Sample records for mobile communications research

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

    E-print Network

    Abu-Rgheff, Mosa Ali

    University of Plymouth,University of Plymouth, SoCCESoCCE, Mobile Communications Research Group, Mobile Communications Research Group Dr Mosa Ali AbuDr Mosa Ali Abu--RgheffRgheff -- ENFERENFER JulienJulien INC2004INC2004 Seamless Communications for Mobile Emergency ServicesSeamless Communications for Mobile

  2. Radiowave propagation in mobile communications: an overview of European research

    Microsoft Academic Search

    B. H. Fleury; P. E. Leuthold

    1996-01-01

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

  3. Channel simulation to facilitate mobile-satellite communications research

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz

    1987-01-01

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

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

    E-print Network

    Gruenwald, Le

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

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

    ERIC Educational Resources Information Center

    Gary, Brett

    1996-01-01

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

  6. Channel Simulation to Facilitate Mobile-Satellite Communications Research

    Microsoft Academic Search

    Faramaz Davarian

    1987-01-01

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

  7. Mobile satellite communications

    Microsoft Academic Search

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

    1994-01-01

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

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

    Microsoft Academic Search

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

    2009-01-01

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

  9. Mobile Communications May 30, 2013

    E-print Network

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

  10. Reliable Communication for Highly Mobile Agents

    Microsoft Academic Search

    Amy L. Murphy; Gian Pietro Picco

    1999-01-01

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

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

    Microsoft Academic Search

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

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

  12. On fundamental concept of mobility for mobile communications

    Microsoft Academic Search

    Jun-Zhao Sun; Jaakko Sauvola

    2002-01-01

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

  13. Mobile Communication: The Misunderstood User

    Microsoft Academic Search

    Giuseppe Lugano; Anna Kämäräinen; Tero Heiskainen

    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

  14. Reliable Communication for Highly Mobile Agents Amy L. Murphy

    E-print Network

    Picco, Gian Pietro

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

  15. A study on the service quality of mobile communication industry

    Microsoft Academic Search

    Yongrui Duan; Liqin Sun

    2011-01-01

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

  16. Telemedicine by mobile communication

    Microsoft Academic Search

    Koichi Shimizu

    1999-01-01

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

  17. 1. Final Title SECURITY of MOBILE COMMUNICATIONS

    E-print Network

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

  18. Mobile Communication Via Satellite

    NASA Technical Reports Server (NTRS)

    Yan, Tsun-Yee; Naderi, Firouz M.

    1988-01-01

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

  19. Going Places: Exploring the Impact of Intra-Sectoral Mobility on Research Productivity and Communication Behaviors in Japanese Academia

    ERIC Educational Resources Information Center

    Horta, Hugo; Yonezawa, Akiyoshi

    2013-01-01

    This study analyzes the impact of intra-sectoral mobility of academics on research productivity and R&D information exchange dynamics in Japan. The analysis shows intra-sectoral mobility impacting positively both research productivity and information exchange dynamics, but that this effect--except for information exchange with peers based…

  20. Communication and Mobility Control in Boxed Ambients

    E-print Network

    Bugliesi, Michele

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

  1. Mobile Communication Device (MCD) Justification Form

    E-print Network

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

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

    E-print Network

    Dyer, Bill

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

  3. Trends in mobile satellite communication

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    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.

  4. Control Freaks How Online and Mobile Communication

    E-print Network

    Lansky, Joshua

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

  5. Les interfaces intelligentes et les communications mobiles

    E-print Network

    Paris-Sud XI, Université de

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

  6. Multidimensional Human Dynamics in Mobile Phone Communications

    PubMed Central

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

    2014-01-01

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

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

    Microsoft Academic Search

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

    2009-01-01

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

  8. Human-Centered Approach Evaluating Mobile Sign Language Video Communication

    E-print Network

    Wobbrock, Jacob O.

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

  9. Department of Mobile Communications 2229, route des Crtes

    E-print Network

    Gesbert, David

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

  10. Application of Mobile Router to Military Communications

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  11. Personal mobile communications in microwave band

    Microsoft Academic Search

    Yuji Kitahara

    1993-01-01

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

  12. Communication and Mobility Control in Boxed Ambients

    E-print Network

    Merro, Massimo

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

  13. Mobile Communications Device Allowances Frequently Asked Questions

    E-print Network

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

  14. Communications Systems for Mobile Robotics

    SciTech Connect

    Futterman, J A; Pao, H

    2003-12-08

    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).

  15. Antennas for mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Huang, John

    1991-01-01

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

  16. Communication Interference in Mobile Boxed Ambients

    E-print Network

    Bugliesi, Michele

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

  17. Experiment In Aeronautical-Mobile/Satellite Communication

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  18. Summer 2007 Mobile and Wireless Communications

    E-print Network

    Dyer, Bill

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

  19. MOBILE COMMUNICATIONS AND HOME COMPUTING POLICY Policy Statement

    E-print Network

    Shahriar, Selim

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

  20. Pseudodifferential operators and Banach algebras in mobile communications

    E-print Network

    Strohmer, Thomas

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

  1. Tracking mobile users in wireless communications networks

    Microsoft Academic Search

    Amotz Bar-Noy; Ilan Kessler

    1993-01-01

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

  2. Reinventing Mobile Community Computing and Communication

    E-print Network

    Paris-Sud XI, Université de

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

  3. Effective Protocols for Mobile Communications and Networking

    SciTech Connect

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

    1998-12-01

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

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

    E-print Network

    Ansari, Nirwan

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

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

    ERIC Educational Resources Information Center

    Evans, Susan T.

    2011-01-01

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

  6. Challenges for Nomadic Computing: Mobility Management and Wireless Communications

    E-print Network

    Yener, Aylin

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

  7. Design of Hybrid Mobile Communication Networks for Planetary Exploration

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  8. Space communications technology research in CRL

    NASA Astrophysics Data System (ADS)

    Iida, Takashi

    1993-03-01

    This report overviews the current research of space communications technology in Communications Research Laboratory (CRL), Ministry of Posts, and Telecommunications. The Engineering Test Satellite-5 (ETS-5) project has been conducted these five years for mobile communications development. The international cooperations using ETS-5 has been performed. It describes the project of Communications and Broadcasting Engineering Test Satellite (COMETS) to be launched in 1997 for experiments of advanced mobile satellite communication and advanced broadcasting. It also mentions the project of Engineering Test Satellite-6 (ETS-6), to be launched in 1994, in which the CRL's missions of ETS-6 are the inter-satellite communication of S-band, millimeter-wave, and optical. Finally, this report describes the technologies of large antenna assembly experiment, small satellite communications, and cluster satellite briefly.

  9. CDMA overlay situations for microcellular mobile communications

    Microsoft Academic Search

    Jiangzhou Wang; Laurence B. Milstein

    1995-01-01

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

  10. Repeated Transmissions In Mobile/Satellite Communications

    NASA Technical Reports Server (NTRS)

    Yan, Tsun-Yee; Clare, Loren P.

    1988-01-01

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

  11. USDA Forest Service mobile satellite communications applications

    NASA Technical Reports Server (NTRS)

    Warren, John R.

    1990-01-01

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

  12. Impacts of mobile agent technology on mobile communication system evolution

    Microsoft Academic Search

    LARS HAGEN; MARKUS BREUGST

    1998-01-01

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

  13. SECURE AUTHENTICATION FOR MOBILE COMMUNICATION OVER THE INTERNET1

    E-print Network

    von Bochmann, Gregor

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

  14. Research on Mobile GIS Based for Information Collection

    Microsoft Academic Search

    Chen Feixiang; Zhao Ming; Qi Jiandong; Jiang Xiaoru

    2009-01-01

    With the rapid development of GIS, embedded technology and wireless communication technology, mobile GIS becomes an active research area in the field of GIS. Mobile computing system based on personal digital assistant (PDA) products has been used widely, and information collection is one of the most promising application directions of mobile GIS. The purpose of the paper is to propose

  15. A Communication Architecture for an Advanced Extravehicular Mobile Unit

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  16. Mobile satellite communications in the Forest Service

    NASA Technical Reports Server (NTRS)

    Warren, John R.

    1988-01-01

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

  17. 78 FR 32689 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

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

  18. Enabling Disconnected Transitive Communication in Mobile Ad Hoc Networks

    Microsoft Academic Search

    Xiangchuan Chen; Amy L. Murphy

    2001-01-01

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

  19. The Role of Mobile Phones in Family Communication

    ERIC Educational Resources Information Center

    Devitt, Kerry; Roker, Debi

    2009-01-01

    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…

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

    E-print Network

    Lee, Tae-Jin

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

  1. Modeling and Analysis of Mobility Management in Mobile Communication Networks

    PubMed Central

    Yoon, Ji Hyun; Kim, Chesoong

    2014-01-01

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

  2. Modeling and analysis of mobility management in mobile communication networks.

    PubMed

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

    2014-01-01

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

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

    E-print Network

    Shieh, Shiuhpyng Winston

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

  4. Mobile satellite communications for consumers

    NASA Astrophysics Data System (ADS)

    Noreen, Gary K.

    1991-11-01

    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.

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

    Microsoft Academic Search

    Mikko V. J. Heikkinen; Sakari Luukkainen

    2010-01-01

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

  6. Microstrip monopulse antenna for land mobile communications

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

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

    E-print Network

    Paris-Sud XI, Université de

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

  8. Communicating University Research.

    ERIC Educational Resources Information Center

    Alberger, Patricia L., Ed.; Carter, Virginia L., Ed.

    Techniques for science writers are outlined in a handbook designed to help research communicators define their field and to understand better the world of the researcher. It is argued that the public appetite for news about science is considerable and that the public's understanding of science would be fostered through collaboration among…

  9. Providing Seamless Communication in Mobile Wireless Networks

    E-print Network

    Vaidya, Nitin

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

  10. Frontiers of Wireless and Mobile Communications

    E-print Network

    Mandayam, Narayan

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

  11. GSM: Global System for Mobile communications

    E-print Network

    Abrardo, Andrea

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

  12. Communicating and Mobile Systems: The ?-calculus

    Microsoft Academic Search

    Robin Milner

    1999-01-01

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

  13. Mobile target tracking with communication delays

    Microsoft Academic Search

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

    2004-01-01

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

  14. Laser Communication Between Mobile Platforms

    Microsoft Academic Search

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

    2009-01-01

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

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

    E-print Network

    Bencsáth, Boldizsár

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

  16. Lecture Series in Mobile Telecommunications and Networks Wireless Communications

    E-print Network

    Toh, C-K.

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

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

    E-print Network

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

  18. DCM 2005 Preliminary Version Splitting Mobility and Communication in

    E-print Network

    Compagnoni, Adriana

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

  19. Autonomous mobile mailbox model for communication cost reduction

    Microsoft Academic Search

    I. Cavrak; A. Stranjak; M. Zagar

    2004-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  1. Antenna technology for advanced mobile communication systems

    NASA Technical Reports Server (NTRS)

    Rammos, Emmanuel; Roederer, Antoine; Rogard, Roger

    1988-01-01

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

  2. Mobile Advertising in Business-to-Business Communications

    Microsoft Academic Search

    Tiina Takkula; Jaana Tähtinen

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

  3. Mobile data communications in Germany-a survey

    Microsoft Academic Search

    Bernhard H. Walke

    1994-01-01

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

  4. Reliable Communication for Highly Mobile Agents Amy L. Murphy

    E-print Network

    Picco, Gian Pietro

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

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

    E-print Network

    Gesbert, David

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

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

    E-print Network

    Monteiro, Edmundo

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

  7. Hybrid Mobile Communication Networks for Planetary Exploration

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

  8. Multi-agent system security for mobile communication

    E-print Network

    Dent, Alexander W.

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

  9. Communication base contenus dans les rseaux mobiles ad hoc discontinus

    E-print Network

    Paris-Sud XI, Université de

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

  10. Mobile user experience research: challenges, methods & tools

    Microsoft Academic Search

    Yelena Nakhimovsky; Dean Eckles; Jens Riegelsberger

    2009-01-01

    We are currently witnessing rapid innovation in mobile user experience (UX) research. The HCI community is creating and adapting research methods, tools, and infrastructure for mobile-specific challenges and opportunities. This workshop brings together researchers from industry and academia, designers, and creators of research tools, who faced the challenges of mobile UX research and responded with innovative approaches. We will examine

  11. Frequency addressable beams for land mobile communications

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  12. Aeronautical Mobile Airport Communications System (AeroMACS)

    NASA Technical Reports Server (NTRS)

    Budinger, James M.; Hall, Edward

    2011-01-01

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

  13. Structure and tie strengths in mobile communication networks

    Microsoft Academic Search

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

    2007-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Gao, Gan

    2014-12-01

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

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

    NASA Astrophysics Data System (ADS)

    Noreen, Gary K.

    1990-12-01

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

  16. Consensus in networks of mobile communicating agents

    NASA Astrophysics Data System (ADS)

    Baronchelli, Andrea; Díaz-Guilera, Albert

    2012-01-01

    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.

  17. Biometric Communication Research for Television.

    ERIC Educational Resources Information Center

    Malik, M. F.

    Biometric communication research is defined as research dealing with the information impact of a film or television show, photographic picture, painting, exhibition, display, or any literary or functional texts or verbal stimuli on human beings, both as individuals and in groups (mass audiences). Biometric communication research consists of a…

  18. Direction in AV communication research

    Microsoft Academic Search

    James D. Finn

    1954-01-01

    Summary  To summarize, it has been the thesis of this paper that research in AV communication embraces research in all areas of the\\u000a social sciences. Possibilities for future research were analyzed under four headings: (a) empirical investigation into classicial-type\\u000a effects problems, the mass media of communication, areas such as learning which are basic to communication study, and projective\\u000a and AV testing;

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

    ERIC Educational Resources Information Center

    Simonic, Tomaz; Mlinar, Tomi

    2000-01-01

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

  20. The Research on Ad Hoc Network-Based Mobile Service of Geospatial Information Towards 4G

    Microsoft Academic Search

    Yun Zhang; Fuling Bian

    2011-01-01

    The mobile geographic information service involves the domain of mobile communication, mobile computing, geographic information service and other techniques. Ad Hoc networks are infrastructureless networks formed by neighboring equipments with limited life, and are now envisioned as cornerstones of future generation networking technologies (B3G and 4G). This paper researches on the integration of above technologies and proposes architecture of mobile

  1. The mobile radio extension of the SOTRIN Area Communication System

    Microsoft Academic Search

    Angelo BRIGANTE; Giovanni GUIDOTTI

    1992-01-01

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

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

    E-print Network

    Wong, Vincent

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

  3. 76 FR 63657 - Certain Devices for Mobile Data Communication; Notice of Institution of Investigation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

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

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

    E-print Network

    Gesbert, David

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

  5. 75 FR 3914 - Recordation of Trade Name “Sony Ericsson Mobile Communications AB”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

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

  6. 78 FR 38361 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-26

    ...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...

  7. Interference Analysis for an Aeronautical Mobile Airport Communications System

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Kercewski, Robert J.

    2010-01-01

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

  8. Interference Analysis for an Aeronautical Mobile Airport Communications System

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Kerczewski, Robert J.

    2011-01-01

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

  9. Mobile health for non-communicable diseases in Sub-Saharan Africa: a systematic review of the literature and strategic framework for research

    PubMed Central

    2014-01-01

    Background Mobile health (mHealth) approaches for non-communicable disease (NCD) care seem particularly applicable to sub-Saharan Africa given the penetration of mobile phones in the region. The evidence to support its implementation has not been critically reviewed. Methods We systematically searched PubMed, Embase, Web of Science, Cochrane Central Register of Clinical Trials, a number of other databases, and grey literature for studies reported between 1992 and 2012 published in English or with an English abstract available. We extracted data using a standard form in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results Our search yielded 475 citations of which eleven were reviewed in full after applying exclusion criteria. Five of those studies met the inclusion criteria of using a mobile phone for non-communicable disease care in sub-Saharan Africa. Most studies lacked comparator arms, clinical endpoints, or were of short duration. mHealth for NCDs in sub-Saharan Africa appears feasible for follow-up and retention of patients, can support peer support networks, and uses a variety of mHealth modalities. Whether mHealth is associated with any adverse effect has not been systematically studied. Only a small number of mHealth strategies for NCDs have been studied in sub-Saharan Africa. Conclusions There is insufficient evidence to support the effectiveness of mHealth for NCD care in sub-Saharan Africa. We present a framework for cataloging evidence on mHealth strategies that incorporates health system challenges and stages of NCD care. This framework can guide approaches to fill evidence gaps in this area. Systematic review registration: PROSPERO CRD42014007527. PMID:24927745

  10. A Review of Mobile HCI Research Methods

    Microsoft Academic Search

    Jesper Kjeldskov; Connor Graham

    2003-01-01

    This paper examines and reviews research methods applied within the field of mobile human-computer interaction. The purpose is to provide a snapshot of current practice for studying mobile HCI to identify shortcomings in the way research is conducted and to propose opportunities for future ap- proaches. 102 publications on mobile human-computer interaction research were categorized in a matrix relating their

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

    NASA Technical Reports Server (NTRS)

    Shamma, Mohammed A.

    2004-01-01

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

  12. Key Establishment Protocols for Secure Mobile Communications: A Selective Survey

    Microsoft Academic Search

    Colin Boyd; Anish Mathuria

    1998-01-01

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

  13. Applying mobile IP over wireless ATM communication networks

    Microsoft Academic Search

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

    2001-01-01

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

  14. RadioActive: Enabling Persistent Mobile Communications for Groups

    E-print Network

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

  15. History of Antenna Technology for Mobile Communications in Korea

    NASA Astrophysics Data System (ADS)

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

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

  16. SAW based systems for mobile communications satellites

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  17. 78 FR 34132 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

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

  18. An Adaptive Communication Protocol for Cooperating Mobile Robots

    Microsoft Academic Search

    Holly Yanco; Lynn Andrea Stein

    1993-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Ichiyoshi, Osamu

    1990-01-01

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

  20. Towards a Mobile Workbench for Researchers

    Microsoft Academic Search

    Andreas Hense; Florian Quadt; Matthias Römer

    2009-01-01

    Mobile devices as the {iPhone} and Android-based smartphones can be turned into useful tools for researchers in the field. The concept of a scholarly or scientific workbench can be extended by a mobile usage scenario, where the researcher takes photographs, records sounds, and performs basic metadata editing. We present the prototype and the architecture of a mobile workbench that uploads

  1. FD/DAMA Scheme For Mobile/Satellite Communications

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  2. Mobile research strategies for a global market

    Microsoft Academic Search

    Colleen Page

    2005-01-01

    The user-centered design focus at Microsoft has evolved in parallel with emerging mobile technologies. We started with a Contextual Inquiry (CI) initiative in 1997 to gather mobile communication and information requirements in the Northwest U.S. Later, as users adopted wireless data services---Short Message Service (SMS), Wireless Application Protocol (WAP), mobile instant messenger, and email clients---the focus turned to more specific

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

    Microsoft Academic Search

    Stefan Marti

    2002-01-01

    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

  4. Mobile communications via satellite in the 1990s

    NASA Astrophysics Data System (ADS)

    Lundberg, O.

    1984-07-01

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

  5. Communication Concepts for Mobile Agent Systems

    Microsoft Academic Search

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

    1997-01-01

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

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

    E-print Network

    Shen, Xuemin "Sherman"

    2012-01-01

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

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

    E-print Network

    Wheeler, Patrick Sean

    2010-01-01

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

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

    Microsoft Academic Search

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

    1997-01-01

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

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

    Microsoft Academic Search

    Tetsuro Kobayashi; Jeffrey Boase

    2012-01-01

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

  10. Inferring human mobility using communication patterns

    E-print Network

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

    2014-01-01

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

  11. Mobile ad hoc networks for oceanic aircraft communications

    E-print Network

    Kingsbury, Ryan W

    2009-01-01

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

  12. A survey of various propagation models for mobile communication

    Microsoft Academic Search

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

    2003-01-01

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

  13. Performance of CDMA mobile communication systems using antenna arrays

    Microsoft Academic Search

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

    1993-01-01

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

  14. Effect of MobileASL on Communication Among Deaf Users

    E-print Network

    Wobbrock, Jacob O.

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

  15. GSM-PKI solution enabling secure mobile communications.

    PubMed

    Jelekäinen, Pekka

    2004-03-31

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

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

    E-print Network

    Kansas, University of

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

  17. Application-driven power management for mobile communication

    Microsoft Academic Search

    Robin Kravets; P. Krishnan

    2000-01-01

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

  18. Current Approaches to Authentication in Wireless and Mobile Communications Networks

    Microsoft Academic Search

    G. Schäfer; A. Festag; H. Karl

    2001-01-01

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

  19. Optimization of Wireless Resources for Personal Communications Mobility Tracking

    Microsoft Academic Search

    Upamanyu Madhow; Michael L. Honig; Kenneth Steiglitz

    1994-01-01

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

  20. A scalable group communication mechanism for mobile agents

    Microsoft Academic Search

    Hojjat Jafarpour; Nasser Yazdani; Navid Bazzaz-zadeh

    2007-01-01

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

  1. Research design for technical communications

    Microsoft Academic Search

    L. K. Grove; P. R. Seesing

    1991-01-01

    The authors consider how one can design research studies so that they meet the needs of the technical communications community and serve as the basis of a unified theory. This research design involves the following steps: establish hypotheses to clearly identify what it is that you are trying to find out; determine how you can test those hypotheses and only

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

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  3. Signalling characteristics in satellite-aided land mobile communications

    NASA Technical Reports Server (NTRS)

    Anderson, R. E.

    1982-01-01

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

  4. Wireless Communication Enhancement Methods for Mobile Robots in Radiation Environments

    E-print Network

    Nattanmai Parasuraman, Ramviyas; Ferre, Manuel

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

  5. Cockpit weather graphics using mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Seth, Shashi

    1993-01-01

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

  6. Tracking Mobile Users in Wireless Communication Networks

    Microsoft Academic Search

    Amotz Bar-noy; Ilan Kessler

    1993-01-01

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

  7. Intelligent network concepts in mobile communications

    Microsoft Academic Search

    Bijan Jabbari

    1992-01-01

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

  8. Inferring human mobility using communication patterns

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  9. Inferring human mobility using communication patterns.

    PubMed

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

    2014-01-01

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

  10. Inferring human mobility using communication patterns

    PubMed Central

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

    2014-01-01

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

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

    Microsoft Academic Search

    ABDULKADER S. AKKI; F. Haber

    1986-01-01

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

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

    E-print Network

    Anderson, Richard

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

  13. Mobile satellite communications systems: Toward global personal communications

    Microsoft Academic Search

    John H. Lodge

    1991-01-01

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

  14. Development of a mobile satellite communication unit

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

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

    E-print Network

    Wolff, Richard

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

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

    E-print Network

    Carlini, David

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

  17. Physiological Measurement in Communication Research.

    ERIC Educational Resources Information Center

    Behnke, Ralph R.

    1970-01-01

    The importance of effective communication compels investigators to seek new ways of measuring physiological responses and to practice the science of psychophysiology. The main objective of psychophysiological research is to describe the systems in organisms which transfer information between the subsystems of soma and psyche. Results should lead…

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

    NASA Astrophysics Data System (ADS)

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

    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.

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

    NASA Astrophysics Data System (ADS)

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

    1993-10-01

    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.

  20. A group communication approach for mobile computing

    Microsoft Academic Search

    K. Cho; K. P. Birmans

    1994-01-01

    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

  1. Linear amplification technique for digital mobile communications

    Microsoft Academic Search

    Yoshinori Nagata

    1989-01-01

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

  2. Biological aspects of mobile communication fields

    Microsoft Academic Search

    James C. Lin

    1997-01-01

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

  3. Potential markets for a satellite-based mobile communications system

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

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

    Microsoft Academic Search

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

    1995-01-01

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

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

    Microsoft Academic Search

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

    2004-01-01

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

  6. [Communicating research with social media].

    PubMed

    Bennato, Davide

    2014-09-01

    Participation is the new keyword of communication. In the scientific field, communication is a very complex task that can't ignore the careful consideration of the target audience. To minimize the difficulties, it is useful to rely on storytelling: it can greatly benefit from the space offered by social media that can be used to raise awareness and to engage through the sharing of experiences. The marriage between scientific research and social media can take place, as long as you carefully reflect on the roles, strategies and appropriate tools. PMID:25229757

  7. Mobile Robotics: Research, Applications and Challenges

    E-print Network

    Nehmzow, Ulrich

    with enormous potential is that of mobile entertainment robots. It is obvious that a range of fundamentalMobile Robotics: Research, Applications and Challenges Ulrich Nehmzow Department of Computer Science The University of Manchester Manchester M13 9PL United Kingdom http://www.cs.man.ac.uk/robotics

  8. Mobility Research and Production Sciences

    E-print Network

    . Robert Fischer, Vice President Engineering and Technology, Powertrain Engineering AVL Matthias H. Koch. Koch, Siemens Mobility Graz 17.40 uhr Impulsreferat ,,die rolle des Verbrennungsmotors für die

  9. Department of Mobile Communications Campus Sophia Tech

    E-print Network

    Gesbert, David

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

  10. Mobile satellite service communications tests using a NASA satellite

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  11. Optimization of wireless resources for personal communications mobility tracking

    Microsoft Academic Search

    Upamanyu Madhow; Michael L. Honig; Kenneth Steiglitz

    1995-01-01

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

  12. Mobile satellite communications - Applications for developing countries

    NASA Astrophysics Data System (ADS)

    von Noorden, Wolf D.

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

  13. Mobile robotics research at Sandia National Laboratories

    SciTech Connect

    Morse, W.D.

    1998-09-01

    Sandia is a National Security Laboratory providing scientific and engineering solutions to meet national needs for both government and industry. As part of this mission, the Intelligent Systems and Robotics Center conducts research and development in robotics and intelligent machine technologies. An overview of Sandia`s mobile robotics research is provided. Recent achievements and future directions in the areas of coordinated mobile manipulation, small smart machines, world modeling, and special application robots are presented.

  14. 76 FR 80402 - Certain Personal Data and Mobile Communications Devices and Related Software; Final Determination...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-23

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

  15. 77 FR 40083 - Certain Personal Data and Mobile Communications Devices and Related Software; Institution of a...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-06

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

  16. 77 FR 60721 - Certain Devices for Mobile Data Communication; Notice of Commission Determination Not To Review...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-04

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

  17. 77 FR 69501 - Certain Devices for Mobile Data Communication; Determination Not To Review an Initial...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-19

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

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

    E-print Network

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

  19. Land-mobile satellite communication system

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  20. Satellite-aided mobile communications, experiments, applications and prospects

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Bartholome, P.; Rogard, R.

    1988-01-01

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

  2. Mobile Visual Communication Photo Messages and Camera Phone Photography

    Microsoft Academic Search

    MIKKO VILLI

    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

  3. A study of adaptive arrays for mobile communication systems

    Microsoft Academic Search

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

    1991-01-01

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

  4. Performance of an OFDM-TDMA mobile communication system

    Microsoft Academic Search

    H. Rohling; R. Griinheid

    1996-01-01

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

  5. A Model and Measure of Mobile Communication Competence

    ERIC Educational Resources Information Center

    Bakke, Emil

    2010-01-01

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

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

    Microsoft Academic Search

    J. Bach Andersen

    2000-01-01

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

  7. Performance of CDMA\\/OFDM for mobile communication system

    Microsoft Academic Search

    K. Fazel

    1993-01-01

    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

  8. A Facial Sketch Animation Generator for Mobile Communication

    Microsoft Academic Search

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

    2007-01-01

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

  9. Channel-Individual Adaptive Beamforming for Mobile Satellite Communications

    Microsoft Academic Search

    Thomas Gebauer; Heinz G. Göckler

    1995-01-01

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

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

    E-print Network

    Leung, Kin K.

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

  11. An Architecture for Security and Privacy in Mobile Communications

    Microsoft Academic Search

    G. Winfield Treese; Lawrence C. Stewart

    2001-01-01

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

  12. Safety Monitoring System by Autonomous Mobile Sensors Utilizing Pheromone Communication

    Microsoft Academic Search

    Kenji Tanaka; Yo Ishigaki; Hiroyulu Inoue; Makoto Itoh

    2005-01-01

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

  13. Daily rhythms in mobile telephone communication

    E-print Network

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

    2015-01-01

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

  14. Spread spectrum mobile communication experiment using ETS-V satellite

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Davarian, F.; Sumida, J.

    1986-01-01

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

  16. Mobility of a Disaster Recover Communication System

    Microsoft Academic Search

    Edward Sobanski; Barbara Nicolai

    2011-01-01

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

  17. Sharing Resources In Mobile/Satellite Communications

    NASA Technical Reports Server (NTRS)

    Yan, Tsun-Yee; Sue, Miles K.

    1992-01-01

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

  18. George Spanogiannopoulos CSE 5431 Mobile Communications

    E-print Network

    Vlajic, Natalija

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

  19. The application of mobile satellite services to emergency response communications

    NASA Technical Reports Server (NTRS)

    Freibaum, J.

    1980-01-01

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

  20. A communication infrastructure to ease the development of mobile collaborative applications

    Microsoft Academic Search

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

    2010-01-01

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

  1. A communication infrastructure to ease the development of mobile collaborative applications

    Microsoft Academic Search

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

    2011-01-01

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

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

    E-print Network

    Egerstedt, Magnus

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

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

    E-print Network

    Minnesota, University of

    as mobile hubs to provide communication services on-demand. This capability is especially valuable in disaster response scenarios where there is no communication infrastructure. In such scenarios, mobile hubs study the efficient use of mobile robots to create a communication bridge between a source

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

    E-print Network

    Zhong, Lin

    1 BeamSwitch: System Solution for Energy-Efficient Directional Communication on Mobile Devices present a system solution, BeamSwitch, for directional communication on mobile de- vices. Beam been devoted to directional communication, few have studied it for mobile devices, which can not only

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

    E-print Network

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

  6. Frequency diversity for OFDM mobile communication via underwater acoustic channels

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

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

  7. Circadian pattern and burstiness in mobile phone communication

    NASA Astrophysics Data System (ADS)

    Jo, Hang-Hyun; Karsai, Márton; Kertész, János; Kaski, Kimmo

    2012-01-01

    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.

  8. Distributed Communication for Highly Mobile Agents Mohammad Samarah and Philip Chan

    E-print Network

    Chan, Philip K.

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

  9. Research on Mobile GIS: Characteristics, Frame and Key Technologies

    Microsoft Academic Search

    Chen Guoliang; Wang Yunjia; Wang Jian

    2010-01-01

    With the rapid development of internet and communication technologies, mobile computing has become a main computational method nowadays, and geographic information system based on mobile computing is the extension of mobile computing in the spatial information field. It can be forecasted that Mobile GIS will become the next luminescent point of GIS industry. This paper set forth the concept of

  10. Mobile Raman spectroscopy in astrobiology research.

    PubMed

    Vandenabeele, Peter; Jehli?ka, Jan

    2014-12-13

    Raman spectroscopy has proved to be a very useful technique in astrobiology research. Especially, working with mobile instrumentation during fieldwork can provide useful experiences in this field. In this work, we provide an overview of some important aspects of this research and, apart from defining different types of mobile Raman spectrometers, we highlight different reasons for this research. These include gathering experience and testing of mobile instruments, the selection of target molecules and to develop optimal data processing techniques for the identification of the spectra. We also identify the analytical techniques that it would be most appropriate to combine with Raman spectroscopy to maximize the obtained information and the synergy that exists with Raman spectroscopy research in other research areas, such as archaeometry and forensics. PMID:25368355

  11. Emerging mobile and personal communication systems

    Microsoft Academic Search

    Raj Pandya

    1995-01-01

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

  12. Payload system tradeoffs for mobile communications satellites

    NASA Technical Reports Server (NTRS)

    Moody, H. J.

    1990-01-01

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

  13. MSAT aeronautical mobile satellite communications terminal development

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  14. The Globalstar mobile satellite system for worldwide personal communications

    NASA Astrophysics Data System (ADS)

    Wiedeman, Robert A.; Viterbi, Andrew J.

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

  15. The Globalstar mobile satellite system for worldwide personal communications

    NASA Technical Reports Server (NTRS)

    Wiedeman, Robert A.; Viterbi, Andrew J.

    1993-01-01

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

  16. Communicating Research to Small Drinking Water Systems: Dissemination by Researchers

    EPA Science Inventory

    This talk discusses the challenges of disseminating research relevant to small systems. The presentation discusses efforts by the U.S. EPA’s Office of Research and Development to effectively communicating drinking water information. In particular, communication approaches ...

  17. [Thematic Issue: Communication Theory and Research].

    ERIC Educational Resources Information Center

    Gouran, Dennis, Ed.

    1979-01-01

    The focus of the contributions to this journal issue is communication theory and research. Following an introductory article that deals with the need for quality control in the criticism of communication research, eight articles offer discussions of the following topics: the nature of criticism in rhetorical and communicative studies, some issues…

  18. Monitoring Heart Disease and Diabetes with Mobile Internet Communications

    PubMed Central

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

    2012-01-01

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

  19. Why is CDMA the solution for mobile satellite communication

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

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

  20. Study of terrestrial mobile systems for personal communications

    NASA Astrophysics Data System (ADS)

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

    1984-11-01

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

  1. Close relationships: A study of mobile communication records

    E-print Network

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

    2012-01-01

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

  2. Structure and tie strengths in mobile communication networks

    PubMed Central

    Onnela, J.-P.; Saramäki, J.; Hyvönen, J.; Szabó, G.; Lazer, D.; Kaski, K.; Kertész, J.; Barabási, A.-L.

    2007-01-01

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

  3. Close Relationships: A Study of Mobile Communication Records

    NASA Astrophysics Data System (ADS)

    Palchykov, Vasyl; Kertész, János; Dunbar, Robin; Kaski, Kimmo

    2013-05-01

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

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

    PubMed Central

    2014-01-01

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

  5. Research Priorities in Mobile Learning: An International Delphi Study

    ERIC Educational Resources Information Center

    Hsu, Yu-Chang; Ching, Yu-Hui; Snelson, Chareen

    2014-01-01

    Along with advancing mobile technologies and proliferating mobile devices and applications, mobile learning research has gained great momentum in recent years. While there have been review articles summarizing past research, studies identifying mobile learning research priorities based on experts' latest insights have been lacking. This study…

  6. Fixed and mobile multi-beam communications experiment payload

    NASA Astrophysics Data System (ADS)

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

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

  7. Fixed and mobile satellite communication systems for ETS-VI

    NASA Astrophysics Data System (ADS)

    Nakagawa, Kazuo; Kawai, Makoto; Tanaka, Masayoshi

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

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

  9. FEC decoder design optimization for mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Roy, Ashim; Lewi, Leng

    1990-01-01

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

  10. Sama: A Scalable Group Communication Mechanism for Mobile Agents

    E-print Network

    Hojjat Jafarpour; Nasser Yazdani; North Kargar St

    2003-01-01

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

  11. Research on Mobile SVG Map Service Based on Java Mobile Phone

    Microsoft Academic Search

    Dong Li; Yongxiong Zhang; Bingjun Yu; Ning Gu; Yuhui Peng

    2007-01-01

    One of the key issues to realizing map services in the GIS mobile system is to overcome the physical limitation of the mobile computing device, such as storage, CPU etc. This paper first proposed the resolution for mobile SVG map service on mobile phone, and then focused on the research of loading and displaying of mobile SVG map. The experiment

  12. Trellis-coded CPM for satellite-based mobile communications

    NASA Technical Reports Server (NTRS)

    Abrishamkar, Farrokh; Biglieri, Ezio

    1988-01-01

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

  13. Paths to consensus in networks of mobile communicating agents

    E-print Network

    Baronchelli, Andrea

    2011-01-01

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

  14. First satellite mobile communication trials using BLQS-CDMA

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  15. Prioritised dynamic communicating and mobile processes

    E-print Network

    Kent, University of

    programming language, based on the CSP process algebra [2­4]. It was originally designed for programming for the continued interest and devel- opment in the occam language, since the transputer production line stopped: Continuing research on language design, compilation and kernel support for highly dynamic concurrent reactive

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

    Microsoft Academic Search

    Zhang Shaojie; Wangxin; Wang Wenfeng

    2009-01-01

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

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

    E-print Network

    Finin, Tim

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

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

    E-print Network

    Vlad, Gregorio

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

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

    E-print Network

    Peng, Yun

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

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

    E-print Network

    Kolberg, Mario

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

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

    E-print Network

    Boyer, Edmond

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

  2. Research on UV scattering communication

    NASA Astrophysics Data System (ADS)

    Dong, Ke-yan; Lou, Yan; Ding, Ying; Wang, Shuo; Wang, Hongliang; Jiang, Hui-lin

    2013-08-01

    Ultraviolet (UV) scattering communication is a broadcast communication mode of information transmission by particles in the atmosphere scattering effect on the blind band ultraviolet light, there are many advantages such as unaffected by electromagnetic radiation, good confidentiality, non-line-of sight communication. This type communication mainly used in a short distance, secure communication, which was superior to no line communication in aspect of anti-jamming and secrecy. Firstly the military requirement of UV scattering communication is analyzed in this paper, The development trend is introduced, then the composition and working principle of ultraviolet scattering communication system are also discussed, The key influential factors of UV communication system path transmission loss effects on parameters such as receiver, transmitter and received beam divergence angle, pitch angle and the communication distance were analyzed. Attenuation was quantitatively simulated under different atmospheres, communication patterns and structure parameters. The results show that: transmission distance increases with increasing beam divergence angle and decreasing field angle. And the received view angle of influence on the communication distance is far greater than the emission beam divergence angle; transmission distance increases with increasing beam divergence angle and decreasing field and field angle effects on communication distance is greater than beam divergence angle.

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

    E-print Network

    Paris-Sud XI, Université de

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

  4. Mobile Interface for the Communication and Reference of DynamicTactical Information

    E-print Network

    Wurtele, Eve Syrkin

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

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

    E-print Network

    Kansas, University of

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

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

    Microsoft Academic Search

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

    2008-01-01

    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

  7. Driving forces of researchers mobility

    PubMed Central

    Gargiulo, Floriana; Carletti, Timoteo

    2014-01-01

    Starting from the dataset of the publication corpus of the APS during the period 1955–2009, we reconstruct the individual researchers trajectories, namely the list of the consecutive affiliations for each scholar. Crossing this information with different geographic datasets we embed these trajectories in a spatial framework. Using methods from network theory and complex systems analysis we characterise these patterns in terms of topological network properties and we analyse the dependence of an academic path across different dimensions: the distance between two subsequent positions, the relative importance of the institutions (in terms of number of publications) and some socio–cultural traits. We show that distance is not always a good predictor for the next affiliation while other factors like “the previous steps” of the career of the researchers (in particular the first position) or the linguistic and historical similarity between two countries can have an important impact. Finally we show that the dataset exhibit a memory effect, hence the fate of a career strongly depends from the first two affiliations. PMID:24810800

  8. Driving forces of researchers mobility

    NASA Astrophysics Data System (ADS)

    Gargiulo, Floriana; Carletti, Timoteo

    2014-05-01

    Starting from the dataset of the publication corpus of the APS during the period 1955-2009, we reconstruct the individual researchers trajectories, namely the list of the consecutive affiliations for each scholar. Crossing this information with different geographic datasets we embed these trajectories in a spatial framework. Using methods from network theory and complex systems analysis we characterise these patterns in terms of topological network properties and we analyse the dependence of an academic path across different dimensions: the distance between two subsequent positions, the relative importance of the institutions (in terms of number of publications) and some socio-cultural traits. We show that distance is not always a good predictor for the next affiliation while other factors like ``the previous steps'' of the career of the researchers (in particular the first position) or the linguistic and historical similarity between two countries can have an important impact. Finally we show that the dataset exhibit a memory effect, hence the fate of a career strongly depends from the first two affiliations.

  9. VLBI of the Communications Research Laboratory

    NASA Astrophysics Data System (ADS)

    Takaba, Hiroshi

    1991-11-01

    The Communications Research Laboratory has four antennas dedicated to VLBI observations, the diameters are 3 m, 10 m, 26 m, and 34 m. The two largest antennas, 26 m and 34 m, are used mainly for international VLBI experiments: geodesy, earth rotation study, and radio astronomy. The 3-m antenna and the 10-m antenna are used for domestic geodesy VLBI experiments. The 26-m antenna of the Kashima Space Research Center has S/X band receivers and has been used for international VLBI experiments since 1984. The 3-m antenna, which is the world smallest VLBI station, was developed for mobile experiments. The 10-m antenna at Marcus Island and the 34-m antenna at Kashima were completed in 1988. They are key stations in the Western Pacific VLBI network for monitoring tectonic plate motion around Japan. The surface accuracy of the 34-m antenna is 0.17 mm (rms). This enables it to be used at millimeter wavelengths. Ten low-noise radio astronomy frequency-band receivers from 300 MHz to 43 GHz are installed on the antenna. This paper describes the performance of CRL's VLBI antennas and gives details of the new 34-m antenna system including a new antenna pointing calibration method for medium-sized antennas.

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

    ERIC Educational Resources Information Center

    Ogara, Solomon Omondi

    2011-01-01

    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…

  11. Towards efficient mobile M2M communications: survey and open challenges.

    PubMed

    Pereira, Carlos; Aguiar, Ana

    2014-01-01

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

  12. Towards Efficient Mobile M2M Communications: Survey and Open Challenges

    PubMed Central

    Pereira, Carlos; Aguiar, Ana

    2014-01-01

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

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

    E-print Network

    Tang, Jia

    2009-05-15

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

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

    E-print Network

    Sanudin, Rahmat

    2014-06-30

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

  15. Overview of NASA Glenn Aero/Mobile Communications Demonstrations

    NASA Technical Reports Server (NTRS)

    Brooks, David; Hoder, Doug; Wilkins, Ryan

    2004-01-01

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

  16. Overview of NASA Glenn Aero/Mobile Communication Demonstrations

    NASA Technical Reports Server (NTRS)

    Brooks, David; Hoder, Doug; Wilkins, Ryan

    2004-01-01

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

  17. Communication Networks Research Laxmi Subedi, Mohamadreza Najiminaini, and Ljiljana Trajkovi, {lsa38, mna28, ljilja}@cs.sfu.ca

    E-print Network

    Trajkovic, Ljiljana

    networks," Proc. IEEE Int. Conf. on Wireless and Mobile Computing, Networking and Communications (Wi of public safety traffic on trunked land mobile radio systems," IEEE J. Select. Areas Commun., vol. 22, noCommunication Networks Research Laxmi Subedi, Mohamadreza Najiminaini, and Ljiljana Trajkovi, {lsa

  18. Cancer communication and informatics research across the cancer continuum.

    PubMed

    Hesse, Bradford W; Beckjord, Ellen; Rutten, Lila J Finney; Fagerlin, Angela; Cameron, Linda D

    2015-01-01

    Over the past decade, dramatic changes brought about by a rapid diffusion of Internet technologies, cellular telephones, mobile devices, personal digital assistants, electronic health records, and data visualization have helped to create a revolution in health communication. To understand the implications of this communication revolution for cancer care, the National Cancer Institute launched an ambitious set of research priorities under its "extraordinary opportunities" program. We present an overview of some of the relevant behavioral research being conducted within the perspective of this extraordinary opportunity in cancer communication research. We begin by tracing the implications of this research for behavioral scientists across the continuum of cancer care from primary prevention (e.g., tobacco control, diet, exercise, sun protection, and immunization against human papilloma virus), to secondary prevention (e.g., screening for polyps, lesions, and early stage neoplasms), to diagnosis and treatment, posttreatment survivorship, and end of life. Along each point of the continuum, we describe a natural evolution of knowledge from studies on the traditional role of media to research on the changing role of new media and informatics, and we carefully highlight the role that psychological research has played in improving communication- and health-related outcomes along the way. We conclude with an appeal to psychologists of many different backgrounds to join with biomedical researchers, engineers, clinical practitioners, and others to accelerate progress against cancer. (PsycINFO Database Record (c) 2015 APA, all rights reserved). PMID:25730725

  19. Omni-directional L-band antenna for mobile communications

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  20. More About Lens Antenna For Mobile/Satellite Communication

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  1. 78 FR 56737 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-13

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

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

    NASA Technical Reports Server (NTRS)

    Golshan, Nasser

    1993-01-01

    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.

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

    E-print Network

    Vardoulias, George

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

  4. Development of a mobile research flight test support capability

    NASA Technical Reports Server (NTRS)

    Rhea, Donald C.; Moore, Archie L.

    1988-01-01

    This paper presents the approach taken by the NASA Western Aeronautical Test Range (WATR) of the Ames Research Center (ARC) to develop and utilize mobile systems to satisfy unique real-time research flight test requirements of research projects such as the advanced fighter technology integration (AFTI) F-16, YAV-8B Harrier, F-18 high-alpha research vehicle (HARV), XV-15, and the UH-60 Black Hawk. The approach taken is cost-effective, staff efficient, technologically current, and provides a safe and effective research flight test environment to support a highly complex set of real-time requirements including the areas of tracking and data acquisition, communications (audio and video) and real-time processing and display, postmission processing, and command uplink. The development of this capability has been in response to the need for rapid deployment at varied site locations with full real-time comutation and display capability. This paper will discuss the requirements, implementation and growth plan for mobile systems development within the NASA Western Aeronautical Test Range.

  5. Development of a mobile research flight test support capability

    NASA Technical Reports Server (NTRS)

    Rhea, Donald C.; Moore, Archie L.

    1988-01-01

    This paper presents the approach taken by the NASA Western Aeronautical Test Range (WATR) of the Ames Research Center to develop and utilize mobile systems to satisfy unique real-time research flight test requirements of research projects such as the advanced fighter technology integration (AFTI)F-16, YAV-8B Harrier, F-18 high-alpha research vehicle (HARV), XV-15, and the UH-60 Black Hawk. The approach taken is cost-effective, staff efficient, technologically current, and provides a safe and effective research flight test environment to support a highly complex set of real-time requirements including the areas of tracking and data acquisition, communications (audio and video) and real-time processing and display, postmission processing, and command uplink. The development of this capability has been in response to the need for rapid deployment at varied site locations with full real-time computations and display capability. This paper will discuss the requirements, implementation and growth plan for mobile systems development within the NASA Western Aeronautical Test Range.

  6. Smart Antenna Application in DS-CDMA Mobile Communication System

    NASA Astrophysics Data System (ADS)

    Ng, Kok K.

    2002-09-01

    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.

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

    E-print Network

    Talbot, James P.

    Mobile Communications for Medical Care a study of current and future healthcare and health Communications for Medical Care ­ Final Report 2 21 April 2011 #12;Mobile Communications for Medical Care a study Programme 113 References 119 #12;Mobile Communications for Medical Care ­ Final Report 4 21 April 2011 #12

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

    NASA Astrophysics Data System (ADS)

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

    2005-07-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  10. Robust Timing Synchronization in Aeronautical Mobile Communication Systems

    NASA Technical Reports Server (NTRS)

    Xiong, Fu-Qin; Pinchak, Stanley

    2004-01-01

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

  11. Location-Based Adaptive Mobile Learning Research Framework and Topics

    Microsoft Academic Search

    Qing Tan; Kinshuk; Yen-hung Kuo; Yu-lin Jeng; Po-han Wu; Yueh-min Huang; Tzu-chien Liu; Maiga Chang

    2009-01-01

    Location-based adaptive mobile learning utilizes a unique feature: location awareness of mobile devices in regards to other online learning to implement location-based functionalities or features to create adaptive and collaborative learning in mobile learning environment. There are many important research issues and technical challenges in the location-based adaptive mobile learning systems, including the assessment of learning in the mobile environment.

  12. RESEARCH ON A DISTRIBUTED ARCHITECTURE OF MOBILE GIS BASED ON WAP

    Microsoft Academic Search

    Wang Fangxiong; Jiang Zhiyong

    Mobile Geographical Information System (Mobile GIS) is a Geographical Information System based on mobile computing and mobile Internet. It is not a conventional GIS modified to operate on a smaller computer, but an extension of Web GIS to mobile Internet including wireless Internet\\/Intranet and mobile communication network. But architectures of Web GIS are unsuitable for Mobile GIS, because of several

  13. Assessing mobile phone communication utility preferences in a social support network

    Microsoft Academic Search

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

    2010-01-01

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

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

    Microsoft Academic Search

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

    2002-01-01

    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

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

    Microsoft Academic Search

    LAL C. GODARA

    1997-01-01

    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

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

    ERIC Educational Resources Information Center

    Beaubrun, Ronald; Pierre, Samuel

    2001-01-01

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

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

    E-print Network

    Carlini, David

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

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

    E-print Network

    Aloul, Fadi

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

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

    Microsoft Academic Search

    Fujun Lai; Joe Hutchinson; Dahui Li; Changhong Bai

    2007-01-01

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

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

    E-print Network

    Krishnamurthy, Srikanth

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

  1. An Ethical Perspective to Communication Research.

    ERIC Educational Resources Information Center

    Hochheimer, John L.

    Despite widespread indifference or resistence to the idea, communication scientists need to discuss the ethical implications of their research. Fortunate in being able to conduct research, scientists are responsible to and for the larger population in whose names they do their work. They need to realize that such traditional research areas and…

  2. Two-Armed, Mobile, Sensate Research Robot

    NASA Technical Reports Server (NTRS)

    Engelberger, J. F.; Roberts, W. Nelson; Ryan, David J.; Silverthorne, Andrew

    2004-01-01

    The Anthropomorphic Robotic Testbed (ART) is an experimental prototype of a partly anthropomorphic, humanoid-size, mobile robot. The basic ART design concept provides for a combination of two-armed coordination, tactility, stereoscopic vision, mobility with navigation and avoidance of obstacles, and natural-language communication, so that the ART could emulate humans in many activities. The ART could be developed into a variety of highly capable robotic assistants for general or specific applications. There is especially great potential for the development of ART-based robots as substitutes for live-in health-care aides for home-bound persons who are aged, infirm, or physically handicapped; these robots could greatly reduce the cost of home health care and extend the term of independent living. The ART is a fully autonomous and untethered system. It includes a mobile base on which is mounted an extensible torso topped by a head, shoulders, and two arms. All subsystems of the ART are powered by a rechargeable, removable battery pack. The mobile base is a differentially- driven, nonholonomic vehicle capable of a speed >1 m/s and can handle a payload >100 kg. The base can be controlled manually, in forward/backward and/or simultaneous rotational motion, by use of a joystick. Alternatively, the motion of the base can be controlled autonomously by an onboard navigational computer. By retraction or extension of the torso, the head height of the ART can be adjusted from 5 ft (1.5 m) to 6 1/2 ft (2 m), so that the arms can reach either the floor or high shelves, or some ceilings. The arms are symmetrical. Each arm (including the wrist) has a total of six rotary axes like those of the human shoulder, elbow, and wrist joints. The arms are actuated by electric motors in combination with brakes and gas-spring assists on the shoulder and elbow joints. The arms are operated under closed-loop digital control. A receptacle for an end effector is mounted on the tip of the wrist and contains a force-and-torque sensor that provides feedback for force (compliance) control of the arm. The end effector could be a tool or a robot hand, depending on the application.

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

    E-print Network

    Diaz-Guilera, Albert

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

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

    E-print Network

    Jiang, Hai

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

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

    E-print Network

    California at San Diego, University of

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

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

    E-print Network

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

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

    E-print Network

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

  8. 23 M-Learning: The Educational Use of Mobile Communication Devices

    Microsoft Academic Search

    Paul Birevu Muyinda; Ezra Mugisa; Kathy Lynch

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

  9. Optimized Communication using the SOAP Infoset For Mobile Multimedia Collaboration Applications

    E-print Network

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

  10. 76 FR 58537 - In the Matter of Certain Personal Data and Mobile Communications Devices and Related Software...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-21

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

  11. 77 FR 40399 - Qiao Xing Universal Resources, Inc., and Qiao Xing Mobile Communication Co., Ltd.; Order of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-09

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

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

    Microsoft Academic Search

    Sz Jie Sung

    2011-01-01

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

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

    Microsoft Academic Search

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

    2006-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Salmasi, Allen

    1988-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Jensen, Michael A.; Rahmat-Samii, Yahya

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

  16. Speech coding at 4800 bps for mobile satellite communications

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  17. Considerations of digital phase modulation for narrowband satellite mobile communication

    NASA Technical Reports Server (NTRS)

    Grythe, Knut

    1990-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Jensen, Michael A.; Rahmat-Samii, Yahya

    1993-01-01

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

  19. Adaptive beamforming in a CDMA mobile satellite communications system

    NASA Technical Reports Server (NTRS)

    Munoz-Garcia, Samuel G.

    1993-01-01

    Code-Division Multiple-Access (CDMA) stands out as a strong contender for the choice of multiple access scheme in these future mobile communication systems. This is due to a variety of reasons such as the excellent performance in multipath environments, high scope for frequency reuse and graceful degradation near saturation. However, the capacity of CDMA is limited by the self-interference between the transmissions of the different users in the network. Moreover, the disparity between the received power levels gives rise to the near-far problem, this is, weak signals are severely degraded by the transmissions from other users. In this paper, the use of time-reference adaptive digital beamforming on board the satellite is proposed as a means to overcome the problems associated with CDMA. This technique enables a high number of independently steered beams to be generated from a single phased array antenna, which automatically track the desired user signal and null the unwanted interference sources. Since CDMA is interference limited, the interference protection provided by the antenna converts directly and linearly into an increase in capacity. Furthermore, the proposed concept allows the near-far effect to be mitigated without requiring a tight coordination of the users in terms of power control. A payload architecture will be presented that illustrates the practical implementation of this concept. This digital payload architecture shows that with the advent of high performance CMOS digital processing, the on-board implementation of complex DSP techniques -in particular digital beamforming- has become possible, being most attractive for Mobile Satellite Communications.

  20. Incorporating guidelines for use of mobile technologies in health research and practice.

    PubMed

    Young, Sean D; Holloway, Ian W; Swendeman, Dallas

    2014-06-01

    This commentary aims to create initial recommendations to guide researchers' decisions on the development and use of mobile technologies for public health research. We recommend that mobile technologies for public health research should be scalable and sustainable; draw on social, psychological and/or behavioral theoretical models; be able to be integrated with multiple communication devices; incorporate social network and/or geographic metrics and take a community-based participatory approach to development and implementation. All of these approaches are discussed. PMID:24713154

  1. Downsizing Antenna Technologies for Mobile and Satellite Communications

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

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

    E-print Network

    Ansari, Nirwan

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

  3. The research of mobile application user experience and assessment model

    Microsoft Academic Search

    Zhi Chen; Shangshang Zhu

    2011-01-01

    This essay mainly study mobile application user experience and quantitative assessment through Analytic Hierarchy Process. On the basis of the relational studies, this paper put forward four-dimensional assessment system of mobile application user experience. That is: user characteristics, App properties, App system supports and context parameters. What's more, combining user research, paper offers a comprehensive hierarchy criterion framework for mobile

  4. Mobile social signal processing: vision and research issues

    Microsoft Academic Search

    Alessandro Vinciarelli; Roderick Murray-Smith; Hervé Bourlard

    2010-01-01

    This paper introduces the First International Workshop on Mobile Social Signal Processing (SSP). The Workshop aims at bringing together the Mobile HCI and Social Signal Processing research communities. The former investigates approaches for effective interaction with mobile and wearable devices, while the latter focuses on modeling, analysis and synthesis of nonverbal behavior in human{human and human-machine interactions. While dealing with

  5. Theoretical and Research Issues in Black Communication.

    ERIC Educational Resources Information Center

    Smith, Arthur L.

    There has been little research on the communicative behaviors of Afro-Americans, whose language and public messages rarely fit into traditional patterns of Anglo-Saxon discourse. Intensive study is warranted in numerous areas. One is the area of linguistic continuity research, which investigates similarities in vocabulary and expression between…

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

    E-print Network

    Blake, Edwin

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

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

    E-print Network

    Mostofi, Yasamin

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

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

    E-print Network

    Paris-Sud XI, Université de

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

  9. A Review of Research on Mobile Learning in Teacher Education

    ERIC Educational Resources Information Center

    Baran, Evrim

    2014-01-01

    Mobile devices have become attractive learning devices for education. While the majority of the existing research has focused primarily on the value of mobile learning for students, researchers have recently started exploring its potentials within teacher development. The present qualitative synthesis of quantitative and qualitative research aimed…

  10. The Need for Research on Mobile Technologies for

    E-print Network

    Wobbrock, Jacob O.

    that there needs to be more research on technologies for people with low-vision. While the vast majority of people argue that there needs to be more research on mobile technologies for people with LV who can utilizeThe Need for Research on Mobile Technologies for People with Low-Vision Abstract We argue

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

    PubMed

    McNaughton, David; Light, Janice

    2013-06-01

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

  12. Evolution of the Inmarsat mobile satellite communications system into the coming decade

    NASA Astrophysics Data System (ADS)

    Lundberg, O.

    1982-09-01

    Future developments of the Inmarsat mobile satellite communications system are discussed, and a brief background is given. Particular uses for such satellites include sea distress communications, efficiency and management of ships, and maritime public correspondence services. In order to meet projected capacity requirements, research is being done in the areas of multiple transponders, spot beams covering high traffic concentration ocean areas, digital modulation, and L-to-L band transponders for search and rescue coordination. It is found that a spacecraft with a capacity in the range of 125-250 channels will be necessary, and that coverage should be extended to a polar orbiting system. In order to achieve these goals, institutional and financial issues must be resolved.

  13. Domestic mobile satellite communication system using 2.6/2.5 GHz band

    NASA Astrophysics Data System (ADS)

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

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

  14. Research on mobile GIS based on LBS

    Microsoft Academic Search

    Feixiang Chen; Chongjun Yang; Wenyang Yu; Xiaoqiu Le; Jianyu Yang

    2005-01-01

    Mobile computing system based on personal digital assistant (PDA) products has been used widely, and location-based service (LBS) is one of the most promising application directions of GIS. It is important to integrate the mobile computing technology and GIS technology to meet the need of LBS. The purpose of the paper is to propose a solution of mobile GIS based

  15. Using satellite communications for a mobile computer network

    NASA Technical Reports Server (NTRS)

    Wyman, Douglas J.

    1993-01-01

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

  16. Research in space commercialization, technology transfer, and communications, volume 2

    NASA Technical Reports Server (NTRS)

    Dunn, D. A.; Agnew, C. E.

    1983-01-01

    Spectrum management, models for evaluating communication systems, the communications regulatory environment, expert prediction and consensus, remote sensing, and manned space operations research are discussed.

  17. Adaptive digital beamforming for a CDMA mobile communications payload

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

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

    PubMed Central

    Elangovan, R; Arulchelvan, S

    2013-01-01

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

  19. Directedness of information flow in mobile phone communication networks

    E-print Network

    Peruani, Fernando; 10.1371/journal.pone.0028860

    2013-01-01

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

  20. David Florida Laboratory: Support for mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Dumoulin, Jean-Guy; Mamen, Rolf

    1995-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

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

  2. The Human Communication Research Centre Dialogue Database.

    ERIC Educational Resources Information Center

    Anderson, Anne H.; And Others

    1992-01-01

    Describes the Human Communication Research Centre Dialogue Database. The database consists of over 700 transcribed and coded dialogues from pairs of speakers aged from 7-14. The speakers are recorded over 2 years while tackling cooperative problem-solving tasks, and the same pairs of speakers are recorded over 2 years tackling 10 different…

  3. Michigan Center for Health Communications Research

    Cancer.gov

    Michigan Center for Health Communications Research Presented by: Victor J. Strecher, PhD, MPH Principal Investigator OUR GOAL Cost The goal: The goal: High efficacy High reach Cost High reach High efficacy eHealth “We are truly entering a new age

  4. Fisheries Research 63 (2003) 275282 Short communication

    E-print Network

    Cooke, Steven J.

    study using larger species of fish that are commonly landed using these gear types. © 2003 Elsevier; Gear effects 1. Introduction Landing nets are commonly used by recreational anglers to aidFisheries Research 63 (2003) 275­282 Short communication Effects of landing net mesh type on injury

  5. Communication Network Research: An Examination of Controversies

    Microsoft Academic Search

    Alvin M. Snadowsky

    1972-01-01

    This study was concerned with the salient issues in communication network research. When the organizational phase was separated from the operational phase of problem-solving, centralization was adequate in both phases where the probems were simple symbol identification tasks. Although a centralized operational procedure also was adopted by all groups solving complex arithmetic tasks, the decentralized network permitted the organizational flexibility

  6. Autonomous mobile robot research using the HERMIES-III robot

    SciTech Connect

    Pin, F.G.; Beckerman, M.; Spelt, P.F.; Robinson, J.T.; Weisbin, C.R.

    1989-01-01

    This paper reports on the status and future directions in the research, development and experimental validation of intelligent control techniques for autonomous mobile robots using the HERMIES-III robot at the Center for Engineering Systems Advanced research (CESAR) at Oak Ridge National Laboratory (ORNL). HERMIES-III is the fourth robot in a series of increasingly more sophisticated and capable experimental test beds developed at CESAR. HERMIES-III is comprised of a battery powered, onmi-directional wheeled platform with a seven degree-of-freedom manipulator arm, video cameras, sonar range sensors, laser imaging scanner and a dual computer system containing up to 128 NCUBE nodes in hypercube configuration. All electronics, sensors, computers, and communication equipment required for autonomous operation of HERMIES-III are located on board along with sufficient battery power for three to four hours of operation. The paper first provides a more detailed description of the HERMIES-III characteristics, focussing on the new areas of research and demonstration now possible at CESAR with this new test-bed. The initial experimental program is then described with emphasis placed on autonomous performance of human-scale tasks (e.g., valve manipulation, use of tools), integration of a dexterous manipulator and platform motion in geometrically complex environments, and effective use of multiple cooperating robots (HERMIES-IIB and HERMIES- III). The paper concludes with a discussion of the integration problems and safety considerations necessarily arising from the set-up of an experimental program involving human-scale, multi-autonomous mobile robots performance. 10 refs., 3 figs.

  7. Research of intelligent recommendation for mobile reading

    NASA Astrophysics Data System (ADS)

    Li, Qu

    2013-07-01

    Mobile reading is the trend of current publishing industry. Intelligent Recommendation system is useful and profitable for mobile reading platforms. Currently, intelligent recommendation systems mainly focus on news recommendation or production recommendation in e-commerce. In this paper, we designed and implemented an intelligent recommendation system based on slope one algorithm. Results show that our algorithm can help the users to find their interested books and thus greatly improve the income of mobile reading platform.

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

    NASA Astrophysics Data System (ADS)

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

    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.

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

    Microsoft Academic Search

    Ingo Vogelsang

    2010-01-01

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

  10. Enforcement of Communications Policies in Software Agent Systems through Mobile Code

    Microsoft Academic Search

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

    2003-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

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

    Microsoft Academic Search

    D. Cox; D. Reudink

    1972-01-01

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

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

    Microsoft Academic Search

    LAL C. GODARA

    1997-01-01

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

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

    E-print Network

    Levy, Hanoch

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

  15. Phased Arrays of Ground and Airborne Mobile Terminals for Satellite Communications

    NASA Technical Reports Server (NTRS)

    Huang, John

    1996-01-01

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

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

    ERIC Educational Resources Information Center

    Norris, Daniel T.

    2007-01-01

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

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

    E-print Network

    Waterloo, University of

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

  18. Human mobility models and opportunistic communications system design

    Microsoft Academic Search

    Pan Hui; Jon Crowcroft

    2008-01-01

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

  19. A Survey of Routing Techniques for Mobile Communications Networks

    Microsoft Academic Search

    S. Ramanathan; Martha Steenstrup

    1996-01-01

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

  20. Motivations for using the mobile phone for mass communications and entertainment

    Microsoft Academic Search

    Ran Wei

    2008-01-01

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

  1. Federal research and development for satellite communications

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A Committee on Satellite Communication (COSC) was formed under the auspices of the Space Applications Board (SAB) in order to study Federal research and development on satellite communications (SC). Discussion on whether to continue the research and development and the proper role of the Federal Government are addressed. Discussion focussed on six possible options for a Federal role in SC research and development: (1) the current NASA SC program; (2) an expanded NASA SC technology program; (3) a SC technology flight test support program; (4) an experimental SC technology flight program; (5) an experimental public service SC system program; and (6) an operational public service SC system program. Decision criteria and recommendations are presented.

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

    PubMed

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

    2014-01-01

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

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

    PubMed Central

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

    2014-01-01

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

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

    Microsoft Academic Search

    Liu Jun; Zhao Hui

    2010-01-01

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

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

    E-print Network

    Paris-Sud XI, Université de

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

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

    Microsoft Academic Search

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

    2008-01-01

    Motivation and pressure are considered two factors impacting vocational senior high school student learning. New communication technology, especially mobile communication technology, is supposed to be effective in encouraging 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.

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

    E-print Network

    Wang, Cheng-Xiang

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

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

    ERIC Educational Resources Information Center

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

    2008-01-01

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

  9. Children's Literature in the Undergraduate Course on Communication Research Methods

    ERIC Educational Resources Information Center

    Brown, Daniel S.

    2010-01-01

    Objective: Students will develop positive attitudes toward communication research by linking new values and principles with the familiar values and principles contained in children's literature. Course: Communication Research Methods.

  10. Transportation and Aging: A Research Agenda for Advancing Safe Mobility

    ERIC Educational Resources Information Center

    Dickerson, Anne E.; Molnar, Lisa J.; Eby, David W.; Adler, Geri; Bedard, Michel; Berg-Weger, Marla; Classen, Sherrilene; Foley, Daniel; Horowitz, Amy; Kerschner, Helen; Page, Oliver; Silverstein, Nina M.; Staplin, Loren; Trujillo, Leonard

    2007-01-01

    Purpose: We review what we currently know about older driver safety and mobility, and we highlight important research needs in a number of key areas that hold promise for achieving the safety and mobility goals for the aging baby boomers and future generations of older drivers. Design and Methods: Through the use of a framework for transportation…

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

    PubMed

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

    2013-01-01

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

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

    PubMed Central

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

    2013-01-01

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

  13. Optimization of Wireless Resources for Personal Communications Mobility Tracking*

    E-print Network

    Steiglitz, Kenneth

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

  14. On the design of security protocols for mobile communications

    Microsoft Academic Search

    Yi Mu; Vijay Varadharajan

    1996-01-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    E-print Network

    Latchman, Haniph A.

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

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

    NASA Technical Reports Server (NTRS)

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

    1982-01-01

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

  18. Research Integrity in Communication Sciences and Disorders.

    PubMed

    Moss, Sharon E

    2010-11-16

    PURPOSE: A joint program on "research on research integrity" sponsored by the National Institute of Neurological Disorders and Stroke (NINDS) and the Office of Research Integrity (ORI) encouraged the examination of practices and policies promoting the responsible conduct of research (RCR). Our grant, Research Integrity in ASHA: Education and Publication (#NS44534), enabled ASHA's Research Integrity Grant Group (a) to identify patterns of teaching and learning in communication sciences and disorders graduate programs about specific topics of research integrity on the conduct of science, (b) to examine perceptions about concepts of research integrity as they apply to scientific journals within the discipline, and (c) to evaluate policies and practices established by ASHA to protect the integrity of published scientific work. METHOD: Historical and contemporary literature were reviewed, surveys were conducted, and ASHA policies were analyzed. CONCLUSION: This JSLHR supplement has been written with the aim of informing and inspiring scientists, students, research institutions, and professional societies to practice responsible research in the 21st century and beyond. PMID:21081678

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  20. Mobile and Ubiquitous Computing Cellular Mobile and Implications of Mobility

    E-print Network

    Roussos, George

    in More Depth · Wireless communication ­ Dis.roussos@dcs.bbk.ac.uk Session Overview · How cellular mobile systems work ­ Elements ­ Methods · Implications of mobility for computing ­ Wireless ­ Mobility ­ Portability · Research in 1960's and 1970's at Bell Labs led

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

    Microsoft Academic Search

    LIU Jun

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

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

    Microsoft Academic Search

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

    2005-01-01

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

  3. Prospects for Technical Communication: Research for Futures Needs.

    ERIC Educational Resources Information Center

    Mathes, J. C.

    The need for technical communication to enable the transition from a "postindustrial" future to an alternative future is incalculable; however, research is required to improve current technical communication models and methods. The current rhetoric of technical communication derives from an inadequate command-generated technical communication

  4. The Institute for Communication Research Annual Report 1975-1976.

    ERIC Educational Resources Information Center

    Stanford Univ., CA. Inst. for Communication Research.

    This document summarizes projects and and research activities for the year 1975-1976 in five areas: (1) international communication, (2) health communication; (3) communication technology and public policy; (4) communication and media; and (5) information needs and uses. Specific activities discussed pertain to educational development and…

  5. A Theory and Research Oriented Communication Major: Communication Studies.

    ERIC Educational Resources Information Center

    Redmond, Mark V.; Waggoner, David W.

    1992-01-01

    Discusses the four principles that guided the development of the communication studies program at Iowa State University. Describes the proposed program in communication studies. Appends the proposed curriculum. (RS)

  6. For Immediate Release --Wednesday, October 30, 2013 University of Lethbridge researchers study if mobile app

    E-print Network

    Seldin, Jonathan P.

    of Lethbridge researchers study if mobile app improves decision-making A research of surgery. "Using information gathered from textbooks or the mobile app, nurses an application installed on their mobile phones that contains a wealth of medical

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

    NASA Astrophysics Data System (ADS)

    Ristau, Henry

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

  8. Keep on Movin'? Research Mobility's Meanings for Italian Early-Stage Researchers

    ERIC Educational Resources Information Center

    Carrozza, Chiara; Minucci, Sara

    2014-01-01

    Research mobility is a core notion for the European Research Area (ERA), and a wide body of literature has focused on the factors facilitating and hindering researchers' mobility. The European discourse tends to promote mobility as a value, but to what extent is it perceived as such by researchers? What role does mobility play in career…

  9. The Mobile Agents Integrated Field Test: Mars Desert Research Station April 2003

    NASA Technical Reports Server (NTRS)

    Clancey, William J.; Sierhuis, Maarten; Alena, Rick; Crawford, Sekou; Dowding, John; Graham, Jeff; Kaskiris, Charis; Tyree, Kim S.; vanHoof, Ron

    2003-01-01

    The Mobile Agents model-based, distributed architecture, which integrates diverse components in a system for lunar and planetary surface operations, was extensively tested in a two-week field "technology retreat" at the Mars Society s Desert Research Station (MDRS) during April 2003. More than twenty scientists and engineers from three NASA centers and two universities refined and tested the system through a series of incremental scenarios. Agent software, implemented in runtime Brahms, processed GPS, health data, and voice commands-monitoring, controlling and logging science data throughout simulated EVAs with two geologists. Predefined EVA plans, modified on the fly by voice command, enabled the Mobile Agents system to provide navigation and timing advice. Communications were maintained over five wireless nodes distributed over hills and into canyons for 5 km; data, including photographs and status was transmitted automatically to the desktop at mission control in Houston. This paper describes the system configurations, communication protocols, scenarios, and test results.

  10. Recasting Communication Theory and Research: A Cybernetic Approach.

    ERIC Educational Resources Information Center

    Hill, Gary A.

    The author's main concern is to provide a research format which will supply a unitary conception of communication. The wide range of complex topics and variety of concepts embraced by communication theory and the rather disparate set of phenomena encompassed by communication research create this need for a unitary study approach capable of linking…

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

    E-print Network

    Miritello, Giovanna; Lara, Rubén; Martínez-López, Rocío; Roberts, Sam G B; Dunbar, Robin I M

    2013-01-01

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

  12. On supporting handoff management for multi-source video streaming in mobile communication systems

    Microsoft Academic Search

    Tarik Taleb; Tomoyuki Nakamura; Kazuo Hashimoto

    2008-01-01

    Video streaming to mobile users is gaining momentum within the communities of both industrial and academic researchers. In a previous research work, the authors proposed a multi-source streaming method for video streaming to mobile users. The focus was on video fragmentation and packet scheduling to avoid packet reordering and packet redundancy. As a continuation to the work, this paper presents

  13. Estimation of the demand for public services communications. [market research and economic analysis for a communications satellite system

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Market analyses and economic studies are presented to support NASA planning for a communications satellite system to provide public services in health, education, mobile communications, data transfer, and teleconferencing.

  14. Research the mobile phone operation interfaces for vision-impairment.

    PubMed

    Yao, Yen-Ting; Leung, Cherng-Yee

    2012-01-01

    Due to the vision-impaired users commonly having difficulty with mobile-phone function operations and adaption any manufacturer's user interface design, the goals for this research are established for evaluating how to improve for them the function operation convenience and user interfaces of either mobile phones or electronic appliances in the market currently. After applying collecting back 30 effective questionnaires from 30 vision-impairment, the comments have been concluded from this research include: (1) All mobile phone manufactures commonly ignorant of the vision-impairment difficulty with operating mobile phone user interfaces; (2) The vision-impairment preferential with audio alert signals; (3) The vision-impairment incapable of mobile-phone procurement independently unless with assistance from others; (4) Preferential with adding touch-usage interface design by the vision-impairment; in contrast with the least requirement for such functions as braille, enlarging keystroke size and diversifying-function control panel. With exploring the vision-impairment's necessary improvements and obstacles for mobile phone interface operation, this research is established with goals for offering reference possibly applied in electronic appliance design and . Hopefully, the analysis results of this research could be used as data references for designing electronic and high-tech products and promoting more usage convenience for those vision-impaired. PMID:22317456

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

    NASA Astrophysics Data System (ADS)

    Marcus, Aaron

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

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

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

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

  17. Military Communications Satellite System Multiplies UHF Channel Capacity for Mobile Users

    Microsoft Academic Search

    Z. Wadsworth

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

  18. Mobile Database Application Research Based on GIS

    Microsoft Academic Search

    Weibo Li; Hong Yang; Ping He

    2008-01-01

    This article discussed many problems which exist in the process of realizing GIS datapsilas synchronization based on the characteristics of GIS spatio-temporal data and mobile database, such as how to improve the efficiency of data visiting and updating and guaranteeing data transmissionpsilas reliability and uniformity and so on, proposed the multithread technology, three-layer duplication\\/buffer architecture, conflict detection mechanism and GIS

  19. Human factor research of voice search on mobile internet

    Microsoft Academic Search

    Kewei Yuan; Wenjun Hou; Yujia Zhao

    2008-01-01

    Voice search is a kind of promising search approach in the era of mobile internet. Currently, most of voice search services are still manual work, which are expected to be replaced by human-machine voice search based on voice recognition technology. Despite numerous disadvantages of human-human voice search, its interaction approach as natural language communication is obviously superior to human-machine voice

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1992-03-01

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

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

    E-print Network

    Howard, Sheryl

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

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

    E-print Network

    Marti, Stefan Johannes Walter, 1965-

    2005-01-01

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

  4. Autonomous Mobile Robot Research Using The Hermies-III Robot

    Microsoft Academic Search

    F. G. Pin; M. Beckerman; P. F. Spelt; J. T. Robinson; C. R. Weisbin

    1989-01-01

    This paper reports on the status and future directions in the research, development and experimental validation of intelligent control techniques for autonomous mobile robots using the HERMIES-111 robot at the Center for Engineering Systems Advanced Research (CESAR) at Oak Ridge National Laboratory (ORNL). HERMIES-I11 is the fourth robot in a series of increasingly more sophisticated and capable experimental test beds

  5. Action Research Approach on Mobile Learning Design for the Underserved

    ERIC Educational Resources Information Center

    Kim, Paul H.

    2009-01-01

    This paper discusses an action research study focused on developing a mobile learning model of literacy development for underserved migrant indigenous children in Latin America. The research study incorporated a cyclical action model with four distinctive stages (Strategize, Apply, Evaluate, and Reflect) designed to guide constituencies involved…

  6. 2005 Mobility of Transfer Students in BC. Research Results

    ERIC Educational Resources Information Center

    Holubeshen, Moufida; Cowin, Bob; Gaber, Devron

    2006-01-01

    This 8-page document outlines the key findings of research conducted to assess the number and proportion of potential transfer students from Fall 2004 who subsequently registered at BC universities in 2005, as well as the mobility patterns of these students among all public post-secondary institutions in BC. The research was initiated to assist BC…

  7. A communication protocol for mobile satellite systems affected by rain attenuation

    NASA Technical Reports Server (NTRS)

    Lay, Norman; Dessouky, Khaled

    1992-01-01

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

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

    Microsoft Academic Search

    Bernard Sklar

    1997-01-01

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

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

    E-print Network

    Loyka, Sergey

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

  10. 75 FR 17434 - In the Matter of Certain Personal Data and Mobile Communications Devices and Related Software...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-06

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

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

    Microsoft Academic Search

    T. Okuda; T. Ideguchi; X. Tian

    2004-01-01

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

  12. Business Communication Consulting and Research in Multinational Companies.

    ERIC Educational Resources Information Center

    Hildebrandt, Herbert W.

    1978-01-01

    Describes three issues involved in communication research and consulting for multinational companies, particularly those in Germany: qualifications for doing international consulting and research, problems of American scholar-researchers in those firms, and suggestions for dealing with those issues. (JMF)

  13. Satellite Communications for Aeronautical Applications: Recent research and Development Results

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.

    2001-01-01

    Communications systems have always been a critical element in aviation. Until recently, nearly all communications between the ground and aircraft have been based on analog voice technology. But the future of global aviation requires a more sophisticated "information infrastructure" which not only provides more and better communications, but integrates the key information functions (communications, navigation, and surveillance) into a modern, network-based infrastructure. Satellite communications will play an increasing role in providing information infrastructure solutions for aviation. Developing and adapting satellite communications technologies for aviation use is now receiving increased attention as the urgency to develop information infrastructure solutions grows. The NASA Glenn Research Center is actively involved in research and development activities for aeronautical satellite communications, with a key emphasis on air traffic management communications needs. This paper describes the recent results and status of NASA Glenn's research program.

  14. Highly Efficient Digital Mobile Communications with a Linear Modulation Method

    Microsoft Academic Search

    YOSHIHIKO AKAIWA; Y. Nagata

    1987-01-01

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

  15. Acculturation and Communicative Mobility Among Former Soviet Nationalities.

    ERIC Educational Resources Information Center

    Haarmann, Harald; Holman, Eugene

    1997-01-01

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

  16. Channel Modeling and Simulation in Satellite Mobile Communication Systems

    Microsoft Academic Search

    Branka Vucetic; Jun Du

    1992-01-01

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

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

    Microsoft Academic Search

    Rakshit Negi

    2009-01-01

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

  18. Performance evaluation of mobile wireless communication systems with link adaptation

    Microsoft Academic Search

    Felipe A. Cruz-Pérez; Genaro Hernández-Valdez; Lauro Ortigoza-Guerrero

    2003-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

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

    E-print Network

    Peha, Jon M.

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

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

    Microsoft Academic Search

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

    1991-01-01

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

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

    E-print Network

    Mochizuki, Yujiro, 1973-

    2006-01-01

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

  3. Mobile systems; From chaos to convergence

    NASA Astrophysics Data System (ADS)

    Swain, R. S.

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

  4. Future directions in communication research: individual health behaviors and the influence of family communication.

    PubMed

    Baiocchi-Wagner, Elizabeth A

    2015-08-01

    Although numerous fields continue to advance research toward various areas of health prevention, communication researchers have yet to examine fully the link between communication and health improvement. This is particularly true of those studying the intersections of family and health communication-unfortunate, given that family members serve as primary socialization agents in health attitudes and behaviors. Using the example of obesity-related health behaviors, the following essay advances the argument that continued research aimed at understanding the intersection of health and families' communicative influence may help to illuminate the nature, causes, and redress to health issues that are correlated with individual health practices. This is accomplished by (a) reviewing contributions and limitations of pioneering studies in (family) health literature and (b) offering three key research areas for health communication exploration that will move scholars toward communication-based solutions (e.g., family-level communication health interventions). PMID:24837245

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

    Microsoft Academic Search

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

    2007-01-01

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

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

    E-print Network

    Farritor, Shane

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

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

    E-print Network

    Dong, Liang

    Cross Layer Design for Mobile Ad-Hoc Unmanned Aerial Vehicle Communication Networks Abdel Ilah of the Unmanned Aerial Vehicle (UAV) Ad-Hoc net- work, the layered architecture is not flexible enough to achieve for Unmanned Aerial Vehicle (IMAC UAV). As for the routing protocol, We developed the Optimized Link State

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

    E-print Network

    Jiang, Hai

    WIRELESS COMMUNICATIONS AND MOBILE COMPUTING Wirel. Commun. Mob. Comput. 2009; 9:705­717 Published, , Shaohua Wu2 and Naitong Zhang2 1 Department of Electrical and Computer Engineering, University of Alberta of Electrical and Computer Engineering, University of Alberta, Canada. E-mail: hai

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

    E-print Network

    Shen, Xuemin "Sherman"

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

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

    Microsoft Academic Search

    Vicent Pla; Vicente Casares Giner

    2005-01-01

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

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

    ERIC Educational Resources Information Center

    Chaiprasurt, Chantorn; Esichaikul, Vatcharaporn

    2013-01-01

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

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

    Microsoft Academic Search

    T. Kahwa; N. Georganas

    1978-01-01

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

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

    Microsoft Academic Search

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

    1982-01-01

    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

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

    ERIC Educational Resources Information Center

    Jones, Geraldine; Edwards, Gabriele; Reid, Alan

    2009-01-01

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

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

    Microsoft Academic Search

    Yuping Zhao; Sven-Gustav Häggman

    2001-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Han, Guodong; Wang, Jiazhen

    2005-11-01

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

  17. Eye Contact Communication System between Mobile Robots Using Invisible Code Display

    E-print Network

    Paris-Sud XI, Université de

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

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

    E-print Network

    Neimark, Alexander V.

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

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

    Microsoft Academic Search

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

    1993-01-01

    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

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

    Microsoft Academic Search

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

    1993-01-01

    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

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

    Microsoft Academic Search

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

    1992-01-01

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

  2. DESIGN AND IMPLEMENTATION OF A CDMA TRANSMITTER FOR MOBILE CELLULAR COMMUNICATIONS

    Microsoft Academic Search

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

    2001-01-01

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

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

    Microsoft Academic Search

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

    1991-01-01

    The communication channel between the MARECS satellite at 26 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

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

    Microsoft Academic Search

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

    1996-01-01

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

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

    Microsoft Academic Search

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

    1991-01-01

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

  6. Student as Communication Skills Trainer: From Research to "Concept Keys"

    ERIC Educational Resources Information Center

    Bodie, Graham D.

    2008-01-01

    Although textbooks are filled with practical communication advice, many students overlook the importance of basing practical advice about communication on quality research. This oversight is important for two reasons. First, given the explosion of self-help remedies focused on communication, students should learn to distinguish between…

  7. Management Communication Ethics Research: Finding the Bull's-Eye.

    ERIC Educational Resources Information Center

    Reinsch, N. Lamar, Jr.

    1996-01-01

    Argues that scholars who wish to produce substantive research in management communication ethics would be helped by a clear vision of what the term designates. States that management communication ethics should designate concerns that lie at the intersection of management, communication, and ethics. Concludes that this approach could help to…

  8. Human Communication Research ISSN 0360-3989 ORIGINAL ARTICLE

    E-print Network

    Sprott, Julien Clinton

    ­396 © 2010 International Communication Association #12;M.-L. Mares & Y. Sun TV & Aging Age differencesHuman Communication Research ISSN 0360-3989 ORIGINAL ARTICLE The Multiple Meanings of Age for Television Content Preferences Marie-Louise Mares1 & Ye Sun2 1 Department of Communication Arts, University

  9. Defining Moments in Risk Communication Research: 1996–2005

    Microsoft Academic Search

    Katherine A. McComas

    2006-01-01

    Ten years ago, scholars suggested that risk communication was embarking on a new phase that would give increased attention to the social contexts that surround and encroach on public responses to risk information. A decade later, many researchers have answered the call, with several defining studies examining the social and psychological influences on risk communication. This article reviews risk communication

  10. Steerable L-band antenna for land mobile voice communication terminal

    NASA Astrophysics Data System (ADS)

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

    1991-10-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  12. Key Distribution Protocol for Digital Mobile Communication Systems

    Microsoft Academic Search

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

    1989-01-01

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

  13. Increased Capacity Using CDMA for Mobile Satellite Communication

    Microsoft Academic Search

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

    1990-01-01

    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

  14. Joint multipath-Doppler diversity in mobile wireless communications

    Microsoft Academic Search

    Akbar M. Sayeed; Behnaam Aazhang

    1999-01-01

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

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

    Microsoft Academic Search

    Paul Haynes

    2010-01-01

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

  16. ValueBased Communication Preservation for Mobile Robots

    E-print Network

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

  17. Value-Based Communication Preservation for Mobile Robots

    E-print Network

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

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

    ERIC Educational Resources Information Center

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

    2014-01-01

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

  19. 48 CFR 6.302-3 - Industrial mobilization; engineering, developmental, or research capability; or expert services.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... false Industrial mobilization; engineering, developmental, or research capability...302-3 Industrial mobilization; engineering, developmental, or research capability...To establish or maintain an essential engineering, research, or development...

  20. 48 CFR 6.302-3 - Industrial mobilization; engineering, developmental, or research capability; or expert services.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... false Industrial mobilization; engineering, developmental, or research capability...302-3 Industrial mobilization; engineering, developmental, or research capability...To establish or maintain an essential engineering, research, or development...

  1. 48 CFR 6.302-3 - Industrial mobilization; engineering, developmental, or research capability; or expert services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... false Industrial mobilization; engineering, developmental, or research capability...302-3 Industrial mobilization; engineering, developmental, or research capability...To establish or maintain an essential engineering, research, or development...

  2. 48 CFR 6.302-3 - Industrial mobilization; engineering, developmental, or research capability; or expert services.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... false Industrial mobilization; engineering, developmental, or research capability...302-3 Industrial mobilization; engineering, developmental, or research capability...To establish or maintain an essential engineering, research, or development...

  3. 48 CFR 6.302-3 - Industrial mobilization; engineering, developmental, or research capability; or expert services.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... false Industrial mobilization; engineering, developmental, or research capability...302-3 Industrial mobilization; engineering, developmental, or research capability...To establish or maintain an essential engineering, research, or development...

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

    E-print Network

    Suzuki, Masatsugu

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

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

    PubMed

    Meder, Allison M; Wegner, Jane R

    2015-03-01

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

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

    SciTech Connect

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

    2009-01-01

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

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

    E-print Network

    Madiraju, Praveen

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

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

    E-print Network

    Murray, Richard M.

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

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

    E-print Network

    Melbourne, University of

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

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

    NASA Technical Reports Server (NTRS)

    Horstein, M.

    1983-01-01

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

  11. RESOLUTION: Reconfigurable Systems for Mobile Local Communication and Positioning

    Microsoft Academic Search

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

    2007-01-01

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

  12. An adaptive array antenna for mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Milne, Robert

    1990-01-01

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

  13. Intercepting mobile communications: the insecurity of 802.11

    Microsoft Academic Search

    Nikita Borisov; Ian Goldberg; David Wagner

    2001-01-01

    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

  14. A New Mobile Text Telephony System Based on GPRS Communications

    Microsoft Academic Search

    Santiago Aguilera; Sergio Jiménez; Daniel Bolaños; Mari-satur Torre; José Colás

    2004-01-01

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

  15. Pseudo-analog speech transmission in mobile radio communication systems

    Microsoft Academic Search

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

    1993-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Dixon, Cory

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

  17. Go Math! How Research Anchors New Mobile Learning Environments

    Microsoft Academic Search

    A. Alexander; K. P. Blair; S. Goldman; O. Jimenez; M. Nakaue; R. Pea; A. Russell

    2010-01-01

    A reciprocal research and design process (RR & D) became central to the development of mobile learning environments for families. Go Math! applications were developed to support families in the situations they face in their daily activities where problem solving involves mathematics. The RR & D process is effective for synthesizing design and development choices with consideration of the results

  18. Research and Technology in Wave Energy for Electric Mobility

    E-print Network

    Frandsen, Jannette B.

    efficiency from the wave or tidal power was low. In recent years, developing marine energy converter systemsResearch and Technology in Wave Energy for Electric Mobility Reza Ghorbani Assistant Professor. This was due to both technological and economical challenges in the past. Technically, converting and utilizing

  19. Augmented Learning: Research and Design of Mobile Educational Games

    ERIC Educational Resources Information Center

    Klopfer, Eric

    2008-01-01

    New technology has brought with it new tools for learning, and research has shown that the educational potential of video games resonates with scholars, teachers, and students alike. In "Augmented Learning", Eric Klopfer describes the largely untapped potential of mobile learning games--games played on such handheld devices as cell phones, Game…

  20. RESEARCH PAPER Responses of leaf nitrogen and mobile carbohydrates in

    E-print Network

    RESEARCH PAPER Responses of leaf nitrogen and mobile carbohydrates in different Quercus species; environmental changes; global warming; non-structural carbohydrates; oak; soluble sugars; starch. Correspondence. For example, drought was found to influence the rnetabolism of soluble carbohydrates (Hanson & Hitz 1982

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

    NASA Astrophysics Data System (ADS)

    Muthukumar, M.

    2014-08-01

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

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

    PubMed Central

    Muthukumar, M.

    2014-01-01

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

  3. 14.33 Economics Research and Communication, Spring 2002

    E-print Network

    Ellison, Sara Fisher

    Designed to expose students to the process of conducting independent research in empirical economics and effectively communicating the results of the research. Begins with an econometric analysis of an assigned economic ...

  4. Communication Research: New Challenges of the Latin American School.

    ERIC Educational Resources Information Center

    Marques de Melo, Jose

    1993-01-01

    Offers a review of Latin American scholarly research on communication processes from the 1940s to the early 1990s. Notes international interest in this research and the new challenges faced by it. (SR)

  5. Future Directions for Mobile-Agent Research David Kotz, Robert Gray, and Daniela Rus

    E-print Network

    Future Directions for Mobile-Agent Research David Kotz, Robert Gray, and Daniela Rus Based of research on mobile agents and mo- bile code. (A mobile agent is a running program that can move from host, rather than to continue its narrow focus on mobile agents. Furthermore, we encourage the develop- ment

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

    E-print Network

    Meder, Allison

    2012-05-31

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

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

    E-print Network

    Wolisz, Adam

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

  8. Research Statement My research interests lie in the broad areas of mobile health and safety, wireless

    E-print Network

    Cheng, Xiuzhen "Susan"

    and safety, wireless networking, wireless and mobile security, and algorithm design and analysis. My research) waveform design and diversity for UWA-SNs with active sonars are still in its infancy; 3) the transmit and mobile wireless networks to effectively identify the clones that possess the security information

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

    NASA Technical Reports Server (NTRS)

    Yan, Tsun-Yee; Clare, Loren P.

    1986-01-01

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

  10. Shared Communications: Volume 2. In-Depth Systems Research

    SciTech Connect

    Truett, LF

    2004-09-22

    This report is the second of two documents that examine the literature for actual examples of organizations and agencies that share communications resources. While the primary emphasis is on rural, intelligent transportation system (ITS) communications involving transit, examples will not be limited to rural activities, nor to ITS implementation, nor even to transit. In addition, the term ''communication'' will be broadly applied to include all information resources. The first document of this series, ''Shared Communications: Volume I. A Summary and Literature Review'', defines the meaning of the term ''shared communication resources'' and provides many examples of agencies that share resources. This document, ''Shared Communications: Volume II. In-Depth Systems Research'', reviews attributes that contributed to successful applications of the sharing communication resources concept. A few examples of each type of communication sharing are provided. Based on the issues and best practice realworld examples, recommendations for potential usage and recommended approaches for field operational tests are provided.

  11. Future mobile satellite communication concepts at 20/30 GHz

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Hu, Hui; Jiang, Hong

    2007-12-01

    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.

  13. Mobile Learning: The Significance of New Mobile and Wireless Communications Technologies for Education

    Microsoft Academic Search

    Gerard Goggin

    \\u000a At present, the popular perception of mobile telephones in the UK, including the education sector, is generally negative:\\u000a they are perceived as a nuisance and distraction (Stone, 2002, p. 262).\\u000a \\u000a \\u000a The image of schoolchildren staring out of the classroom window, minds preoccupied with daydreams, could be supplanted by\\u000a one of students staring forward — not daydreaming but interacting with vibrating

  14. Providing lightweight telepresence in mobile communication to enhance collaborative living

    E-print Network

    Marmasse, Natalia, 1962-

    2004-01-01

    Two decades of computer-supported cooperative work (CSCW) research has addressed how people work in groups and the role technology plays in the workplace. This body of work has resulted in a myriad of deployed technologies ...

  15. Selection and calculation of overall parameters of laser communicator applied for vehicle mobile target

    NASA Astrophysics Data System (ADS)

    Zhang, Hongtao; Yin, FuChang; Shi, Jiangtian

    2002-09-01

    The model of laser communication system using in vehicle mobile target was built. Optimal design and calculation was analyzed for system performance, such as laser transmission, photoelectric reception and speech information processing and image stabilization. Algorithm of MELP (Mixed Excitation Line Predication) compressed speech scrambling was received in processing voice message, which reached 2.4 kbps digital speech code stream, and realized digitization of laser communication. It was also analyzed carefully about the principle theory of MELP algorithm encoding and decoding as well as algorithm realization used in DSP. Image stabilization and tracking were realized by process signal errors which acquired at quadrant error sensors.

  16. 48 CFR 206.302-3 - Industrial mobilization; or engineering, development, or research capability.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Industrial mobilization; or engineering, development, or research capability. 206.302-3...Competition 206.302-3 Industrial mobilization; or engineering, development, or research...

  17. 48 CFR 206.302-3 - Industrial mobilization, engineering, developmental, or research capability, or expert services.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Industrial mobilization, engineering, developmental, or research capability, or expert services...Open Competition 206.302-3 Industrial mobilization, engineering, developmental, or research capability, or expert...

  18. 48 CFR 206.302-3 - Industrial mobilization; or engineering, development, or research capability.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Industrial mobilization; or engineering, development, or research capability. 206.302-3...Competition 206.302-3 Industrial mobilization; or engineering, development, or research...

  19. 48 CFR 206.302-3 - Industrial mobilization; or engineering, development, or research capability.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Industrial mobilization; or engineering, development, or research capability. 206.302-3...Competition 206.302-3 Industrial mobilization; or engineering, development, or research...

  20. 48 CFR 206.302-3 - Industrial mobilization, engineering, developmental, or research capability, or expert services.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Industrial mobilization, engineering, developmental, or research capability, or expert services...Open Competition 206.302-3 Industrial mobilization, engineering, developmental, or research capability, or expert...

  1. Int. J Mobile Communications, Vol. 3, No. 3, 2005 303 Key issues for the design and development of mobile

    E-print Network

    Pitsillides, Andreas

    : This paper suggests a new approach for developing m-commerce services and applications based on a scheme computing. The efficacy of the proposed approach in a real scenario is discussed. Keywords: m-commerce of the University of Cyprus. His main research interests include communication networks and security, optimisations

  2. DCCPS: HCIRB: CECCR: Centers of Excellence in Cancer Communication Research at The Cancer Research Network Cancer Communication Research Center

    Cancer.gov

    Along with administrative core funding, four research projects were awarded as part of the center’s establishment. In addition, a Discovery Core was funded with the goal of identifying, documenting, and assessing clinical innovations in cancer communication. This Discovery Core was then paired with a Dissemination Core to accelerate the spread of effective practices, programs, and organizational policies into health care systems.

  3. Federal Research and Development for Satellite Communications.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Assembly of Engineering.

    This report of the Committee on Satellite Communications (COSC) reviews a number of future communication needs which could be satisfied by satellite systems, including needs in fields such as education, health care delivery, hazard warning, navigation aids, search and rescue, electronic mail delivery, time and frequency dissemination, and…

  4. Nonverbal Communication: A Research Guide & Bibliography.

    ERIC Educational Resources Information Center

    Key, Mary Ritchie

    This volume discusses various aspects of nonverbal communication and provides an extensive bibliography of journal articles, listed by author, that are relevant to the topic. Commentary is divided into six sections: "Considerations in Nonverbal Communication," which examines the impact of motion and rhythm, the components of nonverbal…

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

    NASA Astrophysics Data System (ADS)

    Salmasi, A. B.

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

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

    NASA Technical Reports Server (NTRS)

    1989-01-01

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

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

    Microsoft Academic Search

    Filippo Giannetti; Marco Luise; Ruggero Reggiannini

    1999-01-01

    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

  8. The future generations of mobile communications based on broadband access technologies

    Microsoft Academic Search

    Shingo Ohmori; Yasushi Yamao; Nobuo Nakajima

    2000-01-01

    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

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

    Microsoft Academic Search

    Fumiyuki Adachi; Mamoru Sawahashi; Hirohito Suda

    1998-01-01

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

  10. A ring model for local\\/mobile radio communications with variable packet length

    Microsoft Academic Search

    Dennis V. Banh

    1990-01-01

    This thesis presents an analysis of the performance of a local\\/mobile radio communications system utilizing the Aloha random access protocol with variable length packets. The capture phenomenon due to the near\\/far effect that enhances the performance of the system is investigated. A tagged packet will capture the base station if its signal-to-interference ratio exceeds a threshold gamma sub zero. Because

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

    Microsoft Academic Search

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

    2005-01-01

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

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

    Microsoft Academic Search

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

    2005-01-01

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

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

    Microsoft Academic Search

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

    1990-01-01

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

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

    Microsoft Academic Search

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

    1988-01-01

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

  15. Real-time communications over wired\\/wireless PROFIBUS networks supporting inter-cell mobility

    Microsoft Academic Search

    Mário Alves; Eduardo Tovar

    2007-01-01

    PROFIBUS is an international standard (IEC 61158, EN 50170) for factory-floor communications, with several thousands of installations worldwide. Taking into account the increasing need for mobile devices in industrial environments, one obvious solution is to extend traditional wired PROFIBUS networks with wireless capabilities. In this paper, we outline the major aspects of a hybrid wired\\/wireless PROFIBUS-based architecture, where most of

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

    PubMed Central

    Schooley, Benjamin; San Nicolas-Rocca, Tonia

    2015-01-01

    Background Many studies have provided evidence of the importance of quality provider-patient communications and have suggested improvements to patient understanding by using video-based instruction. Objective The objective of this study was to understand how mobile information technology assisted video and three-dimensional (3D) image instruction, provided by a health care worker, influences two categories of outcome: (1) patient understanding of information about their condition and detailed medical discharge instructions; and (2) patient perceptions and attitudes toward their health care providers, which included physicians, nurses, and staff. We hypothesize that video and 3D image instruction, provided on a mobile, tablet hardware platform, will improve patient understanding about the diagnostic testing, diagnoses, procedures, medications, and health topics provided to them. We also propose that use of the tablet/video combination will result in improved attitudinal evaluation by patients of their providers and the treatment plan. Methods This study evaluated a hospital clinic-based trial (patient N=284) of video and 3D image instruction, provided on a mobile, tablet hardware platform, and its potential to improve patient understanding about the diagnostic testing, diagnoses, procedures, medications, and health topics provided to them. Results Results showed strong evidence that the system was perceived as helpful for improving patient understanding, and that it improved communication between physicians and patients (P<.001). The advanced age of some patients had no effect on their perceptions of the tablet-based mediation. Physician comments provided useful insights on effective use of such systems in the future. Implications for further development and future research are discussed. Conclusions This study added to the body of evidence that computer-assisted video instructional systems for patients can improve patient understanding of medical instructions from their health care providers and assist with patient compliance. In addition, such systems can be appealing to both patient and provider. PMID:25583145

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

    NASA Technical Reports Server (NTRS)

    Ames, William G.

    1990-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    Hayes, Edward J.; Keelty, J. Malcolm

    1991-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Hayes, Edward J.; Keelty, J. Malcolm

    1991-09-01

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