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Sample records for aeronautical mobile communications

  1. 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).

  2. 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.

  3. 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.

  4. Interference Analysis for an Aeronautical Mobile Airport Communications System

    NASA Technical Reports Server (NTRS)

    Wilson, Jeffrey D.; Kercewski, Robert J.

    2010-01-01

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

  5. 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.

  6. 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

  7. OSI applied to aeronautical satellite mobile communications in EURATN

    NASA Astrophysics Data System (ADS)

    Monteil, Franck

    1992-07-01

    The future Aeronautical Telecommunication Network ATN being standardized by ICAO (International Civil Aviation Organization) and application of OSI (Open Systems Interconnection) are described. The concepts developed by paper work have reached such a maturity that a validation step is now essential in parallel with futher ATN specification activity. This validation requires the development of an experimental ATN. This is the aim of the EURATN project. The Satcom satellite subnetwork will be part of this experimental ATN. The EURATN project will provide an experimental ATN, both for the validation aspects mentioned above and for ATM (Air Traffic Management) enhancement trials. Such experimental activities will be performed after EURATN completion, possibly in the frame of a EURATN 2 project.

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

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Wilson, Jeffrey D.

    2010-01-01

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

  9. Mobile-ip Aeronautical Network Simulation Study

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.; Tran, Diepchi T.

    2001-01-01

    NASA is interested in applying mobile Internet protocol (mobile-ip) technologies to its space and aeronautics programs. In particular, mobile-ip will play a major role in the Advanced Aeronautic Transportation Technology (AATT), the Weather Information Communication (WINCOMM), and the Small Aircraft Transportation System (SATS) aeronautics programs. This report presents the results of a simulation study of mobile-ip for an aeronautical network. The study was performed to determine the performance of the transmission control protocol (TCP) in a mobile-ip environment and to gain an understanding of how long delays, handoffs, and noisy channels affect mobile-ip performance.

  10. Canadian aeronautical mobile data trials

    NASA Technical Reports Server (NTRS)

    Pedersen, Allister; Pearson, Andrea

    1993-01-01

    This paper describes a series of aeronautical mobile data trials conducted on small aircraft (helicopters and fixed wing) utilizing a low-speed store-and-forward mobile data service. The paper outlines the user requirements for aeronautical mobile satellite communications. 'Flight following' and improved wide-area dispatch communications were identified as high priority requirements. A 'proof-of-concept' trial in a Cessna Skymaster aircraft is described. This trial identified certain development work as essential to the introduction of commercial service including antenna development, power supply modifications and doppler software modifications. Other improvements were also proposed. The initial aeronautical mobile data service available for pre-operational (Beta) trials is outlined. Pre-operational field trials commenced in October 1992 and consisted of installations on a Gralen Communications Inc. Cessna 177 and an Aerospatiale Astar 350 series light single engine helicopter. The paper concludes with a discussion of desirable near term mobile data service developments, commercial benefits, current safety benefits and potential future applications for improved safety.

  11. Inmarsat aeronautical mobile satellite system: Internetworking issues

    NASA Technical Reports Server (NTRS)

    Sengupta, Jay R.

    1990-01-01

    The Inmarsat Aeronautical Mobile Satellite System (AMSS) provides air-ground and air-air communications services to aero-mobile users on a global basis. Communicating parties may be connected either directly, or more commonly, via interconnecting networks to the Inmarsat AMSS, in order to construct end-to-end communications circuits. The aircraft earth station (AES) and the aeronautical ground earth station (GES) are the points of interconnection of the Inmarsat AMSS to users, as well as to interconnecting networks. This paper reviews the internetworking aspects of the Inmarsat AMSS, by introducing the Inmarsat AMSS network architecture and services concepts and then discussing the internetwork address/numbering and routing techniques.

  12. Application of Mobile-ip to Space and Aeronautical Networks

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

    The National Aeronautics and Space Administration (NASA) is interested in applying mobile Internet protocol (mobile-ip) technologies to its space and aeronautics programs. In particular, mobile-ip will play a major role in the Advanced Aeronautic Transportation Technology (AAT-F), the Weather Information Communication (WINCOMM), and the Small Aircraft Transportation System (SATS) aeronautics programs. This paper describes mobile-ip and mobile routers--in particular, the features, capabilities, and initial performance of the mobile router are presented. The application of mobile-router technology to NASA's space and aeronautics programs is also discussed.

  13. An aeronautical mobile satellite experiment

    NASA Technical Reports Server (NTRS)

    Jedrey, T. C.; Dessouky, K. I.; Lay, N. E.

    1990-01-01

    The various activities and findings of a NASA/FAA/COMSAT/INMARSAT collaborative aeronautical mobile satellite experiment are detailed. The primary objective of the experiment was to demonstrate and evaluate an advanced digital mobile satellite terminal developed at the Jet Propulsion Laboratory under the NASA Mobile Satellite Program. The experiment was a significant milestone for NASA/JPL, since it was the first test of the mobile terminal in a true mobile satellite environment. The results were also of interest to the general mobile satellite community because of the advanced nature of the technologies employed in the terminal.

  14. Aeronautical Mobile Satellite Service (AMSS) test plan

    NASA Astrophysics Data System (ADS)

    Sandlin, Sean M.

    1991-05-01

    A test program is described which will be conducted by the Federal Aviation Administration to support the validation of Standards and Recommended Practices being developed for the Aeronautical Mobile Satellite Service by the International Civil Aviation Organization. A description of the Communication Test Facility is also presented which will be used to perform the tests. A brief description is also included of each test to be performed along with setup and data to be recorded.

  15. Aeronautical mobile satellite service: An overview

    NASA Astrophysics Data System (ADS)

    Rigley, Jack

    Successful flight trials of Aeronautical Mobile Satellite Services (AMSS) were first carried out in the 1960's but it is only in the past few years that plans to implement such a system have achieved any degree of certainty. System architecture has been agreed upon by users, service providers, and manufacturers. Detailed avionic characteristics have been approved and the International Civil Aviation Organization is currently preparing AMSS standards which will ensure the safety and regularity of international air traffic. In this paper, a review is provided of the history of AMSS, especially of Canadian participation, and a description of the technical and operational features of the system are given. The system will use the 1545-1555 and 1646.5-1656.5 MHz bands for satellite to aircraft and aircraft to satellite communication. Different categories of communication including air traffic control, aeronautical operational control, aeronautical administrative communications, and aeronautical passenger communication, will be assigned different priorities. A set of radio frequency (RF) channels have been defined to accommodate all foreseen traffic types. Standards for the avionics required for large passenger planes have been developed by the Airlines Electronic Engineering Committee.

  16. Future Aeronautical Communication Infrastructure Technology Investigation

    NASA Technical Reports Server (NTRS)

    Gilbert, Tricia; Jin, Jenny; Bergerm Jason; Henriksen, Steven

    2008-01-01

    This National Aeronautics and Space Administration (NASA) Contractor Report summarizes and documents the work performed to investigate technologies that could support long-term aeronautical mobile communications operating concepts for air traffic management (ATM) in the timeframe of 2020 and beyond, and includes the associated findings and recommendations made by ITT Corporation and NASA Glenn Research Center to the Federal Aviation Administration (FAA). The work was completed as the final phase of a multiyear NASA contract in support of the Future Communication Study (FCS), a cooperative research and development program of the United States FAA, NASA, and EUROCONTROL. This final report focuses on an assessment of final five candidate technologies, and also provides an overview of the entire technology assessment process, including final recommendations.

  17. Mobile SATCOM Antenna Developments and Experimental Results of Land- and Aeronautical -Mobile Field Trials

    NASA Technical Reports Server (NTRS)

    Densmore, A. C.; Huang, J.

    1996-01-01

    This paper discusses several mobile satcom antenna systems that the Jet Propulsion Laboratory (JPL) has developed and demonstrated during the last ten years for land -and aeronautical mobile digital audio/data/video satellite communication.

  18. A CCIR aeronautical mobile satellite report

    NASA Technical Reports Server (NTRS)

    Davarian, Faramaz; Bishop, Dennis; Rogers, David; Smith, Ernest K.

    1989-01-01

    Propagation effects in the aeronautical mobile-satellite service differ from those in the fixed-satellite service and other mobile-satellite services because: small antennas are used on aircraft, and the aircraft body may affect the performance of the antenna; high aircraft speeds cause large Doppler spreads; aircraft terminals must accommodate a large dynamic range in transmission and reception; and due to their high speeds, banking maneuvers, and three-dimensional operation, aircraft routinely require exceptionally high integrity of communications, making even short-term propagation effects very important. Data and models specifically required to characterize the path impairments are discussed, which include: tropospheric effects, including gaseous attenuation, cloud and rain attenuation, fog attenuation, refraction and scintillation; surface reflection (multipath) effects; ionospheric effects such as scintillation; and environmental effects (aircraft motion, sea state, land surface type). Aeronautical mobile-satellite systems may operate on a worldwide basis, including propagation paths at low elevation angles. Several measurements of multipath parameters over land and sea were conducted. In some cases, laboratory simulations are used to compare measured data and verify model parameters. The received signals is considered in terms of its possible components: a direct wave subject to atmospheric effects, and a reflected wave, which generally contains mostly a diffuse component.

  19. A geostationary satellite system for mobile multimedia applications using portable, aeronautical and mobile terminals

    NASA Technical Reports Server (NTRS)

    Losquadro, G.; Luglio, M.; Vatalaro, F.

    1997-01-01

    A geostationary satellite system for mobile multimedia services via portable, aeronautical and mobile terminals was developed within the framework of the Advanced Communications Technology Service (ACTS) programs. The architecture of the system developed under the 'satellite extremely high frequency communications for multimedia mobile services (SECOMS)/ACTS broadband aeronautical terminal experiment' (ABATE) project is presented. The system will be composed of a Ka band system component, and an extremely high frequency band component. The major characteristics of the space segment, the ground control station and the portable, aeronautical and mobile user terminals are outlined.

  20. Multibeam satellite EIRP adaptability for aeronautical communications.

    NASA Technical Reports Server (NTRS)

    Kinal, G. V.; Bisaga, J. J.

    1973-01-01

    EIRP enhancement and management techniques, emphasizing aeronautical communications and adaptable multibeam concepts, are classified and characterized. User requirement and demand characteristics that exploit the improvement available from each technique are identified, and the relative performance improvement of each is discussed. It is concluded that aeronautical satellite communications could benefit greatly by the employment of these techniques.

  1. An aeronautical-mobile satellite experiment

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    The various activities and findings of a NASA/FAA/COMSAT/INMARSAT collaborative aeronautical mobile-satellite experiment are detailed. The primary objective of the experiment was to demonstrate and evaluate an advanced digital mobile-satellite terminal developed at the Jet Propulsion Laboratory under the NASA Mobile Satellite Program. The experiment was a significant milestone for NASA/JPL, since it was the first test of the mobile terminal in a true mobile-satellite environment. The results were also of interest to the general mobile-satellite community because of the advanced nature of the technologies employed in the terminal.

  2. World-wide aeronautical satellite communications

    NASA Technical Reports Server (NTRS)

    Wood, Peter; Smith, Keith

    1988-01-01

    INMARSAT decided to expand the spectrum covered by its new generation of satellites, INMARSAT-2, to include 1 MHz (subsequently increased to 3 MHz) of the spectrum designed for aeronautical use. It began a design study that led to the specifications for the system that is now being implemented. Subsequently, INMARSAT awarded contracts for the design of avionics and high gain antennas to a number of manufactures, while several of the signatories that provide ground equipment for communicating with the INMARSAT satellites are modifying their earth stations to work with the avionic equipment. As a resullt of these activities, a world-wide aeronautical satellite system supporting both voice and data will become operational in 1989.

  3. Future developments in aeronautical satellite communications

    NASA Technical Reports Server (NTRS)

    Wood, Peter

    1990-01-01

    Very shortly aeronautical satellite communications will be introduced on a world wide basis. By the end of the year, voice communications (both to the cabin and cockpit) and packet data communications will be available to both airlines and executive aircraft. During the decade following the introduction of the system, there will be many enhancements and developments which will increase the range of applications, expand the potential number of users, and reduce costs. A number of ways in which the system is expected to evolve over this period are presented. Among the issues which are covered are the impact of spot beam satellites, spectrum and power conservation techniques, and the expanding range of user services.

  4. Technology Assessment for the Future Aeronautical Communications System

    NASA Technical Reports Server (NTRS)

    Budinger, James M. (Technical Monitor)

    2005-01-01

    To address emerging saturation in the VHF aeronautical bands allocated internationally for air traffic management communications, the International Civil Aviation Organization (ICAO) has requested development of a common global solution through its Aeronautical Communications Panel (ACP). In response, the Federal Aviation Administration (FAA) and Eurocontrol initiated a joint study, with the support of NASA and U.S. and European contractors, to provide major findings on alternatives and recommendations to the ICAO ACP Working Group C (WG-C). Under an FAA/Eurocontrol cooperative research and development agreement, ACP WG-C Action Plan 17 (AP-17), commonly referred to as the Future Communications Study (FCS), NASA Glenn Research Center is responsible for the investigation of potential communications technologies that support the long-term mobile communication operational concepts of the FCS. This report documents the results of the first phase of the technology assessment and recommendations referred to in the Technology Pre-Screening Task 3.1 of AP-17. The prescreening identifies potential technologies that are under development in the industry and provides an initial assessment against a harmonized set of evaluation criteria that address high level capabilities, projected maturity for the time frame for usage in aviation, and potential applicability to aviation. A wide variety of candidate technologies were evaluated from several communications service categories including: cellular telephony; IEEE-802.xx standards; public safety radio; satellite and over-the-horizon communications; custom narrowband VHF; custom wideband; and military communications.

  5. Satellite Communications for Aeronautics Applications: Technology Development and Demonstration

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Hoder, Douglas J.; Zakrajsek, Robert J.

    2001-01-01

    The National Aeronautics and Space Administration (NASA) is performing research and development to improve the safety and increase the capacity of the National Airspace System (NAS). Improved communications, especially to and from the aircraft flight deck, has been identified as an essential enabling technology for future improvements to the air traffic management system and aviation safety. NASA's Glenn Research Center is engaged in research and development of satellite communications technologies for aeronautical applications. A mobile aero terminal has been developed for use with Ku band commercial communications satellites. This experimental terminal will be used in mobile ground and air-based tests and demonstrations during 2000-2004. This paper will describe the basic operational parameters of the Ku Band aero terminal, the communications architecture it is intended to demonstrate, and the key technology issues being addressed in the tests and demonstrations. The design of the Ku Band aero terminal and associated ground testbed, planned tests and demonstrations, and results to date will be presented.

  6. A Hybrid Satellite-Terrestrial Approach to Aeronautical Communication Networks

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Chomos, Gerald J.; Griner, James H.; Mainger, Steven W.; Martzaklis, Konstantinos S.; Kachmar, Brian A.

    2000-01-01

    Rapid growth in air travel has been projected to continue for the foreseeable future. To maintain a safe and efficient national and global aviation system, significant advances in communications systems supporting aviation are required. Satellites will increasingly play a critical role in the aeronautical communications network. At the same time, current ground-based communications links, primarily very high frequency (VHF), will continue to be employed due to cost advantages and legacy issues. Hence a hybrid satellite-terrestrial network, or group of networks, will emerge. The increased complexity of future aeronautical communications networks dictates that system-level modeling be employed to obtain an optimal system fulfilling a majority of user needs. The NASA Glenn Research Center is investigating the current and potential future state of aeronautical communications, and is developing a simulation and modeling program to research future communications architectures for national and global aeronautical needs. This paper describes the primary requirements, the current infrastructure, and emerging trends of aeronautical communications, including a growing role for satellite communications. The need for a hybrid communications system architecture approach including both satellite and ground-based communications links is explained. Future aeronautical communication network topologies and key issues in simulation and modeling of future aeronautical communications systems are described.

  7. Additional Technologies and Investigations for Provision of Future Aeronautical Communications

    NASA Technical Reports Server (NTRS)

    Gilbert, Tricia; Jin, Jenny; Berger, Jason; Henriksen, Steve

    2008-01-01

    The following NASA Contractor Report documents the in-depth studies on select technologies that could support long-term aeronautical mobile communications operating concepts. This work was performed during the third and final phase of NASA s Technology Assessment for the Federal Aviation Administration (FAA)/EUROCONTROL Future Communications Study (FCS) under a multiyear NASA contract. It includes the associated findings of ITT Corporation and NASA Glenn Research Center to the FAA as of the end of May 2007. The activities documented in this report focus on three final technology candidates identified by the United States, and were completed before sufficient information about two additional technology candidates proposed by EUROCONTROL was made available. A separate report to be published by NASA/CR-2008-215144, entitled Final Report on Technology Investigations for Provision of Future Aeronautical Communications will include an assessment of all five final candidate technologies considered by the U.S. agencies (FAA and NASA) and EUROCONTROL. It will also provide an overview of the entire technology assessment process, including final recommendations. All three phases of this work were performed in compliance with the Terms of Reference for the Action Plan number 17 (AP-17) cooperative research agreement among EUROCONTROL, FAA, and NASA along with the general guidance of the FAA and EUROCONTROL available throughout this study.

  8. Aeronautical Mobile Satellite Service (AMSS) Test Plan

    DTIC Science & Technology

    1991-05-01

    ICAO ) . It also contains a description of the Communications Test Facility (CTF) which will be used to perform the tests. An appendix includes a brief description of each test to be performed along with setup and data to be recorded.

  9. Application of the Iridium Satellite System to Aeronautical Communications

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Meza, Mike; Gupta, Om

    2008-01-01

    The next generation air transportation system will require greater air-ground communications capacity to accommodate more air traffic with increased safety and efficiency. Communications will remain primarily terrestrially based, but satellite communications will have an increased role. Inmarsat s aeronautical services have been approved and are in use for aeronautical safety communications provided by geostationary satellites. More recently the approval process for the Iridium low earth orbit constellation is nearing completion. The current Iridium system will be able to provide basic air traffic services communications suitable for oceanic, remote and polar regions. The planned second generation of the Iridium system, called Iridium NEXT, will provide enhanced capabilities and enable a greater role in the future of aeronautical communications. This paper will review the potential role of satellite communications in the future of air transportation, the Iridium approval process and relevant system testing, and the potential role of Iridium NEXT.

  10. Digital, Satellite-Based Aeronautical Communication

    NASA Technical Reports Server (NTRS)

    Davarian, F.

    1989-01-01

    Satellite system relays communication between aircraft and stations on ground. System offers better coverage with direct communication between air and ground, costs less and makes possible new communication services. Carries both voice and data. Because many data exchanged between aircraft and ground contain safety-related information, probability of bit errors essential.

  11. Identification of Technologies for Provision of Future Aeronautical Communications

    NASA Technical Reports Server (NTRS)

    Gilbert, Tricia; Dyer, Glen; Henriksen, Steve; Berger, Jason; Jin, Jenny; Boci, Tony

    2006-01-01

    This report describes the process, findings, and recommendations of the second of three phases of the Future Communications Study (FCS) technology investigation conducted by NASA Glenn Research Center and ITT Advanced Engineering & Sciences Division for the Federal Aviation Administration (FAA). The FCS is a collaborative research effort between the FAA and Eurocontrol to address frequency congestion and spectrum depletion for safety critical airground communications. The goal of the technology investigation is to identify technologies that can support the longterm aeronautical mobile communication operating concept. A derived set of evaluation criteria traceable to the operating concept document is presented. An adaptation of the analytical hierarchy process is described and recommended for selecting candidates for detailed evaluation. Evaluations of a subset of technologies brought forward from the prescreening process are provided. Five of those are identified as candidates with the highest potential for continental airspace solutions in L-band (P-34, W-CDMA, LDL, B-VHF, and E-TDMA). Additional technologies are identified as best performers in the unique environments of remote/oceanic airspace in the satellite bands (Inmarsat SBB and a custom satellite solution) and the airport flight domain in C-band (802.16e). Details of the evaluation criteria, channel models, and the technology evaluations are provided in appendixes.

  12. Future Aeronautical Communication System (FACS): Report

    NASA Astrophysics Data System (ADS)

    Hof, H. J.

    1985-06-01

    The feasibility of a FACS design, particularly with regard to application possibilities of satellites, was investigated. It was assumed that communication between airborne stations and air traffic control centers is exclusively possible via satellites using mainly voice communication (possibly completed by data communication). It is concluded that integration possibilities of satellites are mainly limited by the airborne antenna chosen. As a solution, phase steered microstrip antenna arrays are presented. However, the use of these antennas is limited to large (long-distance) aircraft. For operational feasibility, it is concluded that communication should take place in the high frequency band.

  13. 77 FR 30046 - Ninth Meeting: RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite (Route) Services

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ... Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite... RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite (Route) Services. DATES: The...

  14. 76 FR 66350 - Eighth Meeting: RTCA Special Committee 222 Inmarsat Aeronautical Mobile Satellite (Route) Services

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-26

    ... Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Notice of RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite (Route... Committee 222, Inmarsat Aeronautical Mobile Satellite (Route) Services for the Eighth Meeting. DATES:...

  15. 77 FR 48584 - Tenth Meeting: RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite (Route) Services

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-14

    ... Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), U.S. Department of Transportation (DOT). ACTION: Meeting Notice of RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite... RTCA Special Committee 222, Inmarsat Aeronautical Mobile Satellite (Route) Services. DATES: The...

  16. 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.

  17. Autonomous mobile communication relays

    NASA Astrophysics Data System (ADS)

    Nguyen, Hoa G.; Everett, Hobart R.; Manouk, Narek; Verma, Ambrish

    2002-07-01

    Maintaining a solid radio communication link between a mobile robot entering a building and an external base station is a well-recognized problem. Modern digital radios, while affording high bandwidth and Internet-protocol-based automatic routing capabilities, tend to operate on line-of-sight links. The communication link degrades quickly as a robot penetrates deeper into the interior of a building. This project investigates the use of mobile autonomous communication relay nodes to extend the effective range of a mobile robot exploring a complex interior environment. Each relay node is a small mobile slave robot equipped with sonar, ladar, and 802.11b radio repeater. For demonstration purposes, four Pioneer 2-DX robots are used as autonomous mobile relays, with SSC-San Diego's ROBART III acting as the lead robot. The relay robots follow the lead robot into a building and are automatically deployed at various locations to maintain a networked communication link back to the remote operator. With their on-board external sensors, they also act as rearguards to secure areas already explored by the lead robot. As the lead robot advances and RF shortcuts are detected, relay nodes that become unnecessary will be reclaimed and reused, all transparent to the operator. This project takes advantage of recent research results from several DARPA-funded tasks at various institutions in the areas of robotic simulation, ad hoc wireless networking, route planning, and navigation. This paper describes the progress of the first six months of the project.

  18. Mobile Aerial Tracking and Imaging System (MATRIS) for Aeronautical Research

    NASA Technical Reports Server (NTRS)

    Banks, Daniel W.; Blanchard, R. C.; Miller, G. M.

    2004-01-01

    A mobile, rapidly deployable ground-based system to track and image targets of aeronautical interest has been developed. Targets include reentering reusable launch vehicles (RLVs) as well as atmospheric and transatmospheric vehicles. The optics were designed to image targets in the visible and infrared wavelengths. To minimize acquisition cost and development time, the system uses commercially available hardware and software where possible. The conception and initial funding of this system originated with a study of ground-based imaging of global aerothermal characteristics of RLV configurations. During that study NASA teamed with the Missile Defense Agency/Innovative Science and Technology Experimentation Facility (MDA/ISTEF) to test techniques and analysis on two Space Shuttle flights.

  19. Emerging Definition of Next-Generation of Aeronautical Communications

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.

    2006-01-01

    Aviation continues to experience rapid growth. In regions such as the United States and Europe air traffic congestion is constraining operations, leading to major new efforts to develop methodologies and infrastructures to enable continued aviation growth through transformational air traffic management systems. Such a transformation requires better communications linking airborne and ground-based elements. Technologies for next-generation communications, the required capacities, frequency spectrum of operation, network interconnectivity, and global interoperability are now receiving increased attention. A number of major planning and development efforts have taken place or are in process now to define the transformed airspace of the future. These activities include government and industry led efforts in the United States and Europe, and by international organizations. This paper will review the features, approaches, and activities of several representative planning and development efforts, and identify the emerging global consensus on requirements of next generation aeronautical communications systems for air traffic control.

  20. Land mobile communications satellite

    NASA Astrophysics Data System (ADS)

    Carnebianca, C.; Pavesi, B.; Tuozzi, A.

    1986-09-01

    The economic value and salient technical and operational characteristics of a European Land Mobile Communication Satellite (LMCS) to complement and supplement the demand for mobile services of Western European countries in the 1995 to 2005 time frames were assessed. A significant future expansion of demand for LCMS services on the part of the public is anticipated. Important augmentations of current service capabilities could be achieved by a satellite service, improving the overall system performances and/or assisting the PTT's in containing their investments in the required infrastructure. The satellite service itself could represent a profitable revenue producer.

  1. 75 FR 39724 - Sixth Meeting-Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-12

    ... Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services meeting. SUMMARY: The FAA... Aeronautical Mobile Satellite (Route) Services. DATES: The meeting will be held Tuesday, August 3, 2010 from...

  2. 75 FR 15770 - Fifth Meeting-Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-30

    ... Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services meeting. SUMMARY: The FAA... Aeronautical Mobile Satellite (Route) Services. DATES: The meeting will be held Tuesday, April 20, 2010 from...

  3. 75 FR 63534 - Seventh Meeting-Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-15

    ... Satellite (Route) Services AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of RTCA Special Committee 222: Inmarsat Aeronautical Mobile Satellite (Route) Services meeting. SUMMARY: The FAA... Aeronautical Mobile Satellite (Route) Services. DATES: The meeting will be held November 3-5, 2010,...

  4. Characteristics of a future aeronautical satellite communications system

    NASA Technical Reports Server (NTRS)

    Sohn, Philip Y.; Stern, Alan; Schmidt, Fred

    1991-01-01

    A possible operational system scenario for providing satellite communications services to the future aviation community was analyzed. The system concept relies on a Ka-band (20/30 GHz) satellite that utilizes multibeam antenna (MBA) technology. The aircraft terminal uses an extremely small aperture antenna as a result of using this higher spectrum at Ka-band. The satellite functions as a relay between the aircraft and the ground stations. The ground stations function as interfaces to the existing terrestrial networks such as the Public Service Telephone Network (PSTN). Various system tradeoffs are first examined to ensure optimized system parameters. High level performance specifications and design approaches are generated for the space, ground, and aeronautical elements in the system. Both technical and economical issues affecting the feasibility of the studied concept are addressed with the 1995 timeframe in mind.

  5. Advanced Communications Technology: Mobile Communications Requirements Report

    NASA Astrophysics Data System (ADS)

    1998-05-01

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

  6. NASA's K/Ka-Band Broadband Aeronautical Terminal for Duplex Satellite Video Communications

    NASA Technical Reports Server (NTRS)

    Densmore, A.; Agan, M.

    1994-01-01

    JPL has recently begun the development of a Broadband Aeronautical Terminal (BAT) for duplex video satellite communications on commercial or business class aircraft. The BAT is designed for use with NASA's K/Ka-band Advanced Communications Technology Satellite (ACTS). The BAT system will provide the systems and technology groundwork for an eventual commercial K/Ka-band aeronautical satellite communication system. With industry/government partnerships, three main goals will be addressed by the BAT task: 1) develop, characterize and demonstrate the performance of an ACTS based high data rate aeronautical communications system; 2) assess the performance of current video compression algorithms in an aeronautical satellite communication link; and 3) characterize the propagation effects of the K/Ka-band channel for aeronautical communications.

  7. The benefits of mobile communications

    NASA Astrophysics Data System (ADS)

    1985-04-01

    The benefits offered by mobile communications facilities are compared to conventionally priced networks. Sweden, the UK and Eire were taken as examples of markets that are respectively leading, growing and restrictive. The three major benefits identified are higher profits for commercial organizations from cost savings and improved productivity, the prevention and minimization of damage to life and property, and better social contacts for people isolated from communities. Case studies provide examples of the benefits different occupational and social groups acquire from mobile communications in each country. The studies were also used to project future growth in the uptake and range of mobile communications facilities offered in each country.

  8. An ocean scatter propagation model for aeronautical satellite communication applications

    NASA Technical Reports Server (NTRS)

    Moreland, K. W.

    1990-01-01

    In this paper an ocean scattering propagation model, developed for aircraft-to-satellite (aeronautical) applications, is described. The purpose of the propagation model is to characterize the behavior of sea reflected multipath as a function of physical propagation path parameters. An accurate validation against the theoretical far field solution for a perfectly conducting sinusoidal surface is provided. Simulation results for typical L band aeronautical applications with low complexity antennas are presented.

  9. Computer simulation and performance assessment of the packet-data service of the Aeronautical Mobile Satellite Service (AMSS)

    NASA Technical Reports Server (NTRS)

    Ferzali, Wassim; Zacharakis, Vassilis; Upadhyay, Triveni; Weed, Dennis; Burke, Gregory

    1995-01-01

    The ICAO Aeronautical Mobile Communications Panel (AMCP) completed the drafting of the Aeronautical Mobile Satellite Service (AMSS) Standards and Recommended Practices (SARP's) and the associated Guidance Material and submitted these documents to ICAO Air Navigation Commission (ANC) for ratification in May 1994. This effort, encompassed an extensive, multi-national SARP's validation. As part of this activity, the US Federal Aviation Administration (FAA) sponsored an effort to validate the SARP's via computer simulation. This paper provides a description of this effort. Specifically, it describes: (1) the approach selected for the creation of a high-fidelity AMSS computer model; (2) the test traffic generation scenarios; and (3) the resultant AMSS performance assessment. More recently, the AMSS computer model was also used to provide AMSS performance statistics in support of the RTCA standardization activities. This paper describes this effort as well.

  10. Globalstar communications payload for global mobile communications

    NASA Astrophysics Data System (ADS)

    Louie, Ming; Monte, Paul; Tyner, Randy; Rouffet, Denis; Gilhousen, Klein S.

    1992-03-01

    The Globalstar LEO satellite-based mobile-communications system is evaluated with respect to its potential for global digital communications and for radio-determination satellite service. The significant novel attributes of the Globalsat payload are examined including code-division multiple-access technologies, beam-hopping and time-domain-duplexing (TDD) capabilities, and six elliptical spot-beam L/S-band antennas. The antennas are designed to address the 'near-far' problem associated with mobile systems through the use of the Isoflux design. The Isoflux beams provide gain contours that compensate for differences in the spacecraft/earth slant range and that provide low spillover illumination. Two candidate payloads are presented - one which incorporates TDD and beam hopping - and found to provide efficient global mobile-communications services for the Globalstar system. A single satellite can provide up to 2800 full-duplex voice channels, and TDD allows uplink and downlink signals to share the same frequency.

  11. Development of standards for aeronautical satellite navigation system [rapid communication

    NASA Astrophysics Data System (ADS)

    Iatsouk, Victor

    2004-06-01

    One of the work objectives of the International Civil Aviation Organisation (ICAO) is the development of the standards and procedures necessary to support transition to the CNS/ATM systems, which include Global Navigation Satellite System (GNSS). The Global Navigation Satellite System Panel (GNSSP) was established by the ICAO Air Navigation Commission in 1993 with the basic objective to develop ICAO standards and recommended practices (SARPs) and guidance material as required to support aeronautical GNSS applications world-wide. The first package of GNSS SARPs was adopted and published by ICAO in 2001, and further work is under way to introduce new satellite constellations and system elements in an evolutionary fashion.

  12. Packet-Based Protocol Efficiency for Aeronautical and Satellite Communications

    NASA Technical Reports Server (NTRS)

    Carek, David A.

    2005-01-01

    This paper examines the relation between bit error ratios and the effective link efficiency when transporting data with a packet-based protocol. Relations are developed to quantify the impact of a protocol s packet size and header size relative to the bit error ratio of the underlying link. These relations are examined in the context of radio transmissions that exhibit variable error conditions, such as those used in satellite, aeronautical, and other wireless networks. A comparison of two packet sizing methodologies is presented. From these relations, the true ability of a link to deliver user data, or information, is determined. Relations are developed to calculate the optimal protocol packet size forgiven link error characteristics. These relations could be useful in future research for developing an adaptive protocol layer. They can also be used for sizing protocols in the design of static links, where bit error ratios have small variability.

  13. Technical Communications in Aeronautics: Results of an Exploratory Study. NASA Technical Memorandum 101534, Parts 1 and 2.

    ERIC Educational Resources Information Center

    Pinelli, Thomas E.; And Others

    An exploratory study investigated technical communications in aeronautics by surveying aeronautical engineers and scientists. The study had five specific objectives: to solicit the opinions of aeronautical engineers and scientists regarding the importance of technical communications to their profession; to determine their use and production of…

  14. National Aeronautics and Space Administration plans for space communication technology

    NASA Technical Reports Server (NTRS)

    Alexovich, R. E.

    1979-01-01

    A program plan is presented for a space communications application utilizing the 30/20 GHz frequency bands (30 GHz uplink and 20 GHz downlink). Results of market demand studies and spacecraft systems studies which significantly affect the supporting research and technology program are also presented, along with the scheduled activities of the program plan.

  15. NPA's land mobile satellite communication experiments using ETS-V

    NASA Astrophysics Data System (ADS)

    Sekine, H.; Miyata, Y.; Takubo, H.; Murata, N.

    1992-03-01

    Experiments are described that were conducted to examine the effects of a mobile station environment on satellite-link quality in the context of police applications. The experimental Engineering Test Satellite V (ETS-V) is described in terms of its construction, previous implementations, and the Aeronautical Maritime Experimental mobile transponder. The ETS-V experiments are designed to assess the effects of blocking materials on received input and the effects on received input at a running mobile station in different environments. A 1545-MHz beacon is employed in conjunction with a helical or a microstrip antenna depending on the experiment type, and it is shown that if a margin of 7 dB is attained the mobile communication link can provide satisfactory voice and data communications. It is shown that buildings or geological features can completely disrupt these communications by effectively blocking the radio-wave propagation path.

  16. Vocoders in mobile satellite communications

    NASA Astrophysics Data System (ADS)

    Kriedte, W.; Canavesio, F.; dal Degan, N.; Pirani, G.; Rusina, F.; Usai, P.

    Owing to the power constraints that characterize onboard transmission sections, low-bit-rate coders seem suitable for speech communications inside mobile satellite systems. Vocoders that operate at rates below 4.8 kbit/s could therefore be a desirable solution for this application, providing also the redundancy that must be added to cope with the channel error rate. After reviewing the mobile-satellite-systems aspects, the paper outlines the features of two different types of vocoders that are likely to be employed, and the relevant methods of assessing their performances. Finally, some results from computer simulations of the speech transmission systems are reported.

  17. Telemedicine using mobile satellite communication.

    PubMed

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

    1994-05-01

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

  18. 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).

  19. Mobile Aerial Tracking and Imaging System (MATrIS) for Aeronautical Research

    NASA Technical Reports Server (NTRS)

    Banks, Daniel W.; Blanchard, Robert C.; Miller, Geoffrey M.

    2004-01-01

    A mobile, rapidly deployable ground-based system to track and image targets of aeronautical interest has been developed. Targets include reentering reusable launch vehicles as well as atmospheric and transatmospheric vehicles. The optics were designed to image targets in the visible and infrared wavelengths. To minimize acquisition cost and development time, the system uses commercially available hardware and software where possible. The conception and initial funding of this system originated with a study of ground-based imaging of global aerothermal characteristics of reusable launch vehicle configurations. During that study the National Aeronautics and Space Administration teamed with the Missile Defense Agency/Innovative Science and Technology Experimentation Facility to test techniques and analysis on two Space Shuttle flights.

  20. Satellite communication and navigation for mobile users

    NASA Technical Reports Server (NTRS)

    Bernstein, S. L.

    1972-01-01

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

  1. Land mobile satellite communications systems and services

    NASA Astrophysics Data System (ADS)

    Lutz, E.

    1992-07-01

    An overview of existing and planned land mobile satellite communications systems and services is given. Operational and planned global systems such as Inmarsat, Iridium, and Globalstar, are highlighted, and the main technical details are listed. European and U.S. concepts are discussed. Applications for land mobile satellite communications are addressed, such as fleet management and global personal communications. The main technological challenges which are important for the future development of mobile communications, such as efficient use of spectrum, use of higher frequency bands, processing satellites with multiple beams, and suitable satellite orbits, are identified.

  2. 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.

  3. ACTS broadband aeronautical experiment

    NASA Technical Reports Server (NTRS)

    Abbe, Brian S.; Jedrey, Thomas C.; Estabrook, Polly; Agan, Martin J.

    1993-01-01

    In the last decade, the demand for reliable data, voice, and video satellite communication links between aircraft and ground to improve air traffic control, airline management, and to meet the growing demand for passenger communications has increased significantly. It is expected that in the near future, the spectrum required for aeronautical communication services will grow significantly beyond that currently available at L-band. In anticipation of this, JPL is developing an experimental broadband aeronautical satellite communications system that will utilize NASA's Advanced Communications Technology Satellite (ACTS) as a satellite of opportunity and the technology developed under JPL's ACTS Mobile Terminal (AMT) Task to evaluate the feasibility of using K/Ka-band for these applications. The application of K/Ka-band for aeronautical satellite communications at cruise altitudes is particularly promising for several reasons: (1) the minimal amount of signal attenuation due to rain; (2) the reduced drag due to the smaller K/Ka-band antennas (as compared to the current L-band systems); and (3) the large amount of available bandwidth. The increased bandwidth available at these frequencies is expected to lead to significantly improved passenger communications - including full-duplex compressed video and multiple channel voice. A description of the proposed broadband experimental system will be presented including: (1) applications of K/Ka-band aeronautical satellite technology to U.S. industry; (2) the experiment objectives; (3) the experiment set-up; (4) experimental equipment description; and (5) industrial participation in the experiment and the benefits.

  4. Achieving EMC Emissions Compliance for an Aeronautics Power Line Communications System

    NASA Astrophysics Data System (ADS)

    Dominiak, S.; Vos, G.; ter Meer, T.; Widmer, H.

    2012-05-01

    Transmitting data over the power distribution network - Power Line Communications (PLC) -provides an interesting solution to reducing the weight and complexity of wiring networks in commercial aircraft. One of the potential roadblocks for the introduction of this technology is achieving EMC emissions compliance. In this article an overview of the EMC conducted and radiated emissions testing for PLC- enabled aeronautics equipment is presented. Anomalies resulting from chamber resonances leading to discrepancies between the conducted emissions tests and the measured radiated emissions are identified and described. Measurements made according to the current version of the civil aeronautical EMC standard, EUROCAE ED-14F (RTCA DO-160F), show that PLC equipment can achieve full EMC emissions compliance.

  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. 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.

  7. 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.

  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. 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.

  10. 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.

  11. 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.

  12. Aeronautical Communications Research and Development Needs for Future Air Traffic Management Applications

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.

    2002-01-01

    Continuing growth in regional and global air travel has resulted in increasing traffic congestion in the air and on the ground. In spite of occasional temporary downturns due to economic recessions and catastrophic events, average growth rates of air travel have remained high since the 1960s. The resulting congestion, which constrains expansion of the air transportation industry, inflicts schedule delays and decreases overall system efficiency, creating a pressing need to develop more efficient methods of air traffic management (ATM). New ATM techniques, procedures, air space automation methods, and decision support tools are being researched and developed for deployment in time frames stretching from the next few years to the year 2020 and beyond. As these methods become more advanced and increase in complexity, the requirements for information generation, sharing and transfer among the relevant entities in the ATM system increase dramatically. However, current aeronautical communications systems will be inadequate to meet the future information transfer demands created by these advanced ATM systems. Therefore, the NASA Glenn Research Center is undertaking research programs to develop communication, methods and key technologies that can meet these future requirements. As part of this process, studies, workshops, testing and experimentation, and research and analysis have established a number of research and technology development needs. The purpose of this paper is to outline the critical research and technology needs that have been identified in these activities, and explain how these needs have been determined.

  13. Identification and Analysis of Future Aeronautical Communications Candidates: A Study of Concepts and Technologies to Support the Aeronautical Communications Needs in the NextGen and Beyond National Airspace System

    NASA Technical Reports Server (NTRS)

    Wichgers, Joel M.; Mitchell, James P.

    2015-01-01

    This report describes the results of future aeronautical communications research conducted by Rockwell Collins employees under NRA contract to NASA. The overall goal of this research was to identify and begin to evaluate communication technology candidates expected to meet the long-term aircraft-to-aircraft and aircraft-to-ground data communications needs of Air Traffic Management in the NextGen and beyond National Airspace System (NAS), considering how the NAS and communications technologies will evolve during a 50-year modernization time horizon.

  14. Mobile satellite communications - Vehicle antenna technology update

    NASA Technical Reports Server (NTRS)

    Bell, D.; Naderi, F. M.

    1986-01-01

    This paper discusses options for vehicle antennas to be used in mobile satellite communications systems. Two types of antennas are identified. A non-steerable, azimuthally omnidirectional antenna with a modest gain of 3 to 5 dBi is suggested when a low cost is desired. Alternatively, mechanically or electronically steerable antennas with a higher gain of 10 to 12 dBi are suggested to alleviate power and spectrum scarcity associated with mobile satellite communications. For steerable antennas, both open-loop and closed-loop pointing schemes are discussed. Monopulse and sequential lobing are proposed for the mechanically steered and electronically steered antennas, respectively. This paper suggests a hybrid open-loop/closed-loop pointing technique as the best performer in the mobile satellite environment.

  15. 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

  16. Western Aeronautical Test Range

    NASA Technical Reports Server (NTRS)

    Sakahara, Robert D.

    2008-01-01

    NASA's Western Aeronautical Test Range (WATR) is a network of facilities used to support aeronautical research, science missions, exploration system concepts, and space operations. The WATR resides at NASA's Dryden Flight Research Center located at Edwards Air Force Base, California. The WATR is a part of NASA's Corporate Management of Aeronautical Facilities and funded by the Strategic Capability Asset Program (SCAP). It is managed by the Aeronautics Test Program (ATP) of the Aeronautics Research Mission Directorate (ARMD) to provide the right facility at the right time. NASA is a tenant on Edwards Air Force Base and has an agreement with the Air Force Flight Test Center to use the land and airspace controlled by the Department of Defense (DoD). The topics include: 1) The WATR supports a variety of vehicles; 2) Dryden shares airspace with the AFFTC; 3) Restricted airspace, corridors, and special use areas are available for experimental aircraft; 4) WATR Products and Services; 5) WATR Support Configuration; 6) Telemetry Tracking; 7) Time Space Positioning; 8) Video; 9) Voice Communication; 10) Mobile Operations Facilities; 11) Data Processing; 12) Mission Control Center; 13) Real-Time Data Analysis; and 14) Range Safety.

  17. 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.

  18. 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.

  19. Mobile/personal communication systems in Europe

    NASA Astrophysics Data System (ADS)

    Tafazolli, R.; Evans, B. G.

    1992-03-01

    An examination is conducted of the terrestrial and satellite-based land mobile communication systems which will be developed or introduced into service in the 1990s. These systems encompass, in addition to Inmarsat standards C and M, the pan-European digital cellular radio system 'GSM', the UK's Personal Communications Network, Digital European Cordless Telecommunications, the pan-European paging system, 'PRODAT', and 'EutelTRACS'. Attention is presently given to those common aspects of these systems which can serve as bases for their further integration.

  20. Application of the aeronautical mobile satellite service (AMSS) and the providers of the service

    NASA Astrophysics Data System (ADS)

    Brangier, Francis

    1991-07-01

    The paper describes the different potential users of the AMSS, their requirements, and foreseen applications. The AMSS will be provided by several satellite-communication organizations, including INMARSAT, ARINC, SITA, and various national companies. Consideration is given to air-traffic-control services, aircraft operations communication, administrative communication, passenger communication services, and the problem of compatibility among these components.

  1. 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.

  2. New video applications on mobile communication devices

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

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

  3. Advanced communications payload for mobile applications

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  4. 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.

  5. 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.

  6. A Group Communication Approach for Mobile Computing Mobile Channel: An ISIS Tool for Mobile Services

    DTIC Science & Technology

    1994-05-01

    of mobile hosts. However, these approaches require complicated protocols for handshaking and buffering , and fault-tolerance is not often addressed. On...view layer I sis 4- channel layer -- I~•• Network Newr IVF (U°P1 VF (uUPl channel to other servers to another client Figure 1.1 MobileChannel...necessary for any communication. When multiple processes need to synchronize, a handshake of two processes introduces a handshake time, and thus, buffering

  7. 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.

  8. 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.

  9. Land vehicle antennas for satellite mobile communications

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

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

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

    NASA Astrophysics Data System (ADS)

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

    1991-09-01

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

  11. 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.

  12. L-Band Digital Aeronautical Communications System Engineering - Concepts of Use, Systems Performance, Requirements, and Architectures

    NASA Technical Reports Server (NTRS)

    Zelkin, Natalie; Henriksen, Stephen

    2010-01-01

    This NASA Contractor Report summarizes and documents the work performed to develop concepts of use (ConUse) and high-level system requirements and architecture for the proposed L-band (960 to 1164 MHz) terrestrial en route communications system. This work was completed as a follow-on to the technology assessment conducted by NASA Glenn Research Center and ITT for the Future Communications Study (FCS). ITT assessed air-to-ground (A/G) communications concepts of use and operations presented in relevant NAS-level, international, and NAS-system-level documents to derive the appropriate ConUse relevant to potential A/G communications applications and services for domestic continental airspace. ITT also leveraged prior concepts of use developed during the earlier phases of the FCS. A middle-out functional architecture was adopted by merging the functional system requirements identified in the bottom-up assessment of existing requirements with those derived as a result of the top-down analysis of ConUse and higher level functional requirements. Initial end-to-end system performance requirements were derived to define system capabilities based on the functional requirements and on NAS-SR-1000 and the Operational Performance Assessment conducted as part of the COCR. A high-level notional architecture of the L-DACS supporting A/G communication was derived from the functional architecture and requirements.

  13. L-Band Digital Aeronautical Communications System Engineering - Initial Safety and Security Risk Assessment and Mitigation

    NASA Technical Reports Server (NTRS)

    Zelkin, Natalie; Henriksen, Stephen

    2011-01-01

    This document is being provided as part of ITT's NASA Glenn Research Center Aerospace Communication Systems Technical Support (ACSTS) contract NNC05CA85C, Task 7: "New ATM Requirements--Future Communications, C-Band and L-Band Communications Standard Development." ITT has completed a safety hazard analysis providing a preliminary safety assessment for the proposed L-band (960 to 1164 MHz) terrestrial en route communications system. The assessment was performed following the guidelines outlined in the Federal Aviation Administration Safety Risk Management Guidance for System Acquisitions document. The safety analysis did not identify any hazards with an unacceptable risk, though a number of hazards with a medium risk were documented. This effort represents a preliminary safety hazard analysis and notes the triggers for risk reassessment. A detailed safety hazards analysis is recommended as a follow-on activity to assess particular components of the L-band communication system after the technology is chosen and system rollout timing is determined. The security risk analysis resulted in identifying main security threats to the proposed system as well as noting additional threats recommended for a future security analysis conducted at a later stage in the system development process. The document discusses various security controls, including those suggested in the COCR Version 2.0.

  14. Ground stations for aeronautical and space laser communications at German Aerospace Center

    NASA Astrophysics Data System (ADS)

    Moll, Florian; Shrestha, Amita; Fuchs, Christian

    2015-10-01

    Free-space laser communications are subject of current research and development in many research and industrial bodies. Long distance air-ground and space-ground can be implemented in future communication networks as feeder, backbone and backhaul links for various air- and space-based scenarios. The Institute of Communications and Navigation of the German Aerospace Center (DLR) operates two ground stations to investigate the communication channel and system: the Optical Ground Station Oberpfaffenhofen and the Transportable Optical Ground Station. The first one is a fixed installation and operated as experimental station with focus on channel measurements and tests of new developments. Various measurement devices, communication receivers and optical setups may easily be installed for different objectives. The facility is described with its dome installation, telescope setup and infrastructure. Past and current deployment in several projects is described and selected measurement achievements presented. The second ground station is developed for semi-operational use and demonstration purposes. Based on experience with the experimental ground station, this one is developed with higher level of integration and system robustness. The focus application is the space-ground and air-ground downlink of payload data from Earth observation missions. Therefore, it is also designed to be easily transportable for worldwide deployment. The system is explained and main components are discussed. The characteristics of both ground stations are presented and discussed. Further advancements in the equipment and capability are also presented.

  15. [NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 1, part 1:] Technical communications in aeronautics: Results of an exploratory study

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Glassman, Myron; Oliu, Walter E.; Barclay, Rebecca O.

    1989-01-01

    A study was undertaken that explored several aspects of technical communications in aeronautics. The study, which utilized survey research in the form of a self-administered questionnaire, was sent to 2,000 randomly selected members of the American Institute of Aeronautics and Astronautics. Six hundred and six usable questionnaires (30.3 percent) were received by the established cut off date. The study had five objectives. The first was to solicit the opinions of aeronautical engineers and scientists regarding the importance of technical communications to their profession; second, to determine their use and production of technical communications; third, to seek their views on the content of an undergraduate course in technical communications; fourth, to determine their use of libraries/technical information centers; and finally, to determine the use and importance of computer and information technology to them. The findings add considerable information to the knowledge of technical communications practices among aeronautical engineers and scientists and reinforce some of the conventional wisdom about technical communications and question other widely-held notions.

  16. Mobile Router Testing with Diverse RF Communications Links

    NASA Technical Reports Server (NTRS)

    Brooks, David; Hoder, Doug; Wilkins, Ryan

    2004-01-01

    This is a short report on demonstrations using Mobile IP and several diverse physical communications links to connect a mobile network to a fixed IPv4 internet. The first section is a description of the equipment used, followed by descriptions of the tests, the theoretical results, and finally conclusions and the actual data.

  17. Mobile e-Learning for Next Generation Communication Environment

    ERIC Educational Resources Information Center

    Wu, Tin-Yu; Chao, Han-Chieh

    2008-01-01

    This article develops an environment for mobile e-learning that includes an interactive course, virtual online labs, an interactive online test, and lab-exercise training platform on the fourth generation mobile communication system. The Next Generation Learning Environment (NeGL) promotes the term "knowledge economy." Inter-networking…

  18. Coded Modulations for Mobile Satellite Communication Channels

    NASA Astrophysics Data System (ADS)

    Rhee, Dojun

    1995-01-01

    The mobile satellite (MSAT) channel is subject to multipath fading, shadowing, Doppler frequency shift, and adjacent channel interference (ACI). Therefore, transmitted signals face severe amplitude and phase distortions. This dissertation investigates various high performance and low decoding complexity coded modulation schemes for reliable voice and data transmissions over the shadowed mobile satellite channel and the Rayleigh fading channel. The dissertation consists of four parts. The first part presents a systematic technique for constructing MPSK trellis coded modulation (TCM) codes for voice transmission over the MSAT channel. The multilevel coding method is used for constructing TCM codes using convolutional codes with good free branch distances as the component codes or using both convolutional and block codes as the component codes. Simulation results show that these codes achieve good coding gains over the uncoded reference system and outperform existing TCM codes with the same decoding complexity. In the second part, using the multilevel coding method, multilevel block coded modulation (BCM) codes are constructed for voice transmission over the MSAT channel. Even though BCM is generally less power efficient than TCM for AWGN channels, BCM has a great potential to compete with TCM in the MSAT channel because of its shorter decoding depth and hence more effective interleaving. Binary Reed -Muller (RM) codes of length up to 32 are used as component codes. Simulation results show that these codes achieve good coding gains over the uncoded reference system and outperform TCM codes with the same decoding complexity. In the third part, a simple and systematic technique for constructing multilevel concatenated BCM schemes for data transmission over the shadowed MSAT channel and the Rayleigh fading channel is presented. These schemes are designed to achieve high-performance or large coding gain with reduced decoding complexity. Construction is based on a

  19. Inferring human mobility using communication patterns.

    PubMed

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

    2014-08-22

    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.

  20. Inferring human mobility using communication patterns

    NASA Astrophysics Data System (ADS)

    Palchykov, Vasyl; Mitrović, 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. OSI-compatible protocols for mobile-satellite communications: The AMSS experience

    NASA Technical Reports Server (NTRS)

    Moher, Michael

    1990-01-01

    The protocol structure of the international aeronautical mobile satellite service (AMSS) is reviewed with emphasis on those aspects of protocol performance, validation, and conformance which are peculiar to mobile services. This is in part an analysis of what can be learned from the AMSS experience with protocols which is relevant to the design of other mobile satellite data networks, e.g., land mobile.

  6. 75 FR 8112 - In the Matter of Certain Mobile Telephones and Wireless Communication Devices Featuring Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-23

    ... COMMISSION In the Matter of Certain Mobile Telephones and Wireless Communication Devices Featuring Digital... communication devices featuring digital cameras, and components thereof by reason of infringement of certain... mobile telephones or wireless communication devices featuring digital cameras, or ] components...

  7. Increasing clinical presence of mobile communication technology: avoiding the pitfalls.

    PubMed

    Visvanathan, Akila; Gibb, Alan P; Brady, Richard R W

    2011-10-01

    Mobile communication technologies are employed in many diverse areas of healthcare delivery to provide improved quality and efficiency of communication and facilitate increased rapidity of data or information transfer. Mobile phones enable healthcare professionals to possess a portable platform from which to provide many healthcare-related applications and are a popular means to directly communicate with colleagues and patients. As involvement of mobile communication technology in healthcare delivery continues to rapidly expand, there are also important considerations of relevance to patient safety and security as a result. Here, we review the previous evidence of reported clinical risks associated with mobile communication technology, such as electromagnetic interference, confidentiality and data security, distraction/noise, infection control, and cross contamination. In conclusion, although mobile phones provide much putative potential improvement to healthcare delivery, further evaluation and research are required to both inform and protect health professionals and users of such technology in the healthcare environment and provide the evidence base to support the provision of clear and comprehensive guidelines.

  8. Satellite systems requirements for land mobile communications

    NASA Technical Reports Server (NTRS)

    Horstein, M.

    1983-01-01

    The system design objective is to provide a satellite link through a gateway station, connecting mobile users in areas not served by a terrestrial cellular system to the switched telephone network (STN). The proposed frequency allocation comprises a pair of 10-MHz bands in the 806-890 MHz range specified by the 1979 World Administrative Radio Conference (WARC) for land-mobile satellite service (LMSS). The satellite design is constrained by projected STS capability with an upper stage of the wide-body Centaur or Integral Propulsion System (IPS) type. For the latter (a TRW design), the payload is limited to approximately 10,400 lb. The design is to be based on 1990's technology, with initial operating capability scheduled for 1995. The satellite should be designed for a 7-year life. Mobile-unit compatibility with cellular system specifications is desirable, if consistent with other system requirements.

  9. Mobile Seamless Technology Enhanced CSL Oral Communication

    ERIC Educational Resources Information Center

    Lan, Yu-Ju; Lin, Yen-Ting

    2016-01-01

    The current study aimed at investigating how mobile seamless technology can be used to enhance the pragmatic competence of learners of Chinese as a second language (CSL). 34 overseas CSL learners participated in this study. They were randomly assigned into two groups: the classroom group, executing language tasks in fake contexts in a traditional…

  10. The use of mobile satellite communication terminals

    NASA Astrophysics Data System (ADS)

    Law, P. A.

    The role of small portable terminals in military satellite systems is examined; the discussion embraces terminals with an antenna reflector diameter of seven meters or less. Emphasis is placed on the specification of MARMOSET (Marconi Mobile Satellite Earth Terminal). Also considered are ship-borne satellite terminals, the improved SCOT terminal, interoperability, reduced downlink power, and reliability and availability.

  11. Mobile Adaptive Communication Support for Vocabulary Acquisition

    ERIC Educational Resources Information Center

    Epp, Carrie Demmans

    2014-01-01

    This work explores the use of an adaptive mobile tool for language learning. A school-based deployment study showed that the tool supported learning. A second study is being conducted in informal learning environments. Current work focuses on building models that increase our understanding of the relationship between application usage and learning.

  12. ACTS Mobile Terminals

    NASA Technical Reports Server (NTRS)

    Abbe, Brian S.; Agan, Martin J.; Jedrey, Thomas C.

    1997-01-01

    The development of the Advanced Communications Technology Satellite (ACTS) Mobile Terminal (AMT) and its follow-on, the Broadband Aeronautical Terminal (BAT), have provided an excellent testbed for the evaluation of K- and Ka-band mobile satellite communications systems. An overview of both of these terminals is presented in this paper.

  13. 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.

  14. [NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 1, part 2:] Technical communications in aeronautics: Results of an exploratory study

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Glassman, Myron; Oliu, Walter E.; Barclay, Rebecca O.

    1989-01-01

    A study was undertaken that explored several aspects of technical communications in aeronautics. The study, which utilized survey research in the form of a self-administered questionnaire, was sent to 2,000 randomly selected members of the American Institute of Aeronautics and Astronautics. Six hundred and six usable questionnaires (30.3 percent) were received by the established cut off date. Part 2 of this study lists appendices to part 1, including survey instrument, aggregate totals, cross tabulations, and open-ended comments.

  15. 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.

  16. Optical fiber feeder for microcellular mobile communication systems (H-015)

    NASA Astrophysics Data System (ADS)

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

    1993-09-01

    This paper investigates the feasibility of using an optical fiber feeder for microcellular mobile communication systems. The optical feeder enables compact and low-cost base stations, easy radio channel control, and flexible mobile communication systems. Basic transmission characteristics were investigated through optical transmission experiments. By using these results, it has been estimated that the optical feeder can transmit 880 telephone channels for digital TDM systems and 2000 channels for analog FDM systems through 20 km of optical fiber. Furthermore, two kinds of novel techniques, which enlarge dynamic range of the optical feeder, are reported.

  17. Space Mobile Network: A Near Earth Communication and Navigation Architecture

    NASA Technical Reports Server (NTRS)

    Israel, Dave J.; Heckler, Greg; Menrad, Robert J.

    2016-01-01

    This paper describes a Space Mobile Network architecture, the result of a recently completed NASA study exploring architectural concepts to produce a vision for the future Near Earth communications and navigation systems. The Space Mobile Network (SMN) incorporates technologies, such as Disruption Tolerant Networking (DTN) and optical communications, and new operations concepts, such as User Initiated Services, to provide user services analogous to a terrestrial smartphone user. The paper will describe the SMN Architecture, envisioned future operations concepts, opportunities for industry and international collaboration and interoperability, and technology development areas and goals.

  18. 5G: rethink mobile communications for 2020+.

    PubMed

    Chih-Lin, I; Han, Shuangfeng; Xu, Zhikun; Sun, Qi; Pan, Zhengang

    2016-03-06

    The 5G network is anticipated to meet the challenging requirements of mobile traffic in the 2020s, which are characterized by super high data rate, low latency, high mobility, high energy efficiency and high traffic density. This paper provides an overview of China Mobile's 5G vision and potential solutions. Three key characteristics of 5G are analysed, i.e. super fast, soft and green. The main 5G R&D themes are further elaborated, which include five fundamental rethinkings of the traditional design methodologies. The 5G network design considerations are also discussed, with cloud radio access network, ultra-dense network, software defined network and network function virtualization examined as key potential solutions towards a green and soft 5G network. The paradigm shift to user-centric network operation from the traditional cell-centric operation is also investigated, where the decoupled downlink and uplink, control and data, and adaptive multiple connections provide sufficient means to achieve a user-centric 5G network with 'no more cells'. The software defined air interface is investigated under a uniform framework and can adaptively adapt the parameters to well satisfy various requirements in different 5G scenarios.

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

    ERIC Educational Resources Information Center

    Romich, Barry A.; Vagnini, Carol B.

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

  20. 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).

  1. 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.

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

    PubMed

    Hoy, Matthew B

    2013-01-01

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

  3. Daily Rhythms in Mobile Telephone Communication

    PubMed Central

    Aledavood, Talayeh; López, Eduardo; 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 were typically focused on a small number of emotionally intense relationships. These results demonstrate that individual differences in circadian rhythms are not just related to broad patterns of morningness and eveningness, but have a strong social component, in directing phone calls to specific individuals at specific times of day. PMID:26390215

  4. 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.

  5. 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.

  6. 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…

  7. 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.

  8. 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.

  9. Communication skills for mobile remote presence technology in clinical interactions.

    PubMed

    Nestel, Debra; Sains, Parvinder; Wetzel, Cordula M; Nolan, Carmel; Tay, Ann; Kneebone, Roger L; Darzi, Ara W

    2007-01-01

    The use of mobile robotic units for teleconsultation means that the clinician's cognitive and attention skills are divided between tele-operation of the robotic unit and the consultation with the patient. We developed a communication guide based on evidence-based patient-centred interviewing and telephone conferencing skills. The communication guide was tested by five trainee surgeons in a pre- and post-test design. Each surgeon completed three simulated patient consultations. After reading the communication guide, trainees completed three further consultations. The trainees rated authenticity, degree of difficulty, familiarity of clinical presentation and confidence in using telepresence to manage the consultations. Their mean scores were 3.0-4.6, 2.2-4.0, 4.4-4.8 and 3.2-4.2 respectively (maximum possible score 5). The simulated patients rated their satisfaction with communication. Their ratings suggested that there were areas for communication skills development with mean scores ranging from 8.2 to 11.4 (maximum possible score = 15). Although we do not yet know enough about communicating with real patients using mobile robotic units, the communication guide appeared to be useful in our simulated interactions.

  10. 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.

  11. [Communicative process in the mobile emergency service (SAMU/192)].

    PubMed

    dos Santos, Maria Claudia; Bernardes, Andrea; Gabriel, Carmen Silvia; Evora, Yolanda Dora Martinez; Rocha, Fernanda Ludmilla Rossi

    2012-03-01

    This study aims to characterize the communication process among nursing assistants who work in vehicles of the basic life support of the mobile emergency service, in the coordination of this service, and in the unified medical regulation service in a city of the state of São Paulo, Brazil. This descriptive and qualitative research used the thematic content analysis for data analysis. Semi-structured interviews were used for the data collection, which was held in January, 2010. Results show diffculties in communication with both the medical regulation service and the coordination. Among the most highlighted aspects are failures during the radio transmission, lack of qualified radio operators, difficult access to the coordination and lack of supervision by nurses. However, it was possible to detect solutions that aim to improve the communication ana consequently, the service offered by the mobile emergency service.

  12. Communicate to Learn, Learn to Communicate: A Study of Engineering Students' Communication Strategies in a Mobile-Assisted Learning Environment

    ERIC Educational Resources Information Center

    Cheng, Li; Lu, Zhihong

    2016-01-01

    This paper reports a 3-month study investigating engineering students' Communication Strategies (CSs) in a mobile-assisted course. 67 Chinese learners of English in this course volunteered to participate in the study. The instruments included oral communication sessions, stimulated recall interviews, WeChat exchanges, etc. Results showed that the…

  13. 78 FR 34132 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof... Communications Devices, Including Mobile Phones and Components Thereof, DN 2958; the Commission...

  14. 75 FR 44282 - In the Matter of Certain Mobile Telephones and Wireless Communication Devices Featuring Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-28

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION In the Matter of Certain Mobile Telephones and Wireless Communication Devices Featuring Digital... importation of certain mobile telephones and wireless communication devices featuring digital cameras,...

  15. Communication in critical care environments: mobile telephones improve patient care.

    PubMed

    Soto, Roy G; Chu, Larry F; Goldman, Julian M; Rampil, Ira J; Ruskin, Keith J

    2006-02-01

    Most hospital policies prohibiting the use of wireless devices cite reports of disruption of medical equipment by cellular telephones. There have been no studies to determine whether mobile telephones may have a beneficial impact on safety. At the 2003 meeting of the American Society of Anesthesiologists 7878 surveys were distributed to attendees. The five-question survey polled anesthesiologists regarding modes of communication used in the operating room/intensive care unit and experience with communications delays and medical errors. Survey reliability was verified using test-retest analysis and proportion agreement in a convenience sample of 17 anesthesiologists. Four-thousand-eighteen responses were received. The test-retest reliability of the survey instrument was excellent (Kappa = 0.75; 95% confidence interval, 0.56-0.94). Sixty-five percent of surveyed anesthesiologists reported using pagers as their primary mode of communications, whereas only 17% used cellular telephones. Forty-five percent of respondents who use pagers reported delays in communications compared with 31% of cellular telephone users. Cellular telephone use by anesthesiologists is associated with a reduction in the risk of medical error or injury resulting from communication delay (relative risk = 0.78; 95% confidence interval, 0.6234-0.9649). The small risks of electromagnetic interference between mobile telephones and medical devices should be weighed against the potential benefits of improved communication.

  16. 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.

  17. Protocol design for mobile radio group communications over satellite

    NASA Astrophysics Data System (ADS)

    Leung, Victor C. M.

    1992-10-01

    The protocol design for a mobile radio service supporting half-duplex push-to-talk voice communications over mobile satellite systems is presented. Two types of protocols are considered, namely, a demand assignment multiple access protocol to assign channels only to those user groups in active sessions of conversations and a signaling protocol to arbitrate contentions among members of the same user group within an assigned channel. It is concluded that the proposed access control protocol makes it possible to improve the throughput capacity of the assigned channel by 65 or 18 percent compared to manual carrier-sensed access without or with collisoin detection, respectively.

  18. 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.

  19. 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

  20. Structure and tie strengths in mobile communication networks.

    PubMed

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

    2007-05-01

    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.

  1. 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.

  2. 76 FR 63657 - Certain Devices for Mobile Data Communication; Notice of Institution of Investigation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-13

    ... devices for mobile data communication by reason of infringement of certain claims of U.S. Patent No. 6,233... certain devices for mobile data communication that infringe one or more of claims 1, 3, 5- 9, 33-36, and... Mobile Data Communication; Notice of Institution of Investigation; Institution of Investigation...

  3. 75 FR 3914 - Recordation of Trade Name “Sony Ericsson Mobile Communications AB”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ... SECURITY U.S. Customs and Border Protection Recordation of Trade Name ``Sony Ericsson Mobile Communications... action. SUMMARY: This document gives notice that ``Sony Ericsson Mobile Communications AB'' has been recorded with CBP as a trade name by Sony Ericsson Mobile Communications AB. The application for trade...

  4. 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).

  5. Phased-Array Satcom Antennas Developed for Aeronautical Applications

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.

    2001-01-01

    The Advanced Communications (AC) for Aeronautics research at the NASA Glenn Research Center integrates both aeronautics and space communications technologies to achieve the national objective of upgrading the present National Airspace System infrastructure by responding to the agency's aviation capacity and safety goals. One concept for future air traffic management, free flight, presents a significantly increased demand for communications systems capacity and performance in comparison to current air traffic management practices. Current aeronautical communications systems are incapable of supporting the anticipated demands, and the new digital data communications links that are being developed, or are in the early stages of implementation, are not primarily designed to carry the data-intensive free flight air traffic management (ATM) communications loads. Emerging satellite communications technologies are the best potential long-term solution to provide the capacity and performance necessary to enable a mature free flight concept to be deployed. NASA AC/ATM funded the development of a Boeing-designed Ku-band transmit phased-array antenna, a combined in-house and contract effort. Glenn designed and integrated an Aeronautical Mobile Satellite Communications terminal based on the transmit phased-array antenna and a companion receive phased-array antenna previously developed by Boeing.

  6. 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.

  7. Advanced Civilian Aeronautical Concepts

    NASA Technical Reports Server (NTRS)

    Bushnell, Dennis M.

    1996-01-01

    Paper discusses alternatives to currently deployed systems which could provide revolutionary improvements in metrics applicable to civilian aeronautics. Specific missions addressed include subsonic transports, supersonic transports and personal aircraft. These alternative systems and concepts are enabled by recent and envisaged advancements in electronics, communications, computing and Designer Fluid Mechanics in conjunction with a design approach employing extensive synergistic interactions between propulsion, aerodynamics and structures.

  8. A new satellite system for land mobile communications at EHF

    NASA Astrophysics Data System (ADS)

    Ruggieri, Marina; Valdoni, Francesco; Vatalaro, Francesco

    1990-10-01

    An architecture for a mobile satellite system proposed for integration with the pan-European GSM terrestrial cellular system is described. A cellular satellite system concept is outlined with emphasis on multispot coverage of the cell, and a carrier-to-interference analysis is performed. It is noted that a suitable payload structure is needed to allow the flexible management of the channels assigned to a certain cell, and a multiport transponder (MPT) payload architecture is introduced, where an MPT is a wideband transparent multibeam cell-transponder provided with an intrinsic soft-fail capability. A proposal for a comprehensive program encompassing an experiment including a propagation mission and a communication mission is discussed, and attention is focused on experiments with highly inclined orbit mobile-radio channels, statistical channel models, and mobile-terminal terrain antenna.

  9. 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.

  10. Aeronautic instruments

    NASA Technical Reports Server (NTRS)

    Everling, E; Koppe, H

    1924-01-01

    The development of aeronautic instruments. Vibrations, rapid changes of the conditions of flight and of atmospheric conditions, influence of the air stream all call for particular design and construction of the individual instruments. This is shown by certain examples of individual instruments and of various classes of instruments for measuring pressure, change of altitude, temperature, velocity, inclination and turning or combinations of these.

  11. FQPSK techniques for satellite and mobile radio communications systems

    NASA Astrophysics Data System (ADS)

    Li, Yazhuo; Tang, Jing; Tao, Xiaofeng

    2005-11-01

    A continuous phase modulation (CPM) and constant envelope modulation (CEM) alternative of Feher-Patented quadrature phase-shift keying (FQPSK) modulation technique is presented. It is found to provide good spectral efficiencies, power efficiencies, and bit error rate (BER) performance. The modulation schemes of FQPSK are described. The spectral efficiencies, BER performance are also compared with FQPSK and other modulation techniques which are widely used in current mobile and cordless radio standards. The results show that FQPSK modulated signal exhibits much less spectrum spreading than QPSK, OQPSK, and MSK, and the error probability performance of the FQPSK is superior to those in narrow-band nonlinear channels. Based on that, the system capacity and power dissipation are also analyzed for communication systems. It is found that the encoder or receiver for the FQPSK signal to be fully compatible with original I/Q modulated one. FQPSK technique is suitable for nonlinear channels, such as satellite and mobile communications systems reducing the AM/AM and AM/PM adverse effects. At last it is also attempted to extend the application in 3G (CDMA) and 4G (OFDM) mobile communications systems.

  12. Continuous zoom antenna for mobile visible light communication.

    PubMed

    Zhang, Xuebin; Tang, Yi; Cui, Lu; Bai, Tingzhu

    2015-11-10

    In this paper, we design a continuous zoom antenna for mobile visible light communication (VLC). In the design, a right-angle reflecting prism was adopted to fold the space optical path, thus decreasing the antenna thickness. The surface of each lens in the antenna is spherical, and the system cost is relatively low. Simulation results indicated that the designed system achieved the following performance: zoom ratio of 2.44, field of view (FOV) range of 18°-48°, system gain of 16.8, and system size of 18 mm×6  mm. Finally, we established an indoor VLC system model in a room the size of 5  m ×5  m ×3  m and compared the detection results of the zoom antenna and fixed-focus antenna obtained in a multisource communication environment, a mobile VLC environment, and a multiple-input multiple-output communication environment. The simulation results indicated that the continuous zoom antenna could realize large FOV and high gain. Moreover, the system showed improved stability, mobility, and environmental applicability.

  13. 47 CFR 25.216 - Limits on emissions from mobile earth stations for protection of aeronautical radionavigation...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... any 2 millisecond active transmission interval. (h) Mobile earth stations manufactured more than six... not exceed −70 dBW/MHz, averaged over any 2 millisecond active transmission interval, in the band 1559... stations shall not exceed −80 dBW, averaged over any 2 millisecond active transmission interval, in...

  14. 47 CFR 25.216 - Limits on emissions from mobile earth stations for protection of aeronautical radionavigation...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... any 2 millisecond active transmission interval. (h) Mobile earth stations manufactured more than six... not exceed −70 dBW/MHz, averaged over any 2 millisecond active transmission interval, in the band 1559... stations shall not exceed −80 dBW, averaged over any 2 millisecond active transmission interval, in...

  15. 47 CFR 25.216 - Limits on emissions from mobile earth stations for protection of aeronautical radionavigation...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... any 2 millisecond active transmission interval. (h) Mobile earth stations manufactured more than six... not exceed −70 dBW/MHz, averaged over any 2 millisecond active transmission interval, in the band 1559... stations shall not exceed −80 dBW, averaged over any 2 millisecond active transmission interval, in...

  16. 47 CFR 25.216 - Limits on emissions from mobile earth stations for protection of aeronautical radionavigation...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... any 2 millisecond active transmission interval. (h) Mobile earth stations manufactured more than six... not exceed −70 dBW/MHz, averaged over any 2 millisecond active transmission interval, in the band 1559... stations shall not exceed −80 dBW, averaged over any 2 millisecond active transmission interval, in...

  17. 47 CFR 25.216 - Limits on emissions from mobile earth stations for protection of aeronautical radionavigation...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... any 2 millisecond active transmission interval. (h) Mobile earth stations manufactured more than six... not exceed −70 dBW/MHz, averaged over any 2 millisecond active transmission interval, in the band 1559... stations shall not exceed −80 dBW, averaged over any 2 millisecond active transmission interval, in...

  18. 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

  19. An Aeronautical-Mobile 20/30 GHz Satellite-Tracking Antenna for High Data Rate Satcom

    NASA Technical Reports Server (NTRS)

    Densmore, A.; Guler, M.

    1995-01-01

    An antenna for use on an aircraft has been developed and tested for transmissions to and from a communications satellite. The antenna operates at 20/30 GHz and a data rate of 512 kbps, and it does not require modifying the shape of the aircraft fuselage.

  20. 78 FR 32689 - Certain Portable Electronic Communications Devices, Including Mobile Phones and Components...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ... COMMISSION Certain Portable Electronic Communications Devices, Including Mobile Phones and Components Thereof..., Including Mobile Phones and Components Thereof, DN 2958; the Commission is soliciting comments on any public... communications devices, including mobile phones and components thereof. The complaint names as respondents...

  1. 77 FR 35336 - Privacy and Security of Information Stored on Mobile Communications Devices

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    ... COMMISSION 47 CFR Part 64 Privacy and Security of Information Stored on Mobile Communications Devices AGENCY... privacy and data security practices of mobile wireless services providers with respect to customer information stored on their users' mobile communications devices. In addition, the document seeks comment...

  2. 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.

  3. Aeronautics and space report of the President: 1981 activities

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Achievements in the aeronautics and space program by function are summarized. Activities in communications, Earth's resources and environment, space science, space transportation, international activities, and aeronautics are included.

  4. 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…

  5. Performance of a Regional Aeronautical Telecommunications Network

    NASA Technical Reports Server (NTRS)

    Bretmersky, Steven C.; Ripamonti, Claudio; Konangi, Vijay K.; Kerczewski, Robert J.

    2001-01-01

    This paper reports the findings of the simulation of the ATN (Aeronautical Telecommunications Network) for three typical average-sized U.S. airports and their associated air traffic patterns. The models of the protocols were designed to achieve the same functionality and meet the ATN specifications. The focus of this project is on the subnetwork and routing aspects of the simulation. To maintain continuous communication between the aircrafts and the ground facilities, a model based on mobile IP is used. The results indicate that continuous communication is indeed possible. The network can support two applications of significance in the immediate future FTP and HTTP traffic. Results from this simulation prove the feasibility of development of the ATN concept for AC/ATM (Advanced Communications for Air Traffic Management).

  6. A review of earth observation using mobile personal communication devices

    NASA Astrophysics Data System (ADS)

    Ferster, Colin J.; Coops, Nicholas C.

    2013-02-01

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

  7. Space Mobile Network: A Near Earth Communications and Navigation Architecture

    NASA Technical Reports Server (NTRS)

    Israel, David J.; Heckler, Gregory W.; Menrad, Robert J.

    2016-01-01

    This paper shares key findings of NASA's Earth Regime Network Evolution Study (ERNESt) team resulting from its 18-month effort to define a wholly new architecture-level paradigm for the exploitation of space by civil space and commercial sector organizations. Since the launch of Sputnik in October 1957 spaceflight missions have remained highly scripted activities from launch through disposal. The utilization of computer technology has enabled dramatic increases in mission complexity; but, the underlying premise that the diverse actions necessary to meet mission goals requires minute-by-minute scripting, defined weeks in advance of execution, for the life of the mission has remained. This archetype was appropriate for a "new frontier" but now risks overtly constraining the potential market-based opportunities for the innovation considered necessary to efficiently address the complexities associated with meeting communications and navigation requirements projected to be characteristics of the next era of space exploration: a growing number of missions in simultaneous execution, increased variance of mission types and growth in location/orbital regime diversity. The resulting ERNESt architectural cornerstone - the Space Mobile Network (SMN) - was envisioned as critical to creating an environment essential to meeting these future challenges in political, programmatic, technological and budgetary terms. The SMN incorporates technologies such as: Disruption Tolerant Networking (DTN) and optical communications, as well as new operations concepts such as User Initiated Services (UIS) to provide user services analogous to today's terrestrial mobile network user. Results developed in collaboration with NASA's Space Communications and Navigation (SCaN) Division and field centers are reported on. Findings have been validated via briefings to external focus groups and initial ground-based demonstrations. The SMN opens new niches for exploitation by the marketplace of mission

  8. 75 FR 65654 - In the Matter of: Certain Mobile Telephones and Wireless Communication Devices Featuring Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-26

    ... From the Federal Register Online via the Government Publishing Office ] INTERNATIONAL TRADE COMMISSION In the Matter of: Certain Mobile Telephones and Wireless Communication Devices Featuring Digital... and wireless communication devices featuring digital cameras, and components thereof, that...

  9. [Exploring Aeronautics

    NASA Technical Reports Server (NTRS)

    Robinson, Brandi

    2004-01-01

    This summer I have been working with the N.A.S.A. Project at Cuyahoga Community College (Tri-C) under the title of Exploring Aeronautics Project Leader. The class that I have worked with is comprised of students that will enter the eighth grade in the fall of 2004. The program primarily focuses upon math proficiency and individualized class projects. My duties have encompassed both realms. During the first 2-3 weeks of my internship, I worked at NASA Glenn Research Center (GRC) researching, organizing, and compiling information for weekly Scholastic Challenges and the Super Scholastic Challenge. I was able to complete an overview of Scholastic Challenge and staff responsibilities regarding the competition; a proposal for an interactive learning system, Quizdom; a schedule for challenge equipment, as well as a schedule listing submission deadlines for the staff. Also included in my tasks, during these first 2-3 weeks, were assisting Tammy Allen and Candice Thomas with the student application review and interview processes for student applicants. For the student and parent orientation, I was assigned publications and other varying tasks to complete before the start of the program. Upon the commencement of the program, I changed location from NASA GRC to Tri-C Metro Campus, where student classes for the Cleveland site are held. During the duration of the program, I work with the instructor for the Exploring Aeronautics class, kkkk, assisting in classroom management, daily attendance, curriculum, project building, and other tasks as needed. These tasks include the conducting of the weekly competition, known as Scholastic Challenge. As a Project Leader, I am also responsible for one subject area of the Scholastic Challenge aspect of the N.A.S.A. Project curriculum. Each week I have to prepare a mission that the participants will take home the following Monday and at least 10 questions that will be included in the pool of questions used for the Scholastic Challenge

  10. A mobile phone-based Communication Support System for elderly persons.

    PubMed

    Ogawa, Hidekuni; Yonezawa, Yoshiharu; Maki, Hiromichi; Caldwell, W Morton

    2007-01-01

    A mobile phone-based communication support system has been developed for assisting elderly people to communicate by mobile phone. The system consists of a low power mobile phone (PHS phone) having a large liquid crystal screen. When an elderly person telephones, they then choose a communication person from registered support personnel pictures displayed on the liquid crystal screen. The PHS phone dials that person automatically. The elderly person can therefore easily recognize and verify the person. The newly-developed communication support system assists a significant percentage of elderly people with poor eyesight and memory, which frequently cause communication problems, such as dialing a wrong number.

  11. 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.

  12. Speech coding at 4800 bps for mobile satellite communications

    NASA Astrophysics Data System (ADS)

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

    1988-05-01

    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.

  13. 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.

  14. Nationwide Mobile Communication Systems. Volume 3. Appendix B - D

    DTIC Science & Technology

    1990-06-01

    34 ’U- COPY NAVAL POSTGRADUATE SCHOOL 00> Monterey, California CV) N F.L-FATT -’ -m% DTIC THESIS A U I" 0 NATIONWIDE MOBILE COMMUNICATION SYSTEMS by...the radio spectrum. Frequency jub-bands are also designated by the letters listed in Talble 31 [Ref. 52:pp. 212-213]. 492 o o >1 0 0 V z -- >1 u ra r- o...01 0J U u a .40 4- 0 0 r 4- - -4 So a -4 HM P4 49 3 TABLE 31 LETTER BAND DESIGNATIONS Band Frequency RanQe C 3.7-6.425 GHz K 10.7-18 GHz K8 18-304

  15. An introduction to Doppler effect and fading in mobile communications

    NASA Astrophysics Data System (ADS)

    Depaula, Abdon B.

    1992-12-01

    In this research we present an introductory analysis of a complex aspect of mobile communications: Doppler effect is evaluated in both Ricean and Rayleigh channels. A noncoherent 2-FSK scheme is selected to evaluate the behavior of the system under very strong fading channel conditions. The analysis is conducted for the binary case due to the possibility of developing closed form solutions. Therefore, the approach is simplified avoiding long lasting simulations that may obscure the concepts. The probability of bit error for the 2-FSK case can also be used as an initial bound for a M-FSK scheme. Diversity is evaluated as a means of combating fading and Doppler effects. Error correcting codes, in the form of a convolutional codes, are also used and applied to both effects.

  16. 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.

  17. 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.

  18. 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.

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

    PubMed

    Tan, Yee-Yong; Chung, Wan-Young

    2014-01-01

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

  20. 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

    ... COMMISSION Certain Devices for Mobile Data Communication; Determination Not To Review an Initial..., and the sale within the United States after importation of certain devices for mobile data communication by reason of infringement of certain claims of United States Patent Nos. 6,233,608; 6,289,212;...

  1. 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

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Devices for Mobile Data Communication; Notice of Commission Determination Not To Review an... importation of certain devices for mobile data communication by reason of infringement of various claims...

  2. Anytime-Anywhere? Mobile Communicative Practices and the Management of Relationships in Everyday Life

    ERIC Educational Resources Information Center

    Moreno Becerra, Tabita Alejandra

    2015-01-01

    The present study examines how mobile practices of social-media use are integrated into individuals' everyday lives as a way to manage their relationships. Mobile communication technologies and social-media use intersect in people's everyday communicative practices, allowing individuals to engage in continuous interactions that take place on the…

  3. 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.…

  4. 77 FR 43858 - Certain Mobile Telephones and Wireless Communication Devices Featuring Digital Cameras, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-26

    ... COMMISSION Certain Mobile Telephones and Wireless Communication Devices Featuring Digital Cameras, and... States after importation of certain mobile telephones and wireless communication devices featuring digital cameras, and components thereof, that infringe certain claims of U.S. Patent No. 6,292,218...

  5. 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

    ... COMMISSION Certain Personal Data and Mobile Communications Devices and Related Software; Institution of a... April 6, 2010, based on a complaint filed by Apple Inc., and its subsidiary NeXT Software, Inc., both of... mobile communications devices and related software. 75 FR 17434 (Apr. 6, 2010). The complaint named...

  6. 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.

  7. 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.

  8. 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

  9. Adaptive digital beamforming for a CDMA mobile communications payload

    NASA Astrophysics Data System (ADS)

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

    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

  10. Perspectives of a mobile application for people with communication disabilities in the community.

    PubMed

    Crook, Alice; Kenny, Julie; Johnson, Hilary; Davidson, Bronwyn

    2017-02-01

    Purpose To determine the perceptions of people with complex communication needs (CCN) and business staff regarding the uses and functionality of a mobile application to aid communication access. Method A qualitative study using thematic analysis of transcripts and field notes from focus groups and interviews of 19 people with CCN and nine business staff. Results Four themes and 10 subthemes were drawn from the data. Themes highlighted the desire for: increased communication strategies to support customer interactions, increased access to information, functionality of a mobile application to increase its utility, and preferred technical and visual features of mobile applications. Conclusion People with CCN and business staff perceived a mobile application as a useful tool to aid communication access. This research highlighted the importance of facilitating strategies to communicative interactions and information in the community as the fundamental goal of a mobile application developed to support communication access. Implications for Rehabilitation Mobile applications are widely accepted and used in modern customer service industries and have been identified as tools to increase communication access for people with complex communication needs (CCN). People with CCN identified accessibility, presentation, and customisation as important features of mobile applications for communication access. The diversity of user preferences and needs, and the rapid development of new technologies limit the applicability of a single design for mobile applications for people with CCN. People with CCN should be involved in application design and development. A mobile application for communication access would support customer-business interactions as well as enable more accessible information sharing about disability needs and services.

  11. Directedness of information flow in mobile phone communication networks.

    PubMed

    Peruani, Fernando; Tabourier, Lionel

    2011-01-01

    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 allowing the existence of information loops, they also promote information spreading. Temporal correlations, and therefore causality effects, are only visible as local phenomena and during short time scales. Consequently, the very idea that there is (intentional) information spreading beyond a small vecinity is called into question. These results are obtained through a combination of theory and data analysis techniques.

  12. Proceedings of the Fourth International Mobile Satellite Conference (IMSC 1995)

    NASA Technical Reports Server (NTRS)

    Rigley, Jack R. (Compiler); Estabrook, Polly (Compiler); Reekie, D. Hugh M. (Editor)

    1995-01-01

    The theme to the 1995 International Mobile Satellite Conference was 'Mobile Satcom Comes of Age'. The sessions included Modulation, Coding, and Multiple Access; Hybrid Networks - 1; Spacecraft Technology; propagation; Applications and Experiments - 1; Advanced System Concepts and Analysis; Aeronautical Mobile Satellite Communications; Mobile Terminal Antennas; Mobile Terminal Technology; Current and Planned Systems; Direct Broadcast Satellite; The Use of CDMA for LEO and ICO Mobile Satellite Systems; Hybrid Networks - 2; and Applications and Experiments - 2.

  13. Big Data Analytics for Disaster Preparedness and Response of Mobile Communication Infrastructure during Natural Hazards

    NASA Astrophysics Data System (ADS)

    Zhong, L.; Takano, K.; Ji, Y.; Yamada, S.

    2015-12-01

    The disruption of telecommunications is one of the most critical disasters during natural hazards. As the rapid expanding of mobile communications, the mobile communication infrastructure plays a very fundamental role in the disaster response and recovery activities. For this reason, its disruption will lead to loss of life and property, due to information delays and errors. Therefore, disaster preparedness and response of mobile communication infrastructure itself is quite important. In many cases of experienced disasters, the disruption of mobile communication networks is usually caused by the network congestion and afterward long-term power outage. In order to reduce this disruption, the knowledge of communication demands during disasters is necessary. And big data analytics will provide a very promising way to predict the communication demands by analyzing the big amount of operational data of mobile users in a large-scale mobile network. Under the US-Japan collaborative project on 'Big Data and Disaster Research (BDD)' supported by the Japan Science and Technology Agency (JST) and National Science Foundation (NSF), we are going to investigate the application of big data techniques in the disaster preparedness and response of mobile communication infrastructure. Specifically, in this research, we have considered to exploit the big amount of operational information of mobile users for predicting the communications needs in different time and locations. By incorporating with other data such as shake distribution of an estimated major earthquake and the power outage map, we are able to provide the prediction information of stranded people who are difficult to confirm safety or ask for help due to network disruption. In addition, this result could further facilitate the network operators to assess the vulnerability of their infrastructure and make suitable decision for the disaster preparedness and response. In this presentation, we are going to introduce the

  14. Interoperability framework for communication between processes running on different mobile operating systems

    NASA Astrophysics Data System (ADS)

    Gal, A.; Filip, I.; Dragan, F.

    2016-02-01

    As we live in an era where mobile communication is everywhere around us, the necessity to communicate between the variety of the devices we have available becomes even more of an urge. The major impediment to be able to achieve communication between the available devices is the incompatibility between the operating systems running on these devices. In the present paper we propose a framework that will make possible the ability to inter-operate between processes running on different mobile operating systems. The interoperability process will make use of any communication environment which is made available by the mobile devices where the processes are installed. The communication environment is chosen so as the process is optimal in terms of transferring the data between the mobile devices. The paper defines the architecture of the framework, expanding the functionality and interrelation between modules that make up the framework. For the proof of concept, we propose to use three different mobile operating systems installed on three different types of mobile devices. Depending on the various factors related to the structure of the mobile devices and the data type to be transferred, the framework will establish a data transfer protocol that will be used. The framework automates the interoperability process, user intervention being limited to a simple selection from the options that the framework suggests based on the full analysis of structural and functional elements of the mobile devices used in the process.

  15. 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.

  16. Virtual acoustics, aeronautics, and communications.

    PubMed

    Begault, D R

    1998-06-01

    An optimal approach to auditory display design for commercial aircraft would utilize both spatialized (3-D) audio techniques and active noise cancellation for safer operations. Results from several aircraft simulator studies conducted at NASA Ames Research Center are reviewed, including Traffic alert and Collision Avoidance System (TCAS) warnings, spoken orientation "beacons" for gate identification and collision avoidance on the ground, and hardware for improved speech intelligibility. The implications of hearing loss among pilots is also considered.

  17. Virtual acoustics, aeronautics, and communications

    NASA Technical Reports Server (NTRS)

    Begault, D. R.; Wenzel, E. M. (Principal Investigator)

    1998-01-01

    An optimal approach to auditory display design for commercial aircraft would utilize both spatialized (3-D) audio techniques and active noise cancellation for safer operations. Results from several aircraft simulator studies conducted at NASA Ames Research Center are reviewed, including Traffic alert and Collision Avoidance System (TCAS) warnings, spoken orientation "beacons" for gate identification and collision avoidance on the ground, and hardware for improved speech intelligibility. The implications of hearing loss among pilots is also considered.

  18. Virtual Acoustics, Aeronautics and Communications

    NASA Technical Reports Server (NTRS)

    Begault, Durand R.; Null, Cynthia H. (Technical Monitor)

    1996-01-01

    An optimal approach to auditory display design for commercial aircraft would utilize both spatialized ("3-D") audio techniques and active noise cancellation for safer operations. Results from several aircraft simulator studies conducted at NASA Ames Research Center are reviewed, including Traffic alert and Collision Avoidance System (TCAS) warnings, spoken orientation "beacons" for gate identification and collision avoidance on the ground, and hardware for improved speech intelligibility. The implications of hearing loss amongst pilots is also considered.

  19. Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

    NASA Technical Reports Server (NTRS)

    Huck, R. W. (Compiler); Rafferty, William (Compiler); Reekie, D. Hugh M. (Editor)

    1990-01-01

    Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression.

  20. [Change settings for visual analyzer of child users of mobile communication: longitudinal study].

    PubMed

    Khorseva, N I; Grigor'ev, Iu G; Gorbunova, N V

    2014-01-01

    The paper represents theresults of longitudinal monitoring of the changes in the parameters of simple visual-motor reaction, the visual acuity and the rate of the visual discrimination in the child users of mobile communication, which indicate the multivariability of the possible effects of radiation from mobile phones on the auditory system of children.

  1. 78 FR 69018 - Improving the Resiliency of Mobile Wireless Communications Networks; Reliability and Continuity...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ...In this document, the Federal Communications Commission seeks comment on measures to promote the resiliency and transparency of mobile wireless networks. This document considers and seeks comment on, among other measures, a requirement that mobile wireless network providers report for public disclosure on a daily basis during major disasters the percentages of their cell sites that are......

  2. 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.

  3. 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.

  4. Fundamental Aeronautics Program

    NASA Technical Reports Server (NTRS)

    Misra, Ajay

    2009-01-01

    The Overarching Mission of NASA's Aeronautics Research Mission Directorate (ARMD) is: To advance U.S. technological leadership in aeronautics in partnership with industry, academia, and other government agencies that conduct aeronautics-related research. ARMD supports the Agency's goal of developing a balanced overall program of science, exploration, and aeronautics, and ARMD's research plans also directly support the National Aeronautics R&D Policy and accompanying Executive Order 131419.

  5. 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.

  6. Reducing Communication Detection and Eavesdropping using Mobile Agent Relay Networks

    DTIC Science & Technology

    2010-12-01

    to maintain a wireless network to support the users. This type of solution is often used in Mobile Ad Hoc Networking (MANET) ( Corson 1999). MANET...USA: IEEE Computer Society. Corson , S. 1999. Mobile Ad hoc Networking (MANET): Routing Protocol Performance Issues and Evaluation Considerations. RFC

  7. 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…

  8. Mobile free-space optical communications: a feasibility study of various battlefield scenarios

    NASA Astrophysics Data System (ADS)

    Harris, Alan; Al-Akkoumi, Mouhammad K.; Sluss, James J., Jr.

    2012-06-01

    Free Space Optics (FSO) technology was originally envisioned to be a viable solution for the provision of high bandwidth optical connectivity in the last mile of today's telecommunications infrastructure. Due to atmospheric limitations inherent to FSO technology, FSO is now widely envisioned as a solution for the provision of high bandwidth, temporary mobile communications links. The need for FSO communications links will increase as mobility is introduced to this technology. In this paper, a theoretical solution for adding mobility to FSO communication links is introduced. Three-dimensional power estimation studies are presented to represent mobile FSO transmission under various weather conditions. Three wavelengths, 0.85, 1.55 and 10 um, are tested and compared to illustrate the pros and cons of each source wavelength used for transmission, depending on prevalent weather conditions and atmospheric turbulence conditions. A simulation analysis of the transmission properties of the source wavelengths used in the study is shown.

  9. Satellite-aided land mobile communications system implementation considerations

    NASA Technical Reports Server (NTRS)

    Leroy, B. E.

    1982-01-01

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

  10. Technology assessment for communication links for mobile users in a hostile environment

    NASA Astrophysics Data System (ADS)

    Lupinetti, Francesco

    1987-03-01

    Theoretical constraints for communication links where at least one of the users is a mobile unit are developed. Additional information on communication techniques which could be used to meet the requirements of these links is made available. Possible link architecture and characteristics for short term realization are presented. Suggestion on the not yet existing hardware which should be developed in order to meet all the field requirements of a long term communication system for a mobile user in a possibly hostile environment are also made.

  11. 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

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

    PubMed

    Meder, Allison M; Wegner, Jane R

    2015-03-01

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

  13. 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

    2013-07-22

    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.

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

    PubMed

    Kuscu, Murat; Akan, Ozgur B

    2014-09-01

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

  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. TDMA-based dual-mode communication for mobile wireless sensor networks.

    PubMed

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

    2012-11-22

    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.

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

    NASA Astrophysics Data System (ADS)

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

    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. 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.

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

    NASA Astrophysics Data System (ADS)

    Orngreen, Rikke; Katre, Dinesh; Sandeep, Mulagapati

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

  20. Mobile Technology and the Challenge to Promote a Communicative City in Indonesia. Case Study Bandung Metropolitan Area

    ERIC Educational Resources Information Center

    Sutriadi, Ridwan

    2011-01-01

    The objective of this study is to assess the role of mobile technology to promote a communicative city in Indonesia. The focus is on mobile technologies as symbols of the latest information and communication technology (ICT). Communication influences the capacity building of the governmental planning employees to conduct better planning…

  1. Description and performance of a digital mobile satellite terminal

    NASA Technical Reports Server (NTRS)

    Lay, N.; Jedrey, T.; Parkyn, J.; Divsalar, D.

    1990-01-01

    A major goal of the Mobile Satellite Experiment (MSAT-X) program at the Jet Propulsion Lab (JPL) is the development of an advanced digital terminal for use in land mobile satellite communication. The terminal has been developed to minimize the risk of applying advanced technologies to future commercial mobile satellite systems (MSS). Testing with existing L band satellites was performed in fixed, land mobile and aeronautical mobile environments. JPL's development and tests of its mobile terminal have demonstrated the viability of narrowband digital voice communications in a land mobile environment through geostationary satellites. This paper provides a consolidated description of the terminal architecture and the performance of its individual elements.

  2. 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.

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

    PubMed

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

    2014-01-01

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

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

    PubMed

    Stamato, Cláudia; Moraes, Anamaria de

    2012-01-01

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

  5. Satellite-aided land mobile communications system implementation considerations

    NASA Technical Reports Server (NTRS)

    Leroy, B. E.

    1982-01-01

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

  6. Achieving Aeronautics Leadership: Aeronautics Strategic Enterprise Plan

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Today, more than ever, aggressive leadership is required to ensure that our national investments in aeronautical research, technology, and facilities are shaped into a coordinated, and high-impact, strategy. Under the auspices of the National Science and Technology Council, and in conjunction with the domestic industry, universities, the Department of Defense, and the Federal Aviation Administration - our partners in aeronautics - we propose to provide that leadership, and this document is our plan.

  7. Mobile satellite communications technology - A summary of NASA activities

    NASA Technical Reports Server (NTRS)

    Dutzi, E. J.; Knouse, G. H.

    1986-01-01

    Studies in recent years indicate that future high-capacity mobile satellite systems are viable only if certain high-risk enabling technologies are developed. Accordingly, NASA has structured an advanced technology development program aimed at efficient utilization of orbit, spectrum, and power. Over the last two years, studies have concentrated on developing concepts and identifying cost drivers and other issues associated with the major technical areas of emphasis: vehicle antennas, speech compression, bandwidth-efficient digital modems, network architecture, mobile satellite channel characterization, and selected space segment technology. The program is now entering the next phase - breadboarding, development, and field experimentation.

  8. 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.

  9. 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.

  10. SHER: A Colored Petri Net Based Random Mobility Model for Wireless Communications

    PubMed Central

    Khan, Naeem Akhtar; Ahmad, Farooq; Khan, Sher Afzal

    2015-01-01

    In wireless network research, simulation is the most imperative technique to investigate the network’s behavior and validation. Wireless networks typically consist of mobile hosts; therefore, the degree of validation is influenced by the underlying mobility model, and synthetic models are implemented in simulators because real life traces are not widely available. In wireless communications, mobility is an integral part while the key role of a mobility model is to mimic the real life traveling patterns to study. The performance of routing protocols and mobility management strategies e.g. paging, registration and handoff is highly dependent to the selected mobility model. In this paper, we devise and evaluate the Show Home and Exclusive Regions (SHER), a novel two-dimensional (2-D) Colored Petri net (CPN) based formal random mobility model, which exhibits sociological behavior of a user. The model captures hotspots where a user frequently visits and spends time. Our solution eliminates six key issues of the random mobility models, i.e., sudden stops, memoryless movements, border effect, temporal dependency of velocity, pause time dependency, and speed decay in a single model. The proposed model is able to predict the future location of a mobile user and ultimately improves the performance of wireless communication networks. The model follows a uniform nodal distribution and is a mini simulator, which exhibits interesting mobility patterns. The model is also helpful to those who are not familiar with the formal modeling, and users can extract meaningful information with a single mouse-click. It is noteworthy that capturing dynamic mobility patterns through CPN is the most challenging and virulent activity of the presented research. Statistical and reachability analysis techniques are presented to elucidate and validate the performance of our proposed mobility model. The state space methods allow us to algorithmically derive the system behavior and rectify the

  11. SHER: a colored petri net based random mobility model for wireless communications.

    PubMed

    Khan, Naeem Akhtar; Ahmad, Farooq; Khan, Sher Afzal

    2015-01-01

    In wireless network research, simulation is the most imperative technique to investigate the network's behavior and validation. Wireless networks typically consist of mobile hosts; therefore, the degree of validation is influenced by the underlying mobility model, and synthetic models are implemented in simulators because real life traces are not widely available. In wireless communications, mobility is an integral part while the key role of a mobility model is to mimic the real life traveling patterns to study. The performance of routing protocols and mobility management strategies e.g. paging, registration and handoff is highly dependent to the selected mobility model. In this paper, we devise and evaluate the Show Home and Exclusive Regions (SHER), a novel two-dimensional (2-D) Colored Petri net (CPN) based formal random mobility model, which exhibits sociological behavior of a user. The model captures hotspots where a user frequently visits and spends time. Our solution eliminates six key issues of the random mobility models, i.e., sudden stops, memoryless movements, border effect, temporal dependency of velocity, pause time dependency, and speed decay in a single model. The proposed model is able to predict the future location of a mobile user and ultimately improves the performance of wireless communication networks. The model follows a uniform nodal distribution and is a mini simulator, which exhibits interesting mobility patterns. The model is also helpful to those who are not familiar with the formal modeling, and users can extract meaningful information with a single mouse-click. It is noteworthy that capturing dynamic mobility patterns through CPN is the most challenging and virulent activity of the presented research. Statistical and reachability analysis techniques are presented to elucidate and validate the performance of our proposed mobility model. The state space methods allow us to algorithmically derive the system behavior and rectify the errors

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

    ERIC Educational Resources Information Center

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

    2015-01-01

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

  13. Western Aeronautical Test Range

    NASA Technical Reports Server (NTRS)

    Sakahara, Robert D.

    2008-01-01

    This viewgraph presentation reviews the work of the Western Aeronautical Test Range (WATR). NASA's Western Aeronautical Test Range is a network of facilities used to support aeronautical research, science missions, exploration system concepts, and space operations. The WATR resides at NASA's Dryden Flight Research Center located at Edwards Air Force Base, California. The WATR is a part of NASA's Corporate Management of Aeronautical Facilities and funded by the Strategic Capability Asset Program (SCAP). Maps show the general location of the WATR area that is used for aeronautical testing and evaluation. The products, services and facilities of WATR are discussed,

  14. The future role of satellite communications in an improved air traffic management

    NASA Astrophysics Data System (ADS)

    Gauthier, Patrice

    1992-07-01

    The need for air to ground communication in Air Traffic Control (ATC) is discussed and a summary on the birth of aeronautical satellite communication is given. The standardization of an aeronautical mobile communications service by the International Civil Aviation Organization is reported. The feasibility analysis of satellite communications for ATC carried out by the French civil aviation is described. This 'South Pacific Trial' is regarded as a first step towards a full operational implementation.

  15. Analysis of the grounding system for a mobile communication site placed on HV power line mast

    NASA Astrophysics Data System (ADS)

    Bîrsan, I.; Munteanu, C.; Horgoș, M.; Ilut, T.

    2016-08-01

    This paper aims to analyze the potential distribution on the soil surface or potential variation on the main directions inside computing mobile site. I want to study a system made the earth a mobile communications site, antennas operator and the system of which the earth is placed on a High Voltage Power Line Mast (LEA 110 KV). I made direct measurements and I use a 3D software for analyze the results and simulating some possible solutions.

  16. Leveraging mobile smart devices to improve interprofessional communications in inpatient practice setting: A literature review.

    PubMed

    Aungst, Timothy Dy; Belliveau, Paul

    2015-01-01

    As mobile smart device use has increased in society, the healthcare community has begun using these devices for communication among professionals in practice settings. The purpose of this review is to describe primary literature which reports on the experiences with interprofessional healthcare communication via mobile smart devices. Based on these findings, this review also addresses how these devices may be utilized to facilitate interprofessional education (IPE) in health professions education programs. The literature search revealed limited assessments of mobile smart device use in clinical practice settings. In available reports, communication with mobile smart devices was perceived as more effective and faster among interdisciplinary members. Notable drawbacks included discrepancies in the urgency labeling of messages, increased interruptions associated with constant accessibility to team members, and professionalism breakdowns. Recently developed interprofessional competencies include an emphasis on ensuring that health profession students can effectively communicate on interprofessional teams. With the increasing reliance on mobile smart devices in the absence of robust benefit and risk assessments on their use in clinical practice settings, use of these devices may be leveraged to facilitate IPE activities in health education professions programs while simultaneously educating students on their proper use in patient care settings.

  17. [Psychophysiological indicators for children using mobile phones. Communication 2. Results of four-year monitoring].

    PubMed

    Khorseva, N I; Grigor'ev, Iu G; Gorbunova, N V

    2011-01-01

    This study submits the results of a four-year monitoring of a complex diagnostics of the psychophysiological indicators for 196 children aged 7 to 12 years old: 147 of them are child users of mobile communication (test group) and 49 are in the control group. We have identified the following major trends of the psychophysiological indicators for child users of mobile communication: an increased number of phonemic perception disorders, abatement of efficiency, reduced indicators for the arbitrary and semantic memory, an increased fatigue. A steady decline of the parameters from high values to bottom standards has been found.

  18. High-Speed Mobile Communications in Hostile Environments

    NASA Astrophysics Data System (ADS)

    Agosta, S.; Sierra, R.; Chapron, F.

    2015-12-01

    With the inexorable increase in the use of mobile devices, wireless connectivity is expected by users anywhere, anytime. In general, this requirement is addressed in office buildings or public locations through the use of Wi-Fi technology but Wi-Fi is not well adapted for use in large experiment halls and complex underground environments, especially those where radiation exposure is an issue, such as the LHC tunnel and experimental caverns. 4G/LTE technology, however, looks to be well adapted to addressing mobility needs in such areas. We report here the studies CERN has undertaken on the use of 4G/LTE in the LHC tunnel, presenting results on the data throughput that can be achieved and discussing issues such as the provision of a consistent user experience.

  19. Lightweight, mobile E-mail for intra-clinic communication.

    PubMed Central

    Acuff, R. D.; Fagan, L. M.; Rindfleisch, T. C.; Levitt, B. J.; Ford, P. M.

    1997-01-01

    We have developed a mobile messaging system designed for use in the clinic setting. The system is designed to facilitate quick, informal, interactions that occur in a clinical setting, e.g., requests for assistance or information. The system includes safeguards to make sure that the sender of a message is aware if a message is not read in a timely fashion. Evaluation of the system shows message delivery was about 50% slower than our target of 30 seconds. Although the mobile device used is fairly small when combined with a radio unit, it is too bulky and users did not necessarily carry the system with them. This led to delays (over eleven minutes on average) before messages were seen. We expect that improvements in hardware and clinical software will lead to more common use of such adjunct software systems. PMID:9357721

  20. Modeling the Transformational Communications System Urban Land Mobile Satellite Channel

    DTIC Science & Technology

    2007-12-01

    solution. Instead, Baum, Petrie and others derived a specific version of the Expectation- Maximization algorithm to solve the problem iteratively. A...is expected to be a platoon of HMMWVs, perhaps on a combat or peacekeeping mission. A mobile ad-hoc network is defined as: a self-configuring...3] Ben Iannotta, “Playing if Safe; TSAT puts a premium on tried-and-tested technologies.” C4ISR The Journal of Net -centric Warfare, vol. 6, no

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

    PubMed

    Morvai, Júlia; Szabó, Rita

    2015-05-17

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

  2. "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…

  3. 76 FR 32360 - Information Collection Being Reviewed by the Federal Communications Commission

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-06

    ...: Part 27--Miscellaneous Wireless Communications Services in the 2.3 GHz Band. Form No.: N/A. Type of... Service (SDARS), Aeronautical Mobile Telemetry (AMT), and Deep Space Network (DSN) operations in...

  4. Assessing reliable human mobility patterns from higher order memory in mobile communications.

    PubMed

    Matamalas, Joan T; De Domenico, Manlio; Arenas, Alex

    2016-08-01

    Understanding how people move within a geographical area, e.g. a city, a country or the whole world, is fundamental in several applications, from predicting the spatio-temporal evolution of an epidemic to inferring migration patterns. Mobile phone records provide an excellent proxy of human mobility, showing that movements exhibit a high level of memory. However, the precise role of memory in widely adopted proxies of mobility, as mobile phone records, is unknown. Here we use 560 million call detail records from Senegal to show that standard Markovian approaches, including higher order ones, fail in capturing real mobility patterns and introduce spurious movements never observed in reality. We introduce an adaptive memory-driven approach to overcome such issues. At variance with Markovian models, it is able to realistically model conditional waiting times, i.e. the probability to stay in a specific area depending on individuals' historical movements. Our results demonstrate that in standard mobility models the individuals tend to diffuse faster than observed in reality, whereas the predictions of the adaptive memory approach significantly agree with observations. We show that, as a consequence, the incidence and the geographical spread of a disease could be inadequately estimated when standard approaches are used, with crucial implications on resources deployment and policy-making during an epidemic outbreak.

  5. 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.

  6. [Problems of harmonization of sanitary regulations of the electromagnetic fields of mobile radio communication equipment].

    PubMed

    Pal'tsev, Iu P; Pokhodzeĭ, L V; Rubtsova, N B; Bogacheva, E V

    2013-01-01

    In the article there are presented data on the probable adverse effects of electromagnetic fields generated by means of mobile cellulary radio communication equipment, a comparative analysis of hygienic rating and methods of measurement of their parameters in Russia and abroad has been performed, and the ways of harmonizing hygienic rules have been outlined, the necessity of further research to risk assessment of the use of cellular radio communication devices by population and preventive measures have been substantiated.

  7. Acoustic Communications and Navigation for Mobile Under-Ice Sensors

    DTIC Science & Technology

    2014-09-30

    urethane-filled hose with spiral conductors for the through- ice transition where a cable would be vulnerable. The buoy is designed to float after melting ...project is that it allows a drifting, ice -tethered navigation and communications system to be employed in the Arctic during times when it is not possible...performing tactical missions under Arctic ice . Potential programs for transition include LD-UUV if an Arctic version is fielded in the future. RELATED

  8. An adaptive array antenna for mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Milne, Robert

    1990-01-01

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

  9. Satellites for Mobile Communications - Civilian and Defense Applications.

    DTIC Science & Technology

    1984-01-01

    Advances in both satellite and terminal technologies have made larger, more powerful satellites and smaller, portab e earth terminals possible. This...primarily been used to provide fixed communications. Advances in both satellite and terminal technologies have made larger, more powerful satellites and...INTRODUCTION Satellite technology has improved signifi- cantly since the Soviet Union launched Sputnik in 1957. The "race for space" was on. Advances in

  10. 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.

  11. Nomenclature for Aeronautics

    NASA Technical Reports Server (NTRS)

    1927-01-01

    This nomenclature for aeronautics was prepared by a Special Conference on Aeronautical Nomenclature by the executive committee of the National Advisory Committee for Aeronautics at a meeting held on August 19, 1924, at which meeting Dr. Joseph S. Ames was appointed chairman of the conference. The conference was composed of representatives of the National Advisory Committee for Aeronautics and specially appointed representatives officially designated by the Army Air Service, the Bureau of Aeronautics of the Navy Department, the Bureau of Standards, the American Society of Mechanical Engineers, the Society of Automotive Engineers, and the Aeronautical Chamber of Commerce. The purpose of the committee in the preparation and publication of this report is to secure uniformity in the official documents of the government and, as far as possible, in technical and other commercial publications

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

    SciTech Connect

    Olama, Mohammed M; Djouadi, Seddik M; Charalambous, Prof. Charalambos

    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.

  13. 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.

  14. NASA thesaurus aeronautics vocabulary

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The controlled vocabulary used by the NASA Scientific and Technical Information effort to index documents in the area of aeronautics is presented. The terms comprise a subset of the 1988 edition of the NASA Thesaurus and its supplements issued through the end of 1990. The Aeronautics Vocabulary contains over 4700 terms presented in a hierarchical display format. In addition to aeronautics per se, the vocabulary covers supporting terminology from areas such as fluid dynamics, propulsion engineering, and test facilities and instrumentation.

  15. Nomenclature for Aeronautics

    NASA Technical Reports Server (NTRS)

    1923-01-01

    This nomenclature for aeronautics was prepared by a special conference on aeronautical nomenclature, composed of representatives of the Army and Navy Air Services, the Air Mail Service, the Bureau of Standards, the National Advisory Committee for Aeronautics, and private life. This report supersedes all previous publications of the committee on this subject. It is published with the intention of securing greater uniformity and accuracy in official documents of the government, and, as far as possible, in technical and other commercial publications. (author)

  16. Nomenclature for Aeronautics

    NASA Technical Reports Server (NTRS)

    1924-01-01

    This nomenclature for aeronautics was prepared by a special conference on aeronautical nomenclature by the Executive Committee of the National Advisory Committee for Aeronautics at a meeting held August 11, 1933. This publication supersedes all previous publications of the committee on this subject. The purpose of the committee in the preparation and publication of this report is to secure uniformity in the official documents of the government and, as far as possible, in technical and other commercial publications.

  17. 75 FR 32984 - Policy on the Retention of Supporting Documents and the Use of Electronic Mobile Communication...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-10

    ... which the motor carrier can produce electronic mobile communication/tracking records acceptable under... available under this Policy, the motor carrier must show that the electronic mobile communication/tracking.../tracking technology, is not required to be maintained as a supporting document under 49 CFR Part...

  18. 75 FR 8399 - In the Matter of Certain Mobile Communications and Computer Devices and Components Thereof...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-24

    ... COMMISSION In the Matter of Certain Mobile Communications and Computer Devices and Components Thereof; Notice... U.S.C. 1337, on behalf of Apple Inc., f/k/a Apple Computer, Inc. of Cupertino, California. The... computer devices and components thereof by reason of infringement of certain claims of U.S. Patent Nos....

  19. 75 FR 6704 - In the Matter of Certain Mobile Telephones and Wireless Communication Devices Featuring Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

    ... COMMISSION In the Matter of Certain Mobile Telephones and Wireless Communication Devices Featuring Digital... Terminate the Investigation With Respect to Respondents Samsung Electronics Co., Ltd., Samsung Electronics... to terminate the above-captioned investigation with respect to Samsung Electronics Co., Ltd.,...

  20. 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…

  1. [Ecological aspects of electromagnetic radiation emitted by mobile stations of communication means].

    PubMed

    Buzov, A L; Kol'chugin, Iu I; Pal'tsev, Iu P

    1996-01-01

    Electromagnetic environment of staffers using mobile communication means is characterized by complicated field structure with prevalent magnetic load. Biologic effects of the field parameters depend to large extent on location of emitting source and exposed object, presence of reflecting articles and grounding in the neighborhood. Human body is sensitive to electromagnetic influence on the certain organs.

  2. Faculty Use and Perception of Mobile Information and Communication Technology (m-ICT) for Teaching Practices

    ERIC Educational Resources Information Center

    Biddix, J. Patrick; Chung, Chung Joo; Park, Han Woo

    2016-01-01

    The purpose of this study was to consider faculty use and perception of mobile information and communication technology (m-ICT) for teaching practices. The researchers examined qualitative responses about specific m-ICT use and efficiency amongst Korean and US faculty (n = 59) at three different institutions. Findings from multi-level textual…

  3. 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.

  4. A Knowledge Based System for the Design of Mobile Subscriber Equipment Communications Networks.

    DTIC Science & Technology

    1985-12-01

    organic chemistry , and medical diagnosis (20:5-6). Expert systems are generally composed of three parts: a database containing the specialized domain...Pennsylvania, 26 March 1984. 31. Schaum , Don and others. "MSE: Mobile Subscriber Equipment," Army Communicator, 9: 6-22 (Fall 1984). 32. Schneider, G

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

    NASA Astrophysics Data System (ADS)

    Görbil, Gökçe; Gelenbe, Erol

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

  6. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1978-01-01

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

  8. 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.

  9. Future mobile satellite communication concepts at 20/30 GHz

    NASA Astrophysics Data System (ADS)

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

    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.

  10. 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.

  11. Developing a global aeronautical satellite system

    NASA Technical Reports Server (NTRS)

    Dement, Donald K.

    1988-01-01

    Arinc, an airline industry-owned and operated company in the United States, has taken steps toward establishing a global aeronautical satellite communications system. Plans call for initiation of a thin-route data operation in 1989, upgrading to establish voice communications via shared spot-beam transponders carried on other satellites, and deploying a worldwide network using dedicated satellites by 1994.

  12. Research and development project and experimental equipment for SHF land mobile communications

    NASA Astrophysics Data System (ADS)

    Mizuno, Mitsuhiko

    1995-09-01

    Research on the application of 3 to 10 GHz band to microcellular and indoor communications have been started in the CRL. The tentative target frequencies are 3.3 GHz, 5.2 GHz, and 8.4 GHz. These bands will make it possible to provide wider-band communication services such as multimedia services, while voice communication services will be provided in UHF bands in the PCS or PCN systems. This multimedia concept is close to that of mobile computing. It will also be possible to be used as a mobile terminal for ISDN. For the first stage, we are now conducting a propagation study in this band, and data transmission and wireless access studies will follow it. These study plans and measuring equipment are described.

  13. Nomenclature for aeronautics

    NASA Technical Reports Server (NTRS)

    1920-01-01

    Report defines the principal terms which have come into use in the development of aeronautics. It was prepared in cooperation with a committee engaged upon a similar undertaking in Great Britain. As a result this nomenclature is in substantial agreement with the one which has been adopted by the aeronautical authorities of Great Britain.

  14. Bibliography of Aeronautics: 1926

    NASA Technical Reports Server (NTRS)

    Brockett, Paul

    1928-01-01

    This Bibliography of Aeronautics for 1926 covers the aeronautical literature published from January 1 to December 31, 1926. The first Bibliography of Aeronautics was published by the Smithsonian Institution as volume 55 of the Smithsonian Miscellaneous Collections and covered the material published prior to June 30, 1909. Supplementary volumes of the Bibliography of Aeronautics for the subsequent years have been published by the National Advisory Committee for Aeronautics. The last preceding volume was for the calendar year 1925. As in the previous volumes, citations of the publications of all nations are included in the languages in which these publications originally appeared. The arrangement is dictionary form with author find subject entry, and one alphabetical arrangement. Detail in the matter of subject reference has been omitted on aCC01.mt of the cost of presentation, but an attempt has been made to give sufficient cross reference for research in special lines.

  15. Bibliography of Aeronautics: 1932

    NASA Technical Reports Server (NTRS)

    1935-01-01

    This Bibliography of Aeronautics for 1932 covers the aeronautical literature published from January 1 to December 31, 1932. The first Bibliography of Aeronautics was published by the Smithsonian Institution as volume 55 of the Smithsonian Miscellaneous Collections and covered the material published prior to June 30, 1909. Supplementary volumes of the Bibliography of Aeronautics for the subsequent years have been published by the National Advisory Committee for Aeronautics. The last preceding volume was for the calendar year 1931. As in the previous volumes, citations of the publications of all nations are included in the languages in which these publications originally appeared. The arrangement is in dictionary form with author and subject entry and one alphabetical arrangement. Detail in the matter of subject reference has been omitted on account of the cost of presentation, but an attempt has been made to give sufficient cross-reference for research in special lines.

  16. Bibliography of Aeronautics: 1928

    NASA Technical Reports Server (NTRS)

    Brockett, Paul

    1928-01-01

    This Bibliography of Aeronautics for 1928 covers the aeronautical literature published from January 1 to December 31, 1928. The first Bibliography of Aeronautics was published by the Smithsonian Institution as volume 55 of the Smithsonian Miscellaneous Collections and covered the material published prior to June 30, 1909. Supplementary volumes of the Bibliography of Aeronautics for the subsequent years have been published by the National Advisory Committee for Aeronautics. The last preceding volume was for the calendar year 1927. As in the previous volumes, citations of the publications of all nations are included in the languages in which these publications originally appeared. The arrangement is in dictionary form with author and subject entry, and one alphabetical arrangement. Detail in the matter of subject reference has been omitted on account of the cost of presentation, but an attempt has been made to give sufficient cross reference for research in special lines.

  17. Bibliography of Aeronautics, 1929

    NASA Technical Reports Server (NTRS)

    Brockett, Paul

    1930-01-01

    This Bibliography of Aeronautics for 1929 covers the aeronautical literature published from January 1 to December 31, 1929. The first Bibliography of Aeronautics was published by the Smithsonian Institution as Volume 55 of the Smithsonian Miscellaneous Collections and covered the material published prior to June 30, 1909. Supplementary volumes of the Bibliography of Aeronautics for the subsequent years have been published by the National Advisory Committee for Aeronautics. The last preceding volume was for the calendar year 1928. As in the previous volumes, citations of the pUblications of all nations are included in th.e languages in which. these publications originally appeared. The arrangement is in dictionary form with author and subject entry, and one alphabetical arrangement. Detail in the matter of subject reference has been omitted on account of the cost of presentation, but an attempt has been made to give sufficient cross reference for research in special lines.

  18. 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.

  19. 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

  20. [NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 2:] Technical communications in aeronautics: Results of an exploratory study. An analysis of managers' and nonmanagers' responses

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Glassman, Myron; Barclay, Rebecca O.; Oliu, Walter E.

    1989-01-01

    Data collected from an exploratory study concerned with the technical communications practices of aerospace engineers and scientists were analyzed to test the primary assumption that aerospace managers and nonmanagers have different technical communications practices. Five assumptions were established for the analysis. Aerospace managers and nonmanagers were found to have different technical communications practices for three of the five assumptions tested. Although aerospace managers and nonmanagers were found to have different technical communications practices, the evidence was neither conclusive nor compelling that the presumption of difference in practices could be attributed to the duties performed by aerospace managers and nonmanagers.

  1. [NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 3:] Technical communications in aeronautics: Results of an exploratory study. An analysis of profit managers' and nonprofit managers' responses

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Glassman, Myron; Barclay, Rebecca O.; Oliu, Walter E.

    1989-01-01

    Data collected from an exploratory study concerned with the technical communications practices of aerospace engineers and scientists were analyzed to test the primary assumption that profit and nonprofit managers in the aerospace community have different technical communications practices. Five assumptions were established for the analysis. Profit and nonprofit managers in the aerospace community were found to have different technical communications practices for one of the five assumptions tested. It was, therefore, concluded that profit and nonprofit managers in the aerospace community do not have different technical communications practices.

  2. Aeronautics and space report of the President

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This report describes the activities and accomplishments of all agencies of the United States in the fields of aeronautics and space science during FY 1994. Activity summaries are presented for the following areas: space launch activities, space science, space flight and space technology, space communications, aeronuatics, and studies of the planet Earth. Several appendices providing data on U.S. launch activities, the Federal budget for space and aeronautics, remote sensing capabilities, and space policy are included.

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

    PubMed

    Johnson, William

    2005-01-01

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

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

    PubMed

    Pereira, Carlos; Aguiar, Ana

    2014-10-20

    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.

  5. 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

  6. Nomenclature for Aeronautics

    NASA Technical Reports Server (NTRS)

    1939-01-01

    The nomenclature for aeronautics presented in this Report No. 474 is a revision of the last previous report on this subject (i.e., Report no. 240.) This report is published for the purpose of encouraging greater uniformity and precision in the use of terms relating to aeronautics, both in official documents of the Government and in commercial publications. Terms in general use in other branches of engineering have been included only where they have some special significance in aeronautics, or form an integral part of its terminology.

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

    PubMed

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

    2008-01-01

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

  8. 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.

  9. Curriculum for modern aeronautics

    NASA Technical Reports Server (NTRS)

    Roberts, L.

    1975-01-01

    Methods for improving the university training of aeronautical engineering students are discussed. Specific topics considered are: (1) the kind of students which should be developed through aeronautical engineering education, (2) to what extent should aerospace engineering be prepared for diversity and change, (3) to what extent should theory be emphasized as compared with practical engineering and design, and (4) a suggestion for NASA/Industry/University collaboration.

  10. A Mobile Communications Space Link Between the Space Shuttle Orbiter and the Advanced Communications Technology Satellite

    NASA Technical Reports Server (NTRS)

    Fink, Patrick; Arndt, G. D.; Bondyopadhyay, P.; Shaw, Roland

    1994-01-01

    A communications experiment is described as a link between the Space Shuttle Orbiter (SSO) and the Advanced Communications Technology Satellite (ACTS). Breadboarding for this experiment has led to two items with potential for commercial application: a 1-Watt Ka-band amplifier and a Ka-band, circularly polarized microstrip antenna. Results of the hybrid Ka-band amplifier show gain at 30 dB and a saturated output power of 28.5 dBm. A second version comprised of MMIC amplifiers is discussed. Test results of the microstrip antenna subarray show a gain of approximately 13 dB and excellent circular polarization.

  11. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2007-12-01

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

  13. 76 FR 30154 - Maritime Communications/Land Mobile, LLC, Licensee of Various Authorizations in the Wireless...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-24

    ...This document commences a hearing proceeding to determine ultimately whether Maritime Communications/Land Mobile, LLC (Maritime) is qualified to be and to remain a Commission licensee, and as a consequence whether any or all of its licenses should be revoked, and whether any or all of the applications to which Maritime is a party should be denied. The issues designated for hearing also include......

  14. Choice of FDMA/SCPC access technique for aeronautical satellite voice system

    NASA Technical Reports Server (NTRS)

    Smith, G. K.

    1989-01-01

    A worldwide aeronautical mobile satellite system is about to become operational. The system architecture and access methods have been debated extensively, resulting in the selection of Time Division Multiplexing/Time Division Multiple Access (TDM/TDMA) access for packet data, and Single Channel Per Carrier (SCPC) for voice. These have become standards for airline use, and also satisfy the known requirements of ICAO for safety related communications. Voice communications are expected to absorb a high proportion of satellite bandwidth and power in the future. Here, it is explained why INMARSAT selected Frequency Division Multiple Access/SCPC satellite access for this application.

  15. 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.

  16. Estimate of Interference from the Aeronautical Mobile Services of the Cities of Glendale and Pasadena to Goldstone Radio Astronomy Stations at 4.9 Gigahertz

    NASA Astrophysics Data System (ADS)

    Ho, C.; Sue, M.; Manshadi, F.

    2006-05-01

    The Federal Communications Commission (FCC) recently allocated the 4.9-GHz band to public safety telecommunications services. Radio Astronomy Services (RAS) also has been using this frequency. NASA will primarily use Deep Space Station 28 (DSS 28) at Goldstone, California, for radio astronomy services that are sensitive to radio-frequency interference (RFI). This study is to determine the RFI potential of airborne transmission from two cities to radio astronomy sites in Goldstone. Propagation losses over the terrain between both cities and Goldstone are estimated using the Trans-Horizon Interference Propagation Loss (THIPL) software recently developed at JPL and high-resolution terrain data. The necessary coordination area for protecting the Goldstone radio astronomy station has been defined based on the minimum propagation loss required. Study results and suggestions for modification to the airborne areas proposed by both cities' police departments are presented.

  17. Review of mobile communication devices as potential reservoirs of nosocomial pathogens.

    PubMed

    Brady, R R W; Verran, J; Damani, N N; Gibb, A P

    2009-04-01

    Innovation in mobile communication technology has provided novel approaches to the delivery of healthcare and improvements in the speed and quality of routine medical communication. Bacterial contamination of mobile communication devices (MCDs) could be an important issue affecting the implementation of effective infection control measures and might have an impact on efforts to reduce cross-contamination. This review examines recent studies reporting bacterial contamination of MCDs, most demonstrating that 9-25% of MCDs are contaminated with pathogenic bacteria. We examine previously investigated risk factors for MCD contamination in addition to work on surface decontamination of the device. Recommendations to reduce contamination risks include staff education, strict hand hygiene measures, guidelines on device cleaning and consideration of the restrictions regarding use of mobile phone technology in certain high risk areas, for example, operating theatres, intensive care units and burns units. Further work is required to evaluate the benefit of such interventions on MCD contamination and to determine whether a link exists between contamination and subsequent patient infection.

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

    NASA Astrophysics Data System (ADS)

    Kollár, Martin

    2012-05-01

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

  1. Communicating textual health information to the mobile phones of visually-impaired users.

    PubMed

    Kummervold, Per Egil; Holthe, Halgeir

    2008-01-01

    We investigated how short messages communicating health information would best be distributed to people with vision difficulties using mobile phones. Twelve visually-impaired persons who were unable to read short message service (SMS) messages directly compared three methods of presenting text messages as speech: (1) ordinary SMS messages were sent to the users and converted into speech by the mobile phone; (2) multimedia messages were sent to the users with prerecorded speech-synthesized information; and (3) mobile phone calls were placed to the users and prerecorded speech-synthesized messages were streamed to them. The latter two approaches used server-generated sound files. Over a three-month trial period, we sent a total of 88 SMS messages to the subjects, 111 multimedia messaging service (MMS) messages and 104 telephone calls. All of the SMS messages, 88% of the MMS messages and 69% of the telephone calls were received. In subsequent interviews, we asked the users which presentation method they preferred. SMS scored significantly better than both MMS (P = 0.033) and telephones (P = 0.006). All three methods had serious drawbacks. However, the study suggests that it might be possible to develop suitable technology for communicating with people with vision difficulties by mobile phone.

  2. Investigating the Impact of Personality Factors on Perceived Communication Mobility of Non-Native English Speaking Thai Professionals in International Companies

    ERIC Educational Resources Information Center

    Marina, Olga A.; Rajprasit, Krich

    2014-01-01

    Communication mobility has been suggested as an element of the complex construct of professional communicative competence, with a shared core of English in the oral mode, for professional international communication. This study aims (1) to investigate the possible correlation between the perceived level of communication mobility, and the influence…

  3. Mobile and traditional modes of communication among male Latino farmworkers: Implications for health communication and dissemination

    PubMed Central

    Sandberg, Joanne C.; Spears Johnson, Chaya R.; Nguyen, Ha T.; Talton, Jennifer W.; Quandt, Sara A.; Chen, Haiying; Summers, Phillip; Arcury, Thomas A.

    2016-01-01

    Objectives This analysis describes 1) cell phone and smartphone ownership, 2) continuity of phone numbers, 3) use of specific technologies while inside and outside the U.S., and 4) perceived adequacy of specific formats to receive health research results among Latino farmworkers. Methods Telecommunications questionnaires were administered to 165 and 102 farmworkers in North Carolina in 2012 and 2013, respectively. Univariate and bivariate analyses were completed. Results Increasing numbers of Latino farmworkers own cell phones and smartphones. Talk and text functions are used frequently. Relatively few farmworkers maintain consistent phone numbers. They prefer to receive study results through low technology formats. Conclusion Strategies to use cell phones to improve health or to share research findings will face obstacles in this population. Public health officials who identify and implement effective strategies to overcome these barriers may be able to harness mobile technologies to address the needs of Latino farmworkers. PMID:26463228

  4. Diaphragms for Aeronautic Instruments

    NASA Technical Reports Server (NTRS)

    Hersey, M D

    1924-01-01

    This investigation was carried out at the request of the National Advisory Committee for Aeronautics and comprises an outline of historical developments and theoretical principles, together with a discussion of expedients for making the most effective use of existing diaphragms actuated by the hydrostatic pressure form an essential element of a great variety instruments for aeronautic and other technical purposes. The various physical data needed as a foundation for rational methods of diaphragm design have not, however, been available hitherto except in the most fragmentary form.

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

    PubMed

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

    2003-01-01

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

  6. Cyber Technology for Materials and Structures in Aeronautics and Aerospace

    NASA Technical Reports Server (NTRS)

    Pipes, R. Byron

    2002-01-01

    The evolution of composites applications in aeronautics from 1970 to the present is discussed. The barriers and challenges to economic application and to certification are presented and recommendations for accelerated development are outlined. The potential benefits of emerging technologies to aeronautics and their foundation in composite materials are described and the resulting benefits in vehicle take off gross weight are quantified. Finally, a 21st century vision for aeronautics in which human mobility is increased by an order of magnitude is articulated.

  7. The history of aeronautical medicine in Venezuela

    NASA Technical Reports Server (NTRS)

    Iriarte, D. R.

    1986-01-01

    The Aerial Medical Service of the Ministry of Transportation and Communications of Venezuela was created on June 1949, and later became the Department of Aeronautical Medicine. Its functions include the medical examinations of future pilots, navigators and flight engineers. The importance of good mental and physical health in all flight and ground personnel to ensure the safety of air travel is discussed.

  8. University research in aeronautics

    NASA Technical Reports Server (NTRS)

    Duberg, J. E.

    1975-01-01

    The contributions which universities can make to aeronautical research projects are discussed. The activities of several facilities are presented to show the effectiveness of the educational and research programs. Reference is made to the Intergovernmental Personnel Act of 1970 which permits an exchange of federal agency personnel with state and local governments and with public and private higher education schools.

  9. Aeronautical facilities assessment

    NASA Technical Reports Server (NTRS)

    Penaranda, F. E. (Compiler)

    1985-01-01

    A survey of the free world's aeronautical facilities was undertaken and an evaluation made on where the relative strengths and weaknesses exist. Special emphasis is given to NASA's own capabilities and needs. The types of facilities surveyed are: Wind Tunnels; Airbreathing Propulsion Facilities; and Flight Simulators

  10. ARMD Fundamental Aeronautics Program

    NASA Technical Reports Server (NTRS)

    Dryer, Jay; DelRosario, Ruben

    2010-01-01

    This slide presentation focuses work of the Aeronautics Research Mission Directorate (ARMD) with particular interest on the work being done to address the environmental and energy efficiency challenges. Particular interest is on the Subsonic Fixed Wing (SFW) project, though there is discussion of the rotorcraft and the supersonics environmental challenges.

  11. Visible light communication using mobile-phone camera with data rate higher than frame rate.

    PubMed

    Chow, Chi-Wai; Chen, Chung-Yen; Chen, Shih-Hao

    2015-10-05

    Complementary Metal-Oxide-Semiconductor (CMOS) image sensors are widely used in mobile-phone and cameras. Hence, it is attractive if these image sensors can be used as the visible light communication (VLC) receivers (Rxs). However, using these CMOS image sensors are challenging. In this work, we propose and demonstrate a VLC link using mobile-phone camera with data rate higher than frame rate of the CMOS image sensor. We first discuss and analyze the features of using CMOS image sensor as VLC Rx, including the rolling shutter effect, overlapping of exposure time of each row of pixels, frame-to-frame processing time gap, and also the image sensor "blooming" effect. Then, we describe the procedure of synchronization and demodulation. This includes file format conversion, grayscale conversion, column matrix selection avoiding blooming, polynomial fitting for threshold location. Finally, the evaluation of bit-error-rate (BER) is performed satisfying the forward error correction (FEC) limit.

  12. Mobile phone-based biosensing: An emerging "diagnostic and communication" technology.

    PubMed

    Quesada-González, Daniel; Merkoçi, Arben

    2017-06-15

    In this review we discuss recent developments on the use of mobile phones and similar devices for biosensing applications in which diagnostics and communications are coupled. Owing to the capabilities of mobile phones (their cameras, connectivity, portability, etc.) and to advances in biosensing, the coupling of these two technologies is enabling portable and user-friendly analytical devices. Any user can now perform quick, robust and easy (bio)assays anywhere and at any time. Among the most widely reported of such devices are paper-based platforms. Herein we provide an overview of a broad range of biosensing possibilities, from optical to electrochemical measurements; explore the various reported designs for adapters; and consider future opportunities for this technology in fields such as health diagnostics, safety & security, and environment monitoring.

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

    NASA Technical Reports Server (NTRS)

    Paul, Lori (Editor)

    1991-01-01

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

  14. Performance of a low data rate speech codec for land-mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Gersho, Allen; Jedrey, Thomas C.

    1990-01-01

    In an effort to foster the development of new technologies for the emerging land mobile satellite communications services, JPL funded two development contracts in 1984: one to the Univ. of Calif., Santa Barbara and the other to the Georgia Inst. of Technology, to develop algorithms and real time hardware for near toll quality speech compression at 4800 bits per second. Both universities have developed and delivered speech codecs to JPL, and the UCSB codec was extensively tested by JPL in a variety of experimental setups. The basic UCSB speech codec algorithms and the test results of the various experiments performed with this codec are presented.

  15. Advanced communication satellites worldwide - Satellites of opportunity for the ACTS mobile terminal

    NASA Technical Reports Server (NTRS)

    Girardey, Catherine C.

    1993-01-01

    Space agencies worldwide are involved in advanced satellite communication systems. This paper presents an overview of these satellites and related technologies in the U.S., Europe, and Japan. They are geostationary satellites using high frequency bands such as K/Ka (20/30 GHz) and O-band (millimeter wave), as well as optical frequencies. The similarity of these programs demonstrate a common interest to develop large capacity satellite communication systems, and shows that closer international cooperation could be set up. The ACTS Mobile Terminal (AMT) project discussed here is such an example. The AMT's compatibility with satellites other than ACTS has been studied, and a proposed common experiment is presented here. The Japanese Engineering Test Satellite ETS-VI has been identified as the best initial 'satellite of opportunity' for AMT in this preliminary assessment.

  16. Using a communication model to collect measurement data through mobile devices.

    PubMed

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

    2012-01-01

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

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

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

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

    PubMed Central

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

    2012-01-01

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

  19. Robust formation tracking control of mobile robots via one-to-one time-varying communication

    NASA Astrophysics Data System (ADS)

    Dasdemir, Janset; Loría, Antonio

    2014-09-01

    We solve the formation tracking control problem for mobile robots via linear control, under the assumption that each agent communicates only with one 'leader' robot and with one follower, hence forming a spanning-tree topology. We assume that the communication may be interrupted on intervals of time. As in the classical tracking control problem for non-holonomic systems, the swarm is driven by a fictitious robot which moves about freely and which is a leader to one robot only. Our control approach is decentralised and the control laws are linear with time-varying gains; in particular, this accounts for the case when position measurements may be lost over intervals of time. For both velocity-controlled and force-controlled systems, we establish uniform global exponential stability, hence consensus formation tracking, for the error system under a condition of persistency of excitation on the reference angular velocity of the virtual leader and on the control gains.

  20. Interprofessional Communication of Clinicians Using a Mobile Phone App: A Randomized Crossover Trial Using Simulated Patients

    PubMed Central

    Johnston, Maximilian; Cookson, Natalie; King, Dominic; Arora, Sonal; Darzi, Ara

    2016-01-01

    Background Most hospitals use paging systems as the principal communication system, despite general dissatisfaction by end users. To this end, we developed an app-based communication system (called Hark) to facilitate and improve the quality of interpersonal communication. Objective The objectives of our study were (1) to assess the quality of information transfer using pager- and app-based (Hark) communication systems, (2) to determine whether using mobile phone apps for escalation of care results in additional delays in communication, and (3) to determine how end users perceive mobile phone apps as an alternative to pagers. Methods We recruited junior (postgraduate year 1 and 2) doctors and nurses from a range of specialties and randomly assigned them to 2 groups who used either a pager device or the mobile phone-based Hark app. We asked nurses to hand off simulated patients while doctors were asked to receive handoff information using these devices. The quality of information transfer, time taken to respond to messages, and users’ satisfaction with each device was recorded. Each participant used both devices with a 2-week washout period in between uses. Results We recruited 22 participants (13 nurses, 9 doctors). The quality of the referrals made by nurses was significantly better when using Hark (Hark median 118, range 100–121 versus pager median 77, range 39–104; P=.001). Doctors responded to messages using Hark more quickly than when responding to pagers, although this difference was not statistically significant (Hark mean 86.6 seconds, SD 96.2 versus pager mean 136.5 seconds, SD 201.0; P=.12). Users rated Hark as significantly better on 11 of the 18 criteria of an information transfer device (P<.05) These included “enhances interprofessional efficiency,” “results in less disturbance,” “performed desired functions reliably,” and “allows me to clearly transfer information.” Conclusions Hark improved the quality of transfer of information

  1. Satellite Communications Using Commercial Protocols

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.; Griner, James H.; Dimond, Robert; Frantz, Brian D.; Kachmar, Brian; Shell, Dan

    2000-01-01

    NASA Glenn Research Center has been working with industry, academia, and other government agencies in assessing commercial communications protocols for satellite and space-based applications. In addition, NASA Glenn has been developing and advocating new satellite-friendly modifications to existing communications protocol standards. This paper summarizes recent research into the applicability of various commercial standard protocols for use over satellite and space- based communications networks as well as expectations for future protocol development. It serves as a reference point from which the detailed work can be readily accessed. Areas that will be addressed include asynchronous-transfer-mode quality of service; completed and ongoing work of the Internet Engineering Task Force; data-link-layer protocol development for unidirectional link routing; and protocols for aeronautical applications, including mobile Internet protocol routing for wireless/mobile hosts and the aeronautical telecommunications network protocol.

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

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  3. Aeronautical Knowledge (Selected Articles),

    DTIC Science & Technology

    1981-01-14

    UNCLASSIFIED FTD-ID RSN -12348 Nm m ED I FTD-ID(RS)T-1234-80-- FOREIGN TECHNOLOGY DIVISION AERONAUTICAL KNOWLEDGE (Selected Articles) * DTIC cm. ’- D...of the spacecraft cabin, went through the structure of the eyes of the astronauts, and caused them to see flahig-. The frequency of the flashing was...to tell space travelers of the existence of belts of high radiation end alert them to the danger. Present and future missins must clarify the

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

    NASA Technical Reports Server (NTRS)

    Castiel, David

    1991-01-01

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

  5. A new mHealth communication framework for use in wearable WBANs and mobile technologies.

    PubMed

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

    2015-02-03

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

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

    PubMed Central

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

    2015-01-01

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

  7. Increasing the Lifetime of Mobile WSNs via Dynamic Optimization of Sensor Node Communication Activity

    PubMed Central

    Guimarães, Dayan Adionel; Sakai, Lucas Jun; Alberti, Antonio Marcos; de Souza, Rausley Adriano Amaral

    2016-01-01

    In this paper, a simple and flexible method for increasing the lifetime of fixed or mobile wireless sensor networks is proposed. Based on past residual energy information reported by the sensor nodes, the sink node or another central node dynamically optimizes the communication activity levels of the sensor nodes to save energy without sacrificing the data throughput. The activity levels are defined to represent portions of time or time-frequency slots in a frame, during which the sensor nodes are scheduled to communicate with the sink node to report sensory measurements. Besides node mobility, it is considered that sensors’ batteries may be recharged via a wireless power transmission or equivalent energy harvesting scheme, bringing to the optimization problem an even more dynamic character. We report large increased lifetimes over the non-optimized network and comparable or even larger lifetime improvements with respect to an idealized greedy algorithm that uses both the real-time channel state and the residual energy information. PMID:27657075

  8. The Western Aeronautical Test Range of NASA Ames Research Center

    NASA Technical Reports Server (NTRS)

    Moore, A. L.

    1984-01-01

    An overview of the Western Aeronautical Test Range (WATR) of NASA Ames Research Center (ARC) is presented in this paper. The three WATR facilities are discussed, and three WATR elements - mission control centerns, communications systems, real-time processing and display systems, and tracking systems -are reviewed. The relationships within the NASA WATR, with respect to the NASA aeronautics program, are also discussed.

  9. 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

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

    PubMed

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

    2014-01-01

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

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

    PubMed

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

    2013-01-01

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

  12. NASA's Role in Aeronautics: A Workshop. Volume VI - Aeronautical Research.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC. Assembly of Engineering.

    The central task of a 1980 workshop on the role of the National Aeronautics and Space Administration (NASA) in aeronautics was to examine the relationship of NASA's research capabilities to the state of U.S. aviation and to make recommendations about NASA's future role in aeronautics. Following a brief introduction, the Overview Panel on…

  13. Requirements for a mobile communications satellite system. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    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 ubiquitous 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. While System 2 can operate with leased satellite capacity, Systems 1 and 3 require a dedicated satellite. A major portion of this study is concerned with the design of a satellite for System 1. A weight limit of 10,000 lbs, corresponding to the projected 1990 STS capability, is imposed on the design. Frequency re-use of the allocated spectrum, through multiple satellite beams, is employed to generate the specified system capacity. Both offset-fed and center-fed reflectors are considered. For an assumed 10-MHz allocation and a population of 350,000 subscribers, a two-satellite system is required. The reflector diameters corresponding to offset-fed and center-fed geometries are 46 m and 62 m, respectively. Thus, large-space-structure technology is inherent to the implementation of System 1. In addition to establishing the technical requirements for the three types of satellite systems, the monthly service charge needed to provide a specified return on invested capital is computed. A net present value analysis is used for this purpose.

  14. Feasibility study on radio communications using high altitude radio platform in the stratosphere - Applicability to mobile radio and coverage performance

    NASA Astrophysics Data System (ADS)

    Saruwatari, Taiji

    1991-11-01

    It is possible that a platform, powered by microwaves beamed from the earth, carrying radio equipment and flying in the stratosphere, could be used for radio relay such as satellite communications, terrestrial microwave radio relay, land mobile base stations. In the Communication Research Laboratory, feasibility studies were started in 1989 on application of the high altitude radio platform (HARP) to telecommunications and remote sensing. In this paper, features of mobile radio using the HARP, service coverage of the HARP and cellular configurations are described.

  15. Modeling and performance analysis of an improved movement-based location management scheme for packet-switched mobile communication systems.

    PubMed

    Chung, Yun Won; Kwon, Jae Kyun; Park, Suwon

    2014-01-01

    One of the key technologies to support mobility of mobile station (MS) in mobile communication systems is location management which consists of location update and paging. In this paper, an improved movement-based location management scheme with two movement thresholds is proposed, considering bursty data traffic characteristics of packet-switched (PS) services. The analytical modeling for location update and paging signaling loads of the proposed scheme is developed thoroughly and the performance of the proposed scheme is compared with that of the conventional scheme. We show that the proposed scheme outperforms the conventional scheme in terms of total signaling load with an appropriate selection of movement thresholds.

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

    NASA Technical Reports Server (NTRS)

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

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

  17. Aeronautics and Space Report of the President

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The years 1989 to 1990 activities are reported including human space flight, unmanned expendable launch vehicles, space science and applications, space communications operations, space research and technology, and aeronautics research and technology. Contributions made by the 14 participating government organizations are outline. Each organization's aeronautics and/or space activities for the year are presented. The organizations involved include: (1) NASA; (2) Dept. of Defense; (3) Dept. of Commerce; (4) Dept. of Energy; (5) Dept. of the Interior; (6) Dept. of Agriculture; (7) Federal Communications Commission; (8) Dept. of Transportation; (9) Environmental Protection Agency; (10) National Science Foundation; (11) Smithsonian Institution; (12) Dept. of State; (13) Arms Control and Disarmament; and (14) United States Information Agency.

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

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

    Various design factors for mobile satellite systems, whose aim is to provide worldwide voice and data communications to users with hand-held terminals, are examined. Two network segments are identified - the ground segment (GS) and the space segment (SS) - and are seen to be highly dependent on each other. The overall architecture must therefore be adapted to both of these segments, rather than each being optimized according to its own criteria. Terrestrial networks are grouped and called the terrestrial segment (TS). In the SS, of fundamental importance is the constellation altitude. The effect of the altitude on decisions such as constellation design choice and on network aspects like call handover statistics are fundamental. Orbit resonance is introduced and referred to throughout. It is specifically examined for its useful properties relating to GS/SS connectivities.

  19. Turbo product codes and their application in the fourth-generation mobile communication system

    NASA Astrophysics Data System (ADS)

    He, Yejun; Zhu, Guangxi; Liu, Ying Zhuang; Liu, Jian

    2004-04-01

    In this paper, we firstly present turbo product codes (TPCs) for forward error correction (FEC) coding, including TPCs encoding process and decoding principle, and then compare TPCs with turbo convolutional codes (TCCs) error coding solution. The performance of TPCs is shown to be closer to the Shannon limit than TCCs. Secondly, we introduce TPCs" application in the 4th generation (4G) mobile communication system which is being developed in our country at present. The concept of TPC-OFDM system which promises higher code rate than conventional OFDM is first modified. Finally, simulation results show that the simplified 4G uplink systems offer Bit Error Rate of nearly 0 over IMT-2000 channel at Eb/N0 > 15dB.

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

    NASA Technical Reports Server (NTRS)

    Peach, Robert; Malarky, Alastair

    1990-01-01

    Currently proposed mobile satellite communications systems require a high degree of flexibility in assignment of spectral capacity to different geographic locations. Conventionally this results in poor spectral efficiency which may be overcome by the use of bandwidth switchable filtering. Surface acoustic wave (SAW) technology makes it possible to provide banks of filters whose responses may be contiguously combined to form variable bandwidth filters with constant amplitude and phase responses across the entire band. The high selectivity possible with SAW filters, combined with the variable bandwidth capability, makes it possible to achieve spectral efficiencies over the allocated bandwidths of greater than 90 percent, while retaining full system flexibility. Bandwidth switchable SAW filtering (BSSF) achieves these gains with a negligible increase in hardware complexity.

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

    NASA Technical Reports Server (NTRS)

    Haddad, H. A.

    1948-01-01

    Several antenna design concepts, operating at UHF (821 to 825 MHz transmit and 866 to 870 MHz receive bands), with gain ranging between 6 and 12 dBic, that are suitable for land mobile vehicles are presented. The antennas may be used within CONUS and ALASKA to communicate to and from a geosynchronous satellite. Depending on the type of steering mechanism, the antennas are broken down into three categories; (1) electronically scanned arrays with phase shifters, (2) electronically switched arrays with switchable power dividers/combiners, and (3) mechanically steered arrays. The operating characteristics of two of these design concepts, one a conformal antenna with electronic beam steering and the other a nonconformal design with mechanical steering, were evaluated with regard to two and three satellite system. Cost estimates of various antenna concepts were made and plotted against their overall gain performance.

  2. RGB visible light communication using mobile-phone camera and multi-input multi-output.

    PubMed

    Liang, Kevin; Chow, Chi-Wai; Liu, Yang

    2016-05-02

    Red, green, blue (RGB) light-emitting-diodes (LEDs) are used to increase the visible light communication (VLC) transmission capacity via wavelength-division-multiplexing (WDM), and the color image sensor in mobile phone is used to separate different color signals via a color filter array. However, due to the wide optical bandwidths of the color filters, there is a high spectral overlap among different channels, and a high inter-channel interference (ICI) happens. Here, we propose and demonstrate an RGB VLC transmission using CMOS image sensor with multi-input multi-output (MIMO) technique to mitigate the ICI and retrieve the three independent color channels in the rolling shutter pattern. Data pattern extinction-ratio (ER) enhancement and thresholding are deployed.

  3. Hysteresis in consumer markets with focus on the mobile communications market

    NASA Astrophysics Data System (ADS)

    Twomey, C.

    2008-11-01

    Our aim here is to try to identify hysteresis in the switching patterns of consumers in the Irish mobile phone industry. It was not until the introduction by the Communication Regulator of full-number portability that consumers began to take advantage of the savings that switching mobile phone operator could produce. As with most relatively new industries, the awareness of savings is clouded by a lack of understanding of whats on offer and an underlying fear of change from something they have only just started to comprehend. With people changing company loyalties more frequently than ever at the prospect of better, more cost-efficient services, it is now the million euro question for the phone companies on how close they should match each others' offers to maximize their profits, and what their best pricing strategy should be to obtain an even larger share of the market. Through the use of experimental economics and by modelling switching behaviour using the Preisach model, along with observed and market data, we hope to both pose this problem and start the journey to answering this question.

  4. Constant modulus factorization technique for smart antenna applications in mobile communications

    NASA Astrophysics Data System (ADS)

    van der Veen, Alle-Jan; Paulraj, Arogyaswami

    1994-10-01

    A fundamental problem in sensor array signal processing is to separate and retrieve all independent co-channel signals that arrive at the antenna array. Such problems arise in smart antenna applications for mobile wireless communication, such as interference reduction and in- cell frequency reuse. In a mobile environment, the presence of large delay multipath makes the array manifold poorly defined, and spatial model methods are not applicable. However in case the signals have a constant modulus property (as in FDMA/FM systems like AMPS or TACS), iterative algorithms such as Godard and CMA have been used to retrieve the signals. Because of a non-convex optimization criterion, these algorithms suffer from local minima and random convergence behavior, with no satisfactory remedy known as yet. In this paper, we present an algorithm to compute the exact solution to the underlying constant modulus (CM) factorization problem. With this new approach, it is possible to detect the number of CM signals present at the array, and to retrieve all of them exactly, rejecting other, non-CM signals. Only a modest amount of samples are required. The algorithm is robust in the presence of noise, and is tested on real data, collected from an experimental set-up.

  5. Power attenuation characteristics as switch-over criterion in personal satellite mobile communications

    NASA Technical Reports Server (NTRS)

    Castro, Jonathan P.

    1993-01-01

    A third generation mobile system intends to support communications in all environments (i.e., outdoors, indoors at home or office and when moving). This system will integrate services that are now available in architectures such as cellular, cordless, mobile data networks, paging, including satellite services to rural areas. One way through which service integration will be made possible is by supporting a hierarchical cellular structure based on umbrella cells, macro cells, micro and pico cells. In this type of structure, satellites are part of the giant umbrella cells allowing continuous global coverage, the other cells belong to cities, neighborhoods, and buildings respectively. This does not necessarily imply that network operation of terrestrial and satellite segments interconnect to enable roaming and spectrum sharing. However, the cell concept does imply hand-off between different cell types, which may involve change of frequency. Within this propsective, the present work uses power attenuation characteristics to determine a dynamic criterion that allows smooth transition from space to terrestrial networks. The analysis includes a hybrid channel that combines Rician, Raleigh and Log Normal fading characteristics.

  6. Development of a mobile emergency patient information and imaging communication system based on CDMA-1X EVDO

    NASA Astrophysics Data System (ADS)

    Yang, Keon Ho; Jung, Haijo; Kang, Won-Suk; Jang, Bong Mun; Kim, Joong Il; Han, Dong Hoon; Yoo, Sun-Kook; Yoo, Hyung-Sik; Kim, Hee-Joung

    2006-03-01

    The wireless mobile service with a high bit rate using CDMA-1X EVDO is now widely used in Korea. Mobile devices are also increasingly being used as the conventional communication mechanism. We have developed a web-based mobile system that communicates patient information and images, using CDMA-1X EVDO for emergency diagnosis. It is composed of a Mobile web application system using the Microsoft Windows 2003 server and an internet information service. Also, a mobile web PACS used for a database managing patient information and images was developed by using Microsoft access 2003. A wireless mobile emergency patient information and imaging communication system is developed by using Microsoft Visual Studio.NET, and JPEG 2000 ActiveX control for PDA phone was developed by using the Microsoft Embedded Visual C++. Also, the CDMA-1X EVDO is used for connections between mobile web servers and the PDA phone. This system allows fast access to the patient information database, storing both medical images and patient information anytime and anywhere. Especially, images were compressed into a JPEG2000 format and transmitted from a mobile web PACS inside the hospital to the radiologist using a PDA phone located outside the hospital. Also, this system shows radiological images as well as physiological signal data, including blood pressure, vital signs and so on, in the web browser of the PDA phone so radiologists can diagnose more effectively. Also, we acquired good results using an RW-6100 PDA phone used in the university hospital system of the Sinchon Severance Hospital in Korea.

  7. Adaptive data rate SSMA system for personal and mobile satellite communications

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

    An adaptive data rate SSMA (spread spectrum multiple access) system is proposed for mobile and personal multimedia satellite communications without the aid of system control earth stations. This system has a constant occupied bandwidth and has variable data rates and processing gains to mitigate communication link impairments such as fading, rain attenuation and interference as well as to handle variable data rate on demand. Proof of concept hardware for 6MHz bandwidth transponder is developed, that uses offset-QPSK (quadrature phase shift keying) and MSK (minimum shift keying) for direct sequence spread spectrum modulation and handle data rates of 4k to 64kbps. The RS422 data interface, low rate voice and H.261 video codecs are installed. The receiver is designed with coherent matched filter technique to achieve fast code acquisition, AFC (automatic frequency control) and coherent detection with minimum hardware losses in a single matched filter circuit. This receiver structure facilitates variable data rate on demand during a call. This paper shows the outline of the proposed system and the performance of the prototype equipment.

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

    NASA Technical Reports Server (NTRS)

    Horstein, M.; Barnett, R.

    1981-01-01

    Significant changes in the Nation's electric power systems are expected to result from the integration of new technology, possible during the next decade. Digital communications for monitor and control, exclusive of protective relaying, are expected to double or triple current traffic. A nationwide estimate of 13 Mb/s traffic is projected. Of this total, 8 Mb/s is attributed to the bulk-power system as it is now being operated (4 Mb/s). This traffic could be accommodated by current communications satellites using 3- to 4.5-m-diameter ground terminals costing $35,000 to $70,000 each. The remaining 5-Mb/s traffic is attributed to new technology concepts integrated into the distribution system. Such traffic is not compatible with current satellite technology because it requires small, low-cost ground terminals. Therefore, a high effective isotropic radiated power satellite, such as the one being planned by NASA for the Land Mobile Satellite Service, is required.

  9. A high capacity mobile communications satellite system for the first generation MSS

    NASA Astrophysics Data System (ADS)

    Wiedeman, R. A.

    A low-cost high-capacity dual-band mobile communications satellite system using existing equipment is proposed for the first generation MSS. Cost effectiveness and the requirements of beam optimization and passive intermodulation avoidance dictated the choice of two single band satellites for separate UHF and L-band coverage of North America. Similar designs for the two satellites, based on the Intelsat V and Insat/Arabsat configurations, will achieve over 6000 5-kHz SCPC, communications channels for the system. The 12 beam UHF and 17 beam L-band satellites achieve up to a three-fold frequency reuse of the FCC allocated MSS frequency spectrum. Spacecraft design features include separate 9.1 m antennas for sending and receiving, SAW filters for channel noise attenuation, an integrated bipropellant propulsion system, and a 3.8 kW 10-year electrical power subsystem with a solar array. The satellites are compatible with the STS, Ariane, and other expendable boosters.

  10. Strategies to Develop Communication, Mobility, and Object Manipulation Skills within the Curriculum Domains for Elementary Age Severely Handicapped Students.

    ERIC Educational Resources Information Center

    Hansen, Lucy; Weaver, Judy

    The guide is intended to help teachers of severely and multiply handicapped elementary students develop curriculum and describes techniques for the systematic consideration of needs in the areas of communication, mobility, and object manipulation. An initial section focuses on assessment strategies, including the use of teacher made skill…

  11. Brief Report: A Mobile Application to Treat Prosodic Deficits in Autism Spectrum Disorder and Other Communication Impairments: A Pilot Study

    ERIC Educational Resources Information Center

    Simmons, Elizabeth Schoen; Paul, Rhea; Shic, Frederick

    2016-01-01

    This study examined the acceptability of a mobile application, "SpeechPrompts," designed to treat prosodic disorders in children with ASD and other communication impairments. Ten speech-language pathologists (SLPs) in public schools and 40 of their students, 5-19 years with prosody deficits participated. Students received treatment with…

  12. 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

    ... COMMISSION In the Matter of Certain Personal Data and Mobile Communications Devices and Related Software... Software, Inc. f/k/a NeXT Computer, Inc. of Cupertino, California. The complaint alleges violations of... related software by reason of infringement of certain claims of U.S. Patent Nos. 5,481,721; 5,519,867;...

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

    PubMed

    Morak, Jürgen; Kollmann, Alexander; Schreier, Günter

    2007-01-01

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

  14. Mobile phones in the hospital: improved mobile communication and mitigation of EMI concerns can lead to an overall benefit to healthcare.

    PubMed

    Morrissey, Joseph J

    2004-07-01

    There is a growing trend in hospitals throughout the world to incorporate mobile phones and other wireless technology to offer more efficient, cost effective, and higher quality healthcare. Misunderstanding of mobile phone systems, electromagnetic interference with medical devices, and available management solutions, however, has led to a wide range of inconsistent hospital policies. Recent reviews and commentaries on the subject have provided inconsistent and in some cases factually incorrect information that confuses the issue. At one extreme, unmanaged use of mobile phones in areas where life-critical medical devices are in operation can result in atypical situations that may place patients at risk. At the other extreme, overly-restrictive policies based upon speculation may deny benefits by acting as an obstacle to technology. Overly-restrictive policies may also not address growing and legitimate communication needs of patients and visitors in times of crisis. While it may not be feasible for hospitals to manage every mobile phone handset that is randomly brought into their facility without certain limits on use in areas where life-critical devices are commonly in operation, restrictions are not usually necessary throughout the entire facility. Restrictive policies are also better facilitated when easily accessible areas are designated where mobile phone use is encouraged. Controlled mobile phone systems for use by doctors and staff for hospital-specific communication, by contrast, can operate compatibly throughout the entire hospital facility with appropriate system design and management, even in sensitive areas, and such systems have already been deployed in a number of hospitals throughout the U.S.

  15. 77 FR 28797 - Redundancy of Communications Systems: Backup Power Private Land Mobile Radio Services: Selection...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-16

    ..., Communications common carriers, Communications equipment, Radio, Telecommunications, Telephone, Television... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 12 and 90 Redundancy of Communications Systems: Backup Power Private Land...

  16. 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.

  17. Secure real-time wireless video streaming in the aeronautical telecommunications network

    NASA Astrophysics Data System (ADS)

    Czernik, Pawel; Olszyna, Jakub

    2010-09-01

    As Air Traffic Control Systems move from a voice only environment to one in which clearances are issued via data link, there is a risk that an unauthorized entity may attempt to masquerade as either the pilot or controller. In order to protect against this and related attacks, air-ground communications must be secured. The challenge is to add security in an environment in which bandwidth is limited. The Aeronautical Telecommunications Network (ATN) is an enabling digital network communications technology that addresses capacity and efficiency issues associated with current aeronautical voice communication systems. Equally important, the ATN facilitates migration to free flight, where direct computer-to-computer communication will automate air traffic management, minimize controller and pilot workload, and improve overall aircraft routing efficiency. Protecting ATN communications is critical since safety-of-flight is seriously affected if an unauthorized entity, a hacker for example, is able to penetrate an otherwise reliable communications system and accidentally or maliciously introduce erroneous information that jeopardizes the overall safety and integrity of a given airspace. However, an ATN security implementation must address the challenges associated with aircraft mobility, limited bandwidth communication channels, and uninterrupted operation across organizational and geopolitical boundaries. This paper provides a brief overview of the ATN, the ATN security concept, and begins a basic introduction to the relevant security concepts of security threats, security services and security mechanisms. Security mechanisms are further examined by presenting the fundamental building blocks of symmetric encipherment, asymmetric encipherment, and hash functions. The second part of this paper presents the project of cryptographiclly secure wireless communication between Unmanned Aerial Vehicles (UAV) and the ground station in the ATM system, based on the ARM9 processor

  18. Aeronautical Engineering: 1983 cumulative index

    NASA Technical Reports Server (NTRS)

    1984-01-01

    This bibliography is a cumulative index to the abstracts contained in NASA SP-7037 (158) through NASA SP-7037 (169) of Aeronautical Engineering: A Continuing Bibliography. NASA SP-7037 and its supplements have been compiled through the cooperative efforts of the American Institute of Aeronautics and Astronautics (AIAA) and the National Aeronautics and Space Administration (NASA). This cumulative index includes subject, personal author, corporate source, contract, report number, and accession number indexes.

  19. Aeronautics in NACA and NASA

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Initiated in 1915, the National Advisory Committee for Aeronautics/National Aeronautics and Space Administration (NACA/NASA) aeronautical programs have been the keystone of a sustained U.S. Government, industry, and university research effort which has been a primary factor in the development of our remarkable air transportation systems, the country's largest positive trade balance component, and the world's finest military Air Force. This overview summarizes the flow of events, and the major trends, that have led from the NACA origins to the present NASA Aeronautics program, and indicates some important directions for the years ahead.

  20. NASA's Aeronautics Vision

    NASA Technical Reports Server (NTRS)

    Tenney, Darrel R.

    2004-01-01

    Six long-term technology focus areas are: 1. Environmentally Friendly, Clean Burning Engines. Focus: Develop innovative technologies to enable intelligent turbine engines that significantly reduce harmful emissions while maintaining high performance and increasing reliability. 2. New Aircraft Energy Sources and Management. Focus: Discover new energy sources and intelligent management techniques directed towards zero emissions and enable new vehicle concepts for public mobility and new science missions. 3. Quiet Aircraft for Community Friendly Service. Focus: Develop and integrate noise reduction technology to enable unrestricted air transportation service to all communities. 4. Aerodynamic Performance for Fuel Efficiency. Focus: Improve aerodynamic efficiency,structures and materials technologies, and design tools and methodologies to reduce fuel burn and minimize environmental impact and enable new vehicle concepts and capabilities for public mobility and new science missions. 5. Aircraft Weight Reduction and Community Access. Focus: Develop ultralight smart materials and structures, aerodynamic concepts, and lightweight subsystems to increase vehicle efficiency, leading to high altitude long endurance vehicles, planetary aircraft, advanced vertical and short takeoff and landing vehicles and beyond. 6. Smart Aircraft and Autonomous Control. Focus: Enable aircraft to fly with reduced or no human intervention, to optimize flight over multiple regimes, and to provide maintenance on demand towards the goal of a feeling, seeing, sensing, sentient air vehicle.

  1. Aeronautical Engineering: A continuing bibliography

    NASA Technical Reports Server (NTRS)

    1982-01-01

    This bibliography lists 347 reports, articles and other documents introduced into the scientific and technical information system. Documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated compounds, equipment, and systems are included. Research and development in aerodynamics, aeronautics and ground support equipment for aeronautical vehicles are also included.

  2. Dual-Stack Single-Radio Communication Architecture for UAV Acting As a Mobile Node to Collect Data in WSNs.

    PubMed

    Sayyed, Ali; de Araújo, Gustavo Medeiros; Bodanese, João Paulo; Becker, Leandro Buss

    2015-09-16

    The use of mobile nodes to collect data in a Wireless Sensor Network (WSN) has gained special attention over the last years. Some researchers explore the use of Unmanned Aerial Vehicles (UAVs) as mobile node for such data-collection purposes. Analyzing these works, it is apparent that mobile nodes used in such scenarios are typically equipped with at least two different radio interfaces. The present work presents a Dual-Stack Single-Radio Communication Architecture (DSSRCA), which allows a UAV to communicate in a bidirectional manner with a WSN and a Sink node. The proposed architecture was specifically designed to support different network QoS requirements, such as best-effort and more reliable communications, attending both UAV-to-WSN and UAV-to-Sink communications needs. DSSRCA was implemented and tested on a real UAV, as detailed in this paper. This paper also includes a simulation analysis that addresses bandwidth consumption in an environmental monitoring application scenario. It includes an analysis of the data gathering rate that can be achieved considering different UAV flight speeds. Obtained results show the viability of using a single radio transmitter for collecting data from the WSN and forwarding such data to the Sink node.

  3. Dual-Stack Single-Radio Communication Architecture for UAV Acting As a Mobile Node to Collect Data in WSNs

    PubMed Central

    Sayyed, Ali; Medeiros de Araújo, Gustavo; Bodanese, João Paulo; Buss Becker, Leandro

    2015-01-01

    The use of mobile nodes to collect data in a Wireless Sensor Network (WSN) has gained special attention over the last years. Some researchers explore the use of Unmanned Aerial Vehicles (UAVs) as mobile node for such data-collection purposes. Analyzing these works, it is apparent that mobile nodes used in such scenarios are typically equipped with at least two different radio interfaces. The present work presents a Dual-Stack Single-Radio Communication Architecture (DSSRCA), which allows a UAV to communicate in a bidirectional manner with a WSN and a Sink node. The proposed architecture was specifically designed to support different network QoS requirements, such as best-effort and more reliable communications, attending both UAV-to-WSN and UAV-to-Sink communications needs. DSSRCA was implemented and tested on a real UAV, as detailed in this paper. This paper also includes a simulation analysis that addresses bandwidth consumption in an environmental monitoring application scenario. It includes an analysis of the data gathering rate that can be achieved considering different UAV flight speeds. Obtained results show the viability of using a single radio transmitter for collecting data from the WSN and forwarding such data to the Sink node. PMID:26389911

  4. Mobile Learning Using Mobile Phones

    ERIC Educational Resources Information Center

    Vicente, Paula

    2013-01-01

    The participation in mobile learning programs is conditioned by having/using mobile communication technology. Those who do not have or use such technology cannot participate in mobile learning programs. This study evaluates who are the most likely participants of mobile learning programs by examining the demographic profile and mobile phone usage…

  5. Aeronautics and Space Report of the President

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Nineteen eighty-eight marked the United States' return to space flight with two successful space shuttle launches in September and December, as well as six successful expendable rocket launches. Meanwhile, many other less spectacular but important contributions were made in aeronautics and space by the 14 participating government organizations. Each organization's aeronautics and/or space activities for the year are presented. The organizations involved include: (1) NASA; (2) Department of Defense; (3) Department of Commerce; (4) Department of Energy; (5) Department of the Interior; (6) Department of Agriculture; (7) Federal Communications Commission; (8) Department of Transportation; (9) Environmental Protection Agency; (10) National Science Foundation; (11) Smithsonian Institution; (12) Department of State; (13) Arms Control and Disarmament Agency; and (14) United States Information Agency.

  6. A comparison of metropolitan and non-metropolitan employment characteristics: Indications of the size of non-metropolitan mobile communication services user classes

    NASA Technical Reports Server (NTRS)

    Wilcox, R. E.

    1985-01-01

    The similarities and differences between areas inside and outside U.S. metropolitan areas were evaluated in terms of their commercial/industrial and government employment characteristics. The comparison focuses on the levels, shares, and composition of employment in the commercial/industrial and government sectors that represent potential classes of land mobile communications users. The major findings of the analysis are as follows: (1) non-metropolitan commercial/industrial user classes of land mobile communication services exist in significant numbers; (2) the compositions of non-metropolitan and metropolitan commercial/industrial user classes of land mobile communication services closely resemble each other; (3) non-metropolitan areas have significant levels of the government user classes that represent potential markets for land mobile communication services; and (4) non-metropolitan local governments have a significantly larger proportion of their employment in the primary user classes of private land mobile radio service than do metropolitan local governments.

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

    PubMed

    Reyhani, S M S; Ludwig, Simone A

    2006-10-01

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

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

    NASA Technical Reports Server (NTRS)

    Akle, W.

    1983-01-01

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

  9. [Metabolic changes in cells under electromagnetic radiation of mobile communication systems].

    PubMed

    Iakimenko, I L; Sidorik, E P; Tsybulin, A S

    2011-01-01

    Review is devoted to the analysis of biological effects of microwaves. The results of last years' researches indicated the potential risks of long-term low-level microwaves exposure for human health. The analysis of metabolic changes in living cells under the exposure of microwaves from mobile communication systems indicates that this factor is stressful for cells. Among the reproducible effects of low-level microwave radiation are overexpression of heat shock proteins, an increase of reactive oxygen species level, an increase of intracellular Ca2+, damage of DNA, inhibition of DNA reparation, and induction of apoptosis. Extracellular-signal-regulated kinases ERK and stress-related kinases p38MAPK are involved in metabolic changes. Analysis of current data suggests that the concept of exceptionally thermal mechanism of biological effects of microwaves is not correct. In turn, this raises the question of the need to revaluation of modern electromagnetic standards based on thermal effects of non-ionizing radiation on biological systems.

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

    NASA Technical Reports Server (NTRS)

    Dohi, Tomohiro; Nitta, Kazumasa; Ueda, Takashi

    1993-01-01

    This paper proposes a new type of coherent demodulator, the unique-word (UW)-reverse-modulation type demodulator, for burst signal controlled by voice operated transmitter (VOX) in mobile satellite communication channels. The demodulator has three individual circuits: a pre-detection signal combiner, a pre-detection UW detector, and a UW-reverse-modulation type demodulator. The pre-detection signal combiner combines signal sequences received by two antennas and improves bit energy-to-noise power density ratio (E(sub b)/N(sub 0)) 2.5 dB to yield 10(exp -3) average bit error rate (BER) when carrier power-to-multipath power ratio (CMR) is 15 dB. The pre-detection UW detector improves UW detection probability when the frequency offset is large. The UW-reverse-modulation type demodulator realizes a maximum pull-in frequency of 3.9 kHz, the pull-in time is 2.4 seconds and frequency error is less than 20 Hz. The performances of this demodulator are confirmed through computer simulations and its effect is clarified in real-time experiments at a bit rate of 16.8 kbps using a digital signal processor (DSP).

  11. NASA Aeronautics Research: An Assessment

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The U.S. air transportation system is vital to the economic well-being and security of the United States. To support continued U.S. leadership in aviation, Congress and NASA requested that the National Research Council undertake a decadal survey of civil aeronautics research and technology (R&T) priorities that would help NASA fulfill its responsibility to preserve U.S. leadership in aeronautics technology. In 2006, the National Research Council published the Decadal Survey of Civil Aeronautics. That report presented a set of six strategic objectives for the next decade of aeronautics R&T, and it described 51 high-priority R&T challenges--characterized by five common themes--for both NASA and non-NASA researchers. The National Research Council produced the present report, which assesses NASA's Aeronautics Research Program, in response to the National Aeronautics and Space Administration Authorization Act of 2005 (Public Law 109-155). This report focuses on three sets of questions: 1. How well does NASA's research portfolio implement appropriate recommendations and address relevant high-priority research and technology challenges identified in the Decadal Survey of Civil Aeronautics? If gaps are found, what steps should be taken by the federal government to eliminate them? 2. How well does NASA's aeronautics research portfolio address the aeronautics research requirements of NASA, particularly for robotic and human space exploration? How well does NASA's aeronautics research portfolio address other federal government department/agency non-civil aeronautics research needs? If gaps are found, what steps should be taken by NASA and/or other parts of the federal government to eliminate them? 3. Will the nation have a skilled research workforce and research facilities commensurate with the requirements in (1) and (2) above? What critical improvements in workforce expertise and research facilities, if any, should NASA and the nation make to achieve the goals of NASA

  12. Compact, low profile antennas for MSAT and mini-M and Std-M land mobile satellite communications

    NASA Technical Reports Server (NTRS)

    Strickland, P. C.

    1995-01-01

    CAL Corporation has developed a new class of low profile radiating elements for use in planar phased array antennas. These new elements have been used in the design of a low cost, compact, low profile antenna unit for MSAT and INMARSAT Mini-M land mobile satellite communications. The antenna unit which measures roughly 32 cm in diameter by 5 cm deep incorporates a compact LNA and diplexer unit as well as a complete, low cost, beam steering system. CAL has also developed a low profile antenna unit for INMARSAT-M land mobile satellite communications. A number of these units, which utilize a microstrip patch array design, were put into service in 1994.

  13. NASA's Role in Aeronautics: A Workshop. Volume 6: Aeronautical research

    NASA Technical Reports Server (NTRS)

    1981-01-01

    While each aspect of its aeronautical technology program is important to the current preeminence of the United States in aeronautics, the most essential contributions of NASA derive from its research. Successes and challenges in NASA's efforts to improve civil and military aviation are discussed for the following areas: turbulence, noise, supercritical aerodynamics, computational aerodynamics, fuels, high temperature materials, composite materials, single crystal components, powder metallurgy, and flight controls. Spin offs to engineering and other sciences explored include NASTRAN, lubricants, and composites.

  14. Application of Vision Metrology to In-Orbit Measurement of Large Reflector Onboard Communication Satellite for Next Generation Mobile Satellite Communication

    NASA Astrophysics Data System (ADS)

    Akioka, M.; Orikasa, T.; Satoh, M.; Miura, A.; Tsuji, H.; Toyoshima, M.; Fujino, Y.

    2016-06-01

    Satellite for next generation mobile satellite communication service with small personal terminal requires onboard antenna with very large aperture reflector larger than twenty meters diameter because small personal terminal with lower power consumption in ground base requires the large onboard reflector with high antenna gain. But, large deployable antenna will deform in orbit because the antenna is not a solid dish but the flexible structure with fine cable and mesh supported by truss. Deformation of reflector shape deteriorate the antenna performance and quality and stability of communication service. However, in case of digital beam forming antenna with phased array can modify the antenna beam performance due to adjustment of excitation amplitude and excitation phase. If we can measure the reflector shape precisely in orbit, beam pattern and antenna performance can be compensated with the updated excitation amplitude and excitation phase parameters optimized for the reflector shape measured every moment. Softbank Corporation and National Institute of Information and Communications Technology has started the project "R&D on dynamic beam control technique for next generation mobile communication satellite" as a contracted research project sponsored by Ministry of Internal Affairs and Communication of Japan. In this topic, one of the problem in vision metrology application is a strong constraints on geometry for camera arrangement on satellite bus with very limited space. On satellite in orbit, we cannot take many images from many different directions as ordinary vision metrology measurement and the available area for camera positioning is quite limited. Feasibility of vision metrology application and general methodology to apply to future mobile satellite communication satellite is to be found. Our approach is as follows: 1) Development of prototyping simulator to evaluate the expected precision for network design in zero order and first order 2) Trial

  15. Trade-off between land vehicle antenna cost and gain for satellite mobile communications

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Trade-offs between antenna cost and gain made for nine antennas as a feasibility study for the experimental land mobile satellite system, M-SAT(X) reported. This system is under development by JPL-NASA for a mobile telephone system to be used throughout the continental USA and Alaska. The mobile antenna is a key element in the development of this system.

  16. The Future of Mobile Information and Communication Technology in Austere Environments: A Command and Control Technology Integration Perspective

    DTIC Science & Technology

    2013-03-01

    exchange data. 13 ICT Forecasting “A hiatus exists between inventors who know what they could invent, if they only knew what was wanted, and the...plan of action, but as a tool designed to prepare our AF for impending changes. “By failing to prepare, you are preparing to fail.” ― Benjamin ... Franklin 46 Appendix A: Round 1 Research Instrument Delphi Study on the Future of Mobile Information and Communication Technology (ICT

  17. Simulation and Performance of Data Communication using AMSS

    NASA Technical Reports Server (NTRS)

    Ripamonti, Claudio; Konangi, Vijay K.; Kerczewski, Robert J.

    2006-01-01

    This paper reports the findings of a simulation of the Aeronautical Mobile Satellite Service (AMSS) to be used in the ATN (Aeronautical Telecommunications Network). The models of the protocols used in this simulation were designed to be compliant with the International Civil Aviation Organization (ICAO) Standards and Recommended Practices (SARP). The focus of this research is on the data communication capabilities of the AMSS. The simulated performance characteristics for a region of the AMSS are presented. The results are analyzed to determine the efficiency, limitations, and behavior of this service for the foreseen data communication

  18. 1978 Aeronautics and Space Highlights

    NASA Technical Reports Server (NTRS)

    1978-01-01

    These highlights include the space shuttle, new astronauts, Pioneers to Venus, Voyagers to Jupiter and Saturn, High Energy Astronomy Observatories Space Telescope, Landsat/Seasat, space applications, wind energy research, and aeronautics.

  19. [Burns in an aeronautic environment].

    PubMed

    Rigotti, G

    1979-10-27

    Following an examination of the aetiology of burns in aeronautic environments, the physiopathology, classification and general and local treatment of the burn case is discussed. Special mention is then made of aircraft as an extremely useful means of transport.

  20. All-digital multicarrier demodulators for on-board processing satellites in mobile communication systems

    NASA Astrophysics Data System (ADS)

    Yim, Wan Hung

    Economical operation of future satellite systems for mobile communications can only be fulfilled by using dedicated on-board processing satellites, which would allow both cheap earth terminals and lower space segment costs. With on-board modems and codecs, the up-link and down-link can be optimized separately. An attractive scheme is to use frequency-division multiple access/single chanel per carrier (FDMA/SCPC) on the up-link and time division multiplexing (TDM) on the down-link. This scheme allows mobile terminals to transmit a narrow band, low power signal, resulting in smaller dishes and high power amplifiers (HPA's) with lower output power. On the up-link, there are hundreds to thousands of FDM channels to be demodulated on-board. The most promising approach is the use of all-digital multicarrier demodulators (MCD's), where analog and digital hardware are efficiently shared among channels, and digital signal processing (DSP) is used at an early stage to take advantage of very large scale integration (VLSI) implementation. A MCD consists of a channellizer for separation of frequency division multiplexing (FDM) channels, followed by individual modulators for each channel. Major research areas in MCD's are in multirate DSP, and the optimal estimation for synchronization, which form the basis of the thesis. Complex signal theories are central to the development of structured approaches for the sampling and processing of bandpass signals, which are the foundations in both channellizer and demodulator design. In multirate DSP, polyphase theories replace many ad-hoc, tedious and error-prone design procedures. For example, a polyphase-matrix deep space network frequency and timing system (DFT) channellizer includes all efficient filter bank techniques as special cases. Also, a polyphase-lattice filter is derived, not only for sampling rate conversion, but also capable of sampling phase variation, which is required for symbol timing adjustment in all

  1. Air Force Academy Aeronautics Digest.

    DTIC Science & Technology

    1984-03-01

    map the external flow field on the upper surface of the wing and fuselage, *Major, USAF, Associate Professor of Aeronautics, DFAN 2 7...research effort at the USAF Academy to establish the capabilities and limitations of the seven-hole pressure probe in mapping unknown flow fields. The ... map their locations. III. Apparatus A. Wind Tunnel The Subsonic Wind Tunnel in the Aeronautics Laboratory of

  2. Mobilization

    DTIC Science & Technology

    1987-01-01

    istic and romantic emotionalism that typifies this genre. Longino, James C., et al. “A Study of World War Procurement and Industrial Mobilization...States. Harrisburg, PA: Military Service Publishing Co., 1941. CARL 355.22 J72b. Written in rough prose , this World War II era document explains the

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

    NASA Astrophysics Data System (ADS)

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

    2002-01-01

    Next-generation LEO System Research Center (NeLS) was formed in the end of 1997 as a research group under the Telecommunications Advancement Organization of Japan, in cooperation with the telecommunications operators, manufacturers, universities and governmental research organization. The aim of this project is to develop new technology for global multimedia mobile satellite communications services with a user data rate around 2Mbps for handy terminals. component of the IMT-2000, and the second generation of the big-LEO systems. In prosecuting this project, two-phase approach, phase 1 and phase 2, is considered. Phase 1 is the system definition and development of key technologies. In Phase 2, we plan to verify the developed technology in Phase 1 on space. From this year we shifted the stage to Phase 2, and are now developing the prototype of on-board communication systems for flight tests, which will be planed at around 2006. The satellite altitude is assumed to be 1200 km in order to reduce the number of satellites, to avoid the Van Allen radiation belts and to increase the minimum elevation angle. Ten of the circular orbits with 55 degree of inclination are selected to cover the earth surface from -70 to 70 degree in latitude. 12 satellites are positioned at regular intervals in each orbit. In this case, the minimum elevation angle from the user terminal can be keep more than 20 degree for the visibility of the satellite, and 15 degree for simultaneous visibility of two satellites. Then, NeLS Research Center was focusing on the development of key technologies as the phase 1 project. Four kinds of key technologies; DBF satellite antenna, optical inter-satellite link system, satellite network technology with on-board ATM switch and variable rate modulation were selected. Satellite Antenna Technology: Development of on-board direct radiating active phased array antenna with digital beam forming technology would be one of the most important breakthroughs for the

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

    NASA Technical Reports Server (NTRS)

    Sreenath, K.; Feher, K.

    1990-01-01

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

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

    NASA Astrophysics Data System (ADS)

    Sreenath, K.; Feher, K.

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

  6. A proposed architecture for a satellite-based mobile communications network - The lowest three layers

    NASA Technical Reports Server (NTRS)

    Yan, T. Y.; Naderi, F. M.

    1986-01-01

    Architecture for a commercial mobile satellite network is proposed. The mobile satellite system (MSS) is composed of a network management center, mobile terminals, base stations, and gateways; the functions of each component are described. The satellite is a 'bent pipe' that performs frequency translations, and it has multiple UHF beams. The development of the MSS design based on the seven-layer open system interconnection model is examined. Consideration is given to the functions of the physical, data link, and network layers and the integrated adaptive mobile access protocol.

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

    NASA Technical Reports Server (NTRS)

    Arcidiancono, Antonio

    1990-01-01

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

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

    PubMed

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

    2015-07-01

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

  9. Student Perceptions of a Mobile Augmented Reality Game and Willingness to Communicate in Japanese

    ERIC Educational Resources Information Center

    Shea, Andrea Misao

    2014-01-01

    Communication is a key component in learning a second language (L2). As important as the "ability" to communicate in the L2 is the willingness to use the L2 or, what has been identified in the literature as "Willingness to Communicate" (WTC). Language is best learned when situated in, and based on, real-life experiences.…

  10. The United States regional mobile satellite system

    NASA Astrophysics Data System (ADS)

    Anderson, Roy E.; Cooperman, Richard S.

    Commercial interests within the United States and Canada are preparing to implement cooperative systems that will provide land and aeronautical mobile satellite services in those two countries and in Mexico. Wide bandwidth, linear satellites ('bent pipe transponders') in geostationary orbit will be built and operated by a consortium of companies in the United States. The consortium will act as a carrier's carrier, leasing bandwidth and power to resellers and private radio leasees who will tailor the ground systems and signal characteristics to the needs of end users. A variety of voice, data, and position fixing services will add new dimensions to mobile communications throughout North America.

  11. Compressibility Effects in Aeronautical Engineering

    NASA Technical Reports Server (NTRS)

    Stack, John

    1941-01-01

    Compressible-flow research, while a relatively new field in aeronautics, is very old, dating back almost to the development of the first firearm. Over the last hundred years, researches have been conducted in the ballistics field, but these results have been of practically no use in aeronautical engineering because the phenomena that have been studied have been the more or less steady supersonic condition of flow. Some work that has been done in connection with steam turbines, particularly nozzle studies, has been of value, In general, however, understanding of compressible-flow phenomena has been very incomplete and permitted no real basis for the solution of aeronautical engineering problems in which.the flow is likely to be unsteady because regions of both subsonic and supersonic speeds may occur. In the early phases of the development of the airplane, speeds were so low that the effects of compressibility could be justifiably ignored. During the last war and immediately after, however, propellers exhibited losses in efficiency as the tip speeds approached the speed of sound, and the first experiments of an aeronautical nature were therefore conducted with propellers. Results of these experiments indicated serious losses of efficiency, but aeronautical engineers were not seriously concerned at the time became it was generally possible. to design propellers with quite low tip. speeds. With the development of new engines having increased power and rotational speeds, however, the problems became of increasing importance.

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

    NASA Technical Reports Server (NTRS)

    Anderson, R. E.

    1979-01-01

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

  13. Spreading the Load: Mobile Information and Communications Technologies and Their Effect on Information Overload

    ERIC Educational Resources Information Center

    Allen, David K.; Shoard, M.

    2005-01-01

    Introduction: We report on a small-scale research project which examined the impact of mobile technologies on the users' experience of information overload. The project focused on a group of worker who have had relatively little attention in both the mobile technology and information overload literatures: senior managers. Method: The case study…

  14. [Psychophysiological indicators for children using mobile phones. Communication 1. Current state of the problem].

    PubMed

    Khorseva, N I; Grigor'ev, Iu G; Gorbunova, N V

    2011-01-01

    An overview of the epidemiological and experimental evidence for exposure of humans and animals to electromagnetic radiation produced by mobile phones is provided. The effects of mobile phone radiation on the child's body are considered in detail. It has been shown that the children's organism is more sensitive to this kind of exposure than the adult one.

  15. Private Land Mobile Radio Services--Federal Communications Commission. Final rule.

    PubMed

    1982-09-16

    The Commission adopts a Second Report and Order releasing reserved radio spectrum in the 806-821/851-866 MHz bands for Private Land Mobile Radio Service use. The rules adopted provide enhanced flexibility in radio system design and user options. The action is necessary to satisfy land mobile spectrum needs across the country.

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

    PubMed

    Khan, Shamshad

    2014-01-01

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

  17. The Mobile College Community: A Study of Adult Learners' Adoption and Use of Digital Communication Technologies on the Campuses of Florida's Community Colleges

    ERIC Educational Resources Information Center

    Weidert, John William

    2012-01-01

    Rapid advancements in technology and the proliferation of mobile communication devices available in the marketplace require that community college administrators and teachers better understand levels of digital communication technology adoption and how adult learners currently use them. Such an understanding is necessary to developing the…

  18. National Advisory Committee for Aeronautics

    NASA Technical Reports Server (NTRS)

    1938-01-01

    NASA was created from the National Advisory Committee on Aeronautics in 1958. This is a photo of the members of the advisory board of NACA in 1938. NACA was the governmental organization charged with the supervision and conduct of scientific laboratory research in aeronautics. Its laboratories located at Langley Field, Virginia, provide new knowledge underlying the continuous improvement in the performance, efficiency, and safety of American aircraft. At this meeting Dr. Joesph S. Ames, President Emeritus of John Hopkins University, was re-elected Chairman, and Dr. Vannevar Bush, President- elect of the Carnegie Institution of Washington, was elected Vice Chairman. Dr. Ames' re-election as chairman was a recognition of his outstanding contributions to the science of aeronautics. He has been the leading scientific member of the Committee for over twenty-three years and chairman for eleven years. Under his visionary leadership the great laboratories of the N.A.C.A. at Langley Field have been developed. Left to Right: Hon. C. M. Hester, Administrator, Civil Aeronautics Authority Captain S. M. Kraus, U.S.N. Brig. General A. W. Robins, Chief, Materiel Division, Army Air Corps. Dr. L.J. Biggs, Director, National Bureau of Standards Dr. E.P. Warner Dr. Orville Wright Dr. Joesph S. Ames, Chairman Dr. C.J. Abbot, Secretary, Smithsonian Institution J.F. Victory, Secretary Rear Adm. A.B. Cook, U.S.N., Chief, Bureau Aeronautics Authority Dr. Vannevar Bush Dr. J.C. Hunsaker Dr. G.W. Lewis, Director of Aeronautical Research. Absent: Col. Charles A. Lindbergh and Maj. Gen. H. 'Hap' Arnold, Chief, Army Air Corps. One Vacany: U.S. Weather Bureau.

  19. A medical application integrating remote 3D visualization tools to access picture archiving and communication system on mobile devices.

    PubMed

    He, Longjun; Ming, Xing; Liu, Qian

    2014-04-01

    With computing capability and display size growing, the mobile device has been used as a tool to help clinicians view patient information and medical images anywhere and anytime. However, for direct interactive 3D visualization, which plays an important role in radiological diagnosis, the mobile device cannot provide a satisfactory quality of experience for radiologists. This paper developed a medical system that can get medical images from the picture archiving and communication system on the mobile device over the wireless network. In the proposed application, the mobile device got patient information and medical images through a proxy server connecting to the PACS server. Meanwhile, the proxy server integrated a range of 3D visualization techniques, including maximum intensity projection, multi-planar reconstruction and direct volume rendering, to providing shape, brightness, depth and location information generated from the original sectional images for radiologists. Furthermore, an algorithm that changes remote render parameters automatically to adapt to the network status was employed to improve the quality of experience. Finally, performance issues regarding the remote 3D visualization of the medical images over the wireless network of the proposed application were also discussed. The results demonstrated that this proposed medical application could provide a smooth interactive experience in the WLAN and 3G networks.

  20. 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

  1. Implementation of Inmarsat mobile satcom systems

    NASA Technical Reports Server (NTRS)

    Haugli, HANS-CHR.

    1990-01-01

    Described here is the new mobile satcom systems being implemented by Inmarsat. Inmarsat has traditionally provided professional communication to ships and is now actively implementing new systems for use on land, in the air, and at sea. These new systems can provide near global communication for anyone on the move. By 1993, four new systems will provide telephony, telex, data, group call and facsimile at affordable cost to a very wide range of users. A table giving the main technical parameters for Inmarsat Aeronautical, Inmarsat-B, C, and M systems is provided.

  2. Implementation of Inmarsat mobile satcom systems

    NASA Astrophysics Data System (ADS)

    Haugli, Hans-Chr.

    Described here is the new mobile satcom systems being implemented by Inmarsat. Inmarsat has traditionally provided professional communication to ships and is now actively implementing new systems for use on land, in the air, and at sea. These new systems can provide near global communication for anyone on the move. By 1993, four new systems will provide telephony, telex, data, group call and facsimile at affordable cost to a very wide range of users. A table giving the main technical parameters for Inmarsat Aeronautical, Inmarsat-B, C, and M systems is provided.

  3. Satellite Communications for ATM

    NASA Technical Reports Server (NTRS)

    Shamma, Mohammed A.

    2003-01-01

    This presentation is an overview on Satellite Communication for the Aeronautical Telecommunication Management (ATM) research. Satellite Communications are being considered by the FAA and NASA as a possible alternative to the present and future ground systems supporting Air Traffic Communications. The international Civil Aviation Organization (ICAO) have in place Standards and Recommended Practices (SARPS) for the Aeronautical Mobile Satellite Services (AMSS) which is mainly derived from the pre-existing Inmarsat service that has been in service since the 1980s. The Working Group A of the Aeronautical Mobile Communication Panel of ICAO has also been investigating SARPS for what is called the Next Generation Satellite Service (NGSS) which conforms less to the Inmarsat based architecture and explores wider options in terms of satellite architectures. Several designs are being proposed by Firms such as Boeing, ESA, NASA that are geared toward full or secondary usage of satellite communications for ATM. Satellite communications for ATM can serve several purposes ranging from primary usage where ground services would play a minimal backup role, to an integrated solution where it will be used to cover services, or areas that are less likely to be supported by the proposed and existing ground infrastructure. Such Integrated roles can include usage of satellite communications for oceanic and remote land areas for example. It also can include relieving the capacity of the ground network by providing broadcast based services of Traffic Information Services messages (TIS-B), or Flight Information Services (FIS-B) which can take a significant portion of the ground system capacity. Additionally, satellite communication can play a backup role to support any needs for ground replacement, or additional needed capacity even after the new digital systems are in place. The additional bandwidth that can be provided via satellite communications can also open the door for many new

  4. Field testing of a remote controlled robotic tele-echo system in an ambulance using broadband mobile communication technology.

    PubMed

    Takeuchi, Ryohei; Harada, Hiroshi; Masuda, Kohji; Ota, Gen-ichiro; Yokoi, Masaki; Teramura, Nobuyasu; Saito, Tomoyuki

    2008-06-01

    We report the testing of a mobile Robotic Tele-echo system that was placed in an ambulance and successfully transmitted clear real time echo imaging of a patient's abdomen to the destination hospital from where this device was being remotely operated. Two-way communication between the paramedics in this vehicle and a doctor standing by at the hospital was undertaken. The robot was equipped with an ultrasound probe which was remotely controlled by the clinician at the hospital and ultrasound images of the patient were transmitted wirelessly. The quality of the ultrasound images that were transmitted over the public mobile telephone networks and those transmitted over the Multimedia Wireless Access Network (a private networks) were compared. The transmission rate over the public networks and the private networks was approximately 256 Kbps, 3 Mbps respectively. Our results indicate that ultrasound images of far higher definition could be obtained through the private networks.

  5. Control of an indoor autonomous mobile communications relay via antenna diversity

    NASA Astrophysics Data System (ADS)

    Griffin, Brian; Fierro, Rafael; Palunko, Ivana

    2010-04-01

    Presented here is a motion planning scheme for enabling a quadrotor to serve as an autonomous communications relay in indoor/GPS-denied environments. Using antenna selection diversity, the quadrotor is able to optimize its location in the communication chain so as to maximize the link throughput. Measurements of the communications field drive a gradient descent algorithm that moves the quadrotor to an optimal location while avoiding obstacles, all without the use of positioning data.

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

    PubMed

    Chen, Shih-Hao; Chow, Chi-Wai

    2014-12-15

    A novel color-filter-free visible-light communication (VLC) system using red-green-blue (RGB) light emitting diode (LED) and mobile-phone camera is proposed and demonstrated for the first time. A feature matching method, which is based on the scale-invariant feature transform (SIFT) algorithm for the received grayscale image is used instead of the chromatic information decoding method. The proposed method is simple and saves the computation complexity. The signal processing is based on the grayscale image computation; hence neither color-filter nor chromatic channel information is required. A proof-of-concept experiment is performed and high performance channel recognition is achieved.

  7. Demonstration of long-distance hazard-free wearable EEG monitoring system using mobile phone visible light communication.

    PubMed

    Rachim, Vega Pradana; Jiang, Yubing; Lee, Hyeon-Seok; Chung, Wan-Young

    2017-01-23

    A wearable electroencephalogram (EEG) is a small mobile device used for long-term brain monitoring systems. Applications of these systems include fatigue monitoring, mental/emotional monitoring, and brain-computer interfaces. However, the usage of wireless wearable EEG systems is limited due to the risks posed by the wireless RF communication radiation in a long-term exposure to the human brain. A novel microwave radiation-free system was developed by integrating visible light communication technology into a wearable EEG device. In this work, we investigated the system's performance in transmitting EEG data at different illuminance level and proposed an algorithm that functions at low illuminance levels for increased transmission distance. Using a 30 Hz smartphone camera, the proposed system was able to transmit 2.4 kbps of error-free EEG data up to 4 meter, which is equal to ~300 lux using an aspheric focus lens.

  8. 14 CFR 1251.560 - Communications.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 5 2012-01-01 2012-01-01 false Communications. 1251.560 Section 1251.560 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NONDISCRIMINATION ON BASIS OF HANDICAP... Aeronautics and Space Administration § 1251.560 Communications. (a) The agency shall take appropriate steps...

  9. 14 CFR 1251.560 - Communications.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Communications. 1251.560 Section 1251.560 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NONDISCRIMINATION ON BASIS OF HANDICAP... Aeronautics and Space Administration § 1251.560 Communications. (a) The agency shall take appropriate steps...

  10. 14 CFR § 1251.560 - Communications.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 5 2014-01-01 2014-01-01 false Communications. § 1251.560 Section § 1251.560 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NONDISCRIMINATION ON BASIS OF... the National Aeronautics and Space Administration § 1251.560 Communications. (a) The agency shall...

  11. 1997 NASA Academy in Aeronautics

    NASA Technical Reports Server (NTRS)

    Andrisani, Dominick, II

    1998-01-01

    The NASA Academy in Aeronautics at the Dryden Flight Research Center (DFRC) was a ten-week summer leadership training program conducted for the first time in the summer of 1997. Funding was provided by a contract between DFRC and Purdue University. Mr. Lee Duke of DFRC was the contract monitor, and Professor Dominick Andrisani was the principal investigator. Five student research associates participated in the program. Biographies of the research associates are given in Appendix 1. Dominick Andrisani served as Dean of the NASA Academy in Aeronautics. NASA Academy in Aeronautics is a unique summer institute of higher learning that endeavors to provide insight into all of the elements that make NASA aeronautical research possible. At the same time the Academy assigns the research associate to be mentored by one of NASA!s best researchers so that they can contribute towards an active flight research program. Aeronautical research and development are an investment in the future, and NASA Academy is an investment in aeronautical leaders of the future. The Academy was run by the Indiana Space Grant Consortium at Purdue in strategic partnership with the National Space Grant College and Fellowship Program. Research associates at the Academy were selected with help from the Space Grant Consortium that sponsored the research associate. Research associate stipend and travel to DFRC were paid by the students' Space Grant Consortium. All other student expenses were paid by the Academy. Since the Academy at DFRC had only five students the opportunity for individual growth and attention was unique in the country. About 30% of the working time and most of the social time of the students were be spent as a "group" or "team." This time was devoted to exchange of ideas, on forays into the highest levels of decision making, and in executing aeronautical research. This was done by interviewing leaders throughout the aerospace industry, seminars, working dinners, and informal

  12. Aeronautics. America in Space: The First Decade.

    ERIC Educational Resources Information Center

    Anderton, David A.

    The major research and developments in aeronautics during the late 1950's and 1960's are reviewed descriptively with a minimum of technical content. Topics covered include aeronautical research, aeronautics in NASA, The National Advisory Committee for Aeronautics, the X-15 Research Airplane, variable-sweep wing design, the Supersonic Transport…

  13. 14 CFR 77.35 - Aeronautical studies.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Aeronautical studies. 77.35 Section 77.35 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRSPACE OBJECTS AFFECTING NAVIGABLE AIRSPACE (Eff. until 1-18-11) Aeronautical Studies of Effect of...

  14. 14 CFR 77.35 - Aeronautical studies.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical studies. 77.35 Section 77.35 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRSPACE OBJECTS AFFECTING NAVIGABLE AIRSPACE Aeronautical Studies of Effect of Proposed Construction on...

  15. Relationships between Emotional States and Emoticons in Mobile Phone Email Communication in Japan

    ERIC Educational Resources Information Center

    Kato, Shogo; Kato, Yuuki; Scott, Douglass

    2009-01-01

    Three related studies conducted on the role of emotional transfer in email messages were studied in order to better understand Japanese college students' online communications and their broader participation in online communications. The first study investigated users' initiatives in preventing emotional misunderstandings when sending email.…

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

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.

    2007-01-01

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

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

    NASA Technical Reports Server (NTRS)

    Ivancic, William D.

    2006-01-01

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

  18. NASA/University Conference on Aeronautics

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The proceedings of a conference on the future of aeronautics are presented. The subjects discussed include the following: (1) aeronautics and the education of the engineer, (2) technical trends in aeronautics, and (3) the role of the university in aeronautics. The technical trends in aeronautics are concerned with aircraft noise control, the effect of the aircraft on the environment, airborne electronics for automated flight, and trends in aircraft design.

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

    PubMed Central

    Mars, Maurice

    2015-01-01

    Abstract Background: We investigated the use of third-generation (3G) mobile communications to provide telehealth services in remote health clinics in rural KwaZulu-Natal, South Africa. Materials and Methods: We specified a minimal set of services as our use case that would be representative of typical activity and to provide a baseline for analysis of network performance. Services included database access to manage chronic disease, local support and management of patients (to reduce unnecessary travel to the hospital), emergency care (up to 8 h for an ambulance to arrive), e-mail, access to up-to-date information (Web), and teleclinics. We made site measurements at a representative set of health clinics to determine the type of coverage (general packet radio service [GPRS]/3G), its capabilities to support videoconferencing (H323 and Skype™ [Microsoft, Redmond, WA]) and audio (Skype), and throughput for transmission control protocol (TCP) to gain a measure of application performance. Results: We found that none of the remote health clinics had 3G service. The GPRS service provided typical upload speed of 44 kilobits per second (Kbps) and download speed of 64 Kbps. This was not sufficient to support any form of videoconferencing. We also observed that GPRS had significant round trip time (RTT), in some cases in excess of 750 ms, and this led to slow start-up for TCP applications. Conclusions: We found audio was always so broken as to be unusable and further observed that many applications such as Web access would fail under conditions of very high RTT. We found some health clinics were so remote that they had no mobile service. 3G, where available, had measured upload speed of 331 Kbps and download speed of 446 Kbps and supported videoconferencing and audio at all sites, but we frequently experienced 3G changing to GPRS. We conclude that mobile communications currently provide insufficient coverage and capability to provide reliable clinical services and

  20. Trust models for efficient communication in Mobile Cloud Computing and their applications to e-Commerce

    NASA Astrophysics Data System (ADS)

    Pop, Florin; Dobre, Ciprian; Mocanu, Bogdan-Costel; Citoteanu, Oana-Maria; Xhafa, Fatos

    2016-11-01

    Managing the large dimensions of data processed in distributed systems that are formed by datacentres and mobile devices has become a challenging issue with an important impact on the end-user. Therefore, the management process of such systems can be achieved efficiently by using uniform overlay networks, interconnected through secure and efficient routing protocols. The aim of this article is to advance our previous work with a novel trust model based on a reputation metric that actively uses the social links between users and the model of interaction between them. We present and evaluate an adaptive model for the trust management in structured overlay networks, based on a Mobile Cloud architecture and considering a honeycomb overlay. Such a model can be useful for supporting advanced mobile market-share e-Commerce platforms, where users collaborate and exchange reliable information about, for example, products of interest and supporting ad-hoc business campaigns

  1. Mobility Prediction Progressive Routing (MP2R), a Cross-Layer Design for Inter-Vehicle Communication

    NASA Astrophysics Data System (ADS)

    Tang, Suhua; Kadowaki, Naoto; Obana, Sadao

    In this paper we analyze the characteristics of vehicle mobility and propose a novel Mobility Prediction Progressive Routing (MP2R) protocol for Inter-Vehicle Communication (IVC) that is based on crosslayer design. MP2R utilizes the additional gain provided by the directional antennas to improve link quality and connectivity; interference is reduced by the directional transmission. Each node learns its own position and speed and that of other nodes, and performs position prediction. (i) With the predicted progress and link quality, the forwarding decision of a packet is locally made, just before the packet is actually transmitted. In addition the load at the forwarder is considered in order to avoid congestion. (ii) The predicted geographic direction is used to control the beam of the directional antenna. The proposed MP2R protocol is especially suitable for forwarding burst traffic in highly mobile environments. Simulation results show that MP2R effectively reduces Packet Error Ratio (PER) compared with both topology-based routing (AODV [1], FSR [2]) and normal progressive routing (NADV [18]) in the IVC scenarios.

  2. A communication analysis of community mobilization on the Warm Springs Indian Reservation.

    PubMed

    McLean, S

    1997-01-01

    This article is an analysis of the community mobilization process used at the Warm Springs Indian Reservation as part of a health education campaign. Using the community education model proposed by Freire (1970), it examines the techniques employed to involve community members in radio, print, and public speaking fora, as well as the interpersonal interviews and listening techniques employed by the educators to gain entree to the community. Credibility emerged as a major issue to be addressed in the mobilization process. Other findings include the value of involving community leaders, persistence, and frankness. Caution is urged in implementing the Freirian model without regard to unique community traditions and relationships.

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

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

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

  4. Progress Toward National Aeronautics Goals

    NASA Technical Reports Server (NTRS)

    Russo, Carlo J.; Sehra, Arun K.

    1999-01-01

    NASA has made definitive progress towards achieving several bold U.S. goals in aeronautics related to air breathing engines. The advanced technologies developed towards these goals span applications from general aviation to large subsonic and supersonic aircraft. The proof of successful technology development is demonstrated through successful technology transfer to U.S. industry and projected fleet impact. Specific examples of progress are discussed that quantifies the achievement towards these goals. In addition, a more detailed vision for NASA aeronautics is defined and key strategic issues are explored which invite international and national debate and involvement especially in reduced environmental impact for subsonic and supersonic aircraft, dramatic new capabilities in general aviation engines, and reduced development cycle time and costs.

  5. Aeronautics and space report of the President, 1982 activities

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Achievements of the space program are summerized in the area of communication, Earth resources, environment, space sciences, transportation, aeronautics, and space energy. Space program activities of the various deprtments and agencies of the Federal Government are discussed in relation to the agencies' goals and policies. Records of U.S. and world spacecraft launchings, successful U.S. launches for 1982, U.S. launched applications and scientific satellites and space probes since 1975, U.S. and Soviet manned spaceflights since 1961, data on U.S. space launch vehicles, and budget summaries are provided. The national space policy and the aeronautical research and technology policy statements are included.

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

    ERIC Educational Resources Information Center

    Gasiorek, Jessica; van de Poel, Kris

    2012-01-01

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

  7. 75 FR 63445 - Vessel Monitoring Systems; Approved Mobile Transmitting Units and Communications Service...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-15

    .... SUPPLEMENTARY INFORMATION: VMS Mobile Transceiver Units Faria WatchDog 750VMS With VTERM The Faria WatchDog... when the vessel goes to sea. The Faria WatchDog 750VMS has omni-directional Iridium, GPS, and GSM/GPRS... WatchDog Inc., P.O. Box 486, Uncasville, CT 06382, mark@fariawatchdog.net ; (860) 608-5875; (fax):...

  8. Local Sociality in Young People's Mobile Communications: A Korean Case Study

    ERIC Educational Resources Information Center

    Yoon, Kyongwon

    2006-01-01

    Drawing upon ethnographic data, this article explores how young Koreans appropriate mobile phones. By examining the role of local norms of sociality among young people, the study shows that this "individualizing" technology is articulated through "traditionalizing" forces. Despite dominant representations of young people's…

  9. Aeronautical applications of high-temperature superconductors

    NASA Technical Reports Server (NTRS)

    Turney, George E.; Luidens, Roger W.; Uherka, Kenneth; Hull, John

    1989-01-01

    The successful development of high-temperature superconductors (HTS) could have a major impact on future aeronautical propulsion and aeronautical flight vehicle systems. A preliminary examination of the potential application of HTS for aeronautics indicates that significant benefits may be realized through the development and implementation of these newly discovered materials. Applications of high-temperature superconductors (currently substantiated at 95 k) were envisioned for several classes of aeronautical systems, including subsonic and supersonic transports, hypersonic aircraft, V/STOL aircraft, rotorcraft, and solar, microwave and laser powered aircraft. Introduced and described are the particular applications and potential benefits of high-temperature superconductors as related to aeronautics and/or aeronautical systems.

  10. Aeronautical applications of high-temperature superconductors

    NASA Technical Reports Server (NTRS)

    Turney, George E.; Luidens, Roger W.; Uherka, Kenneth; Hull, John

    1989-01-01

    The successful development of high-temperature superconductors (HTS) could have a major impact on future aeronautical propulsion and aeronautical flight vehicle systems. A preliminary examination of the potential application of HTS for aeronautics indicates that significant benefits may be realized through the development and implementation of these newly discovered materials. Applications of high-temperature superconductors (currently substantiated at 95 K) were envisioned for several classes of aeronautical systems, including subsonic and supersonic transports, hypersonic aircraft, V/STOL aircraft, rotorcraft, and solar, microwave and laser powered aircraft. Introduced and described are the particular applications and potential benefits of high-temperature superconductors as related to aeronautics and/or aeronautical systems.

  11. Communications

    NASA Technical Reports Server (NTRS)

    Stouffer, Donald D.

    1990-01-01

    Communication in its many forms is a critical component for an effective Space Grant Program. Good communication is needed within individual Space Grant College/Consortia, for example between consortium affiliates and the consortium program office. Effective communication between the several programs, NASA Headquarters, and NASA field centers also is required. Further, communication among the above program elements, industry, local and state government, and the public also are necessary for meeting program objectives.

  12. Multi-purpose HealthCare Telemedicine Systems with mobile communication link support

    PubMed Central

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

    2003-01-01

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

  13. Developing a Conceptual Unmanned Aerial Vehicle Communications Mobile AD Hoc Network Simulation Model

    DTIC Science & Technology

    2002-06-01

    Elizabeth Royer described the Ad Hoc On-Demand Distance Vector (AODV) routing protocol as “providing quick and efficient route establishment between...Network.” Thesis, Naval Postgraduate School, December 2000. 8. Das, Samir R., Perkins, Charles E., and Royer, Elizabeth M. “ The Ad-hoc On-Demand...Lidong. “Securing Ad Hoc Networks.” Paper Cornell University, Itaca, New York, NY. 16. Corson , Scott S., and Macker, J. “Mobile Ad Hoc

  14. Communication.

    ERIC Educational Resources Information Center

    Hancock, Alan

    An informal introduction to the study of communication deals with the major topics in the field. It presents basic theories of communication and language, reviews how language takes on meaning, explains the stimulus-response and Piaget theories of learning, and presents major theories dealing with communications and society. These theories include…

  15. PERFORMANCE CRITERIA, A SYSTEM OF COMMUNICATION FOR MOBILIZING BUILDING INDUSTRY RESOURCES.

    ERIC Educational Resources Information Center

    JACQUES, RICHARD G.

    A PROGRAM TO TEST AND DEMONSTRATE THE EFFICACY OF PERFORMANCE CRITERIA FOR UNIVERSITY BUILDING DESIGN AND CONSTRUCTION IS UNDER WAY IN NEW YORK STATE UNDER THE AUSPICES OF THE NEW YORK STATE UNIVERSITY CONSTRUCTION FUND. THE PROGRAM IS TO RESULT IN AN EXTENSIVE LIBRARY OF PERFORMANCE CRITERIA TO AID COMMUNICATION WITH ALL SECTORS OF THE BUILDING…

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

    ERIC Educational Resources Information Center

    Lowe, Sarah; Stuedahl, Dagny

    2014-01-01

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

  17. Aeronautical record : no. 1 (to June, 1923)

    NASA Technical Reports Server (NTRS)

    1923-01-01

    "...considerations have prompted us to pay special attention to the development of aeronautical industries and aerial navigation as a commercial enterprise and to publish an analytical review of events in the aeronautical world and of the attendant problems."

  18. Program of Research in Aeronautics

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A prospectus of the educational and research opportunities available at the Joint Institute for Advancement of Flight Sciences, operated at NASA Langley Research Center in conjunction with George Washington University's School of Engineering and Applied Sciences is presented. Requirements of admission to various degree programs are given as well as the course offerings in the areas of acoustics, aeronautics, environmental modelling, materials science, and structures and dynamics. Research facilities for each field of study are described. Presentations and publications (including dissertations and theses) generated by each program are listed as well as faculty members visting scientists and engineers.

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

    PubMed

    Thors, B; Hansson, B; Törnevik, C

    2009-07-07

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

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

    PubMed

    Russo, P; Cerri, G; Vespasiani, V

    2010-12-01

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

  1. Brief Report: A Mobile Application to Treat Prosodic Deficits in Autism Spectrum Disorder and Other Communication Impairments: A Pilot Study.

    PubMed

    Simmons, Elizabeth Schoen; Paul, Rhea; Shic, Frederick

    2016-01-01

    This study examined the acceptability of a mobile application, SpeechPrompts, designed to treat prosodic disorders in children with ASD and other communication impairments. Ten speech-language pathologists (SLPs) in public schools and 40 of their students, 5-19 years with prosody deficits participated. Students received treatment with the software over eight weeks. Pre- and post-treatment speech samples and student engagement data were collected. Feedback on the utility of the software was also obtained. SLPs implemented the software with their students in an authentic education setting. Student engagement ratings indicated students' attention to the software was maintained during treatment. Although more testing is warranted, post-treatment prosody ratings suggest that SpeechPrompts has potential to be a useful tool in the treatment of prosodic disorders.

  2. NASA's aeronautics research and technology base

    NASA Technical Reports Server (NTRS)

    1979-01-01

    NASA's research technology base in aeronautics is assessed in terms of: (1) US aeronautical technology needs and requirements in the future; (2) objectives of the aeronautics program; (3) magnitude and scope of the program; and (4) research and technology performed by NASA and other research organizations.

  3. Questions & Answers about Aeronautics and Space.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    Answers to 27 questions about aeronautics, space, and the National Aeronautics and Space Administration (NASA) are provided in this pamphlet. Among the topics dealt with in these questions are: costs of the space program; NASA's role in aeronautics; benefits received from the space program; why the United States hasn't developed means of rescuing…

  4. 14 CFR 61.105 - Aeronautical knowledge.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aeronautical knowledge. 61.105 Section 61.105 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... log ground training from an authorized instructor or complete a home-study course on the...

  5. 14 CFR 61.97 - Aeronautical knowledge.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.97 Section 61.97 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN... ground training from an authorized instructor or complete a home-study course on the...

  6. 14 CFR 61.97 - Aeronautical knowledge.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aeronautical knowledge. 61.97 Section 61.97 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRMEN... ground training from an authorized instructor or complete a home-study course on the...

  7. 14 CFR 61.125 - Aeronautical knowledge.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.125 Section 61.125 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... log ground training from an authorized instructor, or complete a home-study course, on...

  8. 14 CFR 61.105 - Aeronautical knowledge.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Aeronautical knowledge. 61.105 Section 61.105 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... log ground training from an authorized instructor or complete a home-study course on the...

  9. 14 CFR 61.125 - Aeronautical knowledge.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Aeronautical knowledge. 61.125 Section 61.125 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED... log ground training from an authorized instructor, or complete a home-study course, on...

  10. Decoding mobile-phone image sensor rolling shutter effect for visible light communications

    NASA Astrophysics Data System (ADS)

    Liu, Yang

    2016-01-01

    Optical wireless communication (OWC) using visible lights, also known as visible light communication (VLC), has attracted significant attention recently. As the traditional OWC and VLC receivers (Rxs) are based on PIN photo-diode or avalanche photo-diode, deploying the complementary metal-oxide-semiconductor (CMOS) image sensor as the VLC Rx is attractive since nowadays nearly every person has a smart phone with embedded CMOS image sensor. However, deploying the CMOS image sensor as the VLC Rx is challenging. In this work, we propose and demonstrate two simple contrast ratio (CR) enhancement schemes to improve the contrast of the rolling shutter pattern. Then we describe their processing algorithms one by one. The experimental results show that both the proposed CR enhancement schemes can significantly mitigate the high-intensity fluctuations of the rolling shutter pattern and improve the bit-error-rate performance.

  11. Routing Protocols to Minimize the Number of Route Disconnections for Communication in Mobile Ad Hoc Networks

    DTIC Science & Technology

    2009-09-01

    Broch , "DSR: The Dynamic Source Routing Protocol for Multi-hop Wireless Ad hoc Networks," in Ad hoc Networking, Chapter 5, C. E. Perkins, Eds. Addison...Project Report: 09/23/2008 to 09/22/2009 W911NF-08-2-0061 References [I] J. Broch , D. A. Maltz, D. B. Johnson, Y. C. Hu and J. Jetcheva, "A...and Mobile Computing, Vol. 2, pp. 723 - 726, Sept. 2005. [4] D. B. Johnson, D. A. Maltz and J. Broch , "DSR: The Dynamic Source Routing Protocol for

  12. Aeronautical audio broadcasting via satellite

    NASA Technical Reports Server (NTRS)

    Tzeng, Forrest F.

    1993-01-01

    A system design for aeronautical audio broadcasting, with C-band uplink and L-band downlink, via Inmarsat space segments is presented. Near-transparent-quality compression of 5-kHz bandwidth audio at 20.5 kbit/s is achieved based on a hybrid technique employing linear predictive modeling and transform-domain residual quantization. Concatenated Reed-Solomon/convolutional codes with quadrature phase shift keying are selected for bandwidth and power efficiency. RF bandwidth at 25 kHz per channel, and a decoded bit error rate at 10(exp -6) with E(sub b)/N(sub o) at 3.75 dB are obtained. An interleaver, scrambler, modem synchronization, and frame format were designed, and frequency-division multiple access was selected over code-division multiple access. A link budget computation based on a worst-case scenario indicates sufficient system power margins. Transponder occupancy analysis for 72 audio channels demonstrates ample remaining capacity to accommodate emerging aeronautical services.

  13. Tactical Mobile Communications (Communications tactiques mobiles)

    DTIC Science & Technology

    1999-11-01

    modem function. both the complexity of the power supply and the It typically includes modulation and demodulation, current consumption which can become...respectively. As power Figure 4. The performances of BPSK, QPSK and is increased, these 3 modulation techniques will DPSK modulation techniques in... modulations . Power efficient modulation types less. In addition to the sky-wave channel, the HF include direct sequence spread spectrum and M-ary surface wave

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

    NASA Technical Reports Server (NTRS)

    Woo, K.

    1982-01-01

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

  15. Modulation and Synchronization for Aeronautical Telemetry

    NASA Astrophysics Data System (ADS)

    Shaw, Christopher G.

    Aeronautical telemetry systems have historically been implemented with constant envelope modulations like CPM. Shifts in system constraints including reduced available bandwidth and increased throughput demands have caused many in the field to reevaluate traditional methods and design practices. This work examines the costs and benefits of using APSK for aeronautical telemetry instead of CPM. Variable rate turbo codes are used to improve the power efficiency of 16- and 32-APSK. Spectral regrowth in nonlinear power amplifiers when driven by non-constant envelope modulation is also considered. Simulation results show the improved spectral efficiency of this modulation scheme over those currently defined in telemetry standards. Additionally, the impact of transitioning from continuous transmission to burst-mode is considered. Synchronization loops are ineffective in burst-mode communication. Data-aided feedforward algorithms can be used to estimate offsets in carrier phase, frequency, and symbol timing between the transmitter and the receiver. If a data-aided algorithm is used, a portion of the transmitted signal is devoted to a known sequence of pilot symbols. Optimum pilot sequences for the three synchronization parameters are obtained analytically and numerically for different system constraints. The alternating sequence is shown to be optimal given a peak power constraint. Alternatively, synchronization can be accomplished using blind algorithms that do not rely on a priori knowledge of a pilot sequence. If blind algorithms are used, the observation interval can be longer than for data-aided algorithms. There are combinations of pilot sequence length and packet length where data-aided algorithms perform better than blind algorithms and vice versa. The conclusion is that a sequential arrangement of blind algorithms operating over an entire burst performs better than a CRB-achieving data-aided algorithm operating over a short pilot sequence.

  16. Aeronautics and Space Report of the President: Fiscal Year 1996 Activities

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Topics considered include: (1) Space launch activities: space shuttle missions; expendable launch vehicles. (2) Space science: astronomy and space physics; solar system exploration. (3) Space flight and technology: life and microgravity sciences; space shuttle technology; reuseable launch vehicles; international space station; energy; safety and mission assurance; commercial development and regulation of space; surveillance. (4) Space communications: communications satellites; space network; ground networks; mission control and data systems. (5) Aeronautical activities: technology developments; air traffic control and navigation; weather-related aeronautical activities; flight safety and security; aviation medicine and human factors. (6) Studies of the planet earth: terrestrial studies and applications: atmospheric studies: oceanographic studies; international aeronautical and space activities; and appendices.

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

    PubMed

    Obregón, Rafael; Waisbord, Silvio

    2010-01-01

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

  18. Comparison of thresholding schemes for visible light communication using mobile-phone image sensor.

    PubMed

    Liu, Yang; Chow, Chi-Wai; Liang, Kevin; Chen, Hung-Yu; Hsu, Chin-Wei; Chen, Chung-Yen; Chen, Shih-Hao

    2016-02-08

    Based on the rolling shutter effect of the complementary metal-oxide-semiconductor (CMOS) image sensor, bright and dark fringes can be observed in each received frame. By demodulating the bright and dark fringes, the visible light communication (VLC) data logic can be retrieved. However, demodulating the bright and dark fringes is challenging as there is a high data fluctuation and large extinction ratio (ER) variation in each frame due. Hence proper thresholding scheme is needed. In this work, we propose and compare experimentally three thresholding schemes; including third-order polynomial curve fitting, iterative scheme and quick adaptive scheme. The evaluation of these three thresholding schemes is performed.

  19. Mobile satellite regulation in the United States

    NASA Astrophysics Data System (ADS)

    Levin, Lon C.; Sonnenfeldt, Walter H.

    During the last decade, the U.S. FCC has developed the regulatory structure for the provision of mobile services via satellite. In May 1989, the FCC awarded American Mobile Satellite Corporation (AMSC) a license to provide the full range of domestic mobile satellite services in the U.S. At that time, the FCC reaffirmed the U.S. mobile satellite industry structure and spectrum allocations that had been adopted previously. Also in May 1989, the FCC authorized the Communications Satellite Corporation (COMSAT), the U.S. Signatory to Inmarsat, to provide international aeronautical satellite service via the Inmarsat system. Earlier in 1989, the FCC permitted the use of Ku-band satellites to provide messaging and tracking services. In the mid-1980's, the FCC established the Radiodetermination Satellite Service and awarded licenses. Among the mobile satellite matters currently facing the FCC are whether additional spectrum should be allocated for domestic 'generic' mobile satellite services, the regulatory structure for the provision of mobile satellite service on an interim basis before AMSC launches its dedicated satellites, and whether to authorize a low earth orbit satellite system to provide mobile data service.

  20. Mobile satellite regulation in the United States

    NASA Technical Reports Server (NTRS)

    Levin, Lon C.; Sonnenfeldt, Walter H.

    1990-01-01

    During the last decade, the U.S. FCC has developed the regulatory structure for the provision of mobile services via satellite. In May 1989, the FCC awarded American Mobile Satellite Corporation (AMSC) a license to provide the full range of domestic mobile satellite services in the U.S. At that time, the FCC reaffirmed the U.S. mobile satellite industry structure and spectrum allocations that had been adopted previously. Also in May 1989, the FCC authorized the Communications Satellite Corporation (COMSAT), the U.S. Signatory to Inmarsat, to provide international aeronautical satellite service via the Inmarsat system. Earlier in 1989, the FCC permitted the use of Ku-band satellites to provide messaging and tracking services. In the mid-1980's, the FCC established the Radiodetermination Satellite Service and awarded licenses. Among the mobile satellite matters currently facing the FCC are whether additional spectrum should be allocated for domestic 'generic' mobile satellite services, the regulatory structure for the provision of mobile satellite service on an interim basis before AMSC launches its dedicated satellites, and whether to authorize a low earth orbit satellite system to provide mobile data service.

  1. System capacity and economic modeling computer tool for satellite mobile communications systems

    NASA Technical Reports Server (NTRS)

    Wiedeman, Robert A.; Wen, Doong; Mccracken, Albert G.

    1988-01-01

    A unique computer modeling tool that combines an engineering tool with a financial analysis program is described. The resulting combination yields a flexible economic model that can predict the cost effectiveness of various mobile systems. Cost modeling is necessary in order to ascertain if a given system with a finite satellite resource is capable of supporting itself financially and to determine what services can be supported. Personal computer techniques using Lotus 123 are used for the model in order to provide as universal an application as possible such that the model can be used and modified to fit many situations and conditions. The output of the engineering portion of the model consists of a channel capacity analysis and link calculations for several qualities of service using up to 16 types of earth terminal configurations. The outputs of the financial model are a revenue analysis, an income statement, and a cost model validation section.

  2. Path loss analysis in millimeter wave cellular systems for urban mobile communications

    NASA Astrophysics Data System (ADS)

    Rajagopalan, Ramesh; Hoffman, Mitchell

    2016-09-01

    The proliferation in the number of mobile devices and developments in cellular technology has led to an ever increasing demand for mobile data. The global bandwidth shortage facing wireless carriers today has motivated research for fifth generation (5G) cellular systems. In recent years, millimeter wave (mmW) frequencies between 30 and 300 GHz are being considered as a promising technology for 5G systems. Such systems can offer superior user experience by providing data rates that exceed one Gigabit per second and latencies lower than a millisecond. However, there is little research about cellular mmW propagation in densely populated urban environments. Understanding the radio channel is a primary requirement for optimal design of mmW systems. Radio propagation in mmW systems faces significant challenges due to rapidly varying channel conditions and intermittent connectivity. In this paper, we study the propagation of mmW spectrum in an urban environment. We use a statistical model to simulate an urban environment with diverse building distributions. We perform extensive simulations to analyze the path loss behavior for both line of sight (LOS) and non line of sight (NLOS) conditions for 28 GHZ and 73 GHZ mmW frequencies. We observe that the path loss approximates a logarithmic fit for both LOS and NLOS environments. Our simulations show that the omnidirectional free space path loss is approximately 30 dB higher for mmW systems compared to current 3G PP cellular systems. To address this challenge, we propose using highly directional horn antennas with beam forming for reducing the path loss.

  3. Cooperating mobile robots

    DOEpatents

    Harrington, John J.; Eskridge, Steven E.; Hurtado, John E.; Byrne, Raymond H.

    2004-02-03

    A miniature mobile robot provides a relatively inexpensive mobile robot. A mobile robot for searching an area provides a way for multiple mobile robots in cooperating teams. A robotic system with a team of mobile robots communicating information among each other provides a way to locate a source in cooperation. A mobile robot with a sensor, a communication system, and a processor, provides a way to execute a strategy for searching an area.

  4. Weather Information Communication Technologies for Increased Safety and Mobility in the National Airspace System

    NASA Technical Reports Server (NTRS)

    Hilderman, Don R.

    2006-01-01

    The purpose of the NASA Glenn Research Center Weather Information Communications (WINCOMM) project was to develop advanced communications and information technologies to enable the high-quality and timely dissemination of strategic weather information between the flight deck and ground users as well as tactical turbulence hazard information between relevant aircraft and to the ground. This report will document and reference accomplishments on the dissemination of weather information during the en route phase of flight from ground-based weather information providers to the flight deck (ground-to-air), from airborne meteorological sensors to ground users (air-to-ground), and weather turbulence and icing hazard information between relevant aircraft (air-to-air). In addition, references in this report will demonstrate the architecture necessary to implement and perform successful transmission and reception of weather information to the cockpit, show that weather information flow does not impact "normal" traffic, demonstrate the feasibility of operational implementation, and lay foundation for future data link development.

  5. Communicate!

    ERIC Educational Resources Information Center

    Chase, Stuart

    This ten chapter book is designed to provide high school students with an understanding of basic communication processes. The first five chapters include discussions of language development, function, and acquisition in relation to both human and non-human communication. The sixth chapter contains specimen linguistic analyses of speech and…

  6. US development and commercialization of a North American mobile satellite service

    NASA Technical Reports Server (NTRS)

    Arnold, Ray J.; Gray, Valerie; Freibaum, Jerry

    1990-01-01

    U.S. policies promoting applications and commercialization of space technology for the 'benefit of mankind,' and emphasis on international competitiveness, formed the basis of NASA's Mobile Satellite (MSAT) R&D and user experiments program to develop a commercial U.S. Mobile Satellite Service. Exemplifying this philosophy, the MSAT program targets the reduction of technical, regulatory, market, and financial risks that inhibit commercialization. The program strategy includes industry and user involvement in developing and demonstrating advanced technologies, regulatory advocacy, and financial incentives to industry. Approximately two decades of NASA's satellite communications development and demonstrations have contributed to the emergence of a new multi-billion dollar industry for land, aeronautical, and maritime mobile communications via satellite. NASA's R&D efforts are now evolving from the development of 'enabling' ground technologies for VHF, UHF, and L-Band mobile terminals, to Ka-Band terminals offering additional mobility and user convenience.

  7. Communication

    NASA Technical Reports Server (NTRS)

    Griner, James

    2010-01-01

    NASA s communication work for the UAS Command and Control area will build upon work currently being conducted under NASA Recovery Act funds. Communication portions of UAS NextGen ConOps, Stateof- the-Art assessment, and Gap Analysis. Preliminary simulations for UAS CNPC link scalability assessment. Surrogate UAS aircraft upgrades. This work will also leverage FY10 in-guide funding for communication link model development. UAS are currently managed through exceptions and are operating using DoD frequencies for line-of-sight (LOS) and satellite-based communications links, low-power LOS links in amateur bands, or unlicensed Instrument/Scientific/Medical (ISM) frequencies. None of these frequency bands are designated for Safety and Regularity of Flight. No radio-frequency (RF) spectrum has been allocated by the International Telecommunications Union (ITU) specifically for UAS command and control links, for either LOS or Beyond LOS (BLOS) communication.

  8. RecoverNow: Feasibility of a Mobile Tablet-Based Rehabilitation Intervention to Treat Post-Stroke Communication Deficits in the Acute Care Setting

    PubMed Central

    Corbett, Dale; Finestone, Hillel M.; Hatcher, Simon; Lumsden, Jim; Momoli, Franco; Shamy, Michel C. F.; Stotts, Grant; Swartz, Richard H.; Yang, Christine

    2016-01-01

    Background Approximately 40% of patients diagnosed with stroke experience some degree of aphasia. With limited health care resources, patients’ access to speech and language therapies is often delayed. We propose using mobile-platform technology to initiate early speech-language therapy in the acute care setting. For this pilot, our objective was to assess the feasibility of a tablet-based speech-language therapy for patients with communication deficits following acute stroke. Methods We enrolled consecutive patients admitted with a stroke and communication deficits with NIHSS score ≥1 on the best language and/or dysarthria parameters. We excluded patients with severe comprehension deficits where communication was not possible. Following baseline assessment by a speech-language pathologist (SLP), patients were provided with a mobile tablet programmed with individualized therapy applications based on the assessment, and instructed to use it for at least one hour per day. Our objective was to establish feasibility by measuring recruitment rate, adherence rate, retention rate, protocol deviations and acceptability. Results Over 6 months, 143 patients were admitted with a new diagnosis of stroke: 73 had communication deficits, 44 met inclusion criteria, and 30 were enrolled into RecoverNow (median age 62, 26.6% female) for a recruitment rate of 68% of eligible participants. Participants received mobile tablets at a mean 6.8 days from admission [SEM 1.6], and used them for a mean 149.8 minutes/day [SEM 19.1]. In-hospital retention rate was 97%, and 96% of patients scored the mobile tablet-based communication therapy as at least moderately convenient 3/5 or better with 5/5 being most “convenient”. Conclusions Individualized speech-language therapy delivered by mobile tablet technology is feasible in acute care. PMID:28002479

  9. 1981 Aeronautics and Space Highlights

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This video presentation covers Shuttle flights 1 and 2, Spacelab, mobile workstation, Voyager 2 Saturn, Infrared Astronomy Satellite, Hubble Space Telescope, Kuiper Airborne Observatory, High Altitude Earth Survey, Landsat, aerodynamic research, electric cars, wind energy, XV-15, Quiet Shorthaul Research Aircraft, X-14 BVTOL, 40 x 80 Wind Tunnel, and turboprop research.

  10. Comparison of VDL Modes in the Aeronautical Telecommunications Network

    NASA Technical Reports Server (NTRS)

    Bretmersky, Steven; Konangi, Vijay K.; Kerczewski, Robert J.

    2002-01-01

    VHF Digital Link (VDL) has been identified as a method of communication between aircraft and ground stations in the Aeronautical Telecommunications Network (ATN). Three different modes of VDL have been suggested for implementation. Simulations were conducted to compare the data transfer capabilities of VDL Modes 2, 3, and 4. These simulations focus on up to 50 aircraft communicating with a single VDL ground station. The data traffic is generated by the standard File Transfer Protocol (FTP) and Hyper Text Transfer Protocol (HTTP) applications in the aircraft. Comparisons of the modes are based on the number of files and pages transferred and the response time.

  11. Output power distributions of terminals in a 3G mobile communication network.

    PubMed

    Persson, Tomas; Törnevik, Christer; Larsson, Lars-Eric; Lovén, Jan

    2012-05-01

    The objective of this study was to examine the distribution of the output power of mobile phones and other terminals connected to a 3G network in Sweden. It is well known that 3G terminals can operate with very low output power, particularly for voice calls. Measurements of terminal output power were conducted in the Swedish TeliaSonera 3G network in November 2008 by recording network statistics. In the analysis, discrimination was made between rural, suburban, urban, and dedicated indoor networks. In addition, information about terminal output power was possible to collect separately for voice and data traffic. Information from six different Radio Network Controllers (RNCs) was collected during at least 1 week. In total, more than 800000 h of voice calls were collected and in addition to that a substantial amount of data traffic. The average terminal output power for 3G voice calls was below 1 mW for any environment including rural, urban, and dedicated indoor networks. This is <1% of the maximum available output power. For data applications the average output power was about 6-8 dB higher than for voice calls. For rural areas the output power was about 2 dB higher, on average, than in urban areas.

  12. Information spreading on mobile communication networks: A new model that incorporates human behaviors

    NASA Astrophysics Data System (ADS)

    Ren, Fei; Li, Sai-Ping; Liu, Chuang

    2017-03-01

    Recently, there is a growing interest in the modeling and simulation based on real social networks among researchers in multi-disciplines. Using an empirical social network constructed from the calling records of a Chinese mobile service provider, we here propose a new model to simulate the information spreading process. This model takes into account two important ingredients that exist in real human behaviors: information prevalence and preferential spreading. The fraction of informed nodes when the system reaches an asymptotically stable state is primarily determined by information prevalence, and the heterogeneity of link weights would slow down the information diffusion. Moreover, the sizes of blind clusters which consist of connected uninformed nodes show a power-law distribution, and these uninformed nodes correspond to a particular portion of nodes which are located at special positions in the network, namely at the edges of large clusters or inside the clusters connected through weak links. Since the simulations are performed on a real world network, the results should be useful in the understanding of the influences of social network structures and human behaviors on information propagation.

  13. Comparative international analysis of radiofrequency exposure surveys of mobile communication radio base stations.

    PubMed

    Rowley, Jack T; Joyner, Ken H

    2012-01-01

    This paper presents analyses of data from surveys of radio base stations in 23 countries across five continents from the year 2000 onward and includes over 173,000 individual data points. The research compared the results of the national surveys, investigated chronological trends and compared exposures by technology. The key findings from this data are that irrespective of country, the year and cellular technology, exposures to radio signals at ground level were only a small fraction of the relevant human exposure standards. Importantly, there has been no significant increase in exposure levels since the widespread introduction of 3G mobile services, which should be reassuring for policy makers and negate the need for post-installation measurements at ground level for compliance purposes. There may be areas close to antennas where compliance levels could be exceeded. Future potential work includes extending the study to additional countries, development of cumulative exposure distributions and investigating the possibility of linking exposure measurements to population statistics to assess the distribution of exposure levels relative to population percentiles.

  14. Comparative international analysis of radiofrequency exposure surveys of mobile communication radio base stations

    PubMed Central

    Rowley, Jack T; Joyner, Ken H

    2012-01-01

    This paper presents analyses of data from surveys of radio base stations in 23 countries across five continents from the year 2000 onward and includes over 173,000 individual data points. The research compared the results of the national surveys, investigated chronological trends and compared exposures by technology. The key findings from this data are that irrespective of country, the year and cellular technology, exposures to radio signals at ground level were only a small fraction of the relevant human exposure standards. Importantly, there has been no significant increase in exposure levels since the widespread introduction of 3G mobile services, which should be reassuring for policy makers and negate the need for post-installation measurements at ground level for compliance purposes. There may be areas close to antennas where compliance levels could be exceeded. Future potential work includes extending the study to additional countries, development of cumulative exposure distributions and investigating the possibility of linking exposure measurements to population statistics to assess the distribution of exposure levels relative to population percentiles. PMID:22377680

  15. Power prediction in mobile communication systems using an optimal neural-network structure.

    PubMed

    Gao, X M; Gao, X Z; Tanskanen, J A; Ovaska, S J

    1997-01-01

    Presents a novel neural-network-based predictor for received power level prediction in direct sequence code division multiple access (DS/CDMA) systems. The predictor consists of an adaptive linear element (Adaline) followed by a multilayer perceptron (MLP). An important but difficult problem in designing such a cascade predictor is to determine the complexity of the networks. We solve this problem by using the predictive minimum description length (PMDL) principle to select the optimal numbers of input and hidden nodes. This approach results in a predictor with both good noise attenuation and excellent generalization capability. The optimized neural networks are used for predictive filtering of very noisy Rayleigh fading signals with 1.8 GHz carrier frequency. Our results show that the optimal neural predictor can provide smoothed in-phase and quadrature signals with signal-to-noise ratio (SNR) gains of about 12 and 7 dB at the urban mobile speeds of 5 and 50 km/h, respectively. The corresponding power signal SNR gains are about 11 and 5 dB. Therefore, the neural predictor is well suitable for power control applications where ldquodelaylessrdquo noise attenuation and efficient reduction of fast fading are required.

  16. Physicians appeals on the dangers of mobile communication--what is the evidence? Assessment of public health data.

    PubMed

    Zur Nieden, Anja; Dietz, Corinna; Eikmann, Thomas; Kiefer, Jürgen; Herr, Caroline E W

    2009-11-01

    In October 2002 German physicians appealed to persons in the field of health care, politicians and the public with "great concern" ("Freiburger Appell", "Appeal of Freiburg") claiming "soaring incidences of symptoms and diseases in the general population" to be causally related to the "commence of radio (wave) burden", i.e. due to mobile radio technology. This first example was followed by several further appeals published nationally and Europe-wide up until today. The aim of the present paper is an evaluation of the scientific literature and databases to check incidence and prevalence of symptoms and diseases stated in the appeals to have "dramatically increased" or to have appeared in "greater frequency" in adults. If the allegations were true a clear time-trend should show up since the start of widely-used mobile communication technology. The following health conditions were considered: Alzheimer's disease, dementia, sleep disturbances, tinnitus, cerebrovascular disease, ischemic heart-diseases, headache, migraine. Data on the incidence of these conditions were assessed from 1993 through at least 2005. For this, a systematic search by keywords was performed in the online-database of the National Library of Medicine (pubmed) and other national and international (European and US) databases. For none of the considered symptoms or diseases a "dramatic increase" was found to have occurred since 1993. Because of the different diagnoses and terms used in the studies, direct comparability is somewhat difficult. Indeed, with the data available no time related increases and surely no "dramatic increase" can be identified, even if the limited comparability is considered. This analysis strongly suggests that the allegations of the quoted appeals are not supported by public health data.

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

    PubMed

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

    2015-01-01

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

  18. Simple Switched-Beam Array Antenna System for Mobile Satellite Communications

    NASA Astrophysics Data System (ADS)

    Basari; Purnomo, M. Fauzan E.; Saito, Kazuyuki; Takahashi, Masaharu; Ito, Koichi

    This paper presents a simple antenna system for land vehicle communication aimed at Engineering Test Satellite-VIII (ETS-VIII) applications. The developed antenna system which designed for mounting in a vehicle is compact, light weight and offers simple satellite-tracking operation. This system uses a microstrip patch array antenna, which includes onboard-power divider and switching circuit for antenna feeding control, due to its low profile. A Global Positioning System (GPS) receiver is constructed to provide accurate information on the vehicle's position and bearing during traveling. The personal computer (PC) interfaces as the control unit and data acquisition, which were specifically designed for this application, allow the switching circuit control as well as the retrieving of the received power levels. In this research, the antenna system was firstly examined in an anechoic chamber for S parameter, axial ratio, and radiation characteristics. Satisfactory characteristics were obtained. As for beam-tracking of antenna, it was examined in the anechoic chamber with the gain above 5dBic and the axial ratio below 3dB. Moreover, good received power levels for tracking the ETS-VIII satellite in outdoor measurement, were confirmed.

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

    NASA Astrophysics Data System (ADS)

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

    2013-09-01

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

  20. Aeronautical Engineering: A Continuing Bibliography. Supplement 421

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This supplemental issue of Aeronautical Engineering, A Continuing Bibliography with Indexes (NASA/SP#2000-7037) lists reports, articles, and other documents recently announced in the NASA STI Database. The coverage includes documents on the engineering and theoretical aspects of design, construction, evaluation, testing, operation, and performance of aircraft (including aircraft engines) and associated components, equipment, and systems. It also includes research and development in aerodynamics, aeronautics, and ground support equipment for aeronautical vehicles.

  1. Quantifying socio-economic indicators in developing countries from mobile phone communication data: applications to Côte d’Ivoire

    SciTech Connect

    Mao, Huina; Shuai, Xin; Ahn, Yong -Yeol; Bollen, Johan

    2015-10-13

    The widespread adoption of mobile devices that record the communications, social relations, and movements of billions of individuals in great detail presents unique opportunities for the study of social structures and human dynamics at very large scales. This is particularly the case for developing countries where social and economic data can be hard to obtain and is often too sparse for real-time analytics. In this paper, we leverage mobile call log data from Côte d’Ivoire to analyze the relations between its nation-wide communications network and the socio-economic dynamics of its regional economies. We introduce the CallRank indicator to quantify the relative importance of an area on the basis of call records, and show that a region’s ratio of in- and out-going calls can predict its income level. We detect a communication divide between rich and poor regions of Côte d’Ivoire, which corresponds to existing socio-economic data. Our results demonstrate the potential of mobile communication data to monitor the economic development and social dynamics of low-income developing countries in the absence of extensive econometric and social data. Finally, our work may support efforts to stimulate sustainable economic development and to reduce poverty and inequality.

  2. Quantifying socio-economic indicators in developing countries from mobile phone communication data: applications to Côte d’Ivoire

    DOE PAGES

    Mao, Huina; Shuai, Xin; Ahn, Yong -Yeol; ...

    2015-10-13

    The widespread adoption of mobile devices that record the communications, social relations, and movements of billions of individuals in great detail presents unique opportunities for the study of social structures and human dynamics at very large scales. This is particularly the case for developing countries where social and economic data can be hard to obtain and is often too sparse for real-time analytics. In this paper, we leverage mobile call log data from Côte d’Ivoire to analyze the relations between its nation-wide communications network and the socio-economic dynamics of its regional economies. We introduce the CallRank indicator to quantify themore » relative importance of an area on the basis of call records, and show that a region’s ratio of in- and out-going calls can predict its income level. We detect a communication divide between rich and poor regions of Côte d’Ivoire, which corresponds to existing socio-economic data. Our results demonstrate the potential of mobile communication data to monitor the economic development and social dynamics of low-income developing countries in the absence of extensive econometric and social data. Finally, our work may support efforts to stimulate sustainable economic development and to reduce poverty and inequality.« less

  3. 14 CFR 61.125 - Aeronautical knowledge.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... and effects of exceeding aircraft performance limitations; (9) Use of aeronautical charts and a..., and emergency operations appropriate to the aircraft; (14) Night and high-altitude operations;...

  4. 14 CFR 61.125 - Aeronautical knowledge.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... and effects of exceeding aircraft performance limitations; (9) Use of aeronautical charts and a..., and emergency operations appropriate to the aircraft; (14) Night and high-altitude operations;...

  5. 14 CFR 61.125 - Aeronautical knowledge.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... and effects of exceeding aircraft performance limitations; (9) Use of aeronautical charts and a..., and emergency operations appropriate to the aircraft; (14) Night and high-altitude operations;...

  6. Mobile Router Technology Development

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

    Cisco Systems and NASA have been performing joint research on mobile routing technology under a NASA Space Act Agreement. Cisco developed mobile router technology and provided that technology to NASA for applications to aeronautic and space-based missions. NASA has performed stringent performance testing of the mobile router, including the interaction of routing and transport-level protocols. This paper describes mobile routing, the mobile router, and some key configuration parameters. In addition, the paper describes the mobile routing test network and test results documenting the performance of transport protocols in dynamic routing environments.

  7. 76 FR 16643 - NASA Advisory Council; Aeronautics Committee; Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-24

    ... From the Federal Register Online via the Government Publishing Office NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NASA Advisory Council; Aeronautics Committee; Meeting AGENCY: National Aeronautics... Committee Act, Public Law 92-463, as amended, the National Aeronautics and Space Administration announces...

  8. 77 FR 61432 - NASA Advisory Council; Aeronautics Committee; Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-09

    ... From the Federal Register Online via the Government Publishing Office NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NASA Advisory Council; Aeronautics Committee; Meeting AGENCY: National Aeronautics... Committee Act, Public Law 92-463, as amended, the National Aeronautics and Space Administration announces...

  9. 75 FR 50782 - NASA Advisory Council; Aeronautics Committee; Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-17

    ... From the Federal Register Online via the Government Publishing Office NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NASA Advisory Council; Aeronautics Committee; Meeting AGENCY: National Aeronautics... Committee Act, Public Law 92-463, as amended, the National Aeronautics and Space Administration announces...

  10. 76 FR 40753 - NASA Advisory Council; Aeronautics Committee; Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-11

    ... From the Federal Register Online via the Government Publishing Office NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NASA Advisory Council; Aeronautics Committee; Meeting AGENCY: National Aeronautics... Committee Act, Public Law 92-463, as amended, the National Aeronautics and Space Administration announces...

  11. 75 FR 41240 - NASA Advisory Council; Aeronautics Committee; Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-15

    ... From the Federal Register Online via the Government Publishing Office NATIONAL AERONAUTICS AND SPACE ADMINISTRATION NASA Advisory Council; Aeronautics Committee; Meeting AGENCY: National Aeronautics... Committee Act, Public Law 92-463, as amended, the National Aeronautics and Space Administration announces...

  12. Outcomes of the 2015 World Radiocommunication Conference for Aeronautical Spectrum and Applications

    NASA Technical Reports Server (NTRS)

    Kerczewski, Robert J.; Jonasson, Loftur

    2016-01-01

    At the conclusion of a nearly four year study cycle following the closing of the 2012 World Radiocommunication Conference (WRC-12), the 2015 WRC in November of 2015 considered a number of agenda items and issues relevant to systems and spectrum allocations supporting communications, navigation and surveillance for the operation of civil aviation. Among a number of WRC-15 agenda items and issues, the key agenda items affecting civil aviation included: unmanned aircraft systems use of the Fixed Satellite Service for command and control communications; global flight tracking; new allocations to International Mobile Telecommunications (IMT); and protection of the Fixed Satellite Service to support safe operation of aircraft. A number of other agenda items affecting or potentially affecting civil aviation were also addressed by WRC-15. In this paper we describe the outcomes of WRC-15 for these civil aeronautical-relevant issues. We then outline the civil aviation-related agenda items and issues that will be considered at the upcoming 2019 WRC.

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

    PubMed

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

    2014-01-01

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

  14. Design of high-order HTS dual-band bandpass filters with receiver subsystem for future mobile communication systems

    NASA Astrophysics Data System (ADS)

    Sekiya, N.

    2016-08-01

    We have developed two high-order high-temperature superconducting (HTS) dual-band bandpass filters (BPFs) with a receiver subsystem for future mobile communication systems. They feature stub-loaded hair-pin resonators with two types of microstrip lines between them. One has a six-pole design, and the other has an eight-pole design. Both were designed to operate at 2.15 GHz with a 43-MHz (2%) bandwidth for the lower passband and at 3.50 GHz with a 70-MHz (2%) bandwidth for the upper one. They were fabricated using YBa2Cu3Oy thin film on a CeO2-bufferd r-Al2O3 substrate. The measured results for both filters agree well with the simulated ones. The HTS dual-band BPF receiver subsystem uses a pulse tube cryocooler and a wideband low noise amplifier (LNA). We measured the frequency response of the six-pole dual-band BPF with and without a wideband LNA with a gain of 10 dB. The measured return losses were close.

  15. NASA GRC/Aeronautics Overview

    NASA Technical Reports Server (NTRS)

    Sehra, Arun K.

    2003-01-01

    Twenty-first-century aeropropulsion and power research will enable new transport engine and aircraft systems including: 1) Emerging ultralow noise and emissions with the use of intelligent turbofans; 2) Future distributed vectored propulsion with 24-hour operations and greater community mobility; 3) Research in hybrid combustion and electric propulsion systems leading to silent aircraft with near-zero emissions; and 4) The culmination of these revolutions will deliver an all-electric- powered propulsion system with zero-impact emissions and noise and high-capacity, on-demand operation

  16. Reynolds number influences in aeronautics

    NASA Technical Reports Server (NTRS)

    Bushnell, Dennis M.; Yip, Long P.; Yao, Chung-Sheng; Lin, John C.; Lawing, Pierce L.; Batina, John T.; Hardin, Jay C.; Horvath, Thomas J.; Fenbert, James W.; Domack, Christopher S.

    1993-01-01

    Reynolds number, a measure of the ratio of inertia to viscous forces, is a fundamental similarity parameter for fluid flows and therefore, would be expected to have a major influence in aerodynamics and aeronautics. Reynolds number influences are generally large, but monatomic, for attached laminar (continuum) flow; however, laminar flows are easily separated, inducing even stronger, non-monatomic, Reynolds number sensitivities. Probably the strongest Reynolds number influences occur in connection with transitional flow behavior. Transition can take place over a tremendous Reynolds number range, from the order of 20 x 10(exp 3) for 2-D free shear layers up to the order of 100 x 10(exp 6) for hypersonic boundary layers. This variability in transition behavior is especially important for complex configurations where various vehicle and flow field elements can undergo transition at various Reynolds numbers, causing often surprising changes in aerodynamics characteristics over wide ranges in Reynolds number. This is further compounded by the vast parameterization associated with transition, in that any parameter which influences mean viscous flow development (e.g., pressure gradient, flow curvature, wall temperature, Mach number, sweep, roughness, flow chemistry, shock interactions, etc.), and incident disturbance fields (acoustics, vorticity, particulates, temperature spottiness, even electro static discharges) can alter transition locations to first order. The usual method of dealing with the transition problem is to trip the flow in the generally lower Reynolds number wind tunnel to simulate the flight turbulent behavior. However, this is not wholly satisfactory as it results in incorrectly scaled viscous region thicknesses and cannot be utilized at all for applications such as turbine blades and helicopter rotors, nacelles, leading edge and nose regions, and High Altitude Long Endurance and hypersonic airbreathers where the transitional flow is an innately critical

  17. Communications

    ERIC Educational Resources Information Center

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

    2013-01-01

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

  18. Economic analysis of aeronautical research and technology

    NASA Technical Reports Server (NTRS)

    Gellman, A. J.

    1982-01-01

    The appropriateness of government intervention in the civilian market for aeronautics research and technology (R&T) is examined. The economic rationale for government intervention is examined. The conclusion is that the institutional role played by NASA in civilian aeronautics R&T markets is economically justified.

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

    PubMed

    Miclaus, Simona; Bechet, Paul; Gheorghevici, Marius

    2013-04-01

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

  20. Review of Aeronautical Wind Tunnel Facilities

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The nation's aeronautical wind tunnel facilities constitute a valuable technological resource and make a significant contribution to the global supremacy of U.S. aircraft, both civil and military. At the request of NASA, the National Research Council's Aeronautics and Space Engineering Board organized a commitee to review the state of repair, adequacy, and future needs of major aeronautical wind tunnel facilities in meeting national goals. The comittee identified three main areas where actions are needed to sustain the capability of NASA's aeronautical wind tunnel facilities to support the national aeronautical research and development activities: tunnel maintenance and upgrading, productivity enhancement, and accommodation of new requirements (particularly in hypersonics). Each of these areas are addressed and the committee recommendations for appropriate actions presented.