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1

Forensics and the GSM Mobile Telephone System  

Microsoft Academic Search

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 can be obtained from the GSM system. This paper briefly explains the basics of the GSM system. Evidence items that can be obtained from the Mobile Equipment,

Svein Yngvar Willassen

2003-01-01

2

Downlink beamforming for cellular mobile communications (gsm system)  

Microsoft Academic Search

\\u000a Abstract  This paper is concerned with the possible implementation of antenna array processing at the base station of cellular radiomobile\\u000a networks, typically theGsm case. It first explains how those antennas would increase the capacity of such a network, processing uplink as well as downlink.\\u000a Then the attention is focused on downlink processing, that has been lesser studied than uplink processing and

Thierry ASTIr; Philippe Forster; Luc Féty; Sylvie Mayrargue

1998-01-01

3

The GSM base station system and the related equipment [mobile communications  

Microsoft Academic Search

A brief overview of the GSM (CEPT's Groupe Special Mobile) base station system (BSS) is given. The equipment needed to support this network entity and the specification of the equipment are presented. The use of the BSS equipment specification is described and the testing of the GSM base station systems is discussed. BSS network functions are outlined and the A-bis-interface

S. Hansen; P. Simmons

1988-01-01

4

GSM Mobile Phone Based Communication of Multimedia Information: A Case Study  

Microsoft Academic Search

Through a practical application, this paper studies the capacity of the GSM network, a wireless mobile phone network widely\\u000a used in Europe and some Asian countries, for transmitting multimedia data. The application is a client-server based automobile\\u000a security system which monitors the interior and exterior environments of the moving automobile by a computer equipped a digital\\u000a camera, a voice capturing

Y. S. Moon; H. C. Ho; Kenneth Wong

1999-01-01

5

Secure End-to-End Communication over GSM and PSTN Networks  

Microsoft Academic Search

GSM (Global System for Mobiles) is the most widely spread mobile communication system in the world. An important objective in mobile communication systems is secure speech communication. GSM suffers from various security weaknesses. The GSM voice traffic is secure outside the core network but it has no security over the core network. This system can be made thoroughly secure by

Saad Islam; Fatima Ajmal; Salman Ali; Jawad Zahid; Adnan Rashdi

2009-01-01

6

Long-term exposure to mobile communication radiation: an analysis of time-variability of electric field level in GSM900 downlink channels.  

PubMed

Interest for knowing long-term human exposure levels due to mobile communications has increased in the last years. It has been shown that short-term exposure assessment made under standard procedural restrictions is not reliable when it comes to conclusions on long-term exposure levels. The present work is the result of a several week analysis of time variability of electric field level inside traffic and control channels of the GSM900 mobile communication downlink band and it indicates that a temporal model to allow future predictions of exposure on the long run is obtainable. Collecting, processing and statistically analysing the data provide expression of the maximum and weighted field strengths and their evolution in time. Specific electromagnetic footprints of the channels have been extracted, differentiations between their characteristics have been emphasised and practical advice is provided, with the scope of contributing to the development of reliable procedures for long-term exposure assessment. PMID:22908352

Miclaus, Simona; Bechet, Paul; Gheorghevici, Marius

2012-08-19

7

Mobile Security - An Overview of GSM, SAT and WAP  

Microsoft Academic Search

Mobile networks have become a very attractive channel for the provision of electronic services, as they are available almost\\u000a anytime and anywhere. But for a service provider, there are several mobile communication standards to choose from. They differ\\u000a in market penetration, flexibility, and security.\\u000a \\u000a This paper gives a comparative overview of the security features of GSM, SIM Application Toolkit and

Malte Borcherding

1999-01-01

8

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

9

SMS Encryption for Mobile Communication  

Microsoft Academic Search

This paper deals with an SMS encryption for mobile communication. The transmission of an SMS in GSM network is not secure, therefore it is desirable to secure SMS by additional encryption. In the following text, there are compared differences in the use of symmetric and asymmetric cryptography for SMS transfer securing. In the next part, there is the description of

D. Lisonek; M. Drahansky

2008-01-01

10

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

11

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

Microsoft Academic Search

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

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

2000-01-01

12

IMPROVING SPEECH SECURITY AND AUTHENTICATION IN MOBILE COMMUNICATIONS  

Microsoft Academic Search

This paper points out certain weaknesses in the existing security system of Global System of Mobile Communications (GSM) and proposes a better security system for GSM. The proposed security system provides an authenticated session key distribution protocol between the authentication center (AUC) and the mobile station (MS) for every call attempt made by a MS. At the end of an

Chenthurvasan Duraiappan; Yuliang Zheng

13

A Data Modem for GSM Voice Channel  

Microsoft Academic Search

This paper introduces a novel approach to data communication over the global system for mobile communications (GSM) voice channel. It is based on the concept of ldquosymbolsrdquo-a set of predefined signals with finite bandwidths. Data are encoded into the symbols, and the symbols are voice coded as they were speech, modulated into the GSM signal, sent over the air, GSM

Christoph K. LaDue; Vitaliy V. Sapozhnykov; Kurt S. Fienberg

2008-01-01

14

Mobile communications - an overview  

Microsoft Academic Search

This article focuses on voice communications using mobile (cell) phones over mobile\\/cellular networks. The advances in processors, memory, signal processing, communication technologies, and several related techniques, personal mobile communications has witnessed tremendous growth. A typical mobile communication network consists of: mobile devices, BS, mobile switching centers, gateway mobile switching center. Cell phones communicate wirelessly with BSs. Base stations communicate with

S. R. Subramanya; B. K. Yi

2005-01-01

15

GSM Evolution to an IN Platform: Offering GSM Mobility as an IN Service  

Microsoft Academic Search

An architecture based on the integration of IN and GSM was presented as a possible path for the evolution of GSM to UMTS. From the standards point of view what is need is the absorption of MAP into INAP, resulting in a unified protocol. With a unified protocol the architecture presented here becomes viable. The decomposition of GSM services into

Sutha Siva; Laurie G. Cuthbert; Malcolm Read

1997-01-01

16

Secure Mobile Communication Using Low Bit-Rate Coding Method  

Microsoft Academic Search

Mobile telecommunications such as GSM are now well established globally and users rely heavily on convenient communications it provides. The level of security provided by GSM is superior to its predecessors and is more than adequate for majority of users. However some users in the area of government, defense or business require additional security over and above that provided by

Mohammed Wasif; Chirag R Sanghavi; Mamoon Elahi

2007-01-01

17

Randomness evaluation of stream cipher for secure mobile communication  

Microsoft Academic Search

Information Security over mobile communication networks is important for secure communication. In GSM mobile standard, A5\\/1 stream cipher is used to provide security over-the-air voice transmissions. It is strong encryption algorithm among the cryptographic algorithms used in GSM. However, it is cryptanalized by a number of attacks. Recent studies show that it has serious security weaknesses in its architecture. In

Musheer Ahmad; I. Izharuddin

2010-01-01

18

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

Microsoft Academic Search

BACKGROUND: There are about 1.6 billion GSM cellular phones in use throughout the world today. Numerous papers have reported various biological effects in humans exposed to electromagnetic fields emitted by mobile phones. The aim of the present study was to advance our understanding of potential adverse effects of the GSM mobile phones on the human hearing system. METHODS: Auditory Brainstem

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

2007-01-01

19

Enhanced privacy and authentication for the global system for mobile communications  

Microsoft Academic Search

The Global System for Mobile Communications (GSM) is widely recognized as the modern digital mobile network architecture. Increasing market demands point toward the relevancy of security-related issues in communications. The security requirements of mobile communications for the mobile users include: (1) the authentication of the mobile user and Visitor Location Register\\/Home Location Register; (2) the data confidentiality between mobile station

Chii?Hwa Lee; Min?Shiang Hwang; Wei?Pang Yang

1999-01-01

20

Stream ciphers for GSM networks  

Microsoft Academic Search

With the advance of wireless communications technology, mobile communications has become more convenient than ever. However, because of the openness of wireless communications, how to protect the privacy between communicating parties is becoming a very important issue. In this paper, we focus on the security of transferring voice message on the Global System for Mobile communication (GSM) networks. Stream cipher

Chi-Chun Lo; Yu-Jen Chen

2001-01-01

21

Stream Ciphers for GSM Networks  

Microsoft Academic Search

With the advance of wireless communications technology, mobile communications has become more convenient than ever. However, because of the openness of wireless communications, how to protect the privacy between communicating parties is becoming a very important issue. In this paper, we focus on the security of transferring voice messages on the Global System for Mobile communication (GSM) networks. Stream ciphers

Chi-chun Lo; Yu-jen Chen

2000-01-01

22

Law Enforcement, Forensics and Mobile Communications  

Microsoft Academic Search

By the end of 2004, the GSM Association reported that over 600 networks in more than 200 countries were serving more than 1.2 billion users (1). This extraordinary devel- opment of inexpensive and flexible mobile communications is also a source of new security challenges. This paper briefly lists the forensic challenges raised by handsets and overviews the handset analysis techniques

Vanessa Gratzer; David Naccache; David Znaty

2006-01-01

23

Low-latency secure mobile communications  

Microsoft Academic Search

On the one hand, the challenge of meeting various security requirements in the mobile and wireless environment is difficult, compared to the fixed and wired environment, because of the very nature of radio communications. On the other hand, wireless networks such as GSM, PCS and CDMA, which are predominantly circuit-switched voice networks, have been shielded from the vulnerabilities that exist

Vinod Kumar Choyi; Michel Barbeau

2005-01-01

24

An efficient authentication protocol for GSM networks  

Microsoft Academic Search

Today, the Global System for Mobile Communications (GSM) is widely recognised as the modern mobile network architecture. A large portion of GSM network traffic is a produced by constant signaling between mobile stations and the base stations. In order to reduce the network traffic, various signaling protocols have been proposed. In this paper, we propose a new authentication protocol, which

Min-Shiang Hwang; Yuan-Liang Tang; Cheng-Chi Lee

2000-01-01

25

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

PubMed Central

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

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

2003-01-01

26

Mutual Authentication for Mobile Communication Using Symmetric and Asymmetric Key Cryptography  

Microsoft Academic Search

\\u000a The Global System for mobile communication (GSM) is widely used for mobile communication where the mobile users can make and\\u000a receive call when they are moving independent of time, location, and network access. The wireless mobile systems are more\\u000a vulnerable to deceitful access and eaves dropping. Though the authentication process on GSM is giving a reasonable security\\u000a level but have

Tumpa Roy; Kamlesh Dutta

27

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

PubMed

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

Bachmor, T; Schöchlin, J; Bolz, A

2002-01-01

28

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

Microsoft Academic Search

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

Erdal Bekiroglu; Nihat Daldal

2005-01-01

29

Using DAB and GSM to Provide Interactive Multimedia Services to Portable and Mobile Terminals  

Microsoft Academic Search

The objective of the MEMO project is to design, integrate and operate applications which utilise interactive DAB services, i.e. combining the existing GSM mobile telecommunications network and the Digital Audio Broadcasting system. A first trial with this platform for mobile multimedia services was performed to demonstrate the results achieved after one year of work and cooperation of the European partners

Th. Lauterbach; M. Unbehaun; D. Angebaud; A. Bache; Th. Groult; R. P. Knott; P. Luff; G. Lebourhis; M. Bourdeau; Pierre Karlsson; Richard Rebhan; N. Sundström

1997-01-01

30

GSM Mobile Station Location Using Reference Stations and Artificial Neural Networks  

Microsoft Academic Search

In this paper we present a novel approach to the automatic GSM mobile station location. The approach is based on measurement of radio signal strengths from a number of the neighboring base stations (antennas) and estimation of the mobile station position using trained artificial neural network (ANN) models. First, we present an improved version of our previous positioning back propagation

Zoran Salcic

2001-01-01

31

Cortical Spreading Depression Elicited in Rat Brain after Exposure to Microwave from GSM Mobile Phone  

PubMed Central

The aim of the present work is to evaluate possibility of microwave emitted by cellular phone that can elicit cortical spreading depression (CSD) in rat brain and studying the characteristics of the evoked signals. (CSD) was elicited in cerebral cortex of anesthetized rats after exposure to microwave irradiation (935.2-960.2 MHz) from Global System for Mobile communications (GSM) mobile phone. With the microwave output of about 8.5 mW at the antenna - tissue surface (4mm in diameter), CSD was elicited after 50 sec irradiation from the beginning of a received signal to the mobile and after 35 sec irradiation from the beginning of a transmitted signal from the mobile. CSD was elicited in about 90% of experiments after irradiation by both types of signal exposure. The results have shown that slow potential change (SPC) has an amplitude of 4.5 ± 0.75 mV, duration of 1.5 ± 0.5 min and propagated speed of 3 mm/min on the average. The amplitude, duration and behaviour of SPC of the evoked spreading depression were found to be affected by irradiation time and the method of exposure.

Sallam, Samera M.

2006-01-01

32

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

NASA Astrophysics Data System (ADS)

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

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

2002-10-01

33

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.

Kwon, Myoung Soo; Vorobyev, Victor; Kannala, Sami; Laine, Matti; Rinne, Juha O; Toivonen, Tommi; Johansson, Jarkko; Teras, Mika; Lindholm, Harri; Alanko, Tommi; Hamalainen, Heikki

2011-01-01

34

The Global System for Mobile Communications Short Message Service  

Microsoft Academic Search

This tutorial presents an overview of the Global System for Mobile Communications Short Message Service from the viewpoint of implementing new telematic services. The SMS offers the users of GSM networks the ability to exchange alphanumeric messages up to the limit of 160 characters. The tutorial is motivated by an acute absence of research publications in this field. The information

C. Peersman; S. Cvetkovic; P. Griffiths; H. Spear

2000-01-01

35

Authentication of mobile users in personal communication system  

Microsoft Academic Search

The logical structure of a personal communication system (PCS) is divided into three layers: intelligent layer, transmission layer and access layer. The authentication of mobile users is realized in the intelligent layer. The database structure of the PCS, different from the existing systems such as GSM and IS-41 etc., is centralized. Therefore the authentication schemes used in existing systems cannot

Liu Jianwei; Wang Yumin

1996-01-01

36

Securing GSM voice through scrambling  

Microsoft Academic Search

GSM is the most widely used mobile communication system, which provides authenticity, confidentiality and integrity. The encryption however is for air interface only which means that it secures channel till the BTS. This air interface encryption has been cracked and other vulnerabilities like replay and man in the middle attacks have put all the personal and confidential communications at stake.

Iftikhar Ali Naeem; U. Rauf; S. F. Ahmad; S. Noor ul Hassan Shirazi

2010-01-01

37

Aircraft target measurements using A GSM-based passive radar  

Microsoft Academic Search

Passive radar using GSM cellular mobile communication signal had been demonstrated to be feasible for short-range moving target measurements. This paper presents some new results of aircraft measurements with enhanced performance. It is shown that the operation range of GSM-based passive radar can be substantially larger than the coverage of one normal base station cell that is allocated for mobile

Hongbo Sun; D. K. P. Tan; Yilong Lu

2008-01-01

38

Evolving perspectives of 4th generation mobile communication systems  

Microsoft Academic Search

The last decade of the 20th century has been witness to remarkable technological developments in the area of wireless communication technologies. Following the commercial deployment-and subsequent worldwide success-of 2nd generation mobile telecommunication systems, such as GSM, standardization bodies, industry partners and regulatory fora from around the globe joined forces in producing the standards for 3rd generation mobile telecommunication systems. In

Vangelis Gazis; Nikos Houssos; Anastasia Alnnistiotil; Lazaros Merakos

2002-01-01

39

Parsimonious Mobility Classification using GSM and WiFi Traces  

Microsoft Academic Search

Human mobility states, such as dwelling, walking or driving, are a valuable primary and meta data type for transportation studies, urban planning, health monitoring and epidemiology. Previous work focuses on fine-grained location-based mobility inference using global positioning system (GPS) data and external geo-indexes such as map information. GPS-based mobility characterization raises practical issues related to spotty coverage and battery drain,

Min Y. Mun; Deborah Estrin; Jeff Burke; Mark Hansen

2008-01-01

40

Comparison of bioactivity between GSM 900 MHz and DCS 1800 MHz mobile telephony radiation.  

PubMed

An increasing number of studies find that pulsed Radio Frequency (RF), electromagnetic radiation of both systems of digital mobile telephony, established and commonly used in Europe during the last years, GSM 900 MHz (Global System for Mobile telecommunications) and DCS 1800 MHz (Digital Cellular System), exert intense biological action on different organisms and cells (Hardell et al., 2006; Hyland, 2000; Kundi, 2004; Panagopoulos et al., 2004, 2007). The two types of cellular telephony radiation use different carrier frequencies and give different frequency spectra, but they usually also differ in intensity, as GSM 900 MHz antennas operate at about double the power output than the corresponding DCS 1800 MHz ones. In our present experiments, we used a model biological system, the reproductive capacity of Drosophila melanogaster, to compare the biological activity between the two systems of cellular mobile telephony radiation. Both types of radiation were found to decrease significantly and non thermally the insect's reproductive capacity, but GSM 900 MHz seems to be even more bioactive than DCS 1800 MHz. The difference seems to be dependent mostly on field intensity and less on carrier frequency. PMID:17454081

Panagopoulos, Dimitris J; Chavdoula, Evangelia D; Karabarbounis, Andreas; Margaritis, Lukas H

2007-01-01

41

Mobile satellite communications  

NASA Astrophysics Data System (ADS)

Mobile satellite communications is placed in a global perspective with attention focused on the various commercial systems currently available and those recently proposed. The technology behind the systems is discussed as well as military applications. Mobiles are also examined in terms of commercial competition and politics.

42

The CERN GSM monitoring system  

NASA Astrophysics Data System (ADS)

This paper presents the way CERN has approached the problem of monitoring its own GSM infrastructure, especially in the Large Hadron Collider (LHC) accelerator tunnel and other underground facilities, where a leaky feeder cable carries mobile phone signals, and where this technology is the only means for inter-personnel communications.

Ghabrous, Carlos

2010-04-01

43

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

NASA Astrophysics Data System (ADS)

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

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

2003-06-01

44

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

PubMed

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

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

2003-06-01

45

Assessment of RF radiation levels in the vicinity of 60 GSM mobile phone base stations in Iran.  

PubMed

Increasing development of mobile communication infrastructure while enhancing availability of the technology raises concerns among the public, who see more cell towers erected each day, about possible health effects of electromagnetic radiations. Thereon, a survey of radio-frequency radiation from 60 GSM base stations was carried out in Tehran, Iran at several places mostly located in major medical and educational centres. Measurements were performed at 15 locations near each base station site, i.e. 900 locations in total. Since there are other RF radiation sources such as broadcasting services whose carrier frequencies are <3 GHz, the whole band of 27 MHz to 3 GHz has been assessed for hazardous exposures as well. The results were compared with the relevant guideline of International Commission on Non-Ionising Radiation Protection and that of Iran, confirming radiation exposure levels being satisfactorily below defined limits and non-detrimental. PMID:23222504

Nayyeri, Vahid; Hashemi, Seyed Mohammad; Borna, Maryam; Jalilian, Hamid-Reza; Soleimani, Mohammad

2012-12-04

46

Effects of Mobile Communication  

Microsoft Academic Search

Before reviewing some of the key consequences of mobile communication technology, a brief discussion of how they fit within the media effects paradigm is in order. At the risk of oversimplification, we understand the media effects paradigm as a framework for understanding how mass media content influences attitudes and behavior of audience members. To be fair, it is important to

Scott W. Campbell

47

Telemedicine by mobile communication.  

PubMed

A concept of mobile telemedicine has been proposed to provide emergency care in a moving vehicle. The practicality of this technique was investigated through technical considerations required to realize mobile telemedicine. Some problems with this technique were identified, and measures to resolve the problems were devised. Then, theoretical analysis verified the feasibility of the proposed technique. Different multiplexing techniques for the multiple medical data transmission by mobile communication were investigated. An experimental system that can simultaneously transmit color images, an audio signal, three-channel ECGs, and blood pressure from a moving vehicle to a fixed station was developed. Experiments on the transmission of multichannel medical data from a moving ambulance, a navigating ship, and a flying aircraft were conducted. The results of these experiments verified the practical feasibility of the proposed technique. In the practical application of this technique, there may be some legal problems: for example, whether medical treatment through a communication medium would be legally acceptable or not, and whether the transmission of medical data violates the protection of personal privacy. However, considering the emergency nature of this technique and the significance of the results, both problems seem to be either legally or technically solvable. This application of mobile communication to telemedicine is not confined to merely a proposal to use new techniques. It can also bring about a methodological change in the concept of conventional telemedicine by changing it from static to dynamic, and by enlarging its scope from a local area to a global or cosmic area. It may also have an impact on conventional emergency medicine in that it will open up a new field of application that applies to moving vehicles. PMID:10429900

Shimizu, K

48

SAFETY DISTANCES IN MOBILE COMMUNICATIONS  

Microsoft Academic Search

For more than 60 years the electromagnetic spectrum has been used from most people solely for receiving broadcast and TV. Since several years individual mobile communication leads not only to a rise in spectrum use but also to a growing number of mobile base stations. The increasing number of these base stations in mobile communications causes considerations about possible adverse

MICHAEL BALDAUF; ALEXANDER HERSCHLEIN; WERNER SÖRGEL; WERNER WIESBECK

49

A novel interference matrix generation algorithm in GSM networks  

Microsoft Academic Search

Recently, the automatic frequency planning which is mainly based on interference matrix (IM) is widely used in global system for mobile communications (GSM) networks planning. Most IM generation algorithms are derived from the Mobile Measurement Reports (MMRs) received from mobile users. Since the number of bits used for MMRs is limited and the MMRs could only provide the power level

Yu Gao; Jingqun Song; Qixun Zhang; Yunfei Ma; Jinlong Wang V; Zhiyong Feng

2009-01-01

50

Advanced Communications Technology: Mobile Communications Requirements Report  

NASA Astrophysics Data System (ADS)

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

1998-05-01

51

The analysis of GSM-R redundant network and reliability models on high-speed railway  

Microsoft Academic Search

As a special digital mobile communication system designed for railway applications, GSM-R can provide voice and data services, as well as the basis of train control system on high-speed railways. Because of the rigid demands of train security, it is important to predict the network reliability of GSM-R network. Therefore, the redundant architecture of GSM-R network is widely used to

Ding Xun; Chen Xin; Jiang Wenyi

2010-01-01

52

End-to-end security for GSM users [speech coding method  

Microsoft Academic Search

Mobile telecommunications such as GSM are now well established globally and users rely heavily on the convenient communications it provides. The level of security provided by GSM is superior to its predecessors and is more than adequate for the majority of users. However, some users in the areas of government, defence or business require additional security over and above that

A. B. Rekha; B. Urnadevi; Y. Solanke; S. R. Kolli

2005-01-01

53

A novel speech-like symbol design for data transmission through GSM voice channel  

Microsoft Academic Search

This paper introduces a new approach to design speech-like (SL) symbols in order to transmit digital data through global system for mobile communications (GSM) voice channel. Using these symbols leads to design a GSM voice channel data modem to modulate and demodulate data on enhanced full rate voice codec. Designing a set of time-symbols is an offline procedure with the

Ali Shahbazi; Amir Hossein Rezaie; Abolghasem Sayadiyan; Saeed Mosayyebpour

2009-01-01

54

Efficient Design of Directive Patch Antennas in Mobile Communications Using Metamaterials  

NASA Astrophysics Data System (ADS)

An efficient approach for designing directive patch antennas using metamaterials is presented. Based on the left-handed-material (LHM) transmission line model, circuit elements L and C of the LHM equivalent circuit model are computed in terms of the prescribed desirable characteristics of directive patch antennas. Formulae to calculate the LHM design parameters from the circuit elements L and C are developed. Design examples for the GSM900 and GSM1800 frequency bands in mobile communications are performed to illustrate validation and efficiency of this design approach.

Wang, Rui; Yuan, Bo; Wang, Gaofeng; Yi, Fan

2007-08-01

55

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 Kämäräinen; Tero Heiskainen

56

GSM-based mobile tele-monitoring and management system for inter-cities public transportations  

Microsoft Academic Search

This paper presents a tele-monitoring and management system for inter-cities transportation vehicles such as taxis and buses. The system is based on a stand-alone single-board embedded system that is equipped with GPS and GSM modems that is installed in the vehicle. A personal computer based GSM-Server is installed at transportation's head-quarter. While the vehicle is on the move, its real-time

M. AL-Rousan; A. R. Al-Ali; K. Darwish

2004-01-01

57

Security Aspects of Mobile Communications  

Microsoft Academic Search

Security requirements and services of a mobile communication system differ, due to the radio communication between the user and the base station, extensively from those of a fixed network. There is no physical link in the form of a (fixed) telephone line between the user and the local exchange, which could serve to identify the user for routing and charging

Klaus Vedder

1991-01-01

58

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

2011-07-20

59

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 [1]. 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

2013-07-01

60

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

61

Competition in UK mobile communications  

Microsoft Academic Search

Since mobile communications began in the United Kingdom in 1985, with the licensing of two cellular networks, the number of subscribers has grown to eight million. Much of this growth has occurred in the past five years, which have also seen the emergence of new competition in the form of two PCN operators. The aim of this paper is to

Tommaso M Valletti; Martin Cave

1998-01-01

62

Trends in mobile satellite communication  

NASA Astrophysics Data System (ADS)

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

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

63

User mobility and channel holding time in mobile communications  

Microsoft Academic Search

An important parameter in the analysis of a communication system is the channel holding time of a call. In a mobile communication system, the cell channel holding time may be different than the call duration due to the mobility of the user. To study this impact of the user mobility, a new and general mobility model is presented and analyzed.

Harry Heffes; Kevin M. Ryan

1997-01-01

64

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.

65

Integration of intelligent network services into future GSM networks  

Microsoft Academic Search

This article introduces various difficulties and issues in the basic scenario of integrating intelligent networks (INs) and the Global System for Mobile Communications (GSM). As an example, implementation of Universal Personal Telecommunications (UPT) is considered. This article does not offer a comprehensive analysis, but rather a tutorial view. The separation of cellular networks and IN is not well suited to

M. Laitinen; J. Rantala

1995-01-01

66

Influence of GSM Microwaves on Fractal Structure of brain tumours  

Microsoft Academic Search

Fractal dimension of C-6 rat glioma tumours growing in microwave field generated by signal simulation of the Global System for Mobile communications (GSM) with frequency 960 MHz was found significantly enhanced as compared with field free tumours growing at different temperatures. The Mandelbrot answer to Richardson question: \\

M. Babincová; P. Sourivong; D. Leszczynska; P. Babinec

2003-01-01

67

Prospects of GSM technology for academic library services  

Microsoft Academic Search

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

Olayinka Catherine Fatoki

2005-01-01

68

Vehicle antennas for mobile satellite communications  

NASA Astrophysics Data System (ADS)

Research on and the state of the art of vehicle antennas for mobile satellite communications are reviewed. Particular attention is given to the concept of mobile satellite communication; system requirements for vehicle antennas; antenna systems for communications, navigation, and broadcasting; and future prospects of vehicle antennas. A monolithic microwave integrated circuit active phased array antenna is considered to be a key technology in the future mobile satellite communications.

Ohmori, Shingo

1991-10-01

69

Telemedicine using mobile satellite communication.  

PubMed

With a view to providing paramedical care within moving vehicles, a telemedicine technique using mobile satellite communication was proposed. With this technique, the diagnosis from a specialist and the emergency care under his/her instructions would be available on the spot without unnecessary delay. The characteristic problems of this technique were identified as: channel capacity, size of the system, reliability of vital sign transmission, real-time operation and electromagnetic interference. Measures against these problems were devised, and their effectiveness was analyzed. A data format was designed and an experimental system was developed. The system can simultaneously transmit a color image, an audio signal, 3 channels ECG and blood pressures from a mobile station to a ground station. It can transmit an audio signal and error control signals from a ground station to a mobile station in a full duplex mode. Fundamental transmission characteristics were measured in a fixed station. Finally, experiments of medical data transmission were conducted with a navigating ship and an aircraft flying an international route. The measured threshold values of C/N(o) to guarantee satisfactory data reception were well below the lower boundary of C/N(o) of the communication link. Consequently, the feasibility of this technique was verified. PMID:8070809

Murakami, H; Shimizu, K; Yamamoto, K; Mikami, T; Hoshimiya, N; Kondo, K

1994-05-01

70

Intelligent digital mobile communications network architecture  

Microsoft Academic Search

ital Mobile Communications Network which is based on the hierarchicalfunction arrangement. The network is layered to the intelligent layer and the transport layer. And each layer is also layered to several sub-hers. The network hasa capability which guarantees the mobility between plural mobile communications networks. The MSSP (multi-switch simultaneous paging) technique is applied in metropolitan areas io simultaneously page the

Akihisa NAKAJIMA; Masato EGUCHI; Takemi ARITA; Hideo TAKEDA

1990-01-01

71

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

72

Application of Mobile Router to Military Communications.  

National Technical Information Service (NTIS)

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-r...

D. H. Stewart W. D. Ivancic T. L. Bell B. A. Kachmar D. Shell K. Leung

2002-01-01

73

Antennas for mobile satellite communications  

NASA Astrophysics Data System (ADS)

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

1991-12-01

74

Hybrid Checkpoint Protocol for Supporting Mobile-to-Mobile Communication  

Microsoft Academic Search

Some information systems consist of mobile stations and fixed stations. Mission critical applications are required to execute fault-tolerance in these systems. However, the mobile stations support neither enough volume of storage, processing power nor battery capacity to provide reliable communication and computation. Thus, it is difficult for multiple mobile stations to synchronously take checkpoints. We propose a hybrid checkpointing protocol

Yoshinori Morita; Hiroaki Higaki

2001-01-01

75

Mobile IP LAN for ARL Mobile Communications/Networking Testbed.  

National Technical Information Service (NTIS)

This report describes the protocol and implementation of a Mobile IP (Internet protocol) LAN (local area network) for the LAN of the U.S. Army Research Laboratory (ARL) Mobile Communications/Networking Testbed. Mobile IP LAN protocol is developed to allow...

B. B. Luu

2001-01-01

76

Effect of global system for mobile communication microwave exposure on the genomic response of the rat brain  

Microsoft Academic Search

The acute effect of global system for mobile communication (GSM) microwave exposure on the genomic response of the central nervous system was studied in rats by measuring changes in the messenger RNAs of hsp70, the transcription factor genes c-fos and c-jun and the glial structural gene GFAP using in situ hybridization histochemistry. Protein products of transcription factors, stress proteins and

K Fritze; C Wiessner; N Kuster; C Sommer; P Gass; D. M Hermann; M Kiessling; K.-A Hossmann

1997-01-01

77

Visualization Management for Mobile Communication Network Resource  

Microsoft Academic Search

We combine database and graphics technology to accomplish a visualization management for mobile communication network resource. The system not only can edit and search base station, fiber optic cable and cording hole et al. resource information not also manage these information with visual manner. The resource using case about mobile communication network may be showed by picture. We utilize artificial

Ling Lu; Yufeng Wang; Bin Tang

2009-01-01

78

Land mobile communications satellite missions in Europe  

NASA Astrophysics Data System (ADS)

A market survey of the potential needs for land mobile communications in Europe in 1995 and 2005 was carried out. There is an exploding demand for land mobile communications in Europe. This demand justifies that every effort be made to develop as fast as possible a compatible pan-European terrestrial mobile system. The potential remaining needs, outside of the presently planned terrestrial mobile system, which can be served only by satellite, could exceed the capacity of a single medium size communications satellite in the available state of the art technology.

Deverdiere, R.

1986-09-01

79

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 čstablishment cause’ the BTS thinks to have recognized. A typical invalid channel access request or phantom RACH is characterized by an IMMEDIATE ASSIGNMENT procedure (assignment of an SDCCH or TCH) which is not followed by sending an ESTABLISH INDICATION from MS to BTS. In this paper a mathematical model for evaluation of the Power RACH Busy Threshold (RACHBT) in order to guaranty in advance determined outage probability on RACH is described and discussed as well. It focuses on Global System for Mobile Communications (GSM) however the obtained results can be generalized on remaining mobile technologies (ie WCDMA and LTE).

Kollár, Martin

2012-05-01

80

Mobile communication and the protection of children  

Microsoft Academic Search

Mobile phones and other smart connected devices have fundamentally changed contemporary life. Globally, we see unprecedented explosion of new generation mobile phones. More precisely, mobile communication is nowadays really pervasive in social life. For instance, children and young persons are emerging as active players in the wonderful world of ringing and being ringed. Many of them are attracted by intriguing

Rebecca Ong

2010-01-01

81

Architecture for Group Communication in Mobile Systems  

Microsoft Academic Search

In mobile computing systems the network configuration changes due to node mobility. The paper identifies the issues a group communication service has to take into account in order to handle node mobility. These include the need to identify the location of a node, and the ability to cope with inaccuracies in the determination of a group membership. A multi level

Ravi Prakash; Roberto Baldoni

1998-01-01

82

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

83

MIXes in Mobile Communication Systems: Location Management with Privacy  

Microsoft Academic Search

Summary. This paper introduces a new technique for location management in cellular networks. It avoids the recording of moving tracks of mobile subscribers. The described procedures are derived from the well known untraceable MIX network and the distributed storage of location information according to GSM networks.

Hannes Federrath; Anja Jerichow; Andreas Pfitzmann

1996-01-01

84

Simulation of Rayleigh faded mobile-to-mobile communication channels  

Microsoft Academic Search

In this paper, we present new methods for simulation of narrowband wireless channels for mobile-to-mobile communication. Since the statistical properties of these channels are different from typical cellular radio channels, new methods are needed for their simulation. We present a \\

Chirag S. Patel; S. L. Stuber; Thomas G. Pratt

2003-01-01

85

Cramer-Rao lower bound for jointly estimated channel taps and DC offset in a GSM\\/EDGE receiver  

Microsoft Academic Search

In the GSM\\/EDGE mobile communication system, if the receiving mobile station direct converts the RF signal to the baseband signal, DC offset will be generated and should be taken care of. Channel taps and DC offset can be estimated jointly based on the training sequence codes (TSCs). This paper presents the Cramer-Rao lower bound (CRLB) for jointly estimated channel taps

Hanguang Wu; Wen Xu

2005-01-01

86

Compact high performance microstrip dual-band bandstop filters for GSM mobile bands  

Microsoft Academic Search

In this paper a compact dual-band bandstop filter (DBBSF) that features two controllable stopbands at desired frequencies is presented. The open stubs of the standard PI network were replaced by Stepped-impedance resonators to realize the dual-stopband characteristics. Here a microstrip circuit is designed at operating frequency for mobile bands (0.9 GHz and 1.9 GHz). The 20 dB fractional band widths

Ajay Babu Guntupalli; S. Sanyal

2008-01-01

87

Signals in mobile communications: A review  

Microsoft Academic Search

The signals in mobile communications are reviewed both in terms of the physical scenario and as the basis of the transfer function of the mobile channel. The transfer function is arranged to demonstrate the inherent limitations (the irreducible bit error rate effect) resulting from using single port antennas, in both narrow- and wide-band systems. A new model for the average

RODNEY G. VAUGHAN

1986-01-01

88

Downlink beamforming for cellular mobile communications  

Microsoft Academic Search

A new technique for downlink transmission beamformer design in cellular mobile communications systems using an antenna array at the base station is presented. The method is based on estimation of an underlying spatial distribution associated with each source's spatial downlink channel. The algorithm is “blind” in the sense that it depends only on uplink spatial channel statistics, requiring no mobile-to-base

Jason Goldberg; Javier R. Fonollosa

1997-01-01

89

Downlink beamforming in cellular mobile communications  

Microsoft Academic Search

A technique for downlink transmission beamformer design in cellular mobile communications systems using an antenna array at the base station is presented. The method is based on estimation of an underlying spatial distribution associated with each source's spatial downlink channel. The algorithm is “blind” in the sense that it depends only on uplink spatial channel statistics, requiring no mobile-to-base station

J. R. Fonollosa; Jason Goldberg; G. Vazquez

1997-01-01

90

User Centric Privacy in Mobile Communication Scenarios  

Microsoft Academic Search

One common assumption when defining location privacy metrics is that one is dealing with attackers whose objective is to re-identify an individual out of an anonymized data set. However, today's communication scenarios are more diverse. For instance, there are several entities involved in mobile location sharing between individuals. Hence, in a communication relation with a service provider (e.g. SNS or

Klaus Rechert; Sven Wohlgemuth; Isao Echizen; Noboru Sonehara

2011-01-01

91

Presenting sponsored content on a mobile communication facility  

US Patent & Trademark Office Database

Improved capabilities for positioning content on a mobile communication facility, based in part on the likelihood of interaction with the content, are disclosed for mobile communications facilities, such as cell phones. These and other capabilities are employed to improve the likelihood of user interaction with content presented to a mobile communication facility, such as positioning content to appropriate or desirable mobile communication facilities.

Ramer; Jorey (Brighton, MA); Soroca; Adam (Cambridge, MA); Doughty; Dennis (Brookline, MA)

2010-07-06

92

Study on application of DSR protocol to mobile communication system  

Microsoft Academic Search

In general, the base station (BS) is fixed in the mobile communication system, however, which will be altered in some especial situations. To ensure the better communication, both BSs and mobile stations (MSs) of mobile communication network should be able to move in the network, namely entire mobility, which doesn't affect the communication of MSs. However, the route between BSs

Zhiyong Shi; Shenquan Zhu; Zhenyu Zhang

2005-01-01

93

HUMAN CONSTRAINTS FOR MOBILE COMMUNICATIONS  

Microsoft Academic Search

Mobile networks are proliferating currently in the world with a rather high pace. The number of mobile telecom subscribers has already exceeded one billion and the number will exceed two billions before the year 2010. The big investements needed in the telecom infrastructure raise the question, how much revenues can the operators and other players expect from the investments and

Pasi Tyrväinen; Jari Veijalainen

94

Metaheuristics for solving a real-world frequency assignment problem in GSM networks  

Microsoft Academic Search

The Frequency Assignment Problem (FAP) is one of the key issues in the design of GSM networks (Global System for Mobile communications), and will remain important in the foreseeable future. There are many versions of FAP, most of them benchmarking-like problems. We use a formulation of FAP, developed in published work, that focuses on aspects which are relevant for real-world

Francisco Luna; César Estébanez; Coromoto León; José M. Chaves-gonzález; Enrique Alba; Ricardo Aler; Carlos Segura; Miguel A. Vega-rodríguez; Antonio J. Nebro; José María Valls; Gara Miranda; Juan Antonio Gómez Pulido

2008-01-01

95

Mobile communication terminal and method therefore  

US Patent & Trademark Office Database

Control of setup of international calls in a mobile communication terminal is performed. The terminal is connected to a first mobile communication network that is operated by a first operator, and the method includes detecting a request to setup an international call, the request including a first symbol sequence including a country code and a subscriber identifier, selecting, in response to the detection, an operator prefix number, the operator prefix number specifying a second operator of a communication network that provides an international call setup service, creating a second symbol sequence including the operator prefix number, the country code and the subscriber identifier, and requesting a call setup with the subscriber via the second operator, the request including transmitting the second symbol sequence to the first mobile communication network.

2012-09-11

96

Short Message Service (SMS) Security Solution for Mobile Devices.  

National Technical Information Service (NTIS)

This thesis focuses on the security of Short Message Service (SMS) and the Global System for Mobile communication (GSM) network, and the use of encryption to protect SMS messages. A detailed study of the GSM network, the SMS protocol and various encryptio...

L. Yu

2006-01-01

97

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

98

Reliability consideration of a mobile communication system with network congestion  

Microsoft Academic Search

High quality traffic for networks is urgently needed for mobile communication systems. Mobile stations frequently become unavailable due to communication errors generated by network congestion. Traffic congestion in a network system may occur intermittently and continue for a length of time, sometimes causing communication errors. If congestions happens during communication, communication errors occur and the communication is rejected. This paper

Mitsutaka Kimura; Kazumi Yasui; Toshio Nakagawa; Naohiro Ishii

2006-01-01

99

Signal environment response of a generic mobile communication system  

Microsoft Academic Search

Mobile communication has been, and continues to be, an essential tactical requirement for many types of commercial and military operations involving cellular mobile communication systems, radio communication stations and mobile forces. Specific mobile unit requirements vary widely because of different needs and different traditional methods of satisfying such needs within the several branches of the customer. The system in object,

Servilio Sebastiani

1999-01-01

100

GLOBAL MOBILE SATELLITE COMMUNICATIONS: A REVIEW OF THREE CONTENDERS  

Microsoft Academic Search

The era of satellite-based mobile communications systems started with the first MARISAT satellite which was launched into a geostationary orbit over the Pacific Ocean in 1976 to provide communications between ships and shore stations. The combination of high cost and unacceptably large equipment has kept mobile satellite communications (MSC) systems from appealing to the wider market of personal mobile communications.

Gary M. Comparetto

1994-01-01

101

Novel implement for the mobile communication base transceiver station mechanism  

Microsoft Academic Search

A novel mobile communication base transceiver station architecture is considered. Moreover, we propose this new approach for constructing a dynamic mobile communication base station subsystem for all the wireless communication systems to reduce the cost of both fabrication and maintenance compared to existing approaches. This novel mobile communication base transceiver station system is employed to broadcast and receive radio signal

Ye Yan; Kwangsoo Kim; Jucheng Yang

2005-01-01

102

An ethnography of communication approach to mobile product testing  

Microsoft Academic Search

Product testing of mobile communication technology has typically employed the same research methodologies that were traditionally applied to stationary technology. An approach that does not primarily rely on physical location to study mobile communication technologies is thus needed. The stable component of mobile communication technology is not physical space but human communication. Therefore, a research model is developed based on

Linda M. Gallant

2006-01-01

103

Time reversal communication with a mobile source.  

PubMed

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

Song, H C

2013-10-01

104

Optimized Antennas for Mobile Communication Base Stations  

Microsoft Academic Search

This is a synopsis of work conducted to improve the electrical and mechanical performance of antennas used for mobile communication base stations. To accomplish this we first consider the propagation characteristics to determine the optimal antenna pattern. In addition, the antennas mechanical size and profile are minimized to improve its appearance and mounting ease. The end result of this work

J. R. Sanford; J.-F. Zurcher; S. Robert

1991-01-01

105

Internet Pajama: A Mobile Hugging Communication System  

Microsoft Academic Search

Internet Pajama is a novel wearable system aimed at pro- moting physical interaction in remote communication be- tween parent and child. This system enables parent and child to hug one another through a novel hugging interface device and a wearable, hug reproducing jacket connected through the Internet. The hugging device is a small, mobile doll with embedded pressure sensing circuit

James Keng; Soon Teh; Adrian David Cheok; Tim Merritt; Roshan Peiris

106

A voice scrambler for mobile communication  

Microsoft Academic Search

A new voice scrambling method for mobile communication is proposed. The principle is to invert the voice sample polarity selectively according to the scrambling code, smooth it with a low-pass filter, and feed it to the radio transmitter. To utilize the principle, the necessary techniques such as filtering, synchronizing and scrambling code design, are described. The whitened spectrum of the

SHIGERU ASAKAWA; FUMIO SUGIYAMA; M. Nakamura

1980-01-01

107

The evolution of global mobile communications  

NASA Astrophysics Data System (ADS)

A long term, global viewpoint is presented on the subject of communications access which may be the key to resolving many of the world's current requirements for developing a truly global, ubiquitous mobile/personal voice and data communications capability. The solutions are multi disciplinary, some using terrestrial techniques, some by satellite, but both using a variety of technologies and techniques. In the area of satellite communications, the focus is on inexpensive, efficient antennas, high gain spacecraft amplifiers and efficient power and bandwidth modulation techniques including high performance, low bit rate voice codecs. Terrestrially, many of the same technologies apply to cellular telephone systems. A key issue is the electromagnetic spectrum and its utilization efficiency, especially if the popularity of cellular telephones is repeated in the development of mobile satellite systems. Integration of diverse systems depends on formulating a framework that will allow systems to be interoperable by specifying logical interfaces among most or all evolving niche systems.

Spolsky, A. I.; Brasic, J. R.

108

First Satellite Mobile Communication Trials Using BLQS-CDMA.  

National Technical Information Service (NTIS)

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 Euro...

M. Luzdemateo S. Johns M. Dothey C. Vanhimbeeck I. Deman

1993-01-01

109

Secure Communication in Global Systems for Mobile Telecommunications  

Microsoft Academic Search

The digital cellular mobile telecommunication systems have become the trend of future personal communications services (PCS). In order to satisfy the high quality of services, security functions have been embedded into new mobile communication systems. In this paper, we investigate the security issues in the mobile communication systems and focus especially on the security functions of the Global Systems for

Shiuh-Pyng Shieh; Chern-Tang Lin; Jung-Tao Hsueh

110

Ray-Tracing for Mobile Communications  

Microsoft Academic Search

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

Sandra Knorzer; Thomas Fugen; Werner Wiesbeck

111

A Secure Protocol for Traffic Police Mobile Communication System  

Microsoft Academic Search

The advance of wireless networking, communication, and mobile technology is making a big impact to daily life. Mobile devices, such as cell phones, and PDAs are becoming more popular each day. The large number of mobile users along with the ubiquitous nature of mobile devices has created a huge market for mobile applications and is caused a strong demand on

Habibollah Arasteh Rad; Khairulmizam Samsudin; A. R. B. Ramli; M. B. Tehrani; M. A. Tavalai

2009-01-01

112

Inmarsat second generation satellites for mobile communications  

NASA Astrophysics Data System (ADS)

The second-generation satellites of Inmarsat (the International Maritime Satellite Organization) are in the final stage of integration and testing. The satellites will satisfy the needs originated by the rapid expansion of the system and will allow the introduction of new mobile communications services. The essentials of the spacecraft design and the types of services that will be provided using the new satellites are discussed, with particular consideration given to the characteristics of the communications transponder, its design and technology, the requirements and the design solutions, and the most significant communications parameters. Paralleled linearized traveling-wave amplifiers, L-band shaped global direct radiating array antennas, and surface-acoustic-wave channelization filters are being implemented in the system. Passive intermodulation product generation and multipaction are being recognized as design drivers.

Gambaruto, E.; Banks, D. K.; Krinsky, B.

113

Improving Communication for Mobile Devices in Disaster Response  

Microsoft Academic Search

During disaster response, networks can become overloaded and are susceptible to complete failure in the disaster area. This\\u000a disables mobile communication, hindering response efforts from mobile users. Mobile users make use of various heterogeneous\\u000a devices and require infrastructure to facilitate the communication of distributed information. Communication flow among mobile\\u000a users is disorganized as it is either too strong and hierarchical

Patricia Gómez Bello; Ignacio Aedo; Fausto Sainz; Paloma Díaz; Jennifer Munnelly; Siobhán Clarke

2007-01-01

114

A Review of Software Dened Radio: Mobile Channel Modelling and Simulation  

Microsoft Academic Search

TThe mobile communication system is characterized by dif- ferent standards, such as the AMPS, GSM, UMTS, GPRS, EDGE, and PDC, used in different parts of the world (2, 3, 8). This has prohibited mobile systems from oper- ating internationally. Apart from that, there is also a need to enable mobile communications systems to handle fast, secure, and error free data

Atli Lemma

115

New video applications on mobile communication devices  

NASA Astrophysics Data System (ADS)

The video applications on mobile communication devices have usually been designed for content creation, access, and playback. For instance, many recent mobile devices replicate the functionalities of portable video cameras and video recorders, and digital TV receivers. These are all demanding uses, but nothing new from the consumer point of view. However, many of the current devices have two cameras built in, one for capturing high resolution images, and the other for lower, typically VGA (640x480 pixels) resolution video telephony. We employ video to enable new applications and describe four actual solutions implemented on mobile communication devices. The first one is a real-time motion based user interface that can be used for browsing large images or documents such as maps on small screens. The motion information is extracted from the image sequence captured by the camera. The second solution is a real-time panorama builder, while the third one assembles document panoramas, both from individual video frames. The fourth solution is a real-time face and eye detector. It provides another type of foundation for motion based user interfaces as knowledge of presence and motion of a human faces in the view of the camera can be a powerful application enabler.

Silvén, Olli J.; Hannuksela, Jari; Bordallo-López, Miguel; Turtinen, Markus; Niskanen, Matti; Boutellier, Jani; Vehviläinen, Markku; Tico, Marius

2008-03-01

116

Mobile communication via satellite towards the year 2000  

NASA Astrophysics Data System (ADS)

Recently, mobile communication services are dramatically growing, and there is an ever increasing demand for these services. INMARSAT (International Maritime Satellite Organization) plays a very important role to establish mobile communication networks for ships and airplanes on the global basis. For personal mobile communication, INMARSAT is currently studying INMARSAT-P hand-held terminal in its Project 21. Several mobile satellite communication systems such as IRIDIUM and Globalstar systems are also proposed in order to realize personal communication services towards the 21st century. This paper presents a recent trend of mobile satellite communication systems mainly aiming at the realization of personal communication services. Activities of CCIR (International Radio Consultative Committee) and major results of WARC (World Administrative Radio Conference) '92 are also briefly introduced focusing on mobile satellite matters.

Hirata, Yasuo

117

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; André Deuker; Kai Rannenberg

118

Small Antennas for Mobile and Ultra-Wideband Communication  

Microsoft Academic Search

Mobile communication is an enormous growing market of communication and has a strong influence on the RF and microwave world. While UMTS is on the way of installation and going into business, new communication system technologies can be seen at the horizon of the communication world. One of this is UWB, the ultra wideband communication. This promising technology can become

D. Heberling; D. Manteuffel; M. Martínez-Vázquez; M. Geissler; O. Litschke

119

Model-based security analysis for mobile communications  

Microsoft Academic Search

Mobile communication systems are increasingly used in com- panies. In order to make these applications secure, the secu- rity analysis has to be an integral part of the system design and IT management process for such mobile communication systems. This work presents the experiences and results from the security analysis of a mobile system architecture at a large German telecommunications

Jan Jürjens; Joerg Schreck; Peter Bartmann

2008-01-01

120

MOBILITY, MEDIA, AND EVERYDAY LIFE - AN INTERDISZIPLINARY FRAMEWORK FOR COMMUNICATIONS  

Microsoft Academic Search

Communication technologies have become a natural and important part of people's everyday life. Since mobile media have the potential to accompany its user everywhere, they can be part of almost every situation. For that reason communication research should focus on the impact mobile media usage has on existing (media) situations or formulated as a research question: How do mobile media

Christine Dietmar; Georg F. Kircher; Isabel Schlote

121

Future Mobile Communication Networks: Challenges in the Design and Operation  

Microsoft Academic Search

In the past 20 years, mobile communications have evolved to the point where affordable broadband connectivity is widely available and plays a central role in today's information society. As mobile data rates are predicted to double annually in the next decade while the average revenue per user is likely to remain stagnate, the mobile communications industry is required to generate

Patrick Marsch; Bernhard Raaf; Agnieszka Szufarska; Preben Mogensen; Hao Guan; Michael Farber; Simone Redana; Klaus Pedersen; Troels Kolding

2012-01-01

122

Wide area mobile communication networks with multiple routing mode options  

Microsoft Academic Search

A wide area mobile communication network with multiple modes of transmission routing is described. This is achieved through the integration of multiple, independent wide area networks at both the fixed base station and the mobile device. Through this network, mobile communication devices have access to multiple rf transmission paths with varying characteristics of signal strength, coverage, data rates and cost.

David W. Best; Santanu Dutta; Dennis Sutherland

1995-01-01

123

Electromagnetic field pattern in the environment of GSM base stations.  

PubMed

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

Anio?czyk, H

1999-01-01

124

Mobile satellite communications systems - Toward global personal communications  

NASA Astrophysics Data System (ADS)

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 satellite communications systems are discussed. One approach emerging is the use of large satellites, with large antennas, operating at much higher carrier frequencies. A second approach is to use low-earth orbiting (LEO) satellites, in order to reduce the path loss. The LEO approach also results in much smaller propagation delays than those experienced with geostationary satellites.

Lodge, John H.

1991-11-01

125

Geographical dispersal of mobile communication networks  

NASA Astrophysics Data System (ADS)

In this paper, we analyze statistical properties of a communication network constructed from the records of a mobile phone company. The network consists of 2.5 million customers that have placed 810 million communications (phone calls and text messages) over a period of 6 months and for whom we have geographical home localization information. It is shown that the degree distribution in this network has a power-law degree distribution k and that the probability that two customers are connected by a link follows a gravity model, i.e. decreases as d, where d is the distance between the customers. We also consider the geographical extension of communication triangles and we show that communication triangles are not only composed of geographically adjacent nodes but that they may extend over large distances. This last property is not captured by the existing models of geographical networks and in a last section we propose a new model that reproduces the observed property. Our model, which is based on the migration and on the local adaptation of agents, is then studied analytically and the resulting predictions are confirmed by computer simulations.

Lambiotte, Renaud; Blondel, Vincent D.; de Kerchove, Cristobald; Huens, Etienne; Prieur, Christophe; Smoreda, Zbigniew; van Dooren, Paul

2008-09-01

126

Route Optimization for Intra Communication of a Nested Mobile Network  

Microsoft Academic Search

Network mobility, i.e. Internet access services for a moving network as a single unit brings about new challenging issues. A nested mobile network is a hierarchical form of multiple mobile networks. Nested mobile networks sufier from a pin- ball routing problem. This problem becomes more serious in the case of a communication between any two nodes in the same nested

Sungmin Baek; Jinkyu Yoo; Hosik Cho

127

Analysis and Enhancement of Authentication Algorithms in Mobile Networks  

Microsoft Academic Search

The present reserch investigated the existing authentication mechanisms for mobile communications and analyses these mechanisms as a step to propose enhancement to authentication. Specifically, the authentication signalling in GSM and UMTS mobile networks is minimized and consequently the bottleneck at authentication centre is avoided, by reducing the number of messages between mobile and authentication centre (i.e., reducing the procedures of

Sufian Yousef; Mohammad Al Nabhan

2006-01-01

128

Consensus in networks of mobile communicating agents  

NASA Astrophysics Data System (ADS)

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

Baronchelli, Andrea; Díaz-Guilera, Albert

2012-01-01

129

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

Microsoft Academic Search

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

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

1995-01-01

130

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

131

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…

Godoe, Helge

2006-01-01

132

A Greenhouse Remote Monitoring System Based on GSM  

Microsoft Academic Search

This paper designed a greenhouse remote monitoring system based on GSM. In this system, STC89C51RC is used as CPU and SIM900B is used as GSM\\/GPRS communication module. The temperature sensor, humidity sensor and CO2 concentration sensor constitute the detection module. The system can show environmental parameters by liquid crystal screen, realize data remote alarming through the GSM module. Users can

Hesong Huang; Hongning Bian; Shuchuan Zhu; Jibo Jin

2011-01-01

133

The Evolution of Base Station Antennas for Mobile Communications  

Microsoft Academic Search

This paper gives a general overview of the design of base station antennas for mobile communications. It explains underlying theoretical and practical implementation aspects in mobile communication networks of today and the future. In the first part the fundamental parameters of a base station antenna are discussed in the context of radio network design. In particular we discuss parameters such

C. Beckman; B. Lindmark

2007-01-01

134

Adaptive base station antennas for mobile communication systems  

Microsoft Academic Search

There has been a rapid increase in the number of mobile communication users, resulting in an equally rapid need for increased capacity in the networks. Extensive research and development work on advanced base station antennas for mobile communication is in progress at Ericsson. This includes both active and adaptive antenna systems. With the introduction of active antenna products, it is

Bjorn Johannisson

1998-01-01

135

Spatial traffic estimation and characterization for mobile communication network design  

Microsoft Academic Search

This paper presents a new method for the estimation and characterization of the expected teletraffic in mobile communication networks. The method considers the teletraffic from the network viewpoint. The traffic estimation is based on the geographic traffic model, which obeys the geographical and demographical factors for the demand for mobile communication services. For the spatial teletraffic characterization, a novel representation

Kurt Tutschku; Phuoc Tran-Gia

1998-01-01

136

Optical Fiber Feeder for Microcellular Mobile Communication Systems (H-015)  

Microsoft Academic Search

The authors investigate the feasibility of using an optical fiber feeder for microcellular mobile communication systems. The optical feeder enables compact and low-cost base stations, easy radio channel control, and flexible mobile communication systems. Basic transmission characteristics were investigated through optical transmission experiments. Using these results, it is estimated that the optical feeder can transmit 880 telephone channels for digital

Makoto Shibutani; Toshihito Kanai; Watani Domom; Katsumi Emura; Junji Namiki

1993-01-01

137

An HTS transceiver for third generation mobile communications  

Microsoft Academic Search

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

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

1999-01-01

138

Multimedia Environment for Mobiles (MEMO) - Interactive Multimedia Services to Portable and Mobile Terminals  

Microsoft Academic Search

The objective of the MEMO project is to design, integrate and operate applications which utilise interactive mobile Multimedia services by integrating two subsystems: a high-speed broadcasting system, and a low speed bi-directional communications system. This is realised by combining the existing GSM mobile telecommunications network and the Digital Audio Broadcasting system. After a first suc- cessful trial with this platform

Thomas Lauterbach; Matthias Unbehaun

1997-01-01

139

Enhancement of GSM Security Using Elliptic Curve Cryptography Algorithm  

Microsoft Academic Search

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. Security is a burning and intelligent issue. It will always remain relevant as it is important in all types of applications. GSM Security flaws have been identified several years ago. Some

Sukalyan Goswami; Subarna Laha; Satarupa Chakraborty; Ankana Dhar

2012-01-01

140

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

Microsoft Academic Search

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

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

141

Mobility management in current and future communications networks  

Microsoft Academic Search

This article describes current and proposed protocols for mobility management for public land mobile networks (PLMNs), Mobile IP, wireless ATM, and satellite networks. The integration of these networks is discussed in the context of the next evolutionary step of wireless communications networks. First, a review is provided of location management algorithms for PCS implemented over a PLMN. The latest protocol

L. F. Akyildiz; Janise McNair; Joseph Ho; H. Uzunalioglu; Wenye Wang

1998-01-01

142

Design of hybrid mobile communication networks for planetary exploration  

Microsoft Academic Search

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

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

2004-01-01

143

Land mobile communications and position fixing using satellites  

Microsoft Academic Search

Relay of land mobile communications directly between the vehicles and central stations using VHF repeaters on satellites in geosynchronous orbits is examined. Experiments demonstrated effective satellite-aided land mobile communications, analog and digital data relay, automatic real-time vehicle position fixing; specially designed satellite antenna, and a digital tone-code ranging responder which operates within the communications bandwidth. A commercial VHF base station

A. F. Brisken; R. E. Anderson; R. L. Frey; J. R. Lewis

1979-01-01

144

Connected Vehicle Insights. Trends in Machine-to-Machine Communications. An Overview of M2M Technology and Potential for the Transportation Sector. Technology Scan Series 2011-2012.  

National Technical Information Service (NTIS)

The Global System for Mobile Communications (GSM) Association predicts that there will be nearly 50 billion connected devices by 2025, nearly ten times the worlds predicted human population. ABI estimates that through 2012, Machine-to-Machine connected de...

S. H. Bayless

2013-01-01

145

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

Federal Register 2010, 2011, 2012, 2013

...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

146

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

Federal Register 2010, 2011, 2012, 2013

...Communications Devices, Including Mobile Phones and Components Thereof Notice...Communications Devices, Including Mobile Phones and Components Thereof, DN 2958...communications devices, including mobile phones and components thereof. The...

2013-05-31

147

The antenna system for the base station of mobile communication  

Microsoft Academic Search

The antenna system for a mobile communication base station in the meter (UHF) waveband is presented. Calculation of the antenna system is given and the effect of a mast on its radiation pattern rated. The designed antenna system allows the number of communication channels to be increased, increasing the communication range and improving its quality.

Aleksander V. Antonov; Yury M. Gerasimov

2003-01-01

148

Using Group Communication to Support Mobile Augmented Reality Applications  

Microsoft Academic Search

Augmented reality and group communication in wire- less ad-hoc networks form relatively new fields of research. When using group communication ordering and timeliness requirements are important. Moreover, when using wire- less ad-hoc networks, the possibility of network partition is a serious consideration. In this paper we explore these three issues in the context of using group communication to support mobile

Niels Reijers; Raymond Cunningham; René Meier; Barbara Hughes; Gregor Gaertner; Vinny Cahill

2002-01-01

149

A New Data Communication Protocol for Distributed Mobile Databases in Mobile Ad Hoc Networks  

Microsoft Academic Search

Three data communication methods can be provided in a MANET: data broadcast, data query, and peer-to-peer messaging. The formation of heterogeneous distributed mobile databases within a MANET that allows people to submit queries is becoming a reality. The goal of this paper is to integrate distributed mobile databases in MANETs and proposes a new data communication protocol that supports all

Afsaneh Rahbar; Mehran Mohsenzadeh; Amir Masoud Rahmani

2009-01-01

150

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

Microsoft Academic Search

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

Kyungsook Han

2002-01-01

151

GSM and GPRS Security  

Microsoft Academic Search

Analog cellular phones and networks were designed with minimal security which soon turned out to be insufficient. The GSM system provides solutions to a few impor- tant aspects of security: subscriber authentication, subscriber identity confidentiality and confidentiality of voice and data over the radio path. This paper gives an overview of the security features provided in a GSM PLMN and

Chengyuan Peng

152

Group Communications in Mobile Ad Hoc Networks  

Microsoft Academic Search

Efficient support of group communications is critical for most ad hoc network applications. However, manet group communications issues differ from those in wired environments because the wireless communications medium has variable and unpredictable characteristics, and the signal strength and propagation fluctuate with respect to time and environment. We provide an overview of group communications issues such as protocol design, state

Prasant Mohapatra; Chao Gui; Jian Li

2004-01-01

153

Integrated Mobile Network Systems for Ubiquitous Network Connectivity  

Microsoft Academic Search

With the advent of various mobile devices with diverse communication capabilities, the interoperability between these networks becomes imperative in order to pro- vide ubiquitous network connectivity with the highest throughput in mobile environments. We focus on the in- teroperability experiments between WiFi computer net- works and Cingular GSM\\/GPRS networks by utilizing these two networks as the transit networks between mo-

Michael Golightly; Lichun Bao

154

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

155

Evolving mobile communication practices of Irish teenagers  

Microsoft Academic Search

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

Anthony Cawley; Deirdre Hynes

2010-01-01

156

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

Microsoft Academic Search

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

Khaled M. F. Elsayed

1997-01-01

157

Solutions to the GSM Security Weaknesses  

Microsoft Academic Search

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

Mohsen Toorani; Ali Asghar Beheshti Shirazi

2008-01-01

158

Land Mobile Communications Satellite Missions (LAMOCOSAMIS) Task 2: Functional Requirements.  

National Technical Information Service (NTIS)

Existing, planned, and foreseeable land mobile communication services in Europe were reviewed. Functional characteristics of available and new services were studied. Assumptions on global architecture were made. Regulatory aspects were investigated. The s...

1985-01-01

159

Wireless infrared communications with edge position modulation for mobile devices  

Microsoft Academic Search

Driven by the Infrared Data Association, wireless infrared communication has become a very popular and widely used method for short-range data transmission between mobile devices like laptops, PDAs, and mobile phones. Especially in ad hoc connection applications, IrDA excels over radio-based solutions like Bluetooth or cable-based solutions like USB, due to the point-and-shoot characteristic of infrared communication. The quality and

T. Luftner; C. Kropl; R. Hagelauer; M. Huemer; R. Weigel; J. Hausner

2003-01-01

160

Integration of IP mobility and security for secure wireless communications  

Microsoft Academic Search

We present alternatives for the integration of Mobile Internet Protocol (Mobile IP) versions with IP Security (IPSec) to secure IP communications over the wireless link. We focus on network layer security and provisioning of security services while roaming to a foreign network, without having to trust the foreign network. Additionally, such a scheme does not require the correspondent host (CH)

Melbourne Barton; Derek Atkins; John Lee; Sanjai Narain; Deidra Ritcherson; Kemal E. Tepe; K. Daniel Wong

2002-01-01

161

Teleoperation of robots via the mobile communication networks  

Microsoft Academic Search

Internet-based teleoperation is becoming an important research field in robotics. Most of existing works employed the wired Internet or wireless local area network to transmit signals, which largely limited the movement of the robots. This paper presented a teleoperation project based upon mobile communication networks. Using mobile networks as the wireless transmission media free robots from space restriction, which is

Y. Y. Li; W. H. Fan; Y. H. Liu; X. P. Cai

2005-01-01

162

Why young consumers are not open to mobile marketing communication  

Microsoft Academic Search

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

Ian Grant

2007-01-01

163

Security analysis on a conference scheme for mobile communications  

Microsoft Academic Search

The conference key distribution scheme (CKDS) enables three or more parties to derive a common conference key to protect the conversation content in their conference. Designing a conference key distribution scheme for mobile communications is a difficult task because wireless networks are more susceptible to attacks and mobile devices usually obtain low power and limited computing capability. In this paper

Zhiguo Wan; Feng Bao; Robert Huijie DENG; Akkihebbal L. Ananda

2006-01-01

164

Comparison of upgrade techniques for mobile communication systems  

Microsoft Academic Search

For current mobile communication systems, two limitations exist which restrict their capacity and range of application. They can be characterised as an equipment limit which is determined by the maximum number of mobile stations that can be supported by a base station with given equipment, and an interference limit, which corresponds to a maximum number of carriers that can be

Michael Tangemann; Rupert Rheinschmitt

1994-01-01

165

Communicating on the Move: Mobile Ad-Hoc Networks.  

National Technical Information Service (NTIS)

Mobile Ad-Hoc Networks (MANETs) are wireless networks that continually re-organize themselves in response to their environment without the benefit of a pre-existing infrastructure. A MANET consists of a set of mobile participants who must communicate, col...

D. Nathans R. F. Dillingham

2007-01-01

166

Influence of new mobile tools on communication  

Microsoft Academic Search

With the advent of such new communication tools as cellular phones and the Internet, communication styles have diversified. This diversity has brought changes in community formation as well as such serious problems as network addiction and mutual distrust among users. The purpose of this study is to find clues to these problems produced by those new communication tools. Thus, we

Saori Murata; Fujio Toriumi; Kenichiro Ishii

167

Usability of a mobile, group communication prototype while rendezvousing  

Microsoft Academic Search

Mobile phones are increasingly being used collaboratively by social networks of users in spite of the fact that they are primarily designed to support single users and one-to-one communication. It is not well understood how services such as group SMS, SMS-based discussion lists and mobile instant messaging (IM) will be used by mobile groups in natural settings. Studying specific instances

Jeff Axup; Stephen Viller; Nicola J Bidwell

2005-01-01

168

Impact of Java Compressed Heap on Mobile\\/Wireless Communication  

Microsoft Academic Search

M-commerce has shown up as e-commerce in mo-bile and wireless communication, and now deals with on-line banking, stock trading, auctions, transactions, and mobile media. M-commerce applications are im-plemented with, for example, Java technology that sup-ports a client-and-server model and cross-platform mo-bile applications. They are attractive, but, need a large heap space, which may slow down the execution, lead to poor

Mayumi Kato; Chia-tien Dan Lo

2005-01-01

169

Surge current distributions in base station of mobile communication system  

Microsoft Academic Search

The paper presents selected results of on-site meas- urements of surge currents in a typical base station for mobile communication. The station consists of a communication tower and a small container with electronic equipment. The aim of these in- vestigations was to determine surge current distributions in con- ducting parts of the tower structure and the equipotential bonding configurations during

Renata Markowska

2003-01-01

170

An Underwater Sensor Network with Dual Communications, Sensing, and Mobility  

Microsoft Academic Search

This paper describes an underwater sensor network with dual communication and support for sensing and mobility. The nodes in the system are connected acoustically for broadcast communication using an acoustic modem we developed. The nodes are connected optically for higher speed point to point data transfers using an optical modem we developed. We describe the hardware details of the underwater

Carrick Detweiller; Iuliu Vasilescu; Daniela Rus

2007-01-01

171

Fuego: Experiences with Mobile Data Communication and Synchronization  

Microsoft Academic Search

In this paper, we present a summary of our experiences with mobile middleware research in the four-year Fuego Core project. The presented work focuses on data communication and synchronization. We present three middleware services for data communication and synchronization, namely the messaging, event, and file synchronizer services, and discuss their development and usage. We conclude with an integrated architecture of

Sasu Tarkoma; Jaakko Kangasharju; Tancred Lindholm; Kimmo E. E. Raatikainen

2006-01-01

172

Mobile Robot Communication Without the Drawbacks of Wireless Networking  

Microsoft Academic Search

The default solution for mobile robot communication is RF- networking, typically based on one of the IEEE 802.11 standards also known as WLAN technology. Radio communication frees the robots from umbilical cords. But it suers from several significant drawbacks, espe- cially limited bandwidth and range. The limitations of both aspects are in addition hard to predict as they are strongly

Andreas Birk; Cosmin Condea

2005-01-01

173

Robust and affordable mobile communications for emergency management  

Microsoft Academic Search

During any emergency reliable communications can be a matter of life-and-death. First-responder communications are widely seen as a critical emergency management issue identified by Hurricane Katrina in the USA, and the Indian Ocean Tsunami of 2004. In cooperation with national, regional, and local emergency management organisations a US research consortium has developed and demonstrated robust and affordable mobile communications systems

Michael Bowman; James H. Graham Jr.; James Gantt

2007-01-01

174

Application suggestions for mobile communication device based on location-based directory information  

US Patent & Trademark Office Database

A mobile communication device may include a mobile communication system configured to facilitate wireless mobile communications. A location sensing system may be configured to sense the location of the mobile communication device. A location-based points of interest application may be configured to locate points of interest within the vicinity of the mobile communication device based on the location of the mobile communication device. An application mapping application may be configured to locate user applications that are relevant to the points of interest within the vicinity of the mobile communication device. A user interface may be configured to present links to the user applications.

Moon; Hannah Youngsil (Boston, MA); Morley; Dorothy Beau (Wakefield, MA); Dobroth; Kathryn Mary (Jamaica Plain, MA)

2013-10-15

175

Nationwide mobile communication systems, volume 1, chapters 1 thru 4  

NASA Astrophysics Data System (ADS)

This thesis provides a basic understanding of nationwide terrestrial and satellite mobile communications and tracking technologies. Covered are systems currently available and in development. An analysis of user costs is performed for comparison. A more detailed satellite cost/benefit analysis for use by the trucking industry is also presented. Follow-on chapters contain discussions of the basic economic issues faces by satellite system operators and the regulatory history of mobile satellite services. Contained in the appendices are a more detailed discussion of mobile satellite systems and a layman's explanation of communication and navigation technologies. The conclusion presents comments on the possible future direction of these new mobile communication services and makes recommendations for trucking industry use.

Schworer, William Joseph, III

1990-06-01

176

Technical comparison of several global mobile satellite communications systems  

NASA Astrophysics Data System (ADS)

The era of satellite-based mobile satellite communications (MSC) systems started with the first MARISAT satellite which was launched into a geostationary orbit over the Pacific Ocean in 1976 to provide communications between ships and shore stations. The combination of high cost and unacceptably large equipment has kept the space-based MSC systems from appealing to the wider market of personal mobile communications. The progress made over the last ten years, however, in digital voice processing, satellite technology, and component miniaturization has resulted in the viability of satellite-based mobile satellite communications systems to meet the growing market in personal mobile communications using handsets similar to those currently in use with land-based cellular systems. Three of the more mature LEO/MEO satellite systems are addressed in this paper including GLOBALSTAR, Iridium, and Odyssey. The system architectures of each system are presented along with a description of the satellite and user handset designs and the multiaccess techniques employed. It will be shown that, although a number of similarities exist among the system addressed, each system is unique in a variety of significant design areas. It is concluded that the technical feasibility of satellite-based mobile satellite communications systems seems to be secure. It will be challenging, however, for the vendors to actually develop and deploy these systems in a cost effective, timely, and reliable way that meets a continually evolving set of requirements based upon a rapidly changing technology base.

Comparetto, Gary M.

177

Present situation and future development of multiple mobile robot communication technology  

Microsoft Academic Search

Mobile robot communication technology is one of the important research domains of multiple mobile robot cooperation technologies. It includes communication of the master to the slavers in which wireless mode is widely adopted and the slavers to slavers. This paper discusses the present situation of the key technologies in multiple mobile robot communication, include communication, topology structure, communication model and

Zhou Yun; Zhang Yong-qiang; Zhou Wan-zhen

2010-01-01

178

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

NASA Astrophysics Data System (ADS)

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

1985-12-01

179

Modeling and Optimization of Zone-Based Registration for Mobile Communication Network  

Microsoft Academic Search

An efficient mobility management for mobile stations plays an important role in mobile communication networks. Two basic operations of mobility management are location registration and paging. A zone-based registration (ZBR) is implemented in most of the mobile communication networks and we consider the mobility management scheme that combines a zone-based registration and a selective paging (SP). We propose a new

JANG-HYUN BAEK; KYUNG-HEE KIM; Douglas C. Sicker

2007-01-01

180

FOREST OPERATIONS MANAGEMENT: TOWARDS MOBILE COMMUNICATION  

Microsoft Academic Search

Large worldwide operating forest industry companies use modern information and communication technology (ICT) in forest operations management nowadays. Many of the smaller companies are introducing these systems as well. The necessary condition for the use of these systems is a well developed communication infrastructure of the country. Similar systems are applied elsewhere, too, but they may not be as sophisticated

Esko Mikkonen

181

Electromagnetic compatibility problems in mobile communication systems  

Microsoft Academic Search

Summary form only given, as follows. Personal wireless communication services are considered as a subset technology of the information age. They have gained importance and visibility over the 1990s, and future technological advancements in this field will be unprecedented. As the thrust into wireless personal communication continues with more advanced and compact technologies the risks increase of \\

D. C. Pande

1999-01-01

182

Mobile communications and the federal telecommunications system  

Microsoft Academic Search

The first major radio program of the Federal Telecommunications System has been the installation of an extended-coverage VHF Mobile Telephone System for evaluation of the common-user concept of reducing the number of frequencies required by several users by time-sharing. Subscribers are provided three-channel full-duplex dial-up service, with such features as direct dialing of any other mobile, as well as any

R. B. Conrad

1959-01-01

183

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

184

Communicating Mobile Nano-Machines and Their Computational Power  

NASA Astrophysics Data System (ADS)

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

Wiedermann, Ji?í; Petr?, Lukáš

185

Mobile satellite communications in the 1990's  

NASA Astrophysics Data System (ADS)

The evolution of Inmarsat global services from a single market and single service of the 1980's to all of the key mobile markets and a wide range of new terminals and services in the 1990's is described. An overview of existing mobile satellite services, as well as new services under implementation for introduction in the near and longer term, including a handheld satellite phone (Inmarsat-P), is provided. The initiative taken by Inmarsat in the integration of its global mobile satellite services with global navigation capability derived from GPS (Global Positioning System) and the GLONASS (Russian GPS) navigation satellite systems and the provision of an international civil overlay for GPS/GLONASS integrity and augmentation is highlighted. To complete the overview of the development of mobile satellite services in the 1990's, the known national and regional mobile satellite system plans and the various recent proposals for both orbiting and geostationary satellite systems for proving handheld satellite phone and/or data messaging services are described.

Singh, Jai

1992-07-01

186

Novel End-to-End Voice Encryption Method in GSM System  

Microsoft Academic Search

For the GSM security mechanism cannot assure end-to-end secure communications, this paper presents a novel voice encryption method based on current voice channel, which overcomes data channel's shortages and solves the problem of voice encryption penetrating the RPE-LTP vocoder. The proposed method realizes the end-to-end secure communications in the GSM system with short time delay, good compatibility to all GSM

H. F. Qi; X. H. Yang; R. Jiang; B. Liang; S. J. Zhou

2008-01-01

187

Family guard against theft and alarm system based on GSM Modem  

Microsoft Academic Search

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

Zhou Yu; Zhisong Hou; Gaoli Zhao; Xiangang Zuo

2011-01-01

188

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

Microsoft Academic Search

Today, mobile communications play a central role in the voice\\/data network arena. With the deployment of 3G just around the corner, new directions are already being researched. In this paper we address the evolution of mobile communications, from its first generation, 1G, to the latest 3G, and give a glimpse of the foreseeable future of Beyond 3G (B3G). In the

Vasco Pereira; Tiago Sousa; Paulo Mendes; Edmundo Monteiro

189

Multicast Algorithms for Mobile Satellite Communication Networks.  

National Technical Information Service (NTIS)

With the rise of mobile computing and an increasing need for ubiquitous high speed data connections, Internet-in-the-sky solutions are becoming increasingly viable. To reduce the network overhead of one-to-many transmissions, the multicast protocol has be...

R. W. Thomas

2001-01-01

190

Secure Conversation Using Cryptographic Algorithms in 3G Mobile Communication  

Microsoft Academic Search

\\u000a Cryptographic algorithms used by Mobile Subscribers to protect the privacy of their cellular voice and data communication.\\u000a Mobile network is the shared media. When media are shared, privacy and authentication are lost unless some method is established\\u000a to regain it. Ciphering provides the mean to regain control over privacy and authentication. A5\\/x are the encryption algorithms\\u000a used in order to

Alpesh R. Sankaliya; V. Mishra; Abhilash Mandloi

191

On smart base-station antennas for mobile communications  

Microsoft Academic Search

Conventional base-station sector antennas for mobile communications are relatively inexpensive, but do not give an effective protection against interference. An alternative approach is to use directional adaptive phased arrays, which could additionally provide an increased protection against multipath fading and an ability to match antenna radiation to local conditions. For a narrow-band mobile system, we believe that a DSP-based phased

T. B. Vu; G. Jonas

1996-01-01

192

Downlink beamforming for spatially distributed sources in cellular mobile communications  

Microsoft Academic Search

This paper presents a new technique for downlink transmission beamformer design in cellular mobile communication systems using antenna arrays at the base station. The method is based on estimation of an underlying spatial distribution associated with each source’s spatial downlink channel. The algorithm is ‘blind’ in the sense that it depends only on uplink spatial channel statistics, requiring no mobile-to-base

J. M. Goldberg; J. R. Fonollosa

1998-01-01

193

Multihop Mobile Communications System Adopting Fixed Relay Stations and its Time Slot Allocation Schemes  

Microsoft Academic Search

In this paper, we present a multihop mobile communications system utilizing fixed relay stations to enhance the coverage of the service area. A multihop mobile communications system was originally proposed as a system in which only mobile stations relay communication between other mobile stations and a base station to solve the problem of poor coverage expected in a future cellular

Takeo Ohseki; Naoki Fuke; Hiroyasu Ishikawa; Yoshio Takeuchi

2006-01-01

194

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

195

UMTS universal mobile telecommunications system: development of standards for the third generation  

Microsoft Academic Search

The standards for the UMTS Universal Mobile Telecommunications System are being developed by the ETSI (European Telecommunications Standardisation Institute). The UMTS is a set of standards aimed at the global market. It will be a real third generation Global System for Mobile Communications adding new features and introducing relevant technological innovations while evolving from both GSM and ISDN networks. The

A. Samukic

1998-01-01

196

Integrating Communication, Computer Access, Environmental Control & Mobility.  

ERIC Educational Resources Information Center

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

Romich, Barry A.; Vagnini, Carol B.

197

Implementation of a land mobile terminal for satellite data communication  

NASA Astrophysics Data System (ADS)

A prototype for a Land Mobile Terminal (LMT) to perform in-field experimentation and validation activities on the mobile - satellite - shore station link, and to confirm the validity of the proposed LMT implementation was developed for PRODAT. The PRODAT LMT will be a two way system for demonstrating a data only communication at low data rate between land mobile users and a network managing system using the MARECS-A satellite and future dedicated satellites. The terminal consists of the antenna, plus an RF box, below roof equipment, and user interface.

Valsasina, G. B.

1986-09-01

198

Design of mobile shelters for communication purposes  

NASA Astrophysics Data System (ADS)

A general design for a future generation of shelters, to be used as mobile work places, is presented. Design criteria involve ergonomics, functional suitability, and air conditioning. Electronics, power supply, and personnel get their own compartments. Work space is provided for two people with room for two more. Center of mass and cable connections are considered. Air conditioning requirements are calculated with a computer program. The result is an integrated design, applicable to shelters for several purposes.

Lotens, W. A.; Leebeek, H. J.

1982-03-01

199

Beijing Calling... Mobile Communication in Contemporary China  

Microsoft Academic Search

Subsequently, with the recent wave of industrialization, China has become the “factory” of the globalized world. The modernization\\u000a of this country, however, is not confined to the provision of production at a low added value: It also entails technological\\u000a appropriation and innovation. In particular, China represents the biggest world market for mobile phones and will soon dominate\\u000a the Internet market.

Leopoldina Fortunati; Anna Maria Manganelli; Pui-lam Law; Shanhua Yang

2008-01-01

200

Unequal Importance Image Communication over Heterogeneous Networks  

Microsoft Academic Search

An unequal importance communication approach, for reliable and real-time image communication over heterogeneous networks and its applications in mobile communication systems is presented. Here, an image is partitioned into different layers of importance: base layer and enhancement layers. The base layer description, which can be strongly protected, is transmitted through a robust, low-bandwidth channel, supporting delay- sensitive applications (e.g. GSM

Mehdi Malboubi; Ahmad Bahai; Mustafa Ergen; Pravin Varaiya; Jean C. Walrand

2007-01-01

201

Open Innovation in Mobile and Convergent Communications  

Microsoft Academic Search

The concept of open innovation seems to be very well suited to information and communication technologies. In the first place,\\u000a as in any other field, the complexity of the new technology makes it necessary for companies to use ideas, processes and inventions\\u000a from other players. As in any other field, we need the collaboration of the university, of SMEs, of

José Jiménez

2008-01-01

202

Huggy Pajama: a mobile parent and child hugging communication system  

Microsoft Academic Search

Huggy Pajama is a novel wearable system aimed at promoting physical interaction in remote communication between parent and child. This system enables parents and children to hug one another through a novel hugging interface device and a wearable, hug reproducing pajama connected through the Internet. The hugging device is a small, mobile doll with an embedded pressure sensing circuit that

James Keng Soon Teh; Adrian David Cheok; Roshan Lalintha Peiris; Yongsoon Choi; Vuong Thuong; Sha Lai

2008-01-01

203

Neurological effects of microwave exposure related to mobile communication  

Microsoft Academic Search

Due to the wide and growing use of mobile communication, there is increasing concern about the interactions of electromagnetic radiation with the human organism, and, in particular, with the brain. In the present report, experimental studies on putative electrophysiological, biochemical and morphological effects of continuous or pulsed microwave radiation are briefly reviewed. Such effects have been described in vitro and

Dirk Matthias Hermann; Konstantin-Alexander Hossmann

1997-01-01

204

Superconducting air interface for mobile communications base stations  

Microsoft Academic Search

An overview of the receive side of the air interface to a mobile communications base station using superconducting components is given. The system is designed for a DCS 1800 base station. The superconducting receive filter and duplexer are described together with comments on the encapsulation and cooler

M. J. Lancaster; J.-S. Hong; D. Jedamzik; R. B. Greed

1998-01-01

205

Base-Station Antenna Arrays in Mobile Communications  

Microsoft Academic Search

This paper describes the utilization of antenna arrays at the basestations of mobile communication systems. Multiple antennas can providea processing gain to increase the base station range and improvecoverage. Also, by exploiting the angular selectivity of an antenna arrayat the base stations of a wireless system, users may be spatiallymultiplexed to increase system capacity. We address several aspectsof the reception

Björn Ottersten; Per Zetterberg

1995-01-01

206

Design of triplexer combiners for base stations of mobile communications  

Microsoft Academic Search

This work presents a design technique for a class of combining networks used in base stations for mobile communications; the considered network is a triplexer composed by three high selectivity filters presenting arbitrary transmission zeros (both complex and pure imaginary), which are connected at the input port through a suitable 4-port junction. A technique for the design of this combining

Giuseppe Macchiarella; Stefano Tamiazzo

2010-01-01

207

On antennas of base-station for mobile communications  

Microsoft Academic Search

With retrospect to the development trace of antenna of base-station for mobile communications, some inappropriate concepts are indicated for discrimination or correction, including the pattern synthesis, feeding of multi-penal antenna, polarization and anti-fading. Their actualized techniques are briefly pointed out.

Wen-Xun Zhang

2009-01-01

208

Design and realization of base station antenna for mobile communication  

Microsoft Academic Search

In this paper, we design and realize a type of dual-polarization base station antenna on the basis of an L-strip patch antenna for mobile communication. To improve the polarization isolation of the antenna, a novel scheme is proposed which uses the two adjacent units to counteract the coupled components. In order to allow the antenna's vertical pattern to accord with

Wang Chunhua; Lin Deyun; Shi Changsheng

2002-01-01

209

The SDMA\\/TDD base station for PHS mobile communication  

Microsoft Academic Search

Space division multiple access (SDMA) is a multiple access scheme for mobile communications that improves system capacity. We developed the SDMA base station (BS) and carried out several tests. We describe the configuration of the SDMA BS and the results of the tests. The result of the indoor measurement indicates that the SDMA BS has sufficient interference suppression performance. The

Yoshiharu Doi; T. Ito; Jun Kitakado; Takeo Miyata; Seigo Nakao; Takeo Ohgane; Y. Ogawa

2002-01-01

210

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

211

Application of radio-over-fiber (ROF) in mobile communication  

Microsoft Academic Search

Future generation of mobile communication system must be capable of serving high quality and broadband services even in highly dense populated area. The radio-over-fibre is one of the promising systems which can be used along the emerging wireless technologies such as smart antenna or multiple input multiple output (MIMO) systems to meet these requirements. In this paper, the role of

Reza Abdolee; Razali Ngah; Vida Vakilian; Tharek A. Rahman

2007-01-01

212

A low-power wireless mobile communications system  

Microsoft Academic Search

The paper describes a wireless mobile communication system which employs a high gain electronically steered array antenna connected to a radio receiver at a base station. By using a steerable, narrow beamwidth, high gain antenna pattern, the receiver can detect much weaker signals than receivers connected to conventional fixed pattern antennas. Since this system can detect weaker signals, either the

Steven A. Harbin; B. Keith Rainer

1994-01-01

213

On a Model for Radio Propagation in Land Mobile Communication  

Microsoft Academic Search

This article describes a study on a model for radio propagation in a land mobile communication (LMC), which differs from models based on the well-known theory for tropospheric propagation. The new propagation model has been constructed from a phenomenological paint of view for an LMC in an area where artificial or natural obstacles are present. This new model is based

Toshihiro Terada

1995-01-01

214

Risk perception of mobile communication: a mental models approach  

Microsoft Academic Search

Some lay people confronted with a new base station project fear serious health consequences from the high?frequency radiation, while experts consider exposure under the current international standards as unproblematic. These conflictive estimations may be attributed to the different mental models of lay people and experts. Less is known about lay people’s knowledge in regard to mobile communication and their intuitive

Michael Siegrist

2010-01-01

215

Distributed real-equipment testing for the mobile communications services  

Microsoft Academic Search

The test activities performed during the life cycle of the telecommunication service development ensure the service quality and stability so necessary to achieve the maximum availability and reliability. The paper presents authors' contribution to remote and distributed testing for mobile communications services based on cloud computing assets and paradigms. The access solutions to the test methods were implemented for the

Virgil Cazacu; Laura Iuga; Titus Balan; Florin Sandu

2011-01-01

216

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

217

A Constructivist Simulation-Based Methodology for Teaching Mobile Communications  

Microsoft Academic Search

A constructivist simulation-based methodology for teaching mobile communication systems in the electrical engineering curriculum is reported. In this methodology, senior undergraduate students develop simulators under the guidance of an advisor, and the simulators are later used by other students to learn these particular technologies. Evaluations based on students' results and opinions demonstrate the effectiveness of the methodology for improving the

Gustavo Vejarano; Fabio G. Guerrero

2008-01-01

218

Generic Conversion of Communication Media for Supporting Personal Mobility  

Microsoft Academic Search

The Intelligent Personal Communication Support System is intro- duced as an application for multiple media conversion tools, embedded in a con- text of personal mobility, service personalization and service interoperability support. After discussing models for conversion in theory, the current conversion technology is evaluated. The necessity of an integrated framework of flexible converters and a generic converter model are derived

Tom Pfeifer; Radu Popescu-zeletin

1996-01-01

219

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

220

Enabling rich mobile applications: joint computation and communication scheduling  

Microsoft Academic Search

With the universal adoption of mobile communication devices for many common computing applications like email and web access, there is a growing demand to use these devices for richer applications that require high computing power. This paper looks at a way of enabling thin wireless clients to support powerful applications by using processing and networking infrastructure that are available in

Shoubhik Mukhopadhyay; Curt Schurgers; Sujit Dey

2009-01-01

221

Integrated Wireless Communication Protocol for Ad-Hoc Mobile Networks  

Microsoft Academic Search

Wireless ad-hoc networks have recently emerged as a relevant research topic. The management of ad hoc networks raises many interesting problems, and adding the mobility to the network's components in- creases the number of these challenges. The ap- proaches to the real-time communication among the network's units should guarantee robustness, flexi- bility and scalability, while meeting the timing con- straints

Tullio Facchinetti; Giorgio Buttazzo

2004-01-01

222

Mobility-based communication in wireless sensor networks  

Microsoft Academic Search

Wireless sensor networks are proposed to deliver in situ observations at low cost over long periods of time. Among numerous challenges faced while designing WSNs and protocols, maintaining connectivity and maximizing the network lifetime stand out as critical considerations. Mobile platforms equipped with communication devices can be leveraged to overcome these two problems. In this article existing proposals that use

Eylem Ekici; Yaoyao Gu; Doruk Bozdag

2006-01-01

223

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

224

Mobile peer-to-peer frequency-hopping communications  

Microsoft Academic Search

The potential performance of mobile peer-to-peer frequency-hopping communication systems in multiple-access networks is studied. Through analysis and simulation, the effects of Rayleigh fading, shadowing, spectral splatter, the number of frequency channels, spatial diversity, and thermal noise are examined

Don Torrieri

1998-01-01

225

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, Márton; Kertész, János; Kaski, Kimmo

2012-01-01

226

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

Federal Register 2010, 2011, 2012, 2013

...Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof; Correction to Notice of Receipt...Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof, DN 2958; the Commission...

2013-06-06

227

Resource Allocation Scheme to Minimize Communication Cost in Mobile Ad Hoc Computational Grids  

Microsoft Academic Search

Recent advancements in mobile computing and communication technologies has given rise to development of mobile ad hoc computational grids. The mobile ad hoc computational grids provide a software infrastructure to share computing resources in mobile ad hoc environments. The adaptation of computational grids in mobile ad hoc environments is not straightforward, and presents many research challenges due to node mobility

Sayed Chhattan Shah; Myong-Soon Park

2010-01-01

228

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

Microsoft Academic Search

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

Shoichiro Sakata; Tadao Saito; Hiroshi Inose

1984-01-01

229

A new mobile communication system using autonomous radio link control with decentralized base stations  

Microsoft Academic Search

A highly advanced and diversified society has been making a significant impact on the increase in the demand for mobile communications. This paper proposes a new concept of a mobile communication system based on the deployment of decentralized autonomous radio link control with decentralized base stations (DCM system: Decentralized Control architecture Mobile communication system). After presenting the service conditions and

T. Hattori; Akio SASAKI; Kohji MOMMA

1987-01-01

230

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

Microsoft Academic Search

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

Raine Kelkka; Tommi Kallonen; Jouni Ikonen

2009-01-01

231

Mobile Lorm Glove: introducing a communication device for deaf-blind people  

Microsoft Academic Search

Marginalized communities like deaf-blind people are excluded from several forms of communication. This paper introduces a novel system of interaction to support deafblind people's communication and therefore enhance their independence. We introduce the Mobile Lorm Glove: a mobile communication and translation device for the deafblind. The glove translates the hand-touch alphabet Lorm, a common form of communication used by people

Ulrike Gollner; Tom Bieling; Gesche Joost

2012-01-01

232

Energy conservation in access protocols for mobile computing and communication  

Microsoft Academic Search

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

I. Chlamtac; C. Petrioli; J. Redi

1998-01-01

233

On the base stations antenna system design for mobile communications  

Microsoft Academic Search

The design of a base station antenna for mobile communications is presented. The orthogonal method (OM) is applied under constraints\\u000a on nulls of the radiation pattern. In the synthesis process the mutual coupling between the elements of the antenna array\\u000a could be taken into account. Beam tilting and direction of arrival are also considered. The whole design is completed by

George S. Miaris; Eleftheria Siachalou; Theodoros Samaras; Sotirios K. Goudos; Elias Vafiadis; Stavros Panas

2006-01-01

234

SAW-based IF Processors for mobile communications satellites  

NASA Astrophysics Data System (ADS)

Future generation mobile communications satellite must operate with very limited spectrum allocations and hence require sophisticated on-board processing to provide efficient spectrum management. This paper discusses the use of a complex Surface Acoustic Wave based, IF Processor which will perform the signal processing functions on Inmarsat 3. Comprehensive experimental performance data, obtained from a COM DEV internally funded program has clearly demonstrated the design and implementation to be optimum for the Inmarsat 3 program.

Kovac, Robert; Lee, Mike; Miller, Nigel; Peach, Robert; Swarup, Arvind; van Osch, Brent; Veenstra, Arnold

1991-10-01

235

Land mobile communications and position fixing using satellites  

Microsoft Academic Search

In a recent series of experiments, the General Electric Corporate Research and Development Center demonstrated effective satellite-aided land mobile communications, analog and digital data relay, and automatic real-time vehicle position fixing. In one sequence of tests a station wagon was equipped with a specially designed antenna, a slightly modified commercial VHF transceiver, and a digital tone-code ranging responder that operated

AXEL F. BRISKEN; ROY E. ANDERSON; RICHARD L. FREY; JAMES R. LEWIS

1979-01-01

236

GPCA Method for Fraud Detection in Mobile Communication Networks  

Microsoft Academic Search

To improve the fraud detection accuracy by SVM(support vector machine), a feature extraction method named GPCA based on IG (information gain) and PCA (principal component analysis) is proposed. It analyzes the data on CDR(call detail record), customer information,paying and arrear information etc in mobile communication networks , and then the data can be used by the classifier SVM to build

WANG Da-zhen

2006-01-01

237

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

Microsoft Academic Search

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

Jack Linchuan Qiu

2010-01-01

238

A Survey of Web Architectures for Wireless Communication Environments  

Microsoft Academic Search

The WWW is currently considered as the most promising and rapidly evolving soft- ware platform for the deployment of applications in wide area networks (telematics) as well as enterprise intranets. Another technology that proliferates rapidly in such environments is wire- less communication networks (e.g., GSM, wireless LANs). The combination - merging of the two technologies (i.e., mobile computing based on

Stathes Hadjiefthymiades; Lazaros F. Merakos

1999-01-01

239

System, method and article of manufacture for a mobile communication network utilizing a distributed communication network  

US Patent & Trademark Office Database

A system, method, and article of manufacture are provided for obtaining information on a mobile computing environment utilizing a distributed communication network. A pattern template is generated. This pattern template is stored on a thin client computer. A query is then created on the thin client computer based in part on user input. A network is queried for information utilizing a distributed communication network. A response is then received to the query from the distributed communication network. This response is processed utilizing an application tool on the thin client computer. The response is filtered by the application tool based on the pattern template. Information is then displayed to a user.

Gershman; Anatole Vitaly (Chicago, IL); Swaminathan; Kishore Sundaram (Downers Grove, IL); Meyers; James L. (Chicago, IL); Fano; Andrew Ernest (Evanston, IL)

2001-03-06

240

User profile replication with caching for distributed location management in mobile communication networks  

Microsoft Academic Search

Location management is an essential process in future mobile communication networks. An important issue is an efficient man- agement of the location database. In this paper, the next genera- tion mobile communication network is proposed to be integrated with a TINA-compliant architecture enabled to handle that kind of mobile-specific processes. This paper discusses the design, and its modeling and comparison

Hoang Nguyen Minh; Harmen R. van As

2001-01-01

241

Notes on the Interplay of Research on Media Space and Mobile Communication  

Microsoft Academic Search

In this chapter, we argue for the mutual relevance of media space and mobile communications researches. Surveying the two literatures, we note that the findings of media space research are often echoed by later mobile communication research and discuss some of the ideas they hold in common. However, mobile phones are used in a more diverse environment, both organizationally and

Paul M. Aoki; Margaret H. Szymanski; Allison Woodruff

242

Research of Mobile Banking Service in China: A Cross Rode of Communication Technology and Financial Innovation  

Microsoft Academic Search

The research and comparative of the experiences that mobile phone banking business developed in different countries demonstrates that with the development of communication technology and its support, phone banking as a combination of electronic money and mobile communications has become an example that IT leads the development of finance. After exploring lots of convenience and advantages that mobile banking can

Sheng Min; Chi Fei

2009-01-01

243

Network and protocol architectures of hybrid multimedia mobile access communication system  

Microsoft Academic Search

We present a network architecture of the hybrid multimedia mobile access communication (MMAC) system through which a number of broadband multimedia mobile communication services are provided for hand-held, small radio terminals. In the hybrid MMAC system, the conventional personal communication system (PCS) link is used for uplinks while the broadband radio link under development in the MMAC Promotion Council is

T. Sakamoto; K. Tsunoda; E. Kamagata; M. Serizawa

1999-01-01

244

On the electromagnetic compatibility in construction of microcellular mobile communication networks  

Microsoft Academic Search

The microcellular mobile radio systems are widely utilized in the third generation of digital mobile communication networks, and will certainly be applied in the forthcoming personal communication networks as well. However, we still have no strict definition so far for the so-called “microcell area” in the urban wireless communication environment. Roughly speaking, the microcell implies such a region in which

Zhu Hongbo; Cao Wei

1998-01-01

245

Jitter compensation on the downlink of future mobile multimedia communications systems  

Microsoft Academic Search

Not only is the amount of packet traffic carried on mobile communications networks growing, it is also anticipated that such communication networks will eventually use packet-based backbone and core networks. Considering this, characteristics of packet (IP) traffic such as delay jitter will be of growing significance to the performance of these mobile communications systems. Not only will such characteristics affect

Glenn Platt; Jamil Y. Khan

2003-01-01

246

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

247

User requirements for interruption management in mobile communications in hospitals.  

PubMed

In hospitals, mobile communication devices increase the occurrence of inappropriate interruptions during clinical task performance. These interruptions have been related to decreased quality of clinical care. User requirements were elicited using a scenario based approach. The results present insights into user requirements for an interruption management system for hospitals. Hospital workflow protocols were identified as a major source of interruptions. Many suggestions for managing these interruptions related to improving workflow using IT. We have shown that even though the hospital is an exceptionally demanding environment, the user requirements for interruption management concur with earlier findings in the broader fields of context aware interruption management and computer supported cooperative work. PMID:23920869

Talsma, Bernd G; Solvoll, Terje; Hartvigsen, Gunnar

2013-01-01

248

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

249

Optimizing Frequency Hopping in GSM Cellular Phone Networks  

Microsoft Academic Search

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

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

2002-01-01

250

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

251

An Analysis of Fixed-Mobile Communications Convergence: Development, Social Benefits and Markets  

Microsoft Academic Search

In recent years, global mobile telephony has experienced a spectacular growth never presented in the long history of fixed network based communications. The International Telecommunications Union indicated that, in 2002, the number of mobile subscribers surpassed the number of fixed main lines in service for the first time. This mobile service adoption growth might suppose that the mobile telephone original

Claudio Feijoo; J. L. Gomez-Barroso; Sergio Ramos; D. Rojo

2006-01-01

252

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

253

GSM 900 MHz cellular phone radiation can either stimulate or depress early embryogenesis in Japanese quails depending on the duration of exposure.  

PubMed

Abstract Purpose: Our study was designed to assess the effects of low intensity radiation of a GSM (Global System for Mobile communication) 900 MHz cellular phone on early embryogenesis in dependence on the duration of exposure. Materials and methods: Embryos of Japanese Quails were exposed in ovo to GSM 900 MHz cellular phone radiation during initial 38 h of brooding or alternatively during 158 h (120 h before brooding plus initial 38 h of brooding) discontinuously with 48 sec ON (average power density 0.25 ?W/cm(2), specific absorption rate 3 ?W/kg) followed by 12 sec OFF intervals. A number of differentiated somites were assessed microscopically. Possible DNA damage evoked by irradiation was assessed by an alkaline comet assay. Results: Exposure to radiation from a GSM 900 MHz cellular phone led to a significantly altered number of differentiated somites. In embryos irradiated during 38 h the number of differentiated somites increased (p < 0.001), while in embryos irradiated during 158 h this number decreased (p < 0.05). The lower duration of exposure led to a significant (p < 0.001) decrease in a level of DNA strand breaks in cells of 38-h embryos, while the higher duration of exposure resulted in a significant (p < 0.001) increase in DNA damage as compared to the control. Conclusion: Effects of GSM 900 MHz cellular phone radiation on early embryogenesis can be either stimulating or deleterious depending on the duration of exposure. PMID:23578013

Tsybulin, Olexandr; Sidorik, Evgeniy; Brieieva, Olga; Buchynska, Lyubov; Kyrylenko, Sergiy; Henshel, Diane; Yakymenko, Igor

2013-05-13

254

A review of earth observation using mobile personal communication devices  

NASA Astrophysics Data System (ADS)

Earth observation using mobile personal communication devices (MPCDs) is a recent advance with considerable promise for acquiring important and timely measurements. Globally, over 5 billion people have access to mobile phones, with an increasing proportion having access to smartphones with capabilities such as a camera, microphone, global positioning system (GPS), data storage, and networked data transfer. Scientists can view these devices as embedded sensors with the potential to take measurements of the Earth's surface and processes. To advance the state of Earth observation using MPCDs, scientists need to consider terms and concepts, from a broad range of disciplines including citizen science, image analysis, and computer vision. In this paper, as a result of our literature review, we identify a number of considerations for Earth observation using MPCDs such as methods of field collection, collecting measurements over broad areas, errors and biases, data processing, and accessibility of data. Developing effective frameworks for mobile data collection with public participation and strategies for minimizing bias, in combination with advancements in image processing techniques, will offer opportunities to collect Earth sensing data across a range of scales and perspectives, complimenting airborne and spaceborne remote sensing measurements.

Ferster, Colin J.; Coops, Nicholas C.

2013-02-01

255

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

NASA Astrophysics Data System (ADS)

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

1993-08-01

256

77 FR 28797 - Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection...  

Federal Register 2010, 2011, 2012, 2013

...Communications Systems: Backup Power Private Land Mobile Radio Services...deletes a rule setting forth backup power requirements for communications...deletes a rule providing that UHF television translators on Channels...such operations. There are no UHF television translators...

2012-05-16

257

Multi-purpose HealthCare Telemedicine Systems with mobile communication link support  

PubMed Central

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

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

2003-01-01

258

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

259

Design of base station antenna using ACP technology for mobile communication  

Microsoft Academic Search

Mobile communication is in ever expanding demand. To cater for the rapid increase in the number of users, the overall capacity of the service must be increased. A very important component of any mobile communication system is the base station antenna. In this work, a single element patch antenna was designed using the ACP technique, operating at 1.8 GHz, which

A. Sherwal; N. Tran

2001-01-01

260

A Simulation Study for Allocation of Base Stations in Mobile Communication Networks  

Microsoft Academic Search

In actual mobile communication networks, the users' locations, the number of mobile communication users, and their behavior change depending on the time zone. This dependency affects the cell traffic; thus, the allocation of base stations (BSs) in the service area is an important problem to be investigated. In this paper we propose a new model for allocation of BSs in

Takako Yamada; Yukio Takahashi; Leonard Barolli; Norio Shiratori

2001-01-01

261

A Method for Simulating the Random Workload of a Base Station for Mobile Communications  

Microsoft Academic Search

A method is introduced in this paper for computer simulation of the random workload of a base station for mobile communications. The workload of a base station is characterised by state parameters, such as the number of subscribers and number of mobile phones currently in communication with services provided by the base station, etc. For given estimates of the state

Peng Huang; Yunxian Pi; J. Yu

2006-01-01

262

Analysis of propagation path for location of base-station in the microcell CDMA mobile communications  

Microsoft Academic Search

In microcell mobile communication, we analyze the propagation path which can accurately and rapidly interpret mobile communication propagation in an urban environment, when the subscriber service is based on the urban main road. To find the appropriate BS location in an urban street, we suggest a simplified algorithm to interpret the propagation path and a propagation prediction model which can

Sun-Kuk Noh; Chang-Gyun Park

2004-01-01

263

A study of multi-hop mobile communication access models considering elapsed time from coverage area  

Microsoft Academic Search

In this paper, we focus on multi-hop mobile communication. We propose a mobile communication model that able to connect to base-station by using multi-hop, when some nodes are in the outside of the coverage area of basestations. At first, we examine the \\

Yukiko Nasu; Shigeru Shimamoto

2005-01-01

264

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

265

A Picture and a Thousand Words: Visual Scaffolding for Mobile Communication in the Developing World  

Microsoft Academic Search

Mobile communication is a key enabler for economic, social and political change in developing regions of the world. Today's internet-enabled, multimedia, and touch-screen mobile smartphones could become the future platform for delivering information and communication technology (ICT) to these regions. We describe Picture Talk, a smartphone application framework designed to facilitate local information sharing in regions with sparse Internet connectivity,

Robert Farrell; Catalina Danis; Thomas Erickson; Jason Ellis; Jim Christensen; Mark Bailey; Wendy A. Kellogg

2009-01-01

266

Optimum multi-layered cell architecture for personal communication systems with high degree of mobility  

Microsoft Academic Search

The paper presents a multi-layer structure for personal communications services (PCS). An evaluation is shown for low and high mobility of PCS in terms of cost economy, capacity and spectrum usage. It is supposed that the service area with 30 km radius is covered by a multiple micro cells in the low mobility plane, while the high-mobility plane employs macro

Keisuke Ogawa; Takeshi Hattori; Hiroshi Yoshida

1994-01-01

267

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

Microsoft Academic Search

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

Zhiwei Cen; Hong Chen; Xiaomei Liu

268

Implications of Mobility: The Uses of Personal Communication Media in Everyday Life  

Microsoft Academic Search

This study examined the impact of mobile communications on interpersonal relation- ships in daily life. Based on a nationwide survey in Japan, landline phone, mobile voice phone, mobile mail (text messaging), and PC e-mail were compared to assess their usage in terms of social network and psychological factors. The results indicated that young, nonfamily-related pairs of friends, living close to

Kenichi Ishii

2006-01-01

269

Towards a Model of Seamless Mobility - User Value and Security in Computing, Content, and Communications  

Microsoft Academic Search

Seamless mobility is a term that encompasses a broad range of technologies and applications. It builds on technology developments in the wireless industry over the last 20 years, starting with mobile telephony, on through mobile IP, convergence of voice and data, and now towards an ever-increasing rate of convergence\\/collision between the worlds of secure communication, content, and computing. It is

Jeena Srinivas; Stephen Chen

2005-01-01

270

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

NASA Astrophysics Data System (ADS)

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

Yairi, Ikuko Eguchi; Igi, Seiji

271

Performance Analysis of Location-Aware Mobile Service Proxies for Reducing Network Cost in Personal Communication Systems  

Microsoft Academic Search

We propose and analyze mobile service management schemes based on location-aware proxies with the objective to reduce the network signaling and communication cost in future personal communication systems (PCS). Under these schemes, a mobile user uses personal proxies as intelligent client-side agents to communication with services engaged by the mobile user. A personal proxy cooperates with the underlying location management

Baoshan Gu; Ing-ray Chen

2005-01-01

272

International Conference on Satellite Systems for Mobile Communications and Navigation, 4th, London, England, Oct. 17-19, 1988, Proceedings  

NASA Astrophysics Data System (ADS)

Attention is given to the following topics: antennas and propagation, systems for communication, systems for land mobile communications, systems for aeronautical communications, and system economics, operation, and traffic. Particular papers are presented on tracking receiver design for the electronic beam squint tracking system in the maritime mobile environment, network signalling system design considerations in a multiservice mobile satellite communication systems, Inmarsat's aeronautical satellite communication system, and proposed systems configurations for a satellite-based ISDN.

273

MODELING OF WIRELESS MOBILE COMMUNICATION SYSTEM USING Z NOTATION  

Microsoft Academic Search

In this paper, we make an effort to model complex and dynamic domain of wireless mobile networks using emerging software engineering practices. Wireless mobile networks enable user to access information and services at any geographic location. The major setback of existing wireless network models is the poor service quality and undesirable user disconnections due to mobility. Formal method is the

Saima Tariq; Nazir Ahmad Zafar

274

Mobile TV Becomes Social - Integrating Content with Communications  

Microsoft Academic Search

Mobile TV is a class of pervasive multimedia services which currently enjoys considerable scientific and commercial attention. In this paper, we propose the integration of peer-to-peer interactivity as one likely Mobile TV evolution path. We integrate findings from related fields to develop a definition of Mobile Social TV and outline its design space in order to discuss opportunities of integrating

Raimund Schatz; Siegfried Wagner; Sebastian Egger; Norbert Jordan

2007-01-01

275

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

NASA Astrophysics Data System (ADS)

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

Sharawi, Mohammad S.; Aloi, Daniel N.

2003-08-01

276

Nar Kommunikasjonen Mobiliseres. En Kunnskapsstatus om Samspill Mellom IKT og Personlig Mobilitet (Mobilization of Communication).  

National Technical Information Service (NTIS)

This report examines the interplay between mobility transport and the use of information and Communication Technology. The report identifies three important strands of research-within transportation, ICT and urban geography-that have examined this interpl...

M. Gripsrud

2007-01-01

277

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

278

Distributed Mobile Communication Base Station Diagnosis and Monitoring Using Multi-agents  

Microsoft Academic Search

Most inherently distributed systems require self diagnosis and on-line monitoring.This is especially true in the domains of power transmission and mobile communication.Much effort has been expended in developing on-site monitoring systems for distributed power trans- formers and mobile communication base stations.In this paper, a new approach has been employed to implement the autonomous self diagno- sis and on-site monitoring using

J. Q. Feng; D. P. Buse; Q. H. Wu; J. Fitch

2002-01-01

279

Propagation Path Analysis for Location Selection of Base-Station in the Microcell Mobile Communications  

Microsoft Academic Search

\\u000a In microcell mobile communication using cellular method, we analyze propagation path which can accurately and rapidly interpret\\u000a mobile communication propagation environment in urban, when subscriber service is done based on the main road in urban.  In\\u000a this paper, to appropriate location of BS in urban street, we suggest a simplified algorithm to interpret a propagation path\\u000a and a propagation prediction

Sun-kuk Noh; Dong-you Choi; Chang-kyun Park

2005-01-01

280

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

Microsoft Academic Search

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

Xiaoxing Yin; Xinyu Zai; Wei Hong; Xiaowei Zhu

1999-01-01

281

On the Correlation and Scattering Functions of the WSSUS Channel for Mobile Communications  

Microsoft Academic Search

The wide-sense stationary-uncorrelated scattering (WSSUS) channel model is a commonly employed model for the multipath channel experienced in mobile communications. The second-order statistics of these channels are described by the delay cross-power density or by its -Fourier transform, the scattering function . This paper presents an analysis of the delay cross-power density and scattering functions for mobile communications channels. We

John S. Sadowsky; Venceslav Kafedziski

1998-01-01

282

On the correlation and scattering functions of the WSSUS channel for mobile communications  

Microsoft Academic Search

The wide-sense stationary-uncorrelated scattering (WSSUS) channel model is a commonly employed model for the multipath channel experienced in mobile communications. The second order statistics of these channels are described by the delay cross-power density ?h(?;?t) or by its ?t-Fourier transform, the scattering function Sh(?;?). This paper presents an analysis of the delay cross-power density and scattering functions for mobile communications

John S. Sadowsky; Venceslav Kafedziski

1998-01-01

283

An Adaptive Compulsory Protocol for Basic Communication in Highly Changing Ad hoc Mobile Networks  

Microsoft Academic Search

In this paper we study the problem of basic communication in ad-hoc mobile networks where the deployment area changes in a highly dynamic way and is unknown. We call such networks highly changing ad-hoc mobile networks. For such networks we investigate an efficient communication protocol which extends the idea (introduced in [4, 6]) of exploiting the co-ordinated motion of a

Ioannis Chatzigiannakis; Sotiris E. Nikoletseas

2002-01-01

284

Overview of NASA Glenn Aero/Mobile Communication Demonstrations.  

National Technical Information Service (NTIS)

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 techn...

D. Brooks D. Hoder R. Wilkins

2004-01-01

285

Overview of NASA Glenn Aero/Mobile Communications Demonstrations.  

National Technical Information Service (NTIS)

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 techn...

D. Brooks D. Hoder R. Wilkins

2004-01-01

286

Case Study in Mobile Internet Innovation: Does Advertising or Acquaintances Communication Decide Taiwan's Mobile Internet Diffusion?  

Microsoft Academic Search

Reporting the world's highest mobile phone penetration rate in 2002, Taiwan's experience in promoting mobile phone has offered global scholars a successful example in innovation marketing. Its current mobile Internet status is therefore received great attentions from international practitioners and researchers. However, despite various marketing efforts, Taiwan's mobile Internet services' diffusion is surprisingly slower than that of Korea and Japan.

Hui-chih Wang; Yi-cheng Ku; Her-sen Doong

2007-01-01

287

A Crisis Communication Network Based on Embodied Conversational Agents System with Mobile Services  

Microsoft Academic Search

In this paper, we proposed a new framework to incorporate an intelligent agent software robot into a crisis communication portal (CCNet) in order to send alert news to subscribed users via email and other mobile services such as Short Message Service (SMS), Multimedia Messaging Service (MMS) and General Packet Radio Services (GPRS). The content on the mobile services can be

Ong Sing Goh; Cemal Ardil; Kok Wai Wong; Arnold Depickere

288

Study of LEO-SAT Microwave Link for Broad-Band Mobile Satellite Communication System.  

National Technical Information Service (NTIS)

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 degr...

M. Fujise W. Chujo I. Chiba Y. Furuhama K. Kawabata

1993-01-01

289

Improving the Communication of Spatial Information in Crisis Response by Combining Paper Maps and Mobile Devices  

Microsoft Academic Search

Ecient and eective communication between mobile units and the central emergency operation center is a key factor to respond successfully to the challenges of emergency management. Nowadays, the only ubiquitously available modality is a voice channel through mobile phones or radio transceivers. This makes it often very dicult to convey exact geographic locations and can lead to misconceptions with severe

Johannes Schoning; Michael Rohs; Antonio Kruger; Christoph Stasch

290

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

Microsoft Academic Search

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

Yannis Labrou; Timothy W. Finin; Yun Peng

1999-01-01

291

Fear and anger: antecedents and consequences of emotional responses to mobile communication  

Microsoft Academic Search

Many people fear that exposure to mobile phone base stations leads to severe health effects. In addition to those fears, many citizens are unsatisfied or even angry about prevailing base station site-selection procedures. In the present study, it was investigated how these emotions, i.e. fear and anger, determine risk and benefit perceptions and the acceptance of mobile communication. Using structural

Simone Dohle; Carmen Keller; Michael Siegrist

2012-01-01

292

Polarisation of Electromagnetic Waves Analysis for Application in Mobile Communication Systems  

Microsoft Academic Search

The polarisation property of electromagnetic waves for applications in mobile communication systems has not been examined into detail yet. Due to multi-path effects and changes in the underlying coordinate systems of the involved antennas, the polarisation state of an electromagnetic wave at the receiving antenna of a mobile station is very likely to change. The presented project involves a data

J. Dousa; G. Wanielik

2006-01-01

293

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

Microsoft Academic Search

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

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

1994-01-01

294

A Novel Algorithm for Uplink Interference Suppression Using Smart Antennas in Mobile Communications  

Microsoft Academic Search

In recent years there has been an explosive growth in the number of wireless users, particularly in the area of mobile communication. In future, wireless mobile systems will be more sophisticated and more widespread. This growth has triggered an enormous demand not only for capacity but also better coverage and higher quality of service. Several new technologies have been explored

Kiran Kumar Shetty

2004-01-01

295

Fear and anger: antecedents and consequences of emotional responses to mobile communication  

Microsoft Academic Search

Many people fear that exposure to mobile phone base stations leads to severe health effects. In addition to those fears, many citizens are unsatisfied or even angry about prevailing base station site-selection procedures. In the present study, it was investigated how these emotions, i.e. fear and anger, determine risk and benefit perceptions and the acceptance of mobile communication. Using structural

Simone Dohle; Carmen Keller; Michael Siegrist

2011-01-01

296

The Process of Developing a Mobile Device for Communication in a Safety-Critical Domain  

Microsoft Academic Search

This paper describes the process of developing an interactive mobile system for use in a safety-critical domain. The system was developed to inquire into the extent of which coordination between people carrying out a collaborative work task can be improved by means of computer mediated communication on a mobile device. The application area for the device was controlling and monitoring

Jesper Kjeldskov; Jan Stage

2003-01-01

297

Design of the Access Network Segment of Future Mobile Communications Systems  

Microsoft Academic Search

An important component of future mobile communications systems is their access network segment that enables interworking between the mobile unit and the fixed network. In this paper we define and solve two important problems, related to the design of this segment. First, the efficient utilisation of the available radio spectrum. In this context we present a scheme that may be

E. C. Tzifa; V. P. Demesticha; P. P. Demestichas; M. E. Theologou; M. E. Anagnostou

1999-01-01

298

Mobile WiMAX-based communication network planning in Seribu Island by utilizing existing towers  

Microsoft Academic Search

An archipelago consisting of number of islands is relying on the broadband wireless technology to facilitate its telecommunication service. Mobile WiMAX (Worldwide Interoperability Mobile Access), as one of the broadband wireless technologies, is proposed to be applied as the network deployment in this paper. The network planning is designed based on cellular communication systems using hexagonal cells model. Five islands

Hardi Nusantara; Zaki Mujahid; Achmad Munir

2011-01-01

299

An Improved Low Computation Cost User Authentication Scheme for Mobile Communication  

Microsoft Academic Search

Most of existing user authentication schemes require high computation cost of exponentiation operations for the purpose of security. However, it is not suitable for mobile devices. In this article, we propose a low computation cost user authentication scheme for mobile communication. Our scheme uses only one-way hash functions and smart cards and can be implemented efficiently. The proposed scheme not

Chia-yin Lee; Chu-hsing Lin; Chin-chen Chang

2005-01-01

300

Two Decades of U. S. Army Mobile High-Frequency Communications  

Microsoft Academic Search

This paper is an historical account of the trend in development of U. S. Army high-frequency mobile radio communications of medium power in the period 1940 to 1960. Starting with one of the first really mobile sets of this power level, in a wide variety of installation configurations to meet World War II requirements, it relates the progressive fulfillment of

H. C. Hawkins

1960-01-01

301

A Study on the Performance Evaluation of Forward Link in CDMA Mobile Communication Systems  

Microsoft Academic Search

\\u000a In the CDMA cellular mobile communication systems, the connection between base and mobile station has a forward link from\\u000a base station to mobile station. Four channels of forward link, pilot channel, sync channel, paging channel, traffic channel,\\u000a have an absolute influence on forward coverage and speech quality. And overhead channels(pilot, sync, paging) are assigned\\u000a output at the adequate rate to

Sun-kuk Noh

2005-01-01

302

Effect of Grouping in Local Communication System of Multiple Mobile Robots  

Microsoft Academic Search

For the cooperation in a large system with many mobile robots, local communication system is considered appro- priate in terms of the cost and capacity of communica- tion. The behavior of robots has a respectable effect on the efficiency of communication in such a local commu- nication system and it is essential to know what kind of behavior robots should

Eiichi YOSHIDA; Tamio ARAI Jun OTA; Tomoyoshi MIKI

1994-01-01

303

Vehicle Mobility Characterization Based on Measurements and Its Application to Cellular Communication Systems  

Microsoft Academic Search

SUMMARY Future cellular communication systems will be called upon to provide multimedia services (voice, data, and video) for various user platforms (pedestrians, cars, and trains) that have a variety of mobility characteristics. Knowledge of mo- bility characteristics is essential for planning, designing and oper- ating communication networks. The position data of selected ve- hicles (taxis) have been measured by using

Takehiko KOBAYASHI; Noriteru SHINAGAWA; Yoneo WATANABE

1999-01-01

304

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

Microsoft Academic Search

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

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

2007-01-01

305

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

306

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

307

Secure groups communication for mobile agents based on public key infrastructure  

Microsoft Academic Search

The use of mobile agents based computing in this emerging world of electronic transaction is becoming increasingly prevalent due to the enormous benefits and services that can be derived from it. They are good for distributed applications and hence an excellent paradigm when group communications are involved. Secure group communication is a significant research area prompted by the growing popularity

Muhammad Aiman Mazlan; Azman Samsudin; Rahmat Budiarto

2003-01-01

308

On mobile communications smart base-station system design  

Microsoft Academic Search

A design technique for mobile base-station antennas is presented. Beam tilting to avoid intersymbol interference is considered, and the orthogonal method (OM) under constraints on the radiation pattern is applied. The adaptive architecture of the mobile system, in conjunction with the direction of arrival (DoA) and the least mean square algorithms, is explained. A set of useful examples shows the

G. Miaris; E. Slachaloou; Theodoros Samaras; Sotirios Goudos; Elias Vafiadis; S. Panas

2005-01-01

309

Discovery and Integration of Mobile Communications in Everyday Life  

Microsoft Academic Search

We report on the results of a study in which 19 new mobile telephone users were closely tracked for the first six weeks after service acquisition. Results show that novices tend to rapidly modify their perceptions of social appropriateness around mobile phone use, that actual nature of use frequently differs from initial predictions, and that comprehension of service-based technologies can

Leysia Palen; Marilyn C. Salzman; Ed Youngs

2001-01-01

310

Communication of risk: health hazards from mobile phones  

Microsoft Academic Search

Possible health hazards from mobile phones arise from the use of the phones themselves and via the base stations that relay signals. Except for an increase in traffic accidents induced by the use of mobile phones in cars the evidence for a health hazard is at most indirect, but it cannot be entirely dismissed; the phones have not been widely

D. R. Cox

2003-01-01

311

Maintaining Optimal Communication Chains in Robotic Sensor Networks using Mobility Control  

Microsoft Academic Search

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

Cory Dixon; Eric W. Frew

2009-01-01

312

The application of the diversity in mobile free-space optical communication  

Microsoft Academic Search

Traditional free-space optical (FSO) communications use a single transmitting antenna (laser\\/VCSEL\\/LED) and a receiving antenna (a photo-detector) for single channel communication between two nodes. In this paper we study two transmitting antenna one receiving antenna M-FSO (mobile FSO) communication system. In the process of single transmitting antenna moving, the optical beam broadens to make receive power smaller with the divergence

Yingchun Li; Rui Zhang

2008-01-01

313

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

2013-07-22

314

Influence of mobile phones on accuracy of ECG interpretation algorithm in automated external defibrillator  

Microsoft Academic Search

Background: Automated External Defibrillators (AED) are a recommended tool for out-of-hospital emergency medical services. Mobile phones (GSM) are a potential source of electromagnetic interference which may cause failure of ECG interpretation and subsequent inappropriate action of AED's. Methods: We evaluated the influence of 900 MHz GSM phones on the accuracy of automatic ECG interpretation with a GSM Mobile Station Tester

Stefan Karczmarewicz; Dariusz Janusek; Tomasz Buczkowski; Robert Gutkowski; Piotr Ku?akowski

2001-01-01

315

Network design consideration of a satellite-based mobile communications system  

NASA Astrophysics Data System (ADS)

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

Yan, T.-Y.

316

Advanced Mobile Communications for Emergency Management and Crisis Response  

Microsoft Academic Search

Reliable communications can be a matter of life-and-death during an emergency or crisis. First responder communication system interoperability, coverage, and flexibility are among the most critical issues evident from events such as the terrorist attacks of September 11 2001, the Indian Ocean Tsunami of 2004, and Hurricane Katrina. Murray State University and research partners are addressing these issues under grants

Michael Bowman

317

(Auto) mobile communication in a heterogeneous and converged world  

Microsoft Academic Search

In this article we discuss services and system architecture issues for future wireless communication in the vehicular environment. We consider the problem of wireless network heterogeneity that will be a consequence of emerging technologies such as wireless LANs, ad hoc networks, and broadcast systems, in addition to third-generation cellular standards like UMTS. In particular, a communication gateway architecture is proposed

Wolfgang Kellerer; Christian Bettstetter; Christian Schwingenschlögl; Peter Sties

2001-01-01

318

Satellite-aided mobile communications: Experiments, applications, and prospects  

Microsoft Academic Search

NASA's application technology satellites (ATS) 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, medical emergency, and for commercial uses in the land and maritime transportation industries. The technical success of the experiments and the demonstrated

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

1981-01-01

319

Satellite-aided mobile communications, experiments, applications and prospects  

Microsoft Academic Search

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

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

1980-01-01

320

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.

2002-01-01

321

A study on the regulations concerning base stations for next-generation mobile communications networks in Korea  

Microsoft Academic Search

Mobile communications services, which offer one way to realize the informed society of the 21st century, have developed rapidly worldwide. With the commercialization of CDMA 2000-1× late in 2000, a high-speed wireless Internet, based on a mobile communication network, appeared in Korea. This will develop into the next-generation of mobile communications (4G) with faster transmission of increased volumes of data

2004-01-01

322

Adaptive Transceivers for Mobile Free-Space Optical Communications  

Microsoft Academic Search

Free-space optical (FSO) communication links are susceptible to a tremendous amount of variability and offer a real challenge for efficient, robust system design. Whether changes in link margin are predictable (i.e. weather conditions or mission profiles) or truly random (i.e. atmospheric turbulence induced scintillation or boundary layer induced tracking errors), FSO communication systems will experience a large dynamic range of

Jeffrey R. Minch; David R. Gervais; Daniel J. Townsend

2006-01-01

323

Mobile phones and elderly people: a noisy communication.  

PubMed

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

Stamato, Cláudia; Moraes, Anamaria de

2012-01-01

324

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  

Microsoft Academic Search

The exposure of male mice to radiofrequency radiations from mobile phone (GSM) base stations at a workplace complex and residential\\u000a quarters caused 39.78 and 46.03%, respectively, in sperm head abnormalities compared to 2.13% in control group. Statistical\\u000a 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.

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

2010-01-01

325

Particle swarm optimization for base station placement in mobile communication  

Microsoft Academic Search

The tremendous growth in the demand for mobile services results in an explosion in base station (BS) density and network complexity, making the conventional manual planning processes highly inefficient. In this paper, we give some novel adaptation to the recent bio-inspired optimization approach, Particle Swarm Optimization (PSO), to form a suitable algorithm for the base station placement problem. Considering the

Zhang Yangyang; Ji Chunlin; Yuan Ping; Li Manlin; Wang Chaojin; Wang Guangxing

2004-01-01

326

Efficient and secure keys management for wireless mobile communications  

Microsoft Academic Search

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

Roberto Di Pietro; Luigi V. Mancini; Sushil Jajodia

2002-01-01

327

Enhancement of Bridge Management System (BMS) with Mobile Communication Technology  

Microsoft Academic Search

The accumulated BMS data is helpful for decisionmaking for bridge maintenance and repair work. This study developed the methodology for the application of mobile Internet-based KOBMS for bridge management with the PDA, by providing the basic scheme of the data flow for BMS is the most important.

Tai Sik Lee; Dong Wook Lee; Young Hyun Kim; Jeong Hyun Kim

2005-01-01

328

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

329

Convolutional Turbo Coded OFDM\\/TDD Mobile Communication System for High Speed Multimedia Services  

Microsoft Academic Search

A novel mobile Internet access system based on the OFDM transmission technique is proposed and its performance is analyzed via computer simulations. Especially, OFDM is considered in combination with the TDMA\\/TDD scheme for a cellular mobile communication system. We present simulation results for the performance of a convolutional turbo coded OFDM\\/TDD system with QPSK, 16QAM, and 64QAM over ITU-R channel

Seong Chul Cho; Jin Up Kim; Kyu Tae Lee; Kyoung-rok Cho

2005-01-01

330

Improving the Communication of Spatial Information in Crisis Response by Combining Paper Maps and Mobile Devices  

Microsoft Academic Search

Efficient and effective communication between mobile units and the central emergency operation center is a key factor to respond\\u000a successfully to the challenges of emergency management. Nowadays, the only ubiquitously available modality is a voice channel\\u000a through mobile phones or radio transceivers. This makes it often very difficult to convey exact geographic locations and can\\u000a lead to misconceptions with severe

Johannes Schöning; Michael Rohs; Antonio Krüger; Christoph Stasch

2008-01-01

331

Co-channel interference cancellation for DS-SS CDMA mobile communication system  

Microsoft Academic Search

In this paper, an elaborate co-channel interference (CCI) cancellation technique is introduced for the DS-SS CDMA mobile communication system. The performance of the CCI canceller (Yoon, et al., 1993) is extended and evaluated at the mobile station (MS) receiver operating in an extreme (worst) interference condition. The interference is a result of intersymbol interference (ISI) and multi-access interference (MAI) generated

K. M. Shaheen; Someshwar C. Gupta

1995-01-01

332

Design of multibeam CORPS-BFN for cellular mobile communications systems  

Microsoft Academic Search

The design of a beam-forming network (BFN) for multibeam-steerable antenna array using Coherently Radiating Periodic Structures (CORPS) in cellular mobile communication systems is presented. In this work, CORPS technology as a BFN is introduced in cellular systems. The CORPS-BFN proposed improves the performance over commonly used feeding networks used on mobile systems. The feeding ports of the network design are

Armando Arce-Casas; David H. Covarrubias Rosales; Marco A. Panduro Mendoza

2011-01-01

333

OFDM for data communication over mobile radio FM channels. I. Analysis and experimental results  

Microsoft Academic Search

The performance of OFDM\\/FM modulation for digital communication over Rayleigh-fading mobile radio channels is described. The use of orthogonal frequency division multiplexing (OFDM) over mobile radio channels was proposed by Cimini (1985). OFDM transmits blocks of bits in parallel and reduces the bit error rate (BER) by averaging the effects of fading over the bits in the block. OFDM\\/FM is

Eduardo F. Casas; C. Leung

1991-01-01

334

Mobile Communication in the Public Mind: Insights from Free Associations Related to Mobile Phone Base Stations  

Microsoft Academic Search

The number of people using mobile phones has dramatically increased. At the same time, many people are unsettled about the potential health effects from the electromagnetic fields generated by mobile phone base stations. Research indicates that the risks associated with base stations are perceived differently by experts, laypeople, and base station opponents. Using a free association method, we analyzed these

Simone Dohle; Carmen Keller; Michael Siegrist

2012-01-01

335

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

336

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

337

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

338

Mobile Communication Implementation Techniques to Improve Last Mile High Speed FSO Communication  

Microsoft Academic Search

\\u000a As an affordable alternative solution for the current generation last mile wireless communication network access, the FSO\\u000a – Free Space Optical Communication has vast development in supporting of FSO communication. The primary advantages of FSO\\u000a system are the license free optical nodes, higher data rates, easy to install with less expensive setup. However, obtaining\\u000a the reliable communication link and higher

R. Srinivasan; A. Vijayaraj

339

Experimental advanced mobile satellite communications system in mm-wave and Ka-band using Japan's COMETS  

NASA Astrophysics Data System (ADS)

The Communications Research Laboratory (CRL) has been studying an advanced mobile satellite communications system using millimeter wave and Ka band in the Communications and Broadcasting Engineering Test Satellite (COMETS) project. The project started in 1990 and the satellite will be launched in 1997. Onboard multibeam interconnecting is one of the basic functions to realize onehop connection among mobile and hand held terminals and Very Small Aperture Terminals (VSAT's) in future mobile satellite communications systems. 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 COMETS for experiment is shown. High power transmitters of millimeter wave and Ka bands, a 3 by 3 IF filter bank, and Single Channel Per Carrier/Time Division Multiplexing (SCPC/TDM) regenerative modems are the purpose of studying the feasibility of advanced mobile communications systems.

Isobe, S.; Hamamoto, N.; Takeuchi, M.; Ohmori, S.; Yamamoto, M.

1991-10-01

340

Passive Radar using Multiple GSM Transmitting Stations  

Microsoft Academic Search

The atmosphere has a wide range of transmissions available from various sources like TV transmissions, GSM signals, FM Radio, AM Radio, GPS signals, etc. These signals open up the opportunity of designing different types of passive radars. Passive radar using a single GSM transmitting station have been designed, but this type of radar cannot give accurate target parameters. This paper

U. M. D. Mendi; B. K. Sarkar

2006-01-01

341

TMN as applied to the GSM network  

Microsoft Academic Search

Reviews some of the guiding principles of TMN that were applied, or consciously not applied, to the development of GSM network management. The organization of the work within the sub-technical committee and the resultant organization of the specifications are described. The article also introduces the model for the management of a GSM network, as well as some of the philosophy

Thomas T. Towle

1995-01-01

342

Potential Application of Laser Diodes to Free Space Optical Communication Between Mobile On-Sea Terminals  

Microsoft Academic Search

Potential use of medium power, 75 to 150 mW, laser diodes in free space optical communication between mobile on-sea terminals is investigated. For bit rates from 2.4 to 115.2 kbps, the maximum estimated communication distances are presented, considering different sources of ambient radiation by day and night and medium haze atmospheric conditions. The effects of the position and size of

Faruk Ozek

2001-01-01

343

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

344

Automatic device configuration and data validation through mobile communication  

Microsoft Academic Search

The introduction of personal computing and wireless communication technology provides an option for on site device software updating and data retrieving. This is especially true for any devices sitting in a remote site where computing network is not accessible. In many advanced computing systems, frequent software updating and configuration profiles refreshing are required. This is clumsy and error prone procedures

Wai-Leung Cheung; Y. F. Fung; Weizhao Wang; T. M. Chan

2003-01-01

345

Carrier aggregation for LTE-advanced mobile communication systems  

Microsoft Academic Search

In order to achieve up to 1 Gb\\/s peak data rate in future IMT-Advanced mobile systems, carrier aggregation technology is introduced by the 3GPP to support very-high-data-rate transmissions over wide frequency bandwidths (e.g., up to 100 MHz) in its new LTE-Advanced standards. This article first gives a brief review of continuous and non-continuous CA techniques, followed by two data aggregation

Guangxiang Yuan; Xiang Zhang; Wenbo Wang; Yang Yang

2010-01-01

346

An experimental OFDM system for broadband mobile communications  

Microsoft Academic Search

We present an overview of an experimental 20 MHz 2×2 MIMO-OFDM system for operation at 3.65 GHz. The transmitted signal characteristics, data collection setup, measurement analysis, and timing acquisition algorithms are described. Field trials from a base station with two transmit antennas to a two-antenna mobile receiver are planned in a coverage area having a two mile radius. The first

Mickael D. Batariere; James F. Kepler; Thomas P. Krauss; Sandeep Mukthavaram; Jeffrey W. Porter; Frederick W. Vook

2001-01-01

347

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

348

Analysis of Multiantenna Architectures for Non-LOS Mobile-to-Mobile Communications in Cochannel Interference  

Microsoft Academic Search

The performance of multiantenna receivers in cochannel interference is investigated for narrowband links in a non-line-of-sight mobile-to-mobile channel. Channel impairments include Doppler spread and angular spread originating from scatterers in the vicinity of both the transmitter and the receiver. The analysis employs a two-ring scattering model and compares the performance of a sectored system employing selection combining (SC) to the

Thomas G. Pratt; Brett T. Walkenhorst; Heewon Kang

2007-01-01

349

Mobile communications for monitoring heart disease and diabetes.  

PubMed

This paper describes a practical development project to enable the monitoring of vital signs data obtained from patients located in remote rural locations. The data are gathered from a wireless network of sensors attached to a patient's body and stored locally for secure transmission over existing communication infrastructures to a hospital server. Clinicians are then able to monitor the patient offline and upload diagnoses. PMID:21096431

Mulvaney, David; Woodward, Bryan; Datta, Sekharjit; Harvey, Paul; Vyas, Anoop; Thakker, Bashkar; Farooq, Omar

2010-01-01

350

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

351

Analysis of the impact of phase- and amplitude distortions on the beam accuracy of active antenna arrays for mobile communication  

Microsoft Academic Search

In this paper a statistical analysis of the impact of phase- and amplitude-distortions on the performance of active antenna arrays for mobile communication base stations is presented. The cause and influence of different contributors to these distortions is described and the allowable phase- and amplitude-margins that need to be reached for mobile communication base station applications are derived. Finally a

Florian Pivit; Daniel Markert

2010-01-01

352

Implementation of LSCMA adaptive array terminal for mobile satellite communications  

NASA Astrophysics Data System (ADS)

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

Zhou, Shun; Wang, Huali; Xu, Zhijun

2007-11-01

353

Development of software for mobile robot control over a radio frequency communications link  

Microsoft Academic Search

In the spring of 2001, work began on a mobile robot for an advanced computer engineering class. One of the key parts to the success of this robot would be the ability to control it from a computer terminal. In order to make this feasible, the computer would communicate to the robot through a wireless connection. The robot's on-board computer

Matthew B. Lister; Joseph T. Wunderlich

2002-01-01

354

Local map generation using position and communication history of mobile nodes  

Microsoft Academic Search

In this paper, we propose an algorithm to estimate 2D shapes and positions of obstacles such as buildings using GPS and wireless communication history of mobile nodes. Our algorithm enables quick recognition of geography, which is required in broader types of activities such as rescue activities in emergency situations. Nevertheless, detailed building maps might not be immediately available in private

Shinichi Minamimoto; Sae Fujii; Hirozumi Yamaguchi; Teruo Higashino

2010-01-01

355

A middleware for service-oriented communication in mobile disaster response environments  

Microsoft Academic Search

Today, the work of disaster response teams is being increas- ingly supported and coordinated by using portable comput- ing devices. Connected to mobile ad-hoc networks, these devices establish a communication infrastructure immune to damages caused by natural disasters. However, ad-hoc net- works are dynamic and volatile environments, which ham- pers hosting of critical applications relying on fast respon- siveness. These

Lukasz Juszczyk; Schahram Dustdar

2008-01-01

356

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

Microsoft Academic Search

This study report defines a set of tests and measurements required to characterize the performance of a Large Space System (LSS), and to scale this data to other LSS satellites. Requirements from the Mobile Communication Satellite (MSAT) configurations derived in the parent study were used. MSAT utilizes a large, mesh deployable antenna, and encompasses a significant range of LSS technology

W. Akle

1983-01-01

357

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

Microsoft Academic Search

The scarcity and large fluctuations of link bandwidth in wireless networks have motivated the development of adaptive multimedia services in mobile communication networks, where it is possible to increase or decrease the bandwidth of individual ongoing flows. This paper studies the issues of quality of service (QoS) provisioning in such systems. In particular, call admission control and bandwidth adaptation are

Yu Fei; Vincent W. S. Wong; Victor C. M. Leung

2006-01-01

358

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

Microsoft Academic Search

The scarcity and large fluctuations of link bandwidth in wireless networks have motivated the development of adaptive multimedia services in mobile communication networks, where it is possible to increase or decrease the bandwidth of individual ongoing flows. This paper studies the issues of quality of service (QoS) provisioning in such systems. In particular, call admission control and bandwidth adaptation are

Fei Yu; Vincent W. S. Wong; Victor C. M. Leung

2004-01-01

359

Transaction Based Authentication Scheme for Mobile Communication: A Cognitive Agent Based Approach  

Microsoft Academic Search

The vulnerable air interface, device level constraints, and insecure encryption techniques of wireless networks have naturally increased the chance of attacker obtain- ing users information fraudulently. Most of the existing authentication systems for mobile communication princi- pally depends on the strength of authenticating identifiers. Once the client who may be genuine or an attacker, suc- cessfully proves the possession of

B. Sathish Babu; Pallapa Venkataram

2007-01-01

360

A frame synchronization method for adaptive array antennas in digital mobile communications  

Microsoft Academic Search

This paper proposes a frame synchronization method for an adaptive array antenna (AAA) used in digital mobile communications. The proposed scheme, which is based on the maximum likelihood estimation (MLE), calculates error signals by subtracting a training sequence convolved with an estimated channel impulse response from the AAA outputs and searches for the timing that minimizes the mean squared errors.

Kazuhiko Fukawa; Hiroshi Suzuki

2005-01-01

361

VHF maritime mobile communications: A systems approach to serving user requirements  

Microsoft Academic Search

The existing international VHF maritime mobile communication system dates back to the 1947 International Radio Conference at Atlantic City, NJ. At that time, there was formal agreement on the place in the spectrum (built around the use of 156.80 MHz), and informal agreement on the use of a channel bandwidth of 100 kHz. This paper documents the events leading to

J. Renner

1977-01-01

362

The Impact of Mobile Data Terminal (MDT) Information Technology on Communication and Recordkeeping in Patrol Work  

Microsoft Academic Search

The impact of mobile data terminal (MDT) information technology is examined through field research which focuses upon the in-situ uses of the MDT by patrol officers. The impact on patrol officers is reflected in increased proactive work (i.e., traffic) and investigative work not typically the province of patrol, changes in communication patterns between line officers and dispatch and authority relationships

Albert J. Meehan

1998-01-01

363

Towards a secure mutual authentication and key exchange protocol for mobile communications  

Microsoft Academic Search

We analyze several mutual authentication and key exchange protocols (MAKEPs), and present a number of essential properties of the protocols for secure mobile communications. To address the weaknesses of existing protocols, we propose an improved version of MAKEP known as EC-MAKEP. Besides supporting the essential features present in the existing protocols, the proposed protocol also provides the user anonymity and

Yi-Jun He; Moon-Chuen Lee

2008-01-01

364

Investigation of antennas for two-way mobile communications in the VHF and UHF regions  

Microsoft Academic Search

Due to the nature of two-way mobile communications the normal requirement is for base station antennas, as well as the vehicular antennas, to have radiation characteristics which are omnidirectional in azimuth. It is therefore necessary first to investigate the spatial distribution of energy and then to investigate means for confining the radiation in the elevation plane so far as possible

E. F. Harris

1959-01-01

365

The public's knowledge of mobile communication and its influence on base station siting preferences  

Microsoft Academic Search

The present paper explores what people know about mobile communication and how this understanding influences people's perceptions and preferences in regard to this omnipresent technology. As shown in the past, cell phone base station siting often turns out to be a conflictive process. Citizens are not willing to tolerate base stations in their neighbourhoods because they fear health consequences. They

Marie-Eve Cousin; Michael Siegrist

2010-01-01

366

Microstrip patch antenna array for a mobile communication system base station  

Microsoft Academic Search

A dual-band low cost linear array of planar microstrip patches is presented. It has been designed, fabricated and tested to be used as the base station antenna of a mobile communication system at 2 GHz. An adequate coverage of an elongated rectangular cell is provided

A. Armogida; C. Peixeiro

1997-01-01

367

Base-station tracking in mobile communications using a switched parasitic antenna array  

Microsoft Academic Search

Base-station tracking in mobile communications benefits from a directional antenna and so requires direction finding technology. A novel technique for electronically directing the radiation pattern of an antenna array employs a directional array with only one active element and three parasitic elements operating near resonance. Three different methods of direction finding are assessed; a coarse angular location method, a precise

Stephanie L. Preston; David V. Thiel; Trevor A. Smith; S. G. O'Keefe; Jun Wei Lu

1998-01-01

368

The Magnetoelectric Dipole—A Wideband Antenna for Base Stations in Mobile Communications  

Microsoft Academic Search

In this paper, stringent requirements imposed on the design of base station antennas for mobile communications are summarized. Conventional techniques for implementing base station antennas are reviewed. The complementary antenna concept of combining an electric dipole with a magnetic dipole is reconsidered. Recently, this kind of antenna has been commonly called a “Huygen's source.” The purpose is to develop wideband

Kwai-Man Luk; Biqun Wu

2012-01-01

369

The Future Generations of Mobile Communications Based on Broadband Access Methods  

Microsoft Academic Search

The forthcoming mobile communication systems are expected to provide much variety of services from high quality voice to high definition videos through high data rate wireless channels at anywhere in the world. High data rate requires broad frequency bands, and sufficient broadband can be achieved in higher frequency bands such as microwave, Ka-band and millimeter-wave. Broadband wireless channels have to

Shingo Ohmori; Yasushi Yamao; Nobuo Nakajima

2001-01-01

370

Field strength prediction by ray-tracing for adaptive base station positioning in mobile communication networks  

Microsoft Academic Search

The Adaptive Base Station Positioning Algorithm (ABPA) is presented, which is based on a neural net approximation of the trac density in the coverage area of a cellular mobile communication system. ABPA employs simulated annealing, thereby achieving quasi-optimal base station locations depending on the topography of the investigated area. Furthermore, ABPA considers the radio wave propagation within this area for

Fritsch K. Tutschku; K. Leibnitz

1995-01-01

371

Downlink channel modeling for mobile communications with smart antennas at the base station  

Microsoft Academic Search

In this paper, an approach is presented to enable down-link channel modeling for mobile communication systems with smart antennas at the base station (BS). Based on the assumption that the angle of departure (AOD) at the BS is uniformly distributed, closed-form expressions are provided for the probability density function (PDF) of the azimuth angle of arrival (AOA), power spectral density

Qi Yao; Matthias Patzold

2003-01-01

372

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

Microsoft Academic Search

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

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

2006-01-01

373

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

374

Intercarrier interference self-cancellation scheme for OFDM mobile communication systems  

Microsoft Academic Search

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

Yuping Zhao; Sven-Gustav Häggman

2001-01-01

375

Channel Assignment and Reassignment Using Co-channel Cells in Mobile Communication Networks  

Microsoft Academic Search

The channel assignment problem arises in a mobile communication network whenever there is an installation of a new base station or one cell is split into two or more cells or power of the base station is changed. Channel assignment or reassignment is an NP-hard problem and generally a heuristic approach is used for solving large sized problems. We have

Siba K. Udgata; Shobhit Srivastava; Hitesh Mahajan; Gauri K. Udgata

2008-01-01

376

The 2 GHz high temperature superconducting receiver equipment for mobile communications  

Microsoft Academic Search

An ultra low noise and highly selective, experimental 2 GHz band cryogenic receiver front end (CRFE) has been newly developed for mobile communication base stations. It utilizes a high-Q superconducting filter, a very low noise cryogenic amplifier, and a highly reliable cooler that is very compact. The equivalent noise temperature (Teq) of the CRFE is less than 50 K (0.69

K. Satoh; T. Mimura; S. Narahashi; T. Nojima

2001-01-01

377

Information Capacity of the Space Division Multiple Access Mobile Communication System  

Microsoft Academic Search

An expression for the Shannon capacity lower bound of the space division multiple access (SDMA) mobile communication channel with interference is shown. The bound is tightly approaching the Shannon capacity of the orthogonal SDMA system over Gaussian channel with no interference. The information capacity of the SDMA system with adaptive MMSE receivers is presented as well. The SDMA system with

Predrag B. Rapajic

1999-01-01

378

Research Advances on RF Technologies for 3G\\/B3G Mobile Communications  

Microsoft Academic Search

In this paper, the research progress in RF technologies for 3G and B3G mobile communication systems in the State Key Laboratory of Millimeter Waves, Southeast University, P. R. China is briefly described including the RF modules for cdma2000, WCDMA and TD-SCDMA handsets, the RF subsystems for CDMA2000, WCDMA and B3G\\/4G systems.

Wei Hong; Jianyi Zhou; Wei Jiang; Haiming Wang; Jin Liu; Xiaowei Zhu; Jianing Zhao; Lei Zhang

2007-01-01

379

Random spacing channel assignment to reduce the nonlinear intermodulation distortion in cellular mobile communications  

Microsoft Academic Search

In cellular mobile communications, only a subset of all available frequency channels are assigned to each cell, hence, the interchannel spacing of channels is wider than the required minimum. In this paper, a random spacing channel assignment (RSCA) scheme is proposed which exploits the wider interchannel spacing of assigned channels in each cell to reduce the most deleterious third-order intermodulation

Hanwook Jung; Ozan K. Tonguz

1999-01-01

380

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

381

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

382

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

383

Digitally programmable RF front-ends: towards universal mobile communication service  

Microsoft Academic Search

Summary form only given. This presentation discusses the evolution of the wireless industry and focuses on transceiver architectures and circuit design techniques used in modern cost effective mobile communication systems. Architectures and design techniques suitable for multi-standard, low power transceivers achieving higher levels of integration are presented. The techniques exploit recent developments in submicron BiCMOS and CMOS VLSI techniques together

M. Ismail

2000-01-01

384

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

385

User and Concept Studies as Tools in Developing Mobile Communication Services for the Elderly  

Microsoft Academic Search

The basis of this study was the ageing of the population all over the world. The study concentrated on finding out the key service needs of elderly people. The service needs from the end users’ as well as the experts’ perspective were gathered by means of various group methods such ideation sessions. Four mobile communication service concepts were created using

M. Mikkonen; S. Väyrynen

2002-01-01

386

A mobile ad-hoc satellite and wireless Mesh networking approach for Public Safety communications  

Microsoft Academic Search

It is widely recognized that emergency management and disaster recovery systems are an issue of paramount importance in communities through the world. The definition of a public safety communications infrastructure is a high-priority task due to the lack of interoperability between emergency response departments, the reduced mobility during coordinated operations on a broad scale and the need for access to

G. Iapichino; C. Bonnet; O. del Rio Herrero; C. Baudoin; I. Buret

2008-01-01

387

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

388

Evolutionary simulation of an agent based mobility system using indirect communication  

Microsoft Academic Search

We study the evolutionary dynamics of a mobility system in which agents are able to explore the environ- ment and to communicate between them in order to increase the eciency of the system, i.e. to minimize the average time needed to reach their goal, choosing the quickest path and avoiding the formation of trac jams. The agents use an evolvable

Francesco Zanlungo

389

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

390

A frame synchronization method for underwater acoustic communication on mobile platform  

Microsoft Academic Search

In this paper, we propose a frame synchronization method for underwater acoustic communication on mobile platform. This new method involves transmitting signal based on hyperbolic frequency modulated (HFM) signal as a preamble of the frame, while the receiver uses a correlator which is matched to the transmitted signal. This method can provide us with good signal detection ability which is

Feng Wei; Xu Xiaomei; Zhang Lan; Chen Yougan

2010-01-01

391

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

Microsoft Academic Search

Two satellite position reporting has been introduced into the OmniTRACS mobile satellite communication system. This system significantly improves position reporting reliability and accuracy while simplifying the terminal's hardware. The positioning technique uses the original OmniTRACS TDMA timing signal formats in the forward and return link directions plus an auxiliary, low power forward link signal through a second satellite to derive

William G. Ames

1990-01-01

392

Exploring the Potential of Mobile Services to Support Learning and Communication in University Classes  

Microsoft Academic Search

This paper presents initial results of our on-going activities regarding the use of smart phones and mobile services in university classrooms at Vaxjo University. The purpose of these trials was to explore and identify which content and services could be delivered to the smart phones in order to support learning and communication in the context of university studies. The activities

Marcelo Milrad; Daniel Bergman; Michele H. Jackson

2005-01-01

393

Design, implementation, and use of a real-time distributed simulation testbed for mobile communication networks  

Microsoft Academic Search

There is a need to design, develop, and test new mobile communication networks for military applications. The hardware cost to outfit a single node may be quite high. Much of the cost is in rf hardware, modems, and encryption devices. Replicating such costs over several nodes and adding the cost of maintaining a field site can quickly lead to unacceptable

Dennis J. Baker

1997-01-01

394

Design, implementation, and use of a real-time distributed simulation testbed for mobile communication networks  

NASA Astrophysics Data System (ADS)

There is a need to design, develop, and test new mobile communication networks for military applications. The hardware cost to outfit a single node may be quite high. Much of the cost is in rf hardware, modems, and encryption devices. Replicating such costs over several nodes and adding the cost of maintaining a field site can quickly lead to unacceptable budget levels. One solution to this problem is, in the initial development and testing phase, to develop network communication systems that can operate with either real or simulated transmitters, receivers, modems, etc. This paper describes how we accomplished this task for the development of a high frequency, data/voice (D/V) mobile network. The underlying, distributed, real-time simulation software evolved from Sim++2. On top of this we built a simulation package to model mobile communication networks. Software for the SubNet Controller (SNC) of the hf D/V Network was developed to work with these simulation packages as well as to work with real rf equipment. The SNC software was tested in a 6-node network in which some of the rf equipment was simulated and some was real. The resultant system provides a testbed for examining the performance of command and control systems that must operate over mobile rf communication systems.

Baker, Dennis J.

1997-06-01

395

A simple and cheap end-to-end voice encryption framework over GSM-based networks  

Microsoft Academic Search

This paper presents a framework for voice encryption over GSM-based networks. To evaluate the framework, we have designed and implemented prototypes. The prototypes support full-duplex communication and real-time communication. To make the prototypes cheap and simple, the RC4 algorithm is utilized to protect digital of voice. The Bluetooth technology is utilized to communicate between the voice encryption prototype and a

Prawit Chumchu; Attaphon Phayak; Prakaidao Dokpikul

2012-01-01

396

Impersonation Attacks on a Mobile Security Protocol for End-to-End Communications  

NASA Astrophysics Data System (ADS)

This paper presents an analysis of a cryptographic security protocol that is designed for use in a mobile communication environment. The goal of the analysed protocol is to ensure secure end-to-end communication between two mobile users that are connected to different base stations. The analysis reveals a serious flaw in the used signature scheme of the security protocol. Exploitation of this flaw enables an intruder to use algebraic simplifications to forge signatures on arbitrary messages. Two attacks, which exploit this weakness, are detailed showing the impersonation of a mobile user and a base station, respectively. Corrections to the flawed protocol are proposed and analysed. It is established that the corrected protocol is secure against the presented attacks.

Dojen, Reiner; Pasca, Vladimir; Coffey, Tom

397

Contrast research of CDMA and GSM network optimization  

NASA Astrophysics Data System (ADS)

With the development of mobile telecommunication network, users of CDMA advanced their request of network service quality. While the operators also change their network management object from signal coverage to performance improvement. In that case, reasonably layout & optimization of mobile telecommunication network, reasonably configuration of network resource, improvement of the service quality, and increase the enterprise's core competition ability, all those have been concerned by the operator companies. This paper firstly looked into the flow of CDMA network optimization. Then it dissertated to some keystones in the CDMA network optimization, like PN code assignment, calculation of soft handover, etc. As GSM is also the similar cellular mobile telecommunication system like CDMA, so this paper also made a contrast research of CDMA and GSM network optimization in details, including the similarity and the different. In conclusion, network optimization is a long time job; it will run through the whole process of network construct. By the adjustment of network hardware (like BTS equipments, RF systems, etc.) and network software (like parameter optimized, configuration optimized, capacity optimized, etc.), network optimization work can improve the performance and service quality of the network.

Wu, Yanwen; Liu, Zehong; Zhou, Guangyue

2004-03-01

398

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

399

A parametric approach for low energy wireless data communication [mobile multimedia computing\\/communication applications  

Microsoft Academic Search

In this paper, a joint control methodology of error protection capability and modulation strategy is presented to minimize the energy dissipation of a given communication. The communication energy includes the energy consumption of the underlying digital (channel encoder\\/decoder) and analog blocks including the RF amplifier. The energy dissipation of these blocks is determined by the system configuration parameters like channel

Hunsoo Choo; Kaushik Roy

2004-01-01

400

An approach to dyadic communication in historical social movements: Dyadic communication in Maoist insurgent mobilization  

Microsoft Academic Search

The paucity of word?by?word transcriptions of movements' dyadic interactions need not completely preclude investigation of historical movements’ dyadic communication. Scholars can study the constraints that urged a movement to select dyadic communication and the general strategies used in movement dyads. Three kinds of data can be used to reconstruct general strategies used in dyads: (1) the theoretical writings of movement

J. F. Walsh Jr

1986-01-01

401

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

402

Measurement-Based Replanning of GSM Cell Capacities Considering Retrials, Redials and Hand-offs  

Microsoft Academic Search

During the optimization of a Global System for Mo- bile Communications (GSM) network, the operations and mainte- nance center (OMC) measurements are of significant importance. Because of false predictions, the capacity planning of a cell may be done inaccurately. If the capacity of the cell is not adequate to handle all of the busy-hour requests, the requests are not granted

Ertan Onur; Hakan Delic; Cem Ersoy; M. Ufuk Caglayan

403

Prospects of satellite communications for mobiles: Towards a global mobile space segment  

NASA Astrophysics Data System (ADS)

Terrestrial, maritime, and air transportation applications of communications satellites are considered. Communicating with long distance trucks can be achieved by text transmission which is cheaper than voice links, avoids access problems, and uses the frequency spectrum more efficiently. The need to accept fast and slow air traffic in the same air space, especially near airports, creates safety problems that can be overcome by equipping aircraft with a satellite controlled display device, showing traffic in the vicinity. The maritime satellite service is characterized by low market penetration that can be improved by cutting equipment costs, e.g., by decreasing ship antenna performance and using high gain satellite antennas, producing narrow beams.

Rosetti, C.

1981-11-01

404

Technological Model of the Independent Power Supply with Converters of Renewable Energy for Base Station of Mobile Communication  

Microsoft Academic Search

In Uzbekistan is present very much of items, which compactly dispersed near to underground water wells and the mountain rivers, deprived of the centralized power supply and network of communication. The basic activity of the inhabitants of these areas is the farm and for its development wireless mobile communication could be in perspective to replace telephone communication. But the embrace

B. M. Makhkamdjanov

2006-01-01

405

Voice over IP: how computing technology is being used in mobile communications.  

PubMed

This article explains how computing technology was used to address the need for mobile communications among nursing staff. In 2004, nursing staff at Fauquier Hospital relocated from one nursing floor in an older building to two floors in a new structure. This resulted in complaints and supervision issues as nursing managers, who had previously been relatively sedentary, now became quite mobile as they attempted to control nursing operations on two separate floors. Complaints arose from several sources. Nursing staff and managers both complained about the increased difficulty in communicating with each other Physicians expressed frustration to hospital administration at playing "telephone tag" with managers. The solution involved Internet Protocol technology that is in widespread use on most computer networks. The article details how this technology was selected over several other communications technologies and used to implement wireless telephony over the hospital's existing computer network. It reviews key standards and technologies and issues surrounding their use. Finally, the article demonstrates how this computing technology improved patient care by facilitating mobile communications. PMID:16266029

Johnson, William

2005-01-01

406

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

NASA Astrophysics Data System (ADS)

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

Aras, Caglan Mehmet

1993-12-01

407

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

NASA Astrophysics Data System (ADS)

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

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

408

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

409

Experimental demonstration of a retro-reflective laser communication link on a mobile platform  

NASA Astrophysics Data System (ADS)

Successful pointing, acquisition, and tracking (PAT) are crucial for the implementation of laser communication links between ground and aerial vehicles. This technology has advantages over the traditional radio frequency communication, thus justifying the research efforts presented in this paper. The authors have been successful in the development of a high precision, agile, digitally controlled two-degree-of-freedom electromechanical system for positioning of optical instruments, cameras, telescopes, and communication lasers. The centerpiece of this system is a robotic manipulator capable of singularity-free operation throughout the full hemisphere range of yaw/pitch motion. The availability of efficient two-degree-of-freedom positioning facilitated the development of an optical platform stabilization system capable of rejecting resident vibrations with the angular and frequency range consistent with those caused by a ground vehicle moving on a rough terrain. This technology is being utilized for the development of a duplex mobile PAT system demonstrator that would provide valuable feedback for the development of practical laser communication systems intended for fleets of moving ground, and possibly aerial, vehicles. In this paper, a tracking system providing optical connectivity between stationary and mobile ground platforms is described. It utilizes mechanical manipulator to perform optical platform stabilization and initial beam positioning, and optical tracking for maintaining the line-of-sight communication. Particular system components and the challenges of their integration are described. The results of field testing of the resultant system under practical conditions are presented.

Nikulin, Vladimir V.; Malowicki, John E.; Khandekar, Rahul M.; Skormin, Victor A.; Legare, David J.

2010-02-01

410

A maintenance scheme of communication link in mobile robot ad hoc networks based on potential field  

NASA Astrophysics Data System (ADS)

Maintaining communication link in mobile robot networks between task robots and a control center is very important in some urgent application occasions such as remote danger detections. To offer a reliable multi-hop communication link, a link maintaining scheme based on artificial potential field is presented. The scheme is achieved by a task robot and communication relay ones. The task robot performs predefined tasks, and relay ones are simple robots which form a communication relay chain. When robots move towards destination in formation, a kind of attractive force created by communication quality is added to traditional potential field, and relay robots follow the task robot and automatically stop at adequate locations to form a relay chain from the control station to the task robot. In order to increase relay usage efficiency, when some relays are replaced by other short cut relays, the redundant relays can be reused by initiating another moving toward specified location. Simulation results show that the scheme can provide a reliable multi-hop communication link, and that the communication connection can be obtained through minimal number of relays.

Jiang, Hong; Jin, WenPing; Yang, GyoYing; Li, LeiMin

2007-12-01

411

Laboratory evaluation of a channel-sensitive slotted Aloha access algorithm for land mobile satellite communications  

NASA Astrophysics Data System (ADS)

Land mobile satellite communication is handicapped by fading and shadowing effects in zones with low elevation angles. Slotted Aloha is a relatively simple and attractive random access scheme for such applications, since its performance does not degrade as fast as that of other schemes. A slotted Aloha based modified channel access strategy for highly unreliable channels which requires all mobile stations in a network to estimate the link quality before starting their transmission is presented. This improved slotted Aloha with channel sensing, requiring little more complexity, is analyzed in its dynamics under channel influence with the help of a hybrid evaluation tool. The simulation concept combines software routine and hardware communication devices and includes measured channel data. Results show the improvement of the suggested scheme in comparison to the conventional slotted Aloha.

Boettcher, Axel; Dippold, Michael; Jahn, Axel

1991-10-01

412

An advanced conceptual design study for a mobile satellite communications system  

NASA Astrophysics Data System (ADS)

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

Salmasi, A. B.

413

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

Microsoft Academic Search

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

I. O. de Vries

2008-01-01

414

CUBESAT-TO-GROUND COMMUNICATION AND MOBILE MODULAR GROUND STATION DEVELOPMENT  

Microsoft Academic Search

A mobile modular ground station is described for direct communication and tracking of CubeSats from various locations. The ground station operates in the UHF range and employs a circularly polarized Yagi-Uda antenna. A two-piece wooden antenna base with a telescoping mast was constructed for mounting the antenna. For an orbit height of 600 km, satellite transmit power of 27.0 dBm,

Dylan Ichikawa

415

Jitter Effect on a Digital IF Transceiver for SDR-based Mobile communication Base Station  

Microsoft Academic Search

This paper outlines the time jitter effect of a sampling clock on a Software Defined Radio (SDR) technology- based-Digital Intermediate Frequency (IF) transceiver for a mobile communication base station. The implemented Digital IF transceiver is reconfigurable to three bandwidth profiles : 1.75 MHz, 3.5 MHz, and 7 MHz each incorporating the IEEE 802.16d Worldwide Interoperability for Microwave Access (WiMAX) standard

Bong-Guk Yu; Gweon-Do Jo; Jin-Up Kim; Sung Woong Ra

2007-01-01

416

A Mobile Communication Base Station Antenna Using a Genetic Algorithm Based Fabry-Pérot Resonance Optimization  

Microsoft Academic Search

We proposed a high-gain wideband resonant-type mobile communication base station antenna using a Fabry-Pérot cavity (FPC) technique. To overcome inherent narrow radiation bandwidth of FPC-type antennas while keeping relatively high gain, we introduced a new superstrate structure composed of square patches and loops, which satisfies an FPC resonance condition at a target frequency region. To do that, we optimized the

Dongho Kim; Jeongho Ju; Jaeick Choi

2012-01-01

417

The future generations of mobile communications based on broadband access technologies  

Microsoft Academic Search

The forthcoming mobile communication systems are expected to provide a wide variety of services, from high-quality voice to high-definition videos, through high data rate wireless channels anywhere in the world. The high data rate requires broad frequency bands, and sufficient broadband can be achieved in higher frequency bands such as microwave, Ka-band, and millimeter-wave. Broadband wireless channels have to be

Shingo Ohmori; Yasushi Yamao; Nobuo Nakajima

2000-01-01

418

A dedicated mobile communication system with no base station using frequency hopping spread spectrum multiple access  

Microsoft Academic Search

The realization of an FH-SSMA (frequency-hopping spread-spectrum multiple-access) communication system useful for 16 mobile subscribers within an area of 5 miles diameter is considered. The subscriber's information is digitized with the help of a CVSD (continuously variable slope detector) codec at the rate of 16 kb\\/s which is sent through a 4\\/16 orthogonal encoder giving coded data of rate 64

R. G. Madhusudhana

1989-01-01

419

A type of base-station antennas used in MIMO mobile communication systems  

Microsoft Academic Search

MIMO (multiple-input multiple-output) systems have been widely used in the new generation mobile communications because of their large capability, high speed and low code errors. Transmitting and receiving antenna systems are the very important parts of the whole systems. And their designs will directly affect MIMO system's performance. In this paper, a type of printed-dipole antennas is introduced. The theoretical

Jinyan Li; Zaiping Nie; Yan Cheng; Musheng Liang

2006-01-01

420

A flexible and high performance cellular mobile communications system based on Orthogonal Multi-Carrier SSMA  

Microsoft Academic Search

The conventional Direct-Sequence Spread-Spectrum-Multiple-Access (DS-SSMA) system with RAKE-receiver is an interesting approach in mobile communications in order to combat the frequency selectivity of the channel. The main advantages of DS-SSMA are well known, but its capacity is limited by other-user interference. Another interesting SSMA technique that combats the frequency selectivity of the channel and achieves high spectral efficiency is based

K. Fazel; S. Kaiser; M. Schnell

1995-01-01

421

A demonstration HTS base station sub-system for mobile communications  

Microsoft Academic Search

A demonstration sub-system for mobile communications was developed. In this system, a high-temperature superconducting (HTS) microstrip bandpass filter on r-plane sapphire substrate was designed to have a quasi-elliptic function response, which was aimed at covering the whole receive band of DCS 1800 base station, i.e. 1710-1785 MHz. This filter was then integrated with a low noise amplifier (LNA) and a

Hong Li; Yusheng He; Aisheng He; Shunzhou Li; Chunguang Li; Lingwen Yan; Jingtao Liang; Wenxiu Zhu; Yuan Zhou; Jiasheng Hong; M. J. Lancaster

2002-01-01

422

Reduced complexity comb-filters for decimation and interpolation in mobile communications terminals  

Microsoft Academic Search

In mobile communications systems complexity and efficiency are issues of paramount importance. Therefore when implementing integer factor sample-rate conversion, comb-filters-especially cascaded-integrator-comb (CIC) filters-are a good choice of realizing linear-phase filters with low complexity. However, neither the direct implementation of comb-filters as transversal filters nor their implementation as CIC-filters are minimal realizations. Since both, decimators and interpolators are time-variant systems, the

Tim Hentschel; Gerhard Fettweis

1999-01-01

423

Blind array channel division multiple access (AChDMA) for mobile communications  

Microsoft Academic Search

The paper introduces array channel division multiple access (AChDMA), which is a new blind algorithm for advanced SDMA in mobile communications systems. As an SDMA technique, AChDMA increases the system capacity by improving its time and frequency reuse. Being a blind algorithm, it requires no training sequences, previously known directions of arrival, or user codes, AChDMA separates the moving sources

Victor A. N. Barroso; J. M. F. Moura; J. Xavier

1998-01-01

424

Design of a simple antenna for mobile communications in the L-band  

Microsoft Academic Search

It is expected that second-generation mobile-communications in the L-band will be introduced to the market in the immediate future. A cellular system of mini- or micro-cells will be used to relieve the traffic congestion. Similar to the CT-2 system currently used in Hong Kong and Singapore, the new system will encompass thousands or tens of thousands of micro-cells inter-connected by

R. S. K. Wong; E. K. N. Yung

1994-01-01

425

Power resource cooperation control considering wireless QoS for CDMA packet mobile communication systems  

Microsoft Academic Search

With the rapidly increasing demand for high-speed mobile multimedia and the need to support diversified requirements of users by packet communication systems, wireless quality of service (QoS) resource management becomes more and more indispensable, especially for the IMT-2000 system and beyond. In previous researches, QoS controls carried out independently at base stations have been proposed. However, in a CDMA packet

Lan Chen; Hidetoshi Kayama; Narumi Umeda

2002-01-01

426

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

Microsoft Academic Search

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

Albrecht Fehske; Gerhard Fettweis; Jens Malmodin; Gergely Biczok

2011-01-01

427

Experiment Plan of ETS8 in Orbit : Mobile Communications and Navigation  

Microsoft Academic Search

The experiment of S-Band Mobile Communications\\/Broadcasting and L\\/S-Band Satellite Navigation is the main objectives of Engineering Test Satellite - 8 (ETS-8), which will be launched in 2004 into geostationary orbit at 146 degree East. In this paper, the basic experiment plan is described. After the function tests of satellite in orbit, participation of those who have interest in this experiment

M. Homma; S. Hama; H. Kohata

2002-01-01

428

Propagation characteristics for wideband outdoor mobile communications at 5.3 GHz  

Microsoft Academic Search

In this paper, empirical channel models and parameters are derived from the wideband measured data at 5.3 GHz in outdoor mobile communications. The path loss exponents and intercepts are obtained by using the least square method. The mean excess delay and mean root-mean-square (rms) delay spread are within 29-102 ns and 22-88 ns, respectively. The correlation distances and bandwidths are

Xiongwen Zhao; Jarmo Kivinen; Pertti Vainikainen; Kari Skog

2002-01-01

429

Use of Dempster-Shafer Theory and Bayesian Inferencing for Fraud Detection in Mobile Communication Networks  

Microsoft Academic Search

This paper introduces a framework for fraud detection in mobile communication networks based on the current as well as past\\u000a behavioral pattern of subscribers. The proposed fraud detection system (FDS) consists of four components, namely, rule-based\\u000a deviation detector, Dempster-Shafer component, call history database and Bayesian learning. In the rule-based component, we\\u000a determine the suspicion level of each incoming call based

Suvasini Panigrahi; Amlan Kundu; Shamik Sural; Arun K. Majumdar

2007-01-01

430

On the development of superconducting microstrip filters for mobile communications applications  

Microsoft Academic Search

This paper presents recent developments of an eight-pole planar high-temperature superconducting (HTS) bandpass filter with a quasi-elliptic function response. A novel planar filter configuration that allows a pair of transmission zeros to be placed at the band edges is described. The miniature HTS filter has a fraction bandwidth less than 1% and is designed for mobile communication base-station applications to

Jia-Sheng Hong; Michael J. Lancaster; Dieter Jedamzik; Robert B. Greed

1999-01-01

431

DSD (Double Soft Decision) Concatenated FEC Scheme in Mobile Satellite Communication Systems  

Microsoft Academic Search

In order to realize a higher-code-gain forward error correction scheme in mobile satellite communication systems, a novel concatenated coding scheme employing soft decision decoding for not only inner codes but also outer codes (double soft decision, or DSD, concatenated forward error correction scheme) is proposed. Soft-decision outer decoding can improve the bit error probability of inner decoded data. In this

Shunji Honda; Shuji Kubota; Shuzo Kato

1992-01-01

432

A 60 GHz Radio-Over-Fiber Network Architecture for Seamless Communication With High Mobility  

Microsoft Academic Search

We demonstrate a 60 GHz broadband picocellular Radio-over-Fiber network architecture that enables seamless connectivity for highly mobile end-users. Its seamless communication capabilities arise by the supported handover scheme that relies on a novel Moving Extended Cell (MEC) concept. MEC exploits user-centric virtual groups of adjacent cells that transmit the same data content to the user and utilizes a switch mechanism

Nikos Pleros; Konstantinos Vyrsokinos; Kostas Tsagkaris; Nikolaos D. Tselikas

2009-01-01

433

On the performance of HTS microstrip quasi-elliptic function filters for mobile communications application  

Microsoft Academic Search

The low-loss and high-selective high-temperature superconducting (HTS) bandpass filters can enhance performance of mobile communications systems. In this paper, we summarize a recent progress of novel HTS preselect bandpass filters that have been developed for a European research project. The objective of the project is to construct an HTS-based transceiver for mast-mounted DCS1800 base stations. The HTS preselect receive filters

Jia-Sheng Hong; Michael J. Lancaster; Dieter Jedamzik; Robert B. Greed; Jean-Claude Mage

2000-01-01

434

Definition of a commercial mobile satellite services network to meet DoD communications needs  

Microsoft Academic Search

Commercial-based satellite networks have the potential to provide cost effective communications support for the Department of Defense (DoD's) less critical needs which include administration, logistics, and other support functions. This paper summarizes the definition of a possible multi-vendor Mobile Satellite Services (MSS) network architecture. A determination is presented as to what degree existing and planned commercial MSS systems could satisfy

K. M. Price; R. G. Leamon

1993-01-01

435

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

Microsoft Academic Search

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

Filippo Giannetti; Marco Luise; Ruggero Reggiannini

1999-01-01

436

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

NASA Astrophysics Data System (ADS)

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

Ames, William G.

437

Broadband and scalable mobile satellite communication system for future access networks  

NASA Astrophysics Data System (ADS)

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

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

2005-07-01

438

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

NASA Astrophysics Data System (ADS)

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

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

1980-07-01

439

A Study on the Cell Sectorization Using the Wide-beam and Narrow-beam for CDMA Mobile Communication Systems  

Microsoft Academic Search

Cell sectorization and improvement of the Ec\\/Io are technologies to offer good quality of services (QoS) and coverage for new and sophisticated power control to achieve high capacity in CDMA cellular mobile communication networks. In this paper, in order to efficient cell sector and to improve the Ec\\/Io of the pilot channel in CDMA mobile communication systems, I analyze and

Dong You Choi; Jung Jin Park

2007-01-01

440

Mobile Communication and Civil Society: Linking Patterns and Places of Use to Engagement with Others in Public  

ERIC Educational Resources Information Center

|This study examined whether and how mobile communication influences the extent to which one engages with new people in public settings. Contrary to our expectation, general use of the technology in public did not detract from conversing with strangers. Shifting focus from "where" one uses the mobile phone to "how" it is used, we found that uses…

Campbell, Scott W.; Kwak, Nojin

2011-01-01

441

The Mobil Integrated C{sup 3} (command control and communications) and Security System  

SciTech Connect

The current political and economic situations suggest that significant reductions of nuclear forces outside the US will continue. This implies that in times of crisis the rapid deployment of nuclear weapons into a theater may be required. This paper describes a proposed Mobile Integrated C{sup 3} and Security System (MICSS). The MICSS, together with associated personnel, could satisfy the command and control and security requirements of a deployed nuclear operation. Rapid deployment poses unique nuclear weapon surety difficulties that must be overcome for the operation to be effective and survivable. The MICSS must be portable, reliable, limited in size, and easily emplaced to facilitate movement, reduce the possibility of detection, and minimize manpower requirements. The MICSS will be based on existing technology. Sandia has designed prototype mobile command centers for the military. These command centers are based on an approach that stresses modularity, standards, and the use of an open architecture. Radio, telephone, satellite communications, communication security, and global positioning system equipment has been successfully integrated into the command centers. Sandia is also supporting the development of portable security systems for the military. These systems are rapidly deployable and mission flexible and are capable of intrusion detection, area and alarm display, night assessment, and wireless sensor communications. This paper is organized as follows: Background information about the prototype mobile command centers will be presented first. Background information about portable security systems concepts will then be given. Next, an integrated communications and security system will be presented, and finally, the design and status of a prototype MICSS will be described.

Eras, A.; Brown, R.D.

1993-06-15

442

An overview of the OmniTRACS - The first operational two-way mobile Ku-band satellite communications system  

NASA Astrophysics Data System (ADS)

A two-way mobile Ku-band satellite-based communications system is presented, which has a position reporting capability integrated into a mobile terminal, allowing automatic transmission of LORAN-C derived position information. The system and its service capabilities are described, including the mobile satellite terminal and network management facility. The possible applications of the system are outlined, including applications in transportation, vehicle location, public safety, and public utilities.

Jacobs, Irwin M.

1989-12-01

443

[Mobile hospital -real time mobile telehealthcare system with ultrasound and CT van using high-speed satellite communication-].  

PubMed

A real-time telescreening system is developed to detect early diseases for rural area residents using two types of mobile vans with a portable satellite station. The system consists of a satellite communication system with 1.5Mbps of the JCSAT-1B satellite, a spiral CT van, an ultrasound imaging van with two video conference system, a DICOM server and a multicast communication unit. The video image and examination image data are transmitted from the van to hospitals and the university simultaneously. Physician in the hospital observes and interprets exam images from the van and watches the video images of the position of ultrasound transducer on screenee in the van. After the observation images, physician explains a results of the examination by the video conference system. Seventy lung CT screening and 203 ultrasound screening were done from March to June 2002. The trial of this real time screening suggested that rural residents are given better healthcare without visit to the hospital. And it will open the gateway to reduce the medical cost and medical divide between city area and rural area. PMID:12832865

Takizawa, Masaomi; Miyashita, Toyohisa; Murase, Sumio; Kanda, Hirohito; Karaki, Yoshiaki; Yagi, Kazuo; Ohue, Toru

2003-01-01

444

A Harmonic Approach to Data Transmission over GSM Voice Channel  

Microsoft Academic Search

One of the most important objectives in mobile communication systems is secure data communication (including text, picture, video and voice) especially, in high bit rate. For this reason, in this paper, a new procedure is proposed in which the intended data or voice is modulated onto speech-like waveforms; Then the modulated waveforms are transmitted over the global system for mobile

Mahsa Rashidi; Abolghasem Sayadiyan; Pejman Mowlaee

2008-01-01

445

A feasibility study of a mobile communication network using a constellation of low earth orbit satellites  

NASA Astrophysics Data System (ADS)

An effort was made to study whether the increased survivability, true global coverage, and reduced path loss of a LEO network could be utilized to give a viable mobile communication system. The architecture of such a network is complex, but it is expected that the use of advanced technology can overcome most limitations. An optimum constellation is considered, and the first three layers of a digital network are examined. Under certain simplifying assumptions it is shown that the proposed configuration is viable and compares favorably with a similar geostationary network with regards to the overall space-segment cost. The cost benefit begins to favor the LEONET for simpler spacecraft. It is also noted that it may be possible to scale down the LEO constellation to a smaller size so as to provide continuous coverage above about 70 deg latitude, where geostationary satellites are ineffective. This hybrid architecture is also likely to minimize interference with geostationary satellite systems in the congested mobile bands.

Richharia, M.; Hansel, P. H.; Bousquet, P. W.; O'Donnell, M.

446

The effect of GSM-like ELF radiation on the alpha band of the human resting EEG  

Microsoft Academic Search

Mobile phone handsets such as those operating in the GSM network emit extremely low frequency electromagnetic fields ranging from DC to at least 40 kHz. As a subpart of an extended protocol, the influence of these fields on the human resting EEG has been investigated in a fully counter balanced, double blind, cross-over design study that recruited 72 healthy volunteers.

Nicholas Perentos; Rodney J. Croft; Raymond J. McKenzie; Dean Cvetkovic; Irena Cosic

2010-01-01

447

Modeling human dialogue-the case of group communications in trunked mobile telephony  

NASA Astrophysics Data System (ADS)

In this report we study the dynamics characteristics of conversations among several participants, analyzing trunked mobile telephony databases. We find that the duration of the dialogue sessions deviates systematically from the predictions of Poisson statistics, following probability distributions with either log-normal or power law tail. We propose that such a behavior can be described using the Bouchaud-Mezard (B-M) stochastic model, which suggests that the two probability distributions correspond to different types of human networking in conversations. We discuss the implications of our results in risk assessment in communications.

Xenikos, D. G.

2009-12-01

448

A 3 V MMIC chip set for 1.9 GHz mobile communication systems  

Microsoft Academic Search

A MMIC chip-set for 1.9 GHz mobile communication systems consists of a single-pole double-throw (SPDT) switch, a fully-integrated power amplifier, a low-noise amplifier integrated with an auto-gain-control (AGC) amplifier and an up-converter that is integrated on the same chip with a down-converter. All four chips operate at a 3±0.2 V power supply and are fabricated using an ion-implanted GaAs MESFET

S. Tanaka; E. Hase; A. Nakajima; K. Sugano; T. Fujioka; Y. Imakado; K. Fujiwara; T. Okamoto; Y. Shigeno; K. Sato; I. Arai; M. Yamane; C. Kusano; K. Sakamoto; J. Nakagawa; M. Koya

1995-01-01

449

Effect of a chronic GSM 900 MHz exposure on glia in the rat brain.  

PubMed

Extension of the mobile phone technology raises concern about the health effects of 900 MHz microwaves on the central nervous system (CNS). In this study we measured GFAP expression using immunocytochemistry method, to evaluate glial evolution 10 days after a chronic exposure (5 days a week for 24 weeks) to GSM signal for 45 min/day at a brain-averaged specific absorption rate (SAR)=1.5 W/kg and for 15 min/day at a SAR=6 W/kg in the following rat brain areas: prefrontal cortex (PfCx), caudate putamen (Cpu), lateral globus pallidus of striatum (LGP), dentate gyrus of hippocampus (DG) and cerebellum cortex (CCx). In comparison to sham or cage control animals, rats exposed to chronic GSM signal at 6 W/kg have increased GFAP stained surface areas in the brain (p<0.05). But the chronic exposure to GSM at 1.5 W/kg did not increase GFAP expression. Our results indicated that chronic exposure to GSM 900 MHz microwaves (SAR=6 W/kg) may induce persistent astroglia activation in the rat brain (sign of a potential gliosis). PMID:18424058

Ammari, Mohamed; Brillaud, Elsa; Gamez, Christelle; Lecomte, Anthony; Sakly, Mohsen; Abdelmelek, Hafedh; de Seze, René

2008-03-26

450

TCP/IP Performance Evaluations Based on Elevation Angles for Mobile Communications Employing Stratospheric Platform  

NASA Astrophysics Data System (ADS)

This paper describes a proposed propagation estimation method and TCP/IP-based evaluations for mobile communications employing a stratospheric platform. To estimate a wireless channel, a realistic and detailed description of its physical environment must be accurately defined. Therefore, a building distribution model characterizing the physical environment in areas in Japan is presented. The analyses of the propagation estimation method are based on the “ray-tracing” model. The results from the proposed method are derived depending on elevation and azimuth angles. In order to validate our results, comparisons between the proposed method and our previous measurement are made for a typical semi-urban area in Japan. The comparisons show close agreement between the estimation results and the measurement results. Finally and interestingly, we present communication performance evaluations based on TCP/IP protocol by using the results achieved from our channel estimation with semi-analytical and simulation approach.

Kong, Marry; Yorkinov, Otabek; Shimamoto, Shigeru

451

Using a Communication Model to Collect Measurement Data through Mobile Devices  

PubMed Central

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

Bravo, Jose; Villarreal, Vladimir; Hervas, Ramon; Urzaiz, Gabriel

2012-01-01

452

Studies on tumor incidence in mice exposed to GSM cell-phone radiation [Health Effects  

Microsoft Academic Search

This paper studies on tumor incidence in mice exposed to GSM cell-phone radiation. The first study of lymphomas in female Emu_Pim1 transgenic mice using frequencies and modulations specific to cellular mobile phones was conducted in Australia in which the incidence was shown to be significantly higher (odds ratio, OR = 2.4) in the exposed mice (43%) than in the sham

James C. Lin

2008-01-01

453

Proactive TCP Mechanism to Improve Handover Performance in Mobile Satellite and Terrestrial Networks  

NASA Astrophysics Data System (ADS)

Emerging standardization of Geo Mobile Radio (GMR-1) for satellite system is having strong resemblance to terrestrial GSM (Global System for Mobile communications) at the upper protocol layers and TCP (Transmission Control Protocol) is one of them. This space segment technology as well as terrestrial technology, is characterized by periodic variations in communication properties and coverage causing the termination of ongoing call as connections of Mobile Nodes (MN) alter stochastically. Although provisions are made to provide efficient communication infrastructure this hybrid space and terrestrial networks must ensure the end-to-end network performance so that MN can move seamlessly among these networks. However from connectivity point of view current TCP performance has not been engineered for mobility events in multi-radio MN. Traditionally, TCP has applied a set of congestion control algorithms (slow-start, congestion avoidance, fast retransmit, fast recovery) to probe the currently available bandwidth on the connection path. These algorithms need several round-trip times to find the correct transmission rate (i.e. congestion window), and adapt to sudden changes connectivity due to handover. While there are protocols to maintain the connection continuity on mobility events, such as Mobile IP (MIP) and Host Identity Protocol (HIP), TCP performance engineering has had less attention. TCP is implemented as a separate component in an operating system, and is therefore often unaware of the mobility events or the nature of multi-radios' communication. This paper aims to improve TCP communication performance in Mobile satellite and terrestrial networks.

Vinayakray-Jani, Preetida; Sanyal, Sugata

2012-06-01

454

Practical Context Awareness for GSM Cell Phones  

Microsoft Academic Search

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

Ian Anderson; Henk L. Muller

2006-01-01

455

Partial GSM spectrum reuse for femtocells  

Microsoft Academic Search

In this paper the feasibility of femtocells partially reusing GSM spectrum is investigated. Due to the increasing scarcity and cost of spectrum, partial spectrum reuse by secondary networks is being considered to improve spectral efficiency. Additionally, new revenue streams can be extracted from existing resources by utilising partial spectrum reuse. The partial reuse of spectrum depends largely on the ability

Joseph O'Carroll; Holger Claussen; Linda Doyle

2009-01-01

456

GSM passive radar for medium range surveillance  

Microsoft Academic Search

This paper presents a passive radar system using GSM as illuminator of opportunity. The new feature is the used high performance uniform linear antenna (ULA) for extracting both the reference and the echo signal in a software defined radar. The signal processing steps used by the proposed scheme are detailed and the feasibility of the whole system is proved by

Reda Zemmari; Ulrich Nickel; Wulf-Dieter Wirth

2009-01-01

457

Images of Men and Women in Mobile Phone Advertisements: A Content Analysis of Advertisements for Mobile Communication Systems in Selected Popular Magazines  

Microsoft Academic Search

The present study was designed to analyze gender stereotypes in print advertisements for mobile communication systems in German popular magazines intended for men, women, and general readership. Depictions of both women and men are addressed. A total of 288 depictions were examined using Goffman’s (Gender advertisements, Harvard University Press, Cambridge, Massachusetts, 1979) framework for content analysis. Other variables studied were

Nicola Döring; Sandra Pöschl

2006-01-01

458

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

NASA Astrophysics Data System (ADS)

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

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

459

Place-based attributes predict community membership in a mobile phone communication network.  

PubMed

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

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

2013-02-22

460

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

PubMed Central

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

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

2013-01-01

461

Modeling and optimization of zone-based registration considering cell-by-cell location area for mobile communication networks  

Microsoft Academic Search

Zone-based registration (ZBR) has been adopted in most mobile communication networks and there have been numerous analytical models and performance studies of ZBR. However, many previous studies in which ZBR was compared with other registration schemes utilized ring-by-ring location registration area and two-dimensional random walk mobility models. In this study we show that this approach fails to smoothly reflect ZBR’s

Kyung Hee Kim; Jang Hyun Baek; Che Soong Kim

2008-01-01

462

Mobile telecommunication: Current knowledge on risk perception and risk communication: Results gained within the German Mobile Telecommunication Research Programme  

Microsoft Academic Search

Factors influencing the public' risk perception have already been investigated since the 70s of the last century. With the increased use of mobile telecommunication and the increased public attention to potential health risks from electromagnetic fields, the risk perception and society's dealing with the topic “mobile telecommunication” came into focus. From 2002 to 2008, the German Mobile Telecommunication Research Programme

Poelzl Christiane

2011-01-01

463

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

NASA Astrophysics Data System (ADS)

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

Byun, Tae-Young

464

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

PubMed

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

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

2009-10-01

465

Identity-Based Cryptography for Securing Mobile Phone Calls  

Microsoft Academic Search

In this paper, an identity-based key agreement system for mobile telephony in GSM and UMTS networks is pre- sented. The use of telephone numbers as public keys allows the system to piggyback much of the security overhead for key management to the existing GSM or UMTS infrastruc- ture. The proposed approach offers solutions to the problems of multi-domain key generation,

Matthew Smith; Christian Schridde; Björn Agel; Bernd Freisleben

2009-01-01

466

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

NASA Astrophysics Data System (ADS)

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, or uncertainties. The systems engineering approach described here was used to mitigate these risks. The result was the development and implementation of the JPL Mobile Satellite Experiment Project. This Project included not only technology development, but also studies to support NASA in the definition of the regulatory, market, and investment environments within which LMSS would evolve and eventually operate, as well as initiatives to mitigate their associated commercialization risks. The end result of these government-led endeavors was the acceleration of the introduction of commercial mobile satellite services, both nationally and internationally.

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

1991-10-01

467

System for determining and registering location of mobile terminal for communication system with non-geosynchronous satellites  

US Patent & Trademark Office Database

A system for determining and registering the location of mobile terminals in a mobile communication system using non-geosynchrous satellites, in which each land earth station transmits its identification information via spot beams of satellites or together with identification information of a spot beam and that of satellite. A mobile terminal thus receives identification information, and transmits the received identification information together with information on time of reception and the terminal identifying information to the terrestrial network for registering the latest location information. Since the latest location information of mobile terminal is registered in the terrestrial network as mentioned above, a call can be connected to the mobile terminal simply by sending a call announcement message by referring the registered location information. This leads to reduction of the number of circuits that are needed for sending call announcement messages.

1996-08-20

468

Path Loss Prediction Formula in Urban Area for the Fourth-Generation Mobile Communication Systems  

NASA Astrophysics Data System (ADS)

A site-general type prediction formula is created based on the measurement results in an urban area in Japan assuming that the prediction frequency range required for Fourth-Generation (4G) Mobile Communication Systems is from 3 to 6GHz, the distance range is 0.1 to 3km, and the base station (BS) height range is from 10 to 100m. Based on the measurement results, the path loss (dB) is found to be proportional to the logarithm of the distance (m), the logarithm of the BS height (m), and the logarithm of the frequency (GHz). Furthermore, we examine the extension of existing formulae such as the Okumura-Hata, Walfisch-Ikegami, and Sakagami formulae for 4G systems and propose a prediction formula based on the Extended Sakagami formula.

Kitao, Koshiro; Ichitsubo, Shinichi

469

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

Code of Federal Regulations, 2010 CFR

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

2010-01-01

470

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

Code of Federal Regulations, 2010 CFR

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

2009-01-01

471

Exposure assessment of mobile phone base station radiation in an outdoor environment using sequential surrogate modeling.  

PubMed

Human exposure to background radiofrequency electromagnetic fields (RF-EMF) has been increasing with the introduction of new technologies. There is a definite need for the quantification of RF-EMF exposure but a robust exposure assessment is not yet possible, mainly due to the lack of a fast and efficient measurement procedure. In this article, a new procedure is proposed for accurately mapping the exposure to base station radiation in an outdoor environment based on surrogate modeling and sequential design, an entirely new approach in the domain of dosimetry for human RF exposure. We tested our procedure in an urban area of about 0.04?km(2) for Global System for Mobile Communications (GSM) technology at 900?MHz (GSM900) using a personal exposimeter. Fifty measurement locations were sufficient to obtain a coarse street exposure map, locating regions of high and low exposure; 70 measurement locations were sufficient to characterize the electric field distribution in the area and build an accurate predictive interpolation model. Hence, accurate GSM900 downlink outdoor exposure maps (for use in, e.g., governmental risk communication and epidemiological studies) are developed by combining the proven efficiency of sequential design with the speed of exposimeter measurements and their ease of handling. PMID:23315952

Aerts, Sam; Deschrijver, Dirk; Joseph, Wout; Verloock, Leen; Goeminne, Francis; Martens, Luc; Dhaene, Tom

2013-01-11

472

Performance Analysis of MUSIC and ESPRIT DOA Estimation Algorithms for Adaptive Array Smart Antenna in Mobile Communication  

Microsoft Academic Search

Adaptive array smart antenna involves the array processing to manipulate the signals induced on various antenna elements in such way that the main beam directing towards the desired signal and forming the nulls towards the interferers. Such smart antennas are widely used in wireless mobile communications as they can increase the channel capacity and coverage range. In adaptive array smart

T. B. Lavate; V. K. Kokate; A. M. Sapkal

2010-01-01

473

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

Microsoft Academic Search

In this paper, a procedure is proposed for generating simple and practical compliance boundaries for mobile communication base station antennas. The procedure is based on a set of formulae for estimating the specific absorption rate (SAR) in certain directions around a class of common base station antennas. The formulae, given for both whole-body and localized SAR, require as input the

B. Thors; B. Hansson; C. Törnevik

2009-01-01

474

On the Estimation of SAR and Compliance Distance Related to RF Exposure From Mobile Communication Base Station Antennas  

Microsoft Academic Search

In this paper, maximum specific absorption rate (SAR) estimation formulas for RF main beam exposure from mobile communication base station antennas are proposed. The formulas, given for both whole-body SAR and localized SAR, are heuristic in nature and valid for a class of common base station antennas. The formulas were developed based on a number of physical observations and are

B. Thors; M. L. Strydom; B. Hansson; F. Meyer; K. Karkkainen; P. Zollman; S. Ilvonen; C. Tornevik

2008-01-01

475

Informing the public about information and participation strategies in the siting of mobile communication base stations: an experimental study  

Microsoft Academic Search

Informing the public and ensuring their participation are considered important characteristics for a successful siting of mobile communication base stations. However, there is only sparse empirical evidence for this presumption. In particular, nothing is known about whether informing people that a siting decision is based on public information and participation activities has any positive effects. The experimental study presented here

Peter M. Wiedemann; Holger Schütz

2008-01-01

476

A novel channel estimation method for OFDM mobile communication systems based on pilot signals and transform-domain processing  

Microsoft Academic Search

A method of estimating the channel transfer function is presented for orthogonal frequency division multiplexing (OFDM) mobile communication systems working under time-variant radio channel conditions. The proposed method employs lowpass filtering in a transform domain so that intercarrier interference and additive white Gaussian noise components in the received pilot signals are significantly reduced. The cutoff frequency of the transform-domain filter

Yuping Zhao; Aiping Huang

1997-01-01

477

2 GHz outdoor to indoor propagation at high elevation angles for mobile communications served by high altitude platform stations  

Microsoft Academic Search

High altitude platform stations have been recently proposed as a new means of providing international mobile communications (IMT-2000). One critical issue that has not been resolved yet is the possibility of providing indoor services. This paper examines the penetration into buildings loss at high elevation angles. Two approaches are followed: An empirical model is presented and evaluated through comparison with

D. I. Axiotis; M. E. Theologou

2002-01-01

478

The emergence of new types of hybrid mobile communication environments and their impact on social life within the urban context  

Microsoft Academic Search

This paper aims at investigating the emergence of new forms of communication envi- ronments supported by the integration of new mobile and locative media technologies and the impact that the implementation of these systems may have on mediated com- munication within the urban context. The paper focuses on such systems accessed via mainly 3D interfaces and supported by different output

Dimitrios Charitos; Katerina Diamantaki; Angeliki Gazi; Michael Meimaris

479

Compatibility Analysis between Wideband Code Division Multiple Access (WCDMA) Service and Global Mobile Personal Communication by Satellite (GMPCS)  

Microsoft Academic Search

Due to explosive demand for wireless service and limited frequency spectrum resource, an efficient use of frequency spectrum has been a critical issue for making a full use of available frequency bands. In this paper, we analyze the compatibility between wideband code division multiple access (WCDMA) and the global mobile personal communication by satellite (GMPCS) which is investigated by analyzing

Yong-il Oh; Chung Sang Lyu; Seong Teak Oh; Jin Young Kim

2008-01-01

480

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

Microsoft Academic Search

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

Rafael Obregón; Silvio Waisbord

2010-01-01

481

'A New Sense of Place?' Mobile 'Wearable' Information and Communications Technology Devices and the Geographies of Urban Childhood  

Microsoft Academic Search

In this paper we describe a new research initiative, 'A New Sense of Place?', which involves the collaboration of private- and public-sector partners. Its purpose is to explore and develop the interface between children and new mobile 'wearable' computing and communication devices. The research team is particularly interested in how these new technologies might be applied to help children (re-)engage

OWAIN JONES; MORRIS WILLIAMS; CONSTANCE FLEURIOT

2003-01-01

482

The Investigation of Cloud-Computing-based Image Mining Mechanism in Mobile Communication WEB on Android  

Microsoft Academic Search

With the development of 3G network technology, the rapid upgrading of mobile phone hardware, and the refined requirements for mobile phones by mobile phone users, it is essential for mobile phones to be able to promptly and accurately process images. A mobile phone terminal sends the service requests to cloud computer system which then processes the requests and sends the

Cai-Dong Gu; Kan Lu; Jian-Ping Wu; Ying-li Fu; Jing-xiang Li; Chang-shui Xiao; Mao-xin Si; Zhao-bin Liu

2010-01-01

483

The iPad and mobile technology revolution: benefits and challenges for individuals who require augmentative and alternative communication.  

PubMed

The iPad and other mobile technologies provide powerful new tools to potentially enhance communication for individuals with developmental disabilities, acquired neurogenic disorders, and degenerative neurological conditions. These mobile technologies offer a number of potential benefits, including: (a) increased awareness and social acceptance of augmentative and alternative communication (AAC), (b) greater consumer empowerment in accessing AAC solutions, (c) increased adoption of AAC technologies, (d) greater functionality and interconnectivity, and (e) greater diffusion of AAC research and development. However, there remain a number of significant challenges that must be addressed if these benefits are to be fully realized: (a) to ensure the focus is on communication, not just technology, (b) to develop innovative models of AAC service delivery to ensure successful outcomes, (c) to ensure ease of access for all individuals who require AAC, and, (d) to maximize AAC solutions to support a wide variety of communication functions. There is an urgent need for effective collaboration among key stakeholders to support research and development activities, and to ensure the successful implementation of mobile technologies to enhance communication outcomes for individuals who require AAC and their families. PMID:23705813

McNaughton, David; Light, Janice

2013-06-01

484

Design and Implementation of Remote Monitoring System Based on GSM  

Microsoft Academic Search

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

Peijiang Chen; Xuehua Jiang

2008-01-01

485

Practical Metropolitan-Scale Positioning for GSM Phones  

Microsoft Academic Search

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

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

2006-01-01

486

GSM Evolution Importance in Re-Farming 900 MHz Band  

Microsoft Academic Search

Re-farming of 900 MHz band into HSPA has been started and is likely to happen later with LTE. Typically operators have less than 10 MHz block of 900 MHz spectrum and therefore co-existence of two systems in that band is causing challenges. One of the major issues is the high GSM voice traffic that will remain in the GSM network.

Robson D. Vieira; Rafael C. D. Paiva; Jari Hulkkonen; Rauli Jarvela; Renato F. Iida; Mikko Säily; Fernando M. Tavares; Kari Niemela

2010-01-01

487

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

NASA Astrophysics Data System (ADS)

Next-generation LEO System Research Center (NeLS) was formed in the end of 1997 as a research group under the Telecommunications Advancement Organization of Japan, in cooperation with the telecommunications operators, manufacturers, universities and governmental research organization. The aim of this project is to develop new technology for global multimedia mobile satellite communications services with a user data rate around 2Mbps for handy terminals. component of the IMT-2000, and the second generation of the big-LEO systems. In prosecuting this project, two-phase approach, phase 1 and phase 2, is considered. Phase 1 is the system definition and development of key technologies. In Phase 2, we plan to verify the developed technology in Phase 1 on space. From this year we shifted the stage to Phase 2, and are now developing the prototype of on-board communication systems for flight tests, which will be planed at around 2006. The satellite altitude is assumed to be 1200 km in order to reduce the number of satellites, to avoid the Van Allen radiation belts and to increase the minimum elevation angle. Ten of the circular orbits with 55 degree of inclination are selected to cover the earth surface from -70 to 70 degree in latitude. 12 satellites are positioned at regular intervals in each orbit. In this case, the minimum elevation angle from the user terminal can be keep more than 20 degree for the visibility of the satellite, and 15 degree for simultaneous visibility of two satellites. Then, NeLS Research Center was focusing on the development of key technologies as the phase 1 project. Four kinds of key technologies; DBF satellite antenna, optical inter-satellite link system, satellite network technology with on-board ATM switch and variable rate modulation were selected. Satellite Antenna Technology: Development of on-board direct radiating active phased array antenna with digital beam forming technology would be one of the most important breakthroughs for the satellite communication systems. Therefore, the experimental DBF network with 16 radiating elements was developed for confirming a basic signal processing performance. A/D sampled data are processed by using FPGA circuit for beam forming by real-time basis. Optical Inter-Satellite Link Technology: The inter-satellite link (ISL) technology is also important, because the inter-satellite network is essential to realize the low delay network connection for multimedia services. The optical ISL simulator was developed for the study of optical modem and optical tracking mechanism. And the sensitivity of 56 photons/bit at 10-9 of error rate has been achieved by employing the Erbium doped fiber amplifier, polarizing filter and narrow band optical filter. Coude path type, the active universal joint (AUJ) type and two flat mirror type of optical antenna mechanism were developed. Satellite Network Technology: For constructing this optical ISL ring, the utilization of wavelength division multiplexing (WDM) technology is envisaged. By applying WDM technology to the optical intra-orbital ISL, logical mesh connections can be achieved by assigning the appropriate wavelength for the links among satellites. By using inclined orbit, inter-orbital ISL connection can be keep continuously. Therefore, WDM technology is also applicable to the inter-orbital ISL network. The satellite ATM network simulator was developed in order to investigate the effect of delay fluctuation caused by the satellite constellations. This simulator works as real-time basis by using commercial ATM switches and personal computers. This simulator was installed Dijkstra's algorithm to determine satellite routing path in order to minimize the end-to-end delay time from the source terminal to the destination terminal. The satellite IP network simulator has been developed in order to evaluate the congestion of the multimedia traffic. Variable Rate Modulation Technology: Considering the propagation impairments in the mobile conditions, we employ the variable rate transmission, which maintains the communication service

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

2002-01-01

488

Interactive TV and Mobile Communications: New Dimensions for Value Added Services  

Microsoft Academic Search

Mobile telecommunication and broadcast technology converge. Western European markets for mobile handsets are saturated and mobile handsets are now commodity. Digital TV as well as is just about to become reality in many European countries. Both fields converge. Broadcast offerings will more and more reach out to mobile handsets and vice versa. In this paper we share our view on

D. Florescu; J.-M. Hasemann

2005-01-01

489

Communication.  

ERIC Educational Resources Information Center

|The following essays on communication are presented: communication as a condition of survival, communication for special purposes, the means of transmission of communication, communication within social and economic structures, the teaching of communication through the press, the teaching of modern languages, communication as a point of…

Strauss, Andre

490

A 24-pole high Tc superconducting filter for mobile communication applications  

NASA Astrophysics Data System (ADS)

This paper presents a highly selective 24-pole Chebyshev HTS bandpass filter. The filter was designed at 1748 MHz centre frequency with 75 MHz bandwidth, which was suitable for the GSM base station. The filter was fabricated using double-sided YBCO films on a 3 in diameter, 0.43 mm thick sapphire substrate. The simulation of the filter performance was carried out using Sonnet software. A novel resonator structure was proposed. The resonator exhibited a very high Q value of about 30 000 at 77 K. The filter showed an excellent selectivity. At the band edge of the filter, the slope was about 17 dB MHz-1. Out of the band, the rejection level is better than -90 dB.

Zhang, Xueqiang; Meng, Qingduan; Li, Fei; Li, Chunguang; Li, Shunzhou; He, Aisheng; Li, Hong; He, Yusheng

2006-05-01

491

Distributed Nonlinear Power Control in Cellular Mobile Networks With Each User Communicating With Several Base Stations  

Microsoft Academic Search

A simple distributed power control algorithm for communication networks with each user communicating with several base stations is proposed. We prove that the proposed algorithm is globally converging

Andrey V. Savkin

2007-01-01

492

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

PubMed

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

Reyhani, S M S; Ludwig, Simone A

2006-10-01

493

DSD (Double Soft Decision) concatenated FEC scheme on mobile satellite communication systems  

NASA Astrophysics Data System (ADS)

In order to realize a higher-code-gain forward error correction scheme in mobile satellite communication systems, a novel concatenated coding scheme employng soft decision decoding for not only inner codes but also outer codes (DSD (Double Soft Decision) concatenated forward error correction scheme) is proposed. Soft-decision outer decoding can improve the bit error probability of inner decoded data, which traditionally cannot be sufficiently corrected in fading channels. In this scheme, likelihood information from an inner Viterbi decoder is used in the decoding of outer codes. A technique using the path memory circuit status 1.0 ratio for likelihood information is newly proposed, and it is shown that this method is the most reliable even though it requires the simplest hardware among the alternative likelihood information extracting methods. A computer simulation clarifies that the proposed DSD scheme improves Pe performance to one-third that of the conventional hard-decision outer decoding. Moreover, to reduce the interleaving delay time in fading channel or inner decoded data of concatenated codes, a parallel forward error correction scheme is proposed.

Honda, Shunji; Kubota, Shuji; Kato, Shuzo

1992-10-01

494

Flexible coprocessor architectures for ambient intelligent applications in the mobile communication and automotive domain  

NASA Astrophysics Data System (ADS)

Ambient Intelligent is expected to become one of the driving key factors of the semiconductors industry in this decade. One of the most promising areas in this respect is the advent of embedded smart imaging applications in a variety of consumer applications, like mobile communication devices and the automotive domain. The efficient VLSI implementation of these applications requires architectural concepts that enable the extraction of objects and associated information out of video sequences in real-time. The main architectural challenge is to find an appropriate trade-off between architectural flexibility and scalability in order to cope with moderate variations of the applied smart imaging algorithms on one hand and cost efficiency of the implementation on the other hand. This paper describes the algorithmic and architectural requirements for the implementation of smart imaging applications in the mentioned fields. The target system, based on an embedded RISC processor, embedded memory, and cores for accelerating essential functions, like morphological operations, connected component labeling, motion extraction etc., is presented. The functional system partitioning applied is based on HW acceleration of core functions that enable the extraction of low-level information out of the images of a video sequence. This information is provided to the embedded RISC processor for further abstraction of the image content information and interpretation of the image content by SW means. One of the focal points of this paper is the derivation of efficient architectural concepts for smart imaging coprocessors, acting as a system toolbox for accelerating the required smart imaging core functions.

Gehrke, Winfried; Jachalsky, Joern; Wahle, Martin; Kruijtzer, Wido; Alba, Carlos; Sethuraman, Ramanathan

2003-04-01

495

Evaluation of root-normalised front-end (RN LFCC) for speech recognition in wireless GSM network environments  

Microsoft Academic Search

With the emergence of mobile telephony, the conditions of use of speech recognisers have been completely reconsidered. Speech can be input from a wide range of environments, having to face several degradation causes principally induced by noise and\\/or channel distortions. The root-normalised front-end is evaluated on several databases. Special attention is given to the GSM environment where noise, channel and

S. Dufour; C. Glorion; P. Lockwood

1996-01-01

496

Printed Monopole Slot Antenna for Internal Multiband Mobile Phone Antenna  

Microsoft Academic Search

A new internal multiband mobile phone antenna formed by two printed monopole slots of different lengths cut at the edge of the system ground plane of the mobile phone is presented. The antenna can generate two wide bands centered at about 900 and 2100 MHz to cover the GSM850\\/GSM900\\/DCS\\/PCS\\/UMTS bands and the 2.4-GHz WLAN band. Further, the antenna has a

Chun-I. Lin; Kin-Lu Wong

2007-01-01

497

An internal dual-band mobile phone antenna  

Microsoft Academic Search

An internal dual-band mobile phone antenna designed to operate at GSM900 and GSM1800 bands is presented. The antenna is derived from a quarter-wave planar inverted F-type antenna, which has at this state proved to be the most promising candidate for mobile applications due to its compact size and good performance. The FDTD method is used in the study and an

S. Tarvas; A. Isohatala

2000-01-01

498

Does technological standardization enhance or inhibit firm's capabilities? Research on dynamic capabilities in the mobile communication market  

Microsoft Academic Search

Mobile communication market presents drastically technology changes from the first generation (1G), second generation (2G), third generation (3G) and next fourth generation(4G) in progress. It's also apparently characterized with the industry standardization, which specifies compatibility and interoperability of the product, with the objective of increasing the efficiency of economic activity. Standardization will convey direct competitive advantage to the owner of

Hsiao-Chen Mei; Joseph L. Che; Shihmin Lo; Peter J. Sher

2010-01-01

499

Block Edge Mask Baseline Limits for Mobile Communication Network Base Stations in the 790-862 MHz Digital Dividend Spectrum  

Microsoft Academic Search

This paper reports on a study undertaken by the CEPT SE42 project team, with the objective of deriving regulatory radiation limits which mitigate the impact of adjacent-channel interference from fixed\\/mobile communication network base stations (BSs) in the 790-862 MHz Digital Dividend spectrum to digital terrestrial television (DTT) services below 790 MHz. A novel stochastic approach for the calculation of BS

H. R. Karimi; G. Warren; M. Fenton; G. Lapierre; T. O'Leary; W. Sami

2010-01-01

500

Least-Squares Channel Estimation for Mobile OFDM Communication on Time-Varying Frequency-Selective Fading Channels  

Microsoft Academic Search

A least-squares (LS) channel estimation (CE) technique for mobile orthogonal frequency-division multiplexing (OFDM) communications over a rapidly time-varying frequency-selective fading channel is investigated in this paper. The proposed technique keeping the comb-type pilot arrangement can achieve a low error probability by accurately estimating channel impulse response (CIR) and effectively tracking rapid CIR time variations. The LS CE technique proposed here

Jia-Chin Lin

2008-01-01