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1

Mobile station locating in GSM  

Microsoft Academic Search

The positioning of a mobile station (MS) will become mandatory in the US to support wireless emergency calls in the near future. Also, lots of other applications are foreseen for the location service, when implemented. In this paper the authors study the feasibility of the Global System for Mobile Communications (GSM) and MS location. The TDMA based GSM system offers

Marko Silventoinen; T. Rantalainen

1995-01-01

2

Overview of GSM: The Global System for Mobile Communications  

Microsoft Academic Search

this paper I have tried to give an overview of the GSM system. As with any overview, andespecially one covering a standard over 6000 pages long, there are many details missing. I hope Ihave given the general flavor of GSM and the philosophy behind its design. It was a monumentaltask that the original GSM committee undertook, and one that has

John Scourias

1996-01-01

3

Secure communication mechanisms for GSM networks  

Microsoft Academic Search

With the advance of wireless communications technology, mobile communications has become more convenient than ever. However, because of the openness of wireless communications, the protection of the privacy between communicating parties is becoming a very important issue. We focus on the security of the Global System for Mobile communication (GSM) networks. A secure communication architecture for the GSM network is

Chi-Chun Lo; Yu-Jen Chen

1999-01-01

4

Effect of global system for mobile communication (GSM) microwave exposure on blood-brain barrier permeability in rat  

Microsoft Academic Search

We investigated the effects of global system for mobile communication (GSM) microwave exposure on the permeability of the\\u000a blood-brain barrier using a calibrated microwave exposure system in the 900 MHz band. Rats were restrained in a carousel of\\u000a circularly arranged plastic tubes and sham-exposed or microwave irradiated for a duration of 4 h at specific brain absorption\\u000a rates (SAR) ranging

K. Fritze; C. Sommer; B. Schmitz; G. Mies; K.-A. Hossmann; M. Kiessling; C. Wiessner

1997-01-01

5

Mobility and security management in the GSM system and some proposed future improvements  

Microsoft Academic Search

Important aspects of mobility and security in the Global System for Mobile communications (GSM) system are discussed in this paper. Mobility management functions are broadly categorized into three groups: a) mobile turned on, b) mobile turned off, and c) mobile in conversation. The paper first outlines the mobile synchronization sequence followed by its mobility functions: mobile identification, authentication, international mobile

ASHA MEHROTRA; LEONARD S. GOLDING

1998-01-01

6

Mobility Detection Using Everyday GSM Traces  

Microsoft Academic Search

Recognition of everyday physical activities is difficult due to the challenges of building informative, yet unobtrusive sensors. The most widely deployed and used mobile computing device today is the mobile phone, which presents an obvious candidate for recognizing activities. This paper explores how coarse-grained GSM data from mobile phones can be used to recognize high-level properties of user mobility, and

Timothy Sohn; Alex Varshavsky; Anthony Lamarca; Mike Y. Chen; Tanzeem Choudhury; Ian E. Smith; Sunny Consolvo; Jeffrey Hightower; William G. Griswold; Eyal De Lara

2006-01-01

7

Instant Ciphertext-Only Cryptanalysis of GSM Encrypted Communication  

Microsoft Academic Search

In this paper we present a very practical ciphertext-only cryptanalysis of GSM encrypted communication, and various active at- tacks on the GSM protocols. These attacks can even break into GSM networks that use \\

Elad Barkan; Eli Biham; Nathan Keller

2003-01-01

8

On Accessing GSM-enabled Mobile Sensors Zissis K. Plitsis, #  

E-print Network

On Accessing GSM-enabled Mobile Sensors Zissis K. Plitsis, # Ioannis Fudos, Evaggelia Pitoura, zarras}@cs.uoi.gr Abstract In this paper, we propose a middleware framework that unifies access to GSM discuss a particular instance where a GSM-enabled camera with temperature, and motion detection sensors

Fudos, Ioannis

9

NFC Mobile Transactions and Authentication Based on GSM Network  

Microsoft Academic Search

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

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

2010-01-01

10

Thin internal GSM\\/DCS patch antenna for a portable mobile terminal  

Microsoft Academic Search

A novel internal dual-band patch antenna with a small thickness of 3 mm for application in Global System for Mobile Communication\\/Digital Communication System (GSM\\/DCS) mobile terminals such as the mobile phone or Personal Digital Assistant (PDA) phone is presented. The patch antenna occupies an area of 15×60 mm2, with its top patch embedded with a simple T-shaped slit, which separates

Kin-Lu Wong; Yuan-Chih Lin; Ting-Chih Tseng

2006-01-01

11

Dual-band planar inverted F antenna for GSM\\/DCS mobile phones  

Microsoft Academic Search

A compact dual-band planar inverted F antenna suitable for the application as a global system for mobile communication\\/digital communication system (GSM\\/DCS) dual-band mobile phone internal antenna is proposed and implemented. The proposed antenna has three resonant elements, two meandered metallic strips of slightly different lengths and one nearly-rectangular patch, which are printed on a supporting FR4 substrate and arranged in

Shih-Huang Yeh; Kin-Lu Wong; Tzung-Wern Chiou; Shyh-Tirng Fang

2003-01-01

12

Positioning GSM telephones  

Microsoft Academic Search

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

Christopher Drane; Malcolm Macnaughtan; Craig Scott

1998-01-01

13

Communication Systems Chair of Communication Systems  

E-print Network

of GSM overview ­ GSM interfaces ­ GSM network components Mobile switching center,visitor location;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

Schindelhauer, Christian

14

The Use of SS7 and GSM to Support High Density Personal Communications  

Microsoft Academic Search

\\u000a The combination of high user density, high mobility and enhanced network capabilities in Personal Communication Networks (PCN)\\u000a will generate significant network signaling. This paper presents an organized method for quantifying the Signaling System\\u000a Number 7 (SS7) traffic load associated with terminal mobility when the Pan-European standard GSM is used for PCN. We also\\u000a quantify the relative switching cost of PCN

Kathleen S. Meier-Hellstern; Eduardo Alonso; Douglas R. O’Neil

15

Analysis of the influence of the power control and discontinuous transmission on RF exposure with GSM mobile phones  

Microsoft Academic Search

Biological studies and, in particular, epidemiological ones require the estimation of the RF exposure induced by a mobile phone. Due to the different techniques used by global system mobile (GSM) and digital communication system (DCS) such as power control and discontinuous transmission, the power emitted by a handset is largely variable. As these parameters depend on the environment and the

Joe Wiart; Christian Dale; Ada Victoria Bosisio; Alain Le Cornec

2000-01-01

16

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

E-print Network

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

Ricci, Francesco

17

Updating Directions of Arrival in a GSM-Based SDMA Mobile Radio System  

E-print Network

Updating Directions of Arrival in a GSM-Based SDMA Mobile Radio System Rupert Stutzle, Jurgen Gotze multiple access SDMA mobile radio system, di erent mobile users use the same spectrum and are separated. In this paper an algorithm for updating the DOAs in a GSM-based SDMA mobile radio system is presented. It makes

Götze, Jürgen

18

The use of SS7 and GSM to support high density personal communications  

Microsoft Academic Search

The authors present an organized method for quantifying the Signaling System 7 (SS7) traffic load associated with terminal mobility when the pan-European standard GSM is used for personal communication networks (PCNs). They use CCIR parameters for an extremely dense, outdoor center-city pedestrian environment to illustrate the possible heavy signaling load. Using the example parameters, the additional SS7 network burden is

KATHLEEN S. MEIER-HELLSTERN; EDUARDO ALONSO; DOUGLAS R. O'NEIL

1992-01-01

19

Mobile station emergency locating in GSM  

Microsoft Academic Search

The positioning of a mobile station (MS) will become mandatory in the US in the near future to support enhanced emergency calls (E911). Also a lot of other applications are foreseen for the location service, when implemented. In the US a five-year, three-phase implementation of the E911 services is the most likely scenario. The authors study the feasibility of the

Marko I. Silventoinen; T. Rantalainen

1996-01-01

20

Overview of the GSM system and protocol architecture  

Microsoft Academic Search

The global system for mobile telecommunications (GSM), which provides terminal mobility, with personal mobility provided through the insertion of a subscriber identity module (SIM) into the GSM network, is discussed. Cellular mobile communications, the cellular network infrastructure, and the specification of network databases and standards are described. The GSMs, numbering plan, radio channel structure, mobility management, call routing and signaling,

Moe Rahnema

1993-01-01

21

Nerve cell damage in mammalian brain after exposure to microwaves from GSM mobile phones.  

PubMed Central

The possible risks of radio-frequency electromagnetic fields for the human body is a growing concern for our society. We have previously shown that weak pulsed microwaves give rise to a significant leakage of albumin through the blood-brain barrier. In this study we investigated whether a pathologic leakage across the blood-brain barrier might be combined with damage to the neurons. Three groups each of eight rats were exposed for 2 hr to Global System for Mobile Communications (GSM) mobile phone electromagnetic fields of different strengths. We found highly significant (p< 0.002) evidence for neuronal damage in the cortex, hippocampus, and basal ganglia in the brains of exposed rats. PMID:12782486

Salford, Leif G; Brun, Arne E; Eberhardt, Jacob L; Malmgren, Lars; Persson, Bertil R R

2003-01-01

22

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

PubMed

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. Bioelectromagnetics. 36:87-95, 2015. © 2015 Wiley Periodicals, Inc. PMID:25644316

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

2015-02-01

23

How to Turn a GSM SIM into a Web Server Projecting Mobile Trust onto the World Wide Web  

E-print Network

1 How to Turn a GSM SIM into a Web Server Projecting Mobile Trust onto the World Wide Web Scott.Posegga@Telekom.de Key words: Smart Cards, GSM SIMs, Web Servers, Security Infrastructure Abstract: We describe the WebSIM, an approach that integrates GSM SIMs into the Internet. The underlying idea is to implement a Web Server

Posegga, Joachim

24

Electromagnetic interference with infusion pumps from GSM mobile phones.  

PubMed

Electromagnetic interference with critical medical care devices has been reported by various groups. Previous studies have demonstrated that volumetric and syringe pumps are susceptible to false alarm buzzing and blocking when exposed to various electromagnetic sources. The risk of electromagnetic interference depends on several factors such as the phone-emitted power, distance, and carrier frequency. The aim of this study was to assess the risk of GSM phone-induced electromagnetic interference with volumetric and syringe pumps, at various distances and emitted powers. Malfunctions were observed in 6 out of 8 volumetric pumps and in 1 out of 4 syringe pumps exposed to mobile phones at their maximum output, at distances up to 30 cm. The maximum power that did not induce any malfunction at zero distance was 50 mW at 900 MHz and 2.5 mW at 1,800 MHz. In state-of-the-art pumps, the presence of moderate-good base station coverage would significantly reduce the risk of electromagnetic interference. PMID:16538140

Calcagnini, Giovanni; Floris, Matteo; Censi, Federica; Cianfanelli, Plinio; Scavino, Giovanni; Bartolini, Pietro

2006-04-01

25

Single-channel blind equalization for GSM cellular systems  

Microsoft Academic Search

This paper focuses on the study of blind equalization global system for mobile communications (GSM) systems using a single antenna. In order to utilize the well-known linear system model in conventional studies of blind equalization, an equivalent baseband quadrature amplitude modulation (QAM) approximation is used for the nonlinear GMSK signal in GSM systems. Since the GMSK signal in GSM has

Zhi Ding; Ge Li

1998-01-01

26

Transmitting patient and device data via GSM--central management for decentral mobile medical devices.  

PubMed

Equipping medical devices with long range telemetry opens completely new possibilities for emergency response, home care and remote diagnosis. Mobile communications nowadays seem to be a generally accepted part of our modern world, but bridging the gap between new (consumer-) technologies and medical devices still is a challenge today. Providing a telemetry link (GSM) is just the trivial part--ensuring security, reliability and service management are the more critical tasks that need to be addressed. Therefore, a complete system concept consists of an automatic fleet management (e.g. periodic device-initiated service calls) as well as customer relationship management (CRM), including technical service and a trouble-ticket system. PMID:12451860

Bachmor, T; Schöchlin, J; Bolz, A

2002-01-01

27

GSM enhanced full rate speech codec  

Microsoft Academic Search

This paper describes the GSM enhanced full rate (EFR) speech codec that has been standardised for the GSM mobile communication system. The GSM EFR codec has been jointly developed by Nokia and University of Sherbrooke. It provides speech quality at least equivalent to that of a wireline telephony reference (32 kbit\\/s ADPCM). The EFR codec uses 12.2 kbit\\/s for speech

K. Jarvinen; J. Vainio; P. Kapanen; T. Honkanen; P. Haavisto; R. Salami; C. Laflamme; J.-P. Adoul

1997-01-01

28

RF propagation simulator to predict location accuracy of GSM mobile phones for emergency applications  

NASA Astrophysics Data System (ADS)

Mobile location is one of the fastest growing areas for the development of new technologies, services and applications. This paper describes the channel models that were developed as a basis of discussion to assist the Technical Subcommittee T1P1.5 in its consideration of various mobile location technologies for emergency applications (1997 - 1998) for presentation to the U.S. Federal Communication Commission (FCC). It also presents the PCS 1900 extension to this model, which is based on the COST-231 extended Hata model and review of the original Okumura graphical interpretation of signal propagation characteristics in different environments. Based on a wide array of published (and non-publicly disclosed) empirical data, the signal propagation models described in this paper were all obtained by consensus of a group of inter-company participants in order to facilitate the direct comparison between simulations of different handset-based and network-based location methods prior to their standardization for emergency E-911 applications by the FCC. Since that time, this model has become a de-facto standard for assessing the positioning accuracy of different location technologies using GSM mobile terminals. In this paper, the radio environment is described to the level of detail that is necessary to replicate it in a software environment.

Green, Marilynn P.; Wang, S. S. Peter

2002-11-01

29

Effects of electromagnetic fields emitted by mobile phones (GSM 900 and WCDMA/UMTS) on the macrostructure of sleep.  

PubMed

In the present double-blind, randomized, sham-controlled cross-over study, possible effects of electromagnetic fields emitted by Global System for Mobile Communications (GSM) 900 and Wideband Code-Division Multiple Access (WCDMA)/Universal Mobile Telecommunications System (UMTS) cell-phones on the macrostructure of sleep were investigated in a laboratory environment. An adaptation night, which served as screening night for sleep disorders and as an adjustment night to the laboratory environment, was followed by 9 study nights (separated by a 2-week interval) in which subjects were exposed to three exposure conditions (sham, GSM 900 and WCDMA/UMTS). The sample comprised 30 healthy male subjects within the age range 18-30 years (mean ± standard deviation: 25.3 ± 2.6 years). A cell-phone usage at maximum radio frequency (RF) output power was simulated and the transmitted power was adjusted in order to approach, but not to exceed, the specific absorption rate (SAR) limits of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) guidelines for general public exposure (SAR(10g) = 2.0 W kg(-1)). In this study, possible effects of long-term (8 h) continuous RF exposure on the central nervous system were analysed during sleep, because sleep is a state in which many confounding intrinsic and extrinsic factors (e.g. motivation, personality, attitude) are eliminated or controlled. Thirteen of 177 variables characterizing the initiation and maintenance of sleep in the GSM 900 and three in the WCDMA exposure condition differed from the sham condition. The few significant results are not indicative of a negative impact on sleep architecture. From the present results there is no evidence for a sleep-disturbing effect of GSM 900 and WCDMA exposure. PMID:20561179

Danker-Hopfe, Heidi; Dorn, Hans; Bahr, Achim; Anderer, Peter; Sauter, Cornelia

2011-03-01

30

GSM mobile phone radiation suppresses brain glucose metabolism  

PubMed Central

We investigated the effects of mobile phone radiation on cerebral glucose metabolism using high-resolution positron emission tomography (PET) with the 18F-deoxyglucose (FDG) tracer. A long half-life (109?minutes) of the 18F isotope allowed a long, natural exposure condition outside the PET scanner. Thirteen young right-handed male subjects were exposed to a pulse-modulated 902.4?MHz Global System for Mobile Communications signal for 33?minutes, while performing a simple visual vigilance task. Temperature was also measured in the head region (forehead, eyes, cheeks, ear canals) during exposure. 18F-deoxyglucose PET images acquired after the exposure showed that relative cerebral metabolic rate of glucose was significantly reduced in the temporoparietal junction and anterior temporal lobe of the right hemisphere ipsilateral to the exposure. Temperature rise was also observed on the exposed side of the head, but the magnitude was very small. The exposure did not affect task performance (reaction time, error rate). Our results show that short-term mobile phone exposure can locally suppress brain energy metabolism in humans. PMID:21915135

Kwon, Myoung Soo; Vorobyev, Victor; Kännälä, Sami; Laine, Matti; Rinne, Juha O; Toivonen, Tommi; Johansson, Jarkko; Teräs, Mika; Lindholm, Harri; Alanko, Tommi; Hämäläinen, Heikki

2011-01-01

31

Mobile Station Positioning Using GSM Cellular Phone and Artificial Neural Networks  

Microsoft Academic Search

In this paper, we describe a novelapproach to mobile station positioning using a GSMmobile phone. The approach is based on the use of aninherent feature of the GSM cellular system (themobile phone continuously measures radio signalstrengths from a number of the nearest base stations(antennas)) and on the use of this information to estimatethe phone's location. The current values of the

Zoran Salcic; Edwin Chan

2000-01-01

32

GSM Security Using Identity-based Cryptography  

E-print Network

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.

Agarwal, Animesh; Das, Manik Lal

2009-01-01

33

Improvments in Railway Communication via GSM-R  

Microsoft Academic Search

In this paper we identify several shortcomings in GSM-R use for high-speed trains. Especially cell reselection and handover last too long. If they are combined with Group Receive Mode this causes additional problems. One single solution can help to cope with them. If handover and cell reselection are aided by location information they can be accelerated. Three strategies how to

Kira Kastell; Steffen Bug; Alexey Nazarov; Rolf Jakoby

2006-01-01

34

An Intelligent Location Management approaches in GSM Mobile Network  

E-print Network

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

Rao, N Mallikharjuna

2012-01-01

35

On the mechanisms of interference between mobile phones and pacemakers: parasitic demodulation of GSM signal by the sensing amplifier.  

PubMed

The aim of this study was to investigate the mechanisms by which the radiated radiofrequency (RF) GSM (global system for mobile communication) signal may affect pacemaker (PM) function. We measured the signal at the output of the sensing amplifier of PMs with various configurations of low-pass filters. We used three versions of the same PM model: one with a block capacitor which short circuits high-frequency signals; one with a ceramic feedthrough capacitor, a hermetically sealed mechanism connecting the internal electronics to the external connection block, and one with both. The PMs had been modified to have an electrical shielded connection to the output of the sensing amplifier. For each PM, the output of the sensing amplifier was monitored under exposure to modulated and non-modulated RF signals, and to GSM signals (900 and 1800 MHz). Non-modulated RF signals did not alter the response of the PM sensing amplifier. Modulated RF signals showed that the block capacitor did not succeed in short circuiting the RF signal, which is somehow demodulated by the PM internal non-linear circuit elements. Such a demodulation phenomenon poses a critical problem because digital cellular phones use extremely low-frequency modulation (as low as 2 Hz). which can be mistaken for normal heartbeat. PMID:12817944

Barbaro, V; Bartolini, P; Calcagnini, G; Censi, F; Beard, B; Ruggera, P; Witters, D

2003-06-01

36

Short GSM mobile phone exposure does not alter human auditory brainstem response  

PubMed Central

Background There are about 1.6 billion GSM cellular phones in use throughout the world today. Numerous papers have reported various biological effects in humans exposed to electromagnetic fields emitted by mobile phones. The aim of the present study was to advance our understanding of potential adverse effects of the GSM mobile phones on the human hearing system. Methods Auditory Brainstem Response (ABR) was recorded with three non-polarizing Ag-AgCl scalp electrodes in thirty young and healthy volunteers (age 18–26 years) with normal hearing. ABR data were collected before, and immediately after a 10 minute exposure to 900 MHz pulsed electromagnetic field (EMF) emitted by a commercial Nokia 6310 mobile phone. Fifteen subjects were exposed to genuine EMF and fifteen to sham EMF in a double blind and counterbalanced order. Possible effects of irradiation was analyzed by comparing the latency of ABR waves I, III and V before and after genuine/sham EMF exposure. Results Paired sample t-test was conducted for statistical analysis. Results revealed no significant differences in the latency of ABR waves I, III and V before and after 10 minutes of genuine/sham EMF exposure. Conclusion The present results suggest that, in our experimental conditions, a single 10 minute exposure of 900 MHz EMF emitted by a commercial mobile phone does not produce measurable immediate effects in the latency of auditory brainstem waves I, III and V. PMID:17997856

Stefanics, Gábor; Kellényi, Lóránd; Molnár, Ferenc; Kubinyi, Györgyi; Thuróczy, György; Hernádi, István

2007-01-01

37

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

PubMed

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

Mortazavi, Smj; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, Ar

2014-09-01

38

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

PubMed Central

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

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

2014-01-01

39

Life Cycle Assessment of the Mobile Communication System UMTS: Towards Eco-efficient Systems (12 pp)  

Microsoft Academic Search

Goal, Scope and Background   Goal of this study is an evaluation of the environmental sustainability of the UMTS mobile communication system in Switzerland\\u000a by means of a Life Cycle Assessment (LCA). A baseline environmental impact profile across the full life cycle of the UMTS\\u000a (Universal Mobile Telecommunication System) and its predecessor, the GSM (Global System for Mobile Communication) is presented.

Mireille Faist Emmenegger; Rolf Frischknecht; Markus Stutz; Michael Guggisberg; Res Witschi; Tim Otto

2006-01-01

40

Mobile satellite communications  

Microsoft Academic Search

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

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

1994-01-01

41

General packet radio service in GSM  

Microsoft Academic Search

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

Jain Cai; David J. Goodman

1997-01-01

42

Design of fault monitoring alarm system for networks based on GSM SMS  

Microsoft Academic Search

The system is used as detecting server performance in a computer networks. Based on SNMP agreement, it implements data acquisition, processing and chart show using APACHE + PHP + MYSQL. Through serial communication between the GSM module and VB, the GSM SMS including networks facult information is sent to defined mobile and thus build a better fault monitoring alarm system

F.-S. Bai; Y.-L. Liu

2010-01-01

43

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

E-print Network

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

Paris-Sud XI, Université de

44

Mobile Communications May 30, 2013  

E-print Network

Mobile Communications Program May 30, 2013 #12;Overview Background Financial Aspects Operational plans include mobile-mobile, nights & weekends Smartphones ­ 400 minute plan, includes unlimited data.98/month Unlimited text messaging can be added for $12/month Unlimited data for mobile broadband card

45

Acquisition of frequency synchronization for GSM and its evolution systems  

Microsoft Academic Search

In global system for mobile communication (GSM) and its evolution systems (such as general packet radio service, GPRS, and highspeed circuit switched data, HCSD), the cell related parameters are broadcast on a broadcast control channel (BCCH) to facilitate the mobile handsets in the area of coverage to acquire the frequency and timing synchronization as well as to obtain the cell

2000-01-01

46

Advanced Communications Technology: Mobile Communications Requirements Report  

NASA Astrophysics Data System (ADS)

The Coast Guard's mobile communications requirements will outstrip existing system capabilities, available capacity, and affordability by the late 1990s. This will require changes in the mix of mobile communications equipment and services used by operational units. New commercial mobile satellite services are available now, with many others arriving on the market between 1998 and 2003. These new services present unique opportunities to satisfy mission requirements, reduce investment in communications infrastructure, and realize more costeffective communications services. The Coast Guard Research and Development Center (R&DC) has undertaken an effort to identify and evaluate current and emerging satellite services that may be used to satisfy Coast Guard mobile communications requirements. As part of this effort, Anteon Corporation has been tasked by R&DC to collect the mobile communications functional requirements that have been identified by program managers. Anteon analysts have reviewed the Government Furnished Information (GFI) and researched other related documentation to identify and collect the requirements that may be used to describe the needed operating environment. Anteon analysts assessed the functional requirements to develop system requirements that describe the features that a communications system must provide to support the functional requirements. This report presents the current and projected Coast Guard mobile communications system requirements.

1998-05-01

47

Trends in mobile satellite communication  

Microsoft Academic Search

Ever since the U.S. Federal Communication Commission opened the discussion on spectrum usage for personal handheld communication, the community of satellite manufacturers has been searching for an economically viable and technically feasible satellite mobile communication system. Hughes Aircraft Company and others have joined in providing proposals for such systems, ranging from low to medium to geosynchronous orbits. These proposals make

Klaus G. Johannsen; Mike W. Bowles; Samuel Milliken; Alan R. Cherrette; Gregory C. Busche

1993-01-01

48

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

NASA Astrophysics Data System (ADS)

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.

Tafazolli, R.; Evans, B. G.

49

Trust and Security Realization for Mobile Users in GSM Cellular Networks  

Microsoft Academic Search

In recent past SMS (Short Message Service) has become very popular data bearer in GSM networks. SMS, inherently being a messaging protocol, has always been point-to-point and in plaintext. For m-commerce transactions, SMS will be routed through public networks and some application servers of the merchant. Also, to protect itself against unknown roaming environments, SMS needs peer-to-peer object level security

Jesudoss Venkatraman; Vijay V. Raghavan; Debabrata Das; Asoke K. Talukder

2004-01-01

50

Telemedicine by mobile communication  

Microsoft Academic Search

We have proposed some techniques for mobile telemedicine and have verified their practical feasibility in experiments. This article presents technical considerations required to realize a practical mobile telemedicine system, techniques developed for multiple medical data transmission, and the satisfactory results of their applications to telemedicine in moving vehicles

Koichi Shimizu

1999-01-01

51

Comparison of cytotoxic and genotoxic effects of plutonium-239 alpha particles and mobile phone GSM 900 radiation in the Allium cepa test.  

PubMed

The goal of this study was to compare the cytotoxic and genotoxic effects of plutonium-239 alpha particles and GSM 900 modulated mobile phone (model Sony Ericsson K550i) radiation in the Allium cepa test. Three groups of bulbs were exposed to mobile phone radiation during 0 (sham), 3 and 9h. A positive control group was treated during 20min with plutonium-239 alpha-radiation. Mitotic abnormalities, chromosome aberrations, micronuclei and mitotic index were analyzed. Exposure to alpha-radiation from plutonium-239 and exposure to modulated radiation from mobile phone during 3 and 9h significantly increased the mitotic index. GSM 900 mobile phone radiation as well as alpha-radiation from plutonium-239 induced both clastogenic and aneugenic effects. However, the aneugenic activity of mobile phone radiation was more pronounced. After 9h of exposure to mobile phone radiation, polyploid cells, three-groups metaphases, amitoses and some unspecified abnormalities were detected, which were not registered in the other experimental groups. Importantly, GSM 900 mobile phone radiation increased the mitotic index, the frequency of mitotic and chromosome abnormalities, and the micronucleus frequency in a time-dependent manner. Due to its sensitivity, the A. cepa test can be recommended as a useful cytogenetic assay to assess cytotoxic and genotoxic effects of radiofrequency electromagnetic fields. PMID:23059817

Pesnya, Dmitry S; Romanovsky, Anton V

2013-01-20

52

Enhancing ecommerce security using GSM authentication  

E-print Network

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

Dent, Alexander W.

53

Secure Mobile IP Communication  

E-print Network

Universität Bern Vorgelegt von: Marc Danzeisen Leiter der Arbeit: Prof. Dr. Torsten Braun Forschungsgruppe networking, Sun Microsystems, Inc. 29 5.4 Comparison of the different concepts 31 6 SECMIP: A SECURED MOBILE

Braun, Torsten

54

Interference diversity gain in frequency hopping GSM  

Microsoft Academic Search

Wideband random frequency hopping is one of the key properties of GSM in an evolution towards PCS (personal communication services). Random frequency hopping introduces diversity on the transmission link, which improves the performance. In this paper, the impact of interference diversity in GSM is analyzed by means of bit level simulations of the GSM full rate speech channel. The analysis

H. Olofsson; J. Naslund; J. Skold

1995-01-01

55

Internal Patch Antenna With a Thin Air-Layer Substrate for GSM\\/DCS Operation in a PDA Phone  

Microsoft Academic Search

A thin dual-band internal patch antenna for Global System for Mobile Communication, 890-960 MHz\\/Digital Communication System, 1710-1880 MHz (GSM\\/DCS) operation in a Personal Digital Assistant (PDA) phone is presented. The antenna can generate two wide resonant modes for GSM (890-960 MHz) and DCS (1710-1880 MHz) operation, yet it requires an air-layer substrate of thickness 4 mm only, which is among

Kin-Lu Wong; Yuan-Chih Lin

2007-01-01

56

Throughput and buffer analysis for GSM General Packet Radio Service (GPRS)  

Microsoft Academic Search

The Global System for Mobile Communications (GSM) Phase 2+ standard specifies a new type of packet data service called General Packet Radio Service (GPRS). GPRS allows the dynamic allocation of bandwidth resources. Wireless channels are allocated to a mobile terminal based on its traffic demands. This results in better resource utilization compared to the circuit-based data services. In general, packet-based

Joseph Ho; Yixin Zhu; S. Madhavapeddy

1999-01-01

57

Trends in mobile satellite communication  

NASA Astrophysics Data System (ADS)

Ever since the U.S. Federal Communication Commission opened the discussion on spectrum usage for personal handheld communication, the community of satellite manufacturers has been searching for an economically viable and technically feasible satellite mobile communication system. Hughes Aircraft Company and others have joined in providing proposals for such systems, ranging from low to medium to geosynchronous orbits. These proposals make it clear that the trend in mobile satellite communication is toward more sophisticated satellites with a large number of spot beams and onboard processing, providing worldwide interconnectivity. Recent Hughes studies indicate that from a cost standpoint the geosynchronous satellite (GEOS) is most economical, followed by the medium earth orbit satellite (MEOS) and then by the low earth orbit satellite (LEOS). From a system performance standpoint, this evaluation may be in reverse order, depending on how the public will react to speech delay and collision. This paper discusses the trends and various mobile satellite constellations in satellite communication under investigation. It considers the effect of orbital altitude and modulation/multiple access on the link and spacecraft design.

Johannsen, Klaus G.; Bowles, Mike W.; Milliken, Samuel; Cherrette, Alan R.; Busche, Gregory C.

58

Trends in mobile satellite communication  

NASA Technical Reports Server (NTRS)

Ever since the U.S. Federal Communication Commission opened the discussion on spectrum usage for personal handheld communication, the community of satellite manufacturers has been searching for an economically viable and technically feasible satellite mobile communication system. Hughes Aircraft Company and others have joined in providing proposals for such systems, ranging from low to medium to geosynchronous orbits. These proposals make it clear that the trend in mobile satellite communication is toward more sophisticated satellites with a large number of spot beams and onboard processing, providing worldwide interconnectivity. Recent Hughes studies indicate that from a cost standpoint the geosynchronous satellite (GEOS) is most economical, followed by the medium earth orbit satellite (MEOS) and then by the low earth orbit satellite (LEOS). From a system performance standpoint, this evaluation may be in reverse order, depending on how the public will react to speech delay and collision. This paper discusses the trends and various mobile satellite constellations in satellite communication under investigation. It considers the effect of orbital altitude and modulation/multiple access on the link and spacecraft design.

Johannsen, Klaus G.; Bowles, Mike W.; Milliken, Samuel; Cherrette, Alan R.; Busche, Gregory C.

1993-01-01

59

Mobile Communication Device Allowance Authorization Form Revised: April 2011 MOBILE COMMUNICATION DEVICE ALLOWANCE AUTHORIZATION FORM  

E-print Network

Mobile Communication Device Allowance Authorization Form Revised: April 2011 MOBILE COMMUNICATION list your CURRENT PLAN features: Mobile service provider Name: ________ Monthly Charge: $ Device.edu/policy/itc/FINAL%20Policy%20on%20Mobile%20Comm%20Devices.htm I have read the Mobile Communication Devices Policy

Dyer, Bill

60

A GSM\\/EDGE\\/WCDMA modulator with on-chip D\\/A converter for base stations  

Microsoft Academic Search

A global system for mobile communication (GSM)\\/enhanced data rates for GSM evolution (EDGE)\\/wideband code division multiple access (WCDMA) modulator with a 14-bit on-chip digital-to-analog (D\\/A) converter is presented. The modulator consists of several digital signal processing building blocks, including a programmable pulse shaping filter, interpolation filters, resampler, co-ordinate rotation digital computer (CORDIC) rotator, programmable output power level controller and ramping

Jouko Vankka; Jaakko Ketola; Johan Sommarek; Olli Väänänen; Marko Kosunen; Kari A. I. Halonen

2002-01-01

61

Communications Systems for Mobile Robotics  

SciTech Connect

Performance Confirmation is the activity by which the Yucca Mountain Project confirms that the engineered and natural containment barriers of this national nuclear waste repository are performing as predicted, so that an eventual decision to close the repository can be made. This activity involves systems that must be inspected and, in some cases, serviced by mobile robots. This paper discusses systems for underground mobile robot communications, including requirements, environments, options, issues, and down-select criteria. We reviewed a variety of systems, including Slotted Waveguide, Powerline Carrier, Leaky Feeder, Photonic Bandgap Fiber, Free-Space Optics, Millimeter Waves, Terahertz Systems, and RF Systems (including IEEE 802.11 a,b, and g, and Ultra-Wideband radio).

Futterman, J A; Pao, H

2003-12-08

62

A review of mobile satellite communication systems  

NASA Astrophysics Data System (ADS)

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.

Kondo, Kimio

1990-03-01

63

Mobile Communication Security Controllers An Evaluation Paper  

E-print Network

wireless and fixed communications is increasingly blurred and if we consider modern Near Field Communication (NFC)2 we will see mobile phones acting as credit cards, train tickets or smart poster readers

Mayes, Keith

64

Method for Evaluation of Outage Probability on Random Access Channel in Mobile Communication Systems  

NASA Astrophysics Data System (ADS)

In order to access the cell in all mobile communication technologies a so called random-access procedure is used. For example in GSM this is represented by sending the CHANNEL REQUEST message from Mobile Station (MS) to Base Transceiver Station (BTS) which is consequently forwarded as an CHANNEL REQUIRED message to the Base Station Controller (BSC). If the BTS decodes some noise on the Random Access Channel (RACH) as random access by mistake (so- called ‘phantom RACH') then it is a question of pure coincidence which èstablishment cause’ the BTS thinks to have recognized. A typical invalid channel access request or phantom RACH is characterized by an IMMEDIATE ASSIGNMENT procedure (assignment of an SDCCH or TCH) which is not followed by sending an ESTABLISH INDICATION from MS to BTS. In this paper a mathematical model for evaluation of the Power RACH Busy Threshold (RACHBT) in order to guaranty in advance determined outage probability on RACH is described and discussed as well. It focuses on Global System for Mobile Communications (GSM) however the obtained results can be generalized on remaining mobile technologies (ie WCDMA and LTE).

Kollár, Martin

2012-05-01

65

Satellite communication and navigation for mobile users  

NASA Technical Reports Server (NTRS)

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.

Bernstein, S. L.

1972-01-01

66

Evaluation of a MAC protocol proposed for a general packet radio service in GSM  

Microsoft Academic Search

One major issue of the phase 2+ development of the pan-European Global System for Mobile communications (GSM) is to specify a general packet radio service (GPRS). Such a service is necessary to be able to fulfil the increased user requirements for reasonable data services. In this paper, an overview about the overall GPRS concept, its architecture and service characteristics is

G. Brasche

1996-01-01

67

Experiment In Aeronautical-Mobile/Satellite Communication  

NASA Technical Reports Server (NTRS)

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).

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

1992-01-01

68

Reinventing Mobile Community Computing and Communication  

E-print Network

Networking Apps (SNAPPs) In our vision, mobile devices should become effective human assistants, reactingReinventing Mobile Community Computing and Communication (Position Paper) Yann Busnel, Nuno Cruz, smartphones and mobile applications spread like wildfire and dramatically improved aspects of our professional

Paris-Sud XI, Université de

69

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

PubMed Central

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 Ñora (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

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

2013-01-01

70

Effective Protocols for Mobile Communications and Networking  

SciTech Connect

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.

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

1998-12-01

71

Enhancing e-commerce security using GSM authentication  

E-print Network

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

Mitchell, Chris

72

Analysis of the General Packet Radio Service (GPRS) of GSM as access to the Internet  

Microsoft Academic Search

The General Packet Radio Service (GPRS) of the Global System for Mobile Communications (GSM) is designed for packet switched data transmission and is a means of mobile access to packet data networks, e.g. the Internet. Packet switched transmission is inherently better suited for bursty traffic as it is generated by typical Internet applications-primarily WWW, FTP and e-mail. A simulator is

Simon Hoff; Michael Meyer; Joachim Sachs

1998-01-01

73

Mobile image communication using JPEG2000  

E-print Network

Mobile image communication using JPEG2000 René Rosenbaum, Heidrun Schumann University of Rostock pipeline to a single task-aligned system. To achieve this, the modern imaging standard JPEG2000 serves using JPEG2000. 1 INTRODUCTION The enthusiasm for mobile computing is still unbroken. With the ability

Rosenbaum, Rene

74

USDA Forest Service mobile satellite communications applications  

NASA Technical Reports Server (NTRS)

The airborne IR signal processing system being developed will require the use of mobile satellite communications to achieve its full capability and improvement in delivery timeliness of processed IR data to the Fire Staff. There are numerous other beneficial uses, both during wildland fire management operations or in daily routine tasks, which will also benefit from the availability of reliable communications from remote areas.

Warren, John R.

1990-01-01

75

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

E-print Network

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.

Elouafiq, Ali

2012-01-01

76

Interference rejection combining for GSM  

Microsoft Academic Search

Digital cellular communication systems in urban areas are today beginning to be limited in performance by interference. To further increase the capacity in these areas, more advanced detection schemes could be used. We study how the performance of the MLSE equalizer can be improved by utilizing interference suppression. Simulation results for a GSM system under realistic conditions are presented

Jonas Karlsson; J. Heinegard

1996-01-01

77

Analysis of multi-slot MAC protocols proposed for the GSM phase 2+ general packet radio service  

Microsoft Academic Search

In 1994 the European Telecommunications Standards institute (ETSI) started work on the specification of a general packet radio service (GPRS) as part of the Global System for Mobile communications (GSM) Phase 2+ development. By the end of 1997 standardization will presumably come to an end and the first introduction of GPRS will follow soon. On the basis of GPRS a

G. Brasche; B. Walke

1997-01-01

78

Acute effects of electromagnetic fields emitted by GSM mobile phones on subjective well-being and physiological reactions: a meta-analysis.  

PubMed

The potential effects of radiofrequency electromagnetic fields (RF-EMF) emitted by GSM mobile phones on subjective symptoms, well-being and physiological parameters have been investigated in many studies. However, the results have been ambiguous. The current meta-analysis aims to clarify whether RF-EMF have an influence on well-being in self-reported sensitive persons, as well as in non-sensitive people. A literature search revealed 17 studies including 1174 participants. The single effects for various subjective and objective outcomes were meta-analytically combined to yield a single population parameter. Dependant variables were subjective (e.g. headaches) and objective parameters (e.g. heart rate variability) of well-being. The results show no significant impact of short-term RF-EMF exposure on any parameter. Future research should focus on the possible effects of long-term exposure. PMID:22421088

Augner, Christoph; Gnambs, Timo; Winker, Robert; Barth, Alfred

2012-05-01

79

Understanding GPRS: the GSM packet radio service  

Microsoft Academic Search

The General Packet Radio Service (GPRS), a data extension of the mobile telephony standard GSM, is emerging as the first true packet-switched architecture to allow mobile subscribers to benefit from high-speed transmission rates and run data applications from their mobile terminals. A high-level description of the GPRS system is given with emphasis on services and architectural aspects.

Brahim Ghribi; Luigi Logrippo

2000-01-01

80

Mobile satellite communications in the Forest Service  

NASA Technical Reports Server (NTRS)

There are usually some places within a forest that do not have adequate communication coverage due to line-of-sight or other reasons. These areas are generally known by the foresters and radio technicians and allowances are made for that when working or traveling in those areas. However, when wildfire or other emergencies occur, communications are vital because wildfires can require hundreds of firefighters and cover thousands of acres. During these emergency operations, the existing communications are not adequate and complete radio systems are moved into the area for the conduct of fire communications. Incident command posts (ICPs) and fire camps are set up in remote locations and there is constant need for communications in the fire area and to agency headquarters and dispatch offices. Mobile satellite communications would be an ideal supplement to the Forest Service's current communications system in aiding forest fire control activities.

Warren, John R.

1988-01-01

81

Modeling and Analysis of Mobility Management in Mobile Communication Networks  

PubMed Central

Many strategies have been proposed to reduce the mobility management cost in mobile communication networks. This paper studies the zone-based registration methods that have been adopted by most mobile communication networks. We focus on two special zone-based registration methods, called two-zone registration (2Z) and two-zone registration with implicit registration by outgoing calls (2Zi). We provide a new mathematical model to analyze the exact performance of 2Z and 2Zi. We also present various numerical results, to compare the performance of 2Zi with those of 2Z and one-zone registration (1Z), and show that 2Zi is superior to 2Z as well as 1Z in most cases. PMID:24883368

Yoon, Ji Hyun; Kim, Chesoong

2014-01-01

82

Microstrip monopulse antenna for land mobile communications  

NASA Technical Reports Server (NTRS)

Low cost is one of the main requirements in a communication system suitable for mass production, as it is the case for satellite land mobile communications. Microstrip technology fulfills this requirement which must be supported by a low cost tracking system design. The tradeoff led us to a prototype antenna composed of microstrip patches based on electromechanical closed-loop principle; the design and the results obtained are described.

Garcia, Q.; Martin, C.; Delvalle, J. C.; Jongejans, A.; Rinous, P.; Travers, M. N.

1993-01-01

83

Electromagnetic field pattern in the environment of GSM base stations.  

PubMed

Three mobile phone systems are used in Poland: analog, operated at the 450 MHz frequency range, and two digital systems operated at 900 MHz and 1800 MHz. The GSM--Global System for Mobile Communication meets all relevant requirements, and it is most widely used throughout the world. According to the mobile phone concept, the whole communication area is divided into sub-areas (cells) where base stations are located. The base stations are provided with the transmitter units mounted on free-standing masts, high chimneys and building roofs, including those of the residential buildings. The transmitter antennas of the base stations constitute a source of 935-960 EMF radiation. This work analyses the essential characteristics of the base station antennas from the point of view of radiation intensity. The analysis is based on the results of EMF measurements performed by experts of two relevant research institutes. For inaccessible antennas, the measurements were performed at the accredited laboratory. PMID:10360084

Anio?czyk, H

1999-01-01

84

Solutions to the GSM Security Weaknesses  

E-print Network

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.

Toorani, Mohsen; 10.1109/NGMAST.2008.88

2010-01-01

85

TACNET: Mobile ad hoc Secure Communications Network  

Microsoft Academic Search

On the road and during tactical maneuvers, the Blue Force must maintain situational awareness to effectively react and respond. The Tactical Network, or TacNet, is a mobile ad hoc communications network developed by Sandia National Laboratories to provide Blue Force personnel with secure access to critical data, such as real-time maps of resource positions. During development of the system, the

L. E. Riblett; J. M. Wiseman

2007-01-01

86

1. Final Title SECURITY of MOBILE COMMUNICATIONS  

E-print Network

limitations; c) the user requirements; d) the contents of provided services; and e) the evolution of hacking of security attacks and hacking techniques; 3) discussing security policies and security practices to help for hacking systems via mobile communications. Threats and risk analysis are discussed in this part, along

87

Multidimensional Human Dynamics in Mobile Phone Communications  

PubMed Central

In today's technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages). Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today's information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process. PMID:25068479

Quadri, Christian; Zignani, Matteo; Capra, Lorenzo; Gaito, Sabrina; Rossi, Gian Paolo

2014-01-01

88

A 2.7-4.5 V single chip GSM transceiver RF integrated circuit  

Microsoft Academic Search

This paper describes the design and implementation of a single-chip GSM (Global System for Mobile communications) transceiver RF integrated circuit. The chip includes the RF-to-baseband and baseband-to-RF (receive and transmit) functions, two fixed frequency PLL's, and a programmable frequency agile UHF synthesizer. It is implemented In a 1.5 ?m silicon bipolar process with 12 GHz NPN's and 110 MHz lateral

Trudy D. Stetzler; Irving G. Post; Joseph H. Havens; Mikio Koyama

1995-01-01

89

Application of Mobile Router to Military Communications  

NASA Technical Reports Server (NTRS)

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 that resides in a network router. A Mobile-Router allows entire networks to roam while maintaining connectivity to the Internet. This router code is pertinent to a myriad of applications for both the government and commercial sectors. This technology will be applied to the wireless battlefield. NASA and the Department of Defense will utilize this technology for near-planetary observation and sensing spacecraft. It is the enabling technology for communication via the Internet or Intranets to aircraft. Information such as weather, air traffic control, voice and video can be easily and inexpensively transmitted to the aircraft using Internet protocols. The mobile router can be incorporated into emergency vehicles particularly ambulances and life-flight aircraft to provide real-time connectivity back to the hospital and healthcare experts. Commercial applications include entertainment services, IP telephone, and Internet connectivity for cruise ships, commercial shipping, tour busses, aircraft, and eventually cars. This paper will briefly describe the mobile router operation. An upcoming wide area network field test with application to US Coast Guard communications will be described. The paper will also highlight military and government networks that will benefit from the deployment of mobile router and the associated applications.

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

2002-01-01

90

Antenna technology for advanced mobile communication systems  

NASA Technical Reports Server (NTRS)

The onboard antenna front end is the key subsystem conditioning configuration and performance of mobile communication satellites. The objectives of this paper are to demonstrate this key role and to review L-band satellite antenna technology for earth coverage and regional applications. Multibeam arrays are first discussed, then unfurlable and inflatable reflector antennas are described. These technologies are now qualified in Europe for future mobile systems, for which the optimum choice of antenna technology has been found to be the key to efficient use of spectrum and power resources.

Rammos, Emmanuel; Roederer, Antoine; Rogard, Roger

1988-01-01

91

Aspects of introducing EDGE in existing GSM networks  

Microsoft Academic Search

The use of higher level modulation to provide Enhanced Data rates for Global\\/GSM Evolution (EDGE) is currently being standardized for GSM by the European Telecommunications Standards Institute (ETSI), and is also adopted for D-AMPS (IS-136) evolution by the Universal Wireless Communications Consortium (UWCC). This paper discusses a number of important aspects of introducing EDGE in an existing GSM system, such

Hikan Olofsson; Anders Furuskar

1998-01-01

92

GSM-moduuli osana ohjausjärjestelmää.  

E-print Network

??Tässä opinnäytetyössä käsitellään sulautettuja järjestelmiä, GSM-verkon rakennetta ja tutkitaan GSM-päätelaitteen soveltuvuutta sulautetun järjestelmän M2Mohjaukseen. Lisäksi esitellään järjestelmäesimerkissä käytettävä GSM-moduuli ja sen käyttöönotto. Työ sisältää myös… (more)

Mönkkönen, Arvi

2007-01-01

93

GSM-moduuli sulautetussa järjestelmässä.  

E-print Network

??Tässä opinnäytetyössä tutustuttiin GSM-moduulin ohjaukseen ja käyttöön sulautetussa järjestelmässä. Työssä käytettiin apuna Olimexin AVR-GSM-kehitysalustaa. Kehitysalustan tärkeimmät komponentit ovat ATMega32-mikrokontrolleri sekä Simcomin SIM300D GSM-moduuli. Työssä esitellään… (more)

Rantanen, Timo

2011-01-01

94

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

95

Enhanced emergency communication using mobile sensing and MANET  

Microsoft Academic Search

Emergency response services are often delayed due to the destruction or non-availability of the communication network. This research work proposes Mobile Adhoc NETwork (MANET) architecture integrated with mobile sensing concepts, for reviving the communication network in disaster hit areas. Mobile sensing in emergency scenarios can very well address issues like victim localization etc. and offer help in providing specific information

Maneesha V. Ramesh; Anoop Jacob; Aryadevi R. Devidas

2012-01-01

96

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

E-print Network

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

Gesbert, David

97

Dynamic decision engine for unified communication  

Microsoft Academic Search

Enterprises nowadays are approaching towards an all IP paradigm by subscribing to different access technology links from several service providers for reliability and redundancy while providing good Quality of Service (QoS). Global System for Mobile Communications (GSM) to Voice over IP (GSM-2-VoIP) convergence and vice-versa is a step forward towards this unification goal. It requires dynamic routing between IP, digital,

Sajjad Ali Mushtaq; Annie Gravey; Christophe Lohr

2011-01-01

98

Advanced communications payload for mobile applications  

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

99

Lens Antenna For Mobile/Satellite Communication  

NASA Technical Reports Server (NTRS)

Flat, compact antenna made of stripline elements aimed at fixed elevation angle but steered electronically in azimuth. Design simplified by maintaining fixed elevation and relying on width of beam to cover desired elevation range. Need for phase shifter at each radiating element eliminated by arranging elements in circles and feeding through stripline disks called "R-KR lenses". Used in Mobile/Satellite Service, antenna mounted on top of vehicle on Earth and used to keep transmitted and received antenna beams aimed approximately toward communication satellite.

Bodnar, D. G.; Rainer, B. K.

1988-01-01

100

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

PubMed Central

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

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

101

Personal Mobility in the ICEBERG Integrated Communication Network  

E-print Network

Personal Mobility in the ICEBERG Integrated Communication Network Bhaskaran Raman bhaskar communication services in a personalized, unified, and clean fashion across these devices. The Iceberg Project as defined by Iceberg are much richer than the corresponding concepts in traditional telephony

Raman, Bhaskaran

102

Consensus in networks of mobile communicating agents  

NASA Astrophysics Data System (ADS)

Populations of mobile and communicating agents describe a vast array of technological and natural systems, ranging from sensor networks to animal groups. Here, we investigate how a group-level agreement may emerge in the continuously evolving network defined by the local interactions of the moving individuals. We adopt a general scheme of motion in two dimensions and we let the individuals interact through the minimal naming game, a prototypical scheme to investigate social consensus. We distinguish different regimes of convergence determined by the emission range of the agents and by their mobility, and we identify the corresponding scaling behaviors of the consensus time. In the same way, we rationalize also the behavior of the maximum memory used during the convergence process, which determines the minimum cognitive/storage capacity needed by the individuals. Overall, we believe that the simple and general model presented in this paper can represent a helpful reference for a better understanding of the behavior of populations of mobile agents.

Baronchelli, Andrea; Díaz-Guilera, Albert

2012-01-01

103

Cryptanalysis and improvement of quantum secure communication network protocol with entangled photons for mobile communications  

NASA Astrophysics Data System (ADS)

Recently, a communication protocol called controlled bidirectional quantum secret direct communication for mobile networks was proposed by Chou et al (2014 Mobile Netw. Appl. 19 121). We study the security of the proposed communication protocol and find that it is not secure. The controller, Telecom Company, may eavesdrop secret messages from mobile devices without being detected. Finally, we give a possible improvement of the communication protocol.

Gao, Gan

2014-12-01

104

Vertailussa VoIP- ja GSM- järjestelmä.  

E-print Network

??GSM on maailman laajuisesti käytetty matkapuhelinjärjestelmä. Suomessa ensimmäinen GSM-toimilupa myönnettin Radiolinjalle vuonna 1990. GSM matkapuhelinjärjestelmä on lisännyt suosiotaan ja järjestelmä on hyvin pitkälle syrjäyttänyt perinteiset… (more)

Kopsala, Laura

2013-01-01

105

An HTS transceiver for third generation mobile communications  

Microsoft Academic Search

Future third-generation mobile communication systems will require improved sensitivity and selectivity to support the growth in multi-media services, increased coverage, longer talk time and larger numbers of subscribers. The paper describes a transceiver for use in mobile and personal communications base transceiver stations (BTS). Key components of the transceiver are fabricated using thin film high temperature superconductor technologies to achieve,

R. B. Greed; D. C. Voyce; D. Jedamzik; J. S. Hong; M. J. Lancaster; M. Reppel; H. J. Chaloupka; J. C. Mage; B. Marcilhac; R. Mistry; H. U. Hafner; G. Auger; W. Rebernak

1999-01-01

106

Accurate GSM Indoor Localization  

Microsoft Academic Search

Accurate indoor localization has long been an objective of the ubiquitous computing research community, and numerous indoor lo- calization solutions based on 802.11, Bluetooth, ultrasound and infrared technologies have been proposed. This paper presents the first accurate GSM indoor localization system that achieves median accuracy of 5 me- ters in large multi-floor buildings. The key idea that makes accurate GSM-based

Veljo Otsason; Alex Varshavsky; Anthony Lamarca; Eyal De Lara

2005-01-01

107

SAW based systems for mobile communications satellites  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

108

Land vehicle antennas for satellite mobile communications  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

109

A secure GSM-based electronic Murabaha transaction Mansour A. Al-Meaither and Chris J. Mitchell  

E-print Network

A secure GSM-based electronic Murabaha transaction Mansour A. Al-Meaither and Chris J. Mitchell a combination of the Internet, a GSM mobile device, and a hash-chain scheme related to S/KEY. After introducing the notion of Murabaha sale, we outline the GSM security model and the S/KEY scheme. Security requirements

Mitchell, Chris

110

Personal Mobility in the ICEBERG Integrated Communication Network  

E-print Network

Personal Mobility in the ICEBERG Integrated Communication Network Bhaskaran Raman Randy H. Katz in the ICEBERG Integrated Communication Network Bhaskaran Raman Randy H. Katz Anthony D. Joseph fbhaskar communication services in a personalized, unified, and clean fashion across these devices. The Iceberg Project

Joseph, Anthony D.

111

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

Julien INC2004INC2004 Seamless Communications for Mobile Emergency ServicesSeamless Communications for Mobile Emergency Services Seamless Communications for MobileSeamless Communications for Mobile Emergency ServicesEmergency2004 Seamless Communications for Mobile Emergency ServicesSeamless Communications for Mobile Emergency

Abu-Rgheff, Mosa Ali

112

Evaluation of a proposed handover algorithm for the GSM cellular system  

Microsoft Academic Search

In the future pan-European cellular mobile telephone system of the `Groupe Speciale Mobile (GSM)' of CEPT, the decision whether a handover shall happen can be based on a set of variables whose values are measured in the system. Some performance measures for handover algorithms are reported, and a simulation tool for the evaluation of a proposed GSM handover algorithm is

W. R. Mande

1990-01-01

113

A Novel Model for Optimized GSM Network Design  

E-print Network

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.

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

2009-01-01

114

Multiuser acoustic communications with mobile users.  

PubMed

A multiuser receiver is developed that is capable of separating receptions from independent, mobile users whose transmissions overlap in both time and frequency. With respect to any one user's Doppler corrected signal, the other communication signals appear as multiple-access interference distributed across the Doppler dimension. A previously developed receiver composed of an adaptive time-reversal processor embedded within a successive interference cancellation framework is limited to stationary users. This paper extends the receiver to properly remove the interference from moving sources by modeling the effects of Doppler through the interference cancellation receiver. The combined receiver has the ability to remove interference in both the temporal and spatial domains, and this property is shown to be preserved even when users are in motion. When applied to data collected during a recent shallow water experiment (KAM11), the receiver is shown to be capable of separating packets in a two user system where one user is moving while the other is stationary. PMID:23363106

Cho, S E; Song, H C; Hodgkiss, W S

2013-02-01

115

Bandwidth Efficient Turbo Coding For High Speed Mobile Satellite Communications  

Microsoft Academic Search

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

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

1997-01-01

116

Rf-Mems Components In Mobile Communication Terminal  

Microsoft Academic Search

Micro-machined passive components open new perspectives to the integration of multi-standard RF transceivers for mobile communications. The different types of components are reviewed and their potential use in transceiver architectures is outlined

Antriksh Singhal; Gaurang Gupta

2006-01-01

117

Podscanning : audio microcontent and synchronous communication for mobile devices  

E-print Network

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 ...

Wheeler, Patrick Sean

2010-01-01

118

Engaging the Periphery for Visual Communication on Mobile Phones  

Microsoft Academic Search

While mobile phones have become ubiquitous instruments of communication and social interaction, they still require explicit interaction, placing high demands on attention. Engaging the periphery of users' attention offers opportunities for awareness and interaction while reducing demands on attention and risks of disruption. We explore the mobile peripheral design space with Emotipix, an application for camera phones that turns the

Lisa Cowan; William G. Griswold; Louise Barkhuus; James D. Hollan

2010-01-01

119

Near Field Communication and Bluetooth Bridge System for Mobile Commerce  

Microsoft Academic Search

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

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

2006-01-01

120

Stratus: Energy-Efficient Mobile Communication using Cloud Support  

E-print Network

Stratus: Energy-Efficient Mobile Communication using Cloud Support Bhavish Aggarwal Microsoft device. Stratus is a system to reduce this energy consumption by leveraging cloud resources to make data communication on smartphones more efficient. Using a cloud-based proxy, Stratus employs optimizations that adapt

Rajamani, Sriram K.

121

Dynamic participation in a secure conference scheme for mobile communications  

Microsoft Academic Search

We propose a scheme to implement secure digital mobile communications. The scheme can both enable multiple users to hold a secure teleconference and also resolve the problem of allowing a participant to join dynamically or to quit a teleconference already in progress. Essentially, teleconference is a synchronous collaboration session in which participants at remote locations cooperate through wireless communications. Two

Min-Shiang Hwang

1999-01-01

122

Optimization of Wireless Resources for Personal Communications Mobility Tracking  

Microsoft Academic Search

In personal communications applications, users communicate via wireless with a wireline net- work. The wireline network tracks the current location of the user, and can therefore route mes- sages to a user regardless of the user's location. In addition to its impact on signaling within the wireline network, mobility tracking requires the expenditure of wireless resources as well, includ- ing

Upamanyu Madhow; Michael L. Honig; Kenneth Steiglitz

1994-01-01

123

The design of location areas in a GSM-network  

Microsoft Academic Search

The operator of a cellular radio network of the GSM-standard has to group the cells of the network to location areas. When a mobile station in idle mode changes from one cell to the other the mobile station informs the network of its change only if the new cell belongs to a different location area. When an incoming call arrives,

J. Plehn

1995-01-01

124

Looking at the other side of the coin: the search for possible biopositive cognitive effects of the exposure to 900 MHz GSM mobile phone radiofrequency radiation.  

PubMed

Although exposure to electromagnetic radiation in radiofrequency range has caused a great deal of concern globally, radiofrequency radiation has many critical applications in both telecommunication and non-communication fields. The induction of adaptive response phenomena by exposure to radiofrequency radiation as either increased resistance to a subsequent dose of ionizing radiation or resistance to a bacterial infection has been reported recently. Interestingly, the potential beneficial effects of mobile phone radiofrequency radiation are not only limited to the induction of adaptive phenomena. It has previously been indicated that the visual reaction time of university students significantly decreased after a 10 min exposure to radiofrequency radiation emitted by a mobile phone. Furthermore, it has been revealed that occupational exposures to radar radiations decreased the reaction time in radar workers. Based on these findings, it can be hypothesized that in special circumstances, these exposures might lead to a better response of humans to different hazards. Other investigators have also provided evidence that confirms the induction of RF-induced cognitive benefits. Furthermore, some recent reports have indicated that RF radiation may play a role in protecting against cognitive impairment in Alzheimer's disease. In this light, a challenging issue will arise if there are other RF-induced stimulating effects. It is also challenging to explore the potential applications of these effects. Further research may shed light on dark areas of the health effects of short and long-term human exposure to radiofrequency radiation. PMID:24843789

Mortazavi, Seyed Ali Reza; Tavakkoli-Golpayegani, Ali; Haghani, Masoud; Mortazavi, Seyed Mohammad Javad

2014-01-01

125

Looking at the other side of the coin: the search for possible biopositive cognitive effects of the exposure to 900 MHz GSM mobile phone radiofrequency radiation  

PubMed Central

Although exposure to electromagnetic radiation in radiofrequency range has caused a great deal of concern globally, radiofrequency radiation has many critical applications in both telecommunication and non-communication fields. The induction of adaptive response phenomena by exposure to radiofrequency radiation as either increased resistance to a subsequent dose of ionizing radiation or resistance to a bacterial infection has been reported recently. Interestingly, the potential beneficial effects of mobile phone radiofrequency radiation are not only limited to the induction of adaptive phenomena. It has previously been indicated that the visual reaction time of university students significantly decreased after a 10 min exposure to radiofrequency radiation emitted by a mobile phone. Furthermore, it has been revealed that occupational exposures to radar radiations decreased the reaction time in radar workers. Based on these findings, it can be hypothesized that in special circumstances, these exposures might lead to a better response of humans to different hazards. Other investigators have also provided evidence that confirms the induction of RF-induced cognitive benefits. Furthermore, some recent reports have indicated that RF radiation may play a role in protecting against cognitive impairment in Alzheimer’s disease. In this light, a challenging issue will arise if there are other RF-induced stimulating effects. It is also challenging to explore the potential applications of these effects. Further research may shed light on dark areas of the health effects of short and long-term human exposure to radiofrequency radiation. PMID:24843789

2014-01-01

126

Design of Hybrid Mobile Communication Networks for Planetary Exploration  

NASA Technical Reports Server (NTRS)

The Mobile Exploration System Project (MEX) at NASA Ames Research Center has been conducting studies into hybrid communication networks for future planetary missions. These networks consist of space-based communication assets connected to ground-based Internets and planetary surface-based mobile wireless networks. These hybrid mobile networks have been deployed in rugged field locations in the American desert and the Canadian arctic for support of science and simulation activities on at least six occasions. This work has been conducted over the past five years resulting in evolving architectural complexity, improved component characteristics and better analysis and test methods. A rich set of data and techniques have resulted from the development and field testing of the communication network during field expeditions such as the Haughton Mars Project and NASA Mobile Agents Project.

Alena, Richard L.; Ossenfort, John; Lee, Charles; Walker, Edward; Stone, Thom

2004-01-01

127

Presence Aware Location-Based Service For Managing Mobile Communications  

Microsoft Academic Search

Presence technology based on Session Initiation Protocol can be used as an enabling platform for delivering communication and providing event-based services. We present a mobile workforce management solution which integrates fleet management with presence-based communication to show how presence technology can be used to realize location-based communication services. In particular, our solution integrates a user's presence information with their vehicle's

Vishal Kumar Singh; Henning Schulzrinne; Piotr Boni; Boris Elman; David Kenneson

2007-01-01

128

: Mobility and Communication for Cooperation and Coordination  

E-print Network

and communication aspects and issues in the direct control of the devices, both singularly and seen as a whole for machine-to-machine wireless communications modelisation, simulation and evaluation of coordina- tion of the devices machine learning schemes in communication and mo- tion aware algorithms for wireless networked

Ducatelle, Frederick

129

Inferring human mobility using communication patterns.  

PubMed

Understanding the patterns of mobility of individuals is crucial for a number of reasons, from city planning to disaster management. There are two common ways of quantifying the amount of travel between locations: by direct observations that often involve privacy issues, e.g., tracking mobile phone locations, or by estimations from models. Typically, such models build on accurate knowledge of the population size at each location. However, when this information is not readily available, their applicability is rather limited. As mobile phones are ubiquitous, our aim is to investigate if mobility patterns can be inferred from aggregated mobile phone call data alone. Using data released by Orange for Ivory Coast, we show that human mobility is well predicted by a simple model based on the frequency of mobile phone calls between two locations and their geographical distance. We argue that the strength of the model comes from directly incorporating the social dimension of mobility. Furthermore, as only aggregated call data is required, the model helps to avoid potential privacy problems. PMID:25146347

Palchykov, Vasyl; Mitrovi?, Marija; Jo, Hang-Hyun; Saramäki, Jari; Pan, Raj Kumar

2014-01-01

130

Inferring human mobility using communication patterns  

PubMed Central

Understanding the patterns of mobility of individuals is crucial for a number of reasons, from city planning to disaster management. There are two common ways of quantifying the amount of travel between locations: by direct observations that often involve privacy issues, e.g., tracking mobile phone locations, or by estimations from models. Typically, such models build on accurate knowledge of the population size at each location. However, when this information is not readily available, their applicability is rather limited. As mobile phones are ubiquitous, our aim is to investigate if mobility patterns can be inferred from aggregated mobile phone call data alone. Using data released by Orange for Ivory Coast, we show that human mobility is well predicted by a simple model based on the frequency of mobile phone calls between two locations and their geographical distance. We argue that the strength of the model comes from directly incorporating the social dimension of mobility. Furthermore, as only aggregated call data is required, the model helps to avoid potential privacy problems. PMID:25146347

Palchykov, Vasyl; Mitrovi?, Marija; Jo, Hang-Hyun; Saramäki, Jari; Pan, Raj Kumar

2014-01-01

131

Inferring human mobility using communication patterns  

NASA Astrophysics Data System (ADS)

Understanding the patterns of mobility of individuals is crucial for a number of reasons, from city planning to disaster management. There are two common ways of quantifying the amount of travel between locations: by direct observations that often involve privacy issues, e.g., tracking mobile phone locations, or by estimations from models. Typically, such models build on accurate knowledge of the population size at each location. However, when this information is not readily available, their applicability is rather limited. As mobile phones are ubiquitous, our aim is to investigate if mobility patterns can be inferred from aggregated mobile phone call data alone. Using data released by Orange for Ivory Coast, we show that human mobility is well predicted by a simple model based on the frequency of mobile phone calls between two locations and their geographical distance. We argue that the strength of the model comes from directly incorporating the social dimension of mobility. Furthermore, as only aggregated call data is required, the model helps to avoid potential privacy problems.

Palchykov, Vasyl; Mitrovi?, Marija; Jo, Hang-Hyun; Saramäki, Jari; Pan, Raj Kumar

2014-08-01

132

Coded Modulations for Mobile Satellite Communication Channels  

Microsoft Academic Search

The mobile satellite (MSAT) channel is subject to multipath fading, shadowing, Doppler frequency shift, and adjacent channel interference (ACI). Therefore, transmitted signals face severe amplitude and phase distortions. This dissertation investigates various high performance and low decoding complexity coded modulation schemes for reliable voice and data transmissions over the shadowed mobile satellite channel and the Rayleigh fading channel. The dissertation

Dojun Rhee

1995-01-01

133

CURRENT DEGREE PROGRAMS GSM NON-DEGREE  

E-print Network

International Management ** GSM 42 0530 C Marketing ** GSM 42 5004 C Strategy and Business Analysis GSM 42 0555 5004 C Strategy and Business Analysis GSM 51 0555 C M.B.A./M.A. - MASTER OF BUSINESS ADMINISTRATION Analysis GSM 52 0555 C M.B.A./M.A. - MASTER OF BUSINESS ADMINISTRATION/MASTER OF ARTS M.B.A. - Business

Guenther, Frank

134

Mobile satellite communications systems: Toward global personal communications  

Microsoft Academic Search

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

John H. Lodge

1991-01-01

135

Development of a mobile satellite communication unit  

NASA Technical Reports Server (NTRS)

A compact 210(W) x 280(H) x 330(D) mm mobile terminal capable of transmitting voice and data through L-band mobile satellites is described. The Voice Codec can convert an analog voice to or from digital codes at rates of 9.6, 8 and 4.8 kb/s by an MPC algorithm. The terminal functions with a single 12 V power supplied vehicle battery. The equipment can operate at any L-band frequency allocated for mobile uses in a full duplex mode and will soon be put into a field test via Japans's ETS-V satellite.

Suzuki, Ryutaro; Ikegami, Tetsushi; Hamamoto, Naokazu; Taguchi, Tetsu; Endo, Nobuhiro; Yamamoto, Osamu; Ichiyoshi, Osamu

1988-01-01

136

Edgar Nett Mobile Computer Communication 4 Introduction  

E-print Network

, cheap, rich of applications (cameras, mobile phones, music players, smartphones etc) l and being able requires innovative input/output (speech, touch screen, Google glasses) Trend (not only regarding networks

137

Mobile phone emissions and human brain excitability  

Microsoft Academic Search

Objective: To test—via Transcranial Magnetic Stimulation (TMS)—the excitability of each brain hemisphere after 'real' or 'sham' exposure to the electromagnetic field (EMF) generated by a mobile phone operating in the Global System for Mobile Communication (GSM). Methods: Fifteen male volunteers attended two experimental sessions, one week apart, in a cross-over, double-blind paradigm. In one session the signal was turned ON

Florinda Ferreri; Giuseppe Curcio; Patrizio Pasqualetti; Luigi De Gennaro; Rita Fini; Paolo Maria Rossini

2006-01-01

138

The future of railway communications  

Microsoft Academic Search

Today's railway networks are undergoing a renaissance. Digital communications technology will offer new services to operators & passengers. Nokia Siemens Networks (NSN) is steering the evolution of all relevant technology, including LTE (Long Term Evolution) technology to transform both GSM-R (Global System for Mobile Communications Railway) and Broadband on Trains with higher data speeds and more cost-effective, IP-based operations. New

Johann Garstenauer; Sergej Pocuca

2011-01-01

139

Force-based load balancing in co-located UMTS\\/GSM networks  

Microsoft Academic Search

Currently UMTS networks are rolled out to compliment existing GSM networks. As most UMTS mobiles will also support GSM, the question of which system to select for a given service emerges. In order to exploit the differences between radio access technologies, common radio resource management (CRRM) is employed, i.e. common management of the whole radio resources such that the assignment

Andreas Pillekeit; Fariborz Derakhshan; Enrico Jugl; Andreas Mitschele-Thiel

2004-01-01

140

Biological aspects of mobile communication fields  

Microsoft Academic Search

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

James C. Lin

1997-01-01

141

Scalable, error-resilient, and high-performance video communications in mobile wireless environments  

Microsoft Academic Search

A novel mobile communications system is proposed, which provides not only effective but also efficient video access for mobile users when communicating over low-bandwidth error-prone wireless links. The middleware implemented by a mobile proxy server at the mobile support station is designed for the seamless integration of mobile users with video servers, so the specific details of the underlying protocols

Jozsef Vass; Shelley Zhuang; Xinhua Zhuang

2001-01-01

142

Potential markets for a satellite-based mobile communications system  

NASA Technical Reports Server (NTRS)

The objective of the study was to define the market needs for improved land mobile communications systems. Within the context of this objective, the following goals were set: (1) characterize the present mobile communications industry; (2) determine the market for an improved system for mobile communications; and (3) define the system requirements as seen from the potential customer's viewpoint. The scope of the study was defined by the following parameters: (1) markets were confined to U.S. and Canada; (2) range of operation generally exceeded 20 miles, but this was not restrictive; (3) the classes of potential users considered included all private sector users, and non-military public sector users; (4) the time span examined was 1975 to 1985; and (5) highly localized users were generally excluded - e.g., taxicabs, and local paging.

Jamieson, W. M.; Peet, C. S.; Bengston, R. J.

1976-01-01

143

GSM-verkon käyttö etävalvonnassa.  

E-print Network

??Opinnäytetyössä tutkittiin, minkälaisia ratkaisuja GSM-verkon yli tapahtuvaan etävalvontaan ja -ohjaukseen on tarjolla, ja mitä tekniikoita järjestelmät käyttävät datansiirtoon. Tavoitteena oli, että älyverkkolaboratorioon rakennetaan sopiva testiympäristö,… (more)

Serttilä, Jani

2007-01-01

144

High-speed satellite mobile communications: technologies and challenges  

Microsoft Academic Search

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

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

2004-01-01

145

Design of a mobile coastal communications buoy  

E-print Network

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 ...

Hendry-Brogan, Meghan

2004-01-01

146

Mobile satellite service communications tests using a NASA satellite  

NASA Technical Reports Server (NTRS)

Emerging applications of commercial mobile satellite communications include satellite delivery of compact disc (CD) quality radio to car drivers who can select their favorite programming as they drive any distance; transmission of current air traffic data to aircraft; and handheld communication of data and images from any remote corner of the world. Experiments with the enabling technologies and tests and demonstrations of these concepts are being conducted before the first satellite is launched by utilizing an existing NASA spacecraft.

Chambers, Katherine H.; Koschmeder, Louis A.; Hollansworth, James E.; ONeill, Jack; Jones, Robert E.; Gibbons, Richard C.

1995-01-01

147

A Communication Architecture for an Advanced Extravehicular Mobile Unit  

NASA Technical Reports Server (NTRS)

This document describes the communication architecture for the Power, Avionics and Software (PAS) 1.0 subsystem for the Advanced Extravehicular Mobility Unit (AEMU). The following systems are described in detail: Caution Warning and Control System, Informatics, Storage, Video, Audio, Communication, and Monitoring Test and Validation. This document also provides some background as well as the purpose and goals of the PAS subsystem being developed at Glenn Research Center (GRC).

Ivancic, William D.; Sands, Obed S.; Bakula, Casey J.; Oldham, Daniel R.; Wright, Ted; Bradish, Martin A.; Klebau, Joseph M.

2014-01-01

148

Mobile power management for wireless communication networks  

Microsoft Academic Search

For fixed quality-of-service constraints and varying channel interference, how should a mobile node in a wireless network adjust its transmitter power so that energy consumption is minimized? Several transmission schemes are considered, and optimal solutions are obtained for channels with stationary, extraneous interference. A simple dynamic power management algorithm based on these solutions is developed. The algorithm is tested by

John M. Rulnick; Nicholas Bambos

1997-01-01

149

Land-mobile satellite communication system  

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

150

Satellite-aided mobile communications, experiments, applications and prospects  

NASA Technical Reports Server (NTRS)

NASA's ATS-series of satellites were used in a series of communications and position fixing experiments with automotive vehicles, ships and aircraft. Applications of the communications were demonstrated and evaluated for public services including law enforcement, search and rescue, and medical emergency, and for commercial uses in the land and maritime transportation industries. The technical success of the experiments and the demonstrated potential value of the communications prompted a study that concluded an operational satellite-aided system would be a valuable augmentation of planned trunking or cellular type terrestrial mobile radio telephone systems.

Anderson, R. E.; Frey, R. L.; Lewis, J. R.; Milton, R. T.

1980-01-01

151

A satellite system for land-mobile communications in Europe  

NASA Technical Reports Server (NTRS)

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.

Bartholome, P.; Rogard, R.

1988-01-01

152

The design of static and mobile HF communication systems  

Microsoft Academic Search

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

M. Darnell

1986-01-01

153

Communications diversity advantages for the Mobile User Objective System  

Microsoft Academic Search

The UHF radio frequency (RF) band available for the our future military Mobile User Objective System (MUOS) satellite communications system has to contend with the signal scintillation effects encountered from propagation through the ionosphere as well as multipath signals from terrestrial signal reflections that will be prominent with new handheld terminals. These effects cause signal fading which can severely degrade

Per A. Kullstam

2000-01-01

154

Structure and tie strengths in mobile communication networks  

E-print Network

Structure and tie strengths in mobile communication networks J.-P. Onnela* , J. Sarama¨ki*, J. Hyvo consequence that social networks are robust to the removal of the strong ties but fall apart after a phase transition if the weak ties are removed. We show that this coupling significantly slows the diffusion process

Iamnitchi, Adriana

155

Channel-Individual Adaptive Beamforming for Mobile Satellite Communications  

Microsoft Academic Search

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

Thomas Gebauer; Heinz G. Göckler

1995-01-01

156

Remotely controlled communication and control system for limited mobility individuals  

Microsoft Academic Search

Design improvements to a remotely controlled system for patients with limited mobility are described. This system provides communication and control of the room environment with mouse control that can be adapted to the functional need of the user. Analysis is provided on the selection and integration of components within the system as well as an overview of the simulated access

Matthew Goldman; Ettore Cervo; Alexander Melle; Bryan Wilson; Seyitriza Tigrek; Frank Agyei-Ntim; Kimberly E. Newman; Frank Barnes; Michael Blei

2011-01-01

157

Enabling Disconnected Transitive Communication in Mobile Ad Hoc Networks  

Microsoft Academic Search

Recently, mobile ad hoc computing has attracted much at- tentionintheresearchcommunity. Difierentfrommostcur- rentwirelessnetworks,mobilead-hocnetworkshavenoflxed infrastructure, all hosts are capable of movement, and the network is continuously reconstructed into multiple discon- nected clusters. In such environments, connection is unsta- ble, and communication is unpredictable. Current research mainly focuses on providing the same models of communi- cation in this environment as in flxed networks,

Xiangchuan Chen; Amy L. Murphy

2001-01-01

158

Antenna arrays in mobile communications: gain, diversity, and channel capacity  

Microsoft Academic Search

Are antenna arrays in mobile communications different from arrays in other applications? The answer is yes, sometimes, and it is the purpose of this paper to explain, in a tutorial fashion, when this is the case, and what this means for path loss in link calculations. One aspect is the classical gain of an antenna, which we have to understand

J. Bach Andersen

2000-01-01

159

A Channel Sharing Scheme for Cellular Mobile Communications  

E-print Network

A Channel Sharing Scheme for Cellular Mobile Communications Xing Zhang AMPS/PCS Business Leadership, Ontario N2L 3G1 Canada ABSTRACT This paper presents a channel sharing scheme, Neighbor Cell Channel by limiting the usage of sharing channels in the inner­cell region. The channel sharing scheme achieves

Waterloo, University of

160

A Channel Sharing Scheme for Cellular Mobile Communications  

E-print Network

A Channel Sharing Scheme for Cellular Mobile Communications Xing Zhang AMPS PCS Business Leadership, Ontario N2L 3G1 Canada ABSTRACT This paper presents a channel sharing scheme, Neighbor Cell Channel by limiting the usage of sharing channels in the inner-cell region. The channel sharing scheme achieves a tra

Waterloo, University of

161

Sharing Resources In Mobile/Satellite Communications  

NASA Technical Reports Server (NTRS)

Report presents preliminary theoretical analysis of several alternative schemes for allocation of satellite resource among terrestrial subscribers of landmobile/satellite communication system. Demand-access and random-access approaches under code-division and frequency-division concepts compared.

Yan, Tsun-Yee; Sue, Miles K.

1992-01-01

162

QoS management for the next mobile communication network  

NASA Astrophysics Data System (ADS)

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.

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

2004-04-01

163

Spread spectrum mobile communication experiment using ETS-V satellite  

NASA Technical Reports Server (NTRS)

The spread spectrum technique is attractive for application to mobile satellite communications, because of its random access capability, immunity to inter-system interference, and robustness to overloading. A novel direct sequence spread spectrum communication equipment is developed for land mobile satellite applications. The equipment is developed based on a matched filter technique to improve the initial acquisition performance. The data rate is 2.4 kilobits per sec. and the PN clock rate is 2.4552 mega-Hz. This equipment also has a function of measuring the multipath delay profile of land mobile satellite channel, making use of a correlation property of a PN code. This paper gives an outline of the equipment and the field test results with ETS-V satellite.

Ikegami, Tetsushi; Suzuki, Ryutaro; Kadowaki, Naoto; Taira, Shinichi; Sato, Nobuyasu

1990-01-01

164

Coherent versus noncoherent signaling for satellite-aided mobile communications  

NASA Technical Reports Server (NTRS)

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.

Davarian, F.; Sumida, J.

1986-01-01

165

The application of mobile satellite services to emergency response communications  

NASA Technical Reports Server (NTRS)

The application of an integrated satellite/terrestrial emergency response communications system in disaster relief operations is discussed. Large area coverage communications capability, full-time availability, a high degree of mobility, plus reliability, are pointed out as criteria for an effective emergency communications system. Response time is seen as a major factor determining the possible survival and/or protection of property. These criteria, can not be met by existing communications systems and complete blackouts were experienced during the past decades caused by either interruption or destruction of existing power lines, and overload or inadequacy of remaining lines. Several emergency cases, caused by either hurricanes, tornados, or floods, during which communication via satellite was instrumental to inform rescue and relief teams, are described in detail. Seismic Risk Maps and charts of Major Tectonic Plates Earthquake Epicenters are given, and it is noted that, 35 percent of the U.S. population is living in critical areas. National and international agreements for the implementation of a satellite-aided global Search and Rescue Program is mentioned. Technological and economic breakthroughs are still needed in large multibeam antennas, switching circuits, and low cost mobile ground terminals. A pending plan of NASA to initiate a multiservice program in 1982/83, with a Land Mobile Satellite capability operating in the 806 - 890 MHz band as a major element, may help to accelerate the needed breakthroughs.

Freibaum, J.

1980-01-01

166

Frequency diversity for OFDM mobile communication via underwater acoustic channels  

NASA Astrophysics Data System (ADS)

The major constraint on the performance of orthogonal frequency division multiplexing (OFDM) based underwater acoustic (UWA) communication is to keep subcarriers orthogonal. In this paper, Doppler estimation and the respective compensation technique along with various diversity techniques were deliberated for OFDM-based systems best suited for underwater wireless information exchange. In practice, for mobile communication, adjustment and tuning of transducers in order to get spatial diversity is extremely difficult. Considering the relatively low coherence bandwidth in UWA, the frequency diversity design with the Doppler compensation function was elaborated here. The outfield experiments of mobile underwater acoustic communication (UWAC) based on OFDM were carried out with 0.17 bit/(s·Hz) spectral efficiency. The validity and the dependability of the scheme were also analyzed.

Qiao, Gang; Wang, Wei; Guo, Ran; Khan, Rehan; Wang, Yue

2012-03-01

167

MSAT aeronautical mobile satellite communications terminal development  

NASA Technical Reports Server (NTRS)

CAL has undertaken the development of a new aeronautical mobile terminal for the North American MSAT market. The terminal is to meet the MSAT standard and is aimed in particular at the 300,000 general aviation and business aircraft in North America. The terminals are therefore relatively low cost and small in size when compared to those currently being produced for larger airline aircraft. The terminal incorporates a top mounted mechanical steered antenna and a unique antenna steering subsystem. An overview of the terminal design is presented.

Sutherland, C. A.; Sydor, J. T.

1995-01-01

168

Open Innovation in Mobile and Convergent Communications  

NASA Astrophysics Data System (ADS)

The concept of open innovation seems to be very well suited to information and communication technologies. In the first place, as in any other field, the complexity of the new technology makes it necessary for companies to use ideas, processes and inventions from other players. As in any other field, we need the collaboration of the university, of SMEs, of inventors, and of the general public.

Jiménez, José

169

IEEE Communications Magazine August 2003144 0163-6804/03/$17.00 2003 IEEE TOPICS IN CIRCUITS FOR COMMUNICATIONS  

E-print Network

such as Global System for Mobile Communications (GSM) and wideband code-division multiple access (WCDMA of the system-level design parameters of RF transceivers are summarized in Fig. 1. As consumer products, cell for lower cost and hence system-on- chip (SoC) design has inevitably brought up CMOS technology as a serious

Razavi, Behzad

170

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

E-print Network

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

Telek, Miklós

171

Single antenna interference cancellation (SAIC) for GSM networks  

Microsoft Academic Search

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

Ayman Mostafa; Rich Kobylinski; Ivica Kostanic; Mark Austin

2003-01-01

172

Cryptanalysis of the A5\\/1 GSM Stream Cipher  

Microsoft Academic Search

AS\\/1 is the stream cipher used in most Europem countries in order toensure privacy of conversations in GSM mobile phones. In this paper wedescribe attacks on this cipher with total work complexity 2 a9'9 of AS\\/1clockings given 2 2's known plaintext. This is the best known result withrespect to the total work complexity.

Eli Biham; Orr Dunkelman

2000-01-01

173

Transferring Voice using SMS over GSM Network  

E-print Network

The paper presents a methodology of transmitting voice in SMS (Short Message Service) over GSM network. Usually SMS contents are text based and limited to 140 bytes. It supports national and international roaming, but also supported by other telecommunication such as TDMA (Time Division Multiple Access), CDMA (Code Division Multiple Access) as well. It can sent/ receive simultaneously with other services. Such features make it favorable for this methodology. For this an application is developed using J2ME platform which is supported by all mobile phones in the world. This algorithm's test is conducted on N95 having Symbian Operating System (OS).

Khan, Muhammad Fahad

2011-01-01

174

The Globalstar mobile satellite system for worldwide personal communications  

NASA Astrophysics Data System (ADS)

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.

Wiedeman, Robert A.; Viterbi, Andrew J.

175

Monitoring heart disease and diabetes with mobile internet communications.  

PubMed

A telemedicine system is described for monitoring vital signs and general health indicators of patients with cardiac and diabetic conditions. Telemetry from wireless sensors and readings from other instruments are combined into a comprehensive set of measured patient parameters. Using a combination of mobile device applications and web browser, the data can be stored, accessed, and displayed using mobile internet communications to the central server. As an extra layer of security in the data transmission, information embedded in the data is used in its verification. The paper highlights features that could be enhanced from previous systems by using alternative components or methods. PMID:23213330

Mulvaney, David; Woodward, Bryan; Datta, Sekharjit; Harvey, Paul; Vyas, Anoop; Thakker, Bhaskar; Farooq, Omar; Istepanian, Robert

2012-01-01

176

Monitoring Heart Disease and Diabetes with Mobile Internet Communications  

PubMed Central

A telemedicine system is described for monitoring vital signs and general health indicators of patients with cardiac and diabetic conditions. Telemetry from wireless sensors and readings from other instruments are combined into a comprehensive set of measured patient parameters. Using a combination of mobile device applications and web browser, the data can be stored, accessed, and displayed using mobile internet communications to the central server. As an extra layer of security in the data transmission, information embedded in the data is used in its verification. The paper highlights features that could be enhanced from previous systems by using alternative components or methods. PMID:23213330

Mulvaney, David; Woodward, Bryan; Datta, Sekharjit; Harvey, Paul; Vyas, Anoop; Thakker, Bhaskar; Farooq, Omar; Istepanian, Robert

2012-01-01

177

The design of static and mobile HF communication systems  

NASA Astrophysics Data System (ADS)

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.

Darnell, M.

1986-03-01

178

Near field communication: getting in touch with mobile users.  

PubMed

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

Hoy, Matthew B

2013-01-01

179

NASA's mobile satellite communications program; ground and space segment technologies  

NASA Technical Reports Server (NTRS)

This paper describes the Mobile Satellite Communications Program of the United States National Aeronautics and Space Administration (NASA). The program's objectives are to facilitate the deployment of the first generation commercial mobile satellite by the private sector, and to technologically enable future generations by developing advanced and high risk ground and space segment technologies. These technologies are aimed at mitigating severe shortages of spectrum, orbital slot, and spacecraft EIRP which are expected to plague the high capacity mobile satellite systems of the future. After a brief introduction of the concept of mobile satellite systems and their expected evolution, this paper outlines the critical ground and space segment technologies. Next, the Mobile Satellite Experiment (MSAT-X) is described. MSAT-X is the framework through which NASA will develop advanced ground segment technologies. An approach is outlined for the development of conformal vehicle antennas, spectrum and power-efficient speech codecs, and modulation techniques for use in the non-linear faded channels and efficient multiple access schemes. Finally, the paper concludes with a description of the current and planned NASA activities aimed at developing complex large multibeam spacecraft antennas needed for future generation mobile satellite systems.

Naderi, F.; Weber, W. J.; Knouse, G. H.

1984-01-01

180

Cockpit weather graphics using mobile satellite communications  

NASA Astrophysics Data System (ADS)

Many new companies are pushing state-of-the-art technology to bring a revolution in the cockpits of General Aviation (GA) aircraft. The vision, according to Dr. Bruce Holmes - the Assistant Director for Aeronautics at National Aeronautics and Space Administration's (NASA) Langley Research Center, is to provide such an advanced flight control system that the motor and cognitive skills you use to drive a car would be very similar to the ones you would use to fly an airplane. We at ViGYAN, Inc., are currently developing a system called the Pilot Weather Advisor (PWxA), which would be a part of such an advanced technology flight management system. The PWxA provides graphical depictions of weather information in the cockpit of aircraft in near real-time, through the use of broadcast satellite communications. The purpose of this system is to improve the safety and utility of GA aircraft operations. Considerable effort is being extended for research in the design of graphical weather systems, notably the works of Scanlon and Dash. The concept of providing pilots with graphical depictions of weather conditions, overlaid on geographical and navigational maps, is extremely powerful.

Seth, Shashi

181

Breaking GSM with rainbow Tables  

E-print Network

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.

Meyer, Steven

2011-01-01

182

An Extended TAM for Subscribers’ Adoption of Mobile Data Services Provided by Wireless Communication Systems  

Microsoft Academic Search

Wireless communication systems are one kind of EIS (Enterprise Information Systems) for mobile carriers. One of the major\\u000a applications of wireless communication systems is to provide mobile data services to subscribers. Why do subscribers use mobile\\u000a data services? The answer is crucial to the improvement of wireless communication systems. This study applies TAM (Technology\\u000a Acceptance Model) and mobile subscriber experience

Jiayin Qi; Huaying Shu; Jianqiu Zeng

183

Automatic Mobile Vehicle for Adaptive Real-Time Communication Relay  

Microsoft Academic Search

For the currently popular WiFi networks, the problem of communication blind spots is more acute, since the access points (APs) are not placed according to a central plan. In this paper, we design an Cyber physical system (CPS) based on an automatic mobile vehicle (AMV) to guarantee the quality of service (QoS) of real-time applications in WiFi networks. When a

Hai Hu; Furong Wang; Fan Zhang; Weijia Jia; Ge Tang

2009-01-01

184

1 Edgar Nett Mobile Computer Communication SS'10 Wireless LANs  

E-print Network

) and QoS, take their time (e.g. IEEE 802.11a,g and 802.1x) Ultimate goal: Be as good as LAN's #12;3 Edgar Computer Communication SS'10 IEEE 802.11 (WLAN) Characteristics: Worldwide mostly used, available in most.g. 802.11a and g)) Bluetooth Industry standard for WPAN (adopted in 802.15) #12;5 Edgar Nett Mobile

185

Mobile communication research in Asia: changing technological and intellectual geopolitics?  

Microsoft Academic Search

This article reviews Asian mobile communication research since the mid-1990s. First, it identifies key research institutes and funding agencies, not only in Asia but also worldwide public (e.g., the Canadian IDRC) and private (e.g., Microsoft) organizations. It then summarizes the areas of research at micro, meso, and macro levels, including their main topics, methods, and findings, and debates that result

Jack Linchuan Qiu

2010-01-01

186

SUBMITTED TO IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING 1 Building a Communication Bridge with Mobile  

E-print Network

SUBMITTED TO IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING 1 Building a Communication as mobile hubs to provide communication services on-demand. This capability is especially valuable in disaster response scenarios where there is no communication infrastructure. In such scenarios, mobile hubs

Minnesota, University of

187

Interference Analysis for an Aeronautical Mobile Airport Communications System  

NASA Technical Reports Server (NTRS)

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

Wilson, Jeffrey D.; Kercewski, Robert J.

2010-01-01

188

Planar array design and analysis on direction of arrival estimation for mobile communication systems   

E-print Network

The demand of wireless communication has increased significantly in the past few decades due to huge demand to deliver multimedia content instantly. The expansion of mobile content paired with affordable mobile devices ...

Sanudin, Rahmat

2014-06-30

189

An on-line monitoring system of temperature of conductors and fittings based on GSM SMS and Zigbee  

Microsoft Academic Search

An on-line monitoring system of temperature of conductors and fittings based on GSM SMS and Zigbee is produced in this paper, by which the temperature of conductors and fittings can be monitored in real-time and some accidents caused by the increased temperature can be avoided. The principle and the feature of GSM SMS and Zigbee communication are analyzed. The work

Xin-Bo Huang; Qin-Dong Sun; Han Xiao-yan

2008-01-01

190

Omni-directional L-band antenna for mobile communications  

NASA Technical Reports Server (NTRS)

The principle and design of an L-band omni-directional mobile communication antenna are discussed. The antenna is a circular wave guide aperture with hybrid circuits attached to higher order mode excitation. It produces polarized and symmetric two split beams in elevation. The circular waveguide is fed by eight probes with a 90 degree phase shift between their inputs. Radiation pattern characteristics are controlled by adjusting the aperture diameter and mode excitation. This antenna satisfies gain requirements as well as withstanding the harsh environment.

Kim, C. S.; Moldovan, N.; Kijesky, J.

1988-01-01

191

More About Lens Antenna For Mobile/Satellite Communication  

NASA Technical Reports Server (NTRS)

Report presents additional details of design of proposed phased-array antenna described in "Lens Antenna for Mobile/Satellite Communication" (NPO-16948). Intended to be compact and to lie flat on top of vehicle on ground. Transmits and receives circularly polarized radiation in frequency ranges of 821 to 825 MHz and 860 to 870 MHz. Transmitting and receiving beams electronically steerable to any of 48 evenly spaced directions to provide complete azimuth coverage, and would be fixed, but wide, in elevation, to provide coverage at elevation angles from 20 degrees to 60 degrees.

Rahmat-Samii, Y.; Bodnar, D. G.; Rainer, B. K.

1990-01-01

192

Channel models for satellite communication by mobile land users  

NASA Astrophysics Data System (ADS)

The paper investigates three different models for the data communication channel between satellites and land mobile stations. One model is based on the statistical description of the received-power pdf, while the other two models, the Gilbert-Elliott and a 4-state model, describe the generation of digital error patterns. Easy-to-handle methods for the determination of the parameters are given for each model. The quality of the models is demonstrated by comparing their statistical properties with those of stored link measurements in regard to block error probability density function, the gap distribution, and the packet error probability with error correction.

Cygan, Daniel; Dippold, Michael; Finkenzeller, Johann

1988-12-01

193

Propagation issues for emerging mobile and portable communications: A systems perspective  

NASA Technical Reports Server (NTRS)

The viewpoint of a system engineer regarding the format of propagation information and models suitable for the design of mobile and portable satellite communications systems for the following services: audio broadcast, two way voice, and packet data is presented. Topics covered include: propagation impairments for portable indoor reception in satellite communications systems; propagation impairments and mitigation techniques for mobile satellite communications systems; characterization of mobile satellite communications channels in the presence of roadside blockage when interleaving and FEC coding are implemented; characterization of short-term mobile satellite signal variations; and characterization of long-term signal variations.

Golshan, Nasser

1993-01-01

194

Robust and Cost-Efficient Communication Based on SNMP in Mobile Networks  

NASA Astrophysics Data System (ADS)

A main challenge in the design of this mobile network is the development of dynamic routing protocols that can efficiently find routes between two communicating nodes. Multimedia streaming services are receiving considerable interest in the mobile network business. An entire mobile network may change its point of attachment to the Internet. The mobile network is operated by a basic specification to support network mobility called Network Mobility (NEMO) Basic Support. However, NEMO basic Support mechanism has some problem in continuous communication. In this paper, we propose robust and cost-efficient algorithm. And we simulate proposed method and conclude some remarks.

Ryu, Sang-Hoon; Baik, Doo-Kwon

195

Radial microstrip slotline feed network for circular mobile communications array  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

196

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

NASA Technical Reports Server (NTRS)

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.

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

1993-01-01

197

Multi-purpose HealthCare Telemedicine Systems with mobile communication link support  

PubMed Central

The provision of effective emergency telemedicine and home monitoring solutions are the major fields of interest discussed in this study. Ambulances, Rural Health Centers (RHC) or other remote health location such as Ships navigating in wide seas are common examples of possible emergency sites, while critical care telemetry and telemedicine home follow-ups are important issues of telemonitoring. In order to support the above different growing application fields we created a combined real-time and store and forward facility that consists of a base unit and a telemedicine (mobile) unit. This integrated system: can be used when handling emergency cases in ambulances, RHC or ships by using a mobile telemedicine unit at the emergency site and a base unit at the hospital-expert's site, enhances intensive health care provision by giving a mobile base unit to the ICU doctor while the telemedicine unit remains at the ICU patient site and enables home telemonitoring, by installing the telemedicine unit at the patient's home while the base unit remains at the physician's office or hospital. The system allows the transmission of vital biosignals (3–12 lead ECG, SPO2, NIBP, IBP, Temp) and still images of the patient. The transmission is performed through GSM mobile telecommunication network, through satellite links (where GSM is not available) or through Plain Old Telephony Systems (POTS) where available. Using this device a specialist doctor can telematically "move" to the patient's site and instruct unspecialized personnel when handling an emergency or telemonitoring case. Due to the need of storing and archiving of all data interchanged during the telemedicine sessions, we have equipped the consultation site with a multimedia database able to store and manage the data collected by the system. The performance of the system has been technically tested over several telecommunication means; in addition the system has been clinically validated in three different countries using a standardized medical protocol. PMID:12694629

Kyriacou, E; Pavlopoulos, S; Berler, A; Neophytou, M; Bourka, A; Georgoulas, A; Anagnostaki, A; Karayiannis, D; Schizas, C; Pattichis, C; Andreou, A; Koutsouris, D

2003-01-01

198

Robust Timing Synchronization in Aeronautical Mobile Communication Systems  

NASA Technical Reports Server (NTRS)

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.

Xiong, Fu-Qin; Pinchak, Stanley

2004-01-01

199

Investigation of the performance of EOTD for GSM users in telematics applications  

NASA Astrophysics Data System (ADS)

Location-based services have been standardized for incorporation into 3rd generation wireless communications as a result of the Federal Communications Commission"s (FCC) mandate on wireless carriers to provide automatic location information (ALI) during emergency911 calls. This mandate has driven the wireless carriers to explore terrestrial, satellite, and hybrid based location technology solutions. This paper presents a communications model that investigates the position accuracyof a Global Standard Mobile (GSM) phone employing the enhanced observed time difference (EOTD) location technology. The EOTD positioning technique requires the mobile station (MS) to detect signals from at least three base stations (BS). This studyassumes the three BSs are synchronized in time. For a given BS geometry with respect to the MS, a Monte Carlo simulation was performed to assess the two-dimensional position accuracyof the MS in Rayleigh and Ricean fading channels. In each channel, a Monte Carlo simulation was performed for a good and a bad BS-to-MS geometry. The paper concludes with a list of pros/cons of implementing EOTD as a location technologyenabler in telematics applications.

Sharawi, Mohammad S.; Aloi, Daniel N.

2003-08-01

200

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

E-print Network

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

Krishnamurthy, Srikanth

201

A Novel Broadband Omni-Directional Circularly Polarized Antenna for Mobile Communications  

E-print Network

A Novel Broadband Omni-Directional Circularly Polarized Antenna for Mobile Communications Xulin.tentzeris@ece.gatech.edu Abstract--This paper presents a new broadband omni-directional circularly polarized (CP) antenna for mobile is achieved. Keywords-broadband antenna; circularly polarized antenna; omni-directional antenna; mobile

Tentzeris, Manos

202

Motion Prediction in Mobile Communication Systems from a Historical and Geographical Perspective  

Microsoft Academic Search

Motion prediction serves to improve quality of service for mobile hosts in mobile communication systems. Much work has been done to make motion prediction using statistical method or shadow clusters. In this study we try to attack this problem through the statistical method and ANFIS (adaptive neural-fuzzy inference system) method. In the simulation process, we generated mobile host motion pattern

Zhiwei Cen; Hong Chen; Xiaomei Liu

203

Considerations of digital phase modulation for narrowband satellite mobile communication  

NASA Technical Reports Server (NTRS)

The Inmarsat-M system for mobile satellite communication is specified as a frequency division multiple access (FDMA) system, applying Offset Quadrature Phase Shift Keying (QPSK) for transmitting 8 kbit/sec in 10 kHz user channel bandwidth. We consider Digital Phase Modulation (DPM) as an alternative modulation format for INMARSAT-M. DPM is similar to Continuous Phase Modulation (CPM) except that DPM has a finite memory in the premodular filter with a continuous varying modulation index. It is shown that DPM with 64 states in the VA obtains a lower bit error rate (BER). Results for a 5 kHz system, with the same 8 kbit/sec transmitted bitstream, is also presented.

Grythe, Knut

1990-01-01

204

Design of a GSM Vocoder using SpecC Methodology  

Microsoft Academic Search

This report describes the design of a voice encoder\\/decoder (vocoder) based on the European GSM standardemploying the system-level design methodology developed at UC Irvine. The project is a result of a cooperationbetween UCI and Motorola to demonstrate the SpecC methodology. Starting from the abstract executablespecification written in SpecC different design alternatives concerning the system architecture (componentsand communication) are explored and

Andreas Gerstlauer; Shuqing Zhao; Daniel D. Gajski

1999-01-01

205

An overview of the OmniTRACS: The first operational mobile Ku-band satellite communications  

NASA Technical Reports Server (NTRS)

The service features of the OmniTRACS system developed by Omninet Communications Services of Los Angeles, California are described. This system is the first operational mobile Ku-band satellite communications system that provides two-way messaging and position determination and reporting services to mobile users on a nationwide basis. The system uses existing Ku-band satellites under a secondary international allocation for mobile satellite services.

Salmasi, Allen

1988-01-01

206

75 FR 32984 - Policy on the Retention of Supporting Documents and the Use of Electronic Mobile Communication...  

Federal Register 2010, 2011, 2012, 2013, 2014

...of electronic mobile communication/ tracking technology...of an association, business, labor union, etc...motor carrier uses Global Positioning Systems...other electronic mobile communication/tracking technology...ordinary course of its business, FMCSA has the...

2010-06-10

207

Mobile health-monitoring system through visible light communication.  

PubMed

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

Tan, Yee-Yong; Chung, Wan-Young

2014-01-01

208

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

209

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

E-print Network

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

Lin, Xi

210

Research Issues for Data Communication in Mobile Ad-Hoc Network Database Systems Leslie D. Fife, Le Gruenwald*  

E-print Network

, servers have unlimited power and communicate with mobile hosts over a wireless connection. Mobile clients of data push and data pull, but it also allows the clients to communicate directly with each other withoutResearch Issues for Data Communication in Mobile Ad-Hoc Network Database Systems Leslie D. Fife, Le

Gruenwald, Le

211

Mocotos: Mobile Communications Tools for Children with Special Needs  

E-print Network

without special interventions. These children are trained in Augmentative and Alternative Communication verbally communicate, augmentative visual communications tools can enable them to get their needs met for augmentative and visual communication. We then describe a prototype Mocoto. Finally we conclude

Hayes, Gillian R.

212

Eavesdropping on GSM: state-of-affairs  

E-print Network

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...

Broek, Fabian van den

2011-01-01

213

Evaluation of Ad-Hoc and Mobility Architectures using Satellite Communications  

E-print Network

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

Paris-Sud XI, Université de

214

BeamSwitch: System Solution for Energy-Efficient Directional Communication on Mobile Devices  

E-print Network

1 BeamSwitch: System Solution for Energy-Efficient Directional Communication on Mobile Devices of Electrical & Computer Engineering, Rice University, Houston, TX 77005 Abstract: Directional communication has the potential to improve the energy efficiency of wireless communication without sacrificing its quality. We

Zhong, Lin

215

A Robust and Affordable Mobile Communications System for Emergency Management and Crisis Response  

E-print Network

A Robust and Affordable Mobile Communications System for Emergency Management and Crisis Response Vegas, Nevada, USA. The Need for "First Responder" Integrated Emergency Communications In today's hyper, emergency managers, and relief workers may struggle to communicate during a crisis. Further, we do not all

Bowman, Michael

216

GSM-verkon kautta tapahtuvan laiteohjauksen tekniikka.  

E-print Network

??Opinnäytetyö tehtiin Oulun yliopiston Tulevaisuuden tuotantoteknologiat -tutkimusryhmälle. Työn tavoitteena oli perehtyä GSM-verkon kautta tapahtuvan laiteohjauksen tekniikkaan ja selvittää markkinoilla olevan tekniikan komponentit, niiden hinta ja… (more)

Taivainen, Petri

2013-01-01

217

Using satellite communications for a mobile computer network  

NASA Technical Reports Server (NTRS)

The topics discussed include the following: patrol car automation, mobile computer network, network requirements, network design overview, MCN mobile network software, MCN hub operation, mobile satellite software, hub satellite software, the benefits of patrol car automation, the benefits of satellite mobile computing, and national law enforcement satellite.

Wyman, Douglas J.

1993-01-01

218

Adaptive digital beamforming for a CDMA mobile communications payload  

NASA Technical Reports Server (NTRS)

In recent years, Spread-Spectrum Code Division Multiple Access (CDMA) has become a very popular access scheme for mobile communications due to a variety of reasons: excellent performance in multipath environments, high scope for frequency reuse, graceful degradation near saturation, etc. In this way, a CDMA system can support simultaneous digital communication among a large community of relatively uncoordinated users sharing a given frequency band. Nevertheless, there are also important problems associated with the use of CDMA. First, in a conventional CDMA scheme, the signature sequences of asynchronous users are not orthogonal and, as the number of active users increases, the self-noise generated by the mutual interference between users considerably degrades the performance, particularly in the return link. Furthermore, when there is a large disparity in received powers - due to differences in slant range or atmospheric attenuation - the non-zero cross-correlation between the signals gives rise to the so-called near-far problem. This leads to an inefficient utilization of the satellite resources and, consequently, to a drastic reduction in capacity. Several techniques were proposed to overcome this problem, such as Synchronized CDMA - in which the signature sequences of the different users are quasi-orthogonal - and power control. At the expense of increased network complexity and user coordination, these techniques enable the system capacity to be restored by equitably sharing the satellite resources among the users. An alternative solution is presented based upon the use of time-reference adaptive digital beamforming on board the satellite. This technique enables a high number of independently steered beams to be generated from a single phased array antenna, which automatically track the desired user signal and null the unwanted interference source. In order to use a time-reference adaptive antenna in a communications system, the main challenge is to obtain a reference signal highly correlated with the desired user signal and uncorrelated with the interferences. CDMA lends itself very easily to the generation of such a reference signal, thanks to the a priori knowledge of the user's signature sequence. First, the integration of an adaptive antenna in an asynchronous CDMA system is analyzed. The adaptive antenna system can provide increased interference rejection - much higher than that afforded by the code alone - and, since CDMA is mainly interference limited, any reduction in interference converts directly and linearly into an increase in capacity. Analyses and computer simulations are presented that show how an asynchronous CDMA system incorporating adaptive beamforming can provide at least as much capacity as a synchronous system. More importantly, the proposed concept allows the near-far effect to be mitigated without requiring a tight coordination of the users in terms of transmitted power control or network synchronization. The system is extremely robust to the near-far effect because the signals reaching the satellite from directions other than that of the desired user - which are likely to have different power levels - are adaptively canceled by the antenna. Finally, a payload architecture is presented that illustrates the practical implementation of this concept. This digital payload architecture demonstrates that with the advent of high performance CMOS digital processing, the on-board implementation of complex DSP techniques - in particular Digital Beamforming - has become possible, being most attractive for Mobile Satellite Communications.

Munoz-Garcia, Samuel G.; Ruiz, Javier Benedicto

1993-01-01

219

Maintaining optimal communication chains in robotic sensor networks using mobility control  

Microsoft Academic Search

Electronic chaining is the formation, and mainte- nance, of a linked communication chain that maximizes the end- to-end throughput using a cooperative team of mobile robotic relays. For this paper, an optimal communication chain is defined using the signal-to-noise ratio (SNR) of the communication links along the chain. By using the SNR of the individual communication channels, instead of relative

Cory Dixon; Eric W. Frew

2007-01-01

220

An Active K-Band Receive Slot Array for Mobile Satellite Communications  

NASA Technical Reports Server (NTRS)

An active receive slot array has been developed for operation in the downlink frequency band, 19.914-20.064 GHz, of NASA's Advanced Communication Technology Satellite (ACTS) for the ACTS Mobile Terminal (AMT) project.

Tulintseff, A. N.; Lee, K. A.; Sukamto, L. M.; Chew, W.

1994-01-01

221

13 Edgar Nett Mobile Computer Communication SS'10 Signal propagation ranges  

E-print Network

Multiplexing medium characteristics Basic schemes Amplitude Modulation (AM) Frequency Modulation (FM) Phase Modulation (PM) #12;17 Edgar Nett Mobile Computer Communication SS'10 Modulation and demodulation synchronization decision digital dataanalog demodulation radio carrier analog baseband signal 101101001 radio

222

Are GSM phones THE solution for localization?  

Microsoft Academic Search

In this paper, we argue that localization solution based on cellular phone technology, specifically GSM phones, is a sufficient and attractive option in terms of coverage and accuracy for a wide range of indoor, outdoor, and place- based location-aware applications. We present preliminary results that indicate that GSM-based localization systems have the potential to detect the places that people visit

Alex Varshavsky; Mike Y. Chen; Eyal De Lara; Jon Froehlich; Dirk Haehnel; Jeffrey Hightower; Anthony LaMarca; Fred Potter; Timothy Sohn; Karen Tang; Ian Smith

2006-01-01

223

Mobile ad hoc networks for oceanic aircraft communications  

E-print Network

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 ...

Kingsbury, Ryan W

2009-01-01

224

No influence of acute RF exposure (GSM-900, GSM-1800, and UMTS) on mouse retinal ganglion cell responses under constant temperature conditions.  

PubMed

Possible non-thermal effects of radio frequency electromagnetic fields (RF-EMF) on retinal ganglion cells were studied in vitro under conditions of constant temperature. Isolated mouse retinae were exposed to GSM-900, GSM-1800, and universal mobile telecommunication system (UMTS) RF-EMF applying specific absorption rates (SAR) of 0 (sham), 0.02, 0.2, 2, and 20?W/kg. Temperature was kept constant within ±0.5 to 1?°C for GSM-900 and ±0.5?°C for GSM-1800 and UMTS. Responses of retinal ganglion cells to light stimuli of three intensities (0.5, 16, and 445?lx) were recorded before, during, and up to 35?min after exposure. Experiments were performed under double-blind conditions. Changes in light responses during and after exposure were determined for each condition (RF-EMF; SAR value; light intensity) with respect to the responses before exposure, respectively. Changes were calculated using the Euclidian distance of the n-dimensional response vectors, respectively. Some changes already occurred during sham (0?W/kg) exposure, reflecting the intrinsic variability in retinal ganglion cell responses. Comparison of the distance values from sham exposure with those from actual exposure yielded no significant differences. In addition, linear regression analysis of the distance values versus SAR values yielded no consistent dependence of light response changes. From these results we conclude that RF-EMF exposure at three mobile phone frequencies (GSM-900, GSM-1800, UMTS) and SARs up to 20?W/kg has no acute effects on retinal ganglion cell responses under constant temperature conditions. Bioelectromagnetics. © 2013 Wiley Periodicals, Inc. PMID:24115076

Ahlers, Malte T; Ammermüller, Josef

2013-09-21

225

A Survey of Routing Techniques for Mobile Communications Networks  

Microsoft Academic Search

. 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

S. Ramanathan; Martha Steenstrup

1996-01-01

226

A combined application of lossless and lossy compression in ECG processing and transmission via GSM-based SMS.  

PubMed

Abstract This paper presents a software-based scheme for reliable and robust Electrocardiogram (ECG) data compression and its efficient transmission using Second Generation (2G) Global System for Mobile Communication (GSM) based Short Message Service (SMS). To achieve a firm lossless compression in high standard deviating QRS complex regions and an acceptable lossy compression in the rest of the signal, two different algorithms have been used. The combined compression module is such that it outputs only American Standard Code for Information Interchange (ASCII) characters and, hence, SMS service is found to be most suitable for transmitting the compressed signal. At the receiving end, the ECG signal is reconstructed using just the reverse algorithm. The module has been tested to all the 12 leads of different types of ECG signals (healthy and abnormal) collected from the PTB Diagnostic ECG Database. The compression algorithm achieves an average compression ratio of ?22.51, without any major alteration of clinical morphology. PMID:25534118

Mukhopadhyay, S K; Mitra, S; Mitra, M

2015-02-01

227

Cross Layer Design for Mobile Ad-Hoc Unmanned Aerial Vehicle Communication Networks  

E-print Network

Cross Layer Design for Mobile Ad-Hoc Unmanned Aerial Vehicle Communication Networks Abdel Ilah of wireless network that is formed by a collection of mobile nodes. Each node in such network has the coverage area and reduce the number of hops. Meanwhile, we designed a new Medium Access Control (MAC

Dong, Liang

228

The Interoperability Problem: Bringing together Mobile Agents and Agent Communication Languages  

Microsoft Academic Search

Interoperability is a central issue for both the mobile agents community and the wider agents community. Unfor- tunately, the interoperability concerns are different between the two communities. As a result, inter-agent communica- tion is an issue that has been addressed in a limited man- ner by the mobile agents community. Agent communication languages (ACLs) have been developed as tools with

Yannis Labrou; Timothy W. Finin; Yun Peng

1999-01-01

229

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

E-print Network

IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 56, NO. 5, MAY 2008 743 Mobility Enhanced Smart Antenna. Index Terms--Mobility estimation, adaptive sectoring, smart antenna, and CDMA uplink capacity. I antenna systems at base stations. While smart antenna is often associated with adaptive beam forming, our

Krishnamurthy, Vikram

230

A Low-Cost Cellular Mobile Communication System: A Hierarchical Optimization Network Resource Planning Approach  

Microsoft Academic Search

This paper deals with the optimization of the design and radio network resource planning for cellular mobile communication systems. The key element to be considered for mobile network planning is cost. A hierarchical optimization planning method (HOP) is utilized since there are so many factors like system performance, terrain features, base station parameters, and cost factors which are involved in

Qi Hao; Boon-hee Soong; Erry Gunawan; Jin-teong Ong; Cheong-Boon Soh; Li Zheng

1997-01-01

231

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

ERIC Educational Resources Information Center

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…

Norris, Daniel T.

2007-01-01

232

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

E-print Network

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

California at San Diego, University of

233

The design of a linear L-band high power amplifier for mobile communication satellites  

NASA Technical Reports Server (NTRS)

A linear L-band solid state high power amplifier designed for the space segment of the Mobile Satellite (MSAT) mobile communication system is described. The amplifier is capable of producing 35 watts of RF power with multitone signal at an efficiency of 25 percent and with intermodulation products better than 16 dB below carrier.

Whittaker, N.; Brassard, G.; Li, E.; Goux, P.

1990-01-01

234

Mobile Agents Based Collective Communication: An Application to a Parallel Plasma Simulation  

E-print Network

application. They can also benefit social ability and inter- actions of collaborative agents. Here we present benefit social ability and interactions of collaborative agents. Mobile Agents technology has been widelyMobile Agents Based Collective Communication: An Application to a Parallel Plasma Simulation

Vlad, Gregorio

235

GSM base stations: short-term effects on well-being.  

PubMed

The purpose of this study was to examine the effects of short-term GSM (Global System for Mobile Communications) cellular phone base station RF-EMF (radiofrequency electromagnetic fields) exposure on psychological symptoms (good mood, alertness, calmness) as measured by a standardized well-being questionnaire. Fifty-seven participants were selected and randomly assigned to one of three different exposure scenarios. Each of those scenarios subjected participants to five 50-min exposure sessions, with only the first four relevant for the study of psychological symptoms. Three exposure levels were created by shielding devices in a field laboratory, which could be installed or removed during the breaks between sessions such that double-blinded conditions prevailed. The overall median power flux densities were 5.2 microW/m(2) during "low," 153.6 microW/m(2) during "medium," and 2126.8 microW/m(2) during "high" exposure sessions. For scenario HM and MH, the first and third sessions were "low" exposure. The second session was "high" and the fourth was "medium" in scenario HM; and vice versa for scenario MH. Scenario LL had four successive "low" exposure sessions constituting the reference condition. Participants in scenarios HM and MH (high and medium exposure) were significantly calmer during those sessions than participants in scenario LL (low exposure throughout) (P = 0.042). However, no significant differences between exposure scenarios in the "good mood" or "alertness" factors were obtained. We conclude that short-term exposure to GSM base station signals may have an impact on well-being by reducing psychological arousal. PMID:18803247

Augner, Christoph; Florian, Matthias; Pauser, Gernot; Oberfeld, Gerd; Hacker, Gerhard W

2009-01-01

236

GSM Phase 2+ General Packet Radio Service GPRS: Architecture, Protocols, and Air Interface  

Microsoft Academic Search

The General Packet Radio Service (GPRS) is a new bearer service for GSM that greatly improves and simplifies wireless access to packet data networks, e.g., to the Internet. It applies a packet radio principle to transfer user data packets in an efficient way between mobile stations and external packet data networks. This tutorial gives an introduction to GPRS. The article

Christian Bettstetter; Hans-jörg Vögel; Jörg Eberspäche

1999-01-01

237

On the relaying capability of next-generation GSM cellular networks  

Microsoft Academic Search

The latest developments and experimentation in mobile ad hoc networks show that MANETs will be an alternative candidate in many private and public multimedia networks. Current interest in MANET systems has grown considerably because they can rapidly and economically extend the boundaries of any terrestrial network; integrating MANET and GSM offers a great number of benefits (e.g., increasing capacity, improving

George Neonakis Aggélou; Rahim Tafazolli

2001-01-01

238

GSM phase 2+ general packet radio service GPRS: Architecture, protocols, and air interface  

Microsoft Academic Search

The general packet radio service (GPRS) is a new bearer service for GSM that greatly improves and simplifies wireless access to packet data networks, e.g., to the Internet. It applies a packet radio principle to transfer user data packets in an efficient way between mobile stations and external packet data networks. This tutorial gives an introduction to GPRS. The article

Christian Bettstetter; Hans-Jorg Vogel; Jorg Eberspacher

1999-01-01

239

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

ERIC Educational Resources Information Center

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…

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

2008-01-01

240

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

E-print Network

1 Energy-Efficient Wireless Communication based on Directional Transmission from Mobile AccessSwitch dynamically select the best antenna during active wireless transceiving without disrupting the communication, the power amplifier (PA) is the most power-hungry component for wireless transmission. We aim

Zhong, Lin

241

Prediction of Fast Fading Mobile Radio Channels in Wideband Communication Systems  

E-print Network

Prediction of Fast Fading Mobile Radio Channels in Wideband Communication Systems Liang Dong on the performance of wireless communication systems, such that the prediction of the changing channel behaviors-frequency prediction scheme has superior performance over conducting the channel predic- tion on a single frequency. I

Dong, Liang

242

Maintaining A Free-Space-Optical Communication Link Between Two Autonomous Mobiles  

E-print Network

communication is prone to mobility. The highly directional FSO transceivers require establishment mechanical auto-tracking [7] or beam steering [8], and interference [9] and noise. Line- of-sight (LOS to not only deliver wireless communication links at optical-level speeds but also solve the wireless capacity

Yuksel, Murat

243

Mobile Communications for Medical Care a study of current and future healthcare and health promotion applications, and  

E-print Network

Mobile Communications for Medical Care a study of current and future healthcare and health Communications for Medical Care ­ Final Report 2 21 April 2011 #12;Mobile Communications for Medical Care a study of current and future healthcare and health promotion applications, and their use in China and elsewhere

Talbot, James P.

244

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

NASA Astrophysics Data System (ADS)

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.

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

1984-10-01

245

Maintaining Optimal Communication Chains in Robotic Sensor Networks using Mobility Control  

Microsoft Academic Search

This paper presents a decentralized mobility control algorithm for the formation and maintenance of an optimal cascaded communication\\u000a chain between a lead sensor-equipped robot and a control station, using a team of robotic vehicles acting as communication\\u000a relays in an unknown and dynamic RF environment. The gradient-based controller presented uses measurements of the signal-to-noise\\u000a ratio (SNR) field of neighbor communication

Cory Dixon; Eric W. Frew

2009-01-01

246

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

PubMed Central

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

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

2012-01-01

247

Network design consideration of a satellite-based mobile communications system  

NASA Technical Reports Server (NTRS)

Technical considerations for the Mobile Satellite Experiment (MSAT-X), the ground segment testbed for the low-cost spectral efficient satellite-based mobile communications technologies being developed for the 1990's, are discussed. The Network Management Center contains a flexible resource sharing algorithm, the Demand Assigned Multiple Access scheme, which partitions the satellite transponder bandwidth among voice, data, and request channels. Satellite use of multiple UHF beams permits frequency reuse. The backhaul communications and the Telemetry, Tracking and Control traffic are provided through a single full-coverage SHF beam. Mobile Terminals communicate with the satellite using UHF. All communications including SHF-SHF between Base Stations and/or Gateways, are routed through the satellite. Because MSAT-X is an experimental network, higher level network protocols (which are service-specific) will be developed only to test the operation of the lowest three levels, the physical, data link, and network layers.

Yan, T.-Y.

1986-01-01

248

Analyzing Cultural Usability of Mobile Keypad and Displays for Textual Communication in Internationalization and Localization Perspectives  

NASA Astrophysics Data System (ADS)

The aim of this paper is to identify the cultural usability aspects that need to be considered while internationalizing or localizing the interaction design of mobile keypads and displays for textual communication. The analysis is based primarily on heuristics tests, where: Hindi, Arabic and Danish mobile phones are evaluated based on assumptions of user needs, and in comparison to English. We have also referred the existing research on Chinese mobile phones to further complement our work. The study provides an insight into the much needed local-language centred approach in contrast with the current English centred approach of existing mobile keypad designs and display of text.

Orngreen, Rikke; Katre, Dinesh; Sandeep, Mulagapati

249

Mobility control load in future personal communication networks  

Microsoft Academic Search

Personal mobility is generally acknowledged as one of the key functions to be provided in future telecommunication networks. The processing load impact on the fixed infrastructure entities is expected to be heavy and have influence on manufactures and operators, due to its impact on respectively network architecture and dimensioning requirements. The paper applies a mobility model to the processing load

G. Colombo; L. De Martino; C. Eynard; L. Gabrielli

1993-01-01

250

An in vitro study of the effects of exposure to a GSM signal in two human cell lines: monocytic U937 and neuroblastoma SK-N-SH.  

PubMed

The use of mobile phones is increasing, which also increases the population's exposure to global system of mobile communications (GSM) signals. Questions of safety and possible biological effects are of concern and to date, remain largely unanswered. In order to examine possible biological effects of a GSM-like signal at a cellular level, we exposed two human cell lines (one of neuronal (SK-N-SH) and the other of monocytoid (U937) origin) to a 900 MHz RF signal, pulsed at 217 Hz, producing a specific absorption rate (SAR) of 0.2 W/kg. Putative effects were assessed by comparing radiofrequency-exposed cells to sham-exposed cells using a variety of assay techniques. For the cell line SK-N-SH, effects were specifically assessed by gene microarray, followed by real-time PCR of the genes of interest, Western blot analysis was used to measure heat shock protein levels, and flow cytometry to measure cell cycle distributions and apoptosis. Effects of radiofrequency on the cell line U937 were assessed by cell viability and cell cycle analysis. From our study of these two cell lines, we found no significant difference between sham-exposed versus radiofrequency-exposed cells in any of the assays or conditions examined. PMID:16877012

Gurisik, Ebru; Warton, Kristina; Martin, Donald K; Valenzuela, Stella M

2006-10-01

251

SNR-INDEPENDENT VELOCITY ESTIMATION FOR MOBILE CELLULAR COMMUNICATIONS SYSTEMS  

E-print Network

component of a mobile terminal's velocity has a linear relationship with the maximum Doppler frequency fm of a demodulated signal can also be used to estimate velocity, either directly 2], or using higher order statistics

Blostein, Steven D.

252

An operational open-end file transfer protocol for mobile satellite communications  

NASA Technical Reports Server (NTRS)

This paper describes an operational open-end file transfer protocol which includes the connecting procedure, data transfer, and relinquishment procedure for mobile satellite communications. The protocol makes use of the frame level and packet level formats of the X.25 standard for the data link layer and network layer, respectively. The structure of a testbed for experimental simulation of this protocol over a mobile fading channel is also introduced.

Wang, Charles; Cheng, Unjeng; Yan, Tsun-Yee

1988-01-01

253

Ad-Hoc Communication and Localization System for Mobile Robots  

NASA Astrophysics Data System (ADS)

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.

Neuwinger, Bernd; Witkowski, Ulf; Rückert, Ulrich

254

Mobile Communication in Romantic Relationships: Mobile Phone Use, Relational Uncertainty, Love, Commitment, and Attachment Styles  

Microsoft Academic Search

This study examines the associations between mobile phone use and relational uncertainty, love and commitment, and attachment styles. A survey of 197 college students revealed that greater use of mobile voice calls with a romantic partner was associated with lower relational uncertainty and more love and commitment. Also, the higher the avoidance, the less the participants used voice calls, and

Borae Jin; Jorge F. Peña

2010-01-01

255

Autonomous interactive intermediaries : social intelligence for mobile communication agents  

E-print Network

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 ...

Marti, Stefan Johannes Walter, 1965-

2005-01-01

256

Overview of NASA Glenn Aero/Mobile Communication Demonstrations  

NASA Technical Reports Server (NTRS)

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.

Brooks, David; Hoder, Doug; Wilkins, Ryan

2004-01-01

257

Overview of NASA Glenn Aero/Mobile Communications Demonstrations  

NASA Technical Reports Server (NTRS)

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.

Brooks, David; Hoder, Doug; Wilkins, Ryan

2004-01-01

258

Unsupervised User Similarity Mining in GSM Sensor Networks  

PubMed Central

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

Shad, Shafqat Ali; Chen, Enhong

2013-01-01

259

Outage Probability Performance in Mobile Indoor Optical Wireless Communication Environment  

E-print Network

placed on a mobile monitored patient and a base station located on the ceiling considering a one and ceiling reflections are taken into account so that the system is more accurately designed, even for low monitoring. The emitter is coupled with physiological sensors and placed on the patient. The base station

Paris-Sud XI, Université de

260

Efficient and secure keys management for wireless mobile communications  

Microsoft Academic Search

This paper presents an efficient algorithm for the secure group key management of mobile users. The most promising protocols to deal with group key management are those based on logical key hierarchy (LKH). The LKH model reduces to logarithmic size the resources needed: computation time, message exchanged, and memory space. In the framework of the LKH model, we present a

Roberto Di Pietro; Luigi V. Mancini; Sushil Jajodia

2002-01-01

261

Terrestrial mobile communication train measurements in western India  

Microsoft Academic Search

Mobile train radio measurements were conducted in the UHF band in western India with a total distance of 140 km utilizing eight track side base stations in different environments. The observed path losses deduced from signal levels were compared with those deduced from several prediction methods and their standard deviations are discussed. Path loss exponents are derived from signal levels

M. V. S. N. Prasad; Rajendra Singh

2003-01-01

262

Channel Modeling and Simulation in Satellite Mobile Communication Systems  

Microsoft Academic Search

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

Branka Vucetic; Jun Du

1992-01-01

263

Channel Simulation to Facilitate Mobile-Satellite Communications Research  

Microsoft Academic Search

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,

Faramaz Davarian

1987-01-01

264

Channel spacing in cellular FM mobile communication systems  

Microsoft Academic Search

This paper reports the results of a study considering channel spacing in a cellular FM mobile system. In the introduction, a short review of the subject is given and the essential quantities to be taken into account are outlined. Additionally some economic constraints will be considered. Following this, related propagation and laboratory experiments will be described. Then the relation between

B. Visser; K. Lalonde; G. Pomponi

1983-01-01

265

Network management convergence of multiple subnetworks in GSM infrastructure  

NASA Astrophysics Data System (ADS)

Network convergence, including service, timing and management convergence, is a trend of future telecommunication networks. Because network convergence can provide carriers with cost reduction, highly integrated applications as well as greater flexibility and functionality, new technologies and standards have driven this convergence tide. However, network management convergence, managing disparate networks with a unified platform, has been a challenging task in sophisticated telecommunication network environments. Administrators are faced with the task of managing various devices with several different applications, without an effective tool set to provide visibility across the network. In general, multiple transmission networks such as SDH, PON, HDSL and digital microwave are adopted in GSM infrastructure to transport mobile traffic between BTS and BSC. Traditional method of managing these devices is that GSM network (MSC, BSC and BTS), SDH, PON, HDSL and digital microwave are managed independently. In this paper, a converged network management platform, named OMConvergence, is proposed and demonstrated. The platform aims at managing the whole GSM network covering SDH, PON, HDSL or digital microwave sub-networks within it. The OMConvergence comprises of remote access methods of OAM message, as well as processing of multiple network management protocol such as ECC (Embedded Control Channel), Q3 and simple network management protocol (SNMP). The management and maintenance message of various devices physically converges to E1 timeslots at the sides of BTS, and then convert to unified IP packages before it is terminated at the side of BSC or network administration center. In addition, extended applications of OMConvergence in image monitoring of BTS surroundings are also demonstrated.

Zong, Baiqing; Su, Jiang; Zhong, Tao; Dong, Hui; Zhong, Shuangli; Zhou, Weiming; Chen, Wansheng

2001-10-01

266

Study of LEO-SAT microwave link for broad-band mobile satellite communication system  

NASA Technical Reports Server (NTRS)

In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented.

Fujise, Masayuki; Chujo, Wataru; Chiba, Isamu; Furuhama, Yoji; Kawabata, Kazuaki; Konishi, Yoshihiko

1993-01-01

267

A Communication Protocol to Improve Fairness and Data Amount on Sensor Data Collection with a Mobile Sink  

Microsoft Academic Search

Recently, many studies exploit mobile sinks to construct large-scale databases for environmental observations or weather forecasting. Mobile sinks travel in the sensing area that sensors are deployed, collect data from each sensor, and uploads them to sensor databases. By using mobile sinks, we can reduce communication traffic and maintenance cost compared with those for wireless sensor networks (WSNs). Some methods

Wataru Seino; Tomoki Yoshihisa; Takahiro Hara; Shojiro Nishio

2010-01-01

268

Abstract--Securing multicast communications in Mobile Ad Hoc Networks (MANET) is considered among the most challenging  

E-print Network

Abstract--Securing multicast communications in Mobile Ad Hoc Networks (MANET) is considered among the environment of study. I. INTRODUCTION Mobile Ad Hoc Network (MANET) is a collection of wireless mobile nodes realistic and fair comparison results that more accurately advocate the pros and cons of each protocol over

Baras, John S.

269

Increased Capacity Using CDMA for Mobile Satellite Communication  

Microsoft Academic Search

The performance of a spread-spectrum CDMA (code-division multiple access) system in a mobile satellite environment is analyzed. Comparisons to single-channel-per-carrier FDMA systems are presented which show that the CDMA approach provides greater capacity. Results from computer simulations, laboratory tests, and field tests of a prototype modem are also presented. The tests results show excellent performance of the modem in the

Klein S. Gilhousen; Irwin M. Jacobs; Roberto Padovani; Lindsay A. Weaver Jr.

1990-01-01

270

Development of superconductive microwave filters for mobile communications and filter banks  

Microsoft Academic Search

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

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

1999-01-01

271

Secure ICT Services for Mobile and Wireless Communications: A Federated Global Identity Management Framework  

Microsoft Academic Search

The paper reports on the current research activities related to the delivery of a federated global identity management framework for provisioning secure ICT services; this represents a significant step towards the development of global federated security services for the Web, grid and particularly for future mobile and wireless communication (ICT platforms). The overall aim of the research is to provide

Jawed I. A. Siddiqi; Babak Akhgar; Mehrdad Naderi; Wolfgang Orth; Norbert Meyer; Miika Tuisku; Gregor Pipan; Mario López Gallego; José Alberto García; Maurizio Cecchi; Jean-noel Colin

2006-01-01

272

Int. J. Emergency Management, Vol. 4, No. 4, 2007 649 Robust and affordable mobile communications for  

E-print Network

, Louisville KY 40292, USA E-mail: graham@louisville.edu James Gantt Center for Telecommunications Systems Management Murray State University 207 Industry and Technology Murray, KY 42071­3347, USA E-mail: james.gantt. and Gantt, J. (2007) `Robust and affordable mobile communications for emergency management', Int. J

Bowman, Michael

273

Enhancing Motivation in Online Courses with Mobile Communication Tool Support: A Comparative Study  

ERIC Educational Resources Information Center

Mobile technologies have helped establish new channels of communication among learners and instructors, potentially providing greater access to course information, and promoting easier access to course activities and learner motivation in online learning environments. The paper compares motivation between groups of learners being taught through an…

Chaiprasurt, Chantorn; Esichaikul, Vatcharaporn

2013-01-01

274

Ontology-Driven Information Retrieval System for Customers' Complaints of Mobile Communication Services  

Microsoft Academic Search

Ontology has been one of the hottest topic issues in artificial intelligence, knowledge engineering, especially in information process. In this paper, we propose an ontology-driven information retrieval (IR) system used for mining the interesting patterns in the domain of customers' complaints of mobile communication services. As the primary research of ontology model itself is about concept, properties of concept, relations

Ma Hui-nan; Wu Jiang-ning; Dang Yan-zhong

2006-01-01

275

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

Microsoft Academic Search

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.

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

276

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

Microsoft Academic Search

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

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

1991-01-01

277

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

Microsoft Academic Search

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

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

1991-01-01

278

An Implanted Spherical Head Model Exposed to Electromagnetic Fields at a Mobile Communication Frequency  

Microsoft Academic Search

Can cellular phones and personal communication systems base station antennas affect the active or passive implantable medical devices adversely? Concerns over the possible harmful effects of nonionizing irradiation upon implanted medical devices have been present for many years. Key issues to address are the questions of whether mobile phones have a detrimental effect on implants, and how the interaction of

S. M. S. Reyhani; Simone A. Ludwig

2006-01-01

279

Eye Contact Communication System between Mobile Robots Using Invisible Code Display  

E-print Network

Eye Contact Communication System between Mobile Robots Using Invisible Code Display Takeru Furukawa on displays which show an expression of robot's eyes. Keywords: 2D code, polarized invisible code, polarized light control, LCD display 1 Introduction "The eyes are eloquent as the tongue." This proverb means

Paris-Sud XI, Université de

280

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

ERIC Educational Resources Information Center

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…

Gary, Brett

1996-01-01

281

Efficient Mobile Communication Solutions for Remote Data Acquisition, Supervisory and Control Systems  

Microsoft Academic Search

Wireless technologies (mobile communications or other radiofrequency transmission methods) represent reliable and efficient solutions for remote data acquisition, supervisory and control systems. The correct selection of the proper transmission method from the wide variety of radio transmission methods and standards represents an important issue. For this reason in the firs part of this paper are presented briefly, the newest and

MARIANA JURIAN; IOAN LITA; DANIEL ALEXANDRU VISAN

2008-01-01

282

Intercarrier interference self-cancellation scheme for OFDM mobile communication systems  

Microsoft Academic Search

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

Yuping Zhao; Sven-Gustav Häggman

2001-01-01

283

Towards a Channel Allocation Scheme for SDMA-based Mobile Communication Systems  

Microsoft Academic Search

: Space Division Multiple Access (SDMA) is a new technology by whichthe capacity of existing cellular mobile communication systems can economically beincreased. Based on adaptive array antenna technology the spatial dimension of theexisting system is exploited by means of forming independent radio beams in each ofthe original channels. Operating SDMA, however, requires a suitable channel allocationscheme. In this paper we

Notker Gerlich; Michael Tangemann

1995-01-01

284

Network performance evaluations for Ku band mobile satellite communications system based on Shinkansen railroad's propagation conditions  

Microsoft Academic Search

This paper presents the network performance of our Ku band mobile satellite communications system under actual Shinkansen railroad propagation conditions. First, satellite visibility were judged by examining the obstacles obscuring the satellite in video taken by a small CCD camera with a fish-eye lens that was placed under the roof window of the Shinkansen High-Speed Multiple Inspection Train. After obtaining

Yutaka Imaizumi; Satoshi Harada; Fumiaki Nagase; Masayoshi Nakayama; Kohei Ohata; Masazumi Ueba

2005-01-01

285

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

Microsoft Academic Search

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

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

1994-01-01

286

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

ERIC Educational Resources Information Center

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…

Jones, Geraldine; Edwards, Gabriele; Reid, Alan

2009-01-01

287

Technological developments and socio-economic issues of wireless mobile communications  

Microsoft Academic Search

During the last 10 years, wireless communications can be considered as the fastest growing segment of telecommunications. In fact, mobile telephones have become an everyday accessory for hundreds of million people, and they are increasingly being used in the most developed and many developing countries in the world. Current forecasts indicate that demands for wireless access will exceed the number

Ronald Beaubrun; Samuel Pierre

2001-01-01

288

Joint multipath-Doppler diversity in mobile wireless communications  

Microsoft Academic Search

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

Akbar M. Sayeed; Behnaam Aazhang

1999-01-01

289

"Going Mobile" in Business Communication at an Arabian Gulf University  

ERIC Educational Resources Information Center

In this article, we describe a project in which undergraduate business seniors at a university in the Arabian Gulf created or evaluated the chapters of an iBook as part of their final course in business communication. Students were surveyed throughout the project, and they also participated in a focus group discussion at the end. The aim was to…

Rapanta, Chrysi; Nickerson, Catherine; Goby, Valerie Priscilla

2014-01-01

290

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

NASA Technical Reports Server (NTRS)

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.

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

1995-01-01

291

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

SciTech Connect

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.

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

2009-01-01

292

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

E-print Network

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

Grötschel, Martin

293

GSM Whitespaces: An Opportunity for Rural Cellular Service  

E-print Network

GSM Whitespaces: An Opportunity for Rural Cellular Service Shaddi Hasan, Kurtis Heimerl, Kate University of California, Berkeley Abstract--The GSM network is the largest network on Earth, providing vital financial and political cost of access to spectrum in GSM bands makes running a legal community cellular

California at Berkeley, University of

294

DETECTION AND BLANKING OF GSM INTERFERENCE IN RADIOASTRONOMICAL OBSERVATIONS  

E-print Network

DETECTION AND BLANKING OF GSM INTERFERENCE IN RADIO­ASTRONOMICAL OBSERVATIONS Amir Leshem * , Alle, satellite and broad­ cast services. In particular, the GSM band is a highly satu­ rated domain, full to radio astronomy, and the GSM sys­ tem which became ubiquitous and thus prevents observation in its band

Leshem, Amir

295

The security of the GSM air interface Chris J. Mitchell  

E-print Network

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

Dent, Alexander W.

296

Implementation of LSCMA adaptive array terminal for mobile satellite communications  

NASA Astrophysics Data System (ADS)

This paper considers the application of adaptive array antenna based on the least squares constant modulus algorithm (LSCMA) for interference rejection in mobile SATCOM terminals. A two-element adaptive array scheme is implemented with a combination of ADI TS201S DSP chips and Altera Stratix II FPGA device, which makes a cooperating computation for adaptive beamforming. Its interference suppressing performance is verified via Matlab simulations. Digital hardware system is implemented to execute the operations of LSCMA beamforming algorithm that is represented by an algorithm flowchart. The result of simulations and test indicate that this scheme can improve the anti-jamming performance of terminals.

Zhou, Shun; Wang, Huali; Xu, Zhijun

2007-11-01

297

An adaptive array antenna for mobile satellite communications  

NASA Technical Reports Server (NTRS)

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.

Milne, Robert

1990-01-01

298

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

Microsoft Academic Search

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

Rahul Amin; Kuang-Ching Wang; Parmesh Ramanathan

2007-01-01

299

Requirements for a mobile communications satellite system. Volume 2: Technical report  

NASA Technical Reports Server (NTRS)

Three types of satellite aided mobile communications are considered for users in areas not served by (terrestrial) cellular radio systems. In system 1, mobile units are provided a direct satellite link to a gateway station, which serves as the interface to the terrestrial toll network. In system 2, a terrestrial radio link similar to those in cellular systems connects the mobile unit to a translator station; each translator relays the traffic from mobile units in its vicinity, via satellite, to the regional gateway. It is not feasible for system 2 to provide obiquitous coverage. Therefore, system 3 is introduced, in which the small percentage of users not within range of a translator are provided a direct satellite link as in system 1.

Horstein, M.

1983-01-01

300

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

PubMed Central

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

Muthukumar, M.

2014-01-01

301

Future mobile satellite communication concepts at 20/30 GHz  

NASA Technical Reports Server (NTRS)

The outline of a design of a system using ultra small earth stations (picoterminals) for data traffic at 20/30 GHz is discussed. The picoterminals would be battery powered, have an RF transmitter power of 0.5 W, use a 10 cm square patch antenna, and have a receiver G/T of about -8 dB/K. Spread spectrum modulation would be required (due to interference consideration) to allow a telex type data link (less than 200 bit/s data rate) from the picoterminal to the hub station of the network and about 40 kbit/s on the outbound patch. An Olympus type transponder at 20/30 GHz could maintain several thousand simultaneous picoterminal circuits. The possibility of demonstrating a picoterminal network with voice traffic using Olympus is discussed together with fully mobile systems based on this concept.

Barton, S. K.; Norbury, J. R.

1990-01-01

302

Mobile Media Devices and Communication Applications as a Form of Augmentative and Alternative Communication: An Assessment of Family Wants, Needs, and Preferences  

E-print Network

This study assessed the wants, needs, and preferences of families at various stages of the decision-making process relative to mobile media technology as a form of augmentative and alternative communication (AAC). A survey entitled "iDevices, AAC...

Meder, Allison

2012-05-31

303

Towards efficient mobile M2M communications: survey and open challenges.  

PubMed

Machine-to-Machine (M2M) communications enable networked devices and services to exchange information and perform actions seamlessly without the need for human intervention. They are viewed as a key enabler of the Internet of Things (IoT) and ubiquitous applications, like mobile healthcare, telemetry, or intelligent transport systems. We survey existing work on mobile M2M communications, we identify open challenges that have a direct impact on performance and resource usage efficiency, especially the impact on energy efficiency, and we review techniques to improve communications. We review the ETSI standard and application protocols, and draw considerations on the impact of their use in constrained mobile devices. Nowadays, smartphones are equipped with a wide range of embedded sensors, with varied local and wide area connectivity capabilities, and thus they offer a unique opportunity to serve as mobile gateways for other more constrained devices with local connectivity. At the same time, they can gather context data about users and environment from the embedded sensors. These capabilities may be crucial for mobile M2M applications. Finally, in this paper, we consider a scenario where smartphones are used as gateways that collect and aggregate data from sensors in a cellular network. We conclude that, in order for their use to the feasible in terms of a normal depletion time of a smartphone's battery, it is a good advice to maximize the collection of data necessary to be transmitted from nearby sensors, and maximize the intervals between transmissions. More research is required to devise energy efficient transmission methods that enable the use of smartphones as mobile gateways. PMID:25333291

Pereira, Carlos; Aguiar, Ana

2014-01-01

304

Measured performance of GSM, HSCSD and GPRS  

Microsoft Academic Search

In this paper we present results of measurements on the performance of GSM HSCSD and GPRS data transmission. We used a measurement tool that we have developed to study the performance of various wireless links as perceived by nomadic applications using TCP. The results show that in stationary connections the throughput and response time are stable and, in general, close

Jouni Korhonen; Olli Aalto; Andrei Gurtov; Heimo Laamanen

2001-01-01

305

Current evolution of the GSM systems  

Microsoft Academic Search

The central topic of the article is the past, present and future evolution of the technical aspects of the GSM system and its derivatives such as DCS 1800 and DCS 1900, as viewed from the European standardization bodies. An important part of the article outlines the current evolution, trying to identify the major trends that are likely to show where

M. Mouly; M.-B. Pautet

1995-01-01

306

Exposure setup to study potential adverse effects at GSM 1800 and UMTS frequencies on the auditory systems of rats.  

PubMed

To investigate possible biological effects of exposure to electromagnetic (EM) fields at the frequencies of global system for mobile communication (GSM) 1800 system and universal mobile telecommunication system (UMTS) on the auditory system of rats, an exposure setup for in vivo experiments is presented. The study was carried out in the framework of two European research projects. The target of the investigation was the cochlea. A dosimetric study was performed, both numerically and through direct measurements, to assess the interaction of the radiated fields and the dose distribution in the biological target. For the local exposure of rats, a loop antenna operating at the frequency bands of interest was designed, realised and characterised through numerical and experimental dosimetric procedures. Moreover, an exposure apparatus was set up, consisting of three arrays of four loop antennas, placed on three levels, thus allowing simultaneous exposure of 12 rats to give statistical power to the experiments. To isolate the exposure arrays, the setup was assembled by a wooden rack with EM field absorbing panels, inserted among the levels and at the four sides of the rack. Isolation was verified by direct measurements. Two exposure arrays were simultaneously supplied, whereas the third one was used for sham exposure. Blind exposure was achieved through a black box, hiding physical connections to the microwave power supply. During exposure sessions, rats were restrained in special plastic jigs for repeatable positioning, thus assuring the fixed level of dose in the target. PMID:17164273

Lopresto, V; Pinto, R; De Vita, A; Mancini, S; Galloni, P; Marino, C; Ravazzani, P; Lovisolo, G A

2007-01-01

307

Performance Evaluation of Mobile Ad Hoc Network Based Communications for Future Mobile Tele-Emergency System  

NASA Astrophysics Data System (ADS)

Sparked by awareness of the limitations to provide medical services in remote areas, researchers have perceived that developing telemedicine systems is inevitable. In most cases very remote areas and disaster struck areas lack telecommunication infrastructure. Telemedicine system operating in such areas must have advanced wireless technology supporting it in devastating situation, hence it is called as tele-emergency system. Our approach is on MANET combined with Mobile IP and MIPV6, is the basis of infrastructure for the mobile tele-emergency system. The tele-emergency system requires data, voice and video transmission in its network. In this investigation, evaluation is based on simulation of the various ITU-T standard CODECs of VoIP and video transmission over MANET using discrete event simulator NS-2. The results of simulation showed that ITU-T G723.1 worked well in the MANET environment than the other CODECs for VoIP in fixed and mobility tele-emergency environments. From the simulation of video CODEC performance evaluation, it was observed that H.263 performed to a great extent in random small scale environment and also in multiple video flow of 57.6kbps speed video transmission.

Viswacheda, D. V.; Barukang, L.; Hamid, M. Y.; Arifianto, M. S.

308

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

NASA Technical Reports Server (NTRS)

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.

1989-01-01

309

Issues for the integration of satellite and terrestrial cellular networks for mobile communications  

NASA Technical Reports Server (NTRS)

Satellite and terrestrial cellular systems naturally complement each other for land mobile communications, even though present systems have been developed independently. The main advantages of the integrated system are a faster wide area coverage, a better management of overloading traffic conditions, an extension to geographical areas not covered by the terrestrial network and, in perspective, the provision of only one integrated system for all mobile communications (land, aeronautical, and maritime). To achieve these goals, as far as possible the same protocols of the terrestrial network should be used also for the satellite network. Discussed here are the main issues arising from the requirements of the main integrated system. Some results are illustrated, and possible future improvements due to technical solutions are presented.

Delre, Enrico; Mistretta, Ignazio; Dellipriscoli, Francesco; Settimo, Franco

1991-01-01

310

An advanced conceptual design study for a mobile satellite communications system  

NASA Astrophysics Data System (ADS)

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.

Salmasi, A. B.

311

Wimax - Potential Commercial Off-The-Shelf Solution for Tactical Mobile Mesh Communications  

Microsoft Academic Search

The Army is evaluating the capabilities' of emerging technologies based on the IEEE 802.16 standard as a potential commercial off-the-shelf solution to support the communication requirements of the future warfighter. This paper evaluates the mesh mode defined in the IEEE 802.16d (fixed WiMax) standard to determine if it is technically feasible for WiMax to support mobile mesh networking by proposing

M. B. K. Hartzog; Timothy X Brown

2006-01-01

312

Mobile and Personal Communications in the 60 GHz Band: A Survey  

Microsoft Academic Search

This paper intends to present a summary of the technical issues arising in the exploitation of the 60 GHz mm-wave band for mobile and personal communications. The most significant applications proposed so far are surveyed, with particular emphasis placed on recent experimentation about millimeter-wave propagation for road\\/railway transportation as well as indoor scenarios. As a case study, the capacity of

Filippo Giannetti; Marco Luise; Ruggero Reggiannini

1999-01-01

313

Tantalisingly Close: An Archaeology of Communication Desires in Discourses of Mobile Wireless Media  

Microsoft Academic Search

While many studies on mobile wireless communication devices predominantly take a micro-scale approach and concentrate their often ethnographically informed focus on use values, social implications, conversation strategies, changing norms and ethics, culture-dependent domestication, and so forth, with this Ph.D. dissertation I propose to venture into a more historical and comparative direction, mainly in order to shed light on and engage

I. O. de Vries

2008-01-01

314

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

Microsoft Academic Search

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

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

1990-01-01

315

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

Microsoft Academic Search

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

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

1988-01-01

316

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

Microsoft Academic Search

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

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

2005-01-01

317

Power-efficient directional wireless communication on small form-factor mobile devices  

Microsoft Academic Search

Wireless access is known to be power-hungry for mobile devices. A key reason is that devices radiate power in all directions and much of this power will not reach the destination. To address this waste, we present BeamSwitch, a multi-antenna system designed to realize directional communication efficiently. Unlike power-hungry and expensive beamforming, BeamSwitch requires only one transceiver. We provide an

Ardalan Amiri Sani; Hasan Dumanli; Lin Zhong; Ashutosh Sabharwal

2010-01-01

318

An integrated Ka/Ku-band payload for personal, mobile and private business communications  

NASA Astrophysics Data System (ADS)

The Canadian Department of Communications has been studying options for a government-sponsored demonstration payload to be launched before the end of the century. A summary of the proposed system concepts and network architectures for providing an advanced private business network service at Ku-band and personal and mobile communications at Ka-band is presented. The system aspects addressed include coverage patterns, traffic capacity, and grade of service, multiple access options as well as special problems, such as Doppler in mobile applications. Earth terminal types and the advanced payload concept proposed in a feasibility study for the demonstration mission are described. This concept is a combined Ka-band/Ku-band payload which incorporates a number of advanced satellite technologies including a group demodulator to convert single-channel-per-carrier frequency division multiple access uplink signals to a time division multiplex downlink, on-board signal regeneration, and baseband switching to support packet switched data operation. The on-board processing capability of the payload provides a hubless VSAT architecture which permits single-hop full mesh interconnectivity. The Ka-band and Ku-band portions of the payload are fully integrated through an on-board switch, thereby providing the capability for fully integrated services, such as using the Ku-band VSAT terminals as gateway stations for the Ka-band personal and mobile communications services.

Hayes, Edward J.; Keelty, J. Malcolm

1991-09-01

319

Satellite-aided mobile communications limited operational test in the trucking industry  

NASA Technical Reports Server (NTRS)

An experiment with NASA's ATS-6 satellite, that demonstrates the practicality of satellite-aided land mobile communications is described. Satellite communications equipment for the experiment was designed so that it would be no more expensive, when mass produced, than conventional two-way mobile radio equipment. It embodied the operational features and convenience of present day mobile radios. Vehicle antennas 75 cm tall and 2 cm in diameter provided good commercial quality signals to and from trucks and jeeps. Operational applicability and usage data were gathered by installing the radio equipment in five long-haul tractor-trailer trucks and two Air Force search and rescue jeeps. Channel occupancy rates are reported. Air Force personnel found the satellite radio system extremely valuable in their search and rescue mission during maneuvers and actual rescue operations. Propagation data is subjectively analyzed and over 4 hours of random data is categorized and graded as to signal quality on a second by second basis. Trends in different topographic regions are reported. An overall communications reliability of 93% was observed despite low satellite elevation angles ranging from 9 to 24 degrees.

Anderson, R. E.; Frey, R. L.; Lewis, J. R.

1980-01-01

320

Analysis of network traffic in ad-hoc networks based on DSDV protocol with emphasis on mobility and communication patterns  

Microsoft Academic Search

An ad-hoc network is a collection of mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. Because of the limited communication range among mobile nodes in ad-hoc networks, several network hops may be needed to deliver a packet from one node to another one in the wireless network. In recent years,

V. Garousi

2005-01-01

321

PAULRAJ, GESBERT, PAPADIAS, ENCYCLOPEDIA FOR ELECTRICAL ENGINEERING, JOHN WILEY PUBLISHING CO., 2000 1 Smart Antennas for Mobile Communications  

E-print Network

., 2000 1 Smart Antennas for Mobile Communications A. J. Paulraj, D. Gesbert, C. Papadias Abstract--This paper presents a tutorial on emerging tech- nologies in the area of Smart Antennas for mobile wireless performance of the network. Smart antennas systems use modems which combine the signals of multi

Gesbert, David

322

Measurement of EM Field Inside a Cruising Aircraft: Potential Problems for the Use of Mobile Phones on Board  

NASA Astrophysics Data System (ADS)

Electromagnetic (EM) emissions from portable electronic devices (PEDs) carried onboard aircraft can interfere with avionic systems. Several onboard systems using EM waves have been planned, such as mobile communications and UWB (ultra-wideband) entertainment services distribution. Manufacturers of this system develop schemes to avoid electromagnetic interference by the transmissions (emissions) of mobile phones with avionic systems; some local-specific problems still remain. The purpose of this chapter is to investigate to what extent non-GSM transmissions from the ground base stations reach inside a cruising aircraft. The EM field at the base station frequency bands is measured in a cruising small aircraft.

Kohmura, A.; Picard, J.; Yonemoto, N.; Yamamoto, K.

323

Overview of GSM: Philosophy and results  

Microsoft Academic Search

The work on GSM, a standardized European second-generation cellular system, was started in 1982 in order to prevent the fragmentation of the first-generation cellular market from continuing into the second generation. The goal was to define a system with open interfaces for Pan-European use that would offer the best compromise between a number of conflicting requirements, such as spectrum economy,

Thomas Haug

1994-01-01

324

OBCOM2006 INT'L CONFERENCE ON MOBILE, UBIQUITOUS & PERVASIVE COMPUTING Information and Communication Technologies (ICT) are critical to  

E-print Network

and Communication Technologies (ICT) are critical to India's future and underpin realization of the Vision 2020. It is essential that ICT sector meet the rise in demand for health and social care and to modernize services. In this context, use of mobile computing and communication is the key success factor for us in the global race

Melbourne, University of

325

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

Code of Federal Regulations, 2012 CFR

... 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...

2012-01-01

326

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

Code of Federal Regulations, 2013 CFR

... 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...

2013-01-01

327

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

Code of Federal Regulations, 2014 CFR

... 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...

2014-01-01

328

Effects of exposure of the ear to GSM microwaves: in vivo and in vitro experimental studies.  

PubMed

The effects of mobile phone (GSM) microwaves on the ears of guinea pigs were investigated in two in vivo experiments and one in vitro experiment. In the first experiment, three groups of eight guinea pigs had their left ear exposed for 1 h/day, 5 days/week, for 2 months, to GSM microwaves (900 MHz. GSM modulated) at specific absorption rates (SARs) of 1, 2 and 4 W/kg respectively, and a fourth group was sham-exposed. Distortion-product otoacoustic emissions (DPOAEs) were measured for each ear before exposure, at the end of the 2-month exposure period, and 2 months later. In the second experiment, the same protocol was applied to eight sham-exposed and 16 exposed guinea pigs at 4W/kg, but the auditory brainstem response (ABR) thresholds were monitored. Repeated-measures ANOVA showed no difference in DPOAE amplitudes or in ABR thresholds between the exposed and non-exposed ears and between the sham-exposed and exposed groups In the course of the second experiment, acute effects were also investigated by measuring once, in all animals, ABR thresholds just before and just after the 1-h exposure: no statistically significant difference was observed. In vitro, the two organs of Corti (OCs) of newborn rats (n=15) were isolated and placed in culture. For each animal, one OC was exposed for 24-48 h to 1 W/kg GSM microwaves, and the other was sham-exposed. After 2-3 days of culture, all OCs were observed under light microscopy. They all appeared normal to naive observers at this stage of development. These results provided no evidence that microwave radiation, at the levels produced by mobile phones, caused damage to the inner ear or the auditory pathways in our experimental animals. PMID:15726845

Aran, Jean-Marie; Carrere, Nathalie; Chalan, Yan; Dulou, Pierre-Emmanuel; Larrieu, Sophie; Letenneur, Luc; Veyret, Bernard; Dulon, Didier

2004-10-01

329

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

E-print Network

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

Wetzel, Susanne

330

Short-term exposure to mobile phone base station signals does not affect cognitive functioning or physiological measures in individuals who report sensitivity to electromagnetic fields and controls.  

PubMed

Individuals who report sensitivity to electromagnetic fields often report cognitive impairments that they believe are due to exposure to mobile phone technology. Previous research in this area has revealed mixed results, however, with the majority of research only testing control individuals. Two studies using control and self-reported sensitive participants found inconsistent effects of mobile phone base stations on cognitive functioning. The aim of the present study was to clarify whether short-term (50 min) exposure at 10 mW/m(2) to typical Global System for Mobile Communication (GSM) and Universal Mobile Telecommunications System (UMTS) base station signals affects attention, memory, and physiological endpoints in sensitive and control participants. Data from 44 sensitive and 44 matched-control participants who performed the digit symbol substitution task (DSST), digit span task (DS), and a mental arithmetic task (MA), while being exposed to GSM, UMTS, and sham signals under double-blind conditions were analyzed. Overall, cognitive functioning was not affected by short-term exposure to either GSM or UMTS signals in the current study. Nor did exposure affect the physiological measurements of blood volume pulse (BVP), heart rate (HR), and skin conductance (SC) that were taken while participants performed the cognitive tasks. PMID:19475647

Eltiti, Stacy; Wallace, Denise; Ridgewell, Anna; Zougkou, Konstantina; Russo, Riccardo; Sepulveda, Francisco; Fox, Elaine

2009-10-01

331

Interference Analysis Status and Plans for Aeronautical Mobile Airport Communications System (AeroMACS)  

NASA Technical Reports Server (NTRS)

Interference issues related to the operation of an aeronautical mobile airport communications system (AeroMACS) in the C-Band (specifically 5091-5150 MHz) is being investigated. The issue of primary interest is co-channel interference from AeroMACS into mobile-satellite system (MSS) feeder uplinks. The effort is focusing on establishing practical limits on AeroMACS transmissions from airports so that the threshold of interference into MSS is not exceeded. The analyses are being performed with the software package Visualyse Professional, developed by Transfinite Systems Limited. Results with omni-directional antennas and plans to extend the models to represent AeroMACS more accurately will be presented. These models should enable realistic analyses of emerging AeroMACS designs to be developed from NASA Test Bed, RTCA 223, and European results.

Kerczewski, Robert J.; Wilson, Jeffrey D.

2010-01-01

332

Using a Communication Model to Collect Measurement Data through Mobile Devices  

PubMed Central

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

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

2012-01-01

333

Statistically validated mobile communication networks: the evolution of motifs in European and Chinese data  

NASA Astrophysics Data System (ADS)

Big data open up unprecedented opportunities for investigating complex systems, including society. In particular, communication data serve as major sources for computational social sciences, but they have to be cleaned and filtered as they may contain spurious information due to recording errors as well as interactions, like commercial and marketing activities, not directly related to the social network. The network constructed from communication data can only be considered as a proxy for the network of social relationships. Here we apply a systematic method, based on multiple-hypothesis testing, to statistically validate the links and then construct the corresponding Bonferroni network, generalized to the directed case. We study two large datasets of mobile phone records, one from Europe and the other from China. For both datasets we compare the raw data networks with the corresponding Bonferroni networks and point out significant differences in the structures and in the basic network measures. We show evidence that the Bonferroni network provides a better proxy for the network of social interactions than the original one. Using the filtered networks, we investigated the statistics and temporal evolution of small directed 3-motifs and concluded that closed communication triads have a formation time scale, which is quite fast and typically intraday. We also find that open communication triads preferentially evolve into other open triads with a higher fraction of reciprocated calls. These stylized facts were observed for both datasets.

Li, Ming-Xia; Palchykov, Vasyl; Jiang, Zhi-Qiang; Kaski, Kimmo; Kertész, János; Miccichè, Salvatore; Tumminello, Michele; Zhou, Wei-Xing; Mantegna, Rosario N.

2014-08-01

334

Practical Metropolitan-Scale Positioning for GSM Phones  

Microsoft Academic Search

This paper examines the positioning accuracy of a GSM beacon- based location system in a metropolitan environment. We explore five factors effecting positioning accuracy: location algorithm choice, scan set size, simultaneous use of cells from different providers, training and testing on different devices, and calibration data density. We collected a 208-hour, 4350Km driving trace of three different GSM networks covering

Mike Y. Chen; Timothy Sohn; Dmitri Chmelev; Dirk Haehnel; Jeffrey Hightower; Jeff Hughes; Anthony Lamarca; Fred Potter; Ian E. Smith; Alex Varshavsky

2006-01-01

335

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

NASA Technical Reports Server (NTRS)

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.

Castiel, David

1991-01-01

336

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

PubMed

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

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

2015-01-01

337

Place-Based Attributes Predict Community Membership in a Mobile Phone Communication Network  

PubMed Central

Social networks can be organized into communities of closely connected nodes, a property known as modularity. Because diseases, information, and behaviors spread faster within communities than between communities, understanding modularity has broad implications for public policy, epidemiology and the social sciences. Explanations for community formation in social networks often incorporate the attributes of individual people, such as gender, ethnicity or shared activities. High modularity is also a property of large-scale social networks, where each node represents a population of individuals at a location, such as call flow between mobile phone towers. However, whether or not place-based attributes, including land cover and economic activity, can predict community membership for network nodes in large-scale networks remains unknown. We describe the pattern of modularity in a mobile phone communication network in the Dominican Republic, and use a linear discriminant analysis (LDA) to determine whether geographic context can explain community membership. Our results demonstrate that place-based attributes, including sugar cane production, urbanization, distance to the nearest airport, and wealth, correctly predicted community membership for over 70% of mobile phone towers. We observed a strongly positive correlation (r?=?0.97) between the modularity score and the predictive ability of the LDA, suggesting that place-based attributes can accurately represent the processes driving modularity. In the absence of social network data, the methods we present can be used to predict community membership over large scales using solely place-based attributes. PMID:23451034

Caughlin, T. Trevor; Ruktanonchai, Nick; Acevedo, Miguel A.; Lopiano, Kenneth K.; Prosper, Olivia; Eagle, Nathan; Tatem, Andrew J.

2013-01-01

338

Channel aware HARQ scheme based on LDPC codes for land mobile satellite communication system  

NASA Astrophysics Data System (ADS)

In this paper, a channel aware HARQ (CA-HARQ) scheme based on data punctured rate compatible LDPC (DP-LDPC) codes, which might satisfy the demand for bandwidth and rate in land mobile communication system, is proposed. The scheme is based on type II HARQ technique cooperated with a DP- LDPC code. In the proposed scheme, the effective rate of the LDPC code is adapted according to the channel quality information (CQI) estimated at the receiver, so as to decrease the redundancy when the channel is good and vice versa, the retransmitted blocks are combined with the previous information transmitted to achieve high probability of successful decoding. In this paper, we use a 2-bit CQI feedback scheme. Simulation results, which based on a land mobile satellite channel, show that the proposed channel aware H-ARQ scheme based on DP-LDPC codes improved the throughput by 0.4dB at low SNR compared to a pure DP-LDPC type II HARQ, and it can also be an effective solution to compensate rain attenuation and multipath fading in land mobile satellite systems.

Yang, Yongli; Zhu, Guangxi; Wang, Desheng; Wu, Lifen

2007-11-01

339

Structured P2P Overlay of Mobile Brokers for Realizing Publish/Subscribe Communication in VANET  

PubMed Central

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

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

2014-01-01

340

Technical characteristics of the OmniTRACS: The first operation mobile Ku-band satellite communications system  

NASA Technical Reports Server (NTRS)

The techinical characteristics of the OmniTRACS system are described. The system is the first operational mobile Ku-band satellite communications system and provides two-way message and position determination service to mobile terminals using existing Ku-band satellites. Interference to and from the system is minimized by the use of special spread-spectrum techniques, together with low power and low data rate transmissions.

Antonio, Franklin P.; Gilhousen, Klein S.; Jacobs, Irwin M.; Weaver, Linday A., Jr.

1988-01-01

341

GSM base-station antenna diversity using soft decision combining on up-link and delayed-signal transmission on down-link  

Microsoft Academic Search

Two branch base-station antenna diversity performance for the GSM (Groupe Speciale Mobile) system is simulated. For the uplink combining, soft decision signals from two SOVA data-detectors are used for a (nearly) optimum post-detection combining. For downlink, a delayed-signal (on the order of 2-b periods) is transmitted on a second antenna branch in order to introduce \\

P. E. Morgensen

1993-01-01

342

FDTD based SAR analysis in human head using irregular volume averaging techniques of different resolutions at GSM 900 band  

NASA Astrophysics Data System (ADS)

Specific absorption rate (SAR) induced inside human head in the near-field of a mobile phone antenna has been investigated for three different SAR resolutions using Finite Difference in Time Domain (FDTD) method at GSM 900 band. Voxel based anthropomorphic human head model, consisting of different anatomical tissues, is used to calculate the peak SAR values averaged over 10-g, 1-g and 0.1-g mass. It is observed that the maximum local SAR increases significantly for smaller mass averages.

Ali, Md Faruk; Ray, Sudhabindu

2014-06-01

343

The design and networking of dynamic satellite constellations for global mobile communication systems  

NASA Technical Reports Server (NTRS)

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.

Cullen, Cionaith J.; Benedicto, Xavier; Tafazolli, Rahim; Evans, Barry

1993-01-01

344

Enhanced spectral efficiency using bandwidth switchable SAW filtering for mobile satellite communications systems  

NASA Technical Reports Server (NTRS)

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.

Peach, Robert; Malarky, Alastair

1990-01-01

345

Concepts and cost trade-offs for land vehicle antennas in satellite mobile communications  

NASA Technical Reports Server (NTRS)

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.

Haddad, H. A.

1948-01-01

346

SUPL support for mobile devices  

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

347

Development of novel microstrip antennas for use in mobile and wireless communication systems at Jadavpur University in the present decade  

Microsoft Academic Search

Microstrip technology has received special importance in the domain of mobile and wireless communications because of its numerous advantages like small size, light weight, polarization versatility and others. However, it still suffers from limitations in terms of several useful parameters like band width, power handling capacity etc. Researches at Jadavpur University by the authors focussed on improving the technology throughout

Samik Chakraborty; Bhaskar Gupta

2007-01-01

348

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

E-print Network

band frequency channel quality 1 2 3 4 5 6 narrow band signal guard space narrowband channels due;Edgar Nett Mobile Computer Communication SS'14 25 FHSS (Frequency Hopping Spread Spectrum) I Discrete changes of carrier frequency (hopping) q Hopping sequence determined via pseudo random number sequence Two

349

GSM. Columbia Plateau Geologic Site Simulation  

SciTech Connect

GSM is a Monte Carlo simulation program for tracking the future evolution of a repository site over periods of up to several million years. Phenomena included in the model that potentially can affect the site over such periods are: climatic changes, glaciation, deformation, geomorphic events, magmatic events, meteorite impact, sea-level fluctuations, shaft seal failure, basement faulting, and undetected features. Interrelationships among phenomena are modeled, and the effects of changes on ground-water flow are followed using a simplified network model of the ground-water system in a two-dimensional cross-section of the study area. The model is specific to a potential repository site in the Pasco Basin area of the Columbia Plateau. The ground water portion of the code is two-dimensional and is based on a specific conceptualization of the hydrology in the region surrounding the Pasco Basin. The probabilistic nature of the model enables it to be used to evaluate whether a potential site meets any probabilistic regulatory standards such as those that have been issued by the Environmental Protection Agency. Two auxiliary interactive programs to process input and output, respectively, are included. The Input Module is executed prior to the simulation to 1) generate a set of unformatted data files for first-time simulation access; 2) change any or all input parameter values from the previous simulation; or 3) generate listings of input parameter values. The Output Module is used to examine the three unformatted files (SUMMARY, HISTORY, and MASTER) produced by GSM. In addition, an auxiliary conversion routine is included to convert the formatted climate data to binary records for use by the Far Field State Model (FFSM) program .

Golis, M.J. [Battelle Columbus Division, OH (United States)

1984-06-01

350

Feasibility and usability of a home monitoring concept based on mobile phones and near field communication (NFC) technology.  

PubMed

Utilization of mobile information and communication technologies in home monitoring applications is becoming more and more common. The mobile phone, acting as a patient terminal for patients suffering from chronic diseases, provides an active link to the caregiver to transmit health status information and receive feedback. In such a concept the usability is still limited by the necessity of entering the values via the mobile phone's small keypad. The near field communication technology (NFC), a touch-based wireless interface that became available recently, may improve the usability level of such applications significantly. The focus of this paper is to describe the development of a prototype application based on this technology embedded in a home monitoring system. The feasibility and usability of this approach are evaluated and compared with concepts used in previous approaches. The high quantifier with respect to overall usability indicates that NFC may be the technology of choice for some tasks in home monitoring applications. PMID:17911689

Morak, Jürgen; Kollmann, Alexander; Schreier, Günter

2007-01-01

351

7 CFR 1488.22 - Communications.  

Code of Federal Regulations, 2012 CFR

...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...

2012-01-01

352

7 CFR 1488.22 - Communications.  

Code of Federal Regulations, 2014 CFR

...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...

2014-01-01

353

7 CFR 1488.22 - Communications.  

Code of Federal Regulations, 2013 CFR

...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...

2013-01-01

354

Satellite applications to electric-utility communications needs. [land mobile satellite service  

NASA Technical Reports Server (NTRS)

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.

Horstein, M.; Barnett, R.

1981-01-01

355

Adaptive data rate SSMA system for personal and mobile satellite communications  

NASA Technical Reports Server (NTRS)

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.

Ikegami, Tetsushi; Takahashi, Takashi; Arakaki, Yoshiya; Wakana, Hiromitsu

1995-01-01

356

The role of interpersonal communication in the process of knowledge mobilization within a community-based organization: a network analysis  

PubMed Central

Background Diffusion of innovations theory has been widely used to explain knowledge mobilization of research findings. This theory posits that individuals who are more interpersonally connected within an organization may be more likely to adopt an innovation (e.g., research evidence) than individuals who are less interconnected. Research examining this tenet of diffusion of innovations theory in the knowledge mobilization literature is limited. The purpose of the present study was to use network analysis to examine the role of interpersonal communication in the adoption and mobilization of the physical activity guidelines for people with spinal cord injury (SCI) among staff in a community-based organization (CBO). Methods The study used a cross-sectional, whole-network design. In total, 56 staff completed the network survey. Adoption of the guidelines was assessed using Rogers’ innovation-decision process and interpersonal communication was assessed using an online network instrument. Results The patterns of densities observed within the network were indicative of a core-periphery structure revealing that interpersonal communication was greater within the core than between the core and periphery and within the periphery. Membership in the core, as opposed to membership in the periphery, was associated with greater knowledge of the evidence-based physical activity resources available and engagement in physical activity promotion behaviours (ps?communication is associated with knowledge mobilization and highlight how the network structure could be improved for further dissemination efforts. Keywords: diffusion of innovations; network analysis; community-based organization; knowledge mobilization; knowledge translation, interpersonal communication. PMID:24886429

2014-01-01

357

Single antenna interference cancellation in asynchronous GSM/GPRS networks  

E-print Network

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 ...

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

2005-01-01

358

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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:...

2011-09-19

359

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

Federal Register 2010, 2011, 2012, 2013, 2014

...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:...

2011-07-27

360

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

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

Vouyioukas, Demosthenes

361

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)

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.

Wilcox, R. E.

1985-01-01

362

Enhanced Services for World-Wide Web in Mobile WAN Environment  

Microsoft Academic Search

Currently, the World-Wide Web (WWW) is the best-known and most widely used distributed multimedia application. By utilising the data services of a cellular telephone system, for example the digital GSM system, WWW can be brought to nomadic users. The advantage of using an existing cellular network like the GSM is that it takes care of terminal mobility, including location updates

Mika Liljeberg; Heikki Helin; Markku Kojo; Kimmo Raatikainen

1996-01-01

363

Energy consumption in mobile phones: a measurement study and implications for network applications  

Microsoft Academic Search

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

Niranjan Balasubramanian; Aruna Balasubramanian; Arun Venkataramani

2009-01-01

364

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

Microsoft Academic Search

A new Cloud Mobile Gaming (CMG) approach, where the responsibility of executing the gaming engines, including the most compute intensive tasks of graphic rendering, is put on cloud servers instead of the mobile devices, has the potential for enabling mobile users to play the same rich Internet games available to PC users. However, the mobile gaming user experience may be

Shaoxuan Wang; Sujit Dey

2010-01-01

365

Differential signaling spread-spectrum modulation of the LED visible light wireless communications using a mobile-phone camera  

NASA Astrophysics Data System (ADS)

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.

Chen, Shih-Hao; Chow, Chi-Wai

2015-02-01

366

R&D of a Next Generation LEO System for Global Multimedia Mobile Satellite Communications  

NASA Astrophysics Data System (ADS)

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

Morikawa, E.; Motoyoshi, S.; Koyama, Y.; Suzuki, R.; Yasuda, Y.

2002-01-01

367

Low-mobility channel tracking for MIMO-OFDM communication systems  

NASA Astrophysics Data System (ADS)

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.

Pagadarai, Srikanth; Wyglinski, Alexander M.; Anderson, Christopher R.

2013-12-01

368

Requirements for a mobile communications satellite system. Volume 3: Large space structures measurements study  

NASA Technical Reports Server (NTRS)

This study report defines a set of tests and measurements required to characterize the performance of a Large Space System (LSS), and to scale this data to other LSS satellites. Requirements from the Mobile Communication Satellite (MSAT) configurations derived in the parent study were used. MSAT utilizes a large, mesh deployable antenna, and encompasses a significant range of LSS technology issues in the areas of structural/dynamics, control, and performance predictability. In this study, performance requirements were developed for the antenna. Special emphasis was placed on antenna surface accuracy, and pointing stability. Instrumentation and measurement systems, applicable to LSS, were selected from existing or on-going technology developments. Laser ranging and angulation systems, presently in breadboard status, form the backbone of the measurements. Following this, a set of ground, STS, and GEO-operational were investigated. A third scale (15 meter) antenna system as selected for ground characterization followed by STS flight technology development. This selection ensures analytical scaling from ground-to-orbit, and size scaling. Other benefits are cost and ability to perform reasonable ground tests. Detail costing of the various tests and measurement systems were derived and are included in the report.

Akle, W.

1983-01-01

369

Performance of the unique-word-reverse-modulation type demodulator for mobile satellite communications  

NASA Technical Reports Server (NTRS)

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).

Dohi, Tomohiro; Nitta, Kazumasa; Ueda, Takashi

1993-01-01

370

Adaptive MIMO-MLSE Blind Detection in Heterogeneous Stream Transmission for Mobile Radio Communications  

NASA Astrophysics Data System (ADS)

This paper proposes a novel MIMO system that introduces a heterogeneous stream (HTS) scheme and a blind signal detection method for mobile radio communications. The HTS scheme utilizes different modulation or coding methods for different MIMO streams, and the blind detection method requires no training sequences for signal separation, detection, and channel estimation. The HTS scheme can remove the ambiguity in identifying separated streams without unique words that are necessary in conventional MIMO blind detection. More specifically, two examples of HTS are considered: modulation type HTS (MHTS) and timing-offset type HTS (THTS). MHTS, which utilizes different modulation constellations with the same bandwidth for different streams, has been previously investigated. This paper proposes THTS which utilizes different transmission timing with the same modulation. THTS can make the blind detection more robust and effective with fractional sampling. The blind joint processing of detection and channel estimation performs adaptive blind MIMO-MLSE and is derived from an adaptive blind MLSE equalizer that employs the recursive channel estimation with the Moore-Penrose generalized inverse. Computer simulations show that the proposed system can achieve superior BER performance with Eb/N0 degradation of 1dB in THTS and 2.5dB in MHTS compared with the ideal maximum likelihood detection.

Kanno, Issei; Suzuki, Hiroshi; Fukawa, Kazuhiko

371

An implanted spherical head model exposed to electromagnetic fields at a mobile communication frequency.  

PubMed

Can cellular phones and personal communication systems base station antennas affect the active or passive implantable medical devices adversely? Concerns over the possible harmful effects of nonionizing irradiaton upon implanted medical devices have been present for many years. Key issues to address are the questions of whether mobile phones have a detrimental effect on implants, and how the interaction of the handset with the body can be minimized in order to both alleviate public fears and improve handset antenna performance and new implant designs. This paper presents a thorough investigation of the scattering of an electromagnetic (EM) wave from a perfectly conducting implant (a cylindrical wire and a very thin cylindrical disk) of electrically small radius (of resonant length), embedded eccentrically into a dielectric spherical head model by a dipole antenna (0.4 wavelength) at 900 MHz. The dyadic Green's function (DGF) for spherical vector wave functions is employed. Analytical expressions for the scattered fields of an implant embedded head model is obtained. Numerical results from analytical expressions are computed for this problem and then compared with the results from the same model using the finite-difference time-domain, EMU-FDTD electromagnetic simulator. Good agreement is observed between the analytical results on the proposed method in comparison with the FDTD method. PMID:17019874

Reyhani, S M S; Ludwig, Simone A

2006-10-01

372

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Communication Devices Featuring Digital Cameras, and Components Thereof; Notice of Investigation...communication devices featuring digital cameras, and components thereof by reason of...communication devices featuring digital cameras, or [[Page 8113

2010-02-23

373

The application of a novel two-way mobile satellite communications and vehicle tracking system to the transportation industry  

Microsoft Academic Search

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

I. M. Jacobs; A. Salmasi; T. J. Bernard

1991-01-01

374

A comparison study of the uplink performance of W-CDMA and OFDM for mobile multimedia communications via LEO satellites  

Microsoft Academic Search

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

A. Papathanassiou; A. K. Salkintzis; P. T. Mathiopoulos

2001-01-01

375

Call-based Fraud Detection in Mobile Communication Networks using a Hierarchical  

E-print Network

by a mobile phone theft, by cloning the mobile phone card or by acquiring a subscription with false calls originating from one subscription, evidencing card cloning. While this procedure efficiently which detects card cloning by using an upper speed limit at which a mobile phone user can travel

Tresp, Volker

376

Effects of GSM cellular phones on human hearing: the European project "GUARD".  

PubMed

The European multicenter project named GUARD involved nine centers and aimed to assess potential changes in auditory function as a consequence of exposure to low-intensity electromagnetic fields (EMFs) produced by GSM cellular phones. Participants were healthy young adults without any evidence of hearing or ear disorders. Auditory function was assessed immediately before and after exposure to EMFs, and only the exposed ear was tested. The procedure was conducted twice in a double blinded design, once with a genuine EMF exposure and once with a sham exposure (at least 24 h apart). Tests for assessment of auditory function were hearing threshold level (HTL), transient otoacoustic emissions (TEOAE), distortion product otoacoustic emissions (DPOAE), and auditory brainstem response (ABR). The exposure consisted of speech at a typical conversational level delivered via an earphone to one ear, plus genuine or sham EMF exposure. The EMF exposure used the output of a software-controlled consumer cellular phone at full power for 10 min. A system of phone positioning that allowed participants to freely move their heads without affecting exposure was used. Analysis of the data showed there were no effects of exposure to GSM mobile phone signals on the main measures of the status of the auditory system. PMID:17973552

Parazzini, Marta; Brazzale, Alessandra R; Paglialonga, Alessia; Tognola, Gabriella; Collet, Lionel; Moulin, Annie; Lutman, Mark E; Bell, Steven L; Thomas, Nathan A; Uloziene, Ingrida; Uloza, Virgijlius; Thuroczy, Gyorgy; Tavartkiladze, George; Tsalighopoulos, Miltos; Kyriafinis, Giorgio; Ravazzani, Paolo

2007-11-01

377

Location leaks on the GSM air interface Denis Foo Kune, John Koelndorfer, Nicholas Hopper, Yongdae Kim  

E-print Network

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

Minnesota, University of

378

SPEECH RECOGNITION FROM GSM CODEC PARAMETERS Juan M. Huerta and Richard M. Stern  

E-print Network

SPEECH RECOGNITION FROM GSM CODEC PARAMETERS Juan M. Huerta and Richard M. Stern Department that has been coded using the 13-kbps full-rate GSM codec, a Regular Pulse Excited Long Term Prediction (RPE-LTP) codec. The GSM codec devel- ops separate representations for the linear prediction (LPC

Stern, Richard

379

ROBUST SPEAKER VERIFICATION FROM GSM-TRANSCODED SPEECH BASED ON DECISION FUSION AND FEATURE TRANSFORMATION  

E-print Network

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

Mak, Man-Wai

380

CapacityAssignment Optimisation for Wireless GSM Cells D.D. Kouvatsos and S. Tantos  

E-print Network

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

Ould-Khaoua, Mohamed

381

Towards the Software Realization of a GSM Base Thierry Turletti, Hans Bentzen and David Tennenhouse  

E-print Network

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

Turletti, Thierry

382

Experimental Evaluation of the Impact of Network Frequency Synchronization on GSM Quality of Service During Handover  

E-print Network

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

Bregni, Stefano

383

DETECTION AND BLANKING OF GSM INTERFERENCE IN RADIO-ASTRONOMICAL OBSERVATIONS  

E-print Network

DETECTION AND BLANKING OF GSM INTERFERENCE IN RADIO-ASTRONOMICAL OBSERVATIONS Amir Leshem, Alle, satellite and broad- cast services. In particular, the GSM band is a highly satu- rated domain, full to radio astronomy, and the GSM sys- tem which became ubiquitous and thus prevents observation in its band

van der Veen, Alle-Jan

384

Programme Specification MA GSM&J Programme Specification 2013/14, Page 1 of 9  

E-print Network

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

Subramanian, Sriram

385

Location Leaks on the GSM Air Interface Denis Foo Kune, John Koelndorfer, Nicholas Hopper, Yongdae Kim  

E-print Network

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

Dahlberg, E. Dan

386

Modeling Framelevel Errors in GSM Wireless Channels Ping Ji, Benyuan Liu, Don Towsley and Jim Kurose  

E-print Network

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

Massachusetts at Amherst, University of

387

An Empirical Study on Statistical Properties of GSM Telephone Call Arrivals  

E-print Network

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

Bregni, Stefano

388

Initial experience with a handheld device digital imaging and communications in medicine viewer: OsiriX mobile on the iPhone.  

PubMed

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

Choudhri, Asim F; Radvany, Martin G

2011-04-01

389

Communication.  

ERIC Educational Resources Information Center

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,…

Strauss, Andre

390

Power and spectrally efficient M-ARY QAM schemes for future mobile satellite communications  

NASA Technical Reports Server (NTRS)

An effective method to compensate nonlinear phase distortion caused by the mobile amplifier is proposed. As a first step towards the future use of spectrally efficient modulation schemes for mobile satellite applications, we have investigated effects of nonlinearities and the phase compensation method on 16-QAM. The new method provides about 2 dB savings in power for 16-QAM operation with cost effective amplifiers near saturation and thereby promising use of spectrally efficient linear modulation schemes for future mobile satellite applications.

Sreenath, K.; Feher, K.

1990-01-01

391

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

Federal Register 2010, 2011, 2012, 2013, 2014

...Telephones and Wireless Communication Devices Featuring Digital Cameras, and Components Thereof; Notice of Commission Determination...telephones and wireless communication devices featuring digital cameras, and components thereof, that infringe certain claims...

2010-07-28

392

IEEE Wireless Communications February 2014 331536-1284/14/$25.00 2014 IEEE MOBILE SOCIAL NETWORKS  

E-print Network

remain between smartphone users (SUs) and Internet service providers (ISPs). Web-based/ password-range wireless communications such as near field communication (NFC), Bluetooth, and WiFi Direct. For example

Shen, Xuemin "Sherman"

393

Manufacturing consent?: Media messages in the mobilization against HIV/AIDS in India and lessons for health communication.  

PubMed

Despite repeated calls for a more critical and "culture-centered" approach to health communication, textual analysis of televised public service advertising (PSA) campaigns has been largely neglected, even by critical communication scholars. In the case of "developing" countries in particular, there is an acute shortage of such literature. On the other hand, following the outbreak of major public health diseases such as AIDS, most countries have adopted PSA campaigns as the most preferred means of communicating messages. Drawing on insights from cultural studies (especially Antonio Gramsci and Stuart Hall), this article engages in textual analysis of the televised PSA campaigns launched by the Indian state to prevent HIV/AIDS between 2002 and 2005. Through such analysis, it argues that although few diseases in Indian history have spurred such massive and creative efforts for mass mobilization as AIDS, these efforts, in terms of their ethical implications, have been far from emancipatory. In fact, they have constructed and perpetuated the logic of domination and control along class, gender, sexuality, and knowledge systems, often contradicting and potentially harming the very goal of HIV prevention and of health promotion and empowerment. This article also holds that assessing public health campaigns through textual analysis, a highly neglected tool in health communication, can shed important light on a far more complex and changing nature of the state and public policy, especially in the developing world, thereby opening up space for alternative theorizing for health communication and social change. PMID:23631645

Khan, Shamshad

2014-01-01

394

1800 MHz in vitro exposure device for experimental studies on the effects of mobile communication systems.  

PubMed

A wire patch cell (WPC) operating at the uplink frequency band of GSM 1800 MHz has been designed for in vitro experiments with the aim of investigating the possible biological effects of electromagnetic radiation associated with cellular phones. The 1800 MHz WPC design is a direct descendant of the original 900 MHz WPC introduced by Laval et al. This system provides a homogeneous specific absorption rate distribution, using four 3.5 cm petri dishes simultaneously. Numerical dosimetry has been performed using a commercial code (CST Microwave Studio), in order to evaluate accurately the efficiency of the structure (in terms of W kg(-1) per 1 W input power) and the distribution in the chosen biological target. The numerical results have been confirmed by experimental measurements performed by measuring thermal increase due to a high power impulse. The efficiency of the structure is 1.25 +/- 25% W kg(-1) per 1 W input power higher than the efficiency of the 900 MHz WPC. A few adjustments have been made in order to use the WPC in a standard incubator and to avoid thermal increases related to the radio frequency exposure. This exposure system has been adopted for the experiments scheduled in the RAMP and GUARD projects (VFPE). PMID:15494360

Ardoino, L; Lopresto, V; Mancini, S; Pinto, R; Lovisolo, G A

2004-01-01

395

A 90-nm CMOS Low-Power GSM\\/EDGE Multimedia-Enhanced Baseband Processor With 380MHz ARM926 Core and Mixed-Signal Extensions  

Microsoft Academic Search

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

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

396

Human exposure assessment in the near field of GSM base-station antennas using a hybrid finite element\\/method of moments technique  

Microsoft Academic Search

A hybrid finite-element method (FEM)\\/method of moments (MoM) technique is employed for specific absorption rate (SAR) calculations in a human phantom in the near field of a typical group special mobile (GSM) base-station antenna. The MoM is used to model the metallic surfaces and wires of the base-station antenna, and the FEM is used to model the heterogeneous human phantom.

Frans J. C. Meyer; David B. Davidson; Ulrich Jakobus; Maria A. Stuchly

2003-01-01

397

Ericsson\\/Mannesmann GSM field-trials with adaptive antennas  

Microsoft Academic Search

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

S. Anderson; U. Forssen; J. Karlsson; T. Witzschel; P. Fischer; A. Krug

1997-01-01

398

Multiple reuse patterns for frequency planning in GSM networks  

Microsoft Academic Search

Providing high capacity in GSM networks at low costs using existing macrocells is of increasing importance in the near future due to the competition between operators. This paper shows that by applying frequency hopping in combination with an advanced frequency planning method, multiple reuse patterns, very high traffic levels in the existing macrocells can be supported. Field experience from live

Stefan Engstrom; Thomas Johansson; Fredric Kronestedt; Magnus Larsson; Stefan Lidbrink; H. Olofsson

1998-01-01

399

A direct conversion transceiver for multi-band GSM application  

Microsoft Academic Search

The use of direct conversion receiver topologies has been marked by many technical problems, particularly when used in a TDMA environment. This paper describes a receiver architecture that overcomes many of the traditional problems associated with direct conversion. This architecture has been applied in the design of a GSM multi-band transceiver that also features a development of the offset PLL

Jon Strange; Simon Atkinson

2000-01-01

400

Improving roamer retention by exposing weak locations in GSM networks  

Microsoft Academic Search

One of the most valuable clients of cellular GSM networks are roaming clients, due to the pricing policy set by network operators. Despite that each operator applies a lot of effort in network signal coverage in order to achieve the best conditions for roaming traffic in the network, there still remain hardly detectable locations where roaming clients are getting lost

Michal Ficek; Lukás Kencl

2009-01-01

401

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, ACCEPTED FOR PUBLICATION 1 Vehicular Passenger Mobility-Aware  

E-print Network

for vehicular networks, mobile hotspot, which introduces an integrated architecture of wireless local area networks (WLAN) and wireless wide area networks (WWAN). Mobile hotspots can provide ex- tended service of both call admission control and bandwidth adjustment functions to lower handoff vehicle service

Shen, Xuemin "Sherman"

402

Improving Mobile Solution Workflows and Usability Using Near Field Communication Technology  

Microsoft Academic Search

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

Päivi Jaring; Vili Törmänen; Erkki Siira; Tapio Matinmikko

2007-01-01

403

The DRL Underwater Sensor Network: Supporting Dual Communications, Sensing, and Mobility  

E-print Network

network supports mobile nodes such as our underwater robot called the Au- tonomous Modular Optical in the ocean. The hardware consists of static sensor network nodes and mobile robots that are dually networked Underwater Robot (AMOUR), shown in Figure 2. It is 11kg. with a maximum speed of 1m/s. It has a battery life

Farritor, Shane

404

Satellite-aided mobile radio concepts study: Concept definition of a satellite-aided mobile and personal radio communication system  

NASA Technical Reports Server (NTRS)

The satellite system requires the use of a large satellite antenna and spacecraft array power of about 12 kW or more depending on the operating frequency. Technology developments needed include large offset reflector multibeam antennas, satellite electrical power sybsystems providing greater than 12 kW of power, signal switching hardware, and linearized efficient solid state amplifiers for the satellite-aided mobile band. Presently there is no frequency assignment for this service, and it is recommended that an allocation be pursued. The satellite system appears to be within reasonable extrapolation of the state of the art. It is further recommended that the satellite-aided system spacecraft definition studies and supporting technology development be initiated.

Anderson, R. E.

1979-01-01

405

MAP Receiver with Spatial Filters for Suppressing Cochannel Interference in MIMO-OFDM Mobile Communications  

NASA Astrophysics Data System (ADS)

This paper proposes joint maximum a posteriori (MAP) detection and spatial filtering for MIMO-OFDM mobile communications; it offers excellent receiver performance even over interference-limited channels. The proposed joint processor consists of a log likelihood generator and a MAP equalizer. The log likelihood generator suppresses cochannel interference by spatially filtering received signals and provides branch metrics of transmitted signal candidates. Using the branch metrics, the MAP equalizer generates log likelihood ratios of coded bits and performs channel decoding based on the MAP criterion. In the first stage, the log likelihood generator performs spatio-temporal filtering (STF) of the received signals prior to the fast Fourier transform (FFT) and is referred to as preFFT-type STF. Estimation of parameters including tap coefficients of the spatio-temporal filters and equivalent channel impulse responses of desired signals is based on the eigenvalue decomposition of an autocorrelation matrix of both the received and transmitted signals. For further improvement, in the second stage, the generator performs spatial filtering (SF) of the FFT output and is referred to as postFFT-type SF. Estimation of both tap coefficients of the spatial filters and channel impulse responses employs the recursive least squares (RLS) with smoothing. The reason for switching from preFFT-type STF into postFFT-type SF is that preFFT-type STF outperforms postFFT-type SF with a limited number of preamble symbols while postFFT-type SF outperforms preFFT-type STF when data symbols can be reliably detected and used for the parameter estimation. Note that there are two major differences between the proposed and conventional schemes: one is that the proposed scheme performs the two-stage processing of preFFT-type STF and postFFT-type SF, while the other is that the smoothing algorithm is applied to the parameter estimation of the proposed scheme. Computer simulations demonstrate that the proposed scheme can achieve excellent PER performance under interference-limited channel conditions and that it can outperform the conventional joint processing of preFFT-type STF and the MAP equalizer.

Lisheng, Fan; Fukawa, Kazuhiko; Suzuki, Hiroshi; Suyama, Satoshi

406

Patient-Provider Communications in Outpatient Clinic Settings: A Clinic-Based Evaluation of Mobile Device and Multimedia Mediated Communications for Patient Education  

PubMed Central

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

Schooley, Benjamin; San Nicolas-Rocca, Tonia

2015-01-01

407

Color-filter-free spatial visible light communication using RGB-LED and mobile-phone camera.  

PubMed

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

Chen, Shih-Hao; Chow, Chi-Wai

2014-12-15

408

76 FR 17347 - Aviation Communications  

Federal Register 2010, 2011, 2012, 2013, 2014

...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...

2011-03-29

409

Database correlation method for GSM location  

Microsoft Academic Search

Cellular location methods based on angle of arrival (AOA) or time difference (e.g. E-OTD) measurements assume line-of-sight propagation between base stations and the mobile station. This assumption is not valid in urban microcellular environments. We present a database correlation method (DCM) that can utilize any location-dependent signals available in cellular systems. This method works best in densely built urban areas.

Heikki Laitinen; Jaakko Lahteenmaki; Tero Nordstrom

2001-01-01

410

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

Federal Register 2010, 2011, 2012, 2013, 2014

...of major storms, including Superstorm Sandy in 2012, have impaired mobile wireless service in affected regions. Hurricane...be considered ``operational''? Are there ambiguous or borderline cases in which a site may or may not be...

2013-11-18

411

Enabling Secure and Spontaneous Communication between Mobile Devices using Common Radio Environment  

Microsoft Academic Search

With the proliferation of mobile devices, spontaneous interactions between co-located devices that do not know each other a priori will become commonplace. Securing these interactions against eavesdropping and man-in-the-middle attacks is an important and challenging task. In this paper, we postulate that mobile devices that are positioned in close proximity may be able to derive a shared secret to secure

Alex Varshavsky; Anthony LaMarca; Eyal de Lara

2007-01-01

412

Wireless Networks 5 (1999) 467477 467 Active tracking: Locating mobile users in personal communication  

E-print Network

is evaluated under two registration strategies: The geographic-based strategy, currently used in cellular communication service networks Hanoch Levy and Zohar Naor Department of Computer Science, School of Mathematics Communication Service (PCS) networks is discussed. We propose a novel approach for reducing the wireless cost

Levy, Hanoch

413

Efficient tag-to-tag near field communication (NFC) protocol for secure mobile payment  

Microsoft Academic Search

Communication between the near field communication (NFC) devices occurs in a very close distance of less than 10 cm. In the NFC-based payment system, close proximity between devices will increase the security of transactions. The disadvantage is the interaction between devices requires more physical activity of device owners because the device must be brought near to other devices some times.

Emir Husni; Kuspriyanto; Noor Basjaruddin; Tito Purboyo; Sugeng Purwantoro; Huda Ubaya

2011-01-01

414

Designing public safety mobile applications for disconnected, interrupted, and low bandwidth communication environments  

Microsoft Academic Search

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)}

P. Erickson; A. Weinert; P. Breimyer; M. Samperi; J. Huff; C. Parra; S. Miller

2013-01-01

415

Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications  

NASA Technical Reports Server (NTRS)

Current onboard communication architectures are based upon an all-in-one communications management unit. This unit and associated radio systems has regularly been designed as a one-off, proprietary system. As such, it lacks flexibility and cannot adapt easily to new technology, new communication protocols, and new communication links. This paper describes the current avionics communication architecture and provides a historical perspective of the evolution of this system. A new onboard architecture is proposed that allows full use of commercial-off-the-shelf technologies to be integrated in a modular approach thereby enabling a flexible, cost-effective and fully deployable design that can take advantage of ongoing advances in the computer, cryptography, and telecommunications industries.

Ivancic, William D.

2007-01-01

416

Modular, Cost-Effective, Extensible Avionics Architecture for Secure, Mobile Communications  

NASA Technical Reports Server (NTRS)

Current onboard communication architectures are based upon an all-in-one communications management unit. This unit and associated radio systems has regularly been designed as a one-off, proprietary system. As such, it lacks flexibility and cannot adapt easily to new technology, new communication protocols, and new communication links. This paper describes the current avionics communication architecture and provides a historical perspective of the evolution of this system. A new onboard architecture is proposed that allows full use of commercial-off-the-shelf technologies to be integrated in a modular approach thereby enabling a flexible, cost-effective and fully deployable design that can take advantage of ongoing advances in the computer, cryptography, and telecommunications industries.

Ivancic, William D.

2006-01-01

417

An Investigation into the Use of 3G Mobile Communications to Provide Telehealth Services in Rural KwaZulu-Natal.  

PubMed

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

Clarke, Malcolm; Mars, Maurice

2014-06-13

418

Supplanting copper : pricing and quality of GSM telecom services in Africa  

E-print Network

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 ...

Oyeyinka, Oyebanke (Oyebanke Nihinlolawa)

2008-01-01

419

Application of mobile digital communications in law enforcement, an introductory planning guide  

NASA Technical Reports Server (NTRS)

A set of planning guidelines for the application of digital communications techniques to law enforcement use is presented. Some essential characteristics of digital techniques and their applications are outlined, as are some principles of system analysis, evaluation, and planning. Requirements analysis, system concept design, implementation planning, and performance and cost modeling are described and demonstrated with respect to this application problem. Information on law enforcement digital communications systems and equipment and a list of vendor sources are given in appendices.

Sohn, R. L.; Abraham, J. E.; Leflang, W. G.; Kennedy, R. D.; Wilson, J. H.; Gurfield, R. M.

1975-01-01

420

EDGE: enhanced data rates for GSM and TDMA\\/136 evolution  

Microsoft Academic Search

Two of the major second-generation standards, GSM and TDMA\\/136, have built the foundation to offer a common global radio access for data services. Through use of a common physical layer, EDGE, both standards will have the same evolutionary path toward providing third-generation services. EDGE is currently subject to standardization in TIA TR45.3 and ETSI SMG, a process which will be

ANDERS FURUSKAR; SARA MAZUR; FRANK MULLER; HAKAN OLOFSSON

1999-01-01

421

Silicon-on-silicon integration of a GSM transceiver with VCO resonator  

Microsoft Academic Search

Accurate and spurious-free design of an integrated VCO resonator in a GSM transceiver is demonstrated. The high-Q inductor (Q=60 at 1 GHz) in the resonator is on a high-resistivity silicon substrate and the GSM chip is flip-chip mounted on the same substrate. The VCO meets all GSM requirements: phase noise is-142 dBc\\/Hz at 10 MHz from the 1018 MHz center

P. Davis; P. Smith; E. Campbell; J. Lin; K. Gross; G. Bath; Y. Low; M. Lau; Y. Degani; J. Gregus; R. Frye; K. Tai

1998-01-01

422

Dveloppement et intgration d'une antenne relais GSM/3G dans un chargeur inductif  

E-print Network

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 systèmes relais GSM/3G: relais analogique par couplage en champ

Dobigeon, Nicolas

423

Analysis of beam-steering and directive characteristics of adaptive antenna arrays for mobile communications  

Microsoft Academic Search

Radiation patterns of planar, circular, and three-segment adaptive antenna arrays are analyzed and compared in view of applications in mobile radio. It is assumed that each array consisted of several subarrays, which themselves present vertical linear arrays (columns) of patch radiators, with prescribed magnitude and phase distributions that determine the beam shape in the vertical (elevation) direction. Weighting signals applied

V. Kallnichev

2001-01-01

424

Capacity of a Mobile Multiple-Antenna Communication Link in Rayleigh Flat Fading  

Microsoft Academic Search

We analyze a mobile wireless link comprising transmitter and receiver antennas operating in a Rayleigh flat-fading environment. The propagation coef ficients between every pair of transmitter and receiver antennas are statistically independent and un known; they remain constant for a coherence interval of symbol periods, after which they change to new independent values which they maintain for another symbol periods,

Thomas L. Marzetta; Bertrand M. Hochwald

1999-01-01

425

n an ad hoc network, mobile nodes communicate with each other using multihop wireless  

E-print Network

) to develop a routing frame- work for IP-based protocols in ad hoc networks. Our goal is to carry out a systematic performance study of two dynamic routing protocols for ad hoc networks: the Dynamic Source Routing routing protocols for mobile ad hoc networks. The rest of the article is organized as follows. In the fol

Belding-Royer, Elizabeth M.

426

Divergent Perspectives on Language-Discordant Mobile Medical Professionals' Communication with Colleagues: An Exploratory Study  

ERIC Educational Resources Information Center

Little is known about how language-discordant mobile medical professionals (MMPs), defined as doctors who work in foreign countries, cultures, and languages, interact with their colleagues. The number of MMPs around the world is growing, and their interactions with colleagues have direct consequences for both patients' health and their own…

Gasiorek, Jessica; van de Poel, Kris

2012-01-01

427

Socializing Messages in Blue-Collar Families: Communicative Pathways to Social Mobility and Reproduction  

ERIC Educational Resources Information Center

This study explicitly links processes of anticipatory socialization to social mobility and reproduction. An examination of the socializing messages exchanged between blue-collar parents (n = 41) and their children (n = 25) demonstrate that family-based messages about work and career seldom occur in straightforward, unambiguous ways. Instead,…

Lucas, Kristen

2011-01-01

428

Towards music download and radio broadcast convergence in mobile communications networks  

Microsoft Academic Search

The transition from physical to digital music distribution is bound to have profound implications on the music industry. So far, most of the activity related to digital music distribution has been centred on the fixed Internet. In the meantime, mobile operators have been making significant investments in extending their network capabilities to support data services. This paper includes an analysis

Sandro Grech; Sakari Luukkainen

2005-01-01

429

Performance Modeling and Analysis of a Handover Channel Exchange Scheme in Mobile Cellular Communication Systems  

Microsoft Academic Search

Properly designed handover procedures in cellular wireless systems are essential for maintaining continuity of a call in progress and for minimizing the probability of forced call termination and signaling and switching load on the network. In this paper, we model a channel exchange scheme that involves exchange of channels between two mobiles that are moving in opposite directions across the

Manpreet Singh Dang; Amol Prakash; Rajeev Shorey; Natwar Modani; Dinesh K. Anvekar

2000-01-01

430

Ultra-low Power Sensors with Near Field Communication for Mobile Applications  

Microsoft Academic Search

In this paper, we study the applicability of an emerging RFID-based communication technology, NFC (Near Field Communication),\\u000a to ultra-low power wireless sensors. We present potential application examples of passive and semi-passive NFC-enabled sensors.\\u000a We compare their NFC-based implementations to corresponding implementations based on short-range radios such as Bluetooth\\u000a and Wibree. The comparison addresses both technical properties and usability. We also

Esko Strömmer; Mika Hillukkala; Arto Ylisaukko-oja

431

The generation of simple compliance boundaries for mobile communication base station antennas using formulae for SAR estimation.  

PubMed

In this paper, a procedure is proposed for generating simple and practical compliance boundaries for mobile communication base station antennas. The procedure is based on a set of formulae for estimating the specific absorption rate (SAR) in certain directions around a class of common base station antennas. The formulae, given for both whole-body and localized SAR, require as input the frequency, the transmitted power and knowledge of antenna-related parameters such as dimensions, directivity and half-power beamwidths. With knowledge of the SAR in three key directions it is demonstrated how simple and practical compliance boundaries can be generated outside of which the exposure levels do not exceed certain limit values. The conservativeness of the proposed procedure is discussed based on results from numerical radio frequency (RF) exposure simulations with human body phantoms from the recently developed Virtual Family. PMID:19531847

Thors, B; Hansson, B; Törnevik, C

2009-07-01

432

Study on the spectral efficiency of SFH-GMSK in land mobile telephone communication by direct simulation  

NASA Technical Reports Server (NTRS)

A spread spectrum system, slow frequency hopping with GMSK (Gaussian minimum shift keying) modulation (SFH-GMSK), is proposed for mobile telephone communications. The system performance is evaluated using computer simulation and is compared with an unspread system. Results show that under multipath fading conditions, when the signal-to-noise ratio (SNR) is greater than 15 dB, slow frequency hopping gives some bit error rate improvement over the unspread system. Theoretical predictions indicate that a system efficiency of 20-65 users per cell can be achieved in the cellular configuration. Joint use of SFH-GMSK and FM is also investigated. It is shown that FM interference can cause serious degradation to the SFH-GMSK performance.

Bao, H.; Kwatra, S. C.; Kim, Junghwan; Stevens, G. H.

1990-01-01

433

A numerical coefficient for evaluation of the environmental impact of electromagnetic fields radiated by base stations for mobile communications.  

PubMed

The aim of this study is the development of an Electromagnetic Environmental Impact Factor (EEIF). This is a global parameter that represents the level of electromagnetic impact on a specific area due to the presence of radiating systems, such as base station (BS) antennas for mobile communications. The numerical value of the EEIF depends only on the electromagnetic field intensity, a well-defined physical quantity that can easily be measured or computed. The paper describes the significant parameters of the field distribution adopted to evaluate the EEIF, and the assumptions used to develop a proper scale of values. Finally, some examples of application of the EEIF method are analyzed for real situations in a typical urban area. PMID:20690166

Russo, P; Cerri, G; Vespasiani, V

2010-12-01

434

Dual-Band Horn Array Design Using a Helical Exciter for Mobile Satellite Communication Terminals  

Microsoft Academic Search

A horn array antenna is proposed for dual-band and dual-polarization operation. The array is optimally designed to be used as a feeder in mobile satellite terminals with a hybrid antenna (HA) structure, but it can be also used independently as a phased array. The array has an oval-shaped rim to maximize the efficiency of the HA, and is composed of

Young-Bae Jung; Soon-Young Eom

2012-01-01

435

A New Frequency Partitioning and Allocation of Subcarriers for Fractional Frequency Reuse in Mobile Communication Systems  

NASA Astrophysics Data System (ADS)

Some OFDMA-based wireless commuication systems, e. g., Wireless Broadband Internet (WiBro) or Worldwide interoperability for Microwave Access (WiMAX), support frequency reuse of 1 to maximize spectral efficiency. One of the efficient methods to reduce co-channel interference (CCI) caused by frequency reuse is fractional frequency reuse (FFR). In this paper, we propose and validate a novel frequency partitioning method and subcarrier assignment mechanism to improve system and individual capacity of mobile systems using FFR.

Han, Seung Su; Park, Jongho; Lee, Tae-Jin; Ahn, Hyun Gi; Jang, Kyunghun

436

A second anniversary operational review of the OmniTRACS(R): The first two-way mobile Ku-band satellite communications system  

NASA Technical Reports Server (NTRS)

A novel two-way mobile satellite communications and vehicle position reporting system that is currently operational in the United States and Europe is described. The system characteristics and service operations are described in detail. Technical descriptions of the equipment and signal processing techniques are provided.

Jacobs, Irwin M.; Salmasi, Allen; Gilhousen, Klein S.; Weaver, Lindsay A., Jr.; Bernard, Thomas J.

1990-01-01

437

A Low-Cost GPS GSM/GPRS Telemetry System: Performance in Stationary Field Tests and Preliminary Data on Wild Otters (Lutra lutra)  

PubMed Central

Background Despite the increasing worldwide use of global positioning system (GPS) telemetry in wildlife research, it has never been tested on any freshwater diving animal or in the peculiar conditions of the riparian habitat, despite this latter being one of the most important habitat types for many animal taxa. Moreover, in most cases, the GPS devices used have been commercial and expensive, limiting their use in low-budget projects. Methodology/Principal Findings We have developed a low-cost, easily constructed GPS GSM/GPRS (Global System for Mobile Communications/General Packet Radio Service) and examined its performance in stationary tests, by assessing the influence of different habitat types, including the riparian, as well as water submersion and certain climatic and environmental variables on GPS fix-success rate and accuracy. We then tested the GPS on wild diving animals, applying it, for the first time, to an otter species (Lutra lutra). The rate of locations acquired during the stationary tests reached 63.2%, with an average location error of 8.94 m (SD?=?8.55). GPS performance in riparian habitats was principally affected by water submersion and secondarily by GPS inclination and position within the riverbed. Temporal and spatial correlations of location estimates accounted for some variation in the data sets. GPS-tagged otters also provided accurate locations and an even higher GPS fix-success rate (68.2%). Conclusions/Significance Our results suggest that GPS telemetry is reliably applicable to riparian and even diving freshwater animals. They also highlight the need, in GPS wildlife studies, for performing site-specific pilot studies on GPS functioning as well as for taking into account eventual spatial and temporal correlation of location estimates. The limited price, small dimensions, and high performance of the device presented here make it a useful and cost-effective tool for studies on otters and other aquatic or terrestrial medium-to-large-sized animals. PMID:22242163

Quaglietta, Lorenzo; Martins, Bruno Herlander; de Jongh, Addy; Mira, António; Boitani, Luigi

2012-01-01

438

Small-Scale Design Experiments as Working Space for Larger Mobile Communication Challenges  

ERIC Educational Resources Information Center

In this paper, a design experiment using Instagram as a cultural probe is submitted as a method for analyzing the challenges that arise when considering the implementation of social media within a distributed communication space. It outlines how small, iterative investigations can reveal deeper research questions relevant to the education of…

Lowe, Sarah; Stuedahl, Dagny

2014-01-01

439

Recent trends in IP\\/NGEO satellite communication systems: transport, routing, and mobility management concerns  

Microsoft Academic Search

Non-geostationary (NGEO) satellite communication systems are seen as an attractive solution to realize the vision of anywhere, anytime pervasive access to the Internet. Their design and development have thus gained tremendous interest in the last few years. Commencing with a brief overview of general NGEO satellite configurations, this article next addresses the key technical difficulties in the development of NGEO

TARIK TALEB; Nei Kato; YOSHIAKI NEMOTO

2005-01-01

440

The design and performance of a modem for land mobile satellite communications  

NASA Technical Reports Server (NTRS)

The digital implementation and performance of a multipath fade-tolerant differentially coherent 8-PSK-based modem for a land mobile satellite experiment (MSAT-X) program is described. At the receiver, differential detection using a matched filter arrangement and feedforward Doppler compensation is employed to achieve several operational benefits. For this L-band satellite link, the channel utilization is an efficient 1.0 bps/Hz for raw data and 1.5 bps/Hz for coded data. The experimental data analysis shows that the modem functions over the fading channel and performs within 1 dB of theoretical or simulation estimates.

Jedrey, T. C.; Lay, N. E.; Rafferty, W.

1988-01-01

441

The complexity of social mobilization in health communication: top-down and bottom-up experiences in polio eradication.  

PubMed

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 informational perspectives to a focus on emerging challenges in polio eradication efforts and new levels of complexity to SM. We examine available literature on communication and public health, available data on SM experiences that support polio eradication in Africa and Asia, and field work conducted by the authors where polio eradication efforts are ongoing. Our analysis suggests that (1) SM should not be casually approached as a top-down informational strategy to advance pre-established health goals; (2) centralized strategies hardly amount to SM; and (3) hybrid options that combine both activist and pragmatic SM are concrete possibilities for global health initiatives. In the context of renewed global democratization and persistent conflicts rooted in ethnicity, religion, and economics, it cannot be assumed that communities will either diligently espouse global goals or necessarily oppose them. Communication and SM strategies should rely on a clear understanding of the motives and agendas of involved actors. Resistance or opposition are important analytical dimensions as they may uncover new opportunities for effective health interventions. Further studies using these perspectives should be a priority for global health programs, including studies of the trust level, or lack thereof, among social actors. PMID:20455165

Obregón, Rafael; Waisbord, Silvio

2010-01-01

442

Performance analysis of LDPC coded OFDM for mobile communications via LEO satellites  

NASA Astrophysics Data System (ADS)

This paper presents the performance analysis and optimization of LDPC coded OFDM system which provides high signal quality in LEO satellite communications. A three-state statistical channel model of LEO satellite channel is adopted including Rayleigh, Rician and shadowed Rician distributed submodels. The Irregular LDPC codes without loops of length 4 are optimized by the differential evolution algorithm under this LEO satellite channel. Simulations of BPSK, QPSK, 16QAM modulated systems are also conducted to analyze performances of theses systems.

Du, Bing; Zhang, Jun; Liu, Feng

2005-11-01

443

Media Affordances of a Mobile Push-To-Talk Communication Service  

Microsoft Academic Search

This paper presents an exploratory study of college-age students using two- way, push-to-talk cellular radios. We describe the observed and reported use of cellular radio by the participants, the activities and purposes for which they adopted it, and their responses. We then examine these empirical results using mediated communication theory. Cellular radios have a unique combination of affordances relative to

Allison Woodruff; Paul M. Aoki

2003-01-01

444

A High Speed, Long-Range Mobile Communications Link for use in Polar Regions  

NASA Astrophysics Data System (ADS)

The Polar Radar for Ice Sheet Measurements (PRISM) project has developed a high bandwidth, wireless communications link between an autonomous rover and a manned vehicle deployed on a polar ice sheet to exchange real-time video, timing signals for a bistatic radar, and rover sensory data. The PRISM project is developing advanced intelligent remote sensing technology that involves radar systems, an autonomous rover, and communications systems to measure detailed ice sheet characteristics, and to determine bed conditions (frozen or wet) below active ice sheets in both Greenland and Antarctica. While this wireless communications link is being developed to fill a need within the PRISM Project, the same technology will allow polar researchers separated by moderate distances ( ˜10 km) to exchange data. The communications link is based on a high data rate 802.11b wireless technology, and a prototype system has been tested and evaluated during field experiments conducted at the NorthGRIP ice core drilling camp in Greenland (75° 06\\'\\ N, 42° 20\\'\\ W) from June 23-July 17, 2003. The IEEE 802.11b standard works in the 2.4-2.483 GHz band and has been widely used for high-speed data transfer in a WLAN (Wireless Local Area Network). It typically has a range of a few hundred meters and theoretical data rates on the order of 11 Mbps. It has been used for a number of applications in home and office environments. We modified a 802.11b system to operate up to a maximum distance of about 8 km and investigated the radio propagation environment over the flat terrain of the Greenland ice sheet. We evaluated its performance along three different tracks of 8 km in length, and made throughput measurements at intervals of 0.5 km. We measured the received signal strength and noise level in 2-s intervals along these 8 km tracks. Also we conducted experiments for four different antenna heights (1, 2, 3 and 5 m) for developing a radio propagation model for WLAN communication over the ice sheet. We found that peer-to-peer communication between nodes on the ice had data rates varying from 4.5 Mbps at close range to 2.5 Mbps at a distance of 8 km from the base station. The design, propagation model, throughput and coverage of this peer-to-peer communications system in Greenland are presented in this paper. This WLAN system has numerous applications in polar field camps. We tested the transfer of real-time video segments across this link for our educational outreach efforts in the field. These video segments were subsequently uploaded using an Iridium-based Internet link, and sent back to the University of Kansas. The wireless Internet connectivity was also made available to members of the North Grip camp, who were able to access e-mail and the Internet from their tents and common areas. However, throughput for wireless access to the Internet was limited by the Iridium-based Internet connection that had a maximum bandwidth of 9.6 Kbps.

Chalishazar, N.; Prescott, G.; Braaten, D.

2003-12-01

445

Low gain and steerable vehicle antennas for communications with land mobile satellite  

NASA Technical Reports Server (NTRS)

Current development activities at JPL for ground mobile vehicle antennas to be used with the Land Mobile Satellite Service (LMSS) system are described. Both low gain and electronically steerable high gain type antennas are discussed in terms of their design concept and RF performance. For the low gain type, three classes of antennas are under various stages of development. These are the crossed-drooping dipole, quadrifilar helix, and microstrip patch designs. The antennas are intended to provide circularly-polarized radiation with a minimum of 3-dB gain in the angular region from 19 degrees to 60 deg from the horizon in elevation plane and with an omnidirectional pattern in azimuthal plane. For the electronically steerable high gain type, circularly-polarized microstrip patch phased arrays formed on a planar surface and on the surface of a truncated cone are under study. The arrays are intended to provide a minimum of 12 dB gain in the same angular region in elevation plane at all azimuthal angles. This coverage is accomplished by scanning the high gain pencil beam in both elevation and azimuthal directions. Both types of antennas are to transmit at 821-831 MHz band and to receive at 866-876 MHz band. They must be of low cost design and reasonably conformal to the vehicle.

Woo, K.

1982-01-01

446

Adaptive Decision Fusion for Multi-Sample Speaker Verification over GSM Ming-Cheung Cheung and Man-Wai Mak  

E-print Network

Adaptive Decision Fusion for Multi-Sample Speaker Verification over GSM Networks Ming-Cheung Cheung to the score model to obtain a likelihood for adapting the prior score. Experimental results based on the GSM to improve the performance of speaker veri- fication from GSM-transcoded speech. In addition to com- puting

Mak, Man-Wai

447

A Fully Integrated Dual-Mode Frequency Synthesizer for GSM and Wideband CDMA in 0.5m CMOS  

E-print Network

A Fully Integrated Dual-Mode Frequency Synthesizer for GSM and Wideband CDMA in 0.5µµµµm CMOS Yiwu University Columbus, OH 43210 Abstract A fully integrated dual-mode frequency synthesizer for GSM the two modes by applying fractional frequency synthesis to GSM mode and integer frequency synthesis

Bibyk, Steven B.

448

Modeling Frame-level Errors in GSM Wireless Channels Ping Ji, Benyuan Liu, Don Towsley and Jim Kurose  

E-print Network

1 Modeling Frame-level Errors in GSM Wireless Channels Ping Ji, Benyuan Liu, Don Towsley and Jim-level errors in GSM channels. One of these, the Markov-based Trace Analysis model (MTA), was developed for the purpose of model- ing a GSM channel. The next two, ¢ -th-order Markov models and hidden Markov models

Liu, Benyuan

449

A Knowledge Navigation Method for the Domain of Customers' Services of Mobile Communication Corporations in China  

NASA Astrophysics Data System (ADS)

Rapidly increasing amount of mobile phone users and types of services leads to a great accumulation of complaining information. How to use this information to enhance the quality of customers' services is a big issue at present. To handle this kind of problem, the paper presents an approach to construct a domain knowledge map for navigating the explicit and tacit knowledge in two ways: building the Topic Map-based explicit knowledge navigation model, which includes domain TM construction, a semantic topic expansion algorithm and VSM-based similarity calculation; building Social Network Analysis-based tacit knowledge navigation model, which includes a multi-relational expert navigation algorithm and the criterions to evaluate the performance of expert networks. In doing so, both the customer managers and operators in call centers can find the appropriate knowledge and experts quickly and exactly. The experimental results show that the above method is very powerful for knowledge navigation.

Wu, Jiangning; Wang, Xiaohuan

450

Performance and operational considerations in the design of vehicle antennas for mobile satellite communications  

NASA Technical Reports Server (NTRS)

This paper examines the vehicle antenna requirements for mobile satellite systems. The antenna parameters are discussed in the light of the requirements and the limitations in performance imposed by the physical constraints of antenna and by vehicle geometries. Measurements of diffraction and antenna noise temperature in an operational environment are examined, as well as their effects on system margins. Mechanical versus electronic designs are compared with regards to performance, cost, reliability, and design complexity. Comparisons between open-loop and close-loop tracking systems are made and the effects of bandwidth, sidelobe levels, operational constraints, vehicle angular velocity, and acceleration are discussed. Some consideration is given to the use of hybrid systems employing both open and closed-loop tracking. Changes to antenna/terminal specifications are recommended which will provide greater design flexibility and increase the likelihood of meeting the performance and operational requirements.

Milne, R.

1995-01-01

451

Global Interconnectivity Between Mobile Satellite and Terrestrial Users: Call Signalling Issues and Challenges  

NASA Technical Reports Server (NTRS)

This paper will discuss some of the challenges in connecting mobile satellite users and mobile terrestrial users in a cost efficient manner and with a grade of service comparable to that of satellite to fixed user calls. Issues arising from the translation between the mobility management protocols resident at the satellite Earth station and those resident at cellular switches - either GSM (Group Special Mobile) or IS-41 (used by U.S. digital cellular systems) type - will be discussed. The impact of GSM call routing procedures on the call setup of a satellite to roaming GSM user will be described. Challenges facing provision of seamless call handoff between satellite and cellular systems will be given. A summary of the issues explored in the paper are listed and future work outlined.

Estabrook, Polly; Moon, Todd; Spade, Rob

1996-01-01

452

Evaluating the efficacy of tuberculosis Advocacy, Communication and Social Mobilization (ACSM) activities in Pakistan: a cross-sectional study  

PubMed Central

Background Tuberculosis (TB) continues to be a major public health and development problem within many low- and middle-income countries. Although Advocacy, Communication and Social Mobilization (ACSM) activities have been undertaken in high TB burden countries to remediate these issues, there is little empirical evidence of the efficacy of these approaches. The purpose of this study was therefore to examine the efficacy of an ACSM program undertaken within Pakistan. Pakistan was chosen because it has received considerable funding for ACSM related activities and is one of 22 high-burden TB countries. Methods The program was evaluated by surveying a stratified random sample of 2,400 participants across 57 districts of Pakistan. Participants were categorized into one of three groups: aware of both media and community ACSM activities (AwareMedia&Community), aware of ACSM media activities only (AwareMedia), or unaware of any ACSM activities (UnawareMedia&Community). Results Independent measures ANCOVA revealed complex differences in knowledge, attitudes, and intended behaviors towards TB between the three groups. In general, UnawareMedia&Community cases had a poorer understanding of TB and its treatment, whilst awareness of ACSM activities was highest among literate and urban dwelling Pakistanis. Preferred sources of TB information were also found to vary by gender, geographic location, and literacy. Conclusions Whilst highlighting improvements in knowledge and attitudes toward TB, the results also provide invaluable insights into areas where further work needs to be done to address deficits in TB understanding, particularly among rural and illiterate Pakistanis. Equally important, the findings have implications for future TB ACSM initiatives in Pakistan in terms of leveraging the preferred media channels of key demographic segments and exploring the degree to which exposure to multiple channels of communication may have an additive effect on health knowledge. PMID:24295034

2013-01-01

453

Wireless optical transceiver design, link analisys and alignment control for mobile communication  

NASA Astrophysics Data System (ADS)

Pointing, acquisition and tracking of a free-space optical node in a mobile network experiencing misalignment due to adverse factors including vibration, motion and atmospheric turbulence requires a different approach than traditional free-space optical transceivers. A recent fiber-bundle approach for beam steering at the transmitter was investigated to provide continuous beam coverage at the receiver without the application of mechanical devices. Utilizing multiple fibers-lenses sets at the receiver was also proposed to enhance the tolerance of optical link misalignment. In this work, both laboratory experiments and software simulation were implemented to evaluate the optical link performance for different fiber-bundle-based transceiver setups as the link parameters were varied. The performance was evaluated in terms of the coverage area at the receiver, which is a measure of misalignment tolerance and is dependent not only on wavelength but on other key parameters such as link length, transmitted power, the pattern of transmitters, beam divergence, and the receiver construction. The results showed that fiber-bindle-based transceivers reveal significant potential to maximize the up time of the link, and the results also provide guidance on the further development of the overall system. To incorporate the proposed transceiver designs, an alignment control system was developed and evaluated as well. The laboratory results show that the optical control system successfully recovered and maintained the link while the receiver was in motion and the signal coverage at the target area was enhanced significantly.

Zhou, Dayong

454

3264 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 59, NO. 12, DECEMBER 2011 FDTD/GSM Analysis of Multilayered Periodic  

E-print Network

3264 IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 59, NO. 12, DECEMBER 2011 FDTD/GSM-selective surface (FSS), generalized scattering matrix (GSM), harmonics, periodic boundary condition (PBC). I is to compute the generalized scattering matrix (GSM) [3]­[6] for each layer and then obtain the total GSM

Elsherbeni, Atef Z.

455

A comparison of two methods to assess the usage of mobile hand-held communication devices.  

PubMed

ABSTRACT Objective: The purposes of this study were to: 1) examine agreement between self-reported measures of mobile device use and direct measures of use, and 2) understand how respondents thought about their device use when they provided self-reports. Methods: Self-reports of six categories of device use were obtained using a previously developed questionnaire, and direct measures of use were collected using a custom logging application (n = 47). Bland-Altman analyses were used to examine agreement between the two measurement approaches. Interviews targeted participants' experiences completing the device use section of the questionnaire. Results: Self-reports of use on a typical day last week overestimated logged use; overestimates tended to be low at low average usage times, and became more variable as usage time increased. Self-reports of use yesterday also exceeded logged use, however the degree of overestimation was less than for a typical day last week. Six themes were identified from interviews, including the thought process used by participants to arrive at usage and the ease of reporting usage. Discussion: It is challenging for respondents of this questionnaire to provide accurate self-reports of use. The source of this challenge may be attributed to the intrinsic difficulty of estimating use, partly due to the multiple functions of the devices as well as the variability of use both within a day and a week. Conclusion: Research investigating the relationship between device use and health outcomes should include a logging application to examine exposure simultaneously with self-reports to better understand the sources of hazardous exposures. PMID:25436479

Berolo, Sophia; Steenstra, Ivan; Amick, Benjamin C; Wells, Richard P

2014-12-01

456

Mobile Display of Information about Aggregated Antibiotic Resistance in the Hospital Setting Supported by Near Field Communication.  

PubMed

Antibiotic resistance is a heterogeneous phenomenon. It does not only differ between countries or states, but also between wards of hospitals, where different resistance patterns have been found. To support clinicians in administering empiric antibiotic therapy, we developed software to present information about antibiotic resistance using a mobile concept. A pre-existing infrastructure was deployed as the server component. The systems analyze and aggregate data from laboratory information systems, generating statistical data on antibiotic resistance. The information is presented to the Android client using a Representational State Transfer (REST) interface. Geographical localization is performed using near field communication (NFC) tags. The prototype provides tabulated data concerning antibiotic resistance patterns in the wards of a hospital. Using Android, NFC, and data caching, the usability of the system is estimated to be high. We hypothesize that antibiotic stewardship in hospitals can be supported by this software, thus improving medical monitoring of antibiotic resistance. Future studies in a productive environment are needed to measure the impact of the system on the outcome of patient care. PMID:24851968

Meng, Philipp; Fehre, Karsten; Rappelsberger, Andrea; Adlassnig, Klaus-Peter

2014-01-01

457

Joint Adaptive Modulation Coding and Cooperative ARQ over Relay Channels-Applications to Land Mobile Satellite Communications  

E-print Network

In a cooperative relay network, a relay node (R) facilitates data transmission to the destination node (D), when the latter is unable to decode the source node (S) data correctly. This paper considers such a system model and presents a cross-layer approach to jointly design adaptive modulation and coding (AMC) at the physical layer and cooperative truncated automatic repeat request (ARQ) protocol at the data link layer. We first derive a closed form expression for the spectral efficiency of the joint cooperative ARQ-AMC scheme. Aiming at maximizing this performance measure, we then optimize two AMC schemes for S-D and R-D links, which directly satisfy a prescribed packet loss rate constraint. As an interesting application, we also consider the problem of joint link adaptation and blockage mitigation in land mobile satellite communications (LMSC). We also present a new relay-assisted transmission protocol for LMSC, which delivers the source data to the destination via the relaying link, when the S-D channel is...

Mardani, Morteza; Lahouti, Farshad; Eliasi, Behrouz

2008-01-01

458

Parallel Simulation of Wireless Networks with TED: Radio Propagation, Mobility and Protocols  

Microsoft Academic Search

We describe the , a parallel simulation testbed for mobile wireless networks. In this article we emphasize the techniques for modeling of radio propagation (long- and short-scale fading and interference) and protocols for integrated radio resource management in mobile wireless voice networks. The testbed includes the standards-based AMPS, NA-TDMA and GSM protocols, and several research-oriented protocol families.

Jignesh Panchal; Owen Kelly; Jie Lai; Narayan B. Mandayam; Andarew T. Ogielski; Roy D. Yates

1998-01-01

459

Pointing, acquisition, and tracking considerations for mobile directional wireless communications systems  

NASA Astrophysics Data System (ADS)

High capacity directional wireless communications networks are an active research area because of their Gb/s or greater data rates over link lengths of many kilometers, providing fiber-like networks through the air. Their high data rates arise partly from their very high carrier frequencies (<60GHz for RF, and ~1550nm for free-space optical (FSO)) and partly because of their very narrow beamwidths. This second characteristic requires that transceivers be pointed precisely to their counterparts. In almost all cases this means that the transceiver aperture is mechanically pointed by a rotation stage, commonly known as a gimbal. How these platforms initially point at a target, acquire the signal, and then stay locked on the signal is known as pointing, acquisition, and tracking (PAT). Approaches for PAT in both RF and FSO have some similarities, but require overall divergent solutions, especially if the platforms are moving. This paper elaborates on the various considerations required for designing and implementing a successful PAT system for both directional RF and FSO systems. Approaches for GPS or beacon based pointing, types of acquisition scans, and the effects of platform vibration are analyzed. The acquisition time for a spiral scan of a given radius with an initial pointing error has been measured experimentally for a gimbal pointing system.

Rzasa, John; Ertem, Mehmet Can; Davis, Christopher C.

2013-09-01

460

Development and Comparison Between Resource Allocation Strategies Based on Intelligent Scheme and Traditional Distributed Dynamic Resource Allocation Strategies in Mobile Communication Networks  

Microsoft Academic Search

The third generation of mobile communication aims to transmit not only voice and text but also videos and multimedia data.\\u000a Furthermore, in the future it is expected to involve web browsing, file transfer, and database access. This requires wireless\\u000a cellular networks to efficiently support packet data traffic. Therefore, challenge in the design of wireless networks is to\\u000a support both voice

Jamal Raiyn

2007-01-01

461

Adaptive optimization of least-squares tracking algorithms: with applications to adaptive antenna arrays for randomly time-varying mobile communications systems  

Microsoft Academic Search

Adaptive antenna arrays are used for reducing the effects of interference and increasing capacity in mobile communications systems. Typical algorithms recursively compute the antenna weights that minimize the weighted error function (at discrete times kh, k=1,2,..., for a sampling interval h) ?l=1k?k-l[el(W)]2, where el(W) is a measure of the reception error at time lh with antenna weight vector W, and

Robert Buche; Harold J. Kushner

2005-01-01

462

EnLoc: Energy-Efficient Localization for Mobile Phones  

Microsoft Academic Search

A growing number of mobile phone applications uti- lize physical location to express the context of information. Most of these location-based applications assume GPS capabilities. Unfortunately, GPS incurs an unacceptable energy cost that can reduce the phone's battery life to less than nine hours. Alternate localization technologies, based on WiFi or GSM, improve battery life at the expense of localization

Ionut Constandache; Shravan Gaonkar; Matt Sayler; Romit Roy Choudhury; Landon P. Cox

2009-01-01

463

Online Payment for Access to Heterogeneous Mobile Networks1  

Microsoft Academic Search

This paper describes an architecture where access to heterogeneous mobile networks is granted on the basis of online payment methods. Access methods for GSM networks were designed for subscribed post-pay customers. With Intelligent Networks (IN) technology, operators can also offer services to prepay customers. Now online payment might provide additional means for network access. We suggest an IP based architecture

Heiko Knospe; Scarlet Schwiderski-Grosche

2002-01-01

464

Communication  

Microsoft Academic Search

\\u000a Communication impairment is a core deficit associated with autism spectrum disorder (ASD). Therefore, it should not be surprising\\u000a that this topic has become a major thrust of assessment and treatment in applied behavior analysis (ABA). The types of communication\\u000a skills to target for intervention and the behavioral assessment methods that can be used to identify these target behaviors\\u000a are reviewed

Jeff Sigafoos; Mark F. O’Reilly; Giulio E. Lancioni

465

Malicious Actions Against the GPRS Technology Christos Xenakis  

E-print Network

] is a service that provides packet radio access for Global System for Mobile Communications (GSM) users system is built on the GSM infrastructure. However, GPRS is more exposed to intruders compared to GSM and the privacy of users. This architecture is based on the security measures applied to GSM, since the GPRS

Stavrakakis, Ioannis

466

GSM base station electromagnetic radiation and oxidative stress in rats.  

PubMed

The ever increasing use of cellular phones and the increasing number of associated base stations are becoming a widespread source of nonionizing electromagnetic radiation. Some biological effects are likely to occur even at low-level EM fields. In this study, a gigahertz transverse electromagnetic (GTEM) cell was used as an exposure environment for plane wave conditions of far-field free space EM field propagation at the GSM base transceiver station (BTS) frequency of 945 MHz, and effects on oxidative stress in rats were investigated. When EM fields at a power density of 3.67 W/m2 (specific absorption rate = 11.3 mW/kg), which is well below current exposure limits, were applied, MDA (malondialdehyde) level was found to increase and GSH (reduced glutathione) concentration was found to decrease significantly (p < 0.0001). Additionally, there was a less significant (p = 0.0190) increase in SOD (superoxide dismutase) activity under EM exposure. PMID:16954120

Yurekli, Ali Ihsan; Ozkan, Mehmed; Kalkan, Tunaya; Saybasili, Hale; Tuncel, Handan; Atukeren, Pinar; Gumustas, Koray; Seker, Selim

2006-01-01

467

Long-term exposure to microwave radiation provokes cancer growth: evidences from radars and mobile communication systems.  

PubMed

In this review we discuss alarming epidemiological and experimental data on possible carcinogenic effects of long term exposure to low intensity microwave (MW) radiation. Recently, a number of reports revealed that under certain conditions the irradiation by low intensity MW can substantially induce cancer progression in humans and in animal models. The carcinogenic effect of MW irradiation is typically manifested after long term (up to 10 years and more) exposure. Nevertheless, even a year of operation of a powerful base transmitting station for mobile communication reportedly resulted in a dramatic increase of cancer incidence among population living nearby. In addition, model studies in rodents unveiled a significant increase in carcinogenesis after 17-24 months of MW exposure both in tumor-prone and intact animals. To that, such metabolic changes, as overproduction of reactive oxygen species, 8-hydroxi-2-deoxyguanosine formation, or ornithine decarboxylase activation under exposure to low intensity MW confirm a stress impact of this factor on living cells. We also address the issue of standards for assessment of biological effects of irradiation. It is now becoming increasingly evident that assessment of biological effects of non-ionizing radiation based on physical (thermal) approach used in recommendations of current regulatory bodies, including the International Commission on Non-Ionizing Radiation Protection (ICNIRP) Guidelines, requires urgent reevaluation. We conclude that recent data strongly point to the need for re-elaboration of the current safety limits for non-ionizing radiation using recently obtained knowledge. We also emphasize that the everyday exposure of both occupational and general public to MW radiation should be regulated based on a precautionary principles which imply maximum restriction of excessive exposure. PMID:21716201

Yakymenko, I; Sidorik, E; Kyrylenko, S; Chekhun, V

2011-06-01

468

Design of an LTCC switch diplexer front-end module for GSM\\/DCS\\/PCS applications  

Microsoft Academic Search

This paper presents the results of an antenna switch\\/filter module integrating GSM\\/DCS\\/PCS diplexer functions and Rx\\/Tx antenna switching on a low temperature co-fired ceramic (LTCC) substrate. Although the RF front-end module (FEM) was configured for dual-band (GSM\\/DCS) applications, the high pass filter function was designed to operate in the PCS band as well. Harmonic filtering was included in the diplexer

Rodolfo Lucero; W. Qutteneh; A. Pavio; D. Meyers; J. Estes

2001-01-01

469

Communications  

ERIC Educational Resources Information Center

Scholars representing the field of communications were asked to identify what they considered to be the most exciting and imaginative work currently being done in their field, as well as how that work might change our understanding. The scholars included Jeremy Bailenson, Patrice Buzzanell, Stanley Deetz, David Tewksbury, Robert J. Thompson, and…

Bailenson, Jeremy; Buzzanell, Patrice; Deetz, Stanley; Tewksbury, David; Thompson, Robert J.; Turow, Joseph; Bichelmeyer, Barbara; Bishop, M. J.; Gayeski, Diane

2013-01-01

470

Near Field Communication and Health: Turning a Mobile Phone into an Interactive Multipurpose Assistant in Healthcare Scenarios  

NASA Astrophysics Data System (ADS)

In this paper we discuss the introduction of the Near Field Communication (NFC) technology in the management of the assistance operations in the hospitals. NFC is a new short range communication system based on RFID technology.

Benelli, Giuliano; Pozzebon, Alessandro

471

Communication Technologies and their Applications beyond Communication  

Microsoft Academic Search

Wireless communication technologies are pervasive in today's everyday environment. Together with the ever-dropping cost for equipment relying on such technology, this abundance gives rise to a wealth of applications well beyond communication itself. Utilizing communication technologies in the context of mobile sensing seems to be an especially promising approach, as mobile phones and other personal handheld devices provide the capabilities

Simon Mayer

472

47 CFR 95.805 - Permissible communications.  

Code of Federal Regulations, 2010 CFR

...false Permissible communications. 95.805 ...Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED...fixed or mobile communications service to subscribers...consistent with the Commission's rules...

2010-10-01

473

No effects of mobile phone use on cortical auditory change-detection in children: an ERP study.  

PubMed

We investigated the effect of mobile phone use on the auditory sensory memory in children. Auditory event-related potentials (ERPs), P1, N2, mismatch negativity (MMN), and P3a, were recorded from 17 children, aged 11-12 years, in the recently developed multi-feature paradigm. This paradigm allows one to determine the neural change-detection profile consisting of several different types of acoustic changes. During the recording, an ordinary GSM (Global System for Mobile Communications) mobile phone emitting 902 MHz (pulsed at 217 Hz) electromagnetic field (EMF) was placed on the ear, over the left or right temporal area (SAR(1g) = 1.14 W/kg, SAR(10g) = 0.82 W/kg, peak value = 1.21 W/kg). The EMF was either on or off in a single-blind manner. We found that a short exposure (two 6 min blocks for each side) to mobile phone EMF has no statistically significant effects on the neural change-detection profile measured with the MMN. Furthermore, the multi-feature paradigm was shown to be well suited for studies of perception accuracy and sensory memory in children. However, it should be noted that the present study only had sufficient statistical power to detect a large effect size. PMID:19771547

Kwon, Myoung Soo; Huotilainen, Minna; Shestakova, Anna; Kujala, Teija; Näätänen, Risto; Hämäläinen, Heikki

2010-04-01

474

A Practical-Time Attack on the A5/3 Cryptosystem Used in Third Generation GSM  

E-print Network

A Practical-Time Attack on the A5/3 Cryptosystem Used in Third Generation GSM Telephony Orr.dunkelman,nathan.keller,adi.shamir}@weizmann.ac.il Abstract. The privacy of most GSM phone conversations is currently protected by the 20+ years old A5 that the changes made by the GSM Association in moving from MISTY to KASUMI resulted in a much weaker cryptosystem

475

Mobile Applications for Participation at the Shopping Mall: Content Analysis and Usability for Persons with Physical Disabilities and Communication or Cognitive Limitations  

PubMed Central

The aim of this exploratory study was to determine the important features in content and usability of existing mobile applications evaluating environmental barriers and facilitators (EBF) to participation for persons with physical disabilities presenting mild communication or cognitive limitations. A rigorous process based on a user-centered design approach led to the identification of two relevant mobile applications to evaluate the EBF. An accessibility expert, the research team as well as five users then tested the mobile applications in a shopping mall. A thematic content analysis of the research team’s and users’ comments established 10 categories of key features that adequately respond to the needs of the clientele targeted in this study. In terms of content, granularity and contextualization of the information provided were considered important. With respect to usability, relevant features were place finding, rating system, presentation of results, compatibility, user-friendliness, aesthetics, credibility of the information as well as connectivity/interactiveness. The research team and the users agreed on some aspects such as aesthetics, but had different perspectives on features such as the rating system or the connectivity/interactiveness of the application. The users proposed new features suggesting that the existing mobile applications did not correspond to all their needs. PMID:25513999

Auger, Claudine; Leduc, Emilie; Labbé, Delphine; Guay, Cassioppée; Fillion, Brigitte; Bottari, Carolina; Swaine, Bonnie

2014-01-01

476

Mobile applications for participation at the shopping mall: content analysis and usability for persons with physical disabilities and communication or cognitive limitations.  

PubMed

The aim of this exploratory study was to determine the important features in content and usability of existing mobile applications evaluating environmental barriers and facilitators (EBF) to participation for persons with physical disabilities presenting mild communication or cognitive limitations. A rigorous process based on a user-centered design approach led to the identification of two relevant mobile applications to evaluate the EBF. An accessibility expert, the research team as well as five users then tested the mobile applications in a shopping mall. A thematic content analysis of the research team's and users' comments established 10 categories of key features that adequately respond to the needs of the clientele targeted in this study. In terms of content, granularity and contextualization of the information provided were considered important. With respect to usability, relevant features were place finding, rating system, presentation of results, compatibility, user-friendliness, aesthetics, credibility of the information as well as connectivity/interactiveness. The research team and the users agreed on some aspects such as aesthetics, but had different perspectives on features such as the rating system or the connectivity/interactiveness of the application. The users proposed new features suggesting that the existing mobile applications did not correspond to all their needs. PMID:25513999

Auger, Claudine; Leduc, Emilie; Labbé, Delphine; Guay, Cassioppée; Fillion, Brigitte; Bottari, Carolina; Swaine, Bonnie

2014-01-01

477

Using a Short-Term Predictive Algorithm to Improve the Communication's Speed in Fast Mobile Ad-Hoc Networks  

E-print Network

-term predictive algorithm. To evaluate the algorithm on fast mobile ad-hoc networks, we developed a microscopic over three different scenarios based on four parameters: Route Discovery (RD) time, End-to-End Delay, the sender needs to initialise a Route Discovery (RD) phase. A deficiency of Mobile Ad-hoc NETwork (MANET

Haddadi, Hamed

478

Mobile Agents - Smart Messages  

Microsoft Academic Search

Wireless communication with Mobile Computing devices is known to be problematic. It is very different in character from conventional communication over wired networks. Since many distributed applications make assumptions about network characteristics, they may not be used in a hostile mobile environment. We are proposing a new kind of messaging system which incorporates adaptive behaviour into the messages themselves. We

Leon Hurst; Pfidraig Cunningham; Fergal Somers

1997-01-01

479

1288 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 49, NO. 7, JULY 2001 Downlink Beamforming for DS-CDMA Mobile  

E-print Network

to be reduced ef- fectively in order to obtain high system capacity. Spatial-divi- sion multiple access (SDMA technique to suppress interferences. The main operations in SDMA include uplink (from mobile station to base

Liu, K. J. Ray

480

Efficacy of communication amongst staff members at plastic and reconstructive surgery section using smartphone and mobile WhatsApp  

PubMed Central

Objective: The objective of this study is to assess the efficacy of smartphone and its WhatsApp application as a communication method amongst the staff of plastic and reconstructive surgery section at tertiary care health facility. Materials and Methods: From January 2012 onwards, the authors used smartphones and its WhatsApp application as a communication method amongst their team for various aspects of patient management and as a tool for academic endorsements. Results: During the period of this study, there were 116 episodes regarding patient management, which were handled, in a timely fashion by using this application. In addition opinion of rotating residents in the section was sought regarding the efficacy of this method of communication. Overall majority of residents were satisfied with this mode of communication. Conclusions: This new method of communication is an effective method for clinical and academic endorsements. The method is cheap and quick and easy to operate. PMID:24459338

Wani, Shabeer Ahmad; Rabah, Sari M.; AlFadil, Sara; Dewanjee, Nancy; Najmi, Yahya

2013-01-01

481

Land Mobile Satellite Service (LMSS) channel simulator: An end-to-end hardware simulation and study of the LMSS communications links  

NASA Technical Reports Server (NTRS)

The design and implementation of the Land Mobile Satellite Service (LMSS) channel simulator as a facility for an end to end hardware simulation of the LMSS communications links, primarily with the mobile terminal is described. A number of studies are reported which show the applications of the channel simulator as a facility for validation and assessment of the LMSS design requirements and capabilities by performing quantitative measurements and qualitative audio evaluations for various link design parameters and channel impairments under simulated LMSS operating conditions. As a first application, the LMSS channel simulator was used in the evaluation of a system based on the voice processing and modulation (e.g., NBFM with 30 kHz of channel spacing and a 2 kHz rms frequency deviation for average talkers) selected for the Bell System's Advanced Mobile Phone Service (AMPS). The various details of the hardware design, qualitative audio evaluation techniques, signal to channel impairment measurement techniques, the justifications for criteria of different parameter selection in regards to the voice processing and modulation methods, and the results of a number of parametric studies are further described.

Salmasi, A. B. (editor); Springett, J. C.; Sumida, J. T.; Richter, P. H.

1984-01-01

482

Autonomous Mobile Networks  

Microsoft Academic Search

Summary form only given, as follows. Autonomous mobile networks are distributed ad-hoc networks of nodes that can sense, actuate, compute and communicate with each other using point-to-point multi-hop communication. The nodes in such networks include static sensors, mobile sensors, robots, and humans. Such systems combine the most advanced concepts in perception, communication and control to create computational systems capable of

Daniela Rus

2004-01-01

483

Wideband BiCMOS VCO for GSM\\/UMTS direct conversion receivers  

Microsoft Academic Search

Summary form only given. With the increasing number of mobile communication standards, a large research effort is put into the task of complete integration of RF voltage-controlled oscillators (VCOs) for multi-band and multi-mode direct conversion transceivers. However, RF VCOs are, at present, not fully integrated in transceivers, since they suffer from poor phase noise and fabrication tolerances. Satisfying the phase

Jakub J. Kucera

2001-01-01

484

2178 IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 33, NO. 12, DECEMBER 1998 A 900-MHz/1.8-GHz CMOS  

E-print Network

technology. Section II of this paper reviews the global system for mobile communication (GSM) and DCS1800 I SYSTEM CHARACTERISTICS OF THE GSM AND DCS1800 WIRELESS STANDARDS Fig. 1. Conceptual example cel- lular standards, namely, GSM and Digital Communication System at 1800 MHz (DCS1800

Razavi, Behzad

485

104 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 3, 2004 GSM/DCS/IMT-2000 Triple-Band Built-In Antenna  

E-print Network

104 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 3, 2004 GSM/DCS/IMT-2000 Triple-Band Built internal antenna which covers GSM/DCS/IMT-2000 bands. The proposed antenna consists of the double shorting features for GSM/DCS/IMT-2000 bands handset applications. Index Terms--Double-crossed C-slot, double

Park, Seong-Ook

486

A dual-band RF front-end for WCDMA and GSM applications  

Microsoft Academic Search

An RF front-end for dual-band, dual-mode operation is presented in this paper. The front-end consumes 22.5 mW from a 1.8 V supply and is designed to be used in direct conversion WCDMA and GSM receivers. The measured noise figure, gain, and IIP3 are 2.3 dB, 39.5 dB, and -19 dBm for GSM and 4.3 dB, 33 dB, and -14.5 dBm

Jussi Ryynanen; Kalle Kivekas; Jarkko Jussila; Aarno Parssinen; Kari Halonen

2000-01-01

487

Built-in multiband antennas for mobile phone and WLAN standards  

Microsoft Academic Search

Two novel miniature multiband antennas suitable for mobile phone and WLAN applications have been presented in this paper. The first antenna achieves low return loss and good efficiency in the GSM and the DCS\\/PCS\\/UMTS bands while the second structure covers the 5 GHz WLAN bands in addition with same performance.

P. Ciais; R. Staraj; G. Kossiavas; C. Luxey

2005-01-01

488

Future mobile networks: ad-hoc access based on online payment with smartcards  

Microsoft Academic Search

This paper describes an architecture where access to heterogeneous mobile networks is granted on the basis of online payment using smartcards. Access methods for GSM networks were designed for subscribed post-pay customers. With IN (intelligent networks) technology, operators could also offer services to prepay customers. Now, online payment might provide additional means for network access. In particular, a smartcard containing

Heiko Knospe; Scarlet Schwiderski-Grosche

2002-01-01

489

Information and Communication Technologies and Social Mobilization: The Case of the Indigenous Movement in Ecuador, 2007-2011  

ERIC Educational Resources Information Center

Over the last three decades Indigenous people in Ecuador have faced government policies threatening their internationally recognized Indigenous human rights. Although a national social movement emerged in Ecuador in 1990, the level of mobilization has since varied. This dissertation project proposes to address the question, under what conditions…

Green-Barber, Lindsay N.

2012-01-01

490

Design of a software defined radio channel simulator for mobile communications: Performance demonstration with DSRC for different vehicle speeds  

Microsoft Academic Search

The reconfiguration scheme and channel algorithms of the software defined radio (SDR) channel simulator is designed for testing the base band transceiver of various mobile radio systems. The flexibility in selecting a combination of waveform and fading channel software modules and setting the system parameters is the main feature of the SDR channel simulator. An example of the SDR channel

Jeich Mar; Ti-Han Lung; You-Rong Lin; Chi-Cheng Kuo

2008-01-01

491

Unlimited or disrupted communication? How does the development of the mobile phone effect our ability of social action?  

Microsoft Academic Search

The aim of this essay is to discuss the thesis of the German Sociologist Günter Burkhart that in modern societies a phenomenon appeared which he calls “handymania”, an excessive and nearly addictive use of the mobile phones especially from adolescents. After a short overview about the history of the cell phone, I will relate this development to Jürgen Habermas “theory

Marie-Sophie Löhlein

2009-01-01

492

Distributed services for mobile ad hoc networks  

E-print Network

A mobile ad hoc network consists of certain nodes that communicate only through wireless medium and can move arbitrarily. The key feature of a mobile ad hoc network is the mobility of the nodes. Because of the mobility, communication links form...

Cao, Guangtong

2005-11-01

493

MOBILIZED BY MOBILE MEDIA HOW CHINESE PEOPLE USE MOBILE PHONES TO CHANGE  

E-print Network

MOBILIZED BY MOBILE MEDIA HOW CHINESE PEOPLE USE MOBILE PHONES TO CHANGE POLITICS AND DEMOCRACY Jun of "guanxi-embedded mobile social network"; to Toke Nordbo from the PhD school at the Faculty of Humanities at the Department of Media, Cognition and Communication in University of Copenhagen. I am indebted to both

Paris-Sud XI, Université de

494

Evaluation of selected biochemical parameters in the saliva of young males using mobile phones.  

PubMed

Abstract The biochemical status in the saliva of 12 males before/after using mobile phone has been evaluated. Radio frequency signals of 1800 MHz (continuous wave transmission, 217?Hz modulate and Global System for Mobile Communications [GSM - non-DTX]) with 1.09 w/kg specific absorption rate (SAR) value were used for 15 and 30?min. Cell phone radiation induced a significant increase of superoxide dismutase (SOD); there was a statistically significant effect of talking time on the levels of SOD, F(2, 33)?=?8.084, p?

Abu Khadra, Khalid M; Khalil, Ahmad M; Abu Samak, Mahmoud; Aljaberi, Ahmad

2015-03-01

495

47 CFR 80.1185 - Supplemental eligibility for mobile-satellite stations.  

Code of Federal Regulations, 2012 CFR

...eligibility for mobile-satellite stations. 80...Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED...Installations Mobile-Satellite Stations § 80...proposing to furnish satellite communication services on...

2012-10-01

496

47 CFR 80.1185 - Supplemental eligibility for mobile-satellite stations.  

Code of Federal Regulations, 2010 CFR

...eligibility for mobile-satellite stations. 80...Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED...Installations Mobile-Satellite Stations § 80...proposing to furnish satellite communication services on...

2010-10-01

497

47 CFR 80.1185 - Supplemental eligibility for mobile-satellite stations.  

Code of Federal Regulations, 2013 CFR

...eligibility for mobile-satellite stations. 80...Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED...Installations Mobile-Satellite Stations § 80...proposing to furnish satellite communication services on...

2013-10-01

498

47 CFR 80.1185 - Supplemental eligibility for mobile-satellite stations.  

Code of Federal Regulations, 2011 CFR

...eligibility for mobile-satellite stations. 80...Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED...Installations Mobile-Satellite Stations § 80...proposing to furnish satellite communication services on...

2011-10-01

499

A lossy, dictionary-based method for short message service (SMS) text compression.  

E-print Network

??Includes abstract. Keywords: SMS, text compression, lossy compression, dictionary compression The Global System for Mobile communications (GSM) specification suggests that untrained Huffman encoding is the… (more)

Martin, Wickus.

2009-01-01

500

A fully programmable prototype for the experimentation of the SDMA concept and use of smart antennas for UMTS and GSM\\/DCS1800 networks  

Microsoft Academic Search

This paper describes the development and the first results obtained by Thomson-CSF Communications with a fully programmable prototype for an evaluation of the spatial division multiple access (SDMA) concept and the use of smart antennas. The growing demand for mobile communications requires the use of new advanced technologies which can enhance the capacity of radio communication networks. Among these techniques,

Jean-Jacques MONOT; J. Thibault; Pascal CHEVALIER; Frangois PIPON; Sylvie MAYRARGUE; Armand LEVY

1997-01-01