phase-shift-keying (DPSK) trellis codes for digital speech transmission over shadowed mobile satellite communication channels is determined by computer simulation. First the characteristics of fading channels are examined and analyzed in terms of the probability distributions of amplitude, phase, and burst errors. A statistical method, using

  8. Dual-band circularly polarized equilateral triangular-patch array antenna for mobile satellite communications

    Microsoft Academic Search

    J. T. S. Sumantyo; K. Ito; M. Takahashi

    2005-01-01

    The Japan Aerospace Exploration Agency will launch the Engineering Test Satellite VIII (ETS-VIII) in 2006 to support the next generation of mobile satellite communications covering the area of Japan (beam coverage El=38° to 58°). In this paper, a satellite-tracking left-handed circularly polarized triangular-patch array antenna is developed for ground applications. The targeted minimum gain of the antenna is set to

  9. PSK and DPSK trellis codes for fast fading, shadowed mobile satellite communication channels

    Microsoft Academic Search

    P. J. McLane; P. H. Wittke; P. K.-M. Ho; C. Loo

    1988-01-01

    The performance of 8-PSK and 8-DPSK trellis codes is presented for a class of fast fading, land mobile satellite communication channels. The fading model is Rician but, in addition, the line-of-sight path is subjected to a fast lognormal attenuation that represents tree shadowing. The fading parameters used in this study represent the degree of shadowing and are based on measured

  10. Wideband DS-CDMA for next-generation mobile communications systems

    Microsoft Academic Search

    Fumiyuki Adachi; Mamoru Sawahashi; Hirohito Suda

    1998-01-01

    Wideband wireless access based on direct sequence code division multiple access aimed at third-generation mobile communications systems is reviewed. W-CDMA is designed to flexibly offer wideband services which cannot be provided by present cellular systems, with various data rates as high as 2 Mb\\/s. The important concept of W-CDMA is the introduction of intercell asynchronous operation and the pilot channel

  11. Effect of Mobility on Communication Performance in Overloaded One-Dimensional Cellular Networks

    Microsoft Academic Search

    Michihiro Inoue; Noriaki Yoshiura; Yoshikuni Onozato

    2005-01-01

    \\u000a In this paper, we investigate the communication performance of one-dimensional cellular networks from the viewpoint of the\\u000a mobile node’s speed with the simulation method assuming various types of speed distributions. Simulation results are measured\\u000a as blocking probabilities of both new and handoff calls and call completion probability. We can observe the phenomenon that\\u000a blocking probabilities of both new and handoff

  12. The global footprint of mobile communications: The ecological and economic perspective

    Microsoft Academic Search

    Albrecht Fehske; Gerhard Fettweis; Jens Malmodin; Gergely Biczok

    2011-01-01

    This article quantifies the global carbon footprint of mobile communication systems, and discusses its ecological and economic implications. Using up-to-date data and life cycle assessment models, we predict an increase of CO2 equivalent emissions by a factor of three until 2020 compared to 2007, rising from about 86 to 235 Mto CO2e, suggesting a steeper increase than predicted in the

  13. A description of QUALCOMM Automatic Satellite Position Reporting (QASPR(R)) for mobile communications

    NASA Technical Reports Server (NTRS)

    Ames, William G.

    1990-01-01

    Two satellite position reporting has been introduced into the OmniTRACS mobile satellite communication system. This system significantly improves position reporting reliability and accuracy while simplifying the terminal's hardware. The positioning technique uses the original OmniTRACS TDMA timing signal formats in the forward and return link directions plus an auxiliary, low power forward link signal through a second satellite to derive distance values. The distances are then converted into the mobile terminal's latitude and longitude in real time. A minor augmentation of the spread spectrum profile of the return link allowed the resolution of periodic ambiguities. The system also locates the two satellites in real time with fixed platforms in known locations using identical mobile terminal hardware. Initial accuracies of 1/4 mile have been realized uniformly throughout the USA using a satellite separation of 22 degrees and there are no dead zones, skywaves, or cycle slips as found in terrestrial systems like LORAN-C.

  14. Broadband and scalable mobile satellite communication system for future access networks

    NASA Astrophysics Data System (ADS)

    Ohata, Kohei; Kobayashi, Kiyoshi; Nakahira, Katsuya; Ueba, Masazumi

    2005-07-01

    Due to the recent market trends, NTT has begun research into next generation satellite communication systems, such as broadband and scalable mobile communication systems. One service application objective is to provide broadband Internet access for transportation systems, temporal broadband access networks and telemetries to remote areas. While these are niche markets the total amount of capacity should be significant. We set a 1-Gb/s total transmission capacity as our goal. Our key concern is the system cost, which means that the system should be unified system with diversified services and not tailored for each application. As satellites account for a large portion of the total system cost, we set the target satellite size as a small, one-ton class dry mass with a 2-kW class payload power. In addition to the payload power and weight, the mobile satellite's frequency band is extremely limited. Therefore, we need to develop innovative technologies that will reduce the weight and maximize spectrum and power efficiency. Another challenge is the need for the system to handle up to 50 dB and a wide data rate range of other applications. This paper describes the key communication system technologies; the frequency reuse strategy, multiplexing scheme, resource allocation scheme, and QoS management algorithm to ensure excellent spectrum efficiency and support a variety of services and quality requirements in the mobile environment.

  15. Ku-Band Low-Profile Rx-only and Tx-Rx antennas for Mobile Satellite Communications

    Microsoft Academic Search

    Stefano Vaccaro; F. Tiezzi; M. F. Ru?a; C. D. G. De Oro

    2010-01-01

    This paper presents two different Ku-Band Low-Profile antenna concepts for Mobile Satellite Communications. The antennas are based on low-cost hybrid mechanical-electronic steerable solutions but, while the first one allows a broadband reception of a satellite signal (Receive-only antenna concept), the second one provides transmit and receive functions for a bi-directional communication link between the satellite and the mobile user terminal

  16. 7 CFR 1493.6 - Additional required determinations for GSM-103.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Additional required determinations for GSM-103. 1493.6 Section 1493.6 ...Additional required determinations for GSM-103. Notwithstanding any other provision...part, CCC shall not guarantee under the GSM-103 program the repayment of...

  17. 7 CFR 1493.6 - Additional required determinations for GSM-103.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Additional required determinations for GSM-103. 1493.6 Section 1493.6 ...Additional required determinations for GSM-103. Notwithstanding any other provision...part, CCC shall not guarantee under the GSM-103 program the repayment of...

  18. ON THE IMPACT OF GSM ENCRYPTION AND MAN-IN-THE-MIDDLE ATTACKS ON THE SECURITY OF INTEROPERATING GSM/UMTS NETWORKS

    E-print Network

    Wetzel, Susanne

    ON THE IMPACT OF GSM ENCRYPTION AND MAN-IN-THE-MIDDLE ATTACKS ON THE SECURITY OF INTEROPERATING GSM@cs.stevens-tech.edu Abstract - GSM suffers from various security weaknesses: Just recently, Barkan, Biham and Keller presented a cipher- text-only attack on the GSM encryption algorithm AY2 which recovers the encryption key from a few

  19. Communication and Political Mobilization: Digital Media and the Organization of Anti-Iraq War Demonstrations in the U.S

    Microsoft Academic Search

    W. Lance Bennett; Christian Breunig; Terri Givens

    2008-01-01

    The speed and scale of mobilization in many contemporary protest events may reflect a transformation of movement organizations toward looser ties with members, enabling broader mobilization through the mechanism of dense individual-level political networks. This analysis explores the dynamics of this communication process in the case of U.S. protests against the Iraq war in 2003. We hypothesize that individual activists

  20. Error rate performance of noncoherent detection of duobinary coded MSK and TFM in mobile radio communication systems

    Microsoft Academic Search

    S. Elnoubi; S. C. Gupta

    1981-01-01

    Two continuous phase constant envelope modulation schemes are considered for use in digital mobile radio communication systems. These two schemes, duobinary coded minimum shift keying (MSK) and tamed frequency modulation (TFM), use partial response signaling to achieve efficient power spectrum. Therefore, they are suitable candidates for the application of digital data transmission via mobile radio where spectrum efficiency is an

  1. AN ANALYSIS OF MOBILITY MODEL IN CELLULAR COMMUNICATION SYSTEM USING GAUSSIAN PROBABILITY DENSITY FUNCTION FOR HANDOVER DIRECTION

    Microsoft Academic Search

    S. Phokeewanichkul; B. Homnan

    In this paper, the handover direction based on Gaussian probability density function (Gaussian pdf) is applied for analyzing the mathematical mobility model in cellular communication systems. Since an updated handover direction is related to the speed's range of a mobile station (MS); therefore, the Gaussian pdf should be more suitable for using as the direction pdf at cell boundary than

  2. Handoff with DSP Support: Enabling Seamless Voice Communications across Heterogeneous Telephony Systems on Dual-Mode Mobile Devices

    Microsoft Academic Search

    Hung-yun Hsieh; Chung-wei Li; Hsiao-pu Lin

    2009-01-01

    Many mobile handsets manufactured today are equipped with wireless data modules that can provide users with the alternative to access Internet telephony service for voice communications. Due to the limited coverage area of wireless data service, however, a call established through VoIP service may need to be transferred transparently to mobile telephony service, and vice versa, for maintaining voice call

  3. Design and Implementation of Remote Monitoring System Based on GSM

    Microsoft Academic Search

    Peijiang Chen; Xuehua Jiang

    2008-01-01

    Because the wireless remote monitoring system has more and more application, a remote monitoring system based on SMS of GSM is presented. Based on the total design of the system, the hardware and software of the system is designed. In this system, GSM network is a medium for transmitting the remote signal. The system includes two parts which are the

  4. Effects of mobile phone exposure on time frequency fine structure of transiently evoked otoacoustic emissions.

    PubMed

    Paglialonga, Alessia; Tognola, Gabriella; Parazzini, Marta; Lutman, Mark E; Bell, Steven L; Thuroczy, Gyorgy; Ravazzani, Paolo

    2007-10-01

    Mobile phones have become very commonly used worldwide within a short period of time. To date there is only limited knowledge about interaction between electromagnetic fields (EMFs) emitted by mobile phones and the auditory function. Moreover, there is widespread concern that there may be potential for harm. The aim of this study was to assess potential subtle changes in cochlear function by measuring the temporal and spectral fine structure of transiently evoked otoacoustic emissions (TEOAE) in normal hearing subjects after exposure to EMFs emitted by Global System for Mobile Communication (GSM) mobile phones. TEOAEs were recorded in 27 healthy young adults before and after 10 min of real or sham exposure in a double-blind design. TEOAE data were analyzed both globally (broadband analysis) and using the Wavelet Transform (analysis of the time-frequency fine structure). The broadband analysis revealed no significant effect on TEOAEs related to exposure, confirming results of previous studies; in addition, no significant change was detected in the analysis of the elementary wavelet components, suggesting that the temporal and spectral fine structure of TEOAEs is not affected by 10 min exposure to low-intensity EMFs emitted by GSM mobile phones. PMID:17902853

  5. A study of land mobile satellite communication systems in the geostationary platform area

    NASA Astrophysics Data System (ADS)

    Kohmura, M.; Otsu, Y.; Miyasaka, K.; Uda, H.

    The design concept of a land mobile communication (LMC) network for Japan, based on a multiple-beam GEO platform to be launched early in the 21st century, is discussed. The market for LMC services is assessed; the LMC frequency-reuse requirements for the major Japanese metropolitan areas are estimated; and particular attention is given to recent advances in multibeam antennas and transponders, LMC network configurations, LMC terminals, propagation and modulation coding, and the possible inclusion of hardware for mm-wave communication and direct broadcasting on the platform. The payload weight and power requirements for a dedicated LMC platform are estimated as 1100 kg and 2.5 kW; the values for the multiple-use platform are 2000 kg and 10-13 kW, respectively.

  6. Using a Communication Model to Collect Measurement Data through Mobile Devices

    PubMed Central

    Bravo, José; Villarreal, Vladimir; Hervás, Ramón; Urzaiz, Gabriel

    2012-01-01

    Wireless systems and services have undergone remarkable development since the first mobile phone system was introduced in the early 1980s. The use of sensors in an Ambient Intelligence approach is a great solution in a medical environment. We define a communication architecture to facilitate the information transfer between all connected devices. This model is based in layers to allow the collection of measurement data to be used in our framework monitoring architecture. An overlay-based solution is built between network elements in order to provide an efficient and highly functional communication platform that allows the connection of a wide variety of devices and technologies, and serves also to perform additional functions such as the possibility to perform some processing in the network that may help to improve overall performance. PMID:23012542

  7. A spread-spectrum modem using constant envelope BPSK for a mobile satellite communications terminal

    NASA Technical Reports Server (NTRS)

    Iizuka, N.; Yamashita, A.; Takenaka, S.; Morikawa, E.; Ikegami, T.

    1990-01-01

    This paper describes a 5-kilobit/s spread spectrum modem with a 1.275 mega-Hz chip rate for mobile satellite communications. We used a Viterbi decoder with a coding gain of 7.8 dB at a BER of 10(exp -5) to decrease the required receiver power. This reduces the cost of communication services. The spread spectrum technique makes the modem immune to terrestrial radio signals and keeps it from causing interference in terrestrial radio systems. A class C power amplifier reduces the modem's power consumption. To avoid nonlinear distortion caused by the amplifier, the envelope of the input signal is kept constant by adding quadrature channel signal to the BPSK signal. To simulate the worst case, we measured the modem's output spectrum using a limiting amplifier instead of the class C amplifier, and found that 99 percent of the spectral power was confined to the specified 2.55 mega-Hz bandwidth.

  8. The ELLIPSO (tm) system: Elliptical low orbits for mobile communications and other optimum system elements

    NASA Astrophysics Data System (ADS)

    Castiel, David

    1991-09-01

    On 5 Nov. 1990, Ellipsat filed with the FCC the first application to provide voice communication services via low earth orbiting (LEO) satellites. The proposed system, ELLIPSO, aims at achieving end-user costs comparable to those in the cellular industry. On 3 Jun. 1991 Ellipsat filed for the second complement of its system. Ellipsat was also the first company to propose combined position determination and mobile voice services via low-earth orbiting satellites. Ellipsat is still the only proponent of elliptical orbits for any commercial system in the United States. ELLIPSO uses a spectrum efficient combination of FDMA and CDMA techniques. Ellipsat's strategy is to tailor required capacity to user demand, reduce initial system costs and investment risks, and allow the provision of services at affordable end-user prices. ELLIPSO offers optimum features in all the components of its system, elliptical orbits, small satellites, integrated protocol and signalling system, integrated end-user electronics, novel marketing approach based on the cooperation with the tenets of mobile communications, end-user costs that are affordable, and a low risk approach as deployment is tailored to the growth of its customer base. The efficient design of the ELLIPSO constellation and system allows estimated end-user costs in the $.50 per minute range, five to six times less than any other system of comparable capability.

  9. A New mHealth Communication Framework for Use in Wearable WBANs and Mobile Technologies

    PubMed Central

    Hamida, Sana Tmar-Ben; Hamida, Elyes Ben; Ahmed, Beena

    2015-01-01

    Driven by the development of biomedical sensors and the availability of high mobile bandwidth, mobile health (mHealth) systems are now offering a wider range of new services. This revolution makes the idea of in-home health monitoring practical and provides the opportunity for assessment in “real-world” environments producing more ecologically valid data. In the field of insomnia diagnosis, for example, it is now possible to offer patients wearable sleep monitoring systems which can be used in the comfort of their homes over long periods of time. The recorded data collected from body sensors can be sent to a remote clinical back-end system for analysis and assessment. Most of the research on sleep reported in the literature mainly looks into how to automate the analysis of the sleep data and does not address the problem of the efficient encoding and secure transmissions of the collected health data. This article reviews the key enabling communication technologies and research challenges for the design of efficient mHealth systems. An end-to-end mHealth system architecture enabling the remote assessment and monitoring of patient's sleep disorders is then proposed and described as a case study. Finally, various mHealth data serialization formats and machine-to-machine (M2M) communication protocols are evaluated and compared under realistic operating conditions. PMID:25654718

  10. Structured P2P overlay of mobile brokers for realizing publish/subscribe communication in VANET.

    PubMed

    Pandey, Tulika; Garg, Deepak; Gore, Manoj Madhava

    2014-01-01

    Publish/subscribe communication paradigm provides asynchrony and decoupling, making it an elegant alternative for designing applications in distributed and dynamic environment such as vehicular ad hoc networks (VANETs). In this paradigm, the broker is the most important component that decouples other two components, namely, publisher and subscriber. Previous research efforts have either utilized the deployment of distributed brokers on stationary road side info-stations or have assigned the role of broker to any moving vehicle on ad hoc basis. In one approach, lots of preinstalled infrastructures are needed whereas, in another, the quality of service is not guaranteed due to unpredictable moving and stopping patterns of vehicles. In this paper, we present the architecture of distributed mobile brokers which are dynamically reconfigurable in the form of structured P2P overlay and act as rendezvous points for matching publications and subscriptions. We have taken city buses in urban settings to act as mobile brokers whereas other vehicles are considered to be in role of publishers and subscribers. These mobile brokers also assist in locating a vehicle for successful and timely transfer of notifications. We have performed an extensive simulation study to compare our approach with previously proposed approaches. Simulation results establish the applicability of our approach. PMID:24523629

  11. GSM & web-based flood monitoring system

    NASA Astrophysics Data System (ADS)

    Pagatpat, J. C.; Arellano, A. C.; Gerasta, O. J.

    2015-06-01

    The purpose of this project is to develop a local real-time river flood monitoring and warning system for the selected communities near MandulogRiver. This study focuses only on the detection and early warning alert system (via website and/or cell phone text messages) that alerts local subscribers of potential flood events. Furthermore, this system is interactive wherein all non-registered subscribers could inquire the actual water level of the desired area location they want to monitor. An estimated time a particular river waterway will overflow is also included in the analyses. The hardware used in the design is split into several parts namely: the water level detector, GSM module, and microcontroller development board.

  12. 76 FR 44836 - CCC Export Credit Guarantee (GSM-102) Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-27

    ...DEPARTMENT OF AGRICULTURE Commodity Credit Corporation 7 CFR Part 1493 RIN 0551-AA74 CCC Export Credit Guarantee (GSM-102) Program AGENCY: Foreign Agricultural Service and Commodity Credit Corporation, USDA. ACTION:...

  13. 76 FR 57940 - CCC Export Credit Guarantee (GSM-102) Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-19

    ...DEPARTMENT OF AGRICULTURE Commodity Credit Corporation 7 CFR Part 1493 RIN 0551-AA74 CCC Export Credit Guarantee (GSM-102) Program AGENCY: Foreign Agricultural Service and Commodity Credit Corporation, USDA. ACTION:...

  14. Single antenna interference cancellation in asynchronous GSM/GPRS networks

    E-print Network

    Chan, Chung, Ph. D. Massachusetts Institute of Technology

    2005-01-01

    In this project, we have proposed a decorrelator-based single antenna interference cancellation algorithm for the asynchronous GSM/GPRS network. The algorithm is tested according to the current SAIC/DARP performance ...

  15. SUPL support for mobile devices

    NASA Astrophysics Data System (ADS)

    Narisetty, Jayanthi; Soghoyan, Arpine; Sundaramurthy, Mohanapriya; Akopian, David

    2012-02-01

    Conventional Global Positioning System (GPS) receivers operate well in open-sky environments. But their performance degrades in urban canyons, indoors and underground due to multipath, foliage, dissipation, etc. To overcome such situations, several enhancements have been suggested such as Assisted GPS (A-GPS). Using this approach, orbital parameters including ephemeris and almanac along with reference time and coarse location information are provided to GPS receivers to assist in acquisition of weak signals. To test A-GPS enabled receivers high-end simulators are used, which are not affordable by many academic institutions. This paper presents an economical A-GPS supplement for inexpensive simulators which operates on application layer. Particularly proposed solution is integrated with National Instruments' (NI) GPS Simulation Toolkit and implemented using NI's Labview environment. This A-GPS support works for J2ME and Android platforms. The communication between the simulator and the receiver is in accordance with the Secure User Plane Location (SUPL) protocol encapsulated with Radio Resource Location Protocol (RRLP) applies to Global System for Mobile Communications (GSM) and Universal Mobile Telecommunications System (UMTS) cellular networks.

  16. Design of intelligent fire alarm system based on GSM network

    Microsoft Academic Search

    Chun-yuan Lian

    2011-01-01

    In order to solve the problem of complex cabling, misdeclaration and missing alarm of traditional fire alarm system, an intelligent fire alarm system based on GSM network is designed. MSP430F149 is adopted as main control chip, and the remote alarming and data exchanging are achieved by using GSM module TC35I. By adopting smoke detector and temperature detector and using a

  17. Performance enhancements for the GSM\\/EDGE Radio Access Network

    Microsoft Academic Search

    M. Berg; M. Eriksson; D. Hui; C. Lindheimer; S. Mazur; J. Molno; E. Kronestedt; C. Tidestav; K. Zangi

    2000-01-01

    The GSM\\/EDGE Radio Access Network (GERAN) denotes the common evolution of GSM, TDMA\\/136 and EDGE towards providing full third generation services and is currently being standardized in ETSI. In its first phase, EDGE provides high data rates for non-real-time services using high level modulation. In the second phase of the standardization, EDGE will provide real-time services over an all-IP core

  18. Mobility management in mobile IP

    Microsoft Academic Search

    Sirisha Medidi; Forouzan Golshani

    2002-01-01

    There is an emerging interest in integrating mobile wireless communication with the Internet based on the Ipv6 technology. Many issues introduced by the mobility of users arise when such an integration is attempted. This paper addresses the problem of mobility management, i.e., that of tracking the current IP addresses of mobile terminals and sustaining active IP connections as mobiles move.

  19. Measured path loss and multipath propagation characteristics in UHF and microwave frequency bands for urban mobile communications

    Microsoft Academic Search

    Yasuhiro Oda; Reiko Tsuchihashi; Kouichi Tsunekawa; Masaharu Hata

    2001-01-01

    This paper presents the frequency dependence of propagation loss and multipath propagation characteristics for urban mobile communications based on measurement results in Japanese urban areas. Path loss in reference frequencies from 457.2 MHz to 15.45 GHz increases according to the free space propagation power law in terms of frequency dependence for both macrocell and microcell environments. The standard deviation of

  20. 21st Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications A QoS Tracking Algorithm for

    E-print Network

    Valaee, Shahrokh

    21st Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications A QoS each node in order to provide QoS differ entiation gaps among AC queues. It has been shown nodes. Briefly, for QoS differentiation, many schemes such as [5, 10, 1 1] were proposed to use

  1. Edgar Nett Mobile Computer Communication SS'14 22 Using Spreading for all signals of a frequency band

    E-print Network

    Mobile Computer Communication SS'14 23 DSSS (Direct Sequence Spread Spectrum) I Product of stream'14 24 DSSS (Direct Sequence Spread Spectrum) II X user data chipping sequence modulator radio carrier to using FDM 2 2 2 2 2 frequency channel quality 1 spread spectrum spread spectrum channels #12;Edgar Nett

  2. Competition between regional standards and the success and failure of firms in the world-wide mobile communication market

    Microsoft Academic Search

    Jefrey L Funk

    1998-01-01

    This paper describes the evolution of competition in the world-wide mobile communication market. Most firms have succeeded with products (infrastructure and phones) and phone services that are based on domestic standards, while relatively few firms (Ericsson, Motorola, and Nokia) have succeeded in the development of infrastructure and phones that are based on non-domestic standards. The lack of firms which have

  3. Near-toll-quality real-time speech coding at 4.8 kbit/s for mobile satellite communications

    NASA Astrophysics Data System (ADS)

    Tzeng, F. F.

    This paper addresses the design issues of a near-toll-quality 4.8-kbit/s speech coder for real-time mobile satellite communications applications. Specifically, methods for coder performance improvement, computational complexity reduction, and memory complexity reduction are presented. Considerations for coder operation under noisy, fading channels are also discussed.

  4. The Complexity of Social Mobilization in Health Communication: Top-Down and Bottom-Up Experiences in Polio Eradication

    Microsoft Academic Search

    Rafael Obregón; Silvio Waisbord

    2010-01-01

    The Polio Eradication Initiative (PEI) has been one of the most ambitious global health efforts in recent times. Social mobilization (SM) has been a strategic component of the PEI. Yet, a close-up analysis of SM dynamics seems to be lacking in the health communication literature. We examine critical aspects of the PEI experience in an attempt to move from dominant

  5. Proc. of IEEE Wireless Communications and Networking Conference (WCNC), March 2003 Mobility Patterns in Microcellular Wireless Networks

    E-print Network

    Peha, Jon M.

    Proc. of IEEE Wireless Communications and Networking Conference (WCNC), March 2003 Mobility Patterns in Microcellular Wireless Networks Suttipong Thajchayapong and Jon M. Peha Department- cellular wireless networks, based on measurements from the 802.11-based system that blankets the Carnegie

  6. Performance Analysis of Maximal Ratio Combining and Comparison with Optimum Combining for Mobile Radio Communications with Cochannel Interference

    Microsoft Academic Search

    A. Shah; A. M. Haimovich

    2000-01-01

    The performance of maximal ratio combining for space diversity reception in digital cellular mobile radio systems is studied for communications in the presence of multiple cochannel interference (CCI) sources and is compared to optimum com- bining. The main contribution of the paper is that the analysis accounts for fading of the signal of interest (SOI) as well as the cochannel

  7. Performance of multi-level QAM with maximal ratio combining space diversity for land mobile radio communications

    Microsoft Academic Search

    S. Sampei; T. Sunaga

    1990-01-01

    A novel type of space diversity with maximal ratio combining for multilevel quadrature amplitude modulation (QAM) in land mobile communications to improve transmission performance is proposed. In order to realize maximal ratio combining space diversity for QAM, a novel type of diversity combining method using a pilot symbol insertion type fading estimator is applied. The proposed diversity combining is carried

  8. JOURNAL OF COMMUNICATIONS AND NETWORKS, ? 1 Application of Network Coding to IEEE 802.16j Mobile

    E-print Network

    Jang, Ju-Wook

    IEEE 802.16j draft standard does not allow broadcast needed for network coding. We devise a new frameJOURNAL OF COMMUNICATIONS AND NETWORKS, ? 1 Application of Network Coding to IEEE 802.16j Mobile Multi-hop Relay (MMR) Network for Throughput Enhancement Kyungjun Lee, Wonjin Sung, Ju Wook Jang

  9. 2172 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 49, NO. 12, DECEMBER 2001 Estimation of Mobile Speed and Average Received

    E-print Network

    Cox, Donald C.

    2172 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 49, NO. 12, DECEMBER 2001 Estimation of Mobile Speed and average power estimates are also used to detect the corner effect in urban cellular systems to improve handoff performance and reduce the call dropping rate. Index Terms--Speed estimation, wavelets, wireless

  10. SUBMITTED TO IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 1 Stochastic Geometric Analysis of User Mobility in

    E-print Network

    Liang, Ben

    SUBMITTED TO IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 1 Stochastic Geometric Analysis Member, IEEE Abstract--Horizontal and vertical handoffs are important ramifications of user mobility in different tiers. We derive theoretical expressions for the rates of all handoff types experienced

  11. Informing the public about information and participation strategies in the siting of mobile communication base stations: an experimental study

    Microsoft Academic Search

    Peter M. Wiedemann; Holger Schütz

    2008-01-01

    Informing the public and ensuring their participation are considered important characteristics for a successful siting of mobile communication base stations. However, there is only sparse empirical evidence for this presumption. In particular, nothing is known about whether informing people that a siting decision is based on public information and participation activities has any positive effects. The experimental study presented here

  12. 7 CFR 1488.22 - Communications.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...COMMODITIES Financing of Export Sales of Agricultural Commodities From Private Stocks Under CCC Export Credit Sales Program (GSM-5) Miscellaneous Provisions § 1488.22 Communications. (a) Unless otherwise provided, written...

  13. 7 CFR 1488.22 - Communications.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...COMMODITIES Financing of Export Sales of Agricultural Commodities From Private Stocks Under CCC Export Credit Sales Program (GSM-5) Miscellaneous Provisions § 1488.22 Communications. (a) Unless otherwise provided, written...

  14. Concepts and cost trade-offs for land vehicle antennas in satellite mobile communications

    NASA Technical Reports Server (NTRS)

    Haddad, H. A.

    1948-01-01

    Several antenna design concepts, operating at UHF (821 to 825 MHz transmit and 866 to 870 MHz receive bands), with gain ranging between 6 and 12 dBic, that are suitable for land mobile vehicles are presented. The antennas may be used within CONUS and ALASKA to communicate to and from a geosynchronous satellite. Depending on the type of steering mechanism, the antennas are broken down into three categories; (1) electronically scanned arrays with phase shifters, (2) electronically switched arrays with switchable power dividers/combiners, and (3) mechanically steered arrays. The operating characteristics of two of these design concepts, one a conformal antenna with electronic beam steering and the other a nonconformal design with mechanical steering, were evaluated with regard to two and three satellite system. Cost estimates of various antenna concepts were made and plotted against their overall gain performance.

  15. Enhanced spectral efficiency using bandwidth switchable SAW filtering for mobile satellite communications systems

    NASA Technical Reports Server (NTRS)

    Peach, Robert; Malarky, Alastair

    1990-01-01

    Currently proposed mobile satellite communications systems require a high degree of flexibility in assignment of spectral capacity to different geographic locations. Conventionally this results in poor spectral efficiency which may be overcome by the use of bandwidth switchable filtering. Surface acoustic wave (SAW) technology makes it possible to provide banks of filters whose responses may be contiguously combined to form variable bandwidth filters with constant amplitude and phase responses across the entire band. The high selectivity possible with SAW filters, combined with the variable bandwidth capability, makes it possible to achieve spectral efficiencies over the allocated bandwidths of greater than 90 percent, while retaining full system flexibility. Bandwidth switchable SAW filtering (BSSF) achieves these gains with a negligible increase in hardware complexity.

  16. The design and networking of dynamic satellite constellations for global mobile communication systems

    NASA Technical Reports Server (NTRS)

    Cullen, Cionaith J.; Benedicto, Xavier; Tafazolli, Rahim; Evans, Barry

    1993-01-01

    Various design factors for mobile satellite systems, whose aim is to provide worldwide voice and data communications to users with hand-held terminals, are examined. Two network segments are identified - the ground segment (GS) and the space segment (SS) - and are seen to be highly dependent on each other. The overall architecture must therefore be adapted to both of these segments, rather than each being optimized according to its own criteria. Terrestrial networks are grouped and called the terrestrial segment (TS). In the SS, of fundamental importance is the constellation altitude. The effect of the altitude on decisions such as constellation design choice and on network aspects like call handover statistics are fundamental. Orbit resonance is introduced and referred to throughout. It is specifically examined for its useful properties relating to GS/SS connectivities.

  17. Consensus vs Broadcast in Communication Networks with Arbitrary Mobile Omission Faults

    E-print Network

    Godard, Emmanuel

    2011-01-01

    We compare the solvability of the Consensus and Broadcast problems in synchronous communication networks in which the delivery of messages is not reliable. The failure model is the mobile omission faults model. During each round, some messages can be lost and the set of possible simultaneous losses is the same for each round. We investigate these problems for the first time for arbitrary sets of possible failures. Previously, these sets were defined by bounding the numbers of failures. In this setting, we present a new necessary condition for the solvability of Consensus that unifies previous impossibility results in this area. This condition is expressed using Broadcastability properties. As a very important application, we show that when the sets of omissions that can occur are defined by bounding the numbers of failures, counted in any way (locally, globally, etc.), then the Consensus problem is actually equivalent to the Broadcast problem.

  18. The iPad and mobile technology revolution: benefits and challenges for individuals who require augmentative and alternative communication.

    PubMed

    McNaughton, David; Light, Janice

    2013-06-01

    The iPad and other mobile technologies provide powerful new tools to potentially enhance communication for individuals with developmental disabilities, acquired neurogenic disorders, and degenerative neurological conditions. These mobile technologies offer a number of potential benefits, including: (a) increased awareness and social acceptance of augmentative and alternative communication (AAC), (b) greater consumer empowerment in accessing AAC solutions, (c) increased adoption of AAC technologies, (d) greater functionality and interconnectivity, and (e) greater diffusion of AAC research and development. However, there remain a number of significant challenges that must be addressed if these benefits are to be fully realized: (a) to ensure the focus is on communication, not just technology, (b) to develop innovative models of AAC service delivery to ensure successful outcomes, (c) to ensure ease of access for all individuals who require AAC, and, (d) to maximize AAC solutions to support a wide variety of communication functions. There is an urgent need for effective collaboration among key stakeholders to support research and development activities, and to ensure the successful implementation of mobile technologies to enhance communication outcomes for individuals who require AAC and their families. PMID:23705813

  19. Security, Privacy, Trust, and Resource Management in Mobile and Wireless Communications

    Microsoft Academic Search

    Hassan Takabi; James B. D. Joshi

    2013-01-01

    Mobile cloud computing has grown out of two hot technology trends, mobility and cloud. The emergence of cloud computing and its extension into the mobile domain creates the potential for a global, interconnected mobile cloud computing environment that will allow the entire mobile ecosystem to enrich their services across multiple networks. We can utilize significant optimization and increased operating power

  20. Energy consumption in mobile phones: a measurement study and implications for network applications

    Microsoft Academic Search

    Niranjan Balasubramanian; Aruna Balasubramanian; Arun Venkataramani

    2009-01-01

    In this paper, we present a measurement study of the energy con- sumption characteristics of three widespread mobile networking technologies: 3G, GSM, and WiFi. We find that 3G and GSM in- cur a high tail energy overhead because of lingering in high power states after completing a transfer. Based on these measurements, we develop a model for the energy consumed

  1. Satellite applications to electric-utility communications needs. [land mobile satellite service

    NASA Technical Reports Server (NTRS)

    Horstein, M.; Barnett, R.

    1981-01-01

    Significant changes in the Nation's electric power systems are expected to result from the integration of new technology, possible during the next decade. Digital communications for monitor and control, exclusive of protective relaying, are expected to double or triple current traffic. A nationwide estimate of 13 Mb/s traffic is projected. Of this total, 8 Mb/s is attributed to the bulk-power system as it is now being operated (4 Mb/s). This traffic could be accommodated by current communications satellites using 3- to 4.5-m-diameter ground terminals costing $35,000 to $70,000 each. The remaining 5-Mb/s traffic is attributed to new technology concepts integrated into the distribution system. Such traffic is not compatible with current satellite technology because it requires small, low-cost ground terminals. Therefore, a high effective isotropic radiated power satellite, such as the one being planned by NASA for the Land Mobile Satellite Service, is required.

  2. Adaptive data rate SSMA system for personal and mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Ikegami, Tetsushi; Takahashi, Takashi; Arakaki, Yoshiya; Wakana, Hiromitsu

    1995-01-01

    An adaptive data rate SSMA (spread spectrum multiple access) system is proposed for mobile and personal multimedia satellite communications without the aid of system control earth stations. This system has a constant occupied bandwidth and has variable data rates and processing gains to mitigate communication link impairments such as fading, rain attenuation and interference as well as to handle variable data rate on demand. Proof of concept hardware for 6MHz bandwidth transponder is developed, that uses offset-QPSK (quadrature phase shift keying) and MSK (minimum shift keying) for direct sequence spread spectrum modulation and handle data rates of 4k to 64kbps. The RS422 data interface, low rate voice and H.261 video codecs are installed. The receiver is designed with coherent matched filter technique to achieve fast code acquisition, AFC (automatic frequency control) and coherent detection with minimum hardware losses in a single matched filter circuit. This receiver structure facilitates variable data rate on demand during a call. This paper shows the outline of the proposed system and the performance of the prototype equipment.

  3. 77 FR 28797 - Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-16

    ...FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 12 and 90 [DA 11-1838] Redundancy of Communications Systems: Backup Power Private...EA Licensing AGENCY: Federal Communications Commission. ACTION:...

  4. The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'07) 1-4244-1144-0/07/$25.00 2007 IEEE.

    E-print Network

    Vouyioukas, Demosthenes

    or simply SITs. The DVB-RCS Hub is vital for the operation of the DVB-RCS satellite communications network the new developments in satellite networks such as DVB-RCS. In fact, satellite communication systemsThe 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications

  5. The 17th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'06) 1-4244-0330-8/06/$20.00 c2006 IEEE

    E-print Network

    Boyer, Edmond

    The 17th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, coding, etc. for these communication systems is based on a reliable model of the radio propagation the performance of various radio communication systems in a time-variant propagation channel in the same test

  6. Proceedings of 5th Intl. Workshop on Mobile Multimedia Communications MoMuc'98 October 1214, 1998, Berlin Enhancing Wireless Internet Links

    E-print Network

    Polyzos, George C.

    Proceedings of 5th Intl. Workshop on Mobile Multimedia Communications MoMuc'98 October 12­14, 1998­style communications as an overlay, or IP ser­ vice directly. On the other hand, Wireless Local Area Net­ works (WLANs­ The authors are with the Center for Wireless Communications and the Computer Systems Laboratory, Department

  7. Throughput Optimization in Mobile Backbone Networks

    E-print Network

    Craparo, Emily M.

    This paper describes new algorithms for throughput optimization in a mobile backbone network. This hierarchical communication framework combines mobile backbone nodes, which have superior mobility and communication capability, ...

  8. A comparison of metropolitan and non-metropolitan employment characteristics: Indications of the size of non-metropolitan mobile communication services user classes

    NASA Technical Reports Server (NTRS)

    Wilcox, R. E.

    1985-01-01

    The similarities and differences between areas inside and outside U.S. metropolitan areas were evaluated in terms of their commercial/industrial and government employment characteristics. The comparison focuses on the levels, shares, and composition of employment in the commercial/industrial and government sectors that represent potential classes of land mobile communications users. The major findings of the analysis are as follows: (1) non-metropolitan commercial/industrial user classes of land mobile communication services exist in significant numbers; (2) the compositions of non-metropolitan and metropolitan commercial/industrial user classes of land mobile communication services closely resemble each other; (3) non-metropolitan areas have significant levels of the government user classes that represent potential markets for land mobile communication services; and (4) non-metropolitan local governments have a significantly larger proportion of their employment in the primary user classes of private land mobile radio service than do metropolitan local governments.

  9. Differential signaling spread-spectrum modulation of the LED visible light wireless communications using a mobile-phone camera

    NASA Astrophysics Data System (ADS)

    Chen, Shih-Hao; Chow, Chi-Wai

    2015-02-01

    Visible light communication (VLC) using spread spectrum modulation (SSM) and differential signaling (DS), detected by a mobile-phone camera is proposed and demonstrated for the first time to provide high immunity to background ambient light interference. The SSM signal provides the coding gain while the DS scheme enhances the clock recovery particular under high background ambient light. Experiment results confirm the feasibility of the proposed scheme, showing that the proposed system has 6-dB gain comparing with the traditional on-off keying (OOK) modulation under background ambient light of 3000 lux. The direct incident ambient light to the mobile-phone camera is 520 lux.

  10. Transformational Optimization of the Full Rate Speech Transcoder GSM 06.101

    E-print Network

    Ould Ahmedou, Mohameden

    1 Transformational Optimization of the Full Rate Speech Transcoder GSM 06.101 1 Motivation Since speech processing domain, the GSM full rate speech transcoder. In our approach, design space exploration

  11. How the mobile communication markets differ in China, the U.S., and Europe

    Microsoft Academic Search

    Xiaoni Zhang; Victor R. Prybutok

    2005-01-01

    Despite the 2001 downturn in the global telecommunications market, the mobile penetration rate in China is increasing due to the elimination or reduction of mobile connection fees. The mobile market worldwide is dynamic in terms of technology development, and competition is aggressive. The potential size and growth rate of the Chinese, U.S., and European mobile markets warrant examination of the

  12. OSI-compatible protocols for mobile-satellite communications: The AMSS experience

    NASA Technical Reports Server (NTRS)

    Moher, Michael

    1990-01-01

    The protocol structure of the international aeronautical mobile satellite service (AMSS) is reviewed with emphasis on those aspects of protocol performance, validation, and conformance which are peculiar to mobile services. This is in part an analysis of what can be learned from the AMSS experience with protocols which is relevant to the design of other mobile satellite data networks, e.g., land mobile.

  13. Radio Jamming Attacks Against Two Popular Mobile Networks

    Microsoft Academic Search

    Mika Stĺhlberg

    2000-01-01

    The dependence on Mobile Networks is growing. The success of the Internet was followed by Denial of Service attacks. What if the same happens to Mobile Networks? This paper gives an introduction to the concept of Radio Jamming and ex- plores jamming resistance of two popular mobile networks: GSM and WLAN. Radio interfaces of the two systems are analysed and

  14. Secure Architectures for Mobile Applications

    Microsoft Academic Search

    Cristian TOMA

    2007-01-01

    The paper presents security issues and architectures for mobile applications and GSM infrastructure. The article also introduces the idea of a new secure architecture for an inter-sector electronic wallet used in payments - STP4EW (Secure Transmission Protocol for Electronic Wallet)

  15. R&D of a Next Generation LEO System for Global Multimedia Mobile Satellite Communications

    NASA Astrophysics Data System (ADS)

    Morikawa, E.; Motoyoshi, S.; Koyama, Y.; Suzuki, R.; Yasuda, Y.

    2002-01-01

    Next-generation LEO System Research Center (NeLS) was formed in the end of 1997 as a research group under the Telecommunications Advancement Organization of Japan, in cooperation with the telecommunications operators, manufacturers, universities and governmental research organization. The aim of this project is to develop new technology for global multimedia mobile satellite communications services with a user data rate around 2Mbps for handy terminals. component of the IMT-2000, and the second generation of the big-LEO systems. In prosecuting this project, two-phase approach, phase 1 and phase 2, is considered. Phase 1 is the system definition and development of key technologies. In Phase 2, we plan to verify the developed technology in Phase 1 on space. From this year we shifted the stage to Phase 2, and are now developing the prototype of on-board communication systems for flight tests, which will be planed at around 2006. The satellite altitude is assumed to be 1200 km in order to reduce the number of satellites, to avoid the Van Allen radiation belts and to increase the minimum elevation angle. Ten of the circular orbits with 55 degree of inclination are selected to cover the earth surface from -70 to 70 degree in latitude. 12 satellites are positioned at regular intervals in each orbit. In this case, the minimum elevation angle from the user terminal can be keep more than 20 degree for the visibility of the satellite, and 15 degree for simultaneous visibility of two satellites. Then, NeLS Research Center was focusing on the development of key technologies as the phase 1 project. Four kinds of key technologies; DBF satellite antenna, optical inter-satellite link system, satellite network technology with on-board ATM switch and variable rate modulation were selected. Satellite Antenna Technology: Development of on-board direct radiating active phased array antenna with digital beam forming technology would be one of the most important breakthroughs for the satellite communication systems. Therefore, the experimental DBF network with 16 radiating elements was developed for confirming a basic signal processing performance. A/D sampled data are processed by using FPGA circuit for beam forming by real-time basis. Optical Inter-Satellite Link Technology: The inter-satellite link (ISL) technology is also important, because the inter-satellite network is essential to realize the low delay network connection for multimedia services. The optical ISL simulator was developed for the study of optical modem and optical tracking mechanism. And the sensitivity of 56 photons/bit at 10-9 of error rate has been achieved by employing the Erbium doped fiber amplifier, polarizing filter and narrow band optical filter. Coude path type, the active universal joint (AUJ) type and two flat mirror type of optical antenna mechanism were developed. Satellite Network Technology: For constructing this optical ISL ring, the utilization of wavelength division multiplexing (WDM) technology is envisaged. By applying WDM technology to the optical intra-orbital ISL, logical mesh connections can be achieved by assigning the appropriate wavelength for the links among satellites. By using inclined orbit, inter-orbital ISL connection can be keep continuously. Therefore, WDM technology is also applicable to the inter-orbital ISL network. The satellite ATM network simulator was developed in order to investigate the effect of delay fluctuation caused by the satellite constellations. This simulator works as real-time basis by using commercial ATM switches and personal computers. This simulator was installed Dijkstra's algorithm to determine satellite routing path in order to minimize the end-to-end delay time from the source terminal to the destination terminal. The satellite IP network simulator has been developed in order to evaluate the congestion of the multimedia traffic. Variable Rate Modulation Technology: Considering the propagation impairments in the mobile conditions, we employ the variable rate transmission, which maintains the communication service

  16. Low-mobility channel tracking for MIMO-OFDM communication systems

    NASA Astrophysics Data System (ADS)

    Pagadarai, Srikanth; Wyglinski, Alexander M.; Anderson, Christopher R.

    2013-12-01

    It is now well understood that by exploiting the available additional spatial dimensions, multiple-input multiple-output (MIMO) communication systems provide capacity gains, compared to a single-input single-output systems without increasing the overall transmit power or requiring additional bandwidth. However, these large capacity gains are feasible only when the perfect knowledge of the channel is available to the receiver. Consequently, when the channel knowledge is imperfect, as is common in practical settings, the impact of the achievable capacity needs to be evaluated. In this study, we begin with a general MIMO framework at the outset and specialize it to the case of orthogonal frequency division multiplexing (OFDM) systems by decoupling channel estimation from data detection. Cyclic-prefixed OFDM systems have attracted widespread interest due to several appealing characteristics not least of which is the fact that a single-tap frequency-domain equalizer per subcarrier is sufficient due to the circulant structure of the resulting channel matrix. We consider a low-mobility wireless channel which exhibits inter-block channel variations and apply Kalman tracking when MIMO-OFDM communication is performed. Furthermore, we consider the signal transmission to contain a stream of training and information symbols followed by information symbols alone. By relying on predicted channel states when training symbols are absent, we aim to understand how the improvements in channel capacity are affected by imperfect channel knowledge. We show that the Kalman recursion procedure can be simplified by the optimal minimum mean square error training design. Using the simplified recursion, we derive capacity upper and lower bounds to evaluate the performance of the system.

  17. Experimental Evaluation of the Impact of Network Frequency Synchronization on GSM Quality of Service During Handover

    E-print Network

    Bregni, Stefano

    Experimental Evaluation of the Impact of Network Frequency Synchronization on GSM Quality.barbieri@omnitelvodafone.it Abstract Poor accuracy of frequency references used in GSM Base Transceiver Stations (BTS) can lead synchronization affects GSM handover performance, leading to some degradation of quality of service. The speech

  18. Towards the Software Realization of a GSM Base Thierry Turletti, Hans Bentzen and David Tennenhouse

    E-print Network

    Turletti, Thierry

    Towards the Software Realization of a GSM Base Station Thierry Turletti, Hans Bentzen and David. This paper considers the software implementation of a GSM Base Transceiver Station (BTS) and analyzes the per be used to dimen­ sion systems, e.g., to estimate the number of software­based GSM channels that can

  19. Dveloppement et intgration d'une antenne relais GSM/3G dans un chargeur inductif

    E-print Network

    Dobigeon, Nicolas

    Développement et intégration d'une antenne relais GSM/3G dans un chargeur inductif Objectif du stage: intégration d'une antenne relais GSM/3G dans un chargeur inductif Lieu du stage: CONTINENTAL et état de l'art sur les systčmes relais GSM/3G: relais analogique par couplage en champ

  20. Location Leaks on the GSM Air Interface Denis Foo Kune, John Koelndorfer, Nicholas Hopper, Yongdae Kim

    E-print Network

    Dahlberg, E. Dan

    Location Leaks on the GSM Air Interface Denis Foo Kune, John Koelndorfer, Nicholas Hopper, Yongdae worldwide in 2010, of which 80% are GSM subscribers. Due to their use of the wireless medium within a small area, or absent from a large area by simply listening on the broadcast GSM channels

  1. Modeling Framelevel Errors in GSM Wireless Channels Ping Ji, Benyuan Liu, Don Towsley and Jim Kurose

    E-print Network

    Massachusetts at Amherst, University of

    1 Modeling Frame­level Errors in GSM Wireless Channels Ping Ji, Benyuan Liu, Don Towsley and Jim­level errors in GSM channels. One of these, the Markov­based Trace Analysis model (MTA), was developed for the purpose of modeling a GSM channel. The next two, k­th­order Markov models and hidden Markov models (HMMs

  2. Programme Specification MA GSM&J Programme Specification 2013/14, Page 1 of 9

    E-print Network

    Subramanian, Sriram

    Programme Specification MA GSM&J Programme Specification 2013/14, Page 1 of 9 1 of the Programme The attitude of Goldsmithing, Silversmithing, Metalwork and Jewellery (GSM&J) has shifted from picture. GSM&J provides an environment for exploring, in practical and theoretical ways, what it #12

  3. ROBUST SPEAKER VERIFICATION FROM GSM-TRANSCODED SPEECH BASED ON DECISION FUSION AND FEATURE TRANSFORMATION

    E-print Network

    Mak, Man-Wai

    ROBUST SPEAKER VERIFICATION FROM GSM-TRANSCODED SPEECH BASED ON DECISION FUSION AND FEATURE on the GSM-transcoded speech of 150 speakers from the HTIMIT corpus demon- strate that the proposed fusion. For exam- ple, speaker verification based on GSM, G.729, and G.723.1 resynthesized speech was studied in [1

  4. Location leaks on the GSM air interface Denis Foo Kune, John Koelndorfer, Nicholas Hopper, Yongdae Kim

    E-print Network

    Minnesota, University of

    Location leaks on the GSM air interface Denis Foo Kune, John Koelndorfer, Nicholas Hopper, Yongdae worldwide in 2010, of which 80% are GSM subscribers. Due to their use of the wireless medium area, or absent from a large area by simply listening on the broadcast GSM channels. With a combination

  5. CapacityAssignment Optimisation for Wireless GSM Cells D.D. Kouvatsos and S. Tantos

    E-print Network

    Ould-Khaoua, Mohamed

    Capacity­Assignment Optimisation for Wireless GSM Cells D.D. Kouvatsos and S. Tantos Performance framework for the capacity­assignment optimisation of a wireless GSM cell employing the RUP (Re approximation of an open queueing network model (QNM) of calls of a wireless GSM cell with RUP. Under

  6. An Empirical Study on Statistical Properties of GSM Telephone Call Arrivals

    E-print Network

    Bregni, Stefano

    An Empirical Study on Statistical Properties of GSM Telephone Call Arrivals Stefano Bregni, Senior and terminated call arrivals in sets of real GSM tele- phone traffic data (TIM, Italy), emphasizing results in planning and performance evaluation of cellular networks. Index Terms GSM, modified Allan variance

  7. DISTORTION-CLASS WEIGHTED ACOUSTIC MODELING FOR ROBUST SPEECH RECOGNITION UNDER GSM RPE-LTP CODING

    E-print Network

    Stern, Richard

    DISTORTION-CLASS WEIGHTED ACOUSTIC MODELING FOR ROBUST SPEECH RECOGNITION UNDER GSM RPE-LTP CODING-rate GSM RPE-LTP coding by combining two sets of acoustic models during recognition, one set trained on GSM distortion to the quantized long-term residual introduced by the RPE-LTP codec and discuss how

  8. Hybrid GPS-GSM Localization of Automobile Tracking System

    E-print Network

    Al-Khedher, Mohammad A

    2012-01-01

    An integrated GPS-GSM system is proposed to track vehicles using Google Earth application. The remote module has a GPS mounted on the moving vehicle to identify its current position, and to be transferred by GSM with other parameters acquired by the automobile's data port as an SMS to a recipient station. The received GPS coordinates are filtered using a Kalman filter to enhance the accuracy of measured position. After data processing, Google Earth application is used to view the current location and status of each vehicle. This goal of this system is to manage fleet, police automobiles distribution and car theft cautions.

  9. GSM Technology as a Communication Media for an Autonomous Unmanned Aerial Vehicle GSM Technology as a Communication Media for an

    E-print Network

    Doherty, Patrick

    suites. Data links, such as wireless Ethernet or radio modems that use open frequency bands are often infrastructure for remotely accessing, controlling and interacting with UAVs in an integrated and highly portable. A prototype network is presented, that was created between two UAVs and a ground operator using GPRS

  10. The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC'07) SUPPORTING FIRST PERSON SHOOTER GAMES IN WIRELESS LOCAL AREA

    E-print Network

    The 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications an affect on WLANs. As with most Internet application traffic, FPS games exhibit uplink/downlink asymmetry

  11. A comparison study of the uplink performance of W-CDMA and OFDM for mobile multimedia communications via LEO satellites

    Microsoft Academic Search

    A. Papathanassiou; A. K. Salkintzis; P. T. Mathiopoulos

    2001-01-01

    This article presents a comparison study of the uplink performance of two well-known transmission schemes, W-CDMA and OFDM, for mobile multimedia communications via LEO satellite. In order to provide a framework for a fair comparison we have considered for both schemes common parameters, including identical channel bandwidth, coding\\/decoding algorithms and similar net data rate. The values of these parameters have

  12. Cryptanalysis of the end-to-end security protocol for mobile communications with end-user identification\\/authentication

    Microsoft Academic Search

    YongBin Zhou; ZhenFeng Zhang; DengGuo Feng

    2005-01-01

    This letter shows that the end-to-end security protocol for mobile communications with end-user identification\\/authentication due to Chang et al., (2004) has a serious security flaw. We demonstrate this by presenting a simple but powerful impersonation attack against the protocol so that the protocol is insecure against impersonation attack. Hence, the protocol cannot achieve the claimed security. To overcome such a

  13. The application of a novel two-way mobile satellite communications and vehicle tracking system to the transportation industry

    Microsoft Academic Search

    I. M. Jacobs; A. Salmasi; T. J. Bernard

    1991-01-01

    A two-way mobile satellite communications and vehicle position reporting system currently operational in the US and Europe is described. The system characteristics and service operations are described in detail, and technical descriptions of the equipment and signal processing techniques are provided. The application of this technology to the land transportation industry, specifically the over-the-road truckload motor carrier segment, and the

  14. Performance of the unique-word-reverse-modulation type demodulator for mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Dohi, Tomohiro; Nitta, Kazumasa; Ueda, Takashi

    1993-01-01

    This paper proposes a new type of coherent demodulator, the unique-word (UW)-reverse-modulation type demodulator, for burst signal controlled by voice operated transmitter (VOX) in mobile satellite communication channels. The demodulator has three individual circuits: a pre-detection signal combiner, a pre-detection UW detector, and a UW-reverse-modulation type demodulator. The pre-detection signal combiner combines signal sequences received by two antennas and improves bit energy-to-noise power density ratio (E(sub b)/N(sub 0)) 2.5 dB to yield 10(exp -3) average bit error rate (BER) when carrier power-to-multipath power ratio (CMR) is 15 dB. The pre-detection UW detector improves UW detection probability when the frequency offset is large. The UW-reverse-modulation type demodulator realizes a maximum pull-in frequency of 3.9 kHz, the pull-in time is 2.4 seconds and frequency error is less than 20 Hz. The performances of this demodulator are confirmed through computer simulations and its effect is clarified in real-time experiments at a bit rate of 16.8 kbps using a digital signal processor (DSP).

  15. 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

    ...Communication Devices Featuring Digital Cameras, and Components Thereof...International Trade Commission. ACTION: Institution of investigation...communication devices featuring digital cameras, and components thereof by...communication devices featuring digital cameras, or [[Page 8113

  16. 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.

  17. Mobile Informal Learning

    Microsoft Academic Search

    Christian Glahn; Dirk Börner

    2010-01-01

    Mobile technologies play an important role in contemporary communication. Starting from mobile telephony, mobile devices are increasingly becoming ubiquitous devices for personal information management and communication through different channels. These new devices shape our perception of information, communication, participation, and learning. Moreover, new and smart mobile technology challenges the current views on education and learning more radically then the worldwide

  18. Proceedings of 5th Intl. Workshop on Mobile Multimedia Communications MoMuc'98 October 1214, 1998, Berlin Optimal Distributed Call Admission Control for

    E-print Network

    Kwon, Taekyoung

    ­ media services in mobile/wireless communication networks. Call admission control (CAC) is a key factor, Berlin Optimal Distributed Call Admission Control for Multimedia Services in Mobile Cellular Network in supporting successfully these services. In this paper, we propose a dis­ tributed call admission control

  19. A 90-nm CMOS Low-Power GSM\\/EDGE Multimedia-Enhanced Baseband Processor With 380MHz ARM926 Core and Mixed-Signal Extensions

    Microsoft Academic Search

    Thomas Lueftner; Joerg Berthold; Christian Pacha; Georg Georgakos; Guillaume Sauzon; Olaf Hoemke; Jurij Beshenar; Peter Mahrla; Knut Just; Peter Hober; Stephan Henzler; Doris Schmitt-Landsiedel; Andre Yakovleff; Axel Klein; Richard J. Knight; Pramod Acharya; Andre Bonnardot; Steffen Buch; Matthias Sauer

    2007-01-01

    To meet the widely varying speed and power requirements of multifunctional mobile devices, an appropriate combination of technology features, circuit-level low-power techniques, and system architecture is implemented in a GSM\\/Edge baseband processor with multimedia and mixed-signal extensions. Power reduction techniques and performance requirements are derived from an analysis of relevant use cases and applications. The 44 mm2 baseband processor is

  20. Mobility management in mobile IP

    NASA Astrophysics Data System (ADS)

    Medidi, Sirisha; Golshani, Forouzan

    2002-07-01

    There is an emerging interest in integrating mobile wireless communication with the Internet based on the Ipv6 technology. Many issues introduced by the mobility of users arise when such an integration is attempted. This paper addresses the problem of mobility management, i.e., that of tracking the current IP addresses of mobile terminals and sustaining active IP connections as mobiles move. The paper presents some architectural and mobility management options for integrating wireless access to the Internet. We then present performance results for Mobile IPv4, route optimization and Mobile IPv6.

  1. WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2006; 6:151170

    E-print Network

    Latchman, Haniph A.

    : medium access control (MAC); mobile ad hoc networks (MANETs); quality of service (QoS); fairness; energy environment monitoring, and collaborative computing. Since all the mobile nodes in MANETs use the same-routing activity. Third, in MANETs, mobile nodes are typically computationally limited and bat- tery powered, which

  2. Scenario driven requirement engineering for design and deployment of mobile communication networks

    Microsoft Academic Search

    Jan Markendahl; Bengt G. Mölleryd; Claes Beckman; Östen Mäkitalo

    2011-01-01

    The numbers of users and usage of mobile data service are increasing dramatically due to the introduction of smartphones and mobile broadband dongles. For the next decade the mobile broadband market is expected to grow and reach a level where the average data consumption per user is orders of magnitude greater than today. For the telecom industry it is a

  3. A Colpitts Oscillator Design for a GSM Base Station Synthesizer

    Microsoft Academic Search

    J. Steinkamp; F. Henkel; P. Waldow; O. Pettersson; C. Hedenas; B. Medin

    2007-01-01

    This paper presents the design of a VCO using a Colpitts topology. The VCO system is fully integrated and suitable to operate in GSM base station synthesizers. The challenges and requirements for this application will be discussed and the possibility of achieving the performance of the oscillator will be demonstrated. The topology of the VCO core is a varactor tuned

  4. GMSK linearization and structured channel estimate for GSM signals

    Microsoft Academic Search

    Jen-Wei Liang; Boon C. Ng; J.-T. Chen; A. Paulraj

    1997-01-01

    GMSK is a spectrum-efficient modulation scheme, and it is adopted as the modulation standard of GSM systems. However, because of its phase modulation, Gaussian filtering, and partial response signaling properties, GMSK is not a linear modulation. We present a linear approximation of GMSK signals at T\\/2 fractional spacing. The partial response channel with a memory length of 3 symbol periods,

  5. Ericsson\\/Mannesmann GSM field-trials with adaptive antennas

    Microsoft Academic Search

    S. Anderson; U. Forssen; J. Karlsson; T. Witzschel; P. Fischer; A. Krug

    1997-01-01

    This paper describes Ericsson's GSM testbed for evaluation of adaptive antenna technology and joint field-trials made by Ericsson and Mannesmann Mobilfunk. The implementation principles and algorithms are described together with the field-trial setup. The field-trials was carried out in Dusseldorf, Germany, by Mannesmann Mobilfunk and Ericsson. The paper also presents results from the field-tests

  6. A matrix-form GSM-CFD solver for incompressible fluids and its application to hemodynamics

    NASA Astrophysics Data System (ADS)

    Yao, Jianyao; Liu, G. R.

    2014-10-01

    A GSM-CFD solver for incompressible flows is developed based on the gradient smoothing method (GSM). A matrix-form algorithm and corresponding data structure for GSM are devised to efficiently approximate the spatial gradients of field variables using the gradient smoothing operation. The calculated gradient values on various test fields show that the proposed GSM is capable of exactly reproducing linear field and of second order accuracy on all kinds of meshes. It is found that the GSM is much more robust to mesh deformation and therefore more suitable for problems with complicated geometries. Integrated with the artificial compressibility approach, the GSM is extended to solve the incompressible flows. As an example, the flow simulation of carotid bifurcation is carried out to show the effectiveness of the proposed GSM-CFD solver. The blood is modeled as incompressible Newtonian fluid and the vessel is treated as rigid wall in this paper.

  7. Initial experience with a handheld device digital imaging and communications in medicine viewer: OsiriX mobile on the iPhone.

    PubMed

    Choudhri, Asim F; Radvany, Martin G

    2011-04-01

    Medical imaging is commonly used to diagnose many emergent conditions, as well as plan treatment. Digital images can be reviewed on almost any computing platform. Modern mobile phones and handheld devices are portable computing platforms with robust software programming interfaces, powerful processors, and high-resolution displays. OsiriX mobile, a new Digital Imaging and Communications in Medicine viewing program, is available for the iPhone/iPod touch platform. This raises the possibility of mobile review of diagnostic medical images to expedite diagnosis and treatment planning using a commercial off the shelf solution, facilitating communication among radiologists and referring clinicians. PMID:20567992

  8. The Mobile College Community: A Study of Adult Learners' Adoption and Use of Digital Communication Technologies on the Campuses of Florida's Community Colleges

    ERIC Educational Resources Information Center

    Weidert, John William

    2012-01-01

    Rapid advancements in technology and the proliferation of mobile communication devices available in the marketplace require that community college administrators and teachers better understand levels of digital communication technology adoption and how adult learners currently use them. Such an understanding is necessary to developing the…

  9. 2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications One-bit Time Reversal for WLAN Applications

    E-print Network

    Papanicolaou, George C.

    2005 IEEE 16th International Symposium on Personal, Indoor and Mobile Radio Communications One applications. We apply it to radio waves and demonstrate that it can preserve the spatial focusing properties for multiple-input/single-output (MISO) underwater communication systems. In fact, several experiments

  10. All-digital multicarrier demodulators for on-board processing satellites in mobile communication systems

    NASA Astrophysics Data System (ADS)

    Yim, Wan Hung

    Economical operation of future satellite systems for mobile communications can only be fulfilled by using dedicated on-board processing satellites, which would allow both cheap earth terminals and lower space segment costs. With on-board modems and codecs, the up-link and down-link can be optimized separately. An attractive scheme is to use frequency-division multiple access/single chanel per carrier (FDMA/SCPC) on the up-link and time division multiplexing (TDM) on the down-link. This scheme allows mobile terminals to transmit a narrow band, low power signal, resulting in smaller dishes and high power amplifiers (HPA's) with lower output power. On the up-link, there are hundreds to thousands of FDM channels to be demodulated on-board. The most promising approach is the use of all-digital multicarrier demodulators (MCD's), where analog and digital hardware are efficiently shared among channels, and digital signal processing (DSP) is used at an early stage to take advantage of very large scale integration (VLSI) implementation. A MCD consists of a channellizer for separation of frequency division multiplexing (FDM) channels, followed by individual modulators for each channel. Major research areas in MCD's are in multirate DSP, and the optimal estimation for synchronization, which form the basis of the thesis. Complex signal theories are central to the development of structured approaches for the sampling and processing of bandpass signals, which are the foundations in both channellizer and demodulator design. In multirate DSP, polyphase theories replace many ad-hoc, tedious and error-prone design procedures. For example, a polyphase-matrix deep space network frequency and timing system (DFT) channellizer includes all efficient filter bank techniques as special cases. Also, a polyphase-lattice filter is derived, not only for sampling rate conversion, but also capable of sampling phase variation, which is required for symbol timing adjustment in all-digital demodulators. In modulation schemes, a systematic survey is reported, based on two expressions that includes all formats in linear and constant envelope modulation. In synchronization techniques, classifications according to the criterion of statistical optimization, the data dependecy, and the method of parameter extraction, reflect the inherent complexity and performance of numerous existing algorithms. The designs of two new algorithms are presented: a differential decision frequency error detector that is simple and fast; a dual-comb-filter frequency/timing error detector that is targeted at VLSI implementation. The real-time implementation of a complete 4 x 16 kb/s MCD for the T-SAT project is described in detail, which proved many of the structured design concepts developed in this thesis. The requirements of software tools for various levels of simulation in multirate DSP and communications are analyzed. This led to the implementation of a data-flow oriented simulation system, which was used in all research work in the thesis.

  11. Communication.

    ERIC Educational Resources Information Center

    Strauss, Andre

    The following essays on communication are presented: communication as a condition of survival, communication for special purposes, the means of transmission of communication, communication within social and economic structures, the teaching of communication through the press, the teaching of modern languages, communication as a point of departure,…

  12. Energy locality: processing\\/communication\\/interface tradeoffs to optimize energy in mobile systems

    Microsoft Academic Search

    D. Siewiorek

    2001-01-01

    Summary form only given, as follows. As computers continue to shrink, research and commercial interest in mobile\\/wearable computing is rapidly growing. Unlike traditional desktop computing in which the user is required to come to the computer, mobile computing brings the computer to the user. Mobile\\/wearable computers represent the next evolutionary step in the trend toward more people-centric computing. One of

  13. 76 FR 17347 - Aviation Communications

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-29

    ...Aeronautical Mobile Satellite (Route) Service...air-to-air communications in Hawaii...Aeronautical Mobile Satellite (Route) Service...air-to-air communications in Hawaii...requiring that mobile satellite systems accord...to AMS(R)S communications in...

  14. The logic of communication: roles for mobile transcription factors in plants.

    PubMed

    Long, Yuchen; Scheres, Ben; Blilou, Ikram

    2015-02-01

    Mobile transcription factors play many roles in plant development. Here, we compare the use of mobile transcription factors as signals with some canonical signal transduction processes in prokaryotes and eukaryotes. After an initial survey, we focus on the SHORT-ROOT pathway in Arabidopsis roots to show that, despite the simplicity of the concept of mobile transcription factor signalling, many lines of evidence reveal a surprising complexity in control mechanisms linked to this process. We argue that these controls bestow precision, robustness, and versatility on mobile transcription factor signalling. PMID:25635110

  15. Plants Respond to GSM-Like Radiation.

    PubMed

    Vian, Alain; Faure, Catherine; Girard, Sébastien; Davies, Eric; Hallé, Francis; Bonnet, Pierre; Ledoigt, Gérard; Paladian, Françoise

    2007-11-01

    In this article, we propose that an organism's general architecture is of primary importance for its ability to perceive electromagnetic radiation. Animals develop mainly as volumes for internal assimilation and appendages to increase their mobility, while plants develop as surfaces to optimize interaction with the environment. As a consequence, the proportion of cells directly interacting with EMF radiation at the organism/environment interface is much higher in plants than it is in animals, making them especially suited to study EMF effects on life. PMID:19704547

  16. 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

    ...Communication Devices Featuring Digital Cameras, and Components Thereof...International Trade Commission. ACTION: Notice...communication devices featuring digital cameras, and components thereof...Office of the Secretary. This action is taken under the...

  17. 75 FR 65654 - In the Matter of: Certain Mobile Telephones and Wireless Communication Devices Featuring Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-26

    ...Communication Devices Featuring Digital Cameras, and Components Thereof...International Trade Commission. ACTION: Notice...communication devices featuring digital cameras, and components thereof...the form of an order. This action is taken under the...

  18. A medical application integrating remote 3D visualization tools to access picture archiving and communication system on mobile devices.

    PubMed

    He, Longjun; Ming, Xing; Liu, Qian

    2014-04-01

    With computing capability and display size growing, the mobile device has been used as a tool to help clinicians view patient information and medical images anywhere and anytime. However, for direct interactive 3D visualization, which plays an important role in radiological diagnosis, the mobile device cannot provide a satisfactory quality of experience for radiologists. This paper developed a medical system that can get medical images from the picture archiving and communication system on the mobile device over the wireless network. In the proposed application, the mobile device got patient information and medical images through a proxy server connecting to the PACS server. Meanwhile, the proxy server integrated a range of 3D visualization techniques, including maximum intensity projection, multi-planar reconstruction and direct volume rendering, to providing shape, brightness, depth and location information generated from the original sectional images for radiologists. Furthermore, an algorithm that changes remote render parameters automatically to adapt to the network status was employed to improve the quality of experience. Finally, performance issues regarding the remote 3D visualization of the medical images over the wireless network of the proposed application were also discussed. The results demonstrated that this proposed medical application could provide a smooth interactive experience in the WLAN and 3G networks. PMID:24705800

  19. Supplanting copper : pricing and quality of GSM telecom services in Africa

    E-print Network

    Oyeyinka, Oyebanke (Oyebanke Nihinlolawa)

    2008-01-01

    Introduction: The mobile phone is one of the greatest innovations of the 2 0 th century. It allows a user to communicate information - data and voice - regardless of their geographical location. Its importance has grown ...

  20. PHYSICAL REVIEW E 85, 016113 (2012) Consensus in networks of mobile communicating agents

    E-print Network

    Diaz-Guilera, Albert

    2012-01-01

    reference for a better understanding of the behavior of populations of mobile agents. DOI: 10.1103/Phys Baronchelli1,2 and Albert D´iaz-Guilera3 1 Departament de F´isica i Enginyeria Nuclear, Universitat Polit 2011; revised manuscript received 25 November 2011; published 23 January 2012) Populations of mobile

  1. Improving Mobile Solution Workflows and Usability Using Near Field Communication Technology

    Microsoft Academic Search

    Päivi Jaring; Vili Törmänen; Erkki Siira; Tapio Matinmikko

    2007-01-01

    Organisations want nowadays more controlled processes and easily usable solutions, but achieving them requires winning many challenges. Radio Frequency Identification (RFID) based technology has been proposed for im- proving mobile solution workflows and usability. NFC (Near Field Communi- cation) technology is based on integrating RFID on mobile devices. This paper identifies how NFC based systems could be used to improve

  2. Evaluation Of Dynamic Pricing In Mobile Communication Systems Elena Fitkov-Norris and Ahmad Khanifar

    E-print Network

    Haddadi, Hamed

    installation of new infrastructure. While such strategies enable the networks to meet peak-hour demand optimisation. 1. Introduction. The mobile cellular telephony market has expanded rapidly over the past decade. In the UK, at the end of the first quarter of 1999, mobile phone penetration was almost 30% - up by 5

  3. Consolidation vs fragmentation : The case of the European mobile communications market

    Microsoft Academic Search

    Jason Whalley; Peter Curwen

    2005-01-01

    Purpose – In recent times there has been much speculation about the need for consolidation in the European telecommunications industry. However, consolidation has not happened as expected with the market fragmenting instead. This article seeks to explain this phenomenon. Design\\/methodology\\/approach – A distinction is made between second and third generation mobile technologies, and the ownership of mobile licences in 41

  4. Life cycle assessment of the mobile communication system UMTS: towards eco-efficient systems

    Microsoft Academic Search

    M. Stutz; M. F. Emmenegger; R. Frischknecht; M. Guggisberg; R. Witschi; T. Otto

    2003-01-01

    Telecommunication providers and telecommunication manufacturers are getting ready to implement the third generation (3G) mobile telecommunication systems known as UMTS (Universal Mobile Telecommunication System) in Europe. Next to the technical problems involved, no statement regarding the sustainability of the UMTS can yet be made. In a joint effort Motorola, Swisscom, Deutsche Telekom and ESU-services have carried out an evaluation of

  5. Short communication: Genetic evaluation of mobility for Brown Swiss dairy cattle

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic parameters were estimated for mobility score and 16 linear type traits of Brown Swiss dairy cattle. Mobility is an overall assessment trait that measures a cow’s ability to move as well as the structure of her feet, pasterns, and legs. Scores from 50 to 99 were assigned by appraisers for the...

  6. Traffic Capacity of Three Types of Common-User Mobile Radio Communication Systems

    Microsoft Academic Search

    L. Schiff

    1970-01-01

    The traffic-carrying capability of three types of common-user mobile radio systems are derived and compared; they are also compared with a private-user system. The systems considered make use of multichannel capability for mobile units or a dispersed array of base stations, or both.

  7. Simultaneous cancellation of cross interference and ISI in CDMA mobile radio communications

    Microsoft Academic Search

    A. Klein; P. W. Baier

    1992-01-01

    In this paper, data estimation in the uplink of a synchronous mobile radio system applying CDMA is considered. In mobile radio systems applying CDMA, multipath propagation leads on the one hand to ISI and on the other hand, together with time-variance, to cross interference between the signals of different users, regardless whether the user codes are chosen orthogonal or not.

  8. Patient-Provider Communications in Outpatient Clinic Settings: A Clinic-Based Evaluation of Mobile Device and Multimedia Mediated Communications for Patient Education

    PubMed Central

    Schooley, Benjamin; San Nicolas-Rocca, Tonia

    2015-01-01

    Background Many studies have provided evidence of the importance of quality provider-patient communications and have suggested improvements to patient understanding by using video-based instruction. Objective The objective of this study was to understand how mobile information technology assisted video and three-dimensional (3D) image instruction, provided by a health care worker, influences two categories of outcome: (1) patient understanding of information about their condition and detailed medical discharge instructions; and (2) patient perceptions and attitudes toward their health care providers, which included physicians, nurses, and staff. We hypothesize that video and 3D image instruction, provided on a mobile, tablet hardware platform, will improve patient understanding about the diagnostic testing, diagnoses, procedures, medications, and health topics provided to them. We also propose that use of the tablet/video combination will result in improved attitudinal evaluation by patients of their providers and the treatment plan. Methods This study evaluated a hospital clinic-based trial (patient N=284) of video and 3D image instruction, provided on a mobile, tablet hardware platform, and its potential to improve patient understanding about the diagnostic testing, diagnoses, procedures, medications, and health topics provided to them. Results Results showed strong evidence that the system was perceived as helpful for improving patient understanding, and that it improved communication between physicians and patients (P<.001). The advanced age of some patients had no effect on their perceptions of the tablet-based mediation. Physician comments provided useful insights on effective use of such systems in the future. Implications for further development and future research are discussed. Conclusions This study added to the body of evidence that computer-assisted video instructional systems for patients can improve patient understanding of medical instructions from their health care providers and assist with patient compliance. In addition, such systems can be appealing to both patient and provider. PMID:25583145

  9. Color-filter-free spatial visible light communication using RGB-LED and mobile-phone camera.

    PubMed

    Chen, Shih-Hao; Chow, Chi-Wai

    2014-12-15

    A novel color-filter-free visible-light communication (VLC) system using red-green-blue (RGB) light emitting diode (LED) and mobile-phone camera is proposed and demonstrated for the first time. A feature matching method, which is based on the scale-invariant feature transform (SIFT) algorithm for the received grayscale image is used instead of the chromatic information decoding method. The proposed method is simple and saves the computation complexity. The signal processing is based on the grayscale image computation; hence neither color-filter nor chromatic channel information is required. A proof-of-concept experiment is performed and high performance channel recognition is achieved. PMID:25607019

  10. Combined GMSK and 8PSK modulator for GSM and EDGE

    Microsoft Academic Search

    Peter Bode; Alexander Lampe; Markus Helfenstein

    2003-01-01

    An efficient digital GMSK\\/8PSK I\\/Q signal modulator for GSM\\/EDGE is presented. The solution is based on Laurent's approximation of the non-linear GMSK modulator by a bank of linear, pre-encoded modulators, thus enabling burst shaping in the I\\/Q domain and therefore solving the problem of power ramping. The solution is compatible to all major transmitter architectures offering an I\\/Q interface.

  11. A Novel Application of the Phone Card and Its Authentication in Mobile Communications

    Microsoft Academic Search

    Cheng-chi Lee; Min-shiang Hwang; Wei-pang Yang

    1999-01-01

    The Subscriber Identity Module (SIM) is conventionally used in wireless communi-cation systems. However, several limitations involving SIM significantly reduce public ac-cess in wireless communications. This study examined the feasibility of using public tele-phone cards in wireless communications. This novel application retains the merits of SIM. Among the relevent issues addressed are location tracking of the user, authentication of the phone

  12. Challenges of real-time IP support in GSM\\/EDGE radio access network

    Microsoft Academic Search

    Dalibor Turina

    2000-01-01

    The next, evolutionary step for GSM\\/EDGE wireless system, includes a definition of the so-called GSM\\/EDGE radio access network (GERAN) in the coming releases of the standard. It enables the common evolution of GSM and TDMA\\/136 towards the third generation wireless systems. To successfully meet the requirements, the third-generation wireless systems must be designed to offer a multitude of services, providing

  13. Design, Installation and Execution of a Security Agent for Mobile Stations

    Microsoft Academic Search

    William G. Sirett; John A. Macdonald; Keith Mayes; Constantinos Markantonakis

    2006-01-01

    In this paper we present a methodology and protocol for es- tablishing a security context between a Mobile Operator's application server and a GSM\\/UMTS SIM card. The methodology assumes that the already issued Mobile Station is capable but unprepared. The proposed scheme creates a secure entity within the Mobile Station \\\\Over The Air\\

  14. HIDMN: A Host and Network-Based Intrusion Detection for Mobile Networks

    Microsoft Academic Search

    Shahriar Bijani

    2008-01-01

    Network-based methods of intrusion detection alone are not adequate to encounter current and future threats in mobile networks. In this paper, we introduce HIDMN, a host and network-based intrusion detection and prevention system for mobile networks. In addition, we outline some patterns for significant attacks in the GSM mobile network. This system can detect most attacks which we divide them

  15. Mobile phone measurement including the antenna

    Microsoft Academic Search

    Mikael B. Knudsen; Gert F. Pedersen; Bo G. H. Olsson; Kim Olesen

    2000-01-01

    Some investigations of a test method for validating the mobile handset proposed by Telia has been made. Test results of 10 commercially available GSM handsets measured in the Telia test setup has been compared with measurements of the power, based on 3D radiation pattern measurements performed in an anechoic room. Comparing just the transmitted power of the 10 tested phones

  16. c 2011 Kurchi Subhra Hazra GROUP FORMATION AND COMMUNICATION IN MOBILE WI-FI

    E-print Network

    Nahrstedt, Klara

    -Champaign, 2011 Urbana, Illinois Adviser: Professor Klara Nahrstedt #12;ABSTRACT Use of Wi-Fi-capable mobile Professor Klara Nahrstedt, with- out whose constant guidance and support, this work would not have been

  17. Adaptive Resource Allocation for Statistical QoS Provisioning in Mobile Wireless Communications and Networks

    E-print Network

    Du, Qinghe

    2012-02-14

    -QoS requirements for various mobile wireless services. However, many re- search works for adaptive resource allocations in wireless networks mainly focused on the following two types of applications: 1) which can tolerate infinite delay; 2) which can...

  18. Connection-information-based connection rerouting for connection-oriented mobile communication networks

    NASA Astrophysics Data System (ADS)

    Song, Minho; Choi, Yanghee; Kim, Chongsang

    1998-06-01

    To date, various connection rerouting methods for connection-oriented mobile networks have been proposed. The previous methods, however, are limited to specific topologies or environments. In this paper, we propose the connection-information-based rerouting widely applicable to various connection-oriented mobile networks. This method requires neither a specific topology nor a complex connection, enables fast rerouting, provides appropriate route optimality, and can be extended easily.

  19. An Investigation into the Use of 3G Mobile Communications to Provide Telehealth Services in Rural KwaZulu-Natal

    PubMed Central

    Mars, Maurice

    2015-01-01

    Abstract Background: We investigated the use of third-generation (3G) mobile communications to provide telehealth services in remote health clinics in rural KwaZulu-Natal, South Africa. Materials and Methods: We specified a minimal set of services as our use case that would be representative of typical activity and to provide a baseline for analysis of network performance. Services included database access to manage chronic disease, local support and management of patients (to reduce unnecessary travel to the hospital), emergency care (up to 8?h for an ambulance to arrive), e-mail, access to up-to-date information (Web), and teleclinics. We made site measurements at a representative set of health clinics to determine the type of coverage (general packet radio service [GPRS]/3G), its capabilities to support videoconferencing (H323 and Skype™ [Microsoft, Redmond, WA]) and audio (Skype), and throughput for transmission control protocol (TCP) to gain a measure of application performance. Results: We found that none of the remote health clinics had 3G service. The GPRS service provided typical upload speed of 44 kilobits per second (Kbps) and download speed of 64?Kbps. This was not sufficient to support any form of videoconferencing. We also observed that GPRS had significant round trip time (RTT), in some cases in excess of 750?ms, and this led to slow start-up for TCP applications. Conclusions: We found audio was always so broken as to be unusable and further observed that many applications such as Web access would fail under conditions of very high RTT. We found some health clinics were so remote that they had no mobile service. 3G, where available, had measured upload speed of 331?Kbps and download speed of 446?Kbps and supported videoconferencing and audio at all sites, but we frequently experienced 3G changing to GPRS. We conclude that mobile communications currently provide insufficient coverage and capability to provide reliable clinical services and would advocate dedicated wireless services where reliable communication is essential and use of store and forward for mobile applications. PMID:24926731

  20. Designing public safety mobile applications for disconnected, interrupted, and low bandwidth communication environments

    Microsoft Academic Search

    P. Erickson; A. Weinert; P. Breimyer; M. Samperi; J. Huff; C. Parra; S. Miller

    2013-01-01

    Public Safety emergency communication systems are crucial to effective incident and disaster response. Lack of situational awareness and communications are of the most cited factors that hamper Public Safety's ability to make critical decisions. In partnership with the Department of Homeland Security Science and Technology Directorate ({DHS} {S\\\\&T)}, {MIT} Lincoln Laboratory ({MIT} {LL)} developed the Next-Generation Incident Command System ({NICS)}