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1

GSM: Global System for Mobile communications  

E-print Network

GSM: Global System for Mobile communications Marco Moretti Università di Pisa #12;Sommario Introduzione Architettura di rete Tecnologia radio Canali GSM Procedure #12;Introduzione #12;Introduzione GSM è a livello Europeo GSM nasce come open standard architecure (OSA), seguendo il modello di Internet. Non è uno

Abrardo, Andrea

2

Overview of GSM: The Global System for Mobile Communications John Scourias  

E-print Network

Overview of GSM: The Global System for Mobile Communications John Scourias University of Waterloo jscourias@neumann.uwaterloo.ca March 13, 1996 1 History of GSM During the early 1980s, analog cellular of European Posts and Telegraphs (CEPT) formed a study group called the Groupe Special Mobile (GSM) to study

Waterloo, University of

3

GSM Mobile Phone Based Communication of Multimedia Information : A Case Study Through a practical application, this paper studies the capacity of the GSM network, a wireless mobile phone network  

E-print Network

Title: GSM Mobile Phone Based Communication of Multimedia Information : A Case Study Abstract: Through a practical application, this paper studies the capacity of the GSM network, a wireless mobile the GSM network. The design and construction of the system are described with parameters of the equipment

Wong, Kenneth K.Y.

4

GSM-PKI solution enabling secure mobile communications.  

PubMed

Because of its wide distribution and ease of use, the mobile phone, as a reliable personal communications channel, offers an excellent basis for the provision of reliable electronic communications services. In Finland, ca. 75% of the citizens have a mobile phone and, at present and most likely also in the future, it is the most widely spread service channel allowing reliable electronic communications. Despite the restricted functions of the mobile phone, the citizens can use the phone also as a communications medium. In 2001, the Finns sent over 1 billion SMS messages. In Finland, TeliaSonera Finland Oyi and the Population Register Centre (PRC) have closed a co-operation agreement with the aim of creating a mobile phone service for the electronic identification of a person. The co-operation launched is a significant development project from the perspective of the citizens. As a result, the consumers will have a new alternative for reliable electronic communications and commerce in data networks in addition to the electronic identification card. In the future, it will be possible to use the services of both public administration and the private sector by means of a mobile phone more reliably than before, without a physical visit, e.g. to a health centre or to another provider of healthcare services. The possibility of identification and signature by a mobile phone allows an easier provision of versatile services irrespective of time and place, because, in addition to voice, text message, and WAP functions, the service can be utilised also in communications services through the Internet, in which case, the mobile phone acts like a card reader. From the perspective of reliable personal mobile communications, the healthcare sector is one of the most significant and challenging application areas. PMID:15066565

Jelekinen, Pekka

2004-03-31

5

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

6

An Electronic Voting System Using GSM Mobile Technology  

E-print Network

An Electronic Voting System Using GSM Mobile Technology Yang Feng, Siaw-Lynn Ng and Scarlet and trans- parent way. On the other hand, GSM (Global System for Mobile commu- nications) is the most widely used mobile networking standard. There are more than one billion GSM users worldwide that represent

Dent, Alexander W.

7

International Journal of Digital Evidence Spring 2003, Volume 2, Issue 1 Forensics and the GSM mobile telephone system  

E-print Network

International Journal of Digital Evidence Spring 2003, Volume 2, Issue 1 Forensics and the GSM AS Abstract The GSM system has become the most popular system for mobile communication in the world. Criminals commonly use GSM phones, and it is therefore a need for forensic investigators to understand which evidence

Almulhem, Ahmad

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

A communication architecture to access data services through GSM  

E-print Network

A communication architecture to access data services through GSM J.M. Rivadeneyra Sicilia and J present a communication architecture for accessing TCP/IP networks (mainly Internet) through GSM. We features of wireless links and GSM networks. Our proposal is based in the indirect model of client

Miguel-Alonso, José

10

A GSM mobile system to monitor brain function using a near-infrared light sensor  

Microsoft Academic Search

This paper presents a versatile mobile system to monitor oxygenated hemoglobin (HBO) and deoxygenated hemoglobin (HB) concentration changes in brain and tissues. The system uses global system for mobile communications (GSM) and Bluetooth networks to provide extended mobility. The system consists of three parts: a wireless near-infrared light sensor with Bluetooth support, a personal digital assistant (PDA) and a personal

Salah Sharieh; Alexander Ferworn; Vladislav Toronov

2008-01-01

11

Inter-system mobility and service management in GSM\\/PDC roaming  

Microsoft Academic Search

This paper discusses mobility support and service portability between different mobile systems. The IWF (interworking function), which deals with signaling protocol and user information conversion, is a promising approach for inter-system roaming. The required capabilities, configuration and procedures are described for the case of GSM (Global System for Mobile communications) and PDC (Personal Digital Cellular). The paper concludes that the

Akira Yamaguchi; Shinji Ota; Yoshihiko Ito; Masayoshi Ohashi; Fumio Watanabe

1997-01-01

12

Implications of Unlicensed Mobile Access (UMA) for GSM security  

Microsoft Academic Search

Despite its imperfections, GSM security has stood well the test of time. In part, this security success has relied on closed platforms that prevent the end-user from tampering with the GSM protocol stacks. While it is possible to build phones that do not have such restrictions, this is difficult due to, e.g., legislation and technical complexity. Unlicensed Mobile Access (UMA)

Sandro Grech; P. Eronen

2005-01-01

13

Title: GSM security Vulnerability Members: Pacharawit Topark-Ngarm  

E-print Network

Title: GSM security Vulnerability Members: Pacharawit Topark-Ngarm Panupat Poocharoen Abstract Global System for Mobile communications (GSM system) has become the most popular standard for digital cellular communication. The GSM security system depends on encryption

14

GSM Technology as a Communication Media for an Autonomous Unmanned Aerial Vehicle GSM Technology as a Communication Media for an  

E-print Network

GSM Technology as a Communication Media for an Autonomous Unmanned Aerial Vehicle GSM Technology as a Communication Media for an Autonomous Unmanned Aerial Vehicle Mariusz Wzorek, David Landen, Patrick Doherty,davla,patdo}@ida.liu.se ABSTRACT Unmanned Aerial Vehicles (UAVs) are becoming more reliable, autonomous and easier to use

Doherty, Patrick

15

Experimental and numerical assessment of low-frequency current distributions from UMTS and GSM mobile phones.  

PubMed

The evaluation of the exposure from mobile communication devices requires consideration of electromagnetic fields (EMFs) over a broad frequency range from dc to GHz. Mobile phones in operation have prominent spectral components in the low-frequency (LF) and radio-frequency (RF) ranges. While the exposure to RF fields from mobile phones has been comprehensively assessed in the past, the LF fields have received much less attention. In this study, LF fields from mobile phones are assessed experimentally and numerically for the global system for mobile (GSM) and universal mobile telecommunications system (UMTS) communication systems and conclusions about the global (LF and RF) EMF exposure from both systems are drawn. From the measurements of the time-domain magnetic fields, it was found that the contribution from the audio signal at a normal speech level, i.e., -16 dBm0, is the same order of magnitude as the fields induced by the current bursts generated from the implementation of the GSM communication system at maximum RF output level. The B-field induced by currents in phones using the UMTS is two orders of magnitude lower than that induced by GSM. Knowing that the RF exposure from the UMTS is also two orders of magnitude lower than from GSM, it is now possible to state that there is an overall reduction of the exposure from this communication system. PMID:24216774

Gosselin, Marie-Christine; Khn, Sven; Kuster, Niels

2013-12-01

16

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

Microsoft Academic Search

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

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

2008-01-01

17

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

18

ROBUST SPEECH RECOGNITION FOR MULTIPLE TOPOLOGICAL SCENARIOS OF THE GSM MOBILE PHONE  

E-print Network

ROBUST SPEECH RECOGNITION FOR MULTIPLE TOPOLOGICAL SCENARIOS OF THE GSM MOBILE PHONE SYSTEM : {thsalon,vas}@telecom.tuc.gr ABSTRACT This paper deals with robust speech recognition in the GSM mobile environment. Our focus is on the voice degradation due to the losses in the GSM coding scheme. Thus, we

19

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

20

Assessment of extremely low frequency magnetic field exposure from GSM mobile phones.  

PubMed

Although radio frequency (RF) electromagnetic fields emitted by mobile phones have received much attention, relatively little is known about the extremely low frequency (ELF) magnetic fields emitted by phones. This paper summarises ELF magnetic flux density measurements on global system for mobile communications (GSM) mobile phones, conducted as part of the MOBI-KIDS epidemiological study. The main challenge is to identify a small number of generic phone models that can be used to classify the ELF exposure for the different phones reported in the study. Two-dimensional magnetic flux density measurements were performed on 47 GSM mobile phones at a distance of 25?mm. Maximum resultant magnetic flux density values at 217?Hz had a geometric mean of 221 (+198/-104)?nT. Taking into account harmonic data, measurements suggest that mobile phones could make a substantial contribution to ELF exposure in the general population. The maximum values and easily available variables were poorly correlated. However, three groups could be defined on the basis of field pattern indicating that manufacturers and shapes of mobile phones may be the important parameters linked to the spatial characteristics of the magnetic field, and the categorization of ELF magnetic field exposure for GSM phones in the MOBI-KIDS study may be achievable on the basis of a small number of representative phones. Such categorization would result in a twofold exposure gradient between high and low exposure based on type of phone used, although there was overlap in the grouping. PMID:24203762

Caldern, Carolina; Addison, Darren; Mee, Terry; Findlay, Richard; Maslanyj, Myron; Conil, Emmanuelle; Kromhout, Hans; Lee, Ae-kyoung; Sim, Malcolm R; Taki, Masao; Varsier, Nadge; Wiart, Joe; Cardis, Elisabeth

2014-04-01

21

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

22

Mobile data communications in Germany-a survey  

Microsoft Academic Search

Mobile radio systems for data communications in Germany and their state of introduction are described. Some application-areas and related systems are addressed e.g. the cellular Global System for Mobile Communication (GSM), trunked cellular packet radio by Modacom and ETSI-TETRA, radio paging ERMES, cordless telecommunication according to ETSI\\/DECT, mobile satellite radio, and wireless LANs

Bernhard H. Walke

1994-01-01

23

Effect of long-term (2 years) exposure of mouse brains to global system for mobile communication (GSM) radiofrequency fields on astrocytic immunoreactivity.  

PubMed

This study was designed to determine whether long-term (2 years) brain exposure to mobile telephone radiofrequency (RF) fields produces any astrocytic activation as these glia react to a wide range of neural perturbations by astrogliosis. Using a purpose-designed exposure system at 900?MHz, mice were given a single, far-field whole body exposure at a specific absorption rate of 4?W/kg on five successive days per week for 104 weeks. Control mice were sham-exposed or freely mobile in a cage to control any stress caused by immobilization in the exposure module. Brains were perfusion-fixed with 4% paraformaldehyde and three coronal levels immunostained for glial fibrillary acidic protein (GFAP). These brain slices were then examined by light microscopy and the amount of this immunomarker quantified using a color deconvolution method. There was no change in astrocytic GFAP immunostaining in brains after long-term exposure to mobile telephony microwaves compared to control (sham-exposed or freely moving caged mice). It was concluded that long-term (2 years) exposure of murine brains to mobile telephone RF fields did not produce any astrocytic reaction (astrogliosis) detectable by GFAP immunostaining. Bioelectromagnetics. 36:245-250, 2015. 2015 Wiley Periodicals, Inc. PMID:25703451

Court-Kowalski, Stefan; Finnie, John W; Manavis, Jim; Blumbergs, Peter C; Helps, Stephen C; Vink, Robert

2015-04-01

24

A PCS Based Architecture for Tactical Mobile Communications Erdal Cayirci Cem Ersoy  

E-print Network

Subsystem (LAS), the Mobile Subsystem (MS) and the system management and control subsystem. Among in the second generation systems like Global System for Mobile Communications (GSM) which are digital cellular Institute (ETSI) is developing Universal Mobile Telecommunications System (UMTS) which will replace GSM

25

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

26

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

27

Microwaves from UMTS/GSM mobile phones induce long-lasting inhibition of 53BP1/gamma-H2AX DNA repair foci in human lymphocytes.  

PubMed

We have recently described frequency-dependent effects of mobile phone microwaves (MWs) of global system for mobile communication (GSM) on human lymphocytes from persons reporting hypersensitivity to electromagnetic fields and healthy persons. Contrary to GSM, universal global telecommunications system (UMTS) mobile phones emit wide-band MW signals. Hypothetically, UMTS MWs may result in higher biological effects compared to GSM signal because of eventual "effective" frequencies within the wideband. Here, we report for the first time that UMTS MWs affect chromatin and inhibit formation of DNA double-strand breaks co-localizing 53BP1/gamma-H2AX DNA repair foci in human lymphocytes from hypersensitive and healthy persons and confirm that effects of GSM MWs depend on carrier frequency. Remarkably, the effects of MWs on 53BP1/gamma-H2AX foci persisted up to 72 h following exposure of cells, even longer than the stress response following heat shock. The data are in line with the hypothesis that the type of signal, UMTS MWs, may have higher biological efficiency and possibly larger health risk effects compared to GSM radiation emissions. No significant differences in effects between groups of healthy and hypersensitive subjects were observed, except for the effects of UMTS MWs and GSM-915 MHz MWs on the formation of the DNA repair foci, which were different for hypersensitive (P < 0.02[53BP1]//0.01[gamma-H2AX]) but not for control subjects (P > 0.05). The non-parametric statistics used here did not indicate specificity of the differences revealed between the effects of GSM and UMTS MWs on cells from hypersensitive subjects and more data are needed to study the nature of these differences. PMID:18839414

Belyaev, Igor Y; Markov, Eva; Hillert, Lena; Malmgren, Lars O G; Persson, Bertil R R

2009-02-01

28

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; Knnl, Sami; Laine, Matti; Rinne, Juha O; Toivonen, Tommi; Johansson, Jarkko; Ters, Mika; Lindholm, Harri; Alanko, Tommi; Hmlinen, Heikki

2011-01-01

29

GSM mobile phone radiation suppresses brain glucose metabolism.  

PubMed

We investigated the effects of mobile phone radiation on cerebral glucose metabolism using high-resolution positron emission tomography (PET) with the (18)F-deoxyglucose (FDG) tracer. A long half-life (109 minutes) of the (18)F 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. (18)F-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; Knnl, Sami; Laine, Matti; Rinne, Juha O; Toivonen, Tommi; Johansson, Jarkko; Ters, Mika; Lindholm, Harri; Alanko, Tommi; Hmlinen, Heikki

2011-12-01

30

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

31

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

32

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

33

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

34

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 16, NO. 9, DECEMBER 1998 1785 Decision Feedback Sequence Estimation  

E-print Network

such as the global system for mobile communication (GSM) system. In such conditions, it is desirable to use for nonminimum phase channels. In the global system for mobile communication (GSM) system, training sequences

35

No effects of short-term GSM mobile phone radiation on cerebral blood flow measured using positron emission tomography.  

PubMed

The present study investigated the effects of 902.4 MHz global system for mobile communications (GSM) mobile phone radiation on cerebral blood flow using positron emission tomography (PET) with the (15) O-water tracer. Fifteen young, healthy, right-handed male subjects were exposed to phone radiation from three different locations (left ear, right ear, forehead) and to sham exposure to test for possible exposure effects on brain regions close to the exposure source. Whole-brain [?O]H?O-PET images were acquired 12 times, 3 for each condition, in a counterbalanced order. Subjects were exposed for 5 min in each scan while performing a simple visual vigilance task. Temperature was also measured in the head region (forehead, eyes, cheeks, ear canals) during exposure. The exposure induced a slight temperature rise in the ear canals but did not affect brain hemodynamics and task performance. The results provided no evidence for acute effects of short-term mobile phone radiation on cerebral blood flow. PMID:21932437

Kwon, Myoung Soo; Vorobyev, Victor; Knnl, Sami; Laine, Matti; Rinne, Juha O; Toivonen, Tommi; Johansson, Jarkko; Ters, Mika; Joutsa, Juho; Tuominen, Lauri; Lindholm, Harri; Alanko, Tommi; Hmlinen, Heikki

2012-04-01

36

Effects of exposure to electromagnetic fields emitted by GSM 900 and WCDMA mobile phones on cognitive function in young male subjects.  

PubMed

Results of studies on the possible effects of electromagnetic fields emitted by mobile phones on cognitive functions are contradictory, therefore, possible effects of long-term (7?h?15?min) electromagnetic field (EMF) exposure to handset-like signals of Global System for Mobile Communications (GSM) 900 and Wideband Code-Division Multiple Access (WCDMA) on attention and working memory were studied. The sample comprised 30 healthy male subjects (mean??SD: 25.3??2.6?years), who were tested on nine study days in which they were exposed to three exposure conditions (sham, GSM 900 and WCDMA) in a randomly assigned and balanced order. All tests were presented twice (morning and afternoon) on each study day within a fixed timeframe. Univariate comparisons revealed significant changes when subjects were exposed to GSM 900 compared to sham, only in the vigilance test. In the WCDMA exposure condition, one parameter in the vigilance and one in the test on divided attention were altered compared to sham. Performance in the selective attention test and the n-back task was not affected by GSM 900 or WCDMA exposure. Time-of-day effects were evident for the tests on divided and selective attention, as well as for working memory. After correction for multiple testing, only time-of-day effects remained significant in two tests, resulting in faster reactions in the afternoon trials. The results of the present study do not provide any evidence of an EMF effect on human cognition, but they underline the necessity to control for time of day. PMID:21365662

Sauter, Cornelia; Dorn, Hans; Bahr, Achim; Hansen, Marie-Luise; Peter, Anita; Bajbouj, Malek; Danker-Hopfe, Heidi

2011-04-01

37

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

38

SINGULAR VALUE ANALYSIS OF SPACE-TIME EQUALIZATION IN THE GSM MOBILE SYSTEM Alle-Jan van der Veen and A. Paulraj  

E-print Network

SINGULAR VALUE ANALYSIS OF SPACE-TIME EQUALIZATION IN THE GSM MOBILE SYSTEM Alle-Jan van der Veen, The Netherlands Stanford University, Information Systems Laboratory, Stanford, CA 94305 Singular value analysis of a GMSK-modulated signal such as em- ployed by GSM reveals that it admits a reasonably accurate linear

van der Veen, Alle-Jan

39

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

40

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

41

An antenna switch module for GSM application using LTCC technology  

Microsoft Academic Search

An antenna switch module using PIN (P region-I region-N region) diode for GSM (Global System for Mobile communications) application has been designed and fabricated. By taking advantage of three-dimensional integration of the LTCC (low-temperature co-fired ceramic) substrate and through a novel design of miniature lumped-element realization of transmission line, the size of proposed GSM switch is 7.64mm 4.20mm

Xiao-Chuan Hong; Hong-Li Peng; Jun-Fa Mao

2010-01-01

42

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

43

Improving the efficiency of measurement procedures for assessing human exposure in the vicinity of mobile phone (GSM/DCS/UMTS) base stations.  

PubMed

Standards stipulate 6-min time interval of averaging for measurements of radio-frequency electromagnetic fields to assess human exposure to non-ionising radiation. Having in mind the base stations of public land mobile systems, the time interval defined in such a way noticeably limits the number of measuring points in practical applications. In this paper, based on the results of measurements in the vicinity of a multisystem base station (Global System for Mobile Communications [GSM], Digital Communication System [DCS] and Universal Mobile Telecommunications System [UMTS]), it was shown that the measurement process can be significantly accelerated by using shorter time intervals of averaging--15 s, 30 s and 1 min. It was found that measurement results differed from the 6-min root-mean-square mean by 10.5 %, 15.9 and 19 %, respectively, while the uncertainty of the measurements was increased by 3.0 %, 3.8 and 4.4 %, respectively. Shorter time-averaging intervals would reduce the total duration of the exposure assessment survey, while not compromising too much on measurement quality. PMID:21778156

Neskovic, N; Koprivica, M; Neskovic, A; Paunovic, G

2012-04-01

44

Medical reliable network using concatenated channel codes through GSM network.  

PubMed

Although the 4(th) generation (4G) of global mobile communication network, i.e. Long Term Evolution (LTE) coexisting with the 3(rd) generation (3G) has successfully started; the 2(nd) generation (2G), i.e. Global System for Mobile communication (GSM) still playing an important role in many developing countries. Without any other reliable network infrastructure, GSM can be applied for tele-monitoring applications, where high mobility and low cost are necessary. A core objective of this paper is to introduce the design of a more reliable and dependable Medical Network Channel Code system (MNCC) through GSM Network. MNCC design based on simple concatenated channel code, which is cascade of an inner code (GSM) and an extra outer code (Convolution Code) in order to protect medical data more robust against channel errors than other data using the existing GSM network. In this paper, the MNCC system will provide Bit Error Rate (BER) equivalent to the BER for medical tele monitoring of physiological signals, which is 10(-5) or less. The performance of the MNCC has been proven and investigated using computer simulations under different channels condition such as, Additive White Gaussian Noise (AWGN), Rayleigh noise and burst noise. Generally the MNCC system has been providing better performance as compared to GSM. PMID:24110797

Ahmed, Emtithal; Kohno, Ryuji

2013-01-01

45

Nonthermal GSM microwaves affect chromatin conformation in human lymphocytes similar to heat shock  

Microsoft Academic Search

Here we investigated whether microwaves (MWs) of Global System for Mobile Communication (GSM) induce changes in chromatin conformation in human lymphocytes. Effects of MWs were studied at different frequencies in the range of 895-915 MHz in experiments with lymphocytes from seven healthy persons. Exposure was performed in transverse electromagnetic transmission line cell (TEM-cell) using a GSM test-mobile phone. All standard

Ruslan Sarimov; L. O. G. Malmgren; E. Markova; B. R. R. Persson; I. Y. Belyaev

2004-01-01

46

On fundamental concept of mobility for mobile communications  

Microsoft Academic Search

The tremendous demands from the social market are pushing the booming development of mobile communications faster than ever before, leading to the emergence of many new advanced techniques. Mobile communications are changing life styles in many ways. Behind the scenario, the outstanding characteristic that makes this reality is mobility. The paper studies the basic concepts of mobility for mobile communications,

Jun-Zhao Sun; Jaakko Sauvola

2002-01-01

47

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.

48

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

NASA Technical Reports Server (NTRS)

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.

1993-01-01

49

Mobile Communication: The Misunderstood User  

Microsoft Academic Search

With more than 2 billion users in the world, mobile communication has become a global phenomenon. Growing integration with traditional and new media transformed the traditional mobile device into a small multimedia computer. However, while institutions consider converging technologies as the enabler of an Information Society for All, in which user-citizens self-organize, produce and share knowledge, enterprises still develop services

Giuseppe Lugano; Anna Kmrinen; Tero Heiskainen

50

Female Golden Eagle with GPS-GSM Transmitter  

USGS Multimedia Gallery

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

51

GSM SECURITY II Basar Kasim  

E-print Network

to enhance the GSM security is proposed through the following sections. The Elliptic Curve Cryptography (ECC [20, 21, 22, 23, 24, 25]. 2 New Elliptic Curve Cryptography Protocols for GSM Security As described on the Elliptic Curve Diffie- Hellman key agreement scheme and modified to be used in mobile environments

Ertaull, Levent

52

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

53

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.

54

GSM SECURITY Basar Kasim Levent Ertaul  

E-print Network

GSM SECURITY Basar Kasim Levent Ertaul Department of Electrical & Electronics Engineering consumption by a mobile user. This paper focuses on the security techniques used within the GSM standard. First, current GSM security system vulnerabilities are given. Security evaluations of two new security

Ertaull, Levent

55

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

56

IEEE JOURNAL OF SOLID-STATE CIRCUITS, VOL. 43, NO. 12, DECEMBER 2008 2747 A Fully-Integrated Quad-Band GSM/GPRS  

E-print Network

- tributed active transformer (DAT), global system for mobile communications (GSM), power control-Band GSM/GPRS CMOS Power Amplifier Ichiro Aoki, Member, IEEE, Scott Kee, Member, IEEE, Rahul Magoon, Member on the same silicon die. The PA integrates on-chip closed- loop power control and operates under supply

Hajimiri, Ali

57

1. Final Title SECURITY of MOBILE COMMUNICATIONS  

E-print Network

1. Final Title SECURITY of MOBILE COMMUNICATIONS By Noureddine Boudriga Professor at the University of Carthage, Tunisia 2. Summary Mobile communications offer wireless connectivity that enables mobility the growing development of mobile communications more rapidly than ever before. Consequently, a large set

58

Mobile Communication Via Satellite  

NASA Technical Reports Server (NTRS)

System mixes real-time and delayed-transmission channels. Combination of L-band and SHF links connect fixed and mobile equipment on ground to satellite relay. Software and hardware architecture conforms structure of open-system-interconnection model suggested by International Standards Organization.

Yan, Tsun-Yee; Naderi, Firouz M.

1988-01-01

59

Emerging mobile and personal communication systems  

Microsoft Academic Search

The market demand for wireless communications has been demonstrated by the rapid growth of different second-generation wireless technologies that are optimized for particular applications and environments. Obvious examples include: digital cellular systems like GSM, ADC, PDC,and DCS1800 for widespread vehicular and pedestrian services, and cordless telecommunication systems based on CT2, DECT, and PHS standards for residential, business, and public cordless

Raj Pandya

1995-01-01

60

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

61

Communication and Mobility Control in Boxed Ambients  

E-print Network

Communication and Mobility Control in Boxed Ambients Michele Bugliesi Dipartimento di Informatica of Informatics, University of Sussex Abstract Boxed Ambients (BA) replace Mobile Ambients' open capability with communi- cation primitives acting across ambient boundaries. The expressiveness of the new communication

Bugliesi, Michele

62

Mobile Communication Device (MCD) Justification Form  

E-print Network

Mobile Communication Device (MCD) Justification Form This form is required to initiate and re-paid allowance for business use of their personal mobile communication device (MCD); or, to receive a university

63

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

Dyer, Bill

64

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

65

Control Freaks How Online and Mobile Communication  

E-print Network

Control Freaks How Online and Mobile Communication is Reshaping Social Contact Language in New-Truths about Online/Mobile Language: Emoticons (= smileys) Myths Online communication is inherently prone (smiley, frowny, winky) are now common As online/mobile communication becomes commonplace, we feel less

Lansky, Joshua

66

Les interfaces intelligentes et les communications mobiles  

E-print Network

Chapitre 7 Les interfaces intelligentes et les communications mobiles Badr Benmammar Laboratoire'agit du domaine des communications mobiles. Ce domaine demande une expertise spécifique couvrant plusieurs gestion de ressources radio et de la mobilité. Les communications mobiles est un domaine en plein

Paris-Sud XI, Université de

67

Mobile Netw Appl (2012) 17:143151 DOI 10.1007/s11036-011-0297-3  

E-print Network

rate. The channel properties will change very quickly, which prevent the fast power control in WCDMA above. Markus [2] outlines the concept of a GSM-based communication system for high-speed Railway (GSM-R) and proposes to make some modifications to the standard GSM system. A #12;144 Mobile Netw Appl (2012) 17

Liu, Jiangchuan (JC)

68

Lightning and Surge Voltage Protection in Mobile Phone Stations-Practical Experiences with a German Operator  

Microsoft Academic Search

In order to pay off the high investments in licenses and technology for mobile communication networks (GSM, GSM-R, UMTS\\/3G, TETRA, CDMA) in time as short as possible, a fast and safe network system is necessary. Especially in the field of mobile communications, highest demand are made on the continuous availability of sending and receiving systems. The network based on the

Ralf Bibmeier

2005-01-01

69

Awareness of Hazards and Use of GSM Mobile Phone among Non Commercial Drivers in Ilorin, Nigeria  

Microsoft Academic Search

Background: Driver distractions have been suggested as a contributor to traffic accidents. Results indicate that the accident risk can increase when a driver is using the mobile telephone in a car. This study was conducted to determine use of mobile phone by non-commercial drivers and their awareness and attitude to the related risks. Method: This is a descriptive survey. Two-hundred

T. M. Akande; M. S. Ajao

2006-01-01

70

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

PubMed

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

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

2009-08-01

71

Personal mobile communications in microwave band  

Microsoft Academic Search

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

Yuji Kitahara

1993-01-01

72

Communication and Mobility Control in Boxed Ambients  

E-print Network

Communication and Mobility Control in Boxed Ambients Michele Bugliesi Universit`a "Ca' Foscari Sassone University of Sussex Abstract Boxed Ambients (BA) replace Mobile Ambients' open capability with communication primitives acting across ambient boundaries. The expressiveness of the new model of communication

Merro, Massimo

73

Mobile Communications Device Allowances Frequently Asked Questions  

E-print Network

Mobile Communications Device Allowances Frequently Asked Questions Q: Why is NC State University-saving measure and to provide more flexibility for employees who must carry a mobile communications device/Smart phone that uses Active Sync in order to communicate with our e-mail server. Many carriers require data

74

Assessment of real exposure to GSM mobile telephones using the SYRPOM.  

PubMed

A mobile telephone user's exposure to the radio-frequency electromagnetic field depends heavily on the power their telephone radiates, which can vary widely according to requests from the base station. This study presents the design and development of a system called SYstem for Radiated POwer Measurement (SYRPOM), which measures the power radiated by a mobile telephone. This study also describes the tests carried out on the system itself and gives the results of two measuring campaigns it has been possible to perform in this way. The first such campaign consisted of assessing the mean power received by a typical mobile telephone user carrying out various activities. The second campaign was aimed at (1) comparing the mean radiated power when stationary and when moving and (2) assessing and contrasting different models of handsets in terms of the mean radiated power. The SYRPOM has proved to be a flexible, easy-to-use high-performance and innovative tool for carrying out this kind of studies. PMID:23685535

Picard, Dominique; Fouquet, Luce; Chauvin, Sbastien

2013-11-01

75

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

76

Dosimetry in the human head for two types of mobile phone antennas at GSM frequencies  

NASA Astrophysics Data System (ADS)

In this paper, a comparative study of dipole and patch antennas commonly used in portable telephones is investigated. The two models antennas are considered working at 900, 1800 and 2450 MHz bands. Thus, we have included different distances between the mobile phone and the human head model. This study shows the effects of electromagnetic waves on the human head model. The objective is to evaluate the SAR in simulation anatomic based model of the human head for different antenna-head distances and in many frequencies. All numerical simulations results are performed using Ansoft HFSS software.

Karli, Radouane; Ammor, Hassan; Terhzaz, Jaouad

2014-03-01

77

Antennas for mobile satellite communications  

NASA Technical Reports Server (NTRS)

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

Huang, John

1991-01-01

78

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 stablishment 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).

Kollr, Martin

2012-05-01

79

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 ora (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 levelsindependently 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

Gmez-Perretta, Claudio; Navarro, Enrique A; Segura, Jaume; Portols, Manuel

2013-01-01

80

Communication Interference in Mobile Boxed Ambients  

E-print Network

Communication Interference in Mobile Boxed Ambients Michele Bugliesi1, Silvia Crafa1, Massimo Merro2, and Vladimiro Sassone3 Abstract. Boxed Ambients (BA) replace Mobile Ambients'open capability with communication primitives acting across ambient boundaries. Expressiveness is achieved at the price

Bugliesi, Michele

81

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

82

Summer 2007 Mobile and Wireless Communications  

E-print Network

Summer 2007 Mobile and Wireless Communications REU Program Summer 2007 Richard S. Wolff, Ph. D of radio · Ship-to-shore communications: early 1900's (SOS from Titanic in 1912) · Extensive use in World #12;Summer 2007 The electronics boom The growth of mobile telephony as compared with other popular

Dyer, Bill

83

Personal Environment Service for Mobile Users Jongtaek Oh  

E-print Network

Personal Environment Service for Mobile Users Jongtaek Oh Dept. Information & Communications The rapid progress of radio communication technologies stimulated the introduction of new mobile, through the use of a SIM (Subscriber Identity Module) card for GSM (Global System for Mobile Communication

Haas, Zygmunt J.

84

MOBILE COMMUNICATIONS AND HOME COMPUTING POLICY Policy Statement  

E-print Network

Page 1 MOBILE COMMUNICATIONS AND HOME COMPUTING POLICY Policy Statement This policy outlines Northwestern University's mobile communications and home computing policy. This policy is based upon (IRS), specifically addressing whether the provision of mobile communication services and devices

Shahriar, Selim

85

Pseudodifferential operators and Banach algebras in mobile communications  

E-print Network

Pseudodifferential operators and Banach algebras in mobile communications Thomas Strohmer to construct numerically efficient equalizers for multicarrier communication systems in a mobile envi- ronment. 1 Introduction Mobile wireless communication is an extremely rapidly growing sector

Strohmer, Thomas

86

Proactive TCP mechanism to improve Handover performance in Mobile Satellite and Terrestrial Networks  

E-print Network

is having strong resemblance to terrestrial GSM (Global System for Mobile communications) at the upper or the nature of multi-radios' communication. This paper aims to improve TCP communication performance in Mobile. Introduction Traditional terrestrial wireless or cellular networks provide mobile communication services

Sanyal, Sugata

87

Statistical characterisation of the EM interferences acting on GSM-R antennas fixed above moving trains  

NASA Astrophysics Data System (ADS)

In order to harmonise the communication systems between the train and the railway control centres over the European territory, a GSM-R (Global System for Mobile communications - Railways) communication network is progressively deployed along the European railway network. However, the GSM-R communications on board high speed trains can be disturbed by the transient electromagnetic (EM) disturbances induced by the sliding contact between the catenary and the pantograph. In order to study the immunity of the embedded GSM-R communication system against these transient electromagnetic disturbances, the transient interferences induced on the GSM-R antennas on board trains, were characterised in terms of time and amplitude parameters. Measurement campaigns were carried out in France to collect a large number of induced EM interferences on GSM-R antennas fixed on the train roof. With the ultimate goal of generating transient noise scenarios representative of those detected by the antennas, and performing immunity tests in laboratory, statistical distributions of the characteristics (rise time, time duration, repetition rate, amplitude) of the transients are presented. This paper presents the different steps of the analysis of the transient disturbances and the generation of the transient EM scenarios. in here

Ben Slimen, N.; Deniau, V.; Rioult, J.; Dudoyer, S.; Baranowski, S.

2009-11-01

88

Tracking mobile users in wireless communications networks  

Microsoft Academic Search

Tracking strategies for mobile wireless networks are studied. A cellular architecture in which base stations that are interconnected by a wired network communicate with mobile units via wireless links is assumed. The cost of utilizing the wireless links for the actual tracking of mobile users is considered. A tracking strategy in which a subset of all base stations is selected

Amotz Bar-Noy; Ilan Kessler

1993-01-01

89

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

90

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

91

Proceedings of the Workshop on Advanced Network and Technology Concepts for Mobile, Micro, and Personal Communications  

NASA Technical Reports Server (NTRS)

The Workshop on Advanced Network and Technology Concepts for Mobile, Micro, and Personal Communications was held at NASA's JPL Laboratory on 30-31 May 1991. It provided a forum for reviewing the development of advanced network and technology concepts for turn-of-the-century telecommunications. The workshop was organized into three main categories: (1) Satellite-Based Networks (L-band, C-band, Ku-band, and Ka-band); (2) Terrestrial-Based Networks (cellular, CT2, PCN, GSM, and other networks); and (3) Hybrid Satellite/Terrestrial Networks. The proceedings contain presentation papers from each of the above categories.

Paul, Lori (editor)

1991-01-01

92

Optimal Algorithms for GSM Viterbi Modules M.Sc. Student  

E-print Network

design of the 3rd-Generation Global System for Mobile communica- tions(GSM 3G) unit's channel codeOptimal Algorithms for GSM Viterbi Modules Kehuai Wu M.Sc. Student at Department of Informatics and Mathematical Modelling Technical University of Denmark #12;#12;Optimal Algorithms for GSM Viterbi Modules #12

93

Making SMIBeamforming Insensitive to the Sampling Timing for GSM Signals  

E-print Network

In the European digital mobile cellular phone system, GSM, Gaussian Minimum Shift Keying (GMSK) is usedMaking SMIBeamforming Insensitive to the Sampling Timing for GSM Signals Erik Lindskog Signal Inversion method (SMI), using an antenna ar ray, is considered for a GSMsignal. The problem of generating

94

Enhancing Security in GSM Chenthurvasan Duraiappan Yuliang Zheng  

E-print Network

Enhancing Security in GSM Chenthurvasan Duraiappan Yuliang Zheng University of Wollongong E-mail: g security system of Global System of Mobile Com- munications (GSM) and proposes a better security sys- tem for GSM. The proposed security system provides an authenticated session key distribution protocol be

Zheng, Yuliang

95

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

96

75 FR 63445 - Vessel Monitoring Systems; Approved Mobile Transmitting Units and Communications Service...  

Federal Register 2010, 2011, 2012, 2013, 2014

...integrated dual model GPS/GSM/GPRS/Iridium Satellite Communicator or a single mode GPS/Iridium Satellite Communicator mounted in the wheelhouse...Faria WatchDog 750VMS has omni-directional Iridium, GPS, and GSM/GPRS antennas,...

2010-10-15

97

76 FR 75523 - Vessel Monitoring Systems; Approved Mobile Transmitting Units and Communications Service...  

Federal Register 2010, 2011, 2012, 2013, 2014

...integrated dual model GPS/GSM/GPRS/Iridium Satellite Communicator or a single mode GPS/Iridium Satellite Communicator mounted in the wheelhouse...Faria WatchDog 750VMS has omni-directional Iridium, GPS, and GSM/GPRS antennas,...

2011-12-02

98

Wireless Communications Systems, I Cellular Telephone System  

E-print Network

Standards 2nd Generation Digital Systems, 2G 1990: Global System for Mobile Comms (GSM) (66% of world at 1.9 GHz for cellular systems IS-95b, IS-95 was modified to provide data services GSM with dataWireless Communications Systems, I Cellular Telephone System US AMPS: Tx: 869-894 MHz, Rx: 824

Cetiner, Bedri A.

99

Mobile Perspectives: On Websites. Mobile Matters--Communication Trumps Technology  

ERIC Educational Resources Information Center

Mobile technology is a favorite discussion topic among senior IT leaders and higher education administrators. Mobile is the future for content delivery. Colleges and universities need to establish a strategy now and make the decisions necessary to take advantage of this communication opportunity. In this article, the author recommends making

Evans, Susan T.

2011-01-01

100

Enabling Access Through Real-Time Sign Language Communication Over Cell Phones  

E-print Network

frame rates based on activity recognition. Our prototype system is able to compress, transmit communication standards. The most widely used of these technologies is called the Global System for Mobile Communications, or GSM. On top of a GSM network, they operate a data network called the General Packet Radio

Cherniavsky, Neva

101

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

102

Challenges for Nomadic Computing: Mobility Management and Wireless Communications  

E-print Network

Challenges for Nomadic Computing: Mobility Management and Wireless Communications Thomas F. La Computing: Mobility Management and Wireless Communications Thomas F. La Porta Krishan K. Sabnani Richard D, and basic communica- tion services in a mobile, sometimes wireless, environment. Nomadic computing

Yener, Aylin

103

Reliable Communication for Highly Mobile Agents  

Microsoft Academic Search

The provision of a reliable communication infrastructure for mobile agents is still an open research issue. The challenge to reliability we address in this work does not come from the possibility of faults, but rather from the mere presence of mobility, which complicates the problem of ensuring the delivery of information even in a fault-free network. For instance, the asynchronous

Amy L. Murphy; Gian Pietro Picco

1999-01-01

104

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

105

Implementation and analysis of integration GSM\\/GPRS modem in a TMS320VC6713 digital signal processor for vehicle location  

Microsoft Academic Search

The rapidly evolving wireless communications environment and 3G, where the standard are constantly created and modified, has given rise to the integration of GPS (Global Positioning System) and GSM (Global System for Mobile Communication). This integration has been widely applied in many disciplines including Intelligent Transportation System (ITS) and Logistic Management to aid the users to locate their vehicles remotely.

H. A. Rahim; R. B. Ahmad; A. S. M. Zain; U. U. Sheikh

2010-01-01

106

CDMA overlay situations for microcellular mobile communications  

Microsoft Academic Search

Direct sequence code division multiple access communications is a promising approach to cellular mobile communications, which operates in an environment characterized by multipath Rician fading. In this paper, the CDMA network is assumed to share common spectrum with a narrowband microwave user. Because of the presence of the narrowband waveform, an interference suppression filter at each CDMA receiver is employed

Jiangzhou Wang; Laurence B. Milstein

1995-01-01

107

Repeated Transmissions In Mobile/Satellite Communications  

NASA Technical Reports Server (NTRS)

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

Yan, Tsun-Yee; Clare, Loren P.

1988-01-01

108

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

109

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

110

Impacts of mobile agent technology on mobile communication system evolution  

Microsoft Academic Search

The development of third-generation mobile communication systems, such as UMTS, should be based on state-of-the-art middleware technologies. Today distributed object technology (DOT), such as OMG's CORBA, has gained considerable acceptance in the telecommunications environment, within the evolution of IN, TMN systems, and also in the context of UMTS design. Another new software technology, mobile agent technology (MAT), is gaining momentum

LARS HAGEN; MARKUS BREUGST

1998-01-01

111

SECURE AUTHENTICATION FOR MOBILE COMMUNICATION OVER THE INTERNET1  

E-print Network

1 SECURE AUTHENTICATION FOR MOBILE COMMUNICATION OVER THE INTERNET1 Irénée Dupré la Tour, Jean) in Darmstadt, Germany [20]. Abstract ­ Mobile communication on the Internet raises more security concerns than are discussed. #12;2 2. MOBILE COMMUNICATION INFRASTRUCTURE 2.1. Mobility In this paper, we refer to different

von Bochmann, Gregor

112

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

113

78 FR 32689 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Portable Electronic Communications Devices, Including Mobile Phones and Components...Portable Electronic Communications Devices, Including Mobile Phones and Components...portable electronic communications devices, including mobile phones and...

2013-05-31

114

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

115

Modeling and analysis of mobility management in mobile communication networks.  

PubMed

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

Baek, Woon Min; Yoon, Ji Hyun; Kim, Chesoong

2014-01-01

116

C. T. Lin, S. P. Shieh / Chain Authentication in Mobile Communication Systems Chain Authentication in Mobile Communication  

E-print Network

C. T. Lin, S. P. Shieh / Chain Authentication in Mobile Communication Systems 1 Chain Authentication in Mobile Communication Systems Chern-Tang Lin, Shiuh-Pyng Shieh Department of Computer Science parties and the confidentiality of communication channels, must be embedded into mobile communication

Shieh, Shiuhpyng Winston

117

Mobile satellite communications for consumers  

NASA Astrophysics Data System (ADS)

The RadioSat system based on MSAT satellites and scheduled for launch in 1994 is described. The RadioSat system will provide integrated communications and navigation services to consumers, including nationwide digital audio broadcasts, data broadcasts, precision navigation, and two-way voice and data communications. Particular attention is given to the MSAT satellite system capabilities and economics. It is concluded that the RadioSat system will be capable of providing a low-cost, highly flexible two-way communications for consumers that can be adapted to various applications.

Noreen, Gary K.

1991-11-01

118

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

119

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

120

Joint Mission and Communication Aware Mobility Control in Mobile Ad-Hoc Networks  

E-print Network

Joint Mission and Communication Aware Mobility Control in Mobile Ad-Hoc Networks Hee-Tae Roh, in this paper, we study a joint mission and communication aware mobility control problem. We formulate to the object of mobility control, i.e., communication quality and mission. Hence, it is important to control

Paris-Sud XI, Université de

121

Providing Seamless Communication in Mobile Wireless Networks  

E-print Network

-mail: fbbakshi,pkrishna,pradhan,vaidyag@cs.tamu.edu Phone: (409) 862-3411 Technical Report TR-96-015y May 1, 1996 communication, incurring heavy network bandwidth usage (multicast based approach), or do not provide any's cell. Each BS is responsible for forwarding data between the mobile user in it's cell, and the wired

Vaidya, Nitin

122

Frontiers of Wireless and Mobile Communications  

E-print Network

software- defined radio (SDR), antenna beam steering and multiple- inputmultiple-output (MIMO), 60-GHz; mobile multimedia; radio access networks; software-defined radio; wireless communication; 3G and 4GFi networks, vehicle- to-vehicle (V2V) systems to embedded sensor and radio- frequency identification (RFID

Mandayam, Narayan

123

Communicating and Mobile Systems: The ?-calculus  

Microsoft Academic Search

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

Robin Milner

1999-01-01

124

Mobile target tracking with communication delays  

Microsoft Academic Search

This paper presents a study of the effects of communication delays on tracking of mobile targets by networked uninhabited autonomous air vehicles (UAVs) using hospitability maps. Target detection is done using surrogate optimization-based search and coordination, and tracking is achieved using a constrained diffusion of probability density on the hospitability maps via solution of the Fokker-Planck equation. Each of the

Shreecharan Kanchanavally; Chunlei Zhang; R. Ordonez; J. Layne

2004-01-01

125

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

126

Laser Communication Between Mobile Platforms  

Microsoft Academic Search

Practical laser communication is impeded by the inherent strict requirements on agile and accurate steering of the laser beam over a wide angular range that are addressed by the pointing, acquisition, and tracking (PAT) system. While the vehicle carrying the optical instrumentation is in motion, a PAT system is required to compensate for the vibrations applied to the optical platform

JOSEF SOFKA; VLADIMIR V. NIKULIN; VICTOR A. SKORMIN; D. H. Hughes; D. J. Legare

2009-01-01

127

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS, VOL. 19, NO. 10, OCTOBER 2001 1825 Guest Editorial  

E-print Network

) wireless systems such as Global System for Mobile communications (GSM), Personal Digital Cellular (PDC consensus that it will rely on Internet protocols and offer bit rates that are an order of magnitude higher

Kleinrock, Leonard

128

Accountable Anonymous Service Usage in Mobile Communication Systems \\Lambda  

E-print Network

Accountable Anonymous Service Usage in Mobile Communication Systems \\Lambda Levente Butty Introduction 1.1 Background Mobile communication systems allow their users to access a large set of traditional to one particular physical location. From a technology perspective, mobile communication systems have

Bencsáth, Boldizsár

129

Lecture Series in Mobile Telecommunications and Networks Wireless Communications  

E-print Network

Lecture Series in Mobile Telecommunications and Networks Wireless Communications: Ideas that Change at the heart of this development, in particular in the field of mobile communications and networking in 1985. In academia, he has pioneered many of the major advances used in mobile communications today

Toh, C-K.

130

Route Optimization for Intra Communication of a Nested Mobile Network  

E-print Network

Route Optimization for Intra Communication of a Nested Mobile Network Sungmin Baek Seoul National to retain the mobility transparency as the NEMO basic support protocol and to reduce the communication cost protocol efficiently supports communication within a nested mobile network. Categories and Subject

131

DCM 2005 Preliminary Version Splitting Mobility and Communication in  

E-print Network

DCM 2005 Preliminary Version Splitting Mobility and Communication in Boxed Ambients Pablo Garralda of the calculus is mainly focused on three objectives: separa- tion of concerns between mobility and communication constructs for communication and mobility. We establish the basic meta-theory of the calculus by proving

Compagnoni, Adriana

132

Autonomous mobile mailbox model for communication cost reduction  

Microsoft Academic Search

This paper presents a cost-reductive communication schema for distributed multiagent environments containing mobile agents. Communication cost reduction is achieved by employing autonomous mobile mailbox as a message-relay system component. Beneficial modes of mobile mailbox behavior are identified under various operational conditions. A mobile mailbox model is proposed and simulation conducted in order to verify its usability

I. Cavrak; A. Stranjak; M. Zagar

2004-01-01

133

Simulation to track 3D location in GSM through NS2 and real life  

E-print Network

In recent times the cost of mobile communication has dropped significantly leading to a dramatic increase in mobile phone usage. The widespread usage has led mobiles to emerge as a strong alternative for other applications one of which is tracking. This has enabled law-enforcing agencies to detect overspeeding vehicles and organizations to keep track its employees. The 3 major ways of tracking being employed presently are (a) via GPS [1] (b) signal attenuation property of a packet [3] and (c) using GSM Network [2]. The initial cost of GPS is very high resulting in low usage whereas (b) needs a very high precision measuring device. The paper presents a GSM-based tracking technique which eliminates the above mentioned overheads, implements it in NS2 and shows the limitations of the real life simulation. An accuracy of 97% was achieved during NS2 simulation which is comparable to the above mentioned alternate methods of tracking.

Gupta, Anand; Bosco, MS Don; Shashidhar, Vinay; 10.5121/jgraphhoc.2010.2103

2010-01-01

134

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

NASA Astrophysics Data System (ADS)

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

Arcidiancono, Antonio

135

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

NASA Technical Reports Server (NTRS)

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

Arcidiancono, Antonio

1990-01-01

136

Mobility and Identity  

Microsoft Academic Search

While identity management systems for the Internet are debated intensively, identity management in mobile applications has\\u000a grown silently over the last 17 years. Technologies, such as the still-growing Global System for Mobile Communication (GSM)\\u000a with its Subscriber Identity Module (SIM) identification infrastructure, are foundations for many new mobile identity management\\u000a related applications and services. This includes location-based services (LBS), offering

Denis Royer; Andr Deuker; Kai Rannenberg

137

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

138

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

139

A device for concurrent, local/remote control of RS232-based devices by GSM/GPRS  

E-print Network

A device for concurrent, local/remote control of RS232-based devices by GSM/GPRS Eloi Ramon computer control and monitoring. In this paper we present a system to allow remote control by GSM-directional communications between a RS232 and the two other ports (RS232 and GSM/GPRS). Keywords -- GSM, GPRS, RS232, serial

Autònoma de Barcelona, Universitat

140

The Role of Innovation Regimes and Policy for Creating Radical Innovations: Comparing Some Aspects of Fuel Cells and Hydrogen Technology Development with the Development of Internet and GSM  

ERIC Educational Resources Information Center

Telegraphy, the distant ancestor of Internet and GSM (Global System for Mobile Communications), was invented by Samuel Morse in 1838. One year later, William Grove invented the fuel cell. Although numerous highly successful innovations stemming from telegraphy may be observed, the development of fuel cells has been insignificant, slow, and erratic

Godoe, Helge

2006-01-01

141

MobileMiner: A Real World Case Study of Data Mining in Mobile Communication  

Microsoft Academic Search

Mobile communication data analysis has been often used as a background application to motivate many data mining problems. However, very few data mining researchers have a chance to see a working data mining system on real mo- bile communication data. In this demo, we showcase our new system MobileMiner on a real mobile communication data set, which presents a case

Tengjiao Wang; Bishan Yang; Jun Gao; Dongqing Yang; Shiwei Tangy; Haoyu Wu; Kedong Liu; Jian Pei

142

A brief Overview of the GSM Radio Interface Thierry Turletti  

E-print Network

A brief Overview of the GSM Radio Interface Thierry Turletti Telemedia Networks and Systems Group to the GSM­900 radio interface. It is not exhaustive and it is restricted to the TraOEc Channel/Full­Rate Speech (TCH/FS). Keywords Base Station, Channel coding, FDMA, GMSK, GSM, Mobile Station, TDMA, Wireless

Turletti, Thierry

143

An improved model for GSM/GPRS/EDGE performance Facultad de Ingenieria, Universidad de la Republica  

E-print Network

. 1. INTRODUCTION Initially, GSM (Global System for Mobile Application, standard developed by 3GPP, 3An improved model for GSM/GPRS/EDGE performance evaluation COPCA Facultad de Ingenier reality. Among them, the GSM/GPRS/EDGE architecture represents without any question the most worldwide

144

PANA/GSM Authentication for Internet Access Paulo S. Pagliusi and Chris J. Mitchell  

E-print Network

PANA/GSM Authentication for Internet Access Paulo S. Pagliusi and Chris J. Mitchell Information the likely future ubiq- uitous mobility access contexts. This article proposes the PANA/GSM authentication of the PANA/GSM proto- col is also provided. This article aims primarily at contributing to the design

Mitchell, Chris

145

Mobile Advertising in Business-to-Business Communications  

Microsoft Academic Search

Mobile advertising allows companies to communicate with their customers directly - anytime and anywhere. So far, mobile advertising has mainly been connected with consumer products. With the help of a literature review and a qualitative case study, this paper takes a novel approach to mobile advertising as part of business-to- business marketing communications. We argue that context-sensitivity, interactivity, exact targetability,

Tiina Takkula; Jaana Thtinen

146

Reliable Communication for Highly Mobile Agents Amy L. Murphy  

E-print Network

Reliable Communication for Highly Mobile Agents Amy L. Murphy Washington University in St. Louis The provision of a reliable communication infras­ tructure for mobile agents is still an open research is­ sue and agent mi­ gration may cause situations where messages forever chase a mobile agent that moves frequently

Picco, Gian Pietro

147

Reliable Communication for Highly Mobile Agents Amy L. Murphy  

E-print Network

Reliable Communication for Highly Mobile Agents Amy L. Murphy Washington University in St. Louis Abstract. The provision of a reliable communication infrastructure for mobile agents is still an open passing and agent migration may cause situations where messages forever chase a mobile agent that moves

Picco, Gian Pietro

148

A study on the service quality of mobile communication industry  

Microsoft Academic Search

A 25-item service quality evaluation index for mobile communication industry is developed based on the index in the present research. By survey and exploratory factor analysis, it is indicated that the mobile service quality index can be classified into five dimensions. Moreover, the service quality of China Mobile Communication Corporation is evaluated based on the survey data. The result indicates

Yongrui Duan; Liqin Sun

2011-01-01

149

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

150

Mobile systems; From chaos to convergence  

NASA Astrophysics Data System (ADS)

An outline of the two most recent and significant mobile communication developments in Europe is given. These are the Global System for Mobility (GSM) and Digital European Cordless Telecoms (DECT). A summary of advanced communications research is also presented, and the topics covered include the following: Research into Advanced Communications in Europe (RACE); 3rd-generation mobile communication systems; a common unified Universal Mobile Telecommunications Service (UMTS); convergence of mobile radio services; and equipment interface standardization. Finally, a brief review is given of the areas where further antenna and propagation research is needed: handset antennas, in-building propagation, and full system emulation.

Swain, R. S.

151

An old issue and a new look: electromagnetic hypersensitivity caused by radiations emitted by GSM mobile phones.  

PubMed

University students use mobile phones frequently. We previously showed that there was no association between mobile phone use and EMF health hazards among university students. As our previous study was based only on self-reported symptoms this double-blind study was designed to answer two basic questions. Firstly, are self-reported hypersensitive individuals capable of sensing whether there is a real/sham microwave exposure? Secondly, do hypersensitive patients show alterations in their biological parameters such as heart rate, respiration, and blood pressure during microwave exposure? The study consisted of a preliminary screening phase and two subsequent complementary phases. In the 1st phase, 700 students were screened for EMF hypersensitivity. Fifty two participants were hypersensitive individuals but after applying the exclusion criteria only 28 students were invited to take part in the 2nd and 3rd phase of the study, but only 20 students (71.4%) declared their informed consent. In the 2nd phase, these self reported hypersensitive participants, were exposed/sham exposed to microwave radiation emitted from a mobile phone for 10 minutes and they were asked if they could sense the existence of microwave radiation. In the 3rd phase, all students were connected to ICU monitoring devices and their basic physiological parameters were recorded precisely. Among self-reported symptoms reported in our previous study, in this study only problem in concentration (P < 0.05) and low back pain (P < 0.05) were associated with mobile phone use. Furthermore, there was a significant association between the location of mobile phone during talk and the overall score of the severity of the symptoms (P < 0.001). When the participants were asked to report their perception about the real and sham exposures, only 5 students (25%) could discriminate the real exposure/sham exposure phases. This relative frequency can be only due to chance. In the 3rd phase all of the 20 participants were connected to intensive care unit monitors and the changes in their heart rate, respiration, and blood pressure during real/sham exposure were recorded. No statistically significant changes between the means of these parameters in real/sham exposure were observed. Our findings clearly confirm the results obtained inother provocative studies. These data also indicate the possible role of psychological factors in electromagnetic hypersensitivity. PMID:22129944

Mortazavi, S M J; Mahbudi, A; Atefi, M; Bagheri, Sh; Bahaedini, N; Besharati, A

2011-01-01

152

Evaluation of Mobile Communications: From Voice Calls to Ubiquitous Multimedia Group Communications  

E-print Network

IV1/1 Evaluation of Mobile Communications: From Voice Calls to Ubiquitous Multimedia Group@docomolab-euro.com Abstract Today, mobile communications play a central role in the voice/data network arena address the evolution of mobile communications, from its first generation, 1G, to the latest 3G, and give

Monteiro, Edmundo

153

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

154

Hybrid Mobile Communication Networks for Planetary Exploration  

NASA Technical Reports Server (NTRS)

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

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

2007-01-01

155

Multi-agent system security for mobile communication  

E-print Network

Multi-agent system security for mobile communication Niklas Borselius Technical Report RHUL­MA­2003;Abstract This thesis investigates security in multi-agent systems for mobile communica- tion. Mobile as well as non-mobile agent technology is addressed. A general security analysis based on properties

Dent, Alexander W.

156

Communication base contenus dans les rseaux mobiles ad hoc discontinus  

E-print Network

Communication « basée contenus » dans les réseaux mobiles ad hoc discontinus Frédéric Guidec environment. MOTS-CL?S : communication, réseau, mobile, ad hoc, basée contenus, opportuniste, tolérant les délais KEYWORDS: communication, networking, mobile, ad hoc, content-based, opportunistic, delay- tolerant

Paris-Sud XI, Université de

157

FH-GSM frequency hopping GSM  

Microsoft Academic Search

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

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

1994-01-01

158

Frequency addressable beams for land mobile communications  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

159

Learning significant user locations with GPS and GSM  

E-print Network

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

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

2006-01-01

160

Structure and tie strengths in mobile communication networks  

Microsoft Academic Search

Electronic databases, from phone to emails logs, currently provide detailed records of human communication patterns, offering novel avenues to map and explore the structure of social and communication networks. Here we examine the communication patterns of millions of mobile phone users, allowing us to simultaneously study the local and the global structure of a society-wide communication network. We observe a

J.-P. Onnela; J. Saramaki; J. Hyvonen; G. Szabo; D. Lazer; K. Kaski; J. Kertesz; A.-L. Barabasi

2007-01-01

161

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

162

An integrated mobile satellite broadcast, paging, communications and navigation system  

NASA Astrophysics Data System (ADS)

The present integrated mobile satellite broadcast, paging, communications and navigation system will use Ku-band and Radiosat ground stations to broadcast digital audio signals and data packets to mobile receivers via a satellite scheduled for launch in 1993. Each mobile radio simultaneously receives L-band digital audio and data broadcasts from GPS through a common omnidirectional mobile antenna and receiver front end. Radiosat mobile radios will employ the GPS broadcasts and differential corrections through the satellite with 2-m accuracy.

Noreen, Gary K.

1990-12-01

163

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; Daz-Guilera, Albert

2012-01-01

164

Development of Mobile Communications in Slovenia: Looking to the Future Global Information (Mobile/Internet) Society.  

ERIC Educational Resources Information Center

Discusses the planning and provision of mobile communications in Slovenia and suggests areas that will be developed in the future. Topics include the global mobile market; digital mobile networks; evolution from voice to multimedia services; wireless application protocol; the Internet; general packet radio service; and universal mobile

Simonic, Tomaz; Mlinar, Tomi

2000-01-01

165

MobileMiner: a real world case study of data mining in mobile communication  

Microsoft Academic Search

ABSTRACT Mobile communication,data analysis has been often used as a background application to motivate many,data mining problems. However, very few data mining researchers have a chance to see a working data mining system on real mo- bile communication data. In this demo, we showcase our new system MobileMiner on a real mobile communication data set, which presents a case study

Tengjiao Wang; Bishan Yang; Jun Gao; Dongqing Yang; Shiwei Tang; Haoyu Wu; Kedong Liu; Jian Pei

2009-01-01

166

Human-Centered Approach Evaluating Mobile Sign Language Video Communication  

E-print Network

they communicate in sign language. American Sign Language (ASL) is signed in the United States (U research contributes to the MobileASL (American Sign Language) project [9] by applying electricalHuman-Centered Approach Evaluating Mobile Sign Language Video Communication Jessica J. Tran1 , Eve

Wobbrock, Jacob O.

167

Department of Mobile Communications 2229, route des Crtes  

E-print Network

EURECOM1 Department of Mobile Communications 2229, route des Crêtes B.P. 193 06904 Sophia-Antipolis FRANCE Research report RR-11-252 IP Mobile Multicast: Problems and Solutions March 15th , 2011 Thesis-to-many communication over an IP infrastructure in a network. It provides an efficient and cost effective way

Gesbert, David

168

The mobile radio extension of the SOTRIN Area Communication System  

Microsoft Academic Search

The concept of the SOTRIN SCRA (single-channel radio access), the mobile radio extension of the SOTRIN Area Communication System that is fully compliant with EUROCOM specifications, is described. IT provides full duplex VHF radio communications to mobile users, with TRANSEC and COMSEC protection, offering the same numbering scheme and services as for the static subscribers. The SCRA can also work

Angelo BRIGANTE; Giovanni GUIDOTTI

1992-01-01

169

Efficient QoS Provisioning for Adaptive Multimedia in Mobile Communication Networks by Reinforcement Learning  

E-print Network

Efficient QoS Provisioning for Adaptive Multimedia in Mobile Communication Networks networks have motivated the development of adaptive multimedia services in mobile communication networks of the proposed scheme in adaptive multimedia mobile communication networks. 1. Introduction Recent years have

Wong, Vincent

170

76 FR 63657 - Certain Devices for Mobile Data Communication; Notice of Institution of Investigation...  

Federal Register 2010, 2011, 2012, 2013, 2014

...337-TA-809] Certain Devices for Mobile Data Communication; Notice of Institution...of certain devices for mobile data communication by reason of infringement...of certain devices for mobile data communication that infringe one or...

2011-10-13

171

Mobility, Access Heterogeneity and Security for Next Generation Public Safety Communications  

E-print Network

Mobility, Access Heterogeneity and Security for Next Generation Public Safety Communications Giuliana Iapichino, Christian Bonnet Mobile Communications Department Eurecom Sophia Antipolis, France name communications and a complete description of the PMIPv6-HIP mobility management phases is provided. Keywords

Gesbert, David

172

75 FR 3914 - Recordation of Trade Name Sony Ericsson Mobile Communications AB  

Federal Register 2010, 2011, 2012, 2013, 2014

...Trade Name ``Sony Ericsson Mobile Communications AB'' AGENCY: Customs and...notice that ``Sony Ericsson Mobile Communications AB'' has been recorded...trade name by Sony Ericsson Mobile Communications AB. The application...

2010-01-25

173

78 FR 38361 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Communications Devices, Including Mobile Phones and Components Thereof; Institution...communications devices, including mobile phones and components thereof, by reason...communications devices, including mobile phones and components thereof, by...

2013-06-26

174

Chronic exposure to a GSM-like signal (mobile phone) does not stimulate the development of DMBA-induced mammary tumors in rats: results of three consecutive studies.  

PubMed

Certain epidemiological and experimental studies raised concerns about the safety of radiofrequency (RF) electromagnetic fields because of a possible increased risk of leukemia and lymphoma. In this study, an RF field used in mobile telecommunication was tested using 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors in female Sprague-Dawley rats as a model for human breast cancer. Three experiments were carried out under strictly standardized conditions and were started on the same day of three consecutive years. The field consisted of a GSM-like signal (900 MHz pulsed at 217 Hz, pulse width 577 micros) of relatively low power flux density (100 microW/cm(2) +/- 3 dB) and was applied continuously throughout each experiment to freely moving animals. The specific absorption rates averaged over the whole body were 17.5-70 mW/kg. The highest values in young animals were at or around the exposure limit permissible for the general public (i.e. 80 mW/kg). The animals were palpated weekly for the presence of mammary tumors and were killed humanely when tumors reached a diameter of 1-2 cm to allow a reliable histopathological classification and a distinction between malignant and benign subtypes. The overall results of the three studies are that there was no statistically significant effect of RF-field exposure on tumor latency and that the cumulative tumor incidence at the end of the experiment was unaffected as well. The risk ratios were 1.08 (95% CI: 0.91-1.29) and 0.96 (95% CI: 0.85-1.07) for benign and malignant tumors, respectively. These observations are in agreement with other published findings. In the first experiment, however, the median latency for the development of the first malignant tumor in each animal was statistically significantly extended for RF-field-exposed animals compared to controls (278 days compared to 145 days, P = 0.009). No such differences were detected in the two subsequent experiments. These results show that low-level RF radiation does not appear to possess carcinogenic or cancer-promoting effects on DMBA-induced mammary tumors. To explain the mechanisms underlying the different results obtained in the three experiments, a hypothesis is presented which is based upon the neuroendocrine control mechanisms involved in the promotion of DMBA-induced mammary tumors. Despite the apparent absence of stimulatory effects of low-level RF-field exposure on the development and growth of solid tumors, it will be necessary to verify these results for leukemias and lymphomas, which may have completely different biological control mechanisms. PMID:11835682

Bartsch, H; Bartsch, C; Seebald, E; Deerberg, F; Dietz, K; Vollrath, L; Mecke, D

2002-02-01

175

Key Establishment Protocols for Secure Mobile Communications: A Selective Survey  

Microsoft Academic Search

. We analyse several well-known key establishment protocolsfor mobile communications. The protocols are examined with respectto their security and suitability in mobile environments. In a numberof cases weaknesses are pointed out, and in many cases refinements aresuggested, either to improve the efficiency or to allow simplified securityanalysis.1 IntroductionSecurity is a critical issue in mobile radio applications, both for the users

Colin Boyd; Anish Mathuria

1998-01-01

176

Applying mobile IP over wireless ATM communication networks  

Microsoft Academic Search

Advances in mobile devices' and networks' technology have set a challenging pace for all new proposals in the rapidly growing domain of mobile communications. The decade of the 90's brought a revolution in mobile computing. The explosion in sales of laptop PCs as well as personal digital assistants and cellular phones has marked the beginning of a new era in

J. Soldatos; D. D. Vergados; N. Protopsaltis; C. Lykou; G. Kormentzas; C. Anagnostopoulos; M. Theologou

2001-01-01

177

RadioActive: Enabling Persistent Mobile Communications for Groups  

E-print Network

1 RadioActive: Enabling Persistent Mobile Communications for Groups Abstract Current mobile takes the first step in this direction by creating and evaluating an initial design called RadioActive. RadioActive is a technological and interaction design for persistent mobile audio chat spaces. Our work

178

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

179

78 FR 34132 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...  

Federal Register 2010, 2011, 2012, 2013, 2014

...No 2958] Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Correction...entitled Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof, DN...

2013-06-06

180

An Adaptive Communication Protocol for Cooperating Mobile Robots  

Microsoft Academic Search

We describe mobile robots engaged in a cooperative task that requires communication. The robots are initially given a fixed but uninterpreted vocabulary for communication. In attempting to perform their task, the robots learn a private communication language. Different meanings for vocabulary elements are learned in different runs of the experiment. As circumstances change, the robots adapt their language to allow

Holly Yanco; Lynn Andrea Stein

1993-01-01

181

A generalized transmultiplexer and its application to mobile satellite communications  

NASA Technical Reports Server (NTRS)

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

Ichiyoshi, Osamu

1990-01-01

182

FD/DAMA Scheme For Mobile/Satellite Communications  

NASA Technical Reports Server (NTRS)

Integrated-Adaptive Mobile Access Protocol (I-AMAP) proposed to allocate communication channels to subscribers in first-generation MSAT-X mobile/satellite communication network. Based on concept of frequency-division/demand-assigned multiple access (FD/DAMA) where partition of available spectrum adapted to subscribers' demands for service. Requests processed, and competing requests resolved according to channel-access protocol, or free-access tree algorithm described in "Connection Protocol for Mobile/Satellite Communications" (NPO-17735). Assigned spectrum utilized efficiently.

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

1992-01-01

183

How does the user interface design of mobile devices influence the social impact of mobile communication?  

Microsoft Academic Search

1. Abstract This paper describes how user interface design of mobile devices interacts with the social impact of mobile communication. Social impact is defined as the influence on relationships between social actors. In the light of mobile communication, one can distinguish among at least three relevant classes of relationships: human-machine relationships, interpersonal relationships between co-located persons, and machine mediated human-human

Stefan Marti

2002-01-01

184

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

185

Mobile communications via satellite in the 1990s  

NASA Astrophysics Data System (ADS)

The International Maritime Satellite Organization (Inmarsat) began operations in February 1982. It has the objective to provide satellite communications capacity which can best serve the mobile user in the international environment. It is pointed out that Inmarsat is the world's only organization providing commercial mobile communications via satellite. Inmarsat is concerned with the improvement of maritime communications. Attention is given to structure and financing, the Inmarsat satellites in geostationary orbit, the coast earth stations, the ship earth stations, applications and users, a future global maritime distress and safety system, polar-orbiting satellites, aeronautical communications, and the second-generation system.

Lundberg, O.

1984-07-01

186

Communication Concepts for Mobile Agent Systems  

Microsoft Academic Search

Driven by the question how to identify potential communication partners and the need for well-suited communication schemes in agent-based systems, we discuss two communication concepts: sessions and global event management.

Joachim Baumann; Fritz Hohl; Nikolaos Radouniklis; Kurt Rothermel; Markus Straer

1997-01-01

187

WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. (2012)  

E-print Network

data diffusion for wireless mobile networks Mohammad Towhidul Islam1 , Mursalin Akon1 , Atef Abdrabou2 to uproot a terror network, communicating in a hostile battle field), and in natural catastrophe (seamless

Shen, Xuemin "Sherman"

2012-01-01

188

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

189

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

190

Reconfigurable Multiband Antenna Designs for Wireless Communication Devices  

Microsoft Academic Search

New designs for compact reconfigurable antennas are introduced for mobile communication devices. The uniqueness of the antenna designs are that they allow various groups of their operating frequency bands to be selected electronically. In particular, each group of frequency bands, or mode, can be made to serve several different communication systems simultaneously. These systems may include various combinations of GSM,

Angus C. K. Mak; Corbett R. Rowell; Ross D. Murch; Chi-Lun Mak

2007-01-01

191

Inferring human mobility using communication patterns  

E-print Network

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. 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 da...

Palchykov, Vasyl; Jo, Hang-Hyun; Saramki, Jari; Pan, Raj Kumar

2014-01-01

192

A survey of various propagation models for mobile communication  

Microsoft Academic Search

In order to estimate the signal parameters accurately for mobile systems, it is necessary to estimate a system's propagation characteristics through a medium. Propagation analysis provides a good initial estimate of the signal characteristics. The ability to accurately predict radio-propagation behavior for wireless personal communication systems, such as cellular mobile radio, is becoming crucial to system design. Since site measurements

Tapan K. Sarkar; Zhong Ji; Kyungiung Kim; A. Medouri; Magdalena Salazar-Palma

2003-01-01

193

Performance of CDMA mobile communication systems using antenna arrays  

Microsoft Academic Search

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

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

1993-01-01

194

Effect of MobileASL on Communication Among Deaf Users  

E-print Network

Effect of MobileASL on Communication Among Deaf Users Abstract MobileASL, a software program, field study, American Sign Language, Deaf community. ACM Classification Keywords H.5.1. [Information (Figure 2) or by holding the device in one hand and signing with the other. Currently, members of the Deaf

Wobbrock, Jacob O.

195

Fully mobile functional brain spectroscopy using near-infrared light and wireless networks  

Microsoft Academic Search

This thesis presents research that creates a mobile solution to monitor human brain functions during real-life activities. The solution utilizes the Internet, the Global Standard for Mobile Communication (GSM) wireless networks, Bluetooth technology, and a number of data protocols. It consists of three main parts: 1. a Bluetooth portable near-infratred light sensor, 2. a personal digital assistant (PDA), and 3.

Salah Sharieh

2008-01-01

196

Siting of GSM Base Station Antenna and Its Health Consequences  

Microsoft Academic Search

In Nigeria 98% of Global System for Mobile (GSM) base stations (cell sites) are sited within 20 meters from residential, offices, schools, business buildings, petrol stations and public arenas. 97.1% of these mobile base station antennas have their far field zone, which ranges between 110 m to 270 m, and are centred on densely populated areas. Cell phone antennas emit

R. E. Okonigene

2010-01-01

197

WILEY WIRELESS COMMUNICATIONS AND MOBILE COMPUTING 1 Cognitive Engine Implementation for Wireless  

E-print Network

WILEY WIRELESS COMMUNICATIONS AND MOBILE COMPUTING 1 Cognitive Engine Implementation for Wireless, 2006 DRAFT #12;WILEY WIRELESS COMMUNICATIONS AND MOBILE COMPUTING 2 I. INTRODUCTION Cognitive radio is the primary feature of cognitive radios for wireless communication systems. Genetic algorithms (GA

Kansas, University of

198

Application-driven power management for mobile communication  

Microsoft Academic Search

In mobile computing, power is a limited resource. Like other devices, communication devices need to be properly managed to conserve energy. In this paper, we present the design and implementation of an innovative transport level protocol capable of significantly reducing the power usage of the communication device. The protocol achieves power savings by selectively choosing short periods of time to

Robin Kravets; P. Krishnan

2000-01-01

199

Current Approaches to Authentication in Wireless and Mobile Communications Networks  

Microsoft Academic Search

This document1gives a brief introduction into algorithms and protocols for entity authentication(verifying the identity of communication partners) and analyzes the approaches for realizing authenticationin current mobile communication standards. The main results of this comparative analysisconcerning an authentication infrastructure for wireless Internet access are, that (1) the protocols asproposed in current IETF working groups still need further evaluation of their security...

G. Schfer; A. Festag; H. Karl

2001-01-01

200

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

201

A scalable group communication mechanism for mobile agents  

Microsoft Academic Search

Many multi-agent applications based on mobile agents require message propagation among group of agents. A fast and scalable group communication mechanism can considerably improve performance of these applications. Unfortunately, most of the existing approaches do not scale well and disseminate messages slowly when the number of agents grows.In this paper, we propose Sama, a new group communication mechanism, to speed

Hojjat Jafarpour; Nasser Yazdani; Navid Bazzaz-zadeh

2007-01-01

202

WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. (2013)  

E-print Network

WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. (2013) Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/wcm.2450 RESEARCH ARTICLE Multi Army Communications-Electronics RD&E Center, 6003 Combat Drive, Aberdeen Proving Grouond, MD 21005

Ansari, Nirwan

203

An improved procedure to accurately assess the variability of the exposure to electromagnetic radiation emitted by GSM base station antennas  

NASA Astrophysics Data System (ADS)

Long-term human exposure around Global System for Mobile Communications (GSM) base station antennas has not yet been precisely established; this is of interest from human health and epidemiological perspectives. Actual exposure is difficult to assess accurately, mainly because there is a lack of technical information directly from the GSM operators. The in situ measurement standards available at present provide only a worst-case prediction method; the present work goes beyond this and proposes a methodology that, without the need for data from operators, allows a reliable way to express real exposure with a greater accuracy than all other methods proposed to date. The method is based on dual measurements of the signal strengths in the frequency domain and the time domain and takes into consideration the instantaneous traffic in GSM channels. In addition, it allows a channel-individualized exposure assessement, by making possible the separate analysis of the electric field level in the two types of channel of the GSM standardthe traffic channels and the control channels.

Bechet, Paul; Miclaus, Simona

2013-01-01

204

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

205

Signalling characteristics in satellite-aided land mobile communications  

NASA Technical Reports Server (NTRS)

The feasibility of land mobile radio communications has been demonstrated by a large number of experiments with NASA's ATS satellites. Significant differences in the propagation characteristics of satellite and terrestrial mobile signal paths were observed in the experiments. Terrestrial paths are best in cities where they can provide frequency reuse and assure communication by bouncing signals around obstructions. Satellites may be best in thinly populated areas because they eliminate the need for many tower mounted relays. The satellite paths do not have the severe Rayleigh fading that limits the range and signal quality of terrestrial paths if the satellite is above approximately ten degrees elevation, a value easily achieved for the United States. The experiments verified that high quality voice communications and other functions, such as data transmission and vehicle position surveillance, are easily accomplished through geostationary satellites with vehicle transmitter power and antenna gain no different than those of terrestrial mobile communications.

Anderson, R. E.

1982-01-01

206

CURRENT DEGREE PROGRAMS GSM NON-DEGREE  

E-print Network

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

Guenther, Frank

207

Tracking Mobile Users in Wireless Communication Networks  

Microsoft Academic Search

Tracking strategies for mobile wireless networks are studied. We assume a cellulararchitecture where base stations that are interconnected by a wired network communicatewith mobile units via wireless links. Previous works focused on the cost of utilizing thewired links for management of directories. In this paper, the issue considered is thecost of utilizing the wireless links for the actual tracking of

Amotz Bar-noy; Ilan Kessler

1993-01-01

208

Intelligent network concepts in mobile communications  

Microsoft Academic Search

A mobile cellular network architecture that is based on intelligent network concepts is presented. Subscriber service mobility and call management attributes of the network, including location information retrieval and updating, authentication, call routing, handover, charging, and operations and maintenance, are discussed

Bijan Jabbari

1992-01-01

209

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; Saramki, Jari; Pan, Raj Kumar

2014-08-01

210

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; Saramki, Jari; Pan, Raj Kumar

2014-01-01

211

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; Saramki, Jari; Pan, Raj Kumar

2014-01-01

212

A statistical model of mobile-to-mobile land communication channel  

Microsoft Academic Search

A statistical model applicable to a local area has been developed for mobile-to-mobile urban and suburban land communication channels. Using the model, the probability distributions of the received envelope and phase, spatial-time correlation function, and the power spectral density of the complex envelope have been developed.

ABDULKADER S. AKKI; F. Haber

1986-01-01

213

Activity Analysis Enabling Real-Time Video Communication on Mobile Phones for Deaf Users  

E-print Network

Activity Analysis Enabling Real-Time Video Communication on Mobile Phones for Deaf Users Neva communication on the current U.S. mobile phone network. The goal of MobileASL is to enable Deaf people to com.. Copyright 2009 ACM 978-1-60558-745-5/09/10 ...$10.00. Figure 1: Deaf people can use MobileASL to communicate

Anderson, Richard

214

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

215

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

216

EE 447 Mobile Wireless Communications -Fall 2010 R. Wolff, Fall 2010, EE447 Page 1  

E-print Network

EE 447 Mobile Wireless Communications - Fall 2010 R. Wolff, Fall 2010, EE447 Page 1 Instructor "Mobile Wireless Communications", Mischa Schwartz "Contemporary Communication Systems using Matlab", Jon Proakis #12;EE 447 Mobile Wireless Communications - Fall 2010 R. Wolff, Fall 2010, EE447 Page 2 Grading

Wolff, Richard

217

EMERGING PATTERNS OF AMERICAN MOBILE PHONE USE: Electronically-mediated communication in transition  

E-print Network

EMERGING PATTERNS OF AMERICAN MOBILE PHONE USE: Electronically-mediated communication in transition about mobile telephony as an American form of electronically-mediated communication. To address-mediated communication, electronically-mediated communication, mobile phones, SMS, texting Author Biographies Naomi S

Carlini, David

218

A group communication approach for mobile computing  

Microsoft Academic Search

Describes the design and implementation of a set of tools, called MobileChannel, for use with the Isis system. A simple scheme to support user mobility-switching a control point between replicated servers-provides a uniform mechanism to handle both client migrations and server failures. The hands-off mechanism is simplified by integrating a FIFO channel implementation into the server replication mechanism. Our scheme

K. Cho; K. P. Birmans

1994-01-01

219

Linear amplification technique for digital mobile communications  

Microsoft Academic Search

The author proposes a novel predistortion linearizer which can meet the power-amplification requirements of digital mobile radio systems with high power efficiency and low out-of-band emission. This method can be used for narrowband mobile radio systems. It has been shown that the linearizer can achieve low-out-of-band emission under frequent changes of the amplifier nonlinearity. It is indicated that the hardware

Yoshinori Nagata

1989-01-01

220

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

221

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

222

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

223

A survey on electromagnetic interferences on aircraft avionics systems and a GSM on board system overview  

NASA Astrophysics Data System (ADS)

Recent years have been characterized by an increase in the air traffic. More attention over micro-economic and macroeconomic indexes would be strategic to gather and enhance the safety of a flight and customer needing, for communicating by wireless handhelds on-board aircrafts. Thus, European Telecommunications Standards Institute (ETSI) proposed a GSM On Board (GSMOBA) system as a possible solution, allowing mobile terminals to communicate through GSM system on aircraft, avoiding electromagnetic interferences with radio components aboard. The main issues are directly related with interferences that could spring-out when mobile terminals attempt to connect to ground BTS, from the airplane. This kind of system is able to resolve the problem in terms of conformance of Effective Isotropic Radiated Power (EIRP) limits, defined outside the aircraft, by using an On board BTS (OBTS) and modeling the relevant key RF parameters on the air. The main purpose of this work is to illustrate the state-of-the-art of literature and previous studies about the problem, giving also a good detail of technical and normative references.

Vinto, Natale; Tropea, Mauro; Fazio, Peppino; Voznak, Miroslav

2014-05-01

224

Department of Mobile Communications Campus Sophia Tech  

E-print Network

/IP stack can be very problematic and DTN architecture aims to overcome the communication obstacles. DTN architecture and its transport layer techniques have been more recently considered suitable . . . . . . . . . . 4 4 Transport layer Mechanisms 5 4.1 DTN Architecture

Gesbert, David

225

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

226

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

227

Optimization of wireless resources for personal communications mobility tracking  

Microsoft Academic Search

ABSTRACT In personal communications applications, users communicate via wireless with a wireline network. The wireline network tracks the current location of the user, and can therefore route messages to a user regardless of the users location. In addition to its impact on signaling within the wireline network, mobility tracking requires the expenditure of wireless resources as well, including the power,consumption,of

Upamanyu Madhow; Michael L. Honig; Kenneth Steiglitz

1995-01-01

228

Mobile satellite communications - Applications for developing countries  

NASA Astrophysics Data System (ADS)

The paper considers the institutional commitments and development of new service applications of the International Maritime Satellite Organization. It illustrates how a mobile-satellite system can offer a range of applications and reach user communities that cannot be served by fixed systems.

von Noorden, Wolf D.

229

76 FR 80402 - Certain Personal Data and Mobile Communications Devices and Related Software; Final Determination...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Mobile Communications Devices and Related Software; Final Determination Finding Violation...mobile communications devices and related software. The Commission has determined that...Apple Inc., and its subsidiary NeXT Software, Inc., both of Cupertino,...

2011-12-23

230

77 FR 40083 - Certain Personal Data and Mobile Communications Devices and Related Software; Institution of a...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Mobile Communications Devices and Related Software; Institution of a Formal Enforcement...Apple Inc., and its subsidiary NeXT Software, Inc., both of Cupertino, California...mobile communications devices and related software. 75 FR 17434 (Apr. 6, 2010)....

2012-07-06

231

77 FR 60721 - Certain Devices for Mobile Data Communication; Notice of Commission Determination Not To Review...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Investigation No. 337-TA-809] Certain Devices for Mobile Data Communication; Notice of Commission Determination Not To...States after importation of certain devices for mobile data communication by reason of infringement of various...

2012-10-04

232

77 FR 69501 - Certain Devices for Mobile Data Communication; Determination Not To Review an Initial...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Investigation No. 337-TA-809] Certain Devices for Mobile Data Communication; Determination Not To Review an Initial Determination...States after importation of certain devices for mobile data communication by reason of infringement of certain...

2012-11-19

233

Mobile Communication Device Procedures The following procedure, effective June 1, 2011, sets forth the rules for business use of Mobile  

E-print Network

5/16/2011 Mobile Communication Device Procedures Overview The following procedure, effective June 1, 2011, sets forth the rules for business use of Mobile Communication Devices (MCD) by permanent and cost effective means of communication should be considered before authorizing employees

234

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

235

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

236

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

237

Mobile Visual Communication Photo Messages and Camera Phone Photography  

Microsoft Academic Search

In this article I will elucidate the concept of photo messaging, and examine camera phones in the context of communication and photography. Camera functions are nowadays a popular add-on to the mobile (cellular) phone. Users can send photographs directly from the phone as photo messages. Findings suggest that the ubiquitous camera phone, and photo messaging, may substantially change the ways

MIKKO VILLI

238

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

239

A study of adaptive arrays for mobile communication systems  

Microsoft Academic Search

The application of adaptive antenna techniques to increase the channel capacity in mobile radio communication is discussed. Directional sensitivity is obtained by using an antenna array at the base station, possibly both in receiving and transmitting mode. A scheme for separating several signals at the same frequency is proposed. The method is based on high-resolution direction finding following by optimal

S. Andersson; M. Millnert; M. Viberg; B. Wahlberg

1991-01-01

240

Performance of an OFDM-TDMA mobile communication system  

Microsoft Academic Search

The multicarrier transmission technique (OFDM) is considered in combination with a TDMA\\/TDD multiple access scheme for a cellular mobile communication system. Performance analysis is presented for the uncoded and coded (TCM) case. It is shown that OFDM systems have a large potential concerning the flexible allocation of the total given bandwidth to different users. This flexibility can be exploited to

H. Rohling; R. Griinheid

1996-01-01

241

A Model and Measure of Mobile Communication Competence  

ERIC Educational Resources Information Center

This article deals with two studies that develop a measure and model of mobile communication competence (MCC). The first study examines the dimensionality of the measure by conducting an exploratory factor analysis on 350 students at a large university in the midwestern United States. Results identified six constructs across 24 items: willingness

Bakke, Emil

2010-01-01

242

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

243

Radiowave propagation in mobile communications: an overview of European research  

Microsoft Academic Search

Detailed knowledge of radio propagation effects is a keystone for the development and performance assessment of mobile communication systems. Although a lot of investigations have already been carried out, there remains a need to gain deeper insight into the complex mechanisms which govern radio propagation. The authors first present a summary of the propagation mechanisms and discuss some issues related

B. H. Fleury; P. E. Leuthold

1996-01-01

244

The Role of Mobile Phones in Family Communication  

ERIC Educational Resources Information Center

Whilst there is a wealth of research into family communication and family relationships, there is little information about whether (and if so how) mobile phones have impacted on these processes. The authors' study involved individual semi-structured interviews with 60 families, including parents/carers and young people aged 11-17, to investigate

Devitt, Kerry; Roker, Debi

2009-01-01

245

Performance of CDMA\\/OFDM for mobile communication system  

Microsoft Academic Search

The OFDM technique is an interesting approach in mobile communications in order to achieve a high spectral efficiency and to combat the frequency selectivity of the channel. Another interesting technique is a CDMA system with Rake-receiver. The main advantages of CDMA are well known, but its capacity is limited by multiuser interference. The aim of this study is to combine

K. Fazel

1993-01-01

246

A Facial Sketch Animation Generator for Mobile Communication  

Microsoft Academic Search

The ability to analyze and reproduce specific-person facial expression is an important multimedia content service for mobile communication. In this paper, a novel three-layer facial animation model is presented for generating the personalized facial sketch animation, and the three layers are motion sequence layer, the reference shape layer, and the painting shape layer. Based on the model, a facial sketch

Yuehu Liu; Yuanqi Su; Yang Yang; Fengjuan Wang; Maojun Yuan; Zhen Ren

2007-01-01

247

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. Gckler

1995-01-01

248

Global Mobility Management by Replicated Databases in Personal Communication Networks*  

E-print Network

- 1 - Global Mobility Management by Replicated Databases in Personal Communication Networks* Kin K for the management of PCN is to develop an efficient database architecture so that customer data can be readily}@att.com October 1, 1996 April 18, 1997 (revised) ABSTRACT This paper explores the use of replicated databases

Leung, Kin K.

249

An Architecture for Security and Privacy in Mobile Communications  

Microsoft Academic Search

There is much discussion and debate about how to improve the security and privacy of mobile communication systems, both voice and data. Most proposals attempt to provide incremental improvements to systems that are deployed today. Indeed, only incremental improvements are possible, given the regulatory, techno- logical, economic, and historical structure of the telecommunications system. The terrorist attacks of September 11,

G. Winfield Treese; Lawrence C. Stewart

2001-01-01

250

WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. (2011)  

E-print Network

WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. (2011) Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/wcm.1093 RESEARCH ARTICLE Sequential 1, FFR divides the whole frequency bandwidth into two reserved parts: cell-edge bandwidth, and cell-center

Lee, Tae-Jin

251

Safety Monitoring System by Autonomous Mobile Sensors Utilizing Pheromone Communication  

Microsoft Academic Search

Highly reliable safety monitoring systems are indispensable for operating large-scale systems, such as nuclear power plants. This paper proposes anew type of reliable safety monitoring system employing a small number of autonomous decentralized mobile sensors. The new system is called ant-like sensor system (ALSS), and consists of autonomous sensors utilizing pheromone communication. Each sensor moves around, leaving the markings of

Kenji Tanaka; Yo Ishigaki; Hiroyulu Inoue; Makoto Itoh

2005-01-01

252

Daily rhythms in mobile telephone communication  

E-print Network

Circadian rhythms are known to be important drivers of human activity and the recent availability of electronic records of human behaviour has provided fine-grained data of temporal patterns of activity on a large scale. Further, questionnaire studies have identified important individual differences in circadian rhythms, with people broadly categorised into morning-like or evening-like individuals. However, little is known about the social aspects of these circadian rhythms, or how they vary across individuals. In this study we use a unique 18-month dataset that combines mobile phone calls and questionnaire data to examine individual differences in the daily rhythms of mobile phone activity. We demonstrate clear individual differences in daily patterns of phone calls, and show that these individual differences are persistent despite a high degree of turnover in the individuals' social networks. Further, women's calls were longer than men's calls, especially during the evening and at night, and these calls wer...

Aledavood, Talayeh; Roberts, Sam G B; Reed-Tsochas, Felix; Moro, Esteban; Dunbar, Robin I M; Saramki, Jari

2015-01-01

253

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

254

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

255

Mobility of a Disaster Recover Communication System  

Microsoft Academic Search

What is the best platform to build a Disaster Management Communication System (DMCS)? There is a need to investigate how to best use a DMCS. The two most important uses of a DMCS for any size disaster, is the need for information and getting relief to those that need it. The DMCS needs to collect information from the people affected

Edward Sobanski; Barbara Nicolai

2011-01-01

256

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

257

George Spanogiannopoulos CSE 5431 Mobile Communications  

E-print Network

Field Coupling Long range communication ElectroMagnetic Wave Capture powers tag Backscatter used is RFID? Benefits of RFID Technology A Brief History Technical Information RFID System Types/2/2008 George Spanogiannopoulos 11 #12;4/2/2008 George Spanogiannopoulos 12 #12; EM waves propagating from

Vlajic, Natalija

258

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

259

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

260

A communication infrastructure to ease the development of mobile collaborative applications  

Microsoft Academic Search

\\u000aMobile workers doing loosely coupled activities typically perform on demand collaboration in the physical workplace. Communication services available in such work scenarios are uncertain, therefore mobile collaborative applications supporting those activities must provide ad hoc communication mechanisms in order to use each cooperation opportunity. Typically, the complexity of implementing such mobile ad hoc communication mechanisms becomes a challenge that jeopardizes

Juan Rodriguez-Covili; Sergio F. Ochoa; Jos A. Pino; Roc Messeguer; Esunly Medina; Dolors Royo

2010-01-01

261

A communication infrastructure to ease the development of mobile collaborative applications  

Microsoft Academic Search

Mobile workers doing loosely coupled activities typically perform on demand collaboration in the physical workplace. Communication services available in such work scenarios are uncertain, therefore mobile collaborative applications supporting those activities must provide ad hoc communication mechanisms in order to use each cooperation opportunity. Typically, the complexity of implementing such mobile ad hoc communication mechanisms becomes a challenge that jeopardizes

Juan Rodrguez-Covili; Sergio F. Ochoa; Jos A. Pino; Roc Messeguer; Esunly Medina; Dolors Royo

2011-01-01

262

Minimizing Mobility and Communication Energy in Robotic Networks: an Optimal Control Approach  

E-print Network

Minimizing Mobility and Communication Energy in Robotic Networks: an Optimal Control Approach H of motion energy and communication energy in a network of mobile robots. The robotic network is charged to use mobility to reduce the energy required for sensing and communications; see [13] and references

Egerstedt, Magnus

263

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

E-print Network

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 study the efficient use of mobile robots to create a communication bridge between a source

Minnesota, University of

264

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 present a system solution, BeamSwitch, for directional communication on mobile de- vices. Beam been devoted to directional communication, few have studied it for mobile devices, which can not only

Zhong, Lin

265

A new communication paradigm for mobile TV over cellular network Dr. Hongxiang Li  

E-print Network

A new communication paradigm for mobile TV over cellular network Dr. Hongxiang Li Electrical terrestrial TV network and propose a new mobile TV communication paradigm that is radically different from and communication theory (i.e., Network Coding and Dirty Paper Coding) in the new mobile TV system design. Despite

266

The Accuracy of RSS Based Positioning in GSM Networks  

Microsoft Academic Search

This paper deals with performance of positioning in GSM networks based on received signal strength (RSS) measurements. Each mobile station (MS) collects RSS measurements of the downlink control channels transmitted by the surrounding base stations. These measurements can be used to obtain the MS location by means of calculating algorithm. We examine the accuracy of adaptive geometric and least square

Peter Brida; Peter Cepel; J. Duha

2006-01-01

267

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/(sHz) 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

268

Circadian pattern and burstiness in mobile phone communication  

NASA Astrophysics Data System (ADS)

The temporal communication patterns of human individuals are known to be inhomogeneous or bursty, which is reflected as heavy tail behavior in the inter-event time distribution. As the cause of such a bursty behavior two main mechanisms have been suggested: (i) inhomogeneities due to the circadian and weekly activity patterns and (ii) inhomogeneities rooted in human task execution behavior. In this paper, we investigate the role of these mechanisms by developing and then applying systematic de-seasoning methods to remove the circadian and weekly patterns from the time series of mobile phone communication events of individuals. We find that the heavy tails in the inter-event time distributions remain robust with respect to this procedure, which clearly indicates that the human task execution-based mechanism is a possible cause of the remaining burstiness in temporal mobile phone communication patterns.

Jo, Hang-Hyun; Karsai, Mrton; Kertsz, Jnos; Kaski, Kimmo

2012-01-01

269

Distributed Communication for Highly Mobile Agents Mohammad Samarah and Philip Chan  

E-print Network

Distributed Communication for Highly Mobile Agents Mohammad Samarah and Philip Chan The division architectures to address communication issues in mobile agent environments. We study the implication of mobility monitoring, agent tracing, and agent debugging for mobile agent environments. The architecture allows

Chan, Philip K.

270

Channel simulation to facilitate mobile-satellite communications research  

NASA Technical Reports Server (NTRS)

The mobile-satellite-service channel simulator, which is a facility for an end-to-end hardware simulation of mobile satellite communications links is discussed. Propagation effects, Doppler, interference, band limiting, satellite nonlinearity, and thermal noise have been incorporated into the simulator. The propagation environment in which the simulator needs to operate and the architecture of the simulator are described. The simulator is composed of: a mobile/fixed transmitter, interference transmitters, a propagation path simulator, a spacecraft, and a fixed/mobile receiver. Data from application experiments conducted with the channel simulator are presented; the noise converison technique to evaluate interference effects, the error floor phenomenon of digital multipath fading links, and the fade margin associated with a noncoherent receiver are examined. Diagrams of the simulator are provided.

Davarian, Faramaz

1987-01-01

271

Payload system tradeoffs for mobile communications satellites  

NASA Technical Reports Server (NTRS)

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

Moody, H. J.

1990-01-01

272

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

273

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.

274

The Globalstar mobile satellite system for worldwide personal communications  

NASA Technical Reports Server (NTRS)

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.

1993-01-01

275

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

276

Why is CDMA the solution for mobile satellite communication  

NASA Technical Reports Server (NTRS)

It is demonstrated that spread spectrum Code Division Multiple Access (CDMA) systems provide an economically superior solution to satellite mobile communications by increasing the system maximum capacity with respect to single channel per carrier Frequency Division Multiple Access (FDMA) systems. Following the comparative analysis of CDMA and FDMA systems, the design of a model that was developed to test the feasibility of the approach and the performance of a spread spectrum system in a mobile environment. Results of extensive computer simulations as well as laboratory and field tests results are presented.

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

1989-01-01

277

Study of terrestrial mobile systems for personal communications  

NASA Astrophysics Data System (ADS)

System configurations for the provision of satellite communication services to land mobiles in Europe are outlined. A network concept based on message store-and-forward switching techniques is proposed. The links work independently and the control function is distributed amongst the nodes. This gives good system flexibility, enhanced by baseband switching on board the satellite. The proposed system is realizable using short term developments of today's technology, but use of the INMARSAT space segment is a very attractive opportunity to set up at low cost a simplified and compatible demonstration system based on the same concept. Signal transmission techniques and mobile terminal technology are reviewed.

Baudu, J.; Morris, S.; Yongacoglu, A.

1984-11-01

278

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

279

Close relationships: A study of mobile communication records  

E-print Network

Mobile phone communication as a digital service generates ever-increasing datasets of human communication actions, which in turn allow us to investigate the structure and evolution of social interactions and their networks. These datasets can be used to study the structuring of such ego-centric networks with respect to the strength of the relationships by assuming monotonic dependence of the communication intensity on the strength of the social tie. Recently we have discovered that there are significant differences between the first and further 'best friends" from the point of view of age and gender preferences. Here we introduce a control parameter, namely the minimum ratio $r_{min}$ between the intensities of communication of the first and second "best friend" and use it to filter the data. We find that when $r_{min}$ is increased the identification of the "best friend" becomes less ambiguous and the earlier observed effects get stronger, thus corroborating them.

Palchykov, Vasyl; Dunbar, Robin I M; Kaski, Kimmo

2012-01-01

280

Structure and tie strengths in mobile communication networks  

PubMed Central

Electronic databases, from phone to e-mails logs, currently provide detailed records of human communication patterns, offering novel avenues to map and explore the structure of social and communication networks. Here we examine the communication patterns of millions of mobile phone users, allowing us to simultaneously study the local and the global structure of a society-wide communication network. We observe a coupling between interaction strengths and the network's local structure, with the counterintuitive 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, resulting in dynamic trapping of information in communities and find that, when it comes to information diffusion, weak and strong ties are both simultaneously ineffective. PMID:17456605

Onnela, J.-P.; Saramki, J.; Hyvnen, J.; Szab, G.; Lazer, D.; Kaski, K.; Kertsz, J.; Barabsi, A.-L.

2007-01-01

281

Close Relationships: A Study of Mobile Communication Records  

NASA Astrophysics Data System (ADS)

Mobile phone communication as digital service generates ever-increasing datasets of human communication actions, which in turn allow us to investigate the structure and evolution of social interactions and their networks. These datasets can be used to study the structuring of such egocentric networks with respect to the strength of the relationships by assuming direct dependence of the communication intensity on the strength of the social tie. Recently we have discovered that there are significant differences between the first and further "best friends" from the point of view of age and gender preferences. Here we introduce a control parameter p max based on the statistics of communication with the first and second "best friend" and use it to filter the data. We find that when p max is decreased the identification of the "best friend" becomes less ambiguous and the earlier observed effects get stronger, thus corroborating them.

Palchykov, Vasyl; Kertsz, Jnos; Dunbar, Robin; Kaski, Kimmo

2013-05-01

282

Fixed and mobile multi-beam communications experiment payload  

NASA Astrophysics Data System (ADS)

A multibeam communications satellite has become possible due to recent advances in launch vehicle technology. The Japanese national project to launch a 2-ton class geostationary satellite, Engineering Test Satellite-VI (ETS-VI), is now in progress. On-board equipment is developed for fixed and mobile multibeam satellite communication systems using Ka, S, and C bands. Key technologies such as large-diameter and high-precision reflectors, a low sidelobe-cluster feeder, a precise antenna-pointing control system, a monolithic IC satellite switch, a monolithic IC transponder, a multiport amplifier and a distributed supervisory and control system are planned to be flight-verified in this project.

Tanaka, Masayoshi; Nakagawa, Kazuo; Ohtomo, Isao; Samejima, Shuichi

283

Fixed and mobile satellite communication systems for ETS-VI  

NASA Astrophysics Data System (ADS)

Recent advances in launch vehicle technology have made multibeam communication satellites realistic. The Japanese national project to launch a 2-ton class geostationary satellite, ETS-VI (Engineering Test Satellite-VI), is in progress. NTT involves the development of on-board equipment for fixed and mobile multibeam satellite communication systems using Ka, S and C bands. Key technologies to be flight-verified are: large-diameter, high-precision reflectors, a low sidelobe cluster feeder, precise antenna pointing control system, monolithic IC satellite switch, monolithic IC transponder, Multi-Port Amplifier, and distributed supervisory and control system.

Nakagawa, Kazuo; Kawai, Makoto; Tanaka, Masayoshi

284

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

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 Seamless Communications for Mobile Emergency ServicesSeamless Communications for Mobile

Abu-Rgheff, Mosa Ali

285

Influence of Mobile Phones on the Quality of ECG Signal Acquired by Medical Devices  

NASA Astrophysics Data System (ADS)

Health aspects of the use of radiating devices, like mobile phones, are still a public concern. Stand-alone electrocardiographic systems and those built-in, more sophisticated, medical devices have become a standard tool used in everyday medical practice. GSM mobile phones might be a potential source of electromagnetic interference (EMI) which may affect reliability of medical appliances. Risk of such event is particularly high in places remote from GSM base stations in which the signal received by GSM mobile phone is weak. In such locations an increase in power of transmitted radio signal is necessary to enhance quality of the communication. In consequence, the risk of interference of electronic devices increases because of the high level of EMI. In the present paper the spatial, temporal, and spectral characteristics of the interference have been examined. The influence of GSM mobile phone on multilead ECG recordings was studied. It was observed that the electrocardiographic system was vulnerable to the interference generated by the GSM mobile phone working with maximum transmit power and in DTX mode when the device was placed in a distance shorter than 7.5 cm from the ECG electrode located on the surface of the chest. Negligible EMI was encountered at any longer distance.

Buczkowski, T.; Janusek, D.; Zavala-Fernandez, H.; Skrok, M.; Kania, M.; Liebert, A.

2013-10-01

286

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

287

FEC decoder design optimization for mobile satellite communications  

NASA Technical Reports Server (NTRS)

A new telecommunications service for location determination via satellite is being proposed for the continental USA and Europe, which provides users with the capability to find the location of, and communicate from, a moving vehicle to a central hub and vice versa. This communications system is expected to operate in an extremely noisy channel in the presence of fading. In order to achieve high levels of data integrity, it is essential to employ forward error correcting (FEC) encoding and decoding techniques in such mobile satellite systems. A constraint length k = 7 FEC decoder has been implemented in a single chip for such systems. The single chip implementation of the maximum likelihood decoder helps to minimize the cost, size, and power consumption, and improves the bit error rate (BER) performance of the mobile earth terminal (MET).

Roy, Ashim; Lewi, Leng

1990-01-01

288

Sama: A Scalable Group Communication Mechanism for Mobile Agents  

E-print Network

Abstract. Provision of fast and scalable group communication for mobile agents can considerably improve their efficiency. Unfortunately, most of the existing approaches do not scale well when the number of agents grows. In this paper, we propose Sama, a new group communication mechanism, to speed up message delivery to a group of mobile agents. The main contribution of Sama is distribution and parallelization of message propagation in an efficient way to achieve scalability and speed up message delivery to the group members. Sama uses Message Dispatcher Objects (MDOs), which are stationary agents on each host, to propagate messages in a parallel manner. The proposed mechanism is independent of agent locations and transparently delivers messages to the group using a constant number of remote messages. Experimental results show that message delivery time is significantly reduced in Sama compared to the previously proposed methods.

Hojjat Jafarpour; Nasser Yazdani; North Kargar St

2003-01-01

289

Trellis-coded CPM for satellite-based mobile communications  

NASA Technical Reports Server (NTRS)

Digital transmission for satellite-based land mobile communications is discussed. To satisfy the power and bandwidth limitations imposed on such systems, a combination of trellis coding and continuous-phase modulated signals are considered. Some schemes based on this idea are presented, and their performance is analyzed by computer simulation. The results obtained show that a scheme based on directional detection and Viterbi decoding appears promising for practical applications.

Abrishamkar, Farrokh; Biglieri, Ezio

1988-01-01

290

Cockpit weather graphics using mobile satellite communications  

NASA Technical Reports Server (NTRS)

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

1993-01-01

291

Paths to consensus in networks of mobile communicating agents  

E-print Network

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 out of 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

2011-01-01

292

First satellite mobile communication trials using BLQS-CDMA  

NASA Technical Reports Server (NTRS)

In this paper, technical results obtained in the first MSBN Land mobile technical trial are reported. MSBN (Mobile Satellite Business Network) is a new program undertaken by the European Space Agency (ESA) to promote mobile satellite communication in Europe, in particular voice capability. The first phase of the MSBN system implementation plan is an experimental phase. Its purpose is to evaluate through field experiments the performance of the MSBN system prior to finalization of its specifications. Particularly, the objective is to verify in the field and possibly improve the performance of the novel satellite access technique BLQS-CDMA (Band Limited Quasi-Synchronous-Code Division Multiple Access), which is proposed as baseline for the MSBN.

Luzdemateo, Maria; Johns, Simon; Dothey, Michel; Vanhimbeeck, Carl; Deman, Ivan; Wery, Bruno

1993-01-01

293

Optimising mobile phone self-location estimates by introducing beacon characteristics to the algorithm  

Microsoft Academic Search

Positioning technologies that use global system for mobile communication (GSM) networks for location estimation (such as the privacy observant location system (POLS) and the place lab framework) lack the accuracy that other positioning technologies like the global positioning system (GPS) have. GPS receivers are most of the time capable of placing a person within 10 m of a known location.

Kevin Curran; Sebastian Hubrich

2009-01-01

294

History of Antenna Technology for Mobile Communications in Korea  

NASA Astrophysics Data System (ADS)

In this paper, we discuss the development of wireless and mobile communications in Korea, current technological trends, and the future outlook on technological developments. Since the introduction of the telegraph and the telephone in September 1885, Korea's wired and wireless communications industry has consistently developed for over 100 years. Since 1984, upon the provision of the mobile telecommunications service, the industry has seen drastic qualitative and quantitative growth in terms of both technical and economic aspects, which played a crucial role in the rapid growth of the digital industry in Korea. After the era of the analog cellular service based on the Advanced Mobile Phone System (AMPS), a precursor to the modern mobile service, Korea became the world's first country to commercialize Code Division Multiple Access (CDMA) in 1996 and succeeded in commercializing CDMA 2000 lx (IMT 2000) in 2001. With further developments in the mobile communication technology, the technology for antennas also saw drastic advancements. As the mobile antennas moved from the second to the third generation, they grew from external models to very small internal models. At the same time, they evolved into highly functional and high performance multiple band and wide band antennas. Furthermore, Korea was the first country to commercialize and offer the Wireless Broadband Internet (WiBro) service in 2006. By leading the wireless communications standardization and exerting remarkable efforts in research and development, Korea is consolidating its status as an Information Technology (IT) leader in the global market. The antenna's inherent importance will be further emphasized in the near future as it satisfies the performance and structural needs of portable terminals necessary for realizing the projected establishment of the ubiquitous world. It is thought that antenna technologies will not be limited to simple concepts as previously experienced but will utilize various kinds of materials that build the terminals' structure and framework. Moreover, studies will be performed with an emphasis on multiple band, multiple directivity, and ultra-wide band. Accordingly, antenna technologies to which new concepts are applied, such as SMART antenna and MIMO antenna technologies and meta-materials, will surely be effective alternatives.

Min, Kyeong-Sik; Park, Chul-Keun; Kang, Suk-Youb

295

Aeronautical Mobile Airport Communications System (AeroMACS)  

NASA Technical Reports Server (NTRS)

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

Budinger, James M.; Hall, Edward

2011-01-01

296

Marketing Innovation Strategy for Terminal Product of the Mobile Communications Industry Chain  

Microsoft Academic Search

In this article I first introduced the terminal product of mobile communications industry chain of our country, namely the information service. Based on the date of the increment of mobile phone users, the ratio of the value-added service revenue in the total business revenue, the value-added service market structure, I analyzed the terminal product market of the mobile communications industry

Zhang Shaojie; Wangxin; Wang Wenfeng

2009-01-01

297

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

E-print Network

The Interoperability Problem: Bringing together Mobile Agents and Agent Communication Languages is a central issue for both the mobile agents community and the wider agents community. Unfor- tunately is an issue that has been addressed in a limited man- ner by the mobile agents community. Agent communication

Finin, Tim

298

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

E-print Network

Mobile Agents Based Collective Communication: An Application to a Parallel Plasma Simulation lack in Mobile Agents systems even if mes- sage passing is always supported to grant communication benefit social ability and interactions of collaborative agents. Mobile Agents technology has been widely

Vlad, Gregorio

299

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

E-print Network

The Interoperability Problem: Bringing together Mobile Agents and Agent Communication Languages is a central issue for both the mobile agents community and the wider agents community. Unfor­ tunately is an issue that has been addressed in a limited man­ ner by the mobile agents community. Agent communication

Peng, Yun

300

A SIP-based OSGi Device Communication Service for Mobile Personal Area Networks  

E-print Network

A SIP-based OSGi Device Communication Service for Mobile Personal Area Networks Alan Brown, Mario This paper discusses the benefits of a proposed Session Initiation Protocol (SIP)-based device communication Service for deployment on a Mobile Open Services Gateway Initiative (OSGi) framework. Mobile OSGi

Kolberg, Mario

301

A digital platform for marketing communications in the mobile and social media space  

E-print Network

media. Keywords: digital marketing platform, mobile advertising, social media marketing, mobileA digital platform for marketing communications in the mobile and social media space Otto Petrovic for marketing communications developed during the last years. Functionalities of the platform are described

Boyer, Edmond

302

Communication Systems last lecture  

E-print Network

, power control and hand-over ­ Authentication and security #12;3 | 70 Communication Systems GSM of main GSM components ­ Authentication, Authorization, Access - Security issues will be handled ­ Authentication, Authorization, Access · In a public network like GSM the triple-A of authentication

Schindelhauer, Christian

303

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

E-print Network

WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 00: 1­17 (20xx manuscript, published in "Wireless Communications and Mobile Computing 11, 5 (2011) 567-582" #12;2 A) Communication Protocols for Vehicular Ad hoc Networks Arnaud Casteigts1 , Amiya Nayak1 , and Ivan Stojmenovic1 1

Paris-Sud XI, Université de

304

Mobile Interface for the Communication and Reference of DynamicTactical Information  

E-print Network

Mobile Interface for the Communication and Reference of DynamicTactical Information Modern mobile. It is not uncommon for today's `smartphones' to have voice communication, GPS capability, several wireless data of tasks rely heavily on geospatial data. Maps are a common, natural tool for communicating information

Wurtele, Eve Syrkin

305

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

E-print Network

WILEY WIRELESS COMMUNICATIONS AND MOBILE COMPUTING 1 DSP Implementation of a Bit Loading Algorithm COMMUNICATIONS AND MOBILE COMPUTING 2 Index Terms Adaptive wireless transceivers, multicarrier modulation, bit Wireless Communications and Networking Conference (WCNC), Las Vegas, Nevada, USA. This work was generously

Kansas, University of

306

A Provable-Security Mutual Authenticated Key Agreement Protocol for Mobile Communication  

Microsoft Academic Search

In the area of mobile communication security, a key agreement protocol with mutual authentication is very essential to the following secure sessions between communicators and more attentions are paid to the provability of the protocol security. Based on Blake-Wilson's work, the new notions of secure AK and AKC protocols are defined. An efficient authenticated key agreement protocol for mobile communication

Pan Heng; Li Jing-Feng; Zheng Qiu-Sheng

2008-01-01

307

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

308

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 presentation.

Wilson, Jeffrey D.; Kerczewski, Robert J.

2011-01-01

309

Design for Social Presence and Exploring Its Mediating Effect in Mobile Data Communication Services  

ERIC Educational Resources Information Center

The mobility, flexibility, convenience, and ubiquity of mobile data services (MDS) have contributed to their enormous growth and popularity with users. MDS allow users to communicate through mobile texting (mTexting), mobile Instant Messaging (mIM), multimedia messaging services (MMS), and email. A unique feature of MDS that enhances its

Ogara, Solomon Omondi

2011-01-01

310

QoS-driven adaptive resource allocation for mobile wireless communications and networks  

E-print Network

Quality-of-service (QoS) guarantees will play a critically important role in future mobile wireless networks. In this dissertation, we study a set of QoS-driven resource allocation problems for mobile wireless communications and networks...

Tang, Jia

2009-05-15

311

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

312

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

Microsoft Academic Search

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

Mikko V. J. Heikkinen; Sakari Luukkainen

2010-01-01

313

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

314

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

315

78 FR 56737 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...  

Federal Register 2010, 2011, 2012, 2013, 2014

...INTERNATIONAL TRADE COMMISSION [Investigation No. 337-TA-885] Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Commission Determination Not To Review an Initial Determination...

2013-09-13

316

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

317

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

E-print Network

Research Issues for Data Communication in Mobile Ad-Hoc Network Database Systems Leslie D. Fife, Le, servers have unlimited power and communicate with mobile hosts over a wireless connection. Mobile clients communicate with every other node. In addition to the issues associated with a mobile network, the power

Gruenwald, Le

318

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

E-print Network

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

Vardoulias, George

319

Smart Antenna Application in DS-CDMA Mobile Communication System  

NASA Astrophysics Data System (ADS)

This thesis examine the use of an equally-spaced linear adaptive antenna array at the mobile station for a typical Direct Sequence Code Division Multiple Access (DS-CDMA) cellular mobile communications system with forward error correction, with soft decision decoding is studied, We analyze the performance of a randomly positioned mobile terminal with a randomly orientated adaptive antenna array in the forward channel (base- station to mobile) of a multi-cell DS-CDMA system and established four performance% boundaries, Using the more conservative optimized array antenna performance boundary for the 2-, 3- and 4-element linear array, we compare the capacity and the performance% of different cellular systems under a range of shadowing conditions, with and without antenna sectoring at the base-station, and for various user capacities, using Monte Carlo simulation We further apply tapped-delay line (transversal filter) to each antenna element channel, to allow frequency dependent amplitude and phase adjustment for broadband signals, The performance of a DS-CDMA cellular system with a mobile terminal equipped with a linear array and a tapped-delay line is analyzed, It has been demonstrated that the optimization process has been extremely computationally expensive and hence minimum taps should be used for practical consideration, The results illustrated that, in general, for a 2-element linear array system, a 3-tap delay line would be sufficient to equalize the broadband signal while providing a similar performance level to that of a narrow-band adaptive array system In the case of a 3-element linear array system, a 2-tap delay line would suffice.

Ng, Kok K.

2002-09-01

320

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 Programme 113 References 119 #12;Mobile Communications for Medical Care ­ Final Report 4 21 April 2011 #12

Talbot, James P.

321

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

322

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

323

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

324

Study of p53 expression and post-transcriptional modifications after GSM-900 radiofrequency exposure of human amniotic cells.  

PubMed

The potential effects of radiofrequency (RF) exposure on the genetic material of cells are very important to determine since genome instability of somatic cells may be linked to cancer development. In response to genetic damage, the p53 protein is activated and can induce cell cycle arrest allowing more time for DNA repair or elimination of damaged cells through apoptosis. The objective of this study was to investigate whether the exposure to RF electromagnetic fields, similar to those emitted by mobile phones of the second generation standard, Global System for Mobile Communications (GSM), may induce expression of the p53 protein and its activation by post-translational modifications in cultured human cells. The potential induction of p53 expression and activation by GSM-900 was investigated after in vitro exposure of human amniotic cells for 24?h to average specific absorption rates (SARs) of 0.25, 1, 2, and 4?W/kg in the temperature range of 36.3-39.7?C. The exposures were carried out using a wire-patch cell (WPC) under strictly controlled conditions of temperature. Expression and activation of p53 by phosphorylation at serine 15 and 37 were studied using Western blot assay immediately after three independent exposures of cell cultures provided from three different donors. Bleomycin-exposed cells were used as a positive control. According to our results, no significant changes in the expression and activation of the p53 protein by phosphorylation at serine 15 and 37 were found following exposure to GSM-900 for 24?h at average SARs up to 4?W/kg in human embryonic cells. PMID:22767080

Bourthoumieu, Sylvie; Magnaudeix, Amandine; Terro, Faraj; Leveque, Philippe; Collin, Alice; Yardin, Catherine

2013-01-01

325

Assessing mobile phone communication utility preferences in a social support network  

Microsoft Academic Search

While it is generally accepted that the mobile cell phone has become ubiquitous within society for communicating, the actual use of the utilities on a phone have not been reported. Understanding how communication patterns are changing in society as a result of the mobile cell phone will enable the development and\\/or modification of existing cell phone utilities, the concept of

Elizabeth M. LaRue; Ann M. Mitchell; Lauren Terhorst; Hassan A. Karimi

2010-01-01

326

Smart-antenna systems for mobile communication networks. Part 1. Overview and antenna design  

Microsoft Academic Search

This paper focuses on the interaction and integration of several critical components of a mobile communication network using smart-antenna systems. This wireless network is composed of communicating nodes that are mobile, and its topology is continuously changing. One of the central motivations for this work comes from the observed dependence of the overall network throughput on the design of the

S. Bellofiore; C. A. Balanis; J. Foutz; A. S. Spanias

2002-01-01

327

Applications of antenna arrays to mobile communications. I. Performance improvement, feasibility, and system considerations  

Microsoft Academic Search

The demand for wireless mobile communications services is growing at an explosive rate, with the anticipation that communication to a mobile device anywhere on the globe at all times will be available in the near future. An array of antennas mounted on vehicles, ships, aircraft, satellites, and base stations is expected to play an important role in fulfilling the increased

LAL C. GODARA

1997-01-01

328

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

ERIC Educational Resources Information Center

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

Beaubrun, Ronald; Pierre, Samuel

2001-01-01

329

Control Freaks: How Online and Mobile Communication is Reshaping Social Contact  

E-print Network

Control Freaks: How Online and Mobile Communication is Reshaping Social Contact Naomi S. Baron controls to adjust fan speeds, to making purchases at vending machines with our mobile phones. [NOTE Control has long been a critical aspect of human interpersonal communication. We cross the street to avoid

Carlini, David

330

Abstract --In mobile radio communication systems using spread spectrum technology, an accurate estimate of the signal  

E-print Network

Abstract -- In mobile radio communication systems using spread spectrum technology, an accurate is usually done using a pseudo noise (PN) code ac- quisition algorithm to search for the correct propagation-SS) has recently been proposed for use in third generation mobile communications systems such as CDMA2000

Aloul, Fadi

331

An empirical assessment and application of SERVQUAL in mainland China's mobile communications industry  

Microsoft Academic Search

Purpose The purpose of this study is to assess the SERVQUAL instrument reliability and validity and apply the SERVQUAL instrument in China's mobile communication setting. Design\\/methodology\\/approach A mail survey was conducted at a major mobile communications company in mainland China. Instrument reliability and validity were examined. Exploratory and confirmatory factor analyses were conducted. Findings The adapted SERVQUAL

Fujun Lai; Joe Hutchinson; Dahui Li; Changhong Bai

2007-01-01

332

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

333

PHYSICAL REVIEW E 85, 016113 (2012) Consensus in networks of mobile communicating agents  

E-print Network

PHYSICAL REVIEW E 85, 016113 (2012) Consensus in networks of mobile communicating agents Andrea by the emission range of the agents and by their mobility, and we identify the corresponding scaling behaviors reference for a better understanding of the behavior of populations of mobile agents. DOI: 10.1103/Phys

Diaz-Guilera, Albert

334

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

E-print Network

WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2010; 10:547­558 Published A distributed MAC scheme supporting voice services in mobile ad hoc networks Hai Jiang1, , Ping Wang2 , H, University of Waterloo, Ontario, Canada Summary Future mobile ad hoc networks are expected to support voice

Jiang, Hai

335

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 Shaoxuan Wang, Sujit Dey Mobile System Design Lab, Dept. of Electrical and Computer Engineering University of California, San Diego {shaoxuan, dey}@ece.ucsd.edu Abstract--A new Cloud Mobile Gaming (CMG) approach, where

California at San Diego, University of

336

Conveying Route Information On Mobile Devices Using Communicative Acts William A Mackaness  

E-print Network

Conveying Route Information On Mobile Devices Using Communicative Acts William A Mackaness Simply displaying a map is far from sufficient when conveying route information on a mobile device/worry, and irritation. Given that mobile devices support a variety of media (non-linguistic auditory acts, spoken

337

23 M-Learning: The Educational Use of Mobile Communication Devices  

Microsoft Academic Search

This is a position paper which explores the use of mobile communication devices in teaching and learning. We especially undertake a crosswalk around the fast evolving field of mobile learning with a view of positioning it as new paradigm for learning. We deduce that successful development and implementation of any mobile learning solution requires a deep understanding of the learning

Paul Birevu Muyinda; Ezra Mugisa; Kathy Lynch

338

Optimized Communication using the SOAP Infoset For Mobile Multimedia Collaboration Applications  

E-print Network

Optimized Communication using the SOAP Infoset For Mobile Multimedia Collaboration Applications, there are performance limitations if we use the current SOAP approaches to integrate mobile applications with Web a SOAP Infoset preserving Flexible Representation and its specialization for mobile computing environment

339

76 FR 58537 - In the Matter of Certain Personal Data and Mobile Communications Devices and Related Software...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Mobile Communications Devices and Related Software; Notice of Commission Determination...Apple Inc., and its subsidiary NeXT Software, Inc., both of Cupertino, California...mobile communications devices and related software. 75 FR 17434 (Apr. 6, 2010)....

2011-09-21

340

77 FR 40399 - Qiao Xing Universal Resources, Inc., and Qiao Xing Mobile Communication Co., Ltd.; Order of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Xing Universal Resources, Inc., and Qiao Xing Mobile Communication Co., Ltd.; Order of Suspension of Trading July...information concerning the securities of Qiao Xing Mobile Communication Co., Ltd. (``QXM''), a British...

2012-07-09

341

How can we use mobile apps for disaster communications in Taiwan: Problems and possible practice  

Microsoft Academic Search

The growth rate of global smart phone in 2010 is as high as 78.1%, showing that smart phone gradually becomes the mainstream in the mobile phone market. Smart phone has the function of installing applications, provides users with more diversified mobile value-added services and will change users' communication habits in the future. Mobile communication follows the development trend of 3G

Sz Jie Sung

2011-01-01

342

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

343

Isolated and coupled superquadric loop antennas for mobile communications applications  

NASA Astrophysics Data System (ADS)

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

Jensen, Michael A.; Rahmat-Samii, Yahya

344

Speech coding at 4800 bps for mobile satellite communications  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

345

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

346

Isolated and coupled superquadric loop antennas for mobile communications applications  

NASA Technical Reports Server (NTRS)

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

Jensen, Michael A.; Rahmat-Samii, Yahya

1993-01-01

347

Wireless Communication Enhancement Methods for Mobile Robots in Radiation Environments  

E-print Network

In hostile environments such as in scientific facilities where ionising radiation is a dominant hazard, reducing human interventions by increasing robotic operations are desirable. CERN, the European Organization for Nuclear Research, has around 50 km of underground scientific facilities, where wireless mobile robots could help in the operation of the accelerator complex, e.g. in conducting remote inspections and radiation surveys in different areas. The main challenges to be considered here are not only that the robots should be able to go over long distances and operate for relatively long periods, but also the underground tunnel environment, the possible presence of electromagnetic fields, radiation effects, and the fact that the robots shall in no way interrupt the operation of the accelerators. Having a reliable and robust wireless communication system is essential for successful execution of such robotic missions and to avoid situations of manual recovery of the robots in the event that the robot runs ...

Nattanmai Parasuraman, Ramviyas; Ferre, Manuel

348

Adaptive beamforming in a CDMA mobile satellite communications system  

NASA Technical Reports Server (NTRS)

Code-Division Multiple-Access (CDMA) stands out as a strong contender for the choice of multiple access scheme in these future mobile communication systems. This is due to a variety of reasons such as the excellent performance in multipath environments, high scope for frequency reuse and graceful degradation near saturation. However, the capacity of CDMA is limited by the self-interference between the transmissions of the different users in the network. Moreover, the disparity between the received power levels gives rise to the near-far problem, this is, weak signals are severely degraded by the transmissions from other users. In this paper, the use of time-reference adaptive digital beamforming on board the satellite is proposed as a means to overcome the problems associated with CDMA. 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 sources. Since CDMA is interference limited, the interference protection provided by the antenna converts directly and linearly into an increase in capacity. Furthermore, the proposed concept allows the near-far effect to be mitigated without requiring a tight coordination of the users in terms of power control. A payload architecture will be presented that illustrates the practical implementation of this concept. This digital payload architecture shows 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.

1993-01-01

349

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

350

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 13, NO. 6, JUNE 2014 3317 Enabling Mobile Traffic Offloading via  

E-print Network

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 13, NO. 6, JUNE 2014 3317 Enabling Mobile, IEEE Abstract--Green communications has received much attention recently. For mobile networks, the base is referred to as utilizing complementary communication networks to deliver mobile traffic, is a promising

Ansari, Nirwan

351

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

352

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

353

Tracking Vehicle in GSM Network to Support Intelligent Transportation Systems  

NASA Astrophysics Data System (ADS)

The penetration of GSM capable devices is very high, especially in Europe. To exploit the potential of turning these mobile devices into dynamic data acquisition nodes that provides valuable data for Intelligent Transportation Systems (ITS), position information is needed. The paper describes the basic operation principles of the GSM system and provides an overview on the existing methods for deriving location data in the network. A novel positioning solution is presented that rely on handover (HO) zone measurements; the zone geometry properties are also discussed. A new concept of HO zone sequence recognition is introduced that involves application of Probabilistic Deterministic Finite State Automata (PDFA). Both the potential commercial applications and the use of the derived position data in ITS is discussed for tracking vehicles and monitoring traffic flow. As a practical cutting edge example, the integration possibility of the technology in the SafeTRIP platform (developed in an EC FP7 project) is presented.

Koppanyi, Z.; Lovas, T.; Barsi, A.; Demeter, H.; Beeharee, A.; Berenyi, A.

2012-07-01

354

Video quality requirements for South African Sign Language communications over mobile phones  

E-print Network

Video quality requirements for South African Sign Language communications over mobile phones. But this robs the Deaf from the opportunity to communicate in their first language, Sign Language. Sign Language, being a visual language, does not translate well to the text-based communications available to them

Blake, Edwin

355

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

E-print Network

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

Mostofi, Yasamin

356

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

357

Communications and entertainment onboard a high-speed public transport system  

Microsoft Academic Search

This article discusses architectural design at the conceptual\\/functional level of communication and entertainment services onboard a high-speed public transport system, such as a high-speed train, a transoceanic cruise ship, or even a mid- to long-range airplane. Existing commercial mobile communication services, such as AMPS and GSM, are inaccessible to passengers onboard these public transport systems. A hierarchical architecture is laid

Kun-De Lin; Jin-Fu Chang

2002-01-01

358

Domestic mobile satellite communication system using 2.6/2.5 GHz band  

NASA Astrophysics Data System (ADS)

This paper describes domestic mobile satellite communication system concept using 2.6/2.5 GHz band. In this system a 1.85 m on-board satellite antenna covers the Japanese islands and the surrounding 200 nautical mile area. Two types of mobile terminals are considered, corresponding to voice and message services. For voice communication terminals, a 28 cm short backfire antenna is considered. For low bit rate (2.4 Kbps) message communication terminals, a 4.5 dB gain doughnut beam antenna without tracking is considered. Also, characteristics of the experimental mobile terminal antenna are described.

Egami, S.; Yamada, Y.; Nakajima, S.; Nakamae, M.

359

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

360

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

361

LOOPUS Mob-D: System concept for a public mobile satellite system providing integrated digital services for the Northern Hemisphere from an elliptical orbit  

NASA Technical Reports Server (NTRS)

A new concept for a satellite based public mobile communications system, LOOPUS Mob-D, is introduced, whereby most of the classical problems in mobile satellite systems are approached in a different way. The LOOPUS system will offer a total capacity of 6000 high rate channels in three service areas (Europe, Asia, and North America), covering the entire Northern Hemisphere with a set of group special mobile (GSM) compatible mobile services, eventually providing the 'office in the car'. Special characteristics of the LOOPUS orbit and the communications network architecture are highlighted.

Kuhlen, H.; Horn, P.

1990-01-01

362

A Study on the Role of Mobile Phone Communication in Tuberculosis DOTS Treatment  

PubMed Central

Background: Every year, a lot of Tuberculosis (TB) patients undergo Directly Observed Treatment Short-course (DOTS) in Salem city, one of the high TB districts in South India. Mobile phone usage among these patients and health workers is common. Mobile phone communication has a great potential in TB treatment. Objectives: To analyze the mobile phone usage and its effectiveness in TB DOTS treatment. Materials and Methods: A cross-sectional survey with 150 TB patients was followed by a focus group discussion with treatment supervisors, DOTS providers, and health workers. Results: Majority of patients use mobile phones to make calls to health workers to clarify their doubts on side effects, food, and symptoms of the disease. TB treatment supervisors effectively use mobile phones to counsel patients to adhere to the treatment regimen. Patients see mobile phones as a useful communication tool in TB treatment though they prefer direct interpersonal communication with health workers. Though the mobile ownership is 68% among the TB patients, many of them are not able to send text messages or read messages in English. Conclusion: Mobile phone possession and usage is high among the patients. Patients need to be trained to use mobile phone features such as alarm, voice mail, and interactive voice response. Incentives like free talk time and short message service (SMS) will encourage patients to communicate frequently with health workers, thereby, increasing the chances of better adherence to DOTS. SMS could be made available in the regional languages. PMID:24302824

Elangovan, R; Arulchelvan, S

2013-01-01

363

IMT-2000 Satellite Standards with Applications to Mobile Air Traffic Communications Networks  

NASA Technical Reports Server (NTRS)

The International Mobile Telecommunications - 2000 (IMT-2000) standard and more specifically the Satellite component of it, is investigated as a potential alternative for communications to aircraft mobile users en-route and in terminal area. Its application to Air Traffic Management (ATM) communication needs is considered. A summary of the specifications of IMT-2000 satellite standards are outlined. It is shown via a system research analysis that it is possible to support most air traffic communication needs via an IMT-2000 infrastructure. This technology can compliment existing, or future digital aeronautical communications technologies such as VDL2, VDL3, Mode S, and UAT.

Shamma, Mohammed A.

2004-01-01

364

Directedness of information flow in mobile phone communication networks  

E-print Network

Without having direct access to the information that is being exchanged, traces of information flow can be obtained by looking at temporal sequences of user interactions. These sequences can be represented as causality trees whose statistics result from a complex interplay between the topology of the underlying (social) network and the time correlations among the communications. Here, we study causality trees in mobile-phone data, which can be represented as a dynamical directed network. This representation of the data reveals the existence of super-spreaders and super-receivers. We show that the tree statistics, respectively the information spreading process, are extremely sensitive to the in-out degree correlation exhibited by the users. We also learn that a given information, e.g., a rumor, would require users to retransmit it for more than 30 hours in order to cover a macroscopic fraction of the system. Our analysis indicates that topological node-node correlations of the underlying social network, while ...

Peruani, Fernando; 10.1371/journal.pone.0028860

2013-01-01

365

David Florida Laboratory: Support for mobile satellite communications  

NASA Technical Reports Server (NTRS)

The comprehensive integration and environmental (including RF) test facilities of the Canadian Space Agency's David Florida Laboratory (CSA)(DFL) were used extensively for the MSAT Program. Following a description of the facilities, the paper outlines their application to the qualification of the two MSAT satellites following an overview of the test plan. Particular emphasis is given to passive intermodulation measurement (PIM) demands, which for the MSAT satellites, contributed to the need to extend the anechoic chamber. The extended chamber was also used for an EMC test and SAR signature test of the RADARSAT satellite. The DFL's facilities are being used for additional aspects of mobile satellite communications. One shielded anechoic Extra High Frequency (EHF) chamber and associated test equipment are employed predominantly for measuring the performance of the IRIDIUM satellites' Engineering Model Gateway Moveable Antennas (EM)(GMA). Other chambers are used for testing aeronautical antennas on behalf of Inmarsat. Still others combine thermal and PIM testing. The paper concludes with a review of the test requirements of evolving satcom missions such as Inmarsat Aero-1.

Dumoulin, Jean-Guy; Mamen, Rolf

1995-01-01

366

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

367

Effects of GSM-modulated 900 MHz radiofrequency electromagnetic fields on the hematopoietic potential of mouse bone marrow cells.  

PubMed

Studies describing the influence of radiofrequency electromagnetic fields on bone marrow cells (BMC) often lack functional data. We examined the effects of in vivo exposure to a Global System for Mobile Communications (GSM) modulated 900 MHz RF fields on BMC using two transplantation models. X-irradiated syngeneic mice were injected with BMC from either RF-field-exposed, sham-exposed or cage control mice. Twelve weeks after transplantation, no differences in thymocyte number, frequency of subpopulations and cell proliferation were found in mice receiving BMC from either group. Also, in the spleen cell number, percentages of B/T cells, B/T-cell proliferation, and interferon ? (IFN-?) production were similar in all groups. In parallel, a mixture of BMC from congenic sham- and RF-exposed mice were co-transplanted into lymphopenic Rag2 deficient mice. BMC from RF-exposed and sham-exposed mice displayed no advantage or disadvantage when competing for the replenishment of lymphatic organs with mature lymphocytes in Rag2 deficient mice. This model revealed that BMC from sham-exposed and RF-exposed mice were less efficient than BMC from cage control mice in repopulating the thymus, an effect likely due to restraint stress. In conclusion, our results showed no effects of in vivo exposure to GSM-modulated RF-fields on the ability of bone marrow (BM) precursors to long-term reconstitute peripheral T and B cell compartments. PMID:25256206

Rosado, Maria Manuela; Nasta, Francesca; Prisco, Maria Grazia; Lovisolo, Giorgio Alfonso; Marino, Carmela; Pioli, Claudio

2014-12-01

368

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

369

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

370

Traffic Analysis for Exposure Assessment in Mobile Zaher Mahfouz*, +  

E-print Network

public daily exposure to mobile telephony signals, namely GSM900, GSM1800, UMTS2100 and HSDPA (transmitted power, modulations, bandwidth, power control, data rate, transmission...) and its access mode like been investigated. In [5], it has been shown that the fields emitted from GSM900 systems are higher

Boyer, Edmond

371

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

Microsoft Academic Search

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

Ingo Vogelsang

2010-01-01

372

Enforcement of Communications Policies in Software Agent Systems through Mobile Code  

Microsoft Academic Search

This paper introduces the use of mobile agents as the mechanism for policy enforcement in multi-agent multi- domain systems. The focus is on the effective application of communication policies in the setup and maintenance of spanning data streams that cross multiple hosts in different domains. We have designed and implemented a mobile agent based framework (FlexFeed) that works in concert

Niranjan Suri; Marco M. Carvalho; Jeffrey M. Bradshaw; Maggie R. Breedy; Thomas B. Cowin; Paul T. Groth; Raul Saavedra; Andrzej Uszok

2003-01-01

373

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

374

A Comparison of Some Channel Assignment Strategies in Large-Scale Mobile Communications Systems  

Microsoft Academic Search

When more than one radio channel is available to serve a mobile customer in a large-scale mobile communications system the strategy used to make the assignment has an effect on system performance. Performance characteristics for five different assignment strategies obtained from a computer simulation are compared in this paper. It was found that the strategy that chooses a channel to

D. Cox; D. Reudink

1972-01-01

375

Application of antenna arrays to mobile communications. II. Beamforming and direction-of-arrival considerations  

Microsoft Academic Search

Array processing involves manipulation of signals induced on various antenna elements. Its capabilities of steering nulls to reduce cochannel interferences and pointing independent beams toward various mobiles, as well as its ability to provide estimates of directions of radiating sources, make it attractive to a mobile communications system designer. Array processing is expected to play an important role in fulfilling

LAL C. GODARA

1997-01-01

376

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

E-print Network

Wireless Networks 5 (1999) 467­477 467 Active tracking: Locating mobile users in personal communication service networks Hanoch Levy and Zohar Naor Department of Computer Science, School of Mathematics, Tel Aviv University, Tel Aviv 69978, Israel The problem of tracking mobile users in Personal

Levy, Hanoch

377

Phased Arrays of Ground and Airborne Mobile Terminals for Satellite Communications  

NASA Technical Reports Server (NTRS)

Phased array antenna is beginning to play an important in the arena of mobile/satellite communications. Two examples of mobile terminal phased arrays will be shown. Their technical background, challenges, and cost drivers will be discussed. A possible solution to combat some of the deficiencies of the conventional phased array by exploiting the phased reflectarray technology will be briefly presented.

Huang, John

1996-01-01

378

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

379

Human mobility models and opportunistic communications system design  

Microsoft Academic Search

In this paper, we seek to improve understanding of the structure of human mobility, with a view to using this for designing algorithms for the dissemination of data among mobile users. We analyse community structures and node centrality from the human mobility traces and use these two metrics to design efficient forwarding algorithms in terms of delivery ratio and delivery

Pan Hui; Jon Crowcroft

2008-01-01

380

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

381

Motivations for using the mobile phone for mass communications and entertainment  

Microsoft Academic Search

This study draws on the uses and gratifications framework to examine expanded use of a hybrid mediumthe mobile phonefor mass communications and entertainment. Results of a telephone survey of 208 users show different motiva- tions predict diverse uses of the mobile phone. Instrumental use motives drive the use of the mobile phone for news-seeking and Web-surfing. Further, the motive of

Ran Wei

2008-01-01

382

SAR Assessment and Analysis of Cumulative Body Exposure to Multi Transmitters from a Mobile Phone  

E-print Network

all possible simultaneous transmission from a mobile phone. The considered signals are GSM900, GSM1800 has its proper behavior (transmitted power, power control, data rate, bandwidth, modulations, duty

Paris-Sud XI, Université de

383

Mobile communication, public participation and e-governance in China: a case study of Xiamen anti-PX demonstration  

Microsoft Academic Search

China has become the biggest mobile communication carrier in the world since 2001. Advanced technologies create a communication revolution, and the individual, through the advent of mobile media, has become an active participant in this process. This study investigates the mobile phone's impact upon the developments of public participation, social inclusion and citizenship through the case study of Xiamen PX

Liu Jun; Zhao Hui

2010-01-01

384

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-jrg Vgel; Jrg Eberspche

1999-01-01

385

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

386

Proposition of a communication system used in mobility by users with physical disabilities, focus on  

E-print Network

on cerebral palsy with athetoid problems Yohan Guerrier, Christophe Kolski Univ Lille Nord de France, F-59000 system of communication for people with cerebral palsy (CP) with athetoid problems. These people have; mobility; Disabled user; Cerebral palsy (CP); Slurred speech; Communication support I. INTRODUCTION

Paris-Sud XI, Université de

387

Using mobile communication technology in high school education: Motivation, pressure, and learning performance  

Microsoft Academic Search

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 inter- action between the student and the instructor and improving learning efficiency. Social presence and information richness theory was applied to analyze the media and their impacts on the instruction process firstly.

Pei-luen Patrick Rau; Qin Gao; Li-mei Wu

2008-01-01

388

WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2011; 11:829842  

E-print Network

online 30 October 2009 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/wcm.864 SPECIALWIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2011; 11:829­842 Published.K. 3 Center for Communication Systems, School of Engineering, University of Durham, Durham, DH1 3LE, U

Wang, Cheng-Xiang

389

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

390

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

PubMed

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

Guinaldo, Mara; Fbregas, Ernesto; Farias, Gonzalo; Dormido-Canto, Sebastin; Chaos, Dictino; Snchez, Jos; Dormido, Sebastin

2013-01-01

391

A Mobile Robots Experimental Environment with Event-Based Wireless Communication  

PubMed Central

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

Guinaldo, Mara; Fbregas, Ernesto; Farias, Gonzalo; Dormido-Canto, Sebastin; Chaos, Dictino; Snchez, Jos; Dormido, Sebastin

2013-01-01

392

Optimization of Wireless Resources for Personal Communications Mobility Tracking*  

E-print Network

, Michael L. Honig and Ken Steiglitz ABSTRACT In personal communications applications, users communicate via, Northwestern University, Evanston, IL 60208. The work of Ken Steiglitz was partly supported by NSF Grant MIP

Steiglitz, Kenneth

393

On the design of security protocols for mobile communications  

Microsoft Academic Search

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

Yi Mu; Vijay Varadharajan

1996-01-01

394

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

395

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 7, NO. 7, JULY 2008 2705 A Secure Mobile Electronic Payment Architecture  

E-print Network

applications come with the emergence of electronic trading (mobile commerce or m-commerce), hence good secureIEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, VOL. 7, NO. 7, JULY 2008 2705 A Secure Mobile-added mobile applications. In order to attract more customers to such mobile applications, a solid, secure

Latchman, Haniph A.

396

Need for, and financial feasibility of, satellite-aided land mobile communications  

NASA Technical Reports Server (NTRS)

Questions regarding the role of a mobile-satellite system in augmenting the terrestrial communications system are considered, and a market assessment study is discussed. Aspects of an investment analysis are examined, taking into account a three phase financial study of four postulated land Mobile Satellite Service (LMSS) systems, project profitability evaluation methods, risk analysis methods, financial projections, potential investor acceptance standards, and a risk analysis. It is concluded that a satellite augmented terrestrial mobile service appears to be economically and technically superior to a service depending exclusively on terrestrial systems. The interest in the Mobile Satellite Service is found to be worldwide, and the ground equipment market is potentially large.

Castruccio, P. A.; Marantz, C. S.; Freibaum, J.

1982-01-01

397

UNIVERSITE DE NICE-SOPHIA ANTIPOLIS UFR SCIENCES  

E-print Network

)........................................................................................................................18 2.1 Standard GSM (Global System for Mobile communications)......................................................................................................17 2. Le GSM (2G............................................................................................19 2.3 Architecture du rseau GSM

Paris-Sud XI, Universit de

398

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

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

399

Mobilized by Mobile Media -- China's Transitional Communication Order, Societal Changes and Citizenship1  

Microsoft Academic Search

Digital technology has expanded mobile phone's potential from a talking device to increasingly the weapons against authoritarian rule and censorship. After eighteen years of development, the number of mobile users in China had surpassed 659 million, an average of one in less than two people. As the content is largely unknowable, unpredictable and unregulated, mobile media succeeds in breaching the

LIU Jun

400

Simulation of Rayleigh-faded mobile-to-mobile communication channels  

Microsoft Academic Search

Mobile-to-mobile channels find increasing applications in futuristic intelligent transport systems, ad hoc mobile wireless networks, and relay-based cellular networks. Their statistical properties are quite different from typical cellular radio channels, thereby requiring new methods for their simulation. This paper proposes a \\

Chirag S. Patel; Gordon L. Stber; Thomas G. Pratt

2005-01-01

401

Wireless Communications  

NSDL National Science Digital Library

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

Leske, Cavin.

402

Announcement/Subscription/Publication: Message Based Communication for Heterogeneous Mobile Environments  

NASA Astrophysics Data System (ADS)

Many tasks in smart environments can be implemented using message based communication paradigms that decouple applications in time, space, synchronization and semantics. Current solutions for decoupled message based communication either do not support message processing and thus semantic decoupling or rely on clearly defined network structures. In this paper we present ASP, a novel concept for such communication that can directly operate on neighbor relations between brokers and does not rely on a homogeneous addressing scheme or anymore than simple link layer communication. We show by simulation that ASP performs well in a heterogeneous scenario with mobile nodes and decreases network or processor load significantly compared to message flooding.

Ristau, Henry

403

Time as a limited resource: Communication Strategy in Mobile Phone Networks  

E-print Network

We used a large database of 9 billion calls from 20 million mobile users to examine the relationships between aggregated time spent on the phone, personal network size, tie strength and the way in which users distributed their limited time across their network (disparity). Compared to those with smaller networks, those with large networks did not devote proportionally more time to communication and had on average weaker ties (as measured by time spent communicating). Further, there were not substantially different levels of disparity between individuals, in that mobile users tend to distribute their time very unevenly across their network, with a large proportion of calls going to a small number of individuals. Together, these results suggest that there are time constraints which limit tie strength in large personal networks, and that even high levels of mobile communication do not fundamentally alter the disparity of time allocation across networks.

Miritello, Giovanna; Lara, Rubn; Martnez-Lpez, Roco; Roberts, Sam G B; Dunbar, Robin I M

2013-01-01

404

Unsupervised user similarity mining in GSM sensor networks.  

PubMed

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

405

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

406

m-LoCoS UI: A Universal Visible Language for Global Mobile Communication  

NASA Astrophysics Data System (ADS)

The LoCoS universal visible language developed by the graphic/sign designer Yukio Ota in Japan in 1964 may serve as a usable, useful, and appealing basis for a mobile phone application that can provide capabilities for communication and storytelling among people who do not share a spoken language. User-interface design issues including display and input are discussed in conjunction with prototype screens showing the use of LoCoS for a mobile phone.

Marcus, Aaron

407

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

408

Military Communications Satellite System Multiplies UHF Channel Capacity for Mobile Users  

Microsoft Academic Search

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

Z. Wadsworth

409

GSM-Railway as part of the European Rail Traffic Management System  

NASA Astrophysics Data System (ADS)

GSM-R is a vital component inside the ERTMS which is also an essential element of European Community rail projects; investment in equipping and the rolling stock with ERTMS could reach 5 billion eurodollars in the period 2007-2016. GSM-R is the result of over ten years of collaboration between the various European railway companies, the railway communication industry and the different standardization bodies. GSM-R provides a secure platform for voice and data communication between the operational staff of the railway companies including drivers, dispatchers, shunting team members, train engineers, and station controllers. It delivers advanced features such as group calls, voice broadcast, location based connections, and call pre-emption in case of an emergency, which significantly improves communication, collaboration, and security management across operational staff members. Taking into account the above mentioned, the paper will permit to audience to discover the GSM-R network architecture, services and applications proposed by this technology together with the future development and market situation due to the market liberalization.

Bibac, Ionut

2007-05-01

410

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

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

411

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

NASA Astrophysics Data System (ADS)

A large deployable antenna is essential for effective mobile communication satellites. This paper describes the key technologies needed for such an antenna, the development plan, and the characteristics of various scale models. The electrical scale models of the mesh reflector antenna and the mechanical models of the deployable reflector have been constructed to aid in antenna design. The ultimate goal is a deployable mesh reflector antenna with 30-m diameter. The measured performance of the scale models corresponds closely to the calculated performance. These results will be extremely useful for designing large deployable mesh reflector antennas for mobile communication satellites.

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

1992-03-01

412

Characteristics of scale models of large deployable mesh reflector antennas for mobile communications satellites  

NASA Astrophysics Data System (ADS)

In the land mobile satellite system (LMSS) using a geostationary platform (GPF), a 30 m diameter satellite antenna is desirable for small portable terminal communications. SCR has adopted two deployment types of antenna structure, the Hexa-Link Truss reflector and the Tetra-Triagonal Prism Truss (TETRUS) reflector, and has developed scale models of them. Both of them represent important aspects of large satellite antenna technology. This paper describes the SCR outline of a land mobile satellite communications system and the experimental results of the scale models. This research establishes the basic technical information necessary for the development of a 30 m diameter antenna and a conceptual GPF design.

Akaishi, Akira; Orikasa, Teruaki; Kashiki, Kanshiro; Okamoto, Teruki; Otsu, Yuichi; Satoh, Hideo

413

Characteristics of scale models of large deployable mesh reflector antenna for mobile communications satellites  

NASA Astrophysics Data System (ADS)

In the land mobile satellite system (LMSS) using a geostationary platform (GPF), a 30 m diameter satellite antenna is desirable for small portable terminal communications. SCR has adopted two deployment types of antenna structure, the Hexa-Link Truss reflector and the Tetra-Triagonal Prism Truss (TETRUS) reflector, and has developed scale models of them. Both of them represent important aspects of large satellite antenna technology. This paper describes the SCR outline of a land mobile satellite communications system and the experimental results of the scale models. This research establishes the basic technical information necessary for the development of a 30 m diameter antenna and a conceptual GPF design.

Akaishi, Akira; Orikasa, Teruaki; Kashiki, Kanshiro; Okamoto, Teruki; Otsu, Yuichi; Satoh, Hideo

1993-10-01

414

IEEE Communications Magazine July 199790 Rayleigh Fading Channels in Mobile  

E-print Network

communication system, a signal can travel from transmitter to receiver over multiple reflective paths changes in the propagating medium, such as varia- tions in the density of ions in the ionospheric layers

Howard, Sheryl

415

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

416

A communication protocol for mobile satellite systems affected by rain attenuation  

NASA Technical Reports Server (NTRS)

A communication protocol is described that has been developed as part of a K/Ka-band mobile terminal breadboard system to be demonstrated through NASA's Advanced Communications Technology Satellite (ACTS) in 1993. The protocol is aimed at providing the means for enhancing link availability and continuity by supporting real-time data rate selection and changes during rain events. Particular attention is given to the system architecture; types of links, connections, and packets; the protocol procedures; and design rationales.

Lay, Norman; Dessouky, Khaled

1992-01-01

417

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

Microsoft Academic Search

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

Bernard Sklar

1997-01-01

418

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

419

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

420

Effects of GSM 900 MHz on middle cerebral artery blood flow assessed by transcranial Doppler sonography.  

PubMed

Mobile phone use has increased worldwide but its possible effects on the brain remain unclear. The aim of the present study was to investigate the effect of acute exposure to a radio frequency electromagnetic field (RF EMF) generated by a mobile phone operating in the Global System for Mobile Communication (GSM) 900 MHz on cerebral blood flow. Twenty-nine volunteers attended two experimental sessions: a sham exposure session and a real exposure session in a cross-over double-blind study in which a mobile phone was positioned on the left side of the head. In one session, the mobile phone was operated without RF radiation (sham phone) and in the other study it was operated with RF radiation (real phone) for 20 min. Thus, each subject served as its own control. Middle cerebral artery blood flow was monitored noninvasively by transcranial Doppler sonography to measure middle cerebral artery blood flow velocity. Pulsatility index and resistance index were also evaluated. A voluntary breath holding physiological test was carried out as a positive control for testing cerebral vasoreactivity. Hemodynamic variables were recorded and analyzed before, during and after mobile phone exposure. No significant changes were detected in studied variables in middle cerebral arteries during sham or real exposure. In the exposed side the cerebral blood flow velocity, the pulsatility index and the resistance index during sham and real exposure were respectively: [61.9 1.3, 61.7 1.3 cm/s (P = 0.89)]; [0.93 0.03, 0.90 0.02 (P = 0.84)] and [0.58 0.01, 0.58 0.01 (P = 0.96)] at baseline; and [60.6 1.3, 62 1.6 cm/s (P = 0.40)]; [0.91 0.03, 0.87 0.03 (P = 0.97)]; [0.57 0.01, 0.56 0.01 (P = 0.82)] after 20 min of exposure. Twenty minutes of RF exposure to a mobile phone does not seem to affect the cerebral circulation. PMID:23106209

Ghosn, Rania; Thurczy, Gyrgy; Loos, Nathalie; Brenet-Dufour, Valrie; Liabeuf, Sophie; de Seze, Ren; Selmaoui, Brahim

2012-12-01

421

On Applications of Self-Phased Array Antennas to Mobile Communications Sergey L. Loyka and Vladimir I. Mordachev  

E-print Network

On Applications of Self-Phased Array Antennas to Mobile Communications Sergey L. Loyka and Vladimir 220027, Republic of Belarus 375-(0)17-2398994, e-mail: loyka@nemc.belpak.minsk.by Abstract A simple used in mobile communication systems by the use of a self-phased array antenna which employs a pilot

Loyka, Sergey

422

75 FR 17434 - In the Matter of Certain Personal Data and Mobile Communications Devices and Related Software...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Mobile Communications Devices and Related Software; Notice of Investigation AGENCY: U...of Cupertino, California and NeXT Software, Inc. f/k/a NeXT Computer, Inc...mobile communications devices and related software by reason of infringement of...

2010-04-06

423

Improvement of the dropping probabilities in mobile communication networks by using guard channels protocol with delay of new user  

Microsoft Academic Search

There has been a gradual growth in the wireless Internet and the possibility that millions of users will soon access e-mail and Web pages on a cellular phone, PDA (personal digital assistant), or pager. As the wireless Internet and mixed data and voice services in cellular mobile communication systems spread, the QoS (quality of service) for cellular mobile communication systems

T. Okuda; T. Ideguchi; X. Tian

2004-01-01

424

Toll free mobile communication: overcoming barriers in maternal and neonatal emergencies in Rural Bangladesh  

PubMed Central

Background Toll free mobile telephone intervention to support mothers in pregnancy and delivery period was tested in one sub district of Bangladesh. Qualitative research was conducted to measure the changes of mobile phone use in increasing communication for maternal and neonatal complications. Methods In-depth interviews were conducted among twelve Community Skilled Birth Attendants and fourteen mothers along with their husbands prior to intervention. At intervention end, six Community Skilled Birth Attendants were purposively selected for in-depth interview. Semi structured interviews were conducted among all 27 Community Skilled Birth Attendants engaged in the intervention. One Focus Group Discussion was conducted with 10 recently delivered mothers. Thematic analysis and triangulation of different responses were conducted. Results Prior to intervention, Community Skilled Birth Attendants reported that mobile communication was not a norm. It was also revealed that poor mothers had poor accessibility to mobile services. Mothers, who communicated through mobile phone with providers noted irritability from Community Skilled Birth Attendants and sometimes found phones switched off. At the end of the project, 85% of mothers who had attended orientation sessions of the intervention communicated with Community Skilled Birth Attendants through mobile phones during maternal health complications. Once a complication is reported or anticipated over phone, Community Skilled Birth Attendants either made a prompt visit to mothers or advised for direct referral. More than 80% Community Skilled Birth Attendants communicated with Solution Linked Group for guidance on maternal health management. Prior to intervention, Solution Linked Group was not used to receive phone call from Community Skilled Birth Attendants. Community Skilled Birth Attendants were valued by the mothers. Mothers viewed that Community Skilled Birth Attendants are becoming confident in managing complication due to communication with Solution Linked Group. Conclusions The use of mobile technology in this intervention took a leap from simply rendering information to providing more rapid services. Active participation of service providers along with mothers accessibility motivated both the service providers and mothers to communicate through mobile phone for maternal health issues. These altogether made the shift towards adoption of an innovation. PMID:25015126

2014-01-01

425

Highly Efficient Digital Mobile Communications with a Linear Modulation Method  

Microsoft Academic Search

Although linear modulation methods can achieve high spectrum efficiency, very little attention has been directed to their use in mobile radio systems. This is mainly due to the fact that the nonlinearity of the transmitter power amplifier tends to spread the spectrum and thus eliminate any spectrum efficiency advantage gained through the use of linear modulation methods. In this paper,

YOSHIHIKO AKAIWA; Y. Nagata

1987-01-01

426

Acculturation and Communicative Mobility Among Former Soviet Nationalities.  

ERIC Educational Resources Information Center

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

Haarmann, Harald; Holman, Eugene

1997-01-01

427

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

428

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

429

User's perceived service quality of mobile communications: experience from Ethiopia  

Microsoft Academic Search

Purpose The purpose of this paper is to explore the causal relationship between service quality dimensions and overall service quality, and to identify service quality gaps as experienced by the subscribers of the mobile services of Ethiopian Telecommunication Corporation (ETC). Design\\/methodology\\/approach The seven modified dimensions of SERVQUAL, namely tangibles, reliability, responsiveness, empathy, assurance, network aspect, and convenience were

Rakshit Negi

2009-01-01

430

Performance evaluation of mobile wireless communication systems with link adaptation  

Microsoft Academic Search

The performance of key quality-of-service metrics for mobile cellular systems with link adaptation is evaluated by means of a teletraffic analysis. To our knowledge, no similar analysis considering link adaptation exists in the literature. In particular, novel mathematical expressions for inter-cell handoff call arrival rate, intracell handoff failure, and forced termination probabilities are derived.

Felipe A. Cruz-Prez; Genaro Hernndez-Valdez; Lauro Ortigoza-Guerrero

2003-01-01

431

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

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

432

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

433

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

E-print Network

Proc. of IEEE Wireless Communications and Networking Conference (WCNC), March 2003 Mobility: st@andrew.cmu.edu, peha@cmu.edu Abstract-- This study investigates mobility patterns in micro that a mobile device remains in a cell until the next handoff, and sign-on interarrival time, which

Peha, Jon M.

434

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

Microsoft Academic Search

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

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

1991-01-01

435

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

E-print Network

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

Mochizuki, Yujiro, 1973-

2006-01-01

436

No Such Effect? The Implications of Measurement Error in Self-Report Measures of Mobile Communication Use  

Microsoft Academic Search

Research on the social and psychological effects of mobile phone communication primarily is conducted using self-report measures of use. However, recent studies have suggested such measures of mobile phone communication use contain a significant amount of measurement error. This study compares the frequency of mobile phone use measured by self-report questions with error-free log data automatically collected through an Android

Tetsuro Kobayashi; Jeffrey Boase

2012-01-01

437

Modems for emerging digital cellular-mobile radio system  

NASA Technical Reports Server (NTRS)

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

Feher, Kamilo

1991-01-01

438

Communication as information-seeking: the case for mobile social software for developing regions  

Microsoft Academic Search

In this paper, we describe several findings from a multi-year, multi-method study of how information and communication technologies have been adopted and adapted in Central Asia. We have found that mobile phone usage is outpacing the rate of Internet adoption, that access to the Internet is primarily through public access sites carrying with it issues regarding privacy and surveillance, that

Beth E. Kolko; Emma J. Rose; Erica J. Johnson

2007-01-01

439

An infra-red sensory system with local communication for cooperative multiple mobile robots  

Microsoft Academic Search

Distributed autonomous robotic systems which are composed of multiple robotic agents have been attracted the attention of many researchers as a new strategy for flexible and robust robotic systems. For cooperative multiple mobile robots in distributed autonomous robotic systems, recognition of the dynamic environment is required. In this paper, a new sensory system with local communication functionality is developed utilizing

S. Suzuki; H. Asama; A. Uegaki; S. Kotosaka; T. Fujita; A. Matsumoto; H. Kaetsu; I. Endo

1995-01-01

440

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

E-print Network

temperature, pressure, and camera with inputs for water chemistry sensors. Because the nodes are lightThe DRL Underwater Sensor Network: Supporting Dual Communications, Sensing, and Mobility Iuliu Vasilescu, Carrick Detweiler and Daniela Rus We propose to demonstrate the underwater sensor network

Farritor, Shane

441

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 the Unmanned Aerial Vehicle (UAV) Ad-Hoc net- work, the layered architecture is not flexible enough to achieve for Unmanned Aerial Vehicle (IMAC UAV). As for the routing protocol, We developed the Optimized Link State

Dong, Liang

442

Researching on Communication Efficiency for the Mobile Physiological Information Monitor System Based on Zigbee  

Microsoft Academic Search

This paper designs one mobile physiological information monitor system based on the ZigBee protocol. The hardware structure is presented. The network communication characteristic of this system was analyzed. The paper points out the disadvantage of the connection method in the ZigBee protocol. One improved connection method is proposed. Through carries on the comparison and the simulation to the routing mechanism

Teng Jiao; Kun Zhang; Yang Zhang; Hua Wang; Xinya Zhu; Xiuzhen Dong

2009-01-01

443

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

E-print Network

WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2009; 9:705717 Published, , Shaohua Wu2 and Naitong Zhang2 1 Department of Electrical and Computer Engineering, University of Alberta of Electrical and Computer Engineering, University of Alberta, Canada. E-mail: hai

Jiang, Hai

444

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

445

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

E-print Network

. The convergence of social networking, advanced smartphones, and stable network infrastructures brings us a pervaIEEE Wireless Communications · February 2014 331536-1284/14/$25.00 © 2014 IEEE MOBILE SOCIAL NETWORKS INTRODUCTION As reported by ComScore [1], social networking sites such as Facebook and Twitter

Shen, Xuemin "Sherman"

446

A Spectral-Based Analysis of Priority Channel Assignment Schemes in Mobile Cellular Communication Systems  

Microsoft Academic Search

In this paper we consider a queueing system with two arrival streams with application to mobile cellular communications systems is considered in this paper. Stream 1 is considered to require a higher priority to access the server than stream 2. On the other hand, while stream 2 is handled following a delay model, stream 1 has stringent constraints with regard

Vicent Pla; Vicente Casares Giner

2005-01-01

447

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

448

A Hybrid Channel Assignment Scheme in Large-Scale, Cellular-Structured Mobile Communication Systems  

Microsoft Academic Search

This paper considers the problem of channel assignment in mobile communication systems, where the service area is divided in hexagonal cells. In particular, a Hybrid Channel Assignment Scheme is studied and certain results are obtained using GPSS simulation of a model 40-cell system.

T. Kahwa; N. Georganas

1978-01-01

449

A new frequency channel assignment algorithm in high capacity mobile communication systems  

Microsoft Academic Search

A new algorithm for frequency channel assignment in mobile radio communication is proposed. The algorithm uses flexible fixed channel assignment which enables the calls having all their nominal channels busy to borrow channels from the neighboring cells provided that co-channel interference will not result. The borrowed channel cannot be used in three interfering cells; therefore reassignment strategy is used when

S. M. Elnoubi; R. Singh; S. C. Gupta

1982-01-01

450

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

451

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 Hggman

2001-01-01

452

An efficient communication strategy for mobile agent based distributed spatial data mining application  

NASA Astrophysics Data System (ADS)

An efficient communication strategy is proposed in this paper, which aims to improve the response time and availability of mobile agent based distributed spatial data mining applications. When dealing with decomposed complex data mining tasks or On-Line Analytical Processing (OLAP), mobile agents authorized by the specified user need to coordinate and cooperate with each other by employing given communication method to fulfill the subtasks delegated to them. Agent interactive behavior, e.g. messages passing, intermediate results exchanging and final results merging, must happen after the specified path is determined by executing given routing selection algorithm. Most of algorithms exploited currently run in time that grows approximately quadratic with the size of the input nodes where mobile agents migrate between. In order to gain enhanced communication performance by reducing the execution time of the decision algorithm, we propose an approach to reduce the number of nodes involved in the computation. In practice, hosts in the system are reorganized into groups in terms of the bandwidth between adjacent nodes. Then, we find an optimal node for each group with high bandwidth and powerful computing resources, which is managed by an agent dispatched by agent home node. With that, the communication pattern can be implemented at a higher level of abstraction and contribute to improving the overall performance of mobile agent based distributed spatial data mining applications.

Han, Guodong; Wang, Jiazhen

2005-11-01

453

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

454

RBHS Chancellor Policy Policy Name: Student Use of Personally Owned Mobile Communication Devices/Recording Devices  

E-print Network

Assistant (PDA), MP3 player, headphone, Bluetooth device, or any other wireless device that could be used Devices/Recording Devices Approval Authority: RBHS Chancellor Originally Issued: Revisions: 6/20/2013 1 of University-Accessed Electronic Information Systems B. Issuance and Use of Mobile Communications Devices 3

Neimark, Alexander V.

455

Characteristics of scale models of large deployable mesh reflector antenna for mobile communications satellites  

Microsoft Academic Search

In the land mobile satellite system (LMSS) using a geostationary platform (GPF), a 30 m diameter satellite antenna is desirable for small portable terminal communications. SCR has adopted two deployment types of antenna structure, the Hexa-Link Truss reflector and the Tetra-Triagonal Prism Truss (TETRUS) reflector, and has developed scale models of them. Both of them represent important aspects of large

Akira Akaishi; Teruaki Orikasa; Kanshiro Kashiki; Teruki Okamoto; Yuichi Otsu; Hideo Satoh

1993-01-01

456

Characteristics of scale models of large deployable mesh reflector antennas for mobile communications satellites  

Microsoft Academic Search

In the land mobile satellite system (LMSS) using a geostationary platform (GPF), a 30 m diameter satellite antenna is desirable for small portable terminal communications. SCR has adopted two deployment types of antenna structure, the Hexa-Link Truss reflector and the Tetra-Triagonal Prism Truss (TETRUS) reflector, and has developed scale models of them. Both of them represent important aspects of large

Akira Akaishi; Teruaki Orikasa; Kanshiro Kashiki; Teruki Okamoto; Yuichi Otsu; Hideo Satoh

1993-01-01

457

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

Microsoft Academic Search

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

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

1992-01-01

458

DESIGN AND IMPLEMENTATION OF A CDMA TRANSMITTER FOR MOBILE CELLULAR COMMUNICATIONS  

Microsoft Academic Search

th 2001 and accepted September 8 th 2001 ABSTRACT In this work we describe the design and implementation of a CDMA transmitter with application on thi rd generation mobile and personal communication systems. We present several experimental results. RESUMEN En este trabajo se describe el diseo e implementacin de un transmisor CDMA con una aplicacin en sistemas mviles y personales

R. Muraoka; D. Covarrubias; A. Arvizu; J. Mendieta

2001-01-01

459

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

460

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

461

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

Microsoft Academic Search

The communication channel between the MARECS satellite at 26W 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

462

Steerable L-band antenna for land mobile voice communication terminal  

NASA Astrophysics Data System (ADS)

The ESA is developing an EMS (European Mobile System) land mobile voice communication system. Two steerable prototype antennas were developed for an EMS mobile voice communication terminal. The first one is a rotating antenna consisting of two OTA (One Turn Antenna) elements. The feed network generates two separate beams slightly shifted from the boresight. The tracking is based on level difference measurements from these two beams. The mechanical rotation is accomplished by the aid of a step motor. The acquisition and tracking are controlled by a microprocessor. The second antenna is a fully electronic array consisting of 12 OTA elements locating on a circle. The compact feed network gives rise to 24 separate beams in the azimuth plane. The tracking is based on the use of these multiple beams and the performance is enhanced by direction information from a digital compass. The design and performance of both these antennas are described.

Aurinsalo, J.; Hujanen, A.; Jongejans, A.; Marttila, I.; Mutanen, R.; Pitkaenen, I.; Tallqvist, S.

1991-10-01

463

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

464

Key Distribution Protocol for Digital Mobile Communication Systems  

Microsoft Academic Search

A key distribution protocol is proposed for digital mobile communi- cation systems. The protocol can be used with a star-type\\u000a network. User terminals have a constraint of being hardware-limited.\\u000a \\u000a Security of the protocol is discussed. A countermeasure is proposed to cope with a possible active attack by a conspiracy\\u000a of two opponents.

Makoto Tatebayashi; Natsume Matsuzaki; David B. Newman Jr.

1989-01-01

465

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

466

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

467

Information and Communication Technology and International Business Travel: Mobility Allies?  

Microsoft Academic Search

Like forecasts about the paperless office, technological solutions to the problem of international business travel continue to be deferred. As with the increased use of office paper, international business travel is defying predictions of its decline. There is growing evidence to suggest that business sectors which seem ideally placed to substitute information and communication technology (ICT) for travel, are actually

Paul Haynes

2010-01-01

468

ValueBased Communication Preservation for Mobile Robots  

E-print Network

of coordinated group behavior often must maintain communication between team members [3]. In the context, to create complex, behavior based robotic team behavior. While the VBCP behavior takes into account. Benning, Georgia. These tests showed promising results for the utility of this behavior in military

469

Value-Based Communication Preservation for Mobile Robots  

E-print Network

of coordinated group behavior often must maintain communication between team members [3]. In the context, to create complex, behavior- based robotic team behavior. While the VBCP behavior takes into account. Benning, Georgia. These tests showed promising results for the utility of this behavior in military

470

"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

471

Single Antenna Interference Rejection in GSM/EDGE Networks  

E-print Network

environment for efficient interference rejection. Keywords-- interference rejection; GSM system capacity I, the design of GSM systems was optimized for coverage and receiver development was focused on combating other users. However, the continued subscriber growth in GSM systems and the emergence of new multimedia

Arslan, Hseyin

472

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

473

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.

474

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

PubMed

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

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

2010-01-01

475

USE OF DIGITAL COMMUNICATIONS TO INFORM AND MOBILIZE CSPA-NYS Journal of Student Affairs, Volume 12, Issue 1, 2012 3  

E-print Network

USE OF DIGITAL COMMUNICATIONS TO INFORM AND MOBILIZE CSPA-NYS Journal of Student Affairs, Volume 12 Affairs Volume 12, Issue 1, 2012 #12;USE OF DIGITAL COMMUNICATIONS TO INFORM AND MOBILIZE CSPA-NYS Journal. For practitioners, the results of #12;USE OF DIGITAL COMMUNICATIONS TO INFORM AND MOBILIZE CSPA-NYS Journal

Suzuki, Masatsugu

476

iPads, Mobile Technologies, and Communication Applications: A Survey of Family Wants, Needs, and Preferences.  

PubMed

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

Meder, Allison M; Wegner, Jane R

2015-03-01

477

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

478

Should I Call Now? Understanding What Context is Considered When Deciding Whether to Initiate Remote Communication via Mobile Devices  

E-print Network

of mobile phone usage, where users recorded what context information they considered when making a call communication devices such as cell phones has enabled ubiquitous communication among family, friends frequency of a receiver's recent communication and distance from a receiver to her phone. We discuss

Madiraju, Praveen

479

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

E-print Network

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

Murray, Richard M.

480

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

E-print Network

-driven information and communication technologies, systems and products. Foreseeing importance and impact and Communication Technologies (ICT) are critical to India's future and underpin realization of the Vision 2020 to achieve the convergence of computing, communications and media technologies. Mobile computing and related

Melbourne, University of

481

Preliminary study on the induction of sperm head abnormalities in mice, Mus musculus, exposed to radiofrequency radiations from global system for mobile communication base stations.  

PubMed

The exposure of male mice to radiofrequency radiations from mobile phone (GSM) base stations at a workplace complex and residential quarters caused 39.78 and 46.03%, respectively, in sperm head abnormalities compared to 2.13% in control group. Statistical analysis of sperm head abnormality score showed that there was a significant (p < 0.05) difference in occurrence of sperm head abnormalities in test animals. The major abnormalities observed were knobbed hook, pin-head and banana-shaped sperm head. The occurrence of the sperm head abnormalities was also found to be dose dependent. The implications of the observed increase occurrence of sperm head abnormalities on the reproductive health of humans living in close proximity to GSM base stations were discussed. PMID:19816647

Otitoloju, A A; Obe, I A; Adewale, O A; Otubanjo, O A; Osunkalu, V O

2010-01-01

482

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

483

RESOLUTION: Reconfigurable Systems for Mobile Local Communication and Positioning  

Microsoft Academic Search

RESOLUTION aims at developing a wireless three-dimensional (3-D) local positioning system with measurement accuracy in the centimetre regime and real-time ability. A novel frequency modulated continuous wave (FMCW) radar principle with pulsed active reflector is employed. This High-Precision-Localisation-System (HPLS) will be implemented together with common WLAN systems that are used for data communication purposes. Due to its high data rate

Philippos Tragas; Antonis Kalis; Constantinos Papadias; Frank Ellinger; Ralf Eickhoff; Thomas Ussmuller; Ralf Mosshammer; Mario Huemer; Alexander Dabek; Dimosthenes Doumenis; Anastassios Kounoudes

2007-01-01

484

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

485

Downsizing Antenna Technologies for Mobile and Satellite Communications  

NASA Technical Reports Server (NTRS)

Due to the increasing and stringent functional requirements (larger capacity, longer distances, etc.) of modern day communication systems, higher antenna gains are generally needed. This higher gain implies larger antenna size and mass which are undesirable to many systems. Consequently, downsizing antenna technology becomes one of the most critical areas for research and development efforts. Techniques to reduce antenna size can be categorized and are briefly discussed.

Huang, J.; Densmore, A.; Tulintseff, A.; Jamnejad, V.

1993-01-01

486

Intercepting mobile communications: the insecurity of 802.11  

Microsoft Academic Search

The 802.11 standard for wireless networks includes a Wired Equivalent Privacy (WEP) protocol, used to protect link-layer communications from eavesdropping and other attacks. We have discovered several serious security flaws in the protocol, stemming from mis-application of cryptographic primitives. The flaws lead to a number of practical attacks that demonstrate that WEP fails to achieve its security goals. In this

Nikita Borisov; Ian Goldberg; David Wagner

2001-01-01

487

A New Mobile Text Telephony System Based on GPRS Communications  

Microsoft Academic Search

\\u000a Deaf people have had many difficulties to enjoy the advantages of modern telephone technology up to early days. Since Alexandre\\u000a Graham Bell invented the telephone in 1876, the first text telephones have needed almost a century to appear in the market\\u000a and to allow deaf people to communicate with others at long distances. In the same way, the design and

Santiago Aguilera; Sergio Jimnez; Daniel Bolaos; Mari-satur Torre; Jos Cols

2004-01-01

488

Pseudo-analog speech transmission in mobile radio communication systems  

Microsoft Academic Search

A low-complexity pseudo-analog speech transmission scheme is proposed for portable communications. It uses a speech coder based on adaptive differential pulse code modulation (ADPCM) in combination with a multilevel digital modulation technique such as M-ary DPSK or M-ary FSK and features low quantization noise, bandwidth efficiency, and robustness to transmission errors. A nonsymmetric M -ary DPSK scheme called skewed M-ary

Toshio Miki; Carl-Erik W. Sundberg; Nambi Seshadri

1993-01-01

489

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

NASA Astrophysics Data System (ADS)

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

Dixon, Cory

490

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

491

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

NASA Astrophysics Data System (ADS)

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.

Muthukumar, M.

2014-08-01

492

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

493

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

494

TO APPEAR IN WIRELESS COMMUNICATIONS AND MOBILE COMPUTING 1 Investigation of Multicast-Based Mobility Support  

E-print Network

-Based Mobility Support in All-IP Cellular Networks Andreas Festag1, Holger Karl2, and Adam Wolisz3 1 NEC Europe, Network Laboratories, festag@netlab.nec.de 2 University Paderborn, Fachgebebiet Rechnernetze, holger Andreas Festag and Holger Karl were working at Technical University Berlin, Telecommunication Networks

Wolisz, Adam

495

Performance analysis of replication ALOHA for fading mobile communications channels  

NASA Technical Reports Server (NTRS)

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

Yan, Tsun-Yee; Clare, Loren P.

1986-01-01

496

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

497

Towards Efficient Mobile M2M Communications: Survey and Open Challenges  

PubMed Central

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

498

A GSM-based surface meteorology network in service of improved African hydrological data assimilation and drought forecasting  

NASA Astrophysics Data System (ADS)

The last few years have witnessed an explosion in consumer electronics, particularly mobile computing and telephony. This technological development has led to profound changes in (i) the cost of mobile computing platforms, (ii) the ubiquity of data connectivity, particularly in rural locales, and (iii) the knowledge gap for non-specialists to design, manufacture, and program electronics. Our group has developed a small, inexpensive, modular electronics platform that accomodates any number or flavor of sensors, coupled to a GSM transceiver to allow machine-to-machine communications of realtime meteorological data of hydrological relevance. This effort has particular import in Sub-Saharan Africa, where there is a pressing need for improved drought monitoring and forecasting, but a sparse surface meteorology which poorly constrains the forecast model. We present here our design of the sensor package and data architecture, as well as an implementation of the data assimilation system using the Princeton African Drought Monitor and Forecast system. It is shown that due to the relatively large uncertainties in the prior condition, that surface meteorological and soil moisture observations reduce posterior ensemble spread considerably with potential to extend the forecast horizon and be useful for taking action on emerging drought.

Wolf, A.; Falusi, J.; Caylor, K. K.; Sheffield, J.; Wood, E. F.

2012-12-01

499

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

500

Maintaining communication link based on AODV routing protocol in mobile robot networks  

NASA Astrophysics Data System (ADS)

Wired computer networks are vital in modern life. However, these networks are extremely vulnerable to disaster or attack in emergency situations. Therefore, how to maintain communication link under emergency situations is very important. In this paper, we utilize a series of autonomous mobile slave robots which follow behind the lead robot and automatically stop where needed to maintain an ad hoc network for guaranteeing a link between the lead robot and its remote monitor/control station. To accomplish this target, an efficient communication protocol limitation mobile robots broadcast based on AODV (LMRB-AODV) is proposed for deployment in multi-robot system. After then the lead robot could carry service traffics to the monitor station under emergency situations through the communication link. At any instance, the lead robot has the ability to reclaim the relay robot(s) which are unneeded in the network to rejoin the convoy behind the lead robot and use it to extend the range of wireless communication when the radio frequency (RF) shortcuts are detected by the lead robot. All relay deployment and reclaiming strategy functions occur without the operator's involvement. Finally, we provide a comparative study of their performance in a number of different simulation environments. The results show that the proposed scheme is very efficient in maintaining communication link in wireless network.

Hu, Hui; Jiang, Hong

2007-12-01