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1

Public service satellite communications  

NASA Technical Reports Server (NTRS)

It is suggested that the high effective isotropic radiated power provided by high-power satellite transmitters and high-gain antennas could be used in conjunction with economical ground receivers to furnish public services in remote areas of the U.S. Applications to health care, education and public safety are mentioned. A system concept involving a communications satellite operating in the Ku-band (12-GHz down, 14-GHz up) and either 100/30 watt stationary earth terminals with 1-1.8 m antennas or mobile terminals with omnidirectional antennas is presented.

Wolff, E. A.

1978-01-01

2

Satellite communication for public services  

NASA Technical Reports Server (NTRS)

Public service programs using NASA's ATS-6 and CTS satellites are discussed. Examples include the ATS-6 Health and Education Telecommunications experimental program and the use of CTS to enable students in one university to take courses presented at another distant university. Possible applications of satellite communication systems to several areas of public service are described, and economic and political obstacles hindering the implementation of these programs are considered. It is suggested that a federally sponsored program demonstrating the utility of satellites accomodating a large number of small terminals is needed to encourage commercial satellite operations.

Cooper, R. S.; Redisch, W. N.

1977-01-01

3

A public service communications satellite user brochure  

NASA Technical Reports Server (NTRS)

The capabilities of a proposed communications satellite that would be devoted to experiments and demonstrations of various public services is described. A Public Service Communications Satellite study was undertaken at the NASA Goddard Space Flight Center (GSFC) to define the problems and opportunities of a renewed NASA role and the form such NASA involvement should take. The concept that has evolved has resulted from careful consideration of experiments that were already undertaken on existing satellites.

1977-01-01

4

Communication Satellites: Experimental & Operational, Commercial & Public Service.  

ERIC Educational Resources Information Center

The title reflects the first and major article in an issue of this newsletter devoted entirely to communication satellites. This series of articles on the potential and applications of communication satellites in development projects is concerned with their development for commercial and public service, development in the Pacific region, SPACECOM…

Development Communication Report, 1979

1979-01-01

5

Public Service Communications Satellite User Requirements Workshop  

NASA Technical Reports Server (NTRS)

Information on user requirements for public service communications was acquired to provide the basis of a study to determine the optimum satellite system to satisfy user requirements. The concept for such a system is described: Topics discussed included requirements for data and message services, elementary and secondary education, extension and continuing education, environmental communications, library services, medical education, medical services, public broadcasting, public safety, religious applications, state and local communications, and voluntary services. Information was also obtained on procedures to follow to make the transfer to commercial services.

Wolff, E. A.

1977-01-01

6

Servicing communication satellites in geostationary orbit  

NASA Technical Reports Server (NTRS)

The econmic benefits of a LEO space station are quantified by identifying alternative operating scenarios utilizing the space station's transportation facilities and assembly and repair facilities. Particular consideration is given to the analysis of the impact of on-orbit assembly and servicing on a typical communications satellite is analyzed. The results of this study show that on-orbit servicing can increase the internal rate of return by as much as 30 percent.

Russell, Paul K.; Price, Kent M.

1990-01-01

7

Mobile satellite communications in the Forest Service  

NASA Astrophysics Data System (ADS)

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

Warren, John R.

1988-05-01

8

Mobile satellite communications in the Forest Service  

NASA Technical Reports Server (NTRS)

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

Warren, John R.

1988-01-01

9

USDA Forest Service mobile satellite communications applications  

NASA Technical Reports Server (NTRS)

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

Warren, John R.

1990-01-01

10

Taking Advantage of Opportunities for Commercial Satellite Communications Services.  

National Technical Information Service (NTIS)

The Department of Defense (DoD) relies upon the United States commercial satellite private sector to provide about 40% of its satellite communication services at a cost of roughly $640 million per year. These commercial satellite service providers often a...

2013-01-01

11

Mobile satellite service communications tests using a NASA satellite  

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

12

LEOPACK The integrated services communications system based on LEO satellites  

NASA Astrophysics Data System (ADS)

LEOPACK is yet another LEO satellite project which provides global integrated services for 'business' communications. It utilizes packet rather then circuit switching in both terrestrial and satellite chains as well as cellular approach for frequencies use. Original multiple access protocols and decentralized network control make it possible to organize regionally or logically independent and world-wide networks. Relatively small number of satellites (28) provides virtually global network coverage.

Negoda, A.; Bunin, S.; Bushuev, E.; Dranovsky, V.

13

New technology and Maritime Satellite communication services  

NASA Astrophysics Data System (ADS)

The INMARSAT (International Maritime Satellite Organization) system is considered in terms of future technology applications in the development of low cost ship earth stations for the large numbers of smaller ships with low traffic demands, while also catering to large-volume users with multi-channel capacity terminals. Antenna stabilization and other microprocessor control system functions are reviewed. A significant means of potential cost reduction of ship earth stations is to replace stabilized 1.2 m antennae by smaller wide beam antennae with static stabilization. The recent development of a prototype Multibeam Array Model is given as one approach to producing greater satellite capacity through the use of higher gain spacecraft antennae, and to overcoming the resultant narrower beamwidth problem by using a number of spot beams to give full ocean coverage. Plans for the utilization of satellites for a Future Global Maritime Distress and Safety system are outlined.

Wooster, C. B.

1984-02-01

14

Emerging markets for satellite data communications in the public service  

NASA Technical Reports Server (NTRS)

The paper discusses some of the current and potential markets for satellite data communications as projected by the Public Service Satellite Consortium (PSSC). Organizations in the public service sector are divided into three categories, depending on their expected benefits and organizational changes due to increased satellite telecommunications use: A - modest institutional adjustments are necessary and significant productivity gains are likely; B - institutional requirements picture is promising, but more information is needed to assess benefits and risk; and C - major institutional adjustments are needed, risks are high but possible benefits are high. These criteria are applied to the U.S. health care system, continuing education, equipment maintenance, libraries, environmental monitoring, and other potential markets. The potential revenues are seen to be significant, but what is needed is a cooperative effort by common carriers and major public service institutions to aggregate the market.

Potter, J. G.

1978-01-01

15

Planning satellite communication services and spectrum-orbit utilization  

NASA Technical Reports Server (NTRS)

The relationship between approaches to planning satellite communication services and spectrum-orbit utilization is considered, with emphasis on the fixed-satellite and the broadcasting-satellite services. It is noted that there are several possible approaches to planning space services, differing principally in the rigidity with which technical parameters are prescribed, in the time for which a plan remains in force, and in the procedures adopted for implementation and modifications. With some planning approaches, spectrum-orbit utilization is fixed at the time the plan is made. Others provide for greater flexibility by making it possible to postpone some decisions on technical parameters. In addition, the two political questions of what is equitable access and how it can be guaranteed in practice play an important role.

Sawitz, P. H.

1982-01-01

16

Repeater in the sky. [public service communications satellite program  

NASA Technical Reports Server (NTRS)

The Public Service Communications Satellite (PSCS) program is intended to develop and demonstrate a space system aimed at stimulating future commercial markets in fixed and mobile applications. The services are envisioned for rural areas, regions beyond access to terrestrial systems, or for continuous cross-country applications. The system incorporates a UHF repeater for mobile voice and data experiments; 8 MHz of spectrum is specified for serving 70 channels. This paper describes the PSCS program and discusses some demonstration experiments. A future concept based on large structure multibeam antennas is also discussed.

Cote, C. E.; Brown, J. P.

1977-01-01

17

Developing satellite communications for public service: Prospects in four service areas  

NASA Technical Reports Server (NTRS)

The Public Service Satellite Consortium evaluated prospects for satellite telecommunications in four areas of the public service: the U.S. health care system, elementary and secondary education, American libraries, and that sector of the public service which is concerned with the provision of continuing education to health professionals. Three important conclusions were reached. First, throughout the public service there are three recurring needs: improved access, cost containment, and maintenance of quality. Appropriate application of communication satellite systems could ameliorate each of these concerns. Second, there appears to be an enormous latent demand for data communication services throughout the public service. The potential demand in 1982 to support requirements in hospital administration, library services and other information-retrieval activities, equipment maintenance, and environmental monitoring may be in excess of $300 million a year. Third, administrative applications of data communication networks show particular promise, especially in rural areas.

1977-01-01

18

Satellite communications service: Leased or owned transponders on domestic, regional, or global satellite systems?  

NASA Astrophysics Data System (ADS)

Today when we discuss satellite systems in a worldwide arena, the focus is no longer on just providing services to individual national markets. A truly global perspective means looking past the artificial restrictions of geographic boundaries and recognizing one large international marketplace. Therefore, in the realm of worldwide space communications, systems limited solely to the provision of domestic or even regional services may no longer be viable. Nonetheless, the construction and operation of a dedicated satellite system is a financially and technically risky investment. Satellite systems have high fixed costs and limited lives. Unless users are committed prior to launch, there is the financial risk of having to carry transponders as in-orbit inventory, as well as the risk that the transponder design will not meet customer demands. Several other aspects of global satellite communication systems are discussed. These other aspects include the following: global markets, technology access, start-up costs, carrying costs, and risk.

Daffner, Gregg

19

Technical design and service aspects of digital mobile satellite communication systems  

Microsoft Academic Search

The key technical elements in designing digital mobile satellite communication systems are identified, and tradeoff studies on the transmission parameters of the satellite link, which were based on experience with an experimental system and the results of field trials, on digital maritime and aeronautical satellite communication systems, are described. The future evolution of the various new communication services to be

Yutaka YASUDA; Masayoshi OHASHI; Fumiaki SUGAYA; Yasuo HIRATA

1988-01-01

20

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

NASA Technical Reports Server (NTRS)

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

1976-01-01

21

Satellite communications experiment for the Ontario air ambulance service  

NASA Astrophysics Data System (ADS)

A satellite communications experiment was conducted to develop a reliable voice communications system between paramedics and doctors at certain larger medical centers. The experiment used INMARSAT's Atlantic Ocean Region satellite which provides coverage to the western border of Ontario. Forward downlink power from the satellite is in great demand, so two highly power-efficient modulation schemes were chosen for evaluation during the experiment. These were amplitude-companded single-sideband (ACSSB) and linear predictive coding in conjunction with DMSK modulation. Good performance with a signal to noise ratio of about 10 dB was demonstrated from many parts of the province with the evevation angle to the satellite ranging from five to twenty degrees and with the aircraft both in-flight and on the runway.

Butterworth, John S.

1988-05-01

22

The application of mobile satellite services to emergency response communications  

NASA Technical Reports Server (NTRS)

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

Freibaum, J.

1980-01-01

23

Satellite provided fixed communications services: A forecast of potential domestic demand through the year 2000: Volume 2: Main test  

Microsoft Academic Search

Potential satellite-provided fixed communications services, baseline forecasts, net long haul forecasts, cost analysis, net addressable forecasts, capacity requirements, and satellite system market development are considered.

D. Kratochvil; J. Bowyer; C. Bhushan; K. Steinnagel; D. Kaushal; G. Al-Kinani

1983-01-01

24

Satellite provided fixed communications services: A forecast of potential domestic demand through the year 2000: Volume 2: Main text  

NASA Technical Reports Server (NTRS)

Potential satellite-provided fixed communications services, baseline forecasts, net long haul forecasts, cost analysis, net addressable forecasts, capacity requirements, and satellite system market development are considered.

Kratochvil, D.; Bowyer, J.; Bhushan, C.; Steinnagel, K.; Kaushal, D.; Al-Kinani, G.

1983-01-01

25

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

NASA Technical Reports Server (NTRS)

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

Horstein, M.; Barnett, R.

1981-01-01

26

Preliminary benefits study for a public service communications satellite system: Task order 2  

NASA Technical Reports Server (NTRS)

The economic and social benefits to accrue from an operational public service communications satellite system are estimated for the following applications: teleradiology, emergency medical services, teleconferencing for both civilian and defense agencies, data transfer, remote cardiac monitoring, teleconsultation, continuing education for professionals, and severe storm warning. The potential impact of improved communication on the cost and quality of services are assessed for various agencies, professions, and industries.

1978-01-01

27

Remarks by Dr. James C. Fletcher at Conference on Satellite Communication and Public Service  

NASA Technical Reports Server (NTRS)

The present status of communications satellites, together with the future goals and technology developments in use of public service, is assessed. Improvements in design during the last decade considerably cut the cost of their development and launching, and the systems carry information to millions of people on earth. The space shuttles will change the rules in design and make it possible for communications satellites to have multiple frequencies operating at high power.

Fletcher, J. C.

1976-01-01

28

Use of communications. [satellite communication  

NASA Technical Reports Server (NTRS)

Progress in the field of satellite communications is reviewed, and useful services which may be provided by future satellite communications systems are considered. Recommendations are made with regard to mobile communications for use on land and at sea, position determination, mineral and energy exploration, the possibility of using electronic means to assist in main delivery, education and health-care experiments, and the use of satellite telecommunications to enhance the quality of life in rural areas by making available a full range of educational and entertainment programs. The needs of the amateur radio community are also considered.

1975-01-01

29

The Role of Satellites in Personal Communication Services  

Microsoft Academic Search

This paper aims at providing a complete analysis of the issues relevant to satellite systems in the perspective of the third generation of mobile systems. The analysis considers, on the one hand, the possible satellite system evolutionary paths and, on the other hand, the satellite system requirements related to technological issues. As regards the satellite evolutionary paths, the paper provides

Fulvio Ananasso; Francesco Delli Priscoli

1995-01-01

30

Optimization of orbital assignment and specification of service areas in satellite communications  

NASA Technical Reports Server (NTRS)

The mathematical nature of the orbital and frequency assignment problem for communications satellites is explored, and it is shown that choosing the correct permutations of the orbit locations and frequency assignments is an important step in arriving at values which satisfy the signal-quality requirements. Two methods are proposed to achieve better spectrum/orbit utilization. The first, called the delta S concept, leads to orbital assignment solutions via either mixed-integer or restricted basis entry linear programming techniques; the method guarantees good single-entry carrier-to-interference ratio results. In the second, a basis for specifying service areas is proposed for the Fixed Satellite Service. It is suggested that service areas should be specified according to the communications-demand density in conjunction with the delta S concept in order to enable the system planner to specify more satellites and provide more communications supply.

Wang, Cou-Way; Levis, Curt A.; Buyukdura, O. Merih

1987-01-01

31

An approach to effective UHF (S/L band) data communications for satellite Personal Communication Service (PCS)  

NASA Astrophysics Data System (ADS)

Reliable signaling information transfer is fundamental in supporting the needs of data communication PCS via LMS (Land Mobile Service) SSs (satellite systems). The needs of the system designer can be satisfied only through the collection of media information that can be brought to bear on the pertinent design issues. We at ISI hope to continue our dialogue with fading media experts to address the unique data communications needs of PCS via LMS SSs.

Hayase, Joshua Y.

1995-08-01

32

Telecom 1 - A national communication satellite for domestic and business services  

NASA Astrophysics Data System (ADS)

The French Telecom 1 satellite telecommunications project and the services to be provided by it are surveyed. Telecom 1 will comprise operational and spare satellites located in GEO at 4 and 7 deg W and operating in the 14/12 and 6/4-GHz bands, permanent receive-transmit stations for business data and telephone links, and both permanent receive-only and portable transmit-only stations for video-transmission services. The satellite communications payload includes six 36-MHz 20-W TWT transponders for either video or data transmission at 14/12 GHz and four 6/4-GHz transponders for telephone and video service to the Caribbean and Indian Ocean departments. A demand-assignment TDMA system provides data transmission at 2.4 kbit/s to 2 Mbit/s with nonpermanent links and variable network structure.

Lombard, D.; Rancy, F.; Rouffet, D.

33

Evolution of the NOAA National Weather Service Satellite Broadcast Network (SBN) to Europe's DVB-S satellite communications technology standard  

NASA Astrophysics Data System (ADS)

The National Oceanic and Atmospheric Administration's (NOAA) National Weather Service (NWS) uses a commercial Satellite Broadcast Network (SBN) to distribute weather data to the NWS AWIPS workstations and National Centers and to NWS Family of Service Users. Advances in science and technology from NOAA's observing systems, such as remote sensing satellites and NEXRAD radars, and advances in Numeric Weather Prediction have greatly increased the volume of data to be transmitted via the SBN. The NOAA-NWS SBN Evolution Program did a trade study resulting in the selection of Europe's DVB-S communication protocol as the basis for enabling a significant increase in the SBN capacity. The Digital Video Broadcast (DVB) group, started to develop digital TV for Europe through satellite broadcasting, has become the current standard for defining technology for satellite broadcasting of digital data for much of the world. NOAA-NWS implemented the DVB-S with inexpensive, Commercial Off The Shelf receiving equipment. The modernized NOAA-NWS SBN meets current performance goals and provides the basis for continued future expansion with no increase in current communication costs. This paper discusses aspects of the NOAA-NWS decision and the migration to the DVB-S standard for its commercial satellite broadcasts of observations and Numerical Weather Prediction data.

Cragg, Phil; Brockman, William E.

2006-09-01

34

The plan for the economic evaluation of the Public Service Communication Satellite system  

NASA Technical Reports Server (NTRS)

A total plan for the economic evaluation of the PSCS public service communication satellite program within domestic markets is presented. It extends from the present through the planning, performance and evaluation of economic experiments following the launch of the PSCS, and includes the consideration of how the results of these experiments impact the transfer from demonstration to operations. The implementation of this plan will provide NASA with information needed to understand and manage the economic and social impacts of the PSCS program.

1977-01-01

35

The plan for the economic evaluation of the public service communication satellite system  

NASA Technical Reports Server (NTRS)

A plan for the economic evaluation of the Public Service Communications Satellite (PSCS) within domestic markets is presented. It extends through the planning, performance and evaluation of economic experiments following the launch of the PSCS in 1982, and includes the consideration of how the results of these experiments impact the transfer from demonstration to operations. The implementation of this plan will provide information needed to understand and manage the economic and social impacts of the PSCS program.

1977-01-01

36

Study of spread spectrum multiple access systems for satellite communications with overlay on current services  

NASA Technical Reports Server (NTRS)

The feasibility of using spread spectrum techniques to provide a low-cost multiple access system for a very large number of low data terminals was investigated. Two applications of spread spectrum technology to very small aperture terminal (VSAT) satellite communication networks are presented. Two spread spectrum multiple access systems which use a form of noncoherent M-ary FSK (MFSK) as the primary modulation are described and the throughput analyzed. The analysis considers such factors as satellite power constraints and adjacent satellite interference. Also considered is the effect of on-board processing on the multiple access efficiency and the feasibility of overlaying low data rate spread spectrum signals on existing satellite traffic as a form of frequency reuse is investigated. The use of chirp is examined for spread spectrum communications. In a chirp communication system, each data bit is converted into one or more up or down sweeps of frequency, which spread the RF energy across a broad range of frequencies. Several different forms of chirp communication systems are considered, and a multiple-chirp coded system is proposed for overlay service. The mutual interference problem is examined in detail and a performance analysis undertaken for the case of a chirp data channel overlaid on a video channel.

Ha, Tri T.; Pratt, Timothy

1989-01-01

37

Wide-area technologies and services in the Trans-Pacific High Data Rate (HDR) satellite communications experiments  

NASA Technical Reports Server (NTRS)

This paper describes the technologies and services used in the experiments and demonstrations using the Trans-Pacific high data rate satellite communications infrastructure, and how the environment tasked protocol adaptability, scalability, efficiency, interoperability, and robustness.

Hsu, E.; Hung, C.; Kadowaki, N.; Yoshimura, N.; Takahashi, T.; Shopbell, P.; Walker, G.; Wellnitz, D.; Gary, P.; Clark, G.; Yoshikawa, M.; desJardins, R.; Gill, M.; Tatsumi, H.

2000-01-01

38

Satellite Communications for U.S. Schools; A Proposed Public Service Offering by Private Business.  

ERIC Educational Resources Information Center

The Federal Communications Commission has asked that companies seeking authorization to construct and operate communications satellite facilities for multi-purpose commercial uses in the United States give consideration to the communications needs of schools. In response to this request, MCI Lockheed Satellite Corporation proposes a low-cost…

Krause, Lloyd I.

39

Digital communications by satellite  

Microsoft Academic Search

Topics in digital satellite communications are treated extensively for a readership of students or communications system designers acquainted with communications theory fundamentals and random processes. Major parts of the book are: signal quantizing and multiplexing; satellite communications; modulation and coding in distorted channels; worldwide timing by satellite relay. Some specific topics treated include: PCM quantizing, sampling of nonbandlimited signals, delta

J. J. Spilker Jr.

1977-01-01

40

Communications technology satellite  

NASA Technical Reports Server (NTRS)

A description of the Communications Technology Satellite (CTS), its planned orbit, its experiments, and associated ground facilities was given. The communication experiments, to be carried out by a variety of groups in both the United States and Canada, include tele-education, tele-medicine, community interaction, data communications and broadcasting. A historical summary of communications satellite development was also included.

1976-01-01

41

Advanced Communications Technology Satellite (ACTS)  

NASA Technical Reports Server (NTRS)

The NASA Advanced Communications Technology Satellite (ACTS) was conceived to help maintain U.S. leadership in the world's communications-satellite market. This experimental satellite is expected to be launched by NASA in 1992 and to furnish the technology necessary for establishing very small aperture terminal digital networks which provide on-demand full-mesh connectivity, and 1.544-MBPS services with only a single hop. Utilizing on-board switching and processing, each individual voice or data circuit can be separately routed to any location in the network. This paper provides an overview of the ACTS and discusses the value of the technology for future communications systems.

Gedney, Richard T.; Schertler, Ronald J.

1989-01-01

42

Maritime satellite communications  

NASA Astrophysics Data System (ADS)

Principles underlying the design and operation of maritime satellite communications systems are reviewed, with reference to Inmarsat and Sarsat. Particular attention is given to the design of search and rescue systems, the development of the onboard equipment, and the characteristics of coastal and shipboard earth stations. Finally, the organization of maritime satellite communications systems is discussed, and questions of system efficiency are examined.

Novik, Leonid I.; Morozov, Igor'd.; Solov'ev, Vladimir I.

43

Digital satellite communications  

NASA Astrophysics Data System (ADS)

The use of satellite communications in point-to-multipoint transmission of data is studied. The theory, systems, and equipment for satellite communications are described. The topics of satellite orbits, satellite construction, earth station equipment, and the analysis of the satellite link are discussed. Different types of digital modulation for carrier transmission, and techniques for enhancing the transmission capacity, such as digital speech interpolation and demand assignment, are examined. Techniques and equipment for performing the multiple access-broadcasting functions including FDMA, TDMA, DAMA, CDMA, and random access are considered.

Ha, T. T.

1986-06-01

44

78 FR 19172 - Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit...  

Federal Register 2010, 2011, 2012, 2013

...CFR Parts 2 and 25 [IB Docket No. 12-376; FCC 12-161] Earth Stations Aboard Aircraft Communicating with Fixed-Satellite...Register of March 8, 2013. The document proposed rules for Earth Stations Aboard Aircraft. FOR FURTHER INFORMATION...

2013-03-29

45

System considerations, projected requirements and applications for aeronautical mobile satellite communications for air traffic services  

NASA Technical Reports Server (NTRS)

The projected application and requirements in the near term (to 1995) and far term (to 2010) for aeronautical mobile services supporting air traffic control operations are addressed. The implications of these requirements on spectrum needs, and the resulting effects on the satellite design and operation are discussed. The U.S. is working with international standards and regulatory organizations to develop the necessary aviation standards, signalling protocols, and implementation methods. In the provision of aeronautical safety services, a number of critical issues were identified, including system reliability and availability, access time, channel restoration time, interoperability, pre-emption techniques, and the system network interfaces. Means for accomplishing these critical services in the aeronautical mobile satellite service (AMSS), and the various activities relating to the future provision of aeronautical safety services are addressed.

Mcdonald, K. D.; Miller, C. M.; Scales, W. C.; Dement, D. K.

1990-01-01

46

47 CFR 25.279 - Inter-satellite service.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 false Inter-satellite service. 25.279 Section 25...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Operations § 25.279 Inter-satellite service. (a) Any satellite...

2013-10-01

47

47 CFR 25.279 - Inter-satellite service.  

Code of Federal Regulations, 2010 CFR

... 2009-10-01 false Inter-satellite service. 25.279 Section 25...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Operations § 25.279 Inter-satellite service. (a) Any satellite...

2009-10-01

48

Demand for satellite-provided domestic communications services up to the year 2000  

NASA Technical Reports Server (NTRS)

Three fixed service telecommunications demand assessment studies were completed for NASA by The Western Union Telegraph Company and the U.S. Telephone and Telegraph Corporation. They provided forecasts of the total U.S. domestic demand, from 1980 to the year 2000, for voice, data, and video services. That portion that is technically and economically suitable for transmission by satellite systems, both large trunking systems and customer premises services (CPS) systems was also estimated. In order to provide a single set of forecasts a NASA synthesis of the above studies was conducted. The services, associated forecast techniques, and data bases employed by both contractors were examined, those elements of each judged to be the most appropriate were selected, and new forecasts were made. The demand for voice, data, and video services was first forecast in fundamental units of call-seconds, bits/year, and channels, respectively. Transmission technology characteristics and capabilities were then forecast, and the fundamental demand converted to an equivalent transmission capacity. The potential demand for satellite-provided services was found to grow by a factor of 6, from 400 to 2400 equivalent 36 MHz satellite transponders over the 20-year period. About 80 percent of this was found to be more appropriate for trunking systems and 20 percent CPS.

Stevenson, S.; Poley, W.; Lekan, J.; Salzman, J. A.

1984-01-01

49

Demand for satellite-provided domestic communications services up to the year 2000  

NASA Astrophysics Data System (ADS)

Three fixed service telecommunications demand assessment studies were completed for NASA by The Western Union Telegraph Company and the U.S. Telephone and Telegraph Corporation. They provided forecasts of the total U.S. domestic demand, from 1980 to the year 2000, for voice, data, and video services. That portion that is technically and economically suitable for transmission by satellite systems, both large trunking systems and customer premises services (CPS) systems was also estimated. In order to provide a single set of forecasts a NASA synthesis of the above studies was conducted. The services, associated forecast techniques, and data bases employed by both contractors were examined, those elements of each judged to be the most appropriate were selected, and new forecasts were made. The demand for voice, data, and video services was first forecast in fundamental units of call-seconds, bits/year, and channels, respectively. Transmission technology characteristics and capabilities were then forecast, and the fundamental demand converted to an equivalent transmission capacity. The potential demand for satellite-provided services was found to grow by a factor of 6, from 400 to 2400 equivalent 36 MHz satellite transponders over the 20-year period. About 80 percent of this was found to be more appropriate for trunking systems and 20 percent CPS.

Stevenson, S.; Poley, W.; Lekan, J.; Salzman, J. A.

1984-11-01

50

Remote Psychiatric and Psychological Services via the Communications Technology Satellite (CTS).  

ERIC Educational Resources Information Center

To provide remote psychiatric services to a population in Moose Factory, Ontario, via satellite, digital data links will be used to provide 24-hour access to the psychiatric medical file system and the psychiatric patient register at University Hospital, London, Ontario, and to permit scoring and interpretation of standard psychological tests. The…

Covvey, H. Dominic; And Others

51

Results of thin-route satellite communication system analyses including estimated service costs  

NASA Technical Reports Server (NTRS)

Ways for determining optimum satellite and terrestrial system architectures and parameters for providing the most economical telephone service to remote areas of the U.S. are explored. Several configurations for an isolated rural telephone system, covering all the states plus Alaska, employing satellites is considered. Both direct-to-the-user and community-type of systems are evaluated using UHF and Ku-band RF equipment for the rural/satellite links. The effect of multiple spot beams, outage, signal quality, modulation method, satellite accessing, forward error correction, and the number of users are also evaluated. The total cost for a 5-minute call from an isolated rural user to a TELCO user was shown to be as low as $1.30 for a system with 1.8 X 10 to the sixth rural users.

Wright, D. L.

1979-01-01

52

Advanced Communications Technology Satellite (ACTS)  

NASA Technical Reports Server (NTRS)

The NASA Advanced Communications Technology Satellite (ACTS) provides high risk technologies having the potential to dramatically enhance the capabilities of the satellite communications industry. This experimental satellite, which will be launched by NASA in 1993, will furnish the technology necessary for providing a range of services. Utilizing the ACTS very-high-gain-hopping spot-beam antennas with on-board routing and processing, Very Small Aperture Terminal (VSAT) digital networks which provide on-demand, full-mesh-convectivity 1.544-MBPS services with only a single hop can be established. The high-gain spot-beam antenna at Ka-band permits wide area, flexible networks providing high data rate services between modest-size earth terminals.

Plecity, Mark S.; Nall, Mark E.

1991-01-01

53

Signals from Communications Satellites.  

ERIC Educational Resources Information Center

Discusses the Doppler effect for relative motion between a source of waves and an observer and the orbital dynamics of communications satellites. Presents preliminary calculations of the satellite's altitude and linear velocity using only the concepts of the Doppler shift and the mechanics of motion in a circular path. (JRH)

Thomsen, Volker

1996-01-01

54

Satellite Communications Using Commercial Protocols  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

55

International communications via satellite  

NASA Astrophysics Data System (ADS)

The evolution of communications satellite systems is traced in terms of technical capabilities and technological advances. The Communications Act of 1962 led to the establishment of INTELSAT on an international basis in 1964. The original 19 signatory nations has grown to over 100, and over 800 ground relay stations have been built. The INTELSAT system comprises spacecraft over the Atlantic, Pacific, and Indian Oceans and handles 2/3 of the world's international electronic communications and all transoceanic television. The 1965 Early Bird satellite had a 240 two-way telephone link capacity and weighed 38 kg, while the Intelsat V satellites, of which there will be nine, have increased the capacity to 20,000 voice circuits and Intelsat VI will double the number by 1993. Increasing demand for satellite communications links is driving the design and development of space platforms for multiple missions of communications, meteorological studies, and on-board switching and data processing in excess of current multiple satellite systems.

McLucas, J. L.

56

Upcoming communications satellites  

NASA Astrophysics Data System (ADS)

A new series of international and business communications satellites will be launched by ‘workhorse’ rocket systems, including updated Delta and Atlas/Centaur rockets, over the next few years. There is, of course, a ‘long-shot’ option that the space shuttle, as originally conceived, will be used to place the satellites in orbit, but no one is willing to bet right now that the shuttle will be functional and operational in time. Instead, the U.S. will employ updated versions of 15-20-year-old rockets to launch a series of satellites with names like ‘INTELSAT,’ ‘INSAT,’ ‘Palapa,’ and ‘SBS’ into geosynchronous orbits.INTELSAT V is the first of a new generation of international telecommunications satellites sponsored by the 105-nation International Telecommunications Satellite Organization (INTELSAT), headquartered in Washington, D.C. The satellite, which weighs 1,928 kg at launch, has almost double the communications capability of early satellites in the INTELSAT series. It is positioned in geosynchronous orbit over the Atlantic Ocean so as to provide communications between North America and Europe.

Bell, Peter M.

57

Domestic satellite communications overview  

NASA Astrophysics Data System (ADS)

The current status and future planning of satellite systems for intranational communication are examined in a summary of presentations given at the CCIR international seminar on domestic satellite communications held in Shanghai in October 1983. Topics discussed include operational and planned systems in Australia, Japan, the U.S., India, China, France, Brazil, Italy, Thailand, and the European region; development and planning by NASA and Intelsat; systems for rural areas or light traffic; modulation and multiple access; antennas, propagation, and interference; geostationary orbits; and economics, planning, and implementation.

Nickelson, R. L.

1984-09-01

58

Future communications satellite applications  

NASA Technical Reports Server (NTRS)

The point of view of the research is made through the use of viewgraphs. It is suggested that future communications satellite applications will be made through switched point to point narrowband communications. Some characteristics of which are as follows: small/low cost terminals; single hop communications; voice compatible; full mesh networking; ISDN compatible; and possible limited use of full motion video. Some target applications are as follows: voice/data networks between plants and offices in a corporation; data base networking for commercial and science users; and cellular radio internodal voice/data networking.

Bagwell, James W.

1992-01-01

59

Overview of commercial satellite communications  

NASA Astrophysics Data System (ADS)

A brief history of communications satellites is presented, taking into account the launching of Sputnik 1 in October 1957, the Explorer 1 in January of 1958, the launch of the Score as the world's first active communications satellite in December 1958, the Communications Satellite Act in 1962, and the launch of 'Early Bird' in 1964. The Intelsat satellites are considered along with maritime satellite communications, the U.S. domestic satellite systems, Alaskan satellite communications, cable television, broadcast TV stations, print media, the hotel/motel industry as a large market for satellite communications terminals, the opening of a minicable and satellite master antenna TV market for TV receive-only systems, and business telecommunications earth terminals. Attention is also given to future directions regarding satellite positions, the concept of 'video-plus', and direct broadcast satellites.

Beakley, G. W.

1984-07-01

60

Land-mobile satellite communication system  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

61

Odyssey, an optimized personal communications satellite system  

NASA Astrophysics Data System (ADS)

Personal communications places severe demands on service providers and transmission facilities. Customers are not satisfied with the current levels of service and want improvements. Among the characteristics that users seek are: lower service rates, hand held convenience, acceptable time delays, ubiquitous service, high availability, reliability, and high quality. The space industry is developing commercial space systems for providing mobile communications to personal telephones. Provision of land mobile satellite service is fundamentally different from the fixed satellite service provided by geostationary satellites. In fixed service, the earth based antennas can depend on a clear path from user to satellite. Mobile users in a terrestrial environment commonly encounter blockage due to vegetation, terrain or buildings. Consequently, high elevation angles are of premium value. TRW studied the issues and concluded that a Medium Earth Orbit constellation is the best solution for Personal Communications Satellite Service. TRW has developed Odyssey, which uses twelve satellites in medium altitude orbit to provide personal communications satellite service. The Odyssey communications system projects a multibeam antenna pattern to the Earth. The attitude control system orients the satellites to ensure constant coverage of land mass and coastal areas. Pointing can be reprogrammed by ground control to ensure optimized coverage of the desired service areas. The payload architecture features non-processing, "bent pipe" transponders and matrix amplifiers to ensure dynamic power delivery to high demand areas. Circuit capacity is 3000 circuits per satellite. Each satellite weighs 1917 kg (4226 pounds) at launch and the solar arrays provide 3126 Watts of power. Satellites are launched in pairs on Ariane, Atlas, or other vehicles. Each satellite is placed in a circular orbit at an altitude of 10,354 km. There are three orbit planes inclined at 55° to the equatorial plane. Deployment of the satellites permits phased introduction of service. After only three launches, in which two satellites are launched into each plane, continuous service can be provided to most of the world. After three more launches for a total of 12 satellites, service can be expanded to all populated regions of the Earth with path diversity to most regions. The Odyssey system is superior to both geostationary satellites and low earth orbiting satellites. Odyssey provides many benefits to the end user which are described in the paper. These include: low cost, convenience, high availability, reliability, and acceptable time delay. Odyssey exhibits benefits for telecommunications operators: simple operations, incremental, phased startup, long space segment life-time, high profitability, dynamic flexibility for adjustment and short time to market. Since submission of an FCC application in 1991, TRW has continued to explore ways to further improve the Odyssey approach by expanding coverage to the entire world and reducing the initial investment while maintaining high quality service.

Rusch, Roger J.

62

Low Earth orbit communications satellite  

NASA Technical Reports Server (NTRS)

A current thrust in satellite communication systems considers a low-Earth orbiting constellations of satellites for continuous global coverage. Conceptual design studies have been done at the time of this design project by LORAL Aerospace Corporation under the program name GLOBALSTAR and by Motorola under their IRIDIUM program. This design project concentrates on the spacecraft design of the GLOBALSTAR low-Earth orbiting communication system. Overview information on the program was gained through the Federal Communications Commission licensing request. The GLOBALSTAR system consists of 48 operational satellites positioned in a Walker Delta pattern providing global coverage and redundancy. The operational orbit is 1389 km (750 nmi) altitude with eight planes of six satellites each. The orbital planes are spaced 45 deg., and the spacecraft are separated by 60 deg. within the plane. A Delta 2 launch vehicle is used to carry six spacecraft for orbit establishment. Once in orbit, the spacecraft will utilize code-division multiple access (spread spectrum modulation) for digital relay, voice, and radio determination satellite services (RDSS) yielding position determination with accuracy up to 200 meters.

Moroney, D.; Lashbrook, D.; Mckibben, B.; Gardener, N.; Rivers, T.; Nottingham, G.; Golden, B.; Barfield, B.; Bruening, J.; Wood, D.

1992-01-01

63

Technical requirements for communications satellite  

NASA Astrophysics Data System (ADS)

This paper presents 15 factors that should be considered as technical requirements for communications satellite. Relations between these factors are described with examples from a domestic business communications satellite.

Min, Shiquan

1990-02-01

64

Satellite Services Workshop, Volume 1  

NASA Technical Reports Server (NTRS)

Key issues associated with the orbital servicing of satellites are examined including servicing spacecraft and equipment, servicing operations, economics, satellite design, docking and berthing, and fluid management.

1982-01-01

65

Satellite communications in the next decade  

NASA Astrophysics Data System (ADS)

This paper describes a view of satellite communications missions in the 1990s. It is forecasted not only that future needs of satellite communication/broadcast services will grow, but also that requirements will become more diverse. Another aspect of future services can be the 'personalization' of satellite communications. In this paper, 37 representative future missions for provision of communication/broadcast services are surveyed. The link budgets for each mission are calculated using reasonable assumptions for both satellite antenna size and frequency band used. As a result, an illustration clarifying the diversification in technology requirements for future missions are obtained, which shows the relationship between scale of earth station, frequency and transmission rate. Finally some candidate missions for the early 1990s communication satellite services are postulated. Among the candidate missions, two missions are selected and discussed briefly, according to the results of preliminary studies: a personal communication system using the satellite, and a satellite broadcast service system in the Asian and Oceanian regions.

Iida, T.; Shimoseko, S.; Iwasaki, K.; Shimada, M.

1985-03-01

66

47 CFR 25.225 - Geographic Service Requirements for 17/24 GHz Broadcasting Satellite Service.  

Code of Federal Regulations, 2013 CFR

...Requirements for 17/24 GHz Broadcasting Satellite Service. 25.225 Section 25.225...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards...Requirements for 17/24 GHz Broadcasting Satellite Service. (a) Each...

2013-10-01

67

76 FR 14297 - The Establishment of Policies and Service Rules for the Broadcasting-Satellite Service  

Federal Register 2010, 2011, 2012, 2013

...Service Rules for the Broadcasting-Satellite Service AGENCY: Federal Communications...adopted for the 17/24 GHz Broadcasting-Satellite Service (BSS). Specifically, we decline...INFORMATION CONTACT: Andrea Kelly, Satellite Division, International Bureau,...

2011-03-16

68

Activities of Canadian Satellite Communications, Inc.  

NASA Astrophysics Data System (ADS)

Canadian Satellite Communications (Cancom) has as its core business the provision of television and radio signals to cable systems in Canada, with the objective of making affordable broadcast signals available to remote and/or small communities. Cancom also provides direct-to-home services to backyard receiving dishes, as well as satellite digital data business communications services, satellite business television, and satellite network services. Its business communication services range from satellite links for big-city businesses with small branch operations located far from major centers, to a mobile messaging and tracking system for the trucking industry. Revenues in 1992 totalled $48,212,000 and net income was just over $7 million. Cancom bought 10 percent interest in Leosat Corp. of Washington, DC, who are seeking approval to operate a position locator network from low-orbit satellites. Cancom has also become a partner in SovCan Star Satellite Communications Inc., which will build an international satellite system in partnership with Russia. The first satellite in this east-west business network will be placed in a Russian orbital slot over the Atlantic by 1996, and a second satellite will follow for the Pacific region. This annual report of Cancom's activities for 1992 includes financial statements and a six year financial review.

1992-12-01

69

Servicing of geostationary satellites  

NASA Astrophysics Data System (ADS)

Operational features and capabilities of a prospective automated spacecraft servicer for GEO-positioned satellites are described. The servicer spacecraft would have remote manipulation capability and a rendezvous capability, a grappler, a servo-controlled arm, and real-time video cameras. Specific applications for telecommunication satellites are considered, noting that the service module would carry a store of spare component modules for insertion into defective spacecraft. The servicer would be in orbit while a spare parts container, filled with components for satellites with identified defects, is launched into an orbit on an Ariane 4. The container would carry a beacon for the servicer to home in on. The servicer is designed for a 5-7 year autonomous life, would consume 250 W, have a 10 kbit/sec telemetry link and two 6 Mbit/sec video links, a one meter antenna, and 20 W of RF power. Visits to 12 satellites are foreseen for the 1050 kg spacecraft.

Grosjean, O.; Pircher, M.; Prado, J.-Y.; Runavot, J.-J.

1982-09-01

70

Satellite communications for disaster relief operations  

NASA Technical Reports Server (NTRS)

The use of communication satellite systems to provide assistance in disaster relief operations on a global basis is presented. Disaster problem phases such as detection, warning, and relief; requirements for the communication capability including remote data collection, imaging and voice broadcast; and the global disaster network are discussed. Utilization of Intelsat and Marisat systems and the size and type of ground terminals required for satellite access is considered, and estimates of communication requirements for a global system and of costs for satellite services to support relief operations are given. NASA disaster related activities including studies of direct-to-home disaster warning and determination of disaster response times are described, and it is concluded that existing international satellite communication systems offer real potential for the establishment of a reliable and flexible network devoted to disaster related communication services.

Sivo, J. N.

1979-01-01

71

78 FR 14920 - Earth Stations Aboard Aircraft Communicating With Fixed-Satellite Service Geostationary-Orbit...  

Federal Register 2010, 2011, 2012, 2013

...IB Docket No. 12-376; FCC 12-161] Earth Stations Aboard Aircraft Communicating With...establishes technical and licensing rules for Earth Stations Aboard Aircraft (ESAA), i.e., earth stations on aircraft communicating with...

2013-03-08

72

Role of satellite communications in integrated business communications  

NASA Astrophysics Data System (ADS)

The geographic and service integration of business communication networks that include satellite links are explored. Voice, data, bulk data, teleconferencing, and document distribution services are expected to be found at user earth-station sites. Similar capabilities can be expected at regional facilities located off the earth-station site. This geographic and service integration, built on a satellite network backbone, offers a major opportunity to achieve improved business productivity in the 1980's.

Russell, D. C.

73

Personal communications services  

Microsoft Academic Search

The history of the US Federal Communications Commission (FCC) examination of proposals to allocate radio frequency spectrum to a new and innovative range of services it calls personal communications services (PCS) is outlined. Personal communication networks (PCN), which will supply mobile two-way, mass-market communications services, the most advanced offering of the PCS area, and spectrum allocation for PCS are discussed.

G. T. Hardy

1992-01-01

74

AUSSAT mobile satellite services  

NASA Technical Reports Server (NTRS)

An overview of AUSSAT's planned mobile satellite system is given. The development program which is being undertaken to achieve the 1992 service date is described. Both business and technical aspects of the development program are addressed.

Nowland, Wayne L.; Wagg, Michael; Simpson, Daniel

1988-01-01

75

AUSSAT Mobile Satellite Services.  

National Technical Information Service (NTIS)

An overview of AUSSAT's planned mobile satellite system is given. The development program which is being undertaken to achieve the 1992 service date is described. Both business and technical aspects of the development program are addressed.

W. L. Nowland M. Wagg D. Simpson

1988-01-01

76

Japan's CS (Sakura) communications satellite experiments. VI D - Communications Experiments: New applications to satellite communications  

NASA Astrophysics Data System (ADS)

An outline is presented of communications satellite (CS) applied systems experiments and results obtained in areas of public service (the National Police Agency of Japan, and Japan National Railways), computer network services, and advanced teleconference system experiments. Two distinct approaches to computer communications are examined: (1) centralized and distributed controlled computer network experiments, and (2) a high-speed computer communications experiment. The interoffice packet signal transmission experiment is discussed as well as news transmission experiments, an enhanced video-conferencing experiment and a precise time-comparison and dissemination experiment.

Takahashi, H.; Saruwatari, T.; Imae, M.; Suzuki, M.; Nakashima, H.

1986-05-01

77

76 FR 79110 - Service Rules and Policies for the Broadcasting Satellite Service (BSS)  

Federal Register 2010, 2011, 2012, 2013

...Rules and Policies for the Broadcasting Satellite Service (BSS) AGENCY: Federal Communications...Rules and Policies for the Broadcasting Satellite Service (BSS), Report and Order...INFORMATION CONTACT: Lynne Montgomery, Satellite Division, International Bureau,...

2011-12-21

78

75 FR 49871 - Fixed and Mobile Services in the Mobile Satellite Service  

Federal Register 2010, 2011, 2012, 2013

...Fixed and Mobile Services in the Mobile Satellite Service AGENCY: Federal Communications...allocations to the existing Mobile-Satellite allocation. This will lay the groundwork...while also ensuring market-wide mobile satellite capability to serve important needs...

2010-08-16

79

75 FR 13085 - Pan-Pacific Education and Communications Experiments by Satellite (PEACESAT): Closing Date  

Federal Register 2010, 2011, 2012, 2013

...Education and Communications Experiments by Satellite (PEACESAT): Closing Date AGENCY...Education and Communications Experiments by Satellite (PEACESAT) Program. Projects funded...the PEACESAT Program's acquisition of satellite communications to service Pacific...

2010-03-18

80

Advanced satellite communication system  

NASA Technical Reports Server (NTRS)

The objective of this research program was to develop an innovative advanced satellite receiver/demodulator utilizing surface acoustic wave (SAW) chirp transform processor and coherent BPSK demodulation. The algorithm of this SAW chirp Fourier transformer is of the Convolve - Multiply - Convolve (CMC) type, utilizing off-the-shelf reflective array compressor (RAC) chirp filters. This satellite receiver, if fully developed, was intended to be used as an on-board multichannel communications repeater. The Advanced Communications Receiver consists of four units: (1) CMC processor, (2) single sideband modulator, (3) demodulator, and (4) chirp waveform generator and individual channel processors. The input signal is composed of multiple user transmission frequencies operating independently from remotely located ground terminals. This signal is Fourier transformed by the CMC Processor into a unique time slot for each user frequency. The CMC processor is driven by a waveform generator through a single sideband (SSB) modulator. The output of the coherent demodulator is composed of positive and negative pulses, which are the envelopes of the chirp transform processor output. These pulses correspond to the data symbols. Following the demodulator, a logic circuit reconstructs the pulses into data, which are subsequently differentially decoded to form the transmitted data. The coherent demodulation and detection of BPSK signals derived from a CMC chirp transform processor were experimentally demonstrated and bit error rate (BER) testing was performed. To assess the feasibility of such advanced receiver, the results were compared with the theoretical analysis and plotted for an average BER as a function of signal-to-noise ratio. Another goal of this SBIR program was the development of a commercial product. The commercial product developed was an arbitrary waveform generator. The successful sales have begun with the delivery of the first arbitrary waveform generator.

Staples, Edward J.; Lie, Sen

1992-01-01

81

78 FR 14952 - Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit...  

Federal Register 2010, 2011, 2012, 2013

...IB Docket No. 12-376; FCC 12-161] Earth Stations Aboard Aircraft Communicating...proposal to elevate the allocation status of Earth Stations Aboard Aircraft (ESAA) in the...11.7-12.2 GHz band (space-to-Earth), on an unprotected basis in...

2013-03-08

82

Interim Service ISDN Satellite (ISIS) network model for advanced satellite designs and experiments  

NASA Technical Reports Server (NTRS)

The Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) Network Model for Advanced Satellite Designs and Experiments describes a model suitable for discrete event simulations. A top-down model design uses the Advanced Communications Technology Satellite (ACTS) as its basis. The ISDN modeling abstractions are added to permit the determination and performance for the NASA Satellite Communications Research (SCAR) Program.

Pepin, Gerard R.; Hager, E. Paul

1991-01-01

83

Inmarsat second generation satellites for mobile communications  

NASA Astrophysics Data System (ADS)

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

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

84

A design of 30/20 GHz flight communications experiment for NASA. [satellite and earth segments for high data rate commercial service  

NASA Technical Reports Server (NTRS)

The objective of the 30/20 GHz Flight Experiment System is to develop the required technology and to experiment with the communication technique for an operational communication satellite system. The system uses polarization, spatial, and frequency isolations to maximize the spectrum utilization. The key spacecraft technologies required for the concept are the scan beam antenna, the baseband processor, the IF switch matrix, TWTA, SSPA, and LNA. The spacecraft communication payload information will be telemetered and monitored closely so that these technologies and performances can be verified. Two types of services, a trunk service and a customer premise service, are demonstrated in the system. Many experiments associated with these services, such as synchronization, demand assignment, link control, and network control will be performed to provide important information on the operational aspect of the system.

Kawamoto, Y.

1982-01-01

85

Satellite communications - Intelsat and global patterns  

NASA Astrophysics Data System (ADS)

The global pattern of mankind's population growth is examined, taking into account the exponential increase in population which began only in the 17th century. As world population has grown, trade has increased, and transportation and communications have become vitally important. A revolution in global communications was initiated when Intelsat launched the first international communications satellite, 'Early Bird', in April 1965. Since April 1965, a tremendous development in global communications by means of satellites has taken place. The Intelsat VI satellite will have a capacity of 36,000 telephone circuits plus 2 TV channels, while the capacity of Early Bird was only 240 telephone circuits. Today, Intelsat is truly an international organization which includes 108 member countries. Attention is given to the particular importance of the Intelsat services to the developing countries, the exploration of new technologies and system concepts, and the extension of services to those portions of the global village which have remained electronically isolated.

Astrain, S.

1983-10-01

86

Encryption protection for communication satellites  

NASA Astrophysics Data System (ADS)

In connection with the growing importance of the commercial communication satellite systems and the introduction of new technological developments, users and operators of these systems become increasingly concerned with aspects of security. The user community is concerned with maintaining confidentiality and integrity of the information being transmitted over the satellite links, while the satellite operators are concerned about the safety of their assets in space. In response to these concerns, the commercial satellite operators are now taking steps to protect the communication information and the satellites. Thus, communication information is being protected by end-to-end encryption of the customer communication traffic. Attention is given to the selection of the NBS DES algorithm, the command protection systems, and the communication protection systems.

Sood, D. R.; Hoernig, O. W., Jr.

87

Communications and media services  

NASA Technical Reports Server (NTRS)

NASA's internal and external communication methods are reviewed. NASA information services for the media, for the public, and for employees are discussed. Consideration is given to electron information distribution, the NASA TV-audio system, the NASA broadcast news service, astronaut appearances, technology and information exhibits, speaker services, and NASA news reports for internal communications. Also, the NASA worldwide electronic mail network is described and trends for future NASA communications and media services are outlined.

Mcculla, James W.; Kukowski, James F.

1990-01-01

88

Web Services for Service-Oriented Communication  

Microsoft Academic Search

Service-Oriented Communication (SOC) is a new development in the industry to enable communication through web services and SOA. SOC is to make communication as service and provide a service-oriented architecture to integrate communication in business applications. Recent advances of web service and SOA have made it possible for a full web service and SOA based communication paradigm over IP. This

Wu Chou; Feng Liu

2006-01-01

89

Web Services for Service-Oriented Communication  

Microsoft Academic Search

Service-oriented communication (SOC) is a new development in the industry to enable communication through Web services and SOA. SOC is to make communication as service and provide a service-oriented architecture to integrate communication in business applications. Recent advances of Web service and SOA have made it possible for a full Web service and SOA based communication paradigm over IP. This

Wu Chou; Feng Liu

2006-01-01

90

Satellite servicing economic study  

NASA Technical Reports Server (NTRS)

Previous studies have shown that satellite servicing is cost effective; however, all of these studies were of different formats, dollar year, learning rates, availability, etc. Threfore, it was difficult to correlate any useful trends from these studies. The reviewed study was initiated to correlate the economic data into a common data base, using a common set of assumptions. A selected set of existed funded programs was then analyzed to provide an independent analysis of the servicing options and potential economic benefits.

1990-01-01

91

Satellite servicing economic study  

NASA Technical Reports Server (NTRS)

Previous studies have shown that satellite servicing is cost effective; however, all of these studies were of different formats, dollar year, learning rates, availability, etc. Therefore, it was difficult to correlate any useful trends from these studies. The reviewed study was initiated to correlate the economic data into a common data base, using a common set of assumptions. A selected set of existed funded programs was then analyzed to provide an independent analysis of the servicing options and potential economic benefits.

1990-01-01

92

Odyssey, an optimized personal communications satellite system  

NASA Astrophysics Data System (ADS)

Personal communications places severe demands on service providers and transmission facilities. Customers are not satisfied with the current levels of service and want improvements. Among the characteristics that users seek are: lower service rates, hand held convenience, acceptable time delays, ubiquitous service, high availability, reliability, and high quality. The space industry in developing commercial space systems for providing mobile communications to personal telephones. Provision of land mobile satellite service is fundamentally different from the fixed satellite service provided by geostationary satellites. In fixed service, the earth based antennas can depend on a clear path from user to satellite. Mobile users in a terrestrial environment commonly encounter blockage due to vegetation, terrain or buildings. Consequently, high elevation angles are of premium value. TRW studied the issues and concluded that a Medium Earth Orbit constellation is the best solution for Personal Communications Satellite Service. TRW has developed Odyssey, which uses twelve satellites in medium altitude orbit to provide personal communications satellite service. The Odyssey communications system projects a multibeam antenna pattern to the Earth. The attitude control system orients the satellites to ensure constant coverage of land mass and coastal areas. Pointing can be reprogrammed by ground control to ensure optimized coverage of the desired service areas. The payload architecture features non-processing, 'bent pipe' transponders and matrix amplifiers to ensure dynamic power delivery to high demand areas. Circuit capacity is 3000 circuits per satellite. Each satellite weighs 1917 kg (4226 pounds) at launch and the solar arrays provide 3126 watts of power. Satellites are launched in pairs on Ariane, Atlas, or other vehicles. Each satellite is placed in a circular orbit at an altitude of 10,354 km. satellites permits phased introduction of service. After only three launches, in which two satellites are launched into each plane, continuous service can be provided to most of the world. After three more launches for a total of 12 satellites, service can be expanded to all populated regions of the Earth with path diversity to most regions. *The Odyssey system is superior to both geostationary satellites and low earth orbiting satellites. -Odyssey provides many benefits to the end user which are described in the paper. These include: low cost, convenience, high availability, reliability, and acceptable time delay. Odyssey exhibits benefits for telecommunications operators: simple operations, incremental, phased startup, long space segment life-time, high profitability, dynamic flexibility for adjustment and short time to market. %Since submission of an FCC application in 1991, TRW has continued to explore ways to further improve the Odyssey approach by expanding coverage to the entire world and reducing the initial investment while maintaining high quality service.

Rusch, Roger J.

93

Mobile satellite service in the United States  

NASA Technical Reports Server (NTRS)

Mobile satellite service (MSS) has been under development in the United States for more than two decades. The service will soon be provided on a commercial basis by a consortium of eight U.S. companies called the American Mobile Satellite Consortium (AMSC). AMSC will build a three-satellite MSS system that will offer superior performance, reliability and cost effectiveness for organizations requiring mobile communications across the U.S. The development and operation of MSS in North America is being coordinated with Telesat Canada and Mexico. AMSC expects NASA to provide launch services in exchange for capacity on the first AMSC satellite for MSAT-X activities and for government demonstrations.

Agnew, Carson E.; Bhagat, Jai; Hopper, Edwin A.; Kiesling, John D.; Exner, Michael L.; Melillo, Lawrence; Noreen, Gary K.; Parrott, Billy J.

1988-01-01

94

Antennas for mobile satellite communications  

NASA Astrophysics Data System (ADS)

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

Huang, John

1991-12-01

95

Trends in mobile satellite communication  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

96

Coding for reliable satellite communications  

NASA Technical Reports Server (NTRS)

This research project was set up to study various kinds of coding techniques for error control in satellite and space communications for NASA Goddard Space Flight Center. During the project period, researchers investigated the following areas: (1) decoding of Reed-Solomon codes in terms of dual basis; (2) concatenated and cascaded error control coding schemes for satellite and space communications; (3) use of hybrid coding schemes (error correction and detection incorporated with retransmission) to improve system reliability and throughput in satellite communications; (4) good codes for simultaneous error correction and error detection, and (5) error control techniques for ring and star networks.

Gaarder, N. T.; Lin, S.

1986-01-01

97

[Theme Issue: Communications Satellites.  

ERIC Educational Resources Information Center

One section of this journal is devoted to issues involving broadcast satellites. Separate articles discuss the need for international planning of satellite broadcasting, decisions made at the 1971 World Administrative Radio Conference for Space Telecommunications, potential problems in satellite broadcasting, a series of proposals drawn up by the…

Howkins, John, Ed.

1976-01-01

98

Modulation and coding used by a major satellite communications company  

NASA Technical Reports Server (NTRS)

Hughes Communications Inc., is a major satellite communications company providing or planning to provide the full spectrum of services available on satellites. All of the current services use conventional modulation and coding techniques that were well known a decade or longer ago. However, the future mobile satellite service will use significantly more advanced techniques. JPL, under NASA sponsorship, has pioneered many of the techniques that will be used.

Renshaw, K. H.

1992-01-01

99

Operating Frequencies for Educational Satellite Services.  

ERIC Educational Resources Information Center

Part of a continuing study of application of communication satellites for helping to meet educational needs, this memorandum discusses operating frequencies for educational satellite services. Each of the factors affecting choice of transmission frequencies is identified and discussed in a separate section. Included among these factors are…

Singh, Jai P.

100

Satellite Communications Using Commercial Protocols.  

National Technical Information Service (NTIS)

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 ...

W. D. Ivancic J. H. Griner R. Dimond B. D. Frantz B. Kachmar D. Shell

2000-01-01

101

Technology requirements for post-1985 communications satellites  

NASA Technical Reports Server (NTRS)

The technical and functional requirements for commercial communication satellites are discussed. The need for providing quality service at an acceptable cost is emphasized. Specialized services are postulated in a needs model which forecasts future demands. This needs model is based upon 322 separately identified needs for long distance communication. It is shown that the 1985 demand for satellite communication service for a domestic region such as the United States, and surrounding sea and air lanes, may require on the order of 100,000 MHz of bandwith. This level of demand can be met by means of the presently allocated bandwidths and developing some key technologies. Suggested improvements include: (1) improving antennas so that high speed switching will be possible; (2) development of solid state transponders for 12 GHz and possibly higher frequencies; (3) development of switched or steered beam antennas with 10 db or higher gain for aircraft; and (4) continued development of improved video channel compression techniques and hardware.

Burtt, J. E.; Moe, C. R.; Elms, R. V.; Delateur, L. A.; Sedlacek, W. C.; Younger, G. G.

1973-01-01

102

Satellite Applications for Public Service: Project Summaries.  

National Technical Information Service (NTIS)

Summaries of 18 different projects involving the use of satellite communications are presented in this report, including PEACESAT Education and Communication Experiments, USP Network Satellite Communication Project, Project Satellite, Satellite Instructio...

S . Lauffer

1979-01-01

103

Power versus stabilization for laser satellite communication.  

PubMed

To establish optical communication between any two satellites, the lines of sight of their optics must be aligned for the duration of the communication. The satellite pointing and tracking systems perform the alignment. The satellite pointing systems vibrate because of tracking noise and mechanical impacts (such as thruster operation, the antenna pointing mechanism, the solar array driver, navigation noise, tracking noise). These vibrations increase the bit error rate (BER) of the communication system. An expression is derived for adaptive transmitter power that compensates for vibration effects in heterodyne laser satellite links. This compensation makes it possible to keep the link BER performance constant for changes in vibration amplitudes. The motivation for constant BER is derived from the requirement for future satellite communication networks with high quality of service. A practical situation of a two-low-Earth-orbit satellite communication link is given. From the results of the example it is seen that the required power for a given BER increases almost exponentially for linear increase in vibration amplitude. PMID:18319913

Arnon, S

1999-05-20

104

A series on optimizing satellite systems. I - Restoring interruptions of communications sattelite service: Logistical and cost comparisons of mature and newly operational systems  

NASA Astrophysics Data System (ADS)

A mathematical model is presented of costs and operational factors involved in provision for service interruptions of both a mature and typically large incumbent satellite system and of a smaller, more recently operational system. The equation expresses the required launch frequency for the new system as a function of the launch spacing of the mature system; the time disparity between the inauguration of the two systems; and the rate of capacity depreciation. In addition, a technique is presented to compare the relative extent to which the discounted costs of the new system exceed those of the mature system in furnishing the same effective capacity in orbit, and thus the same service liability, at a given point in time. It is determined that a mature incumbent communications satellite system, having more capacity in orbit, will on balance have a lower probability of service interruption than a newer, smaller system.

Snow, Marcellus S.

1989-09-01

105

Widgetizing Communication Services  

Microsoft Academic Search

In this paper we propose a framework of building communication features as web widgets and compose these widgets to better serve users with highly customizable features, friendly user interfaces, and easier integration with other web services. We address several challenges of the widgetizing process, including feature interaction handling, inter-widget communication, integrating phone, desktop and network communication resources. We also present

Xiaotao Wu; Venkatesh Krishnaswamy

2010-01-01

106

Global trade in satellites and launch services  

NASA Astrophysics Data System (ADS)

Hearing before the Subcommittee on Space of the Committee on Science, Space, and Technology of the House of Representatives is presented. Written testimony, submittals for the record, and responses to written questions are included. Topics concerning the global trade in satellites and launch services include foreign competition, the China and Russia trade agreements, Commerce licensing on international sales and export, trade control, technology transfer, satellite communications and the economy, satellites and the global information infrastructure, commercial space revenues, and enforcement of trade policies.

107

Satellite-based quantum communications  

NASA Astrophysics Data System (ADS)

Single-photon quantum communications offers the attractive feature of ``future proof'' security rooted in the laws of quantum physics for the transfer of cryptographic keys. Secure distribution of keys is necessary for the encryption and authentication of conventional communications. Ground-based quantum communications experiments in optical fiber have attained transmission ranges in excess of 200km, but for larger distances to become feasible we proposed a methodology that would make satellite-to-ground quantum communications possible. Satellite feasibility studies have been published by research groups in the US, Europe, Japan and China, and collaborations in several countries have published conceptual experimental plans. In this talk we will review the main features required for low-earth orbit satellite-toground quantum communications, and describe the results of ground-based quantum communications experiments across atmospheric paths conducted by our team over the past decade. Using these results as an anchor, we will describe a link model, incorporating photon transmission, loss and background physical processes, for estimating satellite-to-ground quantum communications performance. We will show results from this model for the projected performance of a hypothetical quantum communications terminal on the International Space Station, with a hypothetical ground terminal in Los Alamos, NM.

Hughes, Richard

2011-06-01

108

Potential markets for advanced satellite communications  

NASA Technical Reports Server (NTRS)

This report identifies trends in the volume and type of traffic offered to the U.S. domestic communications infrastructure and extrapolates these trends through the year 2011. To describe how telecommunications service providers are adapting to the identified trends, this report assesses the status, plans, and capacity of the domestic communications infrastructure. Cable, satellite, and radio components of the infrastructure are examined separately. The report also assesses the following major applications making use of the infrastructure: (1) Broadband services, including Broadband Integrated Services Digital Network (BISDN), Switched Multimegabit Data Service (SMDS), and frame relay; (2) mobile services, including voice, location, and paging; (3) Very Small Aperture Terminals (VSAT), including mesh VSAT; and (4) Direct Broadcast Satellite (DBS) for audio and video. The report associates satellite implementation of specific applications with market segments appropriate to their features and capabilities. The volume and dollar value of these market segments are estimated. For the satellite applications able to address the needs of significant market segments, the report also examines the potential of each satellite-based application to capture business from alternative technologies.

Adamson, Steven; Roberts, David; Schubert, Leroy; Smith, Brian; Sogegian, Robert; Walters, Daniel

1993-01-01

109

Integrating communication services  

Microsoft Academic Search

The need for communication services which span multiple communication technologies is growing. Communication services are being developed in three areas: in the public switched telephony networks, on the Internet in the form of integrated multimedia including voice-over-Internet, and in private switched telephony networks in the form of enterprise computer-telephony integration applications. This article shows it is plausible to create unified

C. Low

1997-01-01

110

Evaluating the Peruvian Rural Communication Services Project.  

ERIC Educational Resources Information Center

Reviews the Peruvian Rural Communication Services (PRCS) Project and outlines selected findings. Topics discussed include a brief description of Peru's economic and social conditions; satellite communication systems; audio teleconferencing; telephone service; planning and administration; research design features; data collection; and project…

Mayo, John

1988-01-01

111

47 CFR 25.211 - Analog video transmissions in the Fixed-Satellite Services.  

Code of Federal Regulations, 2013 CFR

...Analog video transmissions in the Fixed-Satellite Services. 25.211 Section 25...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards...Analog video transmissions in the Fixed-Satellite Services. (a) Downlink...

2013-10-01

112

47 CFR 25.215 - Technical requirements for space stations in the Direct Broadcast Satellite Service.  

Code of Federal Regulations, 2013 CFR

...space stations in the Direct Broadcast Satellite Service. 25.215 Section 25.215...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical Standards...space stations in the Direct Broadcast Satellite Service. In addition to §...

2013-10-01

113

47 CFR 25.148 - Licensing provisions for the Direct Broadcast Satellite Service.  

Code of Federal Regulations, 2013 CFR

...Licensing provisions for the Direct Broadcast Satellite Service. 25.148 Section 25.148...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses...Licensing provisions for the Direct Broadcast Satellite Service. (a) License terms....

2013-10-01

114

New TDRSS communications options for small satellites  

NASA Technical Reports Server (NTRS)

The NASA uses a space network which includes the tracking and data relay satellite system (TDRSS) for the provision of reliable low data rate and high data rate relay services between user spacecraft in earth orbit and the ground. In relation to future small satellite designs, new communication options for the TDRSS support of small spacecraft missions are reported on. The technologies considered include new transponder technologies, evolution to Ka band frequencies and a TDRSS demand access service capability. Multiple access aspects are considered.

Zillig, David J.; Perko, Kenneth L.; Nelson, Kathryn G.

1996-01-01

115

Personal Mobile Communications by Satellite.  

National Technical Information Service (NTIS)

The engineering feasibility of satellite systems for paging and message services to mobile users with small terminals is demonstrated. The satellite itself would provide cover mainly in rural and semi-urban areas, but the coverage could be extended into u...

R. J. Cocks P. S. Hansell R. Krawec D. Lewin

1984-01-01

116

NASA compendium of satellite communications programs  

NASA Technical Reports Server (NTRS)

A comprehensive review of worldwide satellite communication programs is reported that ranges in time from the inception of satellite communications to mid-1971. Particular emphasis is placed on program results, including experiments conducted, communications system operational performance, and technology employed.

1971-01-01

117

Military Satellite Communications Systems.  

National Technical Information Service (NTIS)

MILSATCOM systems consist of three primary segments: earth terminal (airborne, ground, sea) segment, sp segment, and control segment. MILSATCOM systems are vital to Department of Defense as they satisfy certain essential communications connectivity needs ...

1992-01-01

118

Mobile Communication Via Satellite  

NASA Technical Reports Server (NTRS)

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

Yan, Tsun-Yee; Naderi, Firouz M.

1988-01-01

119

Spacecraft in switch matrix for wide band service applicatons in 30/20 GHz communications satellite systems  

NASA Technical Reports Server (NTRS)

Bandwidth, switching speed, off-state isolation, and reliability over a ten-year mission were factors in determining the optimum available technology for satellite communications switching in 1982. A proof of concept model for a 20 x 20 coupled crossbar switch matrix designed with FET devices for microwave switching and with high speed CMOS LIS for switch crosspoint addressing was fabricated and tested. Results show the design is feasible for application in a multichannel SS-TDMA communications system. Expandibility can readily be achieved with this design. A conceptual design study for a 100 x 100 switch matrix utilizing a coupled crossbar architecture implemented with a monolithic microwave integrated circuits revealed technology needs for high capacity switch matrices.

Cory, B. J.

1982-01-01

120

Interim Service ISDN Satellite (ISIS) simulator development for advanced satellite designs and experiments  

NASA Technical Reports Server (NTRS)

The simulation development associated with the network models of both the Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) and the Full Service ISDN Satellite (FSIS) architectures is documented. The ISIS Network Model design represents satellite systems like the Advanced Communications Technology Satellite (ACTS) orbiting switch. The FSIS architecture, the ultimate aim of this element of the Satellite Communications Applications Research (SCAR) Program, moves all control and switching functions on-board the next generation ISDN communications satellite. The technical and operational parameters for the advanced ISDN communications satellite design will be obtained from the simulation of ISIS and FSIS engineering software models for their major subsystems. Discrete event simulation experiments will be performed with these models using various traffic scenarios, design parameters, and operational procedures. The data from these simulations will be used to determine the engineering parameters for the advanced ISDN communications satellite.

Pepin, Gerard R.

1992-01-01

121

Worldwide Seamless Cellular Satellite Communications: The Global Mobile Communication by Globalstar System.  

National Technical Information Service (NTIS)

Presentation viewgraphs are presented that describe the need and technology requirements for a worldwide cellular satellite communication system. Specific services provided by such a system are outlined and the role of the service provider is described.

A. J. Navarra

1992-01-01

122

Free-space optical communication satellite networks-vibration effects and possible solutions  

Microsoft Academic Search

A number of serious consortiums develop satellite communication networks. The objective of these communication projects is to service personal communication users almost everywhere on earth. The inter satellite links in those project use microwave radiation as the carrier. Free space optical communication between satellites networked together can make possible high speed communications between different places on earth. The advantages of

Shlomi Arnon; Norman S. Kopeika

1997-01-01

123

Gigabit Satellite Network for NASA's Advanced Communication Technology Satellite (ACTS)  

NASA Technical Reports Server (NTRS)

The advanced communication technology satellite (ACTS) gigabit satellite network provides long-haul point-to-point and point-to-multipoint full-duplex SONET services over NASA's ACTS. at rates up to 622 Mbit/s (SONET OC-12), with signal quality comparable to that obtained with terrestrial fiber networks. Data multiplexing over the satellite is accomplished using time-division multiple access (TDMA) techniques coordinated with the switching and beam hopping facilities provided by ACTS. Transmissions through the satellite are protected with Reed-Solomon encoding. providing virtually error-free transmission under most weather conditions. Unique to the system are a TDMA frame structure and satellite synchronization mechanism that allow: (a) very efficient utilization of the satellite capacity: (b) over-the-satellite dosed-loop synchronization of the network in configurations with up to 64 ground stations: and (c) ground station initial acquisition without collisions with existing signalling or data traffic. The user interfaces are compatible with SONET standards, performing the function of conventional SONET multiplexers and. as such. can be: readily integrated with standard SONET fiber-based terrestrial networks. Management of the network is based upon the simple network management protocol (SNMP). and includes an over-the-satellite signalling network and backup terrestrial internet (IP-based) connectivity. A description of the ground stations is also included.

Hoder, Douglas; Bergamo, Marcos

1996-01-01

124

Communications satellite systems operations with the space station, volume 2  

NASA Technical Reports Server (NTRS)

A financial model was developed which described quantitatively the economics of the space segment of communication satellite systems. The model describes the economics of the space system throughout the lifetime of the satellite. The expected state-of-the-art status of communications satellite systems and operations beginning service in 1995 were assessed and described. New or enhanced space-based activities and associated satellite system designs that have the potential to achieve future communications satellite operations in geostationary orbit with improved economic performance were postulated and defined. Three scenarios using combinations of space-based activities were analyzed: a spin stabilized satellite, a three axis satellite, and assembly at the Space Station and GEO servicing. Functional and technical requirements placed on the Space Station by the scenarios were detailed. Requirements on the satellite were also listed.

Price, K.; Dixon, J.; Weyandt, C.

1987-01-01

125

Coding for reliable satellite communications  

NASA Technical Reports Server (NTRS)

Several error control coding techniques for reliable satellite communications were investigated to find algorithms for fast decoding of Reed-Solomon codes in terms of dual basis. The decoding of the (255,223) Reed-Solomon code, which is used as the outer code in the concatenated TDRSS decoder, was of particular concern.

Lin, S.

1984-01-01

126

Progressive Communication Satellite Systems Design  

Microsoft Academic Search

This paper describes the progressive design, on a phased basis, of a typical communication satellite system capable of meeting a variety of military and civilian applications, The system philosophy stresses reliability and flexibility of operation, with provision for both point-to-point and area coverage, to serve both fixed and mobile ground terminals, and to operate in either a military or nonmilitary

J. E. Bartow; D. L. Jacoby; G. N. Krassner

1960-01-01

127

Satellite Communications: Hopes and Fears  

ERIC Educational Resources Information Center

The potentials of space communication, including the prospects and problems of direct broadcast TV satellites, are examined. Considered are future visions, internal and international goals, economic factors, political constraints, prior consent, U.S. and U.N. positions, and free flow of information. (LBH)

Sirkin, Abraham M.

1978-01-01

128

Federal research and development for satellite communications  

NASA Technical Reports Server (NTRS)

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

1977-01-01

129

Lens Antenna For Mobile/Satellite Communication  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

130

NOAA Satellite and Information Service  

NSDL National Science Digital Library

"The Satellite Services Division of the National Environmental Satellite, Data, and Information Service (NESDIS) provides real time access to satellite data and products for the public and government." Users can locate Hazard Mapping System (HMS) Fire Analysis, real-time satellite fire monitoring, Web-based GIS fire analysis, and additional fire products. The OSEI (Operational Significant Event Imagery) link supplies archived and current images of flood events, severe weather, tropical cyclones, and other significant environmental events. Researchers can find technical information on the satellites. Individuals can also find bulletins, advisories, text data, and images of precipitation, snow and ice, volcanic activity, winds, and tropical weather.

131

47 CFR 25.225 - Geographic Service Requirements for 17/24 GHz Broadcasting Satellite Service.  

Code of Federal Regulations, 2010 CFR

... COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical...for 17/24 GHz Broadcasting Satellite Service. (a) Each...a) of this section must design and configure its space station...comparable to the service that such satellites will provide to CONUS...

2009-10-01

132

47 CFR 25.225 - Geographic Service Requirements for 17/24 GHz Broadcasting Satellite Service.  

Code of Federal Regulations, 2010 CFR

... COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Technical...for 17/24 GHz Broadcasting Satellite Service. (a) Each...a) of this section must design and configure its space station...comparable to the service that such satellites will provide to CONUS...

2010-10-01

133

Survey of Satellite Communications System Vulnerabilities.  

National Technical Information Service (NTIS)

The U.S. military's increasing reliance on commercial and military communications satellites to enable widely-dispersed, mobile forces to communicate makes these space assets increasingly vulnerable to attack by adversaries. Attacks on these satellites co...

J. A. Steinberger

2008-01-01

134

Research Supporting Satellite Communications Technology  

NASA Technical Reports Server (NTRS)

This report describes the second year of research effort under the grant Research Supporting Satellite Communications Technology. The research program consists of two major projects: Fault Tolerant Link Establishment and the design of an Auto-Configurable Receiver. The Fault Tolerant Link Establishment protocol is being developed to assist the designers of satellite clusters to manage the inter-satellite communications. During this second year, the basic protocol design was validated with an extensive testing program. After this testing was completed, a channel error model was added to the protocol to permit the effects of channel errors to be measured. This error generation was used to test the effects of channel errors on Heartbeat and Token message passing. The C-language source code for the protocol modules was delivered to Goddard Space Flight Center for integration with the GSFC testbed. The need for a receiver autoconfiguration capability arises when a satellite-to-ground transmission is interrupted due to an unexpected event, the satellite transponder may reset to an unknown state and begin transmitting in a new mode. During Year 2, we completed testing of these algorithms when noise-induced bit errors were introduced. We also developed and tested an algorithm for estimating the data rate, assuming an NRZ-formatted signal corrupted with additive white Gaussian noise, and we took initial steps in integrating both algorithms into the SDR test bed at GSFC.

Horan Stephen; Lyman, Raphael

2005-01-01

135

Rural Communications Planning Methodology for Integrating Satellite and Terrestrial Facilities.  

National Technical Information Service (NTIS)

A computer program is described which optimizes the design of rural telephone networks by choosing the best combination of cable, open wire, VHF radio, communications satellite stations, and placement of local exchanges. Each service area is described for...

R. G. Sharma

1976-01-01

136

47 CFR 25.143 - Licensing provisions for the 1.6/2.4 GHz mobile-satellite service and 2 GHz mobile-satellite...  

Code of Federal Regulations, 2010 CFR

...provisions for the 1.6/2.4 GHz mobile-satellite service and 2 GHz mobile-satellite service. 25.143 Section 25.143 Telecommunication...COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and...

2009-10-01

137

47 CFR 25.143 - Licensing provisions for the 1.6/2.4 GHz Mobile-Satellite Service and 2 GHz Mobile-Satellite...  

Code of Federal Regulations, 2013 CFR

...provisions for the 1.6/2.4 GHz Mobile-Satellite Service and 2 GHz Mobile-Satellite Service. 25.143 Section 25.143 Telecommunication...COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and...

2013-10-01

138

47 CFR 25.143 - Licensing provisions for the 1.6/2.4 GHz mobile-satellite service and 2 GHz mobile-satellite...  

Code of Federal Regulations, 2010 CFR

...provisions for the 1.6/2.4 GHz mobile-satellite service and 2 GHz mobile-satellite service. 25.143 Section 25.143 Telecommunication...COMMISSION (CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and...

2010-10-01

139

Satellite communications for the Pacific islands. Second year report  

NASA Technical Reports Server (NTRS)

Requirements, options and costs for use of communications satellites in underserved areas of the Pacific Basin are described with emphasis on extended utilization of INTELSAT. The economic structures within and among Pacific Basin entities are examined, particularly the relationship between the growth of regional trade and telecommunications potential for the region. Suitable satellite services are recommended and the financial implications for extended utilization of communications satellites in the Pacific Basin are considered.

Young, E.; Hurd, J. N.

1982-01-01

140

Trends in NASA communication satellites  

NASA Technical Reports Server (NTRS)

Satellite telecommunications can help to satisfy several national needs such as education, health care, cultural opportunities, and data transfer. There are current experiments being conducted with NASA spacecraft ATS 1, 3, and 5 in an attempt to satisfy these national needs. Future experiments are planned for the ATS F/G and CTS spacecrafts. The next generation of communications satellites must provide multiple region coverage, multichannel capability, high quality TV pictures, and must allow low cost ground receivers to be used. The proposed NASA spacecrafts, ATS H/I, will satisfy these requirements. Other countries of the world can benefit from ATS H/I technology.

Sivo, J. N.; Robbins, W. H.; Stretchberry, D. M.

1972-01-01

141

Launch vehicles for communications satellites  

NASA Technical Reports Server (NTRS)

After giving brief development histories of the Delta and the Atlas Centaur launch vehicles, attention is given to the operational characteristics of the ascent, parking orbit, transfer orbit, and orbital insertion phases of the delivery of a communications satellite to a geostationary orbit by means of a Delta launch vehicle. NASA plans to employ Delta vehicles for as long as they are needed during the transition period to the Space Shuttle. NASA planning for Atlas Centaur includes launches through 1985 for INTELSAT-VA, and through 1986 for FLTSATCOM satellites.

Mahon, J. B.

1982-01-01

142

Satellite communications systems and technology. Executive Summary  

NASA Technical Reports Server (NTRS)

NASA and the National Science Foundation (NSF) commissioned a panel of US experts to study the international status of satellite communications systems and technology. The study covers emerging systems concepts, applications, services, and the attendant technologies. The panel members travelled to Europe, Japan, and Russia to gather information first-hand. They visited 17 sites in Europe, 20 sites in Japan, and four in Russia. These included major manufacturers, government organizations, service providers, and associated R&D facilities. The panel's report was reviewed by the sites visited, by the panel, and by representatives of US industry. The report details the information collected and compares it to US activities.

Edelson, Burton I.; Pelton, Joseph N.; Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert; Mahle, Christoph E.

1993-01-01

143

Healthy satellites provide quality service  

NASA Astrophysics Data System (ADS)

The procedures used by Telesat Canada to ensure the performance of Anik satellites is described. At the Satellite Telemetry, Tracking and Command station, each Anik satellite has its own dedicated antenna. Telemetered information from the satellites is received, processed and forwarded to the Satellite Control Center. There the satellite controllers issue all commands to the satellites, and continually monitor the telemetered data. These data, describing the state of health of the satellites, are then analyzed by engineering specialists. The satellites are held in their precise orbital positions by means of specially developed software. The Anik C and D satellites employ travelling wave tube amplifiers (TWTAs) in the transpounder channels. The TWTA saturated flux density (SFD) and equivalent isotropic radiated power (EIRP) are regularly measured and their trends scrutinized. This ensures that customers receive the radio frequency power needed for high-quality service. The satellite electrical power is supplied by the solar cell array and batteries. Power system performance is evaluated regularly to ensure that power is available to operate the required number of TWTAs. In addition to rain-fades, short service interruptions can be caused by high voltage trip-offs of TWTAs, and by electrostatic discharge related anomalies. To minimize these interruptions, Telesat ensures that the satellite controllers are fully trained and prepared for any eventuality, and the relevant operational procedures are continually refined. A fully trained staff of satellite controllers keep interruptions caused by high voltage trip-offs of TWTAs and by electrostatic discharge to a minimum.

Margittai, Paul

144

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

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

145

Satellite communications systems and technology. Volume 1: Analytical chapters  

NASA Technical Reports Server (NTRS)

This is Volume 1 (Analytical Chapters) of the final report of the NASA/NSF Panel Satellite Communications Systems and Technology. The panel surveyed advanced technology being developed for commercial use in the satellite communications field in Europe, Japan, and Russia. All aspects of satellite communications were considered, including fixed, broadcast, mobile, personal communications, navigation, low earth orbit, and small satellites. The focus was on experimental and advanced technology being developed in R&D and demonstration programs rather than on today's production capabilities. Focus was on commercial satellite technology, and does not review defense-related or other confidential satellite communications capabilities. The NASA/NSF panel concluded that the United States has lost its leading position in many critical satellite communications technologies. Although U.S. industry retains a leading position in today's marketplace for satellite communications systems and services, this position is largely founded on technologies and capabilities developed in the 1960's and 1970's. Because the United States is losing ground with respect to a wide range of technologies and systems that will be key to future communications markets, the market share of the U.S. satellite communications industry is at risk.

Edelson, Burton I. (editor); Pelton, Joseph N. (editor); Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.

1993-01-01

146

Satellite communications systems and technology. Volume 1; Analytic Chapters  

NASA Technical Reports Server (NTRS)

Volume 1 (Analytical Chapters) of the final report of the NASA/NSF Panel Satellite Communications Systems and Technology is presented. The panel surveyed advanced technology being developed for commercial use in the satellite communications field in Europe, Japan, and Russia. All aspects of satellite communications were considered, including fixed, broadcast, mobile, personal communications, navigation, low earth orbit, and small satellites. The focus of the study was on experimental and advanced technology being developed in R&D and demonstration programs rather than on today's production capabilities. The report focuses on commercial satellite technology, and does not review defense-related or other confidential satellite communications capabilities. The NASA/NSF panel concluded that the United States has lost its leading position in many critical satellite communications technologies. Although U.S. industry retains a leading position in today's marketplace for satellite communications systems and services, this position is largely founded on technologies and capabilities developed in the 1960s and 1970s. Because the United States is losing ground with respect to a wide range of technologies and systems that will be key to future communications markets, the market share of the U.S. satellite communications industry is at risk.

Jennings, Raymond D.; Mahle, Christoph E.; Miller, Edward F.; Riley, Lance; Pelton, Joseph N.; Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Edelson, Burton I.; Kwan, Robert K.; Helm, Neil R.

1993-01-01

147

Satellite communications systems and technology. Volume 1: Analytical chapters  

NASA Astrophysics Data System (ADS)

This is Volume 1 (Analytical Chapters) of the final report of the NASA/NSF Panel Satellite Communications Systems and Technology. The panel surveyed advanced technology being developed for commercial use in the satellite communications field in Europe, Japan, and Russia. All aspects of satellite communications were considered, including fixed, broadcast, mobile, personal communications, navigation, low earth orbit, and small satellites. The focus was on experimental and advanced technology being developed in R&D and demonstration programs rather than on today's production capabilities. Focus was on commercial satellite technology, and does not review defense-related or other confidential satellite communications capabilities. The NASA/NSF panel concluded that the United States has lost its leading position in many critical satellite communications technologies. Although U.S. industry retains a leading position in today's marketplace for satellite communications systems and services, this position is largely founded on technologies and capabilities developed in the 1960's and 1970's. Because the United States is losing ground with respect to a wide range of technologies and systems that will be key to future communications markets, the market share of the U.S. satellite communications industry is at risk.

Edelson, Burton I.; Pelton, Joseph N.; Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.

1993-07-01

148

Application of the Iridium Satellite System to Aeronautical Communications  

NASA Technical Reports Server (NTRS)

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.

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

2008-01-01

149

Satellite-Based Quantum Communications  

SciTech Connect

Single-photon quantum communications (QC) offers the attractive feature of 'future proof', forward security rooted in the laws of quantum physics. Ground based quantum key distribution (QKD) experiments in optical fiber have attained transmission ranges in excess of 200km, but for larger distances we proposed a methodology for satellite-based QC. Over the past decade we have devised solutions to the technical challenges to satellite-to-ground QC, and we now have a clear concept for how space-based QC could be performed and potentially utilized within a trusted QKD network architecture. Functioning as a trusted QKD node, a QC satellite ('QC-sat') could deliver secret keys to the key stores of ground-based trusted QKD network nodes, to each of which multiple users are connected by optical fiber or free-space QC. A QC-sat could thereby extend quantum-secured connectivity to geographically disjoint domains, separated by continental or inter-continental distances. In this paper we describe our system concept that makes QC feasible with low-earth orbit (LEO) QC-sats (200-km-2,000-km altitude orbits), and the results of link modeling of expected performance. Using the architecture that we have developed, LEO satellite-to-ground QKD will be feasible with secret bit yields of several hundred 256-bit AES keys per contact. With multiple ground sites separated by {approx} 100km, mitigation of cloudiness over any single ground site would be possible, potentially allowing multiple contact opportunities each day. The essential next step is an experimental QC-sat. A number of LEO-platforms would be suitable, ranging from a dedicated, three-axis stabilized small satellite, to a secondary experiment on an imaging satellite. to the ISS. With one or more QC-sats, low-latency quantum-secured communications could then be provided to ground-based users on a global scale. Air-to-ground QC would also be possible.

Hughes, Richard J [Los Alamos National Laboratory; Nordholt, Jane E [Los Alamos National Laboratory; Mc Cabe, Kevin P [Los Alamos National Laboratory; Newell, Raymond T [Los Alamos National Laboratory; Pterson, Charles G [Los Alamos National Laboratory

2010-09-20

150

Defense satellite communications system - Past, present, and future  

NASA Astrophysics Data System (ADS)

This is a critical point in the long history of the Defense Satellite Communications System. This workhorse communications system has developed from the humble beginnings in the 1960s into today's highly capable backbone of U.S. Government Communications. After a long delay these satellites are being launched again and plan to quickly rebuild this critical national asset which has been held together by determination and sweat following the Challenger disaster. The critical issue is what services shall DSCS provide in the future. The process of defining the SHF communications capability of the next generation of these satellites to support the military needs of the next century is under way.

Cook, Robert G.

1992-03-01

151

An advanced domestic satellite communications system  

NASA Technical Reports Server (NTRS)

An updated traffic projection for U.S. domestic satellite communications service covering a period of 15 years; mid-1980 to mid-1995 was prepared. This model takes into account expected technology advances and reductions in transmission costs, legislative and regulatory changes permitting increased competition, and rising energy costs which will encourage more extensive substitution of telecommunications for travel. The historical development and current status of satellite systems are discussed as well as the characteristics of follow-on systems. Orbital arc utilization, spacecraft configuration for single shuttle launch, Earth station configuration, and system costs are examined. Areas which require technology development include multiple beam frequency reuse antennas, on-board switching, intersatellite links, and ka-band operation. Packing and deployment schemes for enclosing the satellite within the shuttle orbiter bay must also be devised.

1980-01-01

152

Estimation of the Demand for Public Services Communications.  

National Technical Information Service (NTIS)

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

1976-01-01

153

47 CFR 25.145 - Licensing provisions for the Fixed-Satellite Service in the 20/30 GHz bands.  

Code of Federal Regulations, 2013 CFR

... Licensing provisions for the Fixed-Satellite Service in the 20/30 GHz bands. ...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses... Licensing provisions for the Fixed-Satellite Service in the 20/30 GHz...

2013-10-01

154

47 CFR 25.144 - Licensing provisions for the 2.3 GHz satellite digital audio radio service.  

Code of Federal Regulations, 2013 CFR

...Licensing provisions for the 2.3 GHz satellite digital audio radio service. 25...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses...Licensing provisions for the 2.3 GHz satellite digital audio radio service....

2013-10-01

155

47 CFR 25.144 - Licensing provisions for the 2.3 GHz satellite digital audio radio service.  

Code of Federal Regulations, 2010 CFR

...Licensing provisions for the 2.3 GHz satellite digital audio radio service. 25...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses...Licensing provisions for the 2.3 GHz satellite digital audio radio service....

2009-10-01

156

47 CFR 25.142 - Licensing provisions for the non-voice, non-geostationary mobile-satellite service.  

Code of Federal Regulations, 2010 CFR

...non-voice, non-geostationary mobile-satellite service. 25.142 Section 25.142...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses...non-voice, non-geostationary mobile-satellite service. (a) Space station...

2009-10-01

157

47 CFR 25.142 - Licensing provisions for the non-voice, non-geostationary mobile-satellite service.  

Code of Federal Regulations, 2010 CFR

...non-voice, non-geostationary mobile-satellite service. 25.142 Section 25.142...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and Licenses...non-voice, non-geostationary mobile-satellite service. (a) Space station...

2010-10-01

158

Olympus: The communications satellite and its uses. An introduction  

NASA Astrophysics Data System (ADS)

Olympus is the largest civil communications satellite ever launched. It is owned and operated by the European Space Agency (ESA) and is in a geostationary orbit at longitude 19 degrees W. Olympus was specifically designed to test the technologies needed for future satellite applications and services. However, capacity is also available to demonstrate new services via satellite such as tele-education and business communications. All the payloads are powerful enough to be used with very small earth stations. Olympus carries four quite distinct payloads, each with its own steerable antennas. The payloads are the (Direct) Broadcast Payload, the Specialized Services Payload, the 30/20 GHz Communications Payload, and the Propagation Payload. Various aspects of the services Olympus provides, how to use these services, and details on the payloads are presented.

Longdon, Norman

1991-01-01

159

Satellite communications and broadcasting; Proceedings of the International Conference, London, England, Dec. 2-4, 1986  

NASA Astrophysics Data System (ADS)

Papers are presented on private satellite networks in the U.S.; the competitive market for international satellite services; private satellite networks in Europe; and various applications for satellites, in particular data broadcasting and business communications. Topics discussed include the worldwide regulation of satellite broadcasting and communications; the capabilities of Eutelsat II; trends in satellite technology; and the role of insurance in space industries. Consideration is given to the use of the ASTRA satellite for TV broadcasting; the services provided by Intelsat; the evolution of American television due to satellites; consumer satellite Television Receive Only marketing in Europe; and satellite programming.

160

Internetworking satellite and local exchange networks for personal communications applications  

NASA Technical Reports Server (NTRS)

The demand for personal communications services has shown unprecedented growth, and the next decade and beyond promise an era in which the needs for ubiquitous, transparent and personalized access to information will continue to expand in both scale and scope. The exchange of personalized information is growing from two-way voice to include data communications, electronic messaging and information services, image transfer, video, and interactive multimedia. The emergence of new land-based and satellite-based wireless networks illustrates the expanding scale and trend toward globalization and the need to establish new local exchange and exchange access services to meet the communications needs of people on the move. An important issue is to identify the roles that satellite networking can play in meeting these new communications needs. The unique capabilities of satellites, in providing coverage to large geographic areas, reaching widely dispersed users, for position location determination, and in offering broadcast and multicast services, can complement and extend the capabilities of terrestrial networks. As an initial step in exploring the opportunities afforded by the merger of satellite-based and land-based networks, several experiments utilizing the NASA ACTS satellite and the public switched local exchange network were undertaken to demonstrate the use of satellites in the delivery of personal communications services.

Wolff, Richard S.; Pinck, Deborah

1993-01-01

161

MEASURING LATENCY IN IRIDIUM SATELLITE CONSTELLATION DATA SERVICES  

Microsoft Academic Search

Abstract The use of Satellite Communications (SATCOM) has become,essential to operations in both Afghanistan and Iraq. In particular, the Iridium satellite constellation has demonstrated its usefulness and flexibility. It has had significant impact on how operations are conducted. ,Iridium provides users both voice and data services. There are two approaches to sending data over the Iridium network: a circuit-switcheddata service

Margaret M. McMahon; Robert Rathburn

162

A new antenna concept for satellite communications  

NASA Technical Reports Server (NTRS)

A novel antenna configuration of two reflecting surfaces and a phased array is examined for application to satellite communications and shown to be superior in every respect to earlier designs for service to the continental United States from synchronous orbit. The vignetting that afflicts other two reflector optical systems is eliminated by use of a reflecting field element. The remaining aberrations, predominantly coma, are isolated in the time delay distribution at the surface of the array and can be compensated by ordinary array techniques. The optics exhibits infinite bandwidth and the frequency range is limited only by the design of the array.

Skahill, G.; Ciccolella, D.

1982-01-01

163

Technology requirements for communication satellites in the 1980's  

NASA Technical Reports Server (NTRS)

The key technology requirements are defined for meeting the forecasted demands for communication satellite services in the 1985 to 1995 time frame. Evaluation is made of needs for services and technical and functional requirements for providing services. The future growth capabilities of the terrestrial telephone network, cable television, and satellite networks are forecasted. The impact of spacecraft technology and booster performance and costs upon communication satellite costs are analyzed. Systems analysis techniques are used to determine functional requirements and the sensitivities of technology improvements for reducing the costs of meeting requirements. Recommended development plans and funding levels are presented, as well as the possible cost saving for communications satellites in the post 1985 era.

Burtt, J. E.; Moe, C. R.; Elms, R. V.; Delateur, L. A.; Sedlacek, W. C.; Younger, G. G.

1973-01-01

164

High Altitude Satellite Communications, with Crosslinks.  

National Technical Information Service (NTIS)

Analysis and FORTRAN programs that quantitatively describe the uplink, crosslinks, and downlinks for a 10 satellite, two ground-station satellite communications system are described. The existence of each link (accounting for earth obstruction for crossli...

P. F. Christopher E. R. Edelman S. M. Maciorowski

1977-01-01

165

Satellite communications systems and technology. Volume 2: Site reports  

NASA Technical Reports Server (NTRS)

This is volume 2 of the final report of the NASA/NSF Panel on Satellite Communications Systems and Technology. It consists of the site reports from the panel's visits to satellite communications facilities and laboratories in Europe, Japan, and Russia. The Executive Summary of the panel's final report is published separately. Volume 1, also published separately, consists of the panel's analytical chapters. Information on ordering the Executive Summary and Volume 1 from the National Technical Information Service is included.

Edelson, Burton I. (editor); Pelton, Joseph N. (editor); Bostian, Charles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.

1993-01-01

166

India's domestic satellite communication system - INSAT  

NASA Astrophysics Data System (ADS)

The Indian National Satellite System (INSAT-I) possesses two multipurpose satellites in geostationary orbit, each of which has twelve 36 MHz-wide C-band channels, two 36 MHz-wide S-band channels, a Very High Resolution Radiometer for earth observation in the visible and IR bands, and a 200 kHz-wide Data Relay Transponder. The ground segment of INSAT-I consists of five large earth stations, 13 medium earth stations, 10 remote area terminals, and one mobile emergency communications terminal. C-band channels are to be used for thick and thin route telephony, while S-band channels are devoted to TV broadcasts to community receivers, radio networking, and Disaster Warning System services, using low level injected carriers. Data Collection Platforms relay meteorological and hydrological data via the Data Relay Transponder to a central station.

Kibe, S. V.; Thomas, G.

167

A practical system for regional mobile satellite services  

NASA Technical Reports Server (NTRS)

The Regional Mobile Satellite (MSAT) concept proposes a worldwide, interconnected mobile satellite service (MSS) network in which MSAT-type satellites provide the space segment services to separate regions (i.e., one or a few countries). Using this concept, mobile communications users across entire continents can now be served by a handful of regionally controlled satellites in geostationary earth orbit (GEO). All requirements, including hand-held telephone capabilities, can be cost-effectively provided using proven technologies. While other concepts of regional or global mobile communications continue to be explored, the Hughes Regional MSAT system demonstrates the near-term viability of the GEO approach.

Glein, Randall; Leverson, Denis; Olmstead, Dean

1993-01-01

168

Communications satellite system for Africa  

NASA Astrophysics Data System (ADS)

Earlier established requirement estimations were improved upon by contacting African administrations and organizations. An enormous demand is shown to exist for telephony and teletype services in rural areas. It is shown that educational television broadcasting should be realized in the current African transport and communications decade (1978-1987). Radio broadcasting is proposed in order to overcome illiteracy and to improve educational levels. The technical and commercial feasibility of the system is provided by computer simulations which demonstrate how the required objectives can be fulfilled in conjunction with ground networks.

Kriegl, W.; Laufenberg, W.

1980-09-01

169

Engineering calculations for communications satellite systems planning  

NASA Technical Reports Server (NTRS)

Computer-based techniques for optimizing communications-satellite orbit and frequency assignments are discussed. A gradient-search code was tested against a BSS scenario derived from the RARC-83 data. Improvement was obtained, but each iteration requires about 50 minutes of IBM-3081 CPU time. Gradient-search experiments on a small FSS test problem, consisting of a single service area served by 8 satellites, showed quickest convergence when the satellites were all initially placed near the center of the available orbital arc with moderate spacing. A transformation technique is proposed for investigating the surface topography of the objective function used in the gradient-search method. A new synthesis approach is based on transforming single-entry interference constraints into corresponding constraints on satellite spacings. These constraints are used with linear objective functions to formulate the co-channel orbital assignment task as a linear-programming (LP) problem or mixed integer programming (MIP) problem. Globally optimal solutions are always found with the MIP problems, but not necessarily with the LP problems. The MIP solutions can be used to evaluate the quality of the LP solutions. The initial results are very encouraging.

Reilly, C. H.; Levis, C. A.; Mount-Campbell, C.; Gonsalvez, D. J.; Wang, C. W.; Yamamura, Y.

1985-01-01

170

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

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

171

Satellite fixed communications service: A forecast of potential domestic demand through the year 2000. Volume 3: Appendices  

NASA Technical Reports Server (NTRS)

Voice applications, data applications, video applications, impacted baseline forecasts, market distribution model, net long haul forecasts, trunking earth station definition and costs, trunking space segment cost, trunking entrance/exit links, trunking network costs and crossover distances with terrestrial tariffs, net addressable forecasts, capacity requirements, improving spectrum utilization, satellite system market development, and the 30/20 net accessible market are considered.

Kratochvil, D.; Bowyer, J.; Bhushan, C.; Steinnagel, K.; Kaushal, D.; Al-Kinani, G.

1983-01-01

172

Satellite services handbook. Interface guidelines  

NASA Technical Reports Server (NTRS)

Satellite interfaces for on orbit servicing, both manned and unmanned are identified, and is intended to be used by designers of space vehicles, both foreign and domestic. A primary concern is for design of interfaces with the astronaut in the loop, especially extravehicular activity, but also intravehicular activity and operations that are remote but have man-in-the-loop. The main emphasis is on servicing in low earth orbits from the Space Shuttle and also from the Space Station or other platforms.

1983-01-01

173

Satellite services handbook. Interface guidelines  

NASA Astrophysics Data System (ADS)

Satellite interfaces for on orbit servicing, both manned and unmanned are identified, and is intended to be used by designers of space vehicles, both foreign and domestic. A primary concern is for design of interfaces with the astronaut in the loop, especially extravehicular activity, but also intravehicular activity and operations that are remote but have man-in-the-loop. The main emphasis is on servicing in low earth orbits from the Space Shuttle and also from the Space Station or other platforms.

1983-12-01

174

Emergency Medical Services Communications Systems.  

National Technical Information Service (NTIS)

A booklet on emergency medical services (EMS) communications systems is presented as an aid for communities interested in developing a communications network to serve their emergency medical care needs. The material is intended for use by persons with som...

1972-01-01

175

NASA Compendium of Satellite Communications Programs  

NASA Technical Reports Server (NTRS)

A comprehensive review is presented of worldwide communication programs that range in time from the inception of satellite communications to August 1971. The programs included are: Echo, Courier, West Ford, Telstar, Relay, Syncom, Lincoln experimental satellites, Intelsat, Tacsat, Skynet, Nato system, and Telesat.

1973-01-01

176

Federal Research and Development for Satellite Communications.  

ERIC Educational Resources Information Center

This report of the Committee on Satellite Communications (COSC) reviews a number of future communication needs which could be satisfied by satellite systems, including needs in fields such as education, health care delivery, hazard warning, navigation aids, search and rescue, electronic mail delivery, time and frequency dissemination, and…

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

177

Satellite Services Handbook. Interface Guidelines.  

National Technical Information Service (NTIS)

Satellite interfaces for on orbit servicing, both manned and unmanned are identified, and is intended to be used by designers of space vehicles, both foreign and domestic. A primary concern is for design of interfaces with the astronaut in the loop, espec...

1983-01-01

178

Satellite services and orbital retrieval  

NASA Technical Reports Server (NTRS)

Within the capabilities of the Space Shuttle Orbiter, a broad range of services which can be made available to the satellite user community as summarized. Payload deployment, close proximity retrieval, and a number of other mission related functions are discussed. The focus here is on close proximity retrieval and retrieval of payloads in higher energy low Earth orbits.

Adornato, R. J.

1985-01-01

179

NASA compendium of satellite communications programs  

NASA Technical Reports Server (NTRS)

A comprehensive review is given of worldwide satellite communication programs that range in time from the inception of satellite communications to mid-1974. Particular emphasis is placed on program results, including experiments conducted, communications system operational performance, and technology employed. The background for understanding these results is established through brief summaries of the program organization, system configuration, and satellite and ground terminal characteristics. Major consideration is given to the communications system aspects of each program, but general spacecraft technology and other experiments conducted as part of the same program are mentioned summarily.

1975-01-01

180

Communications satellites - Looking to the 1980s  

Microsoft Academic Search

Areas of technology likely to have an impact on communications satellite networks of the 1980s are discussed; the topics include launch vehicles and satellite 'buses', antennae design, on-board processing, two-way communications between satellites, multiple access systems, bit-error rate of digital transmission channels, digital voice processing techniques, and interface operations such as formatting, signaling, multiplexing and buffering. Intersatellite links in the

H. L. van Trees; E. V. Hoversten; T. P. McGarty

1977-01-01

181

Space industrialization - Education. [via communication satellites  

NASA Technical Reports Server (NTRS)

The components of an educational system based on, and perhaps enhanced by, space industrialization communications technology are considered. Satellite technology has introduced a synoptic distribution system for various transmittable educational media. The cost of communications satellite distribution for educational programming has been high. It has, therefore, been proposed to utilize Space Shuttle related technology and Large Space Structures (LSS) to construct a system with a quantum advancement in communication capability and a quantum reduction in user cost. LSS for communications purposes have three basic advantages for both developed and emerging nations, including the ability to distribute signals over wide geographic areas, the reduced cost of satellite communications systems versus installation of land based systems, and the ability of a communication satellite system to create instant educational networks.

Joels, K. M.

1978-01-01

182

Inmarsat and personal mobile satellite services  

NASA Astrophysics Data System (ADS)

Personal communications - mobile satellite services (PC-MSS) hold much promise as a profitable business opportunity for a number of interested operators and manufacturers. What will be their impact on the overall mobile communications landscape, and what role will they play in the drive towards the universal personal communicator? It is the thesis of this paper that PC-MSS can provide one of the critical enabling technologies to allow a more rapid, global assimilation of personal mobile communications. Terrestrial mobile communications are local by definition, both in terms of service reach and regulatory oversight. It is estimated that cellular, and other forms of terrestrial mobile communications, will cover over 50% of the world's population, but only 15% of the land mass area by the year 2000. PC-MSS will allow 'cellular extension' to interested users in the uncovered parts of the world. The market opportunity is established and technical solutions are available. However 'user cooperation' will be required and cross mapping of market needs to the technology solutions is the key to financially viable solutions. The potential political and regulatory hurdles are daunting. Inmarsat, as the existing global MSS partnership, is already introducing PC-MSS products and services in the 1990s. The widespread use of briefcase satphones (Inm-M), laptop-sized data terminals (Inm-C), and pocket satpagers (Inm-paging) will break new ground in reshaping the international regulatory context of mobile communications, and in initiating the optimal public switched network integration necessary for global interconnect. It is suggested that this evolutionary approach, by means of international consensus-building within a global partnership of operators, is an effective and proven method to ensure both a sufficient financial return for investors, and fair and equitable access of these services for all countries and users.

McDougal, Patrick; Barendse, Victor

183

Satellite-aided mobile communications, experiments, applications and prospects  

NASA Technical Reports Server (NTRS)

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

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

1980-01-01

184

Keep in Touch: Communications and Satellites  

NSDL National Science Digital Library

How do we communicate with each other? How do we communicate with people who are close by? How do we communicate with people who are far away? In this lesson, students will explore the role of communications and how satellites help people communicate with others far away and in remote areas with nothing around (i.e., no obvious telecommunications equipment). Students will learn about how engineers design satellites to benefit life on Earth. This lesson also introduces the theme of the rockets curricular unit.

Integrated Teaching And Learning Program

185

Economics of satellite communications systems  

NASA Astrophysics Data System (ADS)

This paper is partly a tutorial, telling systematically how one goes about calculating the total annual costs of a satellite communications system, and partly the expression of some original ideas on the choice of parameters so as to minimize these costs. The calculation of costs can be divided into two broad categories. The first is technical and is concerned with estimating what particular equipment will cost and what will be the annual expense to maintain and operate it. One starts in the estimation of any new system by listing the principal items of equipment, such as satellites, earth stations of various sizes and functions, telemetry and tracking equipment and terrestrial interfaces, and then estimating how much each item will cost. Methods are presented for generating such estimates, based on a knowledge of the gross parameters, such as antenna size, coverage area, transmitter power and information rate. These parameters determine the system performance and it is usually possible, knowing them, to estimate the costs of the equipment rather well. Some formulae based on regression analyses are presented. Methods are then given for estimating closely related expenses, such as maintenance and operation, and then an approximate method is developed for estimating terrestrial interconnection costs. It is pointed out that in specific cases when tariff and geographical information are available, it is usually better to work with specific data, but nonetheless it is often desirable, especially in global system estimating, to approximate these interconnect costs without recourse to individual tariffs. The procedure results in a set of costs for the purchase of equipment and its maintenance, and a schedule of payments. Some payments will be incurred during the manufacture of the satellite and before any systems operation, but many will not be incurred until the system is no longer in use, e.g. incentives. In any case, with the methods presented in the first section, one arrives at a schedule of costs and payments for all the items and the years in which they will be incurred. The second category of costing problems is one of financing or engineering economics. All the costs are first "present valued" to some reference period using rates of return appropriate to the particular situation. One finally arrives at sets of annual costs which can be used as the basis for setting lease costs or revenue requirements and tariffs. The correspondence between methods using discounted rates of return and capital recovery formulae on one hand and those using various depreciation schedules, such as is typical of regulated industries on the other hand, is discussed. The remainder of the paper is devoted to discussing the relationship between critical parameters, such as replacement schedules, design lifetime, satellite power and Earth station antenna size, and the overall costs. It is shown that optima for these parameters may exist and can be calculated. In particular, the optimization of satellite replacement schedules to minimize the present value of total investment over a very long period is presented, along with simplified versions of the theory suitable for system planning. The choice of EIRP is also discussed and a procedure for choosing the value that minimizes the costs is shown.

Pritchard, Wilbur L.

186

Interim Service ISDN Satellite (ISIS) hardware experiment design for advanced ISDN satellite design and experiments  

NASA Technical Reports Server (NTRS)

The Interim Service Integrated Services Digital Network (ISDN) Satellite (ISIS) Hardware Experiment Design for Advanced Satellite Designs describes the design of the ISDN Satellite Terminal Adapter (ISTA) capable of translating ISDN protocol traffic into time division multiple access (TDMA) signals for use by a communications satellite. The ISTA connects the Type 1 Network Termination (NT1) via the U-interface on the line termination side of the CPE to the V.35 interface for satellite uplink. The same ISTA converts in the opposite direction the V.35 to U-interface data with a simple switch setting.

Pepin, Gerard R.

1992-01-01

187

Interim Service ISDN Satellite (ISIS) hardware experiment development for advanced ISDN satellite designs and experiments  

NASA Technical Reports Server (NTRS)

The Interim Service Integrated Service Digital Network (ISDN) Satellite (ISIS) Hardware Experiment Development for Advanced Satellite Designs describes the development of the ISDN Satellite Terminal Adapter (ISTA) capable of translating ISDN protocol traffic into Time Division Multiple Access (TDMA) signals for use by a communications satellite. The ISTA connects the Type 1 Network Termination (NT1) via the U-interface on the line termination side of the CPE to the RS-499 interface for satellite uplink. The same ISTA converts in the opposite direction the RS-499 to U-interface data with a simple switch setting.

Pepin, Gerard R.

1992-01-01

188

Satellite communications in Europe - The earth-segment market  

NASA Astrophysics Data System (ADS)

The earth segment market of the new European satellite telecommunications field is projected for the next decade, and suggestions are made for its improvement. The home market for large Eutelsat stations (comprising the international telephone and television exchanges) is being dominated by the Japanese industry. Small station fixed satellite services (including business multiservices, distribution of CATV and SMATV, and the distribution of information to closed user groups) could create a substantial market for European industry with the relaxation of regulatory restraints. Four high-power satellites currently under development will open a market in direct broadcasting (DBS). Although the potential for mobile-satellite services (land mobile and maritime communications) is great, the European industry possesses only 15 percent of the present Inmarsat ship-terminal market. It is concluded that European industrial competitiveness could be increased by a general telecommunications policy for regulation, standardization, and research. Tables summarizing the telecommunications service potential and the satellite transponders available for TV distribution, are included.

Bartholome, P.; Hughes, C. D.

1985-11-01

189

Communications satellites - Orbiting into the '90s  

NASA Astrophysics Data System (ADS)

Engineering advances in satellite communications are discussed, including sophisticated switchboards, narrow beams, source coding for higher-capacity networks, and the use of higher- and lower-frequency bands and lower orbits. One of the most popular new 14/11-14/12-GHz commercial services has been time-division multiplexing of multiple carriers operating at low to medium bit rates. Multiple-carrier, low-burst-rate TDMA is widely used with VSATs on the customer's premises. NASA's ACTS and Italy's Italsat both plan to use signal regeneration at 30/20 GHz. Onboard switching and multiplexing minimize noise, boost power, but also trim the cost of the entire satellite network. Phone calls and voiceband data are now often carried over satellite circuits and by cable beneath the ocean by adaptive differential pulse-coded modulation (ADPCM). When this technique at 32 kb/s is combined with digital speech interpolation, circuits can carry 4-5 times as many channels as with conventional 64-kb/s pulse-coded transmission.

Campanella, S. Joseph

1990-08-01

190

A model for evaluating communications satellite interoperability  

NASA Astrophysics Data System (ADS)

A model with which emergency communications planners can evaluate the potential interoperability of satellite systems is described. Based on minimum communications requirements set forth by the Commercial Satellite Survivability Task Force of the National Telecommunications Advisory Committee, the model addresses the technical considerations involved in system interoperability and provides the basis for further study. This paper addresses the need for finding techniques to implement an interoperable network of commercial satellites to augment our national security/emergency preparedness communications. Commercial satellite networks play an increasingly important role in providing essential communications during peacetime. They offer the means to quickly restore damaged or destroyed communications to isolated parts of the country during times of national security stress. However, the use of different technical methods by system operators presents major roadblocks to network interoperability.

Gill, T. C.

191

Broadcast satellite service: The international dimension  

NASA Technical Reports Server (NTRS)

The dawn of the 1990's has witnessed the birth of a new satellite service - satellite sound broadcasting. This new service is characterized by digital transmission at data rates up to 256 kb/s from satellites in geostationary orbit to small, low-cost, mobile and portable receivers. The satellite sound broadcasting service is a logical step beyond navigation satellite service, such as that provided by the GPS Navstar system. The mass market appeal of satellite sound broadcasting in the area of lightsat technology and low-cost digital radios has greatly facilitated the financing of this type of space service.

Samara, Noah

1991-01-01

192

Satellite servicing: A business opportunity?  

NASA Technical Reports Server (NTRS)

The possibilities of satellite servicing as a business opportunity are examined. The service rate which a user must be charged to yield a reasonable return is derived and then compared against the market's willingness to pay that rate. Steps taken to provide the basis from which the service rate could be derived include: (1) constructing a hypothetical on orbit servicing business offering both on orbit and associated ground services; (2) estimating the total on orbit service business potential by analyzing mission models to the year 2000; and (3) setting up ground rules to bound the conduct of the business. Using this basic information service demand (business volume) cost to set up the business, costs for operation and maintenance tax rates and desired rate of return are estimated to determine the user charge. Sensitivity of the service rate to various parameters are also assessed. The time span for the business venture runs from 1986 through 2000 with service to 1991 provided via the orbiter and by a space station beyond 1991. This point analysis shows about five years of negative cash flow, with steady profits thereafter.

Wong, R. E.; Medler, E. H.

1984-01-01

193

Analysis of maritime mobile satellite communication systems  

NASA Astrophysics Data System (ADS)

The communication channel between a satellite and a ship earth station (SES) is described by a model which includes multipath fading, Doppler shift and noise. Multipath fading is caused by reflections from the sea surface. These reflections can affect the system performance, especially at low elevation angles or when SES is using low gain antennas. Doppler shift is a very important effect when using low altitude satellites, because of the high velocities involved. A software simulator is described and a simulator is presented for multipath fading in the maritime communications environment. Analysis of throughput of an unslotted Aloha maritime mobile satellite communication channel is also presented.

Zapata, Augusto J.

1988-12-01

194

Program on application of communications satellites to educational development  

NASA Technical Reports Server (NTRS)

Interdisciplinary research in needs analysis, communications technology studies, and systems synthesis is reported. Existing and planned educational telecommunications services are studied and library utilization of telecommunications is described. Preliminary estimates are presented of ranges of utilization of educational telecommunications services for 1975 and 1985; instructional and public television, computer-aided instruction, computing resources, and information resource sharing for various educational levels and purposes. Communications technology studies include transmission schemes for still-picture television, use of Gunn effect devices, and TV receiver front ends for direct satellite reception at 12 GHz. Two major studies in the systems synthesis project concern (1) organizational and administrative aspects of a large-scale instructional satellite system to be used with schools and (2) an analysis of future development of instructional television, with emphasis on the use of video tape recorders and cable television. A communications satellite system synthesis program developed for NASA is now operational on the university IBM 360-50 computer.

Morgan, R. P.; Singh, J. P.

1971-01-01

195

Engineering calculations for communications satellite systems planning  

NASA Technical Reports Server (NTRS)

An extended gradient search code for broadcasting satellite service (BSS) spectrum/orbit assignment synthesis is discussed. Progress is also reported on both single-entry and full synthesis computational aids for fixed satellite service (FSS) spectrum/orbit assignment purposes.

Levis, C. A.; Martin, C. H.; Reilly, C. H.; Gonsalvez, D. J.; Yamaura, Y.

1985-01-01

196

Spacecraft design project: High latitude communications satellite  

NASA Technical Reports Server (NTRS)

The spacecraft design project was part of AE-4871, Advanced Spacecraft Design. The project was intended to provide experience in the design of all major components of a satellite. Each member of the class was given primary responsibility for a subsystem or design support function. Support was requested from the Naval Research Laboratory to augment the Naval Postgraduate School faculty. Analysis and design of each subsystem was done to the extent possible within the constraints of an eleven week quarter and the design facilities (hardware and software) available. The project team chose to evaluate the design of a high latitude communications satellite as representative of the design issues and tradeoffs necessary for a wide range of satellites. The High-Latitude Communications Satellite (HILACS) will provide a continuous UHF communications link between stations located north of the region covered by geosynchronous communications satellites, i.e., the area above approximately 60 N latitude. HILACS will also provide a communications link to stations below 60 N via a relay Net Control Station (NCS), which is located with access to both the HILACS and geosynchronous communications satellites. The communications payload will operate only for that portion of the orbit necessary to provide specified coverage.

Josefson, Carl; Myers, Jack; Cloutier, Mike; Paluszek, Steve; Michael, Gerry; Hunter, Dan; Sakoda, Dan; Walters, Wes; Johnson, Dennis; Bauer, Terry

1989-01-01

197

Analysis of Maritime Mobile Satellite Communication Systems.  

National Technical Information Service (NTIS)

The communication channel between a satellite and a ship earth station (SES) is described by a model which includes multipath fading, doppler shift and noise. Multipath fading is caused by reflections from the sea surface. These reflections can affect the...

A. J. Zapata

1988-01-01

198

Present and future trends in military satellite communication systems  

Microsoft Academic Search

Recent years have seen a phenomenal growth in the field of satellite communications. Satcom systems offer many advantages for military applications which include wide area coverage, rapid deployment, flexible networking and long range service to moving platforms like ships, aircraft and vehicles. This paper gives an overview of the special features and future trends in military satcom systems. A brief

C. K. Chatterjee; Surendra Pal

1993-01-01

199

A figure of merit for competing communications satellite designs  

NASA Technical Reports Server (NTRS)

Trends in launch schedules, weights, power, and space segment costs per transponder year for Intelsats and North American domsats (domestic communications satellites) are discussed. The Intelsat system currently services 25,000 point to point telephone links at any one moment, and a $3 billion order has been placed for Intelsat VIs, which feature 36,000 telephone circuits each. The Intelsat VI spacecraft will weigh 1670 kg in orbit, a continuance of the trend to heavier satellites, while the domsats will stay at 650 kg due to launch vehicle limitations. Direct television broadcast satellites are being designed for receive only (R/O) earth stations, with each satellite capable of servicing 50,000 individual ground stations. Competition is growing for C and Ku band satellite transponders for DBS, with costs $350,000 each. No standardized design has yet emerged.

Lovell, R. R.; Fordyce, S. W.

1983-01-01

200

Developments in land mobile satellite service in Europe  

NASA Technical Reports Server (NTRS)

The evolution of land mobile radio has reached a stage to benefit from satellite communications. The provision of a service on a pan-European basis makes the use of satellites a viable proposition. The paper describes the European position on both system and space segment aspects of the land mobile satellite service. Also, some of the functions of the European institutions, such as the European Telecommunications Standards Institute (ETSI), the Conference of European Postal and Telecommunications Administrations (CEPT), and the Commission of European Communities (CEC), in establishing these services are identified.

Jayasuriya, D. A. R.

1990-01-01

201

Advances in multibeam communications satellite antennas  

Microsoft Academic Search

The evolution of satellite antennas over the past quarter of a century is presented. Five major areas of advances in communications satellite antenna technology are reviewed: single offset reflectors with feed arrays, shaped reflector systems, active phased arrays, phased-array-fed dual reflector systems, and lightweight feed elements. Examples are given of existing systems and of the ongoing development of new technologies.

Amir I. Zaghloul; Robert M. Sorbello; Francois T. Assal; Yeongming Hwang

1990-01-01

202

Advances in multibeam communications satellite antennas  

Microsoft Academic Search

The evolution of satellite antennas over the past quarter of a century is presented. Five major areas of advances in communications satellite antenna technology are reviewed: single offset reflectors with feed arrays, shaped reflector systems, active phased arrays, phased-array-fed dual reflector systems, and lightweight feed elements. Examples are given of existing systems and of the ongoing development of new technologies

A. I. Zaghloul; Y. Hwang; R. M. Sorbello; F. T. Assal

1990-01-01

203

High accuracy deployable antenna for communications satellite  

Microsoft Academic Search

High frequency multi-beam satellite antennas have been studied to realize increased communication capacity, simplified earth stations, and multiple frequency reuse. The satellite antenna needs a highly accurate and large reflector. To overcome the launching vehicle's constraints in size and weight, a solid deployable antenna is under development. A petal antenna (PETAL), composed of solid shell elements, has been studied as

M. Watanabe; M. Misawa; M. Minomo; T. Yasaka

1982-01-01

204

Narrow-Band Applications of Communications Satellites.  

ERIC Educational Resources Information Center

This paper attempts to describe the advantages of "narrow-band" applications of communications satellites for education. It begins by discussing the general controversy surrounding the use of satellites in education, by placing the concern within the larger context of the general debate over the uses of new technologies in education, and by…

Cowlan, Bert; Horowitz, Andrew

205

Large communications platforms versus smaller satellites  

NASA Technical Reports Server (NTRS)

Communications systems using large platforms are compared with systems using conventional satellites. Systems models were generated and compared for U.S. domestic application and for 1 INTELSAT's international and domestic transponder lease application. Technology advances were assumed the platforms and the evolution of conventional satellites.

1979-01-01

206

Low Earth Orbit satellite/terrestrial mobile service compatibility  

NASA Technical Reports Server (NTRS)

Currently the geostationary type of satellite is the only one used to provide commercial mobile-satellite communication services. Low earth orbit (LEO) satellite systems are now being proposed as a future alternative. By the implementation of LEO satellite systems, predicted at between 5 and 8 years time, mobile space/terrestrial technology will have progressed to the third generation stage of development. This paper considers the system issues that will need to be addressed when developing a dual mode terminal, enabling access to both terrestrial and LEO satellite systems.

Sheriff, Ray E.; Gardiner, John G.

1993-01-01

207

Millimeter-wave personal satellite communication system  

NASA Astrophysics Data System (ADS)

This paper describes the system concept of a millimeter-wave personal satellite communication, which includes the configuration of the communication system, the satellite system, and the earth terminal system. The system has a large channel capacity and achieves high performance through a flexible channel set-up method, efficient frequency reuse, and onboard communication equipment such as a baseband channel switching processor and a modulator and demodulator (Modem). Two examples of communication systems are shown, in which the information bit rate, the number of multi-beams, and the antenna diameters are different. On the assumption that a 2 ton class satellite will be used, rough estimates are made of the size, weight, and power consumption of the onboard communication system and bus system of the satellite. In addition, details are given regarding the specifications and performance of trial productions of communication equipment such as the switching processor, the Modem, the TWTA, and the LNA. Finally, the key technical issues for establishing a millimeter-wave personal satellite communication system are also discussed.

Kashiki, Kanshiro; Kuri, Takaki; Maruyama, Hideyuki; Kikuchi, Takaaki; Yamamoto, Tetsuo

1993-10-01

208

Millimeter-wave personal satellite communication system  

NASA Astrophysics Data System (ADS)

This paper describes the system concept of a millimeter-wave personal satellite communication, which includes the configuration of the communication system, the satellite system, and the earth terminal system. The system has a large channel capacity and achieves high performance through a flexible channel set-up method, efficient frequency reuse, and onboard communication equipment such as a baseband channel switching processor and a modulator and demodulator (Modem). Two examples of communication systems are shown, in which the information bit rate, the number of multi-beams, and the antenna diameters are different. On the assumption that a 2 ton class satellite will be used, rough estimates are made of the size, weight, and power consumption of the onboard communication system and bus system of the satellite. In addition, details are given regarding the specifications and performance of trial productions of communication equipment such as the switching processor, the Modem, the TWTA, and the LNA. Finally, the key technical issues for establishing a millimeter-wave personal satellite communication system are also discussed.

Kashiki, Kanshiro; Kuri, Takaki; Maruyama, Hideyuki; Kikuchi, Takaaki; Yamamoto, Tetsuo

209

Packet radio in the amateur satellite service  

NASA Astrophysics Data System (ADS)

A review of the satellite-based packet radio activities taking place in the Amateur Radio Service is presented. Five projects are discussed. The Digital Communications Experiment (DCE) on Uosat OSCAR-11 is a store-and-forward system that is accessed by a limited number of stations around the world designated as DCE gateways. These gateway stations retrieve and store messages forwarded to them via terrestrial packet radio networks. The Japanese FO-12 satellite is a store-and-forward system, and its user interface is much like computer bulletin boards accessed via land lines. It is available for use by all radio amateurs with the required equipment. Both UO-11 and FO-12 are in LEO.

Diersing, Robert J.; Ward, Jeffrey W.

1989-02-01

210

Reconfigurability in future communication satellite systems  

NASA Astrophysics Data System (ADS)

Reconfigurability in the Broadcasting Satellite Service (BSS) and in the Fixed Satellite Service (FSS) is examined. The use in BSS of a common spare for different European national satellites is addressed, showing the feasibility of this solution for a system with three satellites in orbit. Solutions involving a repointable antenna with few feed horns and a fixed antenna with more feed horns are described. The use in FSS of a European system at Ku band for the latter 1990s is considered, describing a simplified reconfigurable FSS transmit front end.

Berretta, G.; Roederer, A.

211

Continuation of the compendium of applications technology satellite and communications technology satellite user experiments 1967-1977, volume 1  

NASA Technical Reports Server (NTRS)

User experiments conducted utilizing the Applications Technology Satellites (ATS) 1, 3, 5, and 6 and the Communications Technology Satellite are summarized. The experiments are grouped by type of service offered. For example: education, health services, and data transmission. Particular emphasis is given to summarizing and evaluating user attitudes toward the ATS program.

Engler, N. A.; Nash, J. F.; Strange, J. D.

1978-01-01

212

Geostationary payload concepts for personal satellite communications  

NASA Technical Reports Server (NTRS)

This paper reviews candidate satellite payload architectures for systems providing world-wide communication services to mobile users equipped with hand-held terminals based on large geostationary satellites. There are a number of problems related to the payload architecture, on-board routing and beamforming, and the design of the S-band Tx and L-band Rx antenna and front ends. A number of solutions are outlined, based on trade-offs with respect to the most significant performance parameters such as capacity, G/T, flexibility of routing traffic to beams and re-configuration of the spot-beam coverage, and payload mass and power. Candidate antenna and front-end configurations were studied, in particular direct radiating arrays, arrays magnified by a reflector and active focused reflectors with overlapping feed clusters for both transmit (multimax) and receive (beam synthesis). Regarding the on-board routing and beamforming sub-systems, analog techniques based on banks of SAW filters, FET or CMOS switches and cross-bar fixed and variable beamforming are compared with a hybrid analog/digital approach based on Chirp Fourier Transform (CFT) demultiplexer combined with digital beamforming or a fully digital processor implementation, also based on CFT demultiplexing.

Benedicto, J.; Rinous, P.; Roberts, I.; Roederer, A.; Stojkovic, I.

1993-01-01

213

Geostationary payload concepts for personal satellite communications  

NASA Astrophysics Data System (ADS)

This paper reviews candidate satellite payload architectures for systems providing world-wide communication services to mobile users equipped with hand-held terminals based on large geostationary satellites. There are a number of problems related to the payload architecture, on-board routing and beamforming, and the design of the S-band Tx and L-band Rx antenna and front ends. A number of solutions are outlined, based on trade-offs with respect to the most significant performance parameters such as capacity, G/T, flexibility of routing traffic to beams and re-configuration of the spot-beam coverage, and payload mass and power. Candidate antenna and front-end configurations were studied, in particular direct radiating arrays, arrays magnified by a reflector and active focused reflectors with overlapping feed clusters for both transmit (multimax) and receive (beam synthesis). Regarding the on-board routing and beamforming sub-systems, analog techniques based on banks of SAW filters, FET or CMOS switches and cross-bar fixed and variable beamforming are compared with a hybrid analog/digital approach based on Chirp Fourier Transform (CFT) demultiplexer combined with digital beamforming or a fully digital processor implementation, also based on CFT demultiplexing.

Benedicto, J.; Rinous, P.; Roberts, I.; Roederer, A.; Stojkovic, I.

214

Adaptive multibeam satellite communications using active array  

Microsoft Academic Search

A multiple beam satellite communications system which can adaptively allocate communications capacity to each beam is proposed. Using an active array as a multibeam transmitting antenna, it becomes unnecessary to assume fixed transponders or a fixed transmission capacity to each beam, enabling the adaptive allocation of transmission capacity. In order to facilitate the beam forming network design, space-fed type array

S. Egami; M. Kawai

1984-01-01

215

Apple - Indian experimental geostationary communication satellite  

Microsoft Academic Search

Developmental steps, responsibilities, design goals, performance characteristics, and support systems for the ISRO Ariane Passenger Payload Experiment (APPLE) experimental GEO communication satellite are described. The spacecraft underwent structural, thermal, engineering, prototype, and flight qualification tests in India before being shipped to Guyana for launch on the third Ariane test flight. APPLE carries a redundant C-band communication transponder fed by a

U. R. Rao; R. M. Vasagam

1982-01-01

216

Satellite Communications in the 1980's.  

ERIC Educational Resources Information Center

Space communications have developed tremendously since 1963 when the National Aeronautics and Space Administration (NASA) launched the synchronous communication satellite, Syncom II, into geostationary orbit. The capacity of that spacecraft was one two-circuit voice channel. Intelsat V, launched in 1980, has a capacity of 12,000 circuits plus two…

Usunier, Pierre

217

An Educator's Guide to Communication Satellite Technology.  

ERIC Educational Resources Information Center

Recent developments in the area of sophisticated communications technology present challenges to the imagination of every educator. This guide provides educational planners with an awareness and understanding of communication satellite technology, its current uses, and some of the tentative plans for educational experimentation. The first part…

Polcyn, Kenneth A.

218

A small terminal for satellite communication systems  

NASA Technical Reports Server (NTRS)

A small portable, low-cost satellite communications terminal system incorporating a modulator/demodulator and convolutional-Viterbi coder/decoder is described. Advances in signal processing and error-correction techniques in combination with higher power and higher frequencies aboard satellites allow for more efficient use of the space segment. This makes it possible to design small economical earth stations. The Advanced Communications Technology Satellite (ACTS) was chosen to test the system. ACTS, operating at the Ka band incorporates higher power, higher frequency, frequency and spatial reuse using spot beams and polarization.

Xiong, Fuqin; Wu, Dong; Jin, Min

1994-01-01

219

Satellite multiple access systems for mobile communication  

NASA Technical Reports Server (NTRS)

This paper considers multiple access techniques for a mobile radio system which incorporates a geosynchronous orbiting satellite repeater through which mobile terminals communicate. The communication capacities of FDMA, TDMA and CDMA systems are examined for a 4 MHz bandwidth system to serve up to 10,000 users. An FDMA system with multibeam coverage is analyzed in detail. The system includes an order-wire network for demand-access control and reassignment of satellite channels. Satellite and terminal configurations are developed to a block diagram level and system costs and implementation requirements are discussed.

Lewis, J. L.

1979-01-01

220

Explanatory information for news conference on satellite communications  

NASA Technical Reports Server (NTRS)

The CS-2 communications satellite which has features such as frequencies of the 30/20GHz band, demand assign time division multiple access, improved ship-to-satellite communications methods, and multibeam satellite communications methods. Research is continuing towards the production of larger, more economical communication systems via satellite which have greater efficiency and capacity.

1983-01-01

221

Satellite communications systems and technology. Volume 1: Analytical chapters  

Microsoft Academic Search

This is Volume 1 (Analytical Chapters) of the final report of the NASA\\/NSF Panel Satellite Communications Systems and Technology. The panel surveyed advanced technology being developed for commercial use in the satellite communications field in Europe, Japan, and Russia. All aspects of satellite communications were considered, including fixed, broadcast, mobile, personal communications, navigation, low earth orbit, and small satellites. The

Burton I. Edelson; Joseph N. Pelton; Charles W. Bostian; William T. Brandon; Vincent W. S. Chan; E. Paul Hager; Neil R. Helm; Raymond D. Jennings; Robert K. Kwan; Christoph E. Mahle

1993-01-01

222

High thermally conductive communications equipment panel module for communications satellite  

Microsoft Academic Search

A new communications equipment panel module for satellite use has been developed to obtain a high thermal conductivity across the thickness in transversal direction of the panel. As the conventional communications equipment panel has a sandwich structure with aluminum-alloy face sheets and a honeycomb core, the transversal thermal conductivity is relatively small, mainly due to epoxy resin adhesive layers between

Akio Iso; Mitsunobu Watanabe; Hiroaki Tsunoda

1986-01-01

223

The Globalstar mobile satellite system for worldwide personal communications  

NASA Technical Reports Server (NTRS)

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

Wiedeman, Robert A.; Viterbi, Andrew J.

1993-01-01

224

Annual Survey of Communication Services  

NSDL National Science Digital Library

The Census Bureau has released findings for selected United States communications industry groups from 1995 to 1996. Telephone communication revenues showed an increase of 10 percent while radio and television broadcasting services increased 9 percent. Cable and other pay television services grew the most in 1996 with total revenues of $38 Billion at an increase of 14 percent. Overall, the industry boomed in 1996 with revenues of more than $322 billion.

225

The use of satellites in non-goestationary orbits for unloading geostationary communication satellite traffic peaks. Volume 2: Technical report  

NASA Technical Reports Server (NTRS)

The part of the geostationary (GEO) orbital arc used for United States domestic fixed, communications service is rapidly becoming filled with satellites. One of the factors currently limiting its utilization is that communications satellites must be designed to have sufficient capacity to handle peak traffic leads, and thus are under utilized most of the time. A solution is to use satellites in suitable non-geostationary orbits to unload the traffic peaks. Three different designs for a non-geostationary orbit communications satellite system are presented for the 1995 time frame. The economic performance is analyzed and compared with geostationary satellites for two classes of service, trunking and customer premise service. The result is that the larger payload of the non-geostationary satellite offsets the burdens of increased complexity and worse radiation environment to give improved economic performance. Depending on ground terminal configuration, the improved economic performance of the space segment may be offset by increased ground terminal expenses.

Price, K.; Turner, A.; Nguyen, T.; Doong, W.; Weyandt, C.

1987-01-01

226

Channel Modelling and Characterization of Mobile Satellite Communication Systems  

NASA Astrophysics Data System (ADS)

Reliable characterization of the propagation environment and channel modelling of mobile satellite communication systems is necessary in order to provide better quality of service and efficient design of these systems. In this paper, the channel impairments affecting the performance and an overview of the satellite channel models are presented. The statistical distributions of the received signal that can be used to characterize the dynamic nature of these propagation channels are also presented. The main modelling parameters are investigated and simulation results show that the bit error rate (BER) performance is predominantly affected by the shadowing factor. Finally, in order to further test the channel models and the effect of the propagation environment, we investigate a novel application of using satellite diversity in conjunction with compact MIMO (multiple-input multiple-output) antenna array configurations in order to enhance the capacity of satellite communication links.

Mohammed, Abbas; Seun, Ajayi; Yang, Zhe; Erman, Maria; Hult, Tommy

2009-03-01

227

Aeronautical Mobile Satellite Service (AMSS) Message and Voice Access Request Transit Delay.  

National Technical Information Service (NTIS)

The development of standards for the use of satellite communications in aviation is supported by FAA. A preliminary analysis and simulation of the Aeronautical Mobile Satellite Service (AMSS) were conducted to determine message transit delay of the system...

T. F. Dehel

1991-01-01

228

Texas Telecommunication Satellite Demonstration Project. Planning Effort for Application of Communication Satellites in Education.  

ERIC Educational Resources Information Center

The primary goal of the Texas Telecommunication Satellite Demonstration consortium is to install, operate, and evaluate a comprehensive communication service delivery system which would provide the citizens of Texas with greater opportunity for equal access to education and information. The four major objectives of the demonstration are (1) to…

Education Service Center Region 4, Houston, TX.

229

Mobile satellite communications - Applications for developing countries  

NASA Astrophysics Data System (ADS)

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

von Noorden, Wolf D.

230

Global disaster satellite communications system for disaster assessment and relief coordination  

NASA Technical Reports Server (NTRS)

The global communication requirements for disaster assistance and examines operationally feasible satellite system concepts and the associated system parameters are analyzed. Some potential problems associated with the current method of providing disaster assistance and a scenario for disaster assistance relying on satellite communications are described. Historical statistics are used with the scenario to assess service requirements. Both present and planned commercially available systems are considered. The associated global disaster communication yearly service costs are estimated.

Leroy, B. E.

1979-01-01

231

Engineers checkout Early Bird-Communication Satellite  

NASA Technical Reports Server (NTRS)

Engineers Stanley R. Peterson (left) and Ray Bowerman (right), checkout the Early Bird, the world's first communication satellite. NASA launched the satellite built by Hughes Aircraft Corporation on April 6, 1955 at 6:48pm E.S.T. from Complex 17a at Cape Kennedy, Florida. Early Bird was built for the Communications Satellite Corporation and weighed about 85 pounds after being placed in a synchronous orbit of 22,300 miles above the earth. It was positioned over the Atlantic to provide 240 two-way telephone channels or 2-way television between Europe and North America. The outer surface of Early Bird was covered with 6,000 silicon-coated solar cells, which absorbed the sun's rays to provide power to the satellite for its intricate transmitting and receiving equipment.

1984-01-01

232

Italsat - A step forward in communication satellites  

NASA Astrophysics Data System (ADS)

The communication satellite program, Italsat, is one of the main elements of the Piano Spaziale Nazionale, the Italian space research and development long term plan. The purpose of the Italsat experimental and preoperative mission is to anticipate most of the new techniques and solutions suitable for the next generation of domestic digital communication satellites, as well as to verify some new system concepts from technical and economical points of view. The paper gives a concise overview of the whole program, while offering a detailed description of the Italsat space segment, planned to be in orbit before the end of 1990.

Marconicchio, Franco; Morelli, Guido; Valdoni, Francesco

1988-12-01

233

Prediction of fading phenomena in land-satellite communication links  

NASA Astrophysics Data System (ADS)

This paper addresses the problem of prediction of probability of successful radio communication of any mobile or stationary subscriber located in areas of service such as complex urban environments characterized by nonline-of-sight propagation conditions, which limit GPS, Low Earth Orbit, and Medium Earth Orbit services in land-satellite communications. It presents a self-consistent physical-statistical approach for predicting fading phenomena usually occurring in land-satellite communication links caused by influence of the terrain features on radio signal propagation from the ground-based to the satellite antenna. This approach combines (1) the statistical description of the buildings array located on the rough terrain and the buildings' overlay profile, based on special probabilistic distributions of built-up terrain parameters, and (2) the theoretical description of propagation phenomena, taking into account multiple scattering, reflection, and diffraction mechanisms. A new technique is proposed for predicting the probability of fading phenomena occurring in land-satellite links using the so-called stochastic multiparametric model. Results of theoretical predictions are compared with those obtained from the "pure statistical" Lutz model and physical-statistical Saunders-Evans model, and then with experimental data obtained for different European cities. Obtained results show that the proposed stochastic approach can be used as a good predictor of fading phenomena in land-satellite communication links for different satellite constellation scenarios and elevations of satellites during their movement surrounding the Earth, with respect to the ground-based antenna for different land environments: rural, mixed residential, suburban, and urban.

Blaunstein, N.; Cohen, Y.; Hayakawa, M.

2010-12-01

234

Communication equipment technologies of Japanese domestic communication satellites  

NASA Astrophysics Data System (ADS)

Current and planned satellite technology for the Japanese domestic communication system is surveyed. The experimental CS and the operating commercial CS-2 satellites are briefly described, and the design of the CS-3 (to be launched in 1988) is examined. CS-3 weighs 550 kg and comprises 10 single-conversion 10-W TWTA K-band transponders covering the main islands of Japan and two FETA C-band transponders covering the entire territory of Japan; the total transmission capacity is 6000 channels. Multibeam configurations (using K and S bands) for increased transmission capacity are discussed in the light of preliminary studies of an information network system (to provide trunk transmission, digital business communication, and mobile communication) using a 2-4-ton 12-30-beam satellite. A capacity of 100,000-200,000 channels in the 30/20-GHz band is considered feasible for the 1990s.

Miyauchi, K.; Yamamoto, H.; Kondo, K.

235

African satellite communication systems and their implications  

NASA Astrophysics Data System (ADS)

Because of the size of the African continent and the, in general, poor conditions of its communication facilities, a number of solutions involving the use of satellites have been considered. The present investigation is concerned with the Afsat project. This project has been promoted and studied by Eurospace, which represents the Organization of the European Space Industry, founded in 1961. The current situation and needs of communication in Africa are considered along with a feasibility study of the system, the economic aspects, a comparison of Afsat with alternative solutions, and problems of space segment financing and organization. It is concluded that a dedicated African communication satellite system would make a decisive contribution to the improvement of the continent's communications in terms of increased capacity and better availability and quality of circuits.

Demerliac, Y.

1984-07-01

236

A satellite communications system for electric utilities  

NASA Technical Reports Server (NTRS)

This paper presents the results of a study into the feasibility of using satellite communications for a country-wide system of electric distribution system monitoring and control. The concept selected for study involves the use of a geostationary satellite with a large multi-beam antenna to provide a major part of the communications and control network between participating utilities and various elements of their power distribution networks, including customer loads. Electric utility communications requirements are projected through 1995 in order to size the required capacity of the system. Two basic systems are examined: a one-way system for load control, and a two-way system for distribution system monitoring and control, including customer meter reading. An operating protocol is proposed for each system. Preliminary cost estimates are identified element by element. Finally, expansion of the basic system to include a set of ancillary communications functions is briefly discussed.

Vaisnys, A.; Bergen, L.

1980-01-01

237

Deep space optical communication via relay satellite  

NASA Technical Reports Server (NTRS)

The application of optical communications for a deep space link via an earth-orbiting relay satellite is discussed. The system uses optical frequencies for the free-space channel and RF links for atmospheric transmission. The relay satellite is in geostationary orbit and contains the optics necessary for data processing and formatting. It returns the data to earth through the RF terrestrial link and also transmits an optical beacon to the satellite for spacecraft return pointing and for the alignment of the transmitting optics. Future work will turn to modulation and coding, pointing and tracking, and optical-RF interfacing.

Dolinar, S.; Vilnrotter, V.; Gagliardi, R.

1981-01-01

238

Handbook on satellite communications and broadcasting  

NASA Astrophysics Data System (ADS)

Principles underlying the design and operation of satellite communications systems (SCSs) are reviewed with emphasis on multiple-access techniques. Particular consideration is given to the quality characteristics of CSCs, the frequency ranges assigned to SCSs, an energy analysis of satellite lines, EMC aspects, and the effective utilization of the geostationary orbit. Also examined are the design of earth-station equipment, waveguides and multiplexing equipment, satellite antennas, reliability issues, the Ekran receiving installation, and Gradient-N and Gruppa multiple-access equipment.

Askinazi, G. B.; Bykov, V. L.; Vodopianov, G. V.; D'Iachkova, M. N.; Kantor, L. Ia.; Model, A. M.; Pokras, A. M.; Timofeev, V. V.; Tsirlin, V. M.; Tsirlin, I. S.

239

The 30/20 GHz fixed communications systems service demand assessment. Volume 3: Appendices  

NASA Technical Reports Server (NTRS)

The market analysis of voice, video, and data 18/30 GHz communications systems services and satellite transmission services is discussed. Detail calculations, computer displays of traffic, survey questionnaires, and detailed service forecasts are presented.

Gabriszeski, T.; Reiner, P.; Rogers, J.; Terbo, W.

1979-01-01

240

The 30/20 GHz Fixed Communications Systems Service Demand Assessment. Volume 3: Appendices.  

National Technical Information Service (NTIS)

The market analysis of voice, video, and data 18/30 GHz communications systems services and satellite transmission services is discussed. Detail calculations, computer displays of traffic, survey questionnaires, and detailed service forecasts are presente...

T. Gabriszeski P. Reiner J. Rogers W. Terbo

1979-01-01

241

GLOBAL MOBILE SATELLITE COMMUNICATIONS: A REVIEW OF THREE CONTENDERS  

Microsoft Academic Search

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

Gary M. Comparetto

1994-01-01

242

Active antennas for satellite communications  

NASA Astrophysics Data System (ADS)

The feasibility of replacing the high-power traveling-wave tube amplifiers (TWTA's) of a satellite antenna transmit system by many low-power solid-state power amplifiers (SSPA's) each driving a feed radiating element is examined in this paper. In view of the requirement of a one watt output power from each such low-power SSPA, the design, fabrication, and performance of a 1-watt SSPA are also described in this paper. In addition, the suitability of a number of antenna configurations as active antennas has been evaluated for C-Band shaped beam Intelsat applications.

Parekh, S. V.; Soule, H. H.; Cummings, M.; Bornemann, W.

243

Overview of TCTS satellite service applications  

NASA Astrophysics Data System (ADS)

An overview is presented of existing satellite service applications of the TransCanada Telephone System (TCTS) and its member companies, and future plans considered of significant interest to the business community are highlighted. TCTS currently manages two major long-haul message trunking networks over satellite to augment to capacity of existing terrestrial facilities and to provide route diversity. The history and operation of these message trunking applications are described. Video service applications of TCTS are briefly considered, including educational and pay-TV services and the CBC network. Business and special service applications include transportable earth station service and customer high-speed data services. Future service applications are addressed.

Savas, M. J.

244

An Orbiting Standards Platform for communication satellite system RF measurements  

NASA Technical Reports Server (NTRS)

The Orbiting Standards Platform (OSP) is a proposed satellite dedicated to performing RF measurements on space communications systems. It would consist of a quasi-geostationary spacecraft containing an ensemble of calibrated RF sources and field strength meters operating in several microwave bands, and would be capable of accurately and conveniently measuring critical earth station and satellite RF performance parameters, such as EIRP, gain, figure of merit (G/T), crosspolarization, beamwidth, and sidelobe levels. The feasibility and utility of the OSP concept has been under joint study by NASA, NBS, Comsat and NTIA. A survey of potential OSP users was conducted by NTIA as part of this effort. The response to this survey, along with certain trends in satellite communications system design, indicates a growing need for such a measurement service.

Wallace, R. G.; Woodruff, J. J.

1978-01-01

245

Human Interfaces for Robotic Satellite Servicing.  

National Technical Information Service (NTIS)

On-orbit servicing (OOS) is growing in importance for the sustainment of certain satellite systems. Although it is more economical to replace satellites in many cases, OOS could be beneficial or even critical for more expensive satellites such as Space-Ba...

J. D. Ianni D. Repperger R. W. Baker R. L. Williams

1999-01-01

246

Method for scrambling satellite communications  

NASA Technical Reports Server (NTRS)

A secure communications system multiplexes segments of the information signal for keyed encoding and modulation onto a plurality of different carrier frequencies and/or polarizations, and transmits the encoded carriers to multi-channel signal summing receivers that decode the segments from all channels, to reassemble the information signal for use by authorized stations with a key. The use of the multi-channel link and the summing receiver allows the greatest number of different coding algorithms for accommodating the greatest number of discrete secure channels.

Brockman, Milton H. (Inventor)

1992-01-01

247

Multiple beam antennas for communication satellites  

Microsoft Academic Search

Multihorn array feeds in an offset reflector or lens can be used to radiate multiple zone coverage beams from a single aperture. A new technique is described for synthesizing shaped cross-section zone coverage beams with extremely low sidelobes. This development has important application for communication satellites that require multiple zonal beams with large amplitude isolation between beams to permit frequency

J. W. Duncan

1975-01-01

248

Viterbi Decoding for Satellite and Space Communication  

Microsoft Academic Search

Convolutional coding and Viterbi decoding, along with binary phase-shift keyed modulation, is presented as an efficient system for reliable communication on power limited satellite and space channels. Performance results, obtained theoretically and through computer simulation, are given for optimum short constraint length codes for a range of code constraint lengths and code rates. System efficiency is compared for hard receiver

J. Heller; I. Jacobs

1971-01-01

249

Distributed Source Coding for Satellite Communications  

Microsoft Academic Search

Inspired by mobile satellite communications systems, we consider a source coding system which consists of multiple sources, multiple encoders, and multiple decoders. Each encoder has access to a certain subset of the sources, each decoder has access to certain subset of the encoders, and each decoder reconstructs a certain subset of the sources almost perfectly. The connectivity between the sources

Raymond W. Yeung; Zhen Zhang

1999-01-01

250

Delta capability for launch of communications satellites  

Microsoft Academic Search

The evolution of capabilities and the current performance levels of the Delta launch vehicle are outlined. The first payload was the Echo I passive communications satellite, weighing 179 lb, and placed in GEO in 1960. Emphasis since then has been to use off-the-shelf hardware where feasible. The latest version in the 3924 first stage, 3920 second stage, and Pam D

D. W. Grimes; W. A. Russell Jr.; J. D. Kraft

1982-01-01

251

Phased array for mobile satellite communications  

NASA Astrophysics Data System (ADS)

An L-band phased array antenna concept for mobile satellite communications is presented. The array is a multilayer structure with integrated 4-bit switched stub phase shifters and aperture coupled right hand circularly polarized antenna elements. The integrated phased array has an interface for direct computer control. Diagrams describing the operation and structure of the antenna are shown.

Ziegler, Volker

1990-11-01

252

MIC linearizer for satellite communications  

NASA Astrophysics Data System (ADS)

MIC implementation of a predistortion-type nonlinearity compensating circuit or linearizer (LRZ) using FETAs in a distortion generator was studied and a compact, lightweight MIC-LRZ using tip devices was developed. The LRZ circuit has a symmetric construction which enables it to have a wideband characteristic, and its nonlinearities can be adjusted electrically. The LRZ can compensate nonlinearity up to saturation of the traveling wave tube amplifier (TWTA) and can provide large performance improvement using a TWTA with backoff operation. The TWTA with the soft-limiter LRZ (SL-LRZ) exhibits soft-limiter transfer characteristics in which the input-output amplitude response is linear up to saturation and phase nonlinearity is negligible. The MIC-LRZ and SL-LRZ are compact, lightweight, and effective for use with earth stations HPAs and satellite TWTAs.

Sato, G.

1985-05-01

253

Converged Media and Communication Services  

Microsoft Academic Search

Converged media and communication services (COMCO) is the conceptual approach of integrating telecommunication, Web 2.0 and Media\\/IPTV in one architectural approach. Current available service delivery platform (SDP) concepts are silo approaches, which belong more or less to one of the three groups: (mobile\\/fix) telecommunication SDP, IPTV SDP and pure Web SDP. The groups have in common the integration of OSS\\/BSS

Jens Fiedler; Christian Riede; Thomas Magedanz

2008-01-01

254

Mobile satellite communications - Vehicle antenna technology update  

NASA Astrophysics Data System (ADS)

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.

Bell, D.; Naderi, F. M.

255

Communications technology satellite - United States experiments and disaster communications applications  

NASA Technical Reports Server (NTRS)

The experimental Communications Technology Satellite (CTS), also called Hermes, uses a high-power transmitter and 12- and 14-GHz frequencies for wideband (two- and one-way television) and narrowband (voice, data) communications. In the joint program, both Canada and the United States have conducted a variety of communications experiments. This report concentrates on U.S. CTS experiments and miniexperiments that use ground antennas from 0.6 to 5 meters in diameter. The U.S. CTS experiments program is synopsized in this report. The use of CTS for simulated and actual disasters is summarized.

Donoughe, P. L.; Hunczak, H. R.; Gurski, G. S.

1978-01-01

256

Performance of Duplex Communication between a Leo Satellite and Terrestrial Location Using a Geo Constellation  

NASA Technical Reports Server (NTRS)

A network comprised of a terrestrial site, a constellation of three GEO satellites and a LEO satellite is modeled and simulated. Continuous communication between the terrestrial site and the LEO satellite is facilitated by the GEO satellites. The LEO satellite has the orbital characteristics of the International Space Station. Communication in the network is based on TCP/IP over ATM, with the ABR service category providing the QoS, at OC-3 data rate. The OSPF protocol is used for routing. We simulate FTP file transfers, with the terrestrial site serving as the client and the LEO satellite being the server. The performance characteristics are presented.

Robinson, Daryl C.; Konangi, Vijay K.; Wallett, Thomas M.

1998-01-01

257

Cable Communications and Social Services.  

ERIC Educational Resources Information Center

Some of the ways in which cable communications may affect society's ability to help individuals who, in one way or another, are less fortunate than most are explored. The services contemplated here include job training and placement, family counseling, rehabilitation, and home management assistance. The proposed audience would include those who…

Alfred P. Sloan Foundation, New York, NY.

258

Low and medium Earth orbit satellite systems: spheres application, services and customers  

Microsoft Academic Search

As the direction of developments in mobile communication networks has been changing, the efforts of operators of ground and satellite systems of mobile communication has been uniting. Thus the scope of services in this sphere has been increasing continuously. This fact has given us ground to suppose that the market for mobile communication services in Russia, as it was estimated

A. B. Antonyan; N. V. Volchkova

1998-01-01

259

Indoor RF Unit for Satellite Communication and Phase Noise Characteristics.  

National Technical Information Service (NTIS)

An indoor RF unit for satellite communications has been developed. In satellite communications, especially low phase noise characteristics of the local oscillator are required to attain a low bit error rate. Theoretical formulas have been derived through ...

K. Yamakawa S. Aoki I. Koyama M. Tsuneoka T. Sato

1989-01-01

260

Pegasus dedicated and multiple launch capabilities for low earth orbit communications satellite constellations  

NASA Astrophysics Data System (ADS)

The design and standard payload interfaces of the Pegasus air-launched space booster are described and an overview of integration and launch operations is presented. Specific attention is given to services which are available to support multiple satellite launches. A recent multiple launch of seven small communication satellites is described which demonstrates Pegasus' capabilities to populate LEO communications satellite constellations quickly and cost effectively.

Mosier, Marty

1992-03-01

261

The future for communication satellites of the PAM-D\\/half Ariane class  

Microsoft Academic Search

The underpinnings of the current orders for 50 communications satellites, to be manufactured by four companies, are examined, with attention given to future progress in communications satellites. Existing launch services include the Delta 3920 (PAM-D kick stage, 1247 kg), the Shuttle and a PAM-D (1247 kg), and the Ariane 3\\/Sylda (two 1195 kg packages). Half the satellite mass will be

U. Renner

1983-01-01

262

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

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

263

A generalized transmultiplexer and its application to mobile satellite communications  

NASA Technical Reports Server (NTRS)

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

Ichiyoshi, Osamu

1990-01-01

264

Satellite systems requirements for land mobile communications  

NASA Technical Reports Server (NTRS)

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.

Horstein, M.

1983-01-01

265

Analysis of optical coherence multiplexing networks for satellite communication  

Microsoft Academic Search

Free-space optical communication between satellites networked together can enable a high data rate between the satellites. Coherence multiplexing (CM) is an attractive tech- nique for satellite networking due to its ability to cope with the asynchronous nature of communication traffic and the dynamic changes taking place in the satellite constellation. The use of optical radiation for intersatellite links creates very

G. Kats; Schlomi Arnon

2004-01-01

266

Computer control of a robotic satellite servicer  

NASA Technical Reports Server (NTRS)

The advantages that will accrue from the in-orbit servicing of satellites are listed. It is noted that in a concept in satellite servicing which holds promise as a compromise between the high flexibility and adaptability of manned vehicles and the lower cost of an unmanned vehicle involves an unmanned servicer carrying a remotely supervised robotic manipulator arm. Because of deficiencies in sensor technology, robot servicing would require that satellites be designed according to a modular concept. A description is given of the servicer simulation hardware, the computer and interface hardware, and the software. It is noted that several areas require further development; these include automated docking, modularization of satellite design, reliable connector and latching mechanisms, development of manipulators for space environments, and development of automated diagnostic techniques.

Fernandez, K. R.

1980-01-01

267

Optical intersatellite links - Application to commercial satellite communications  

NASA Technical Reports Server (NTRS)

Application of optical intersatellite links for commercial satellite communications services is addressed in this paper. The feasibility of commercialization centers around basic issues such as the need and derived benefits, implementation complexity and overall cost. In this paper, commercialization of optical ISLs is assessed in terms of the services provided, systems requirements and feasibility of appropriate technology. Both long- and short-range ISLs for GEO-GEO, GEO-LEO and LEO applications are considered. Impact of systems requirements on the payload design and use of advanced technology in reducing its mass, power, and volume requirements are discussed.

Paul, D.; Faris, F.; Garlow, R.; Inukai, T.; Pontano, B.; Razdan, R.; Ganz, Aura; Caudill, L.

1992-01-01

268

15 CFR 950.8 - Satellite Data Services Division (SDSD).  

Code of Federal Regulations, 2010 CFR

...2014-01-01 2014-01-01 false Satellite Data Services Division (SDSD). 950...ENVIRONMENTAL DATA AND INFORMATION § 950.8 Satellite Data Services Division (SDSD). The Satellite Data Services Division of the EDIS...

2014-01-01

269

Prospects of satellite communication and broadcasting systems in the USSR based on modern launch technology  

NASA Astrophysics Data System (ADS)

A review is presented of the status of satellite communication and broadcasting in the USSR, its capabilities and possible trends of future development. Attention is given to the main communication and television broadcasting satellites, the distribution of sound broadcasting programs, satellite telephony systems, and newspaper facsimile transmission systems. Consideration is given to the parameters of launchers putting satellites into geostationary orbit, the possibilities for reducing sizes and costs of earth stations in the public switched and broadcasting services, private business communication networks, and television news relaying by means of transportable stations.

Kantor, Lev Ia.

1991-01-01

270

Reconsidering Social Networks for Enterprise Communication Services  

Microsoft Academic Search

Social networking applications leverage valuable information from social graphs and integrate communication capabilities to offer new services. However, currently, these applications are limited to communication capabilities such as click-to-call or click-to-conference. Once the communication session is established the social context and the communication context are not integrated in these services. For social network communication services such integration permits new and

Krishna Kishore Dhara; Venkatesh Krishnaswamy; Taranjeet Singh

2010-01-01

271

Voice intelligibility in satellite mobile communications  

NASA Technical Reports Server (NTRS)

An amplitude control technique is reported that equalizes low level phonemes in a satellite narrow band FM voice communication system over channels having low carrier to noise ratios. This method presents at the transmitter equal amplitude phonemes so that the low level phonemes, when they are transmitted over the noisey channel, are above the noise and contribute to output intelligibility. The amplitude control technique provides also for squelching of noise when speech is not being transmitted.

Wishna, S.

1973-01-01

272

Intersatellite link application to commercial communications satellites  

NASA Technical Reports Server (NTRS)

The fundamental characteristics of intersatellite link (ISL) systems, and their application to domestic, regional, and global satellite communications, are described. The quantitative advantages of using ISLs to improve orbit utilization, spectrum occupancy, transmission delay (compared to multi-hop links), coverage, and connectivity, and to reduce the number of earth station antennas, are also presented. Cost-effectiveness and other systems benefits of using ISLs are identified, and the technical and systems planning aspects of ISL systems implementation are addressed.

Lee, Young S.; Atia, Ali E.; Ponchak, Denise S.

1988-01-01

273

Wireless Communication in LEO Satellite Formations  

Microsoft Academic Search

In this paper we investigate key IEEE 802.11 optimization techniques with the aim to adapt the commercial-of-the-shelf (COTS) wireless standard for inter-satellite communication in autonomous distributed spacecraft formations. Optimisation approaches such as the tuning of the IEEE 802.11 physical layer parameters and enhancing the data link layer for space applications are described. The integration of smart antennas with the MAC

Kawsu Sidibeh; Tanya Vladimirova

2008-01-01

274

United States societal experiments via the Communications Technology Satellite  

NASA Technical Reports Server (NTRS)

After a brief description of the Communication Technology Satellite and its U.S. coverage, the U.S. societal experiments via the CTS are discussed. These include education (college curriculum sharing, and project interchange), health care (biomedical communications, health communications, and communication support for decentralized education), and community and special experiments (satellite library information network, and transportable earth terminal).

Donoughe, P. L.

1976-01-01

275

Feasibility of NASA TT&C via Commercial Satellite Services  

NASA Technical Reports Server (NTRS)

This report presents the results of a study to identify impact and driving requirements by implementing commercial satellite communications service into traditional National Aeronautics and Space Administration (NASA) space-ground communications. The NASA communication system is used to relay spacecraft and instrument commands, telemetry and science data. NASA's goal is to lower the cost of operation and increase the flexibility of spacecraft operations. Use of a commercial network offers the opportunity to contact a spacecraft on a nearly "on-demand" basis with ordinary phone calls to enable real time interaction with science events.

Mitchell, Carl W.; Weiss, Roland

1997-01-01

276

FEC decoder design optimization for mobile satellite communications  

NASA Technical Reports Server (NTRS)

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

Roy, Ashim; Lewi, Leng

1990-01-01

277

Satellite switched FDMA advanced communication technology satellite program  

NASA Technical Reports Server (NTRS)

The satellite switched frequency division multiple access system provided a detailed system architecture that supports a point to point communication system for long haul voice, video and data traffic between small Earth terminals at Ka band frequencies at 30/20 GHz. A detailed system design is presented for the space segment, small terminal/trunking segment at network control segment for domestic traffic model A or B, each totaling 3.8 Gb/s of small terminal traffic and 6.2 Gb/s trunk traffic. The small terminal traffic (3.8 Gb/s) is emphasized, for the satellite router portion of the system design, which is a composite of thousands of Earth stations with digital traffic ranging from a single 32 Kb/s CVSD voice channel to thousands of channels containing voice, video and data with a data rate as high as 33 Mb/s. The system design concept presented, effectively optimizes a unique frequency and channelization plan for both traffic models A and B with minimum reorganization of the satellite payload transponder subsystem hardware design. The unique zoning concept allows multiple beam antennas while maximizing multiple carrier frequency reuse. Detailed hardware design estimates for an FDMA router (part of the satellite transponder subsystem) indicate a weight and dc power budget of 353 lbs, 195 watts for traffic model A and 498 lbs, 244 watts for traffic model B.

Atwood, S.; Higton, G. H.; Wood, K.; Kline, A.; Furiga, A.; Rausch, M.; Jan, Y.

1982-01-01

278

Engineering calculations for communications satellite systems planning  

NASA Technical Reports Server (NTRS)

Progress is reported on a computer code to improve the efficiency of spectrum and orbit utilization for the Broadcasting Satellite Service in the 12 GHz band for Region 2. It implements a constrained gradient search procedure using an exponential objective function based on aggregate signal to noise ratio and an extended line search in the gradient direction. The procedure is tested against a manually generated initial scenario and appears to work satisfactorily. In this test it was assumed that alternate channels use orthogonal polarizations at any one satellite location.

Martin, C. H.; Gonsalvez, D. J.; Levis, C. A.; Wang, C. W.

1983-01-01

279

Future Satellite Navigation Services and Augmentations.  

National Technical Information Service (NTIS)

This report is intended to provide a high-level view of the evolving changes in satellite navigation services. Satellite navigation dates back as one of the first space applications. The report provides a chronological review of the development of the Glo...

J. W. Spalding

2006-01-01

280

Traffic model for advanced satellite designs and experiments for ISDN services  

NASA Technical Reports Server (NTRS)

The data base structure and fields for categorizing and storing Integrated Services Digital Network (ISDN) user characteristics is outlined. This traffic model data base will be used to exercise models of the ISDN Advanced Communication Satellite to determine design parameters and performance for the NASA Satellite Communications Applications Research (SCAR) Program.

Pepin, Gerard R.; Hager, E. Paul

1991-01-01

281

47 CFR 25.149 - Application requirements for ancillary terrestrial components in the Mobile-Satellite Service...  

Code of Federal Regulations, 2013 CFR

...terrestrial components in the Mobile-Satellite Service networks operating in the 1...1.6/2.4 GHz and 2 GHz Mobile-Satellite Service. 25.149 Section 25.149...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and...

2013-10-01

282

47 CFR 25.149 - Application requirements for ancillary terrestrial components in the mobile-satellite service...  

Code of Federal Regulations, 2010 CFR

...terrestrial components in the mobile-satellite service networks operating in the 1...1.6/2.4 GHz and 2 GHz mobile-satellite service. 25.149 Section 25.149...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and...

2010-10-01

283

47 CFR 25.149 - Application requirements for ancillary terrestrial components in the mobile-satellite service...  

Code of Federal Regulations, 2010 CFR

...terrestrial components in the mobile-satellite service networks operating in the 1...1.6/2.4 GHz and 2 GHz mobile-satellite service. 25.149 Section 25.149...CONTINUED) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Applications and...

2009-10-01

284

Communication over IP Based on Web Services  

Microsoft Academic Search

In this paper, we study the communication over IP based on web services. We describe the service-oriented communication framework of WIP, Web Services Initiation Protocol, and focus on its web centric networking infrastructure. In our approach, WIP endpoints are exposed as resources on the Web, publishable by their UDDI service registries. They can be searched and discovered by regular web

Wu Chou; Li Li

2008-01-01

285

A digitally implemented communications experiment utilizing the communications technology satellite, Hermes  

NASA Technical Reports Server (NTRS)

Developments which will reduce the costs associated with the distribution of satellite services are considered with emphasis on digital communication link implementation. A digitally implemented communications experiment (DICE) which demonstrates the flexibility and efficiency of digital transmission of television video and audio, telephone voice, and high-bit-rate data is described. The utilization of the DICE system in a full duplex teleconferencing mode is addressed. Demonstration teleconferencing results obtained during the conduct of two sessions of the 7th AIAA Communication Satellite Systems Conference are discussed. Finally, the results of link characterization tests conducted to determine (1) relationships between the Hermes channel 1 EIRP and DICE model performance and (2) channel spacing criteria for acceptable multichannel operation, are presented.

Jackson, H. D.; Fiala, J.

1980-01-01

286

An Earth orbiting satellite service and repair facility  

NASA Technical Reports Server (NTRS)

A conceptual design was produced for the Geosynchronous Satellite Servicing Platform (GSSP), an orbital facility capable of repairing and servicing satellites in geosynchronous orbit. The GSSP is a man-tended platform, which consists of a habitation module, operations module, service bay and truss assembly. This design review includes an analysis of life support systems, thermal and power requirements, robotic and automated systems, control methods and navigation, and communications systems. The GSSP will utilize existing technology available at the time of construction, focusing mainly on modifying and integrating existing systems. The entire facility, along with two satellite retrieval vehicles (SRV), will be placed in geosynchronous orbit by the Advanced Launch System. The SRV will be used to ferry satellites to and from the GSSP. Technicians will be transferred from Earth to the GSSP and back in an Apollo-derived Crew Transfer Capsule (CTC). These missions will use advanced telerobotic equipment to inspect and service satellites. Four of these missions are tentatively scheduled per year. At this rate, the GSSP will service over 650 satelites during the projected 25 year lifespan.

Berndt, Andrew; Cardoza, Mike; Chen, John; Daley, Gunter; Frizzell, Andy; Linton, Richard; Rast, Wayne

1989-01-01

287

The communication-satellite market to the year 2000  

NASA Astrophysics Data System (ADS)

The developmental history of communication satellites (CSs) is traced; the demands placed on industry by the increasing sophistication of CS payloads, the need to adapt the CS to different launchers (STS or Ariane), and the requirement of longer service life are reviewed; and the evolution of the markets for fixed (telephone, telex, and facsimile), video, business, and broadcasting service is projected over the period 1980-2000 and illustrated with tables and graphs. It is predicted that the worldwide market, expressed in terms of the demand for 36-Mhz transponders, will increase from 426 in 1980 to 1410 in 1985, 3100 in 1990, 5580 in 1995, and 9870 in 2000, with the main increase in transponders for voice communications. The potential for Netherlands participation in the growth of the CS market is evaluated, and the need for government leadership and for active promotion efforts is stressed.

van Duinen, R. J.

1984-10-01

288

Discussion on the progress and future of satellite communication (Japan)  

NASA Technical Reports Server (NTRS)

The current status of communications satellite development in Japan is presented. It is shown that beginning with research on satellite communucations in the late 1950's, progress was made in the areas of communications, remote sensing, and technology experimentation. The current status of communication satellites is presented, stressing development in the areas of CFRP construction elements, the use of LSI and MIC circuits, advanced multibeam antenna systems, Ku and Ka band transmission systems, and the shift to small-scale earth stations. Methods for reducing costs and increasing transmission efficiency are shown. The technical specifications of all satellite projects currently under development are given. Users of Japanese communications satellite are presented.

Ogata, M.; Mizusawa, H.; Irie, K.

1985-01-01

289

Mobile communications via satellite in the 1990s  

NASA Astrophysics Data System (ADS)

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

Lundberg, O.

1984-07-01

290

High accuracy deployable antenna for communications satellite  

NASA Astrophysics Data System (ADS)

High frequency multi-beam satellite antennas have been studied to realize increased communication capacity, simplified earth stations, and multiple frequency reuse. The satellite antenna needs a highly accurate and large reflector. To overcome the launching vehicle's constraints in size and weight, a solid deployable antenna is under development. A petal antenna (PETAL), composed of solid shell elements, has been studied as a high frequency use deployable antenna. It is an axi-symmetric antenna composed of a fixed central shell and deployable triangular and square shells. During the launch phase, a restraining cable is bound around the periphery of deployable elements stowed in a hexagonal configuration. Deployment is initiated by pyrotechnic cable cutters, and the shells are deployed by spring action.

Watanabe, M.; Misawa, M.; Minomo, M.; Yasaka, T.

291

Project Universe - Local area networks and satellite communications  

Microsoft Academic Search

A high-speed digital communications system is discussed in which a satellite is used to link a number of local area networks which interconnect a variety of computer facilities. The advantages of satellite communications compared with terrestrial links are described, together with a historical survey of the use of the Orbital Test Satellite (OTS) for data experiments. A description of Project

B. R. Ackroyd

1983-01-01

292

A New Era Begins: Satellite Communications and Development.  

ERIC Educational Resources Information Center

This overview of changes in the field of telecommunications development produced by satellite communications over the last 15 years focuses on applications of satellite systems for educational and health purposes in developing countries. Satellite communications development from 1974 to 1986 is identified as the first stage of telecommunications…

Pelton, Joseph N.

293

NATO III satellite communications system control  

NASA Astrophysics Data System (ADS)

The System Control concepts to improve channel utilization and the recent progress of the design, development and integration of the Control Subsystem for the NATO III network are reported. The network operates with a large number of single destination TDM/QPSK/FDMA carriers to provide voice, low speed telegraph and medium speed data circuits. A power control algorithm to keep the link quality at the desired nominal level as well as improve satellite capacity and a traffic control algorithm allowing reconfiguration of the network to accommodate fluctuating traffic are presented. The System Control Software development cycle, consisting of top level design, which includes functional decomposition and software module structure, detailed design, integration and testing phases, is discussed. Various functional flow diagrams are provided illustrating the information interfaces to external communications, inter-component communications, the network database and the physical devices. An example illustrating the performance of power control and traffic control software is presented.

Sanli, N.; Lo, S. C.; Kota, S. L.; Aronson, M. H.

1984-04-01

294

The NATO III satellite communications system control  

NASA Astrophysics Data System (ADS)

The System Control concepts to improve channel utilization and the recent progress of the design, development and integration of the Control Subsystem for the NATO III network are reported. The network operates with a large number of single destination TDM/QPSK/FDMA carriers to provide voice, low speed telegraph and medium speed data circuits. A power control algorithm to keep the link quality at the desired nominal level as well as improve satellite capacity and a traffic control algorithm allowing reconfiguration of the network to accommodate fluctuating traffic are presented. The System Control Software development cycle, consisting of top level design, which includes functional decomposition and software module structure, detailed design, integration and testing phases, is discussed. Various functional flow diagrams are provided illustrating the information interfaces to external communications, inter-component communications, the network database and the physical devices. An example illustrating the performance of power control and traffic control software is presented.

Sanli, N.; Lo, S. C.; Kota, S. L.; Aronson, M. H.

295

Satellite and terrestrial integrated services digital networks in Japan  

NASA Astrophysics Data System (ADS)

Satellite and terrestrial Integrated Services Digital Networks (ISDN) to provide cost effective ISDN services and to enhance installation of ISDN services all over the nation are proposed. The proposed networks are based on the traffic sharing between satellite and terrestrial networks for traffic transmission among telephone offices and provide satellite subscriber lines for ISDN customers in rural areas. The former DYANET (dynamic channel assigning routing satellite aided digital networks) (1) takes the advantage of high transmission efficiency of terrestrial networks for steady traffic and the advantage of high transmission efficiency of satellite communications for light and dynamically varying traffic. By employing demand assignment and transponder hopping (for both transmission and reception) techniques, effective satellite transmission capacity is encreased to five to six times higher than that of preassignment systems. Moreover, earth station cost was significantly reduced by Large Scale Integrated Circuits (LSIC) and Monolithic Integrated Circuit (MIC) implementation and by the development of dual beam antennas. DYANET 1 has been in perfect operation employing 64 Time Division Multiple Access (TDMA) earth stations since 1988 and the latter (DYANET 2) will be put into commercial use from mid 1991.

Yamamoto, Heiichi; Kato, Shuzo

1991-10-01

296

The Future of Satellite Communications. Resource Management and the Needs of Nations.  

ERIC Educational Resources Information Center

Recent events suggest that Intelsat (the 68-nation International Telecommunications Satellite Consortium) will coordinate a number of domestic and regional systems that provide satellite communications services, some of which will be maintained by Intelsat and some of which will be independent. This report addresses the problems of conflict in…

Hinchman, Walter R.; Dunn, D. A.

297

Experimental mobile satellite system for communications using engineering test satellite-V(ETS-V/EMSS-C)  

NASA Astrophysics Data System (ADS)

For establishing key technology of the maritime satellite communication system for small vessels and the aeronautical satellite communications and for research on general mobile satellite communications, Experimental Mobile Satellite System for Communications using Engineering Test Satellite-V(ETS-V/EMSS-C) is developed in Japan. Phase C development of the satellite and transponders will start this year and development of an aircraft earth station and a coast/aeronautical earth station have started. Ship earth stations and small mobile stations will be developed in 1985. C-band and L-band frequencies are used for communications experiments. A multibeam antenna and solid state transponders are used on the satellite and digital communication technics play an important role. The satellite will be launched in 1987.

Miura, S.; Ishide, A.; Kondo, K.

1984-10-01

298

Communications technology satellite: United States experiments and disaster communications applications  

NASA Technical Reports Server (NTRS)

Ground antennas from 0.6 to 5.0 meters in diameter were used as remote earth terminals by the United States for both wideband (television) and narrowband (voice, data) communication in conjunction with the Canadian Hermes satellite's high power transmitter. Experiments summarized cover teleconferencing and duplex videoconferencing for medical, educational, and civic purposes, as well as the remote interpretation of multilingual broadcasts from the United Nations. The capabilities of the system during real and simulated disasters at airports are assessed. Particular attention is given to miniexperiments for flood control in the Mississippi River basin and in Johnstown, Pennsylvania during the 1977 flood.

Donoughe, P.; Hunczak, H. R.; Gurski, G. S.

1978-01-01

299

Personal communications services: Improving theater deployable communications for the 21st century  

NASA Astrophysics Data System (ADS)

Personal Communications Services (PCS) may be the key ingredient for vastly improved military communications capabilities at the turn of the century. The Federal Communications Commission (FCC) defines PCS as a family of mobile or portable radio communications services which could provide services to individuals and businesses and be integrated with a variety of competing networks ... the primary focus of PCS will be to meet communications requirements of people on the move. Today's generation of Theater Deployable Communications, which provides joint tactical communications to deployed forces, is the Tri-Service Tactical Communications (TRI-TAC) system. A description of TRITAC's family of equipment, network topology, typical employment, and critical limitations is presented in this thesis. Five commercial Mobile Satellite Services (MSS) are described as viable candidates for augmenting existing communications systems. Cellular design principles such as frequency reuse, cell splitting, channel access methods, and propagation factors are also addressed. Finally, a framework for comparison of the candidate MSS systems is proposed as a baseline for further studies into the most beneficial implementation of PCS into theater deployable communications systems for the future.

Cournoyer, Ronald C., Jr.

1994-06-01

300

ESA personal communications and digital audio broadcasting systems based on non-geostationary satellites  

NASA Astrophysics Data System (ADS)

Personal Communications and Digital Audio Broadcasting are two new services that the European Space Agency (ESA) is investigating for future European and Global Mobile Satellite systems. ESA is active in promoting these services in their various mission options including non-geostationary and geostationary satellite systems. A Medium Altitude Global Satellite System (MAGSS) for global personal communications at L and S-band, and a Multiregional Highly inclined Elliptical Orbit (M-HEO) system for multiregional digital audio broadcasting at L-band are described. Both systems are being investigated by ESA in the context of future programs, such as Archimedes, which are intended to demonstrate the new services and to develop the technology for future non-geostationary mobile communication and broadcasting satellites.

Logalbo, P.; Benedicto, J.; Viola, R.

301

ESA personal communications and digital audio broadcasting systems based on non-geostationary satellites  

NASA Technical Reports Server (NTRS)

Personal Communications and Digital Audio Broadcasting are two new services that the European Space Agency (ESA) is investigating for future European and Global Mobile Satellite systems. ESA is active in promoting these services in their various mission options including non-geostationary and geostationary satellite systems. A Medium Altitude Global Satellite System (MAGSS) for global personal communications at L and S-band, and a Multiregional Highly inclined Elliptical Orbit (M-HEO) system for multiregional digital audio broadcasting at L-band are described. Both systems are being investigated by ESA in the context of future programs, such as Archimedes, which are intended to demonstrate the new services and to develop the technology for future non-geostationary mobile communication and broadcasting satellites.

Logalbo, P.; Benedicto, J.; Viola, R.

1993-01-01

302

Satellite switching concepts for European business services in the nineties  

NASA Astrophysics Data System (ADS)

A first generation of business communication satellites are now operational or to be launched. Increased demands for communication satellite facilities will develop, if special services, such as videoconferencing, can be provided at a reasonable cost. For such developments, it will be necessary to define a second generation of business communication satellites. The present investigation evaluates briefly the size of the expected European market for 1995. A study is conducted of the payload structure for the required satellite system, and aspects related to link budgets and power consumption are explored. It is found that system dimensioning is determined by the up-link and by technology. Critical factors are related to the output and input multiplexors for the link budget, the switching matrix, and implications for the mass budget. The best trade-off between technological, mass, and link budget limitations is achieved in connection with the employment of a hinged antennas satellite, using an intermediate number of spot beams and associated earth stations of reasonable size.

Lombard, D.; Rouffet, D.

303

The 18/30 GHz Fixed Communications System Service Demand Assessment. Volume 2: Main Text.  

National Technical Information Service (NTIS)

The total demand for communications services, and satellite transmission services at the 4/6 GHz, 12/14 GHz, and 18/30 GHz frequencies is assessed. The services are voice, video, and data services. Traffic demand, by service, is distributed by geographica...

T. Gabriszeski P. Reiner J. Rogers W. Terbo

1979-01-01

304

A study and experiment plan for digital mobile communication via satellite  

Microsoft Academic Search

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

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

1978-01-01

305

The northern Utah satellite (NUSAT) communications link  

NASA Technical Reports Server (NTRS)

During the planning stages of the NUSAT satellite, an obvious issue to be discussed was the method of communications to be used. The frequencies would have to be high enough to pass through the atmosphere relatively unattenuated but low enough that antennas and transmission lines would not be so critical in length and properties that unexperienced students would have difficulty with handling them. The frequencies of 450.000 MHz and 137.900 MHz were decided upon and applied for licensing. Representatives of the amateur radio satellite organization, AMSAT, were contacted for ideas. This organization seems to favor AM types of emissions such as CW to control their OSCAR series of satellites and also the current Phase 3 unit. NUSAT personnel felt, however, that there would be merit in the improved signal to noise ratio usually obtained in an FM mode. Doppler shift of the transmitted information on the NUSAT also had to be considered. The final decision was to use Audio Frequency Shift Keying (ASKF) modulated on an FM carrier. In this mode audio tones used would not shift frequency with Doppler.

Barrett, L.

1986-01-01

306

A Micro Satellite Communication System Architecture  

NASA Astrophysics Data System (ADS)

In 2000 the European Space Agency's (ESA) Office for Educational Project Outreach Activities has started the Student Space Exploration &Technology Initiative (SSETI). The main objective of this project is to construct and to launch a microsatellite developed by a network of European students. The microsatellite will be mainly used to transmit pictures of the space to earth, to perform plasma experiments and to test all the subsystems for further missions. The data transfer from on-board the satellite to the ground station will be ensued through an innovative communication system composed of two different channels alternatively used to built a connection with the earth. A low data rate channel has to be activated to download telemetry and upload telecommand during the stabilisation mode or when the satellite is not visible from the earth. During the microsatellite nominal operation mode, pictures and data of scientific interest have to be sent from space to the ground station through an additional high data rate channel. As the satellite operation mode changes, a switching system optimizes the onboard power budget selecting the most convenient option between a directive and an omnidirectional antenna, designed to implement the high and low data rate channels respectively. The low gain channel uses two circular polarised patches while a 2x2 microstrip array has been chosen for realising the high rate communication link. Both the antennas are low profile radiators and they have been designed to be conformally mounted onto the microsatellite surface. Prototypes of the two antennas have been realised and tested. A description of the antenna's design process will be given together with a review of the entire system architecture rationale.

Fragale, Francesco; Boccia, Luigi

2002-01-01

307

NASA to launch second business communications satellite  

NASA Astrophysics Data System (ADS)

The two stage Delta 3910 launch vehicle was chosen to place the second small business satellite (SBS-B) into a transfer orbit with an apogee of 36,619 kilometers and a perigee of 167 km, at an inclination of 27.7 degrees to Earth's equator. The firing and separation sequence and the inertial guidance system are described as well as the payload assist module. Facilities and services for tracking and control by NASA, COMSAT, Intelsat, and SBS are outlined and prelaunch operations are summarized.

1981-08-01

308

NASA to launch second business communications satellite  

NASA Technical Reports Server (NTRS)

The two stage Delta 3910 launch vehicle was chosen to place the second small business satellite (SBS-B) into a transfer orbit with an apogee of 36,619 kilometers and a perigee of 167 km, at an inclination of 27.7 degrees to Earth's equator. The firing and separation sequence and the inertial guidance system are described as well as the payload assist module. Facilities and services for tracking and control by NASA, COMSAT, Intelsat, and SBS are outlined and prelaunch operations are summarized.

1981-01-01

309

Engineering calculations for communications satellite systems planning  

NASA Technical Reports Server (NTRS)

Observed solution times were analyzed for the extended gradient and cyclic coordinate search procedures. The times used in the analysis come from computer runs made during a previously-reported experiment conducted to assess the quality of the solutions to a BSS synthesis problem found by the two search methods. The results of a second experiment with a Fixed Satellite Service (FSS) test problem are also presented. Computational results are summarized for mixed integer programming approaches for solving FSS synthesis problems. A promising heuristic algorithm is described. A synthesis model is discussed for orbital arc allotment optimization. Research plans for the near future are also presented.

Reilly, C. H.; Levis, C. A.; Buyukdura, O. M.; Mount-Campbell, C. A.

1986-01-01

310

On-board processing concepts for future satellite communications systems  

NASA Technical Reports Server (NTRS)

The initial definition of on-board processing for an advanced satellite communications system to service domestic markets in the 1990's is discussed. An exemplar system with both RF on-board switching and demodulation/remodulation baseband processing is used to identify important issues related to system implementation, cost, and technology development. Analyses of spectrum-efficient modulation, coding, and system control techniques are summarized. Implementations for an RF switch and baseband processor are described. Among the major conclusions listed is the need for high gain satellites capable of handling tens of simultaneous beams for the efficient reuse of the 2.5 GHz 30/20 frequency band. Several scanning beams are recommended in addition to the fixed beams. Low power solid state 20 GHz GaAs FET power amplifiers in the 5W range and a general purpose digital baseband processor with gigahertz logic speeds and megabits of memory are also recommended.

Brandon, W. T. (editor); White, B. E. (editor)

1980-01-01

311

A digital simulation of message traffic for natural disaster warning communications satellite  

NASA Technical Reports Server (NTRS)

Various types of weather communications are required to alert industries and the general public about the impending occurrence of tornados, hurricanes, snowstorms, floods, etc. A natural disaster warning satellite system has been proposed for meeting the communications requirements of the National Oceanic and Atmospheric Administration. Message traffic for a communications satellite was simulated with a digital computer in order to determine the number of communications channels to meet system requirements. Poisson inputs are used for arrivals and an exponential distribution is used for service.

Hein, G. F.; Stevenson, S. M.

1972-01-01

312

Optical Data Communication for Earth Observation Satellite Systems.  

National Technical Information Service (NTIS)

The current development status of optical communication engineering in comparison to the conventional microwave systems and the different configurations of the optical data communication for Earth observation satellite systems are described. An outlook to...

J. Fischer E. Loecherbach

1991-01-01

313

Customer Service Management: An Information Model for Communication Services  

Microsoft Academic Search

\\u000a Customer Service Management (CSM) offers a management interface between customer and service provider, which enables customers\\u000a to individually monitor and control their subscribed services. In order to model Customer Service Management for communication\\u000a services, this paper proposes a protocol and technology-independent information model, which incoporates the individual quality\\u000a of service parameters (QoS parameters) that are specified in customer-specific service level

Michael Langer; Michael Nerb

2000-01-01

314

Communications satellite systems operations with the space station. Volume 3: Supplementary technical report  

NASA Technical Reports Server (NTRS)

The NASA space station has the potential to provide significant economic benefits to commercial communications satellite operators. The initial reports qunatified the benefits of space-based activities and assessed the impacts on the satellite design and the space station. Results are given for the following additional tasks: quantify the value of satellite retrievability operations and define its operational aspects; evaluate the use of expendable launch vehicles for transportation of satellites from the Earth to the space station; and quantify the economic value of modular satellites that are assembled and serviced in space.

Price, K. M.; Russell, P.; Weyandt, C.

1988-01-01

315

Mass and power modeling of communication satellites  

NASA Technical Reports Server (NTRS)

Analytic estimating relationships for the mass and power requirements for major satellite subsystems are described. The model for each subsystem is keyed to the performance drivers and system requirements that influence their selection and use. Guidelines are also given for choosing among alternative technologies which accounts for other significant variables such as cost, risk, schedule, operations, heritage, and life requirements. These models are intended for application to first order systems analyses, where resources do not warrant detailed development of a communications system scenario. Given this ground rule, the models are simplified to 'smoothed' representation of reality. Therefore, the user is cautioned that cost, schedule, and risk may be significantly impacted where interpolations are sufficiently different from existing hardware as to warrant development of new devices.

Price, Kent M.; Pidgeon, David; Tsao, Alex

1991-01-01

316

Solid-state amplifiers for satellite communications  

NASA Astrophysics Data System (ADS)

At frequencies greater than 20 GHz, satellite communications transmitters require only moderate power outputs due to higher-gain antennas. Broadband helix TWT capabilities can be increased to 80 W at 44 GHz by using diamond helix supports; such a tube is being developed. IMPATT diodes are becoming the leading contenders for medium power amplification. Silicon, GaAs and InP devices are competing for use at EHF. A comparison between their respective properties is made and state-of-the-art performance is given. Single-diode and multidiode amplifier stages are described and some examples given. Since reliability is of primary importance for this application, some preliminary data supporting the MTTF predictions are presented.

Masse, D.; Harper, R.

317

SAW based systems for mobile communications satellites  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

318

Mass and power modeling of communication satellites  

NASA Astrophysics Data System (ADS)

Analytic estimating relationships for the mass and power requirements for major satellite subsystems are described. The model for each subsystem is keyed to the performance drivers and system requirements that influence their selection and use. Guidelines are also given for choosing among alternative technologies which accounts for other significant variables such as cost, risk, schedule, operations, heritage, and life requirements. These models are intended for application to first order systems analyses, where resources do not warrant detailed development of a communications system scenario. Given this ground rule, the models are simplified to 'smoothed' representation of reality. Therefore, the user is cautioned that cost, schedule, and risk may be significantly impacted where interpolations are sufficiently different from existing hardware as to warrant development of new devices.

Price, Kent M.; Pidgeon, David; Tsao, Alex

1991-12-01

319

Satellite Communications Technology Database. Part 2  

NASA Technical Reports Server (NTRS)

The Satellite Communications Technology Database is a compilation of data on state-of-the-art Ka-band technologies current as of January 2000. Most U.S. organizations have not published much of their Ka-band technology data, and so the great majority of this data is drawn largely from Japanese, European, and Canadian publications and Web sites. The data covers antennas, high power amplifiers, low noise amplifiers, MMIC devices, microwave/IF switch matrices, SAW devices, ASIC devices, power and data storage. The data herein is raw, and is often presented simply as the download of a table or figure from a site, showing specified technical characteristics, with no further explanation.

2001-01-01

320

Use of Satellite Natural Vibrations to Improve Performance of Free-Space Satellite Laser Communication  

NASA Astrophysics Data System (ADS)

In some of the future laser communication satellites, it is plausible to assume that tracking and communication receivers will use the same detector array. The reason for dual use of the detector is to design simpler and less expensive satellites. Satellites vibrate continually because of their subsystems and environmental sources. The vibrations cause nonuniform spreading of the received energy on the detector array. In view of this, the information from the tracking system is used to adapt individually the communication signal gain of each of the detectors in the array. This adaptation of the gains improves communication system performance. It is important to emphasize that the communication performance improvement is achieved only by gain adaptation. Any additional vibrations decrease the tracking and laser pointing system performances, which decrease the return communication performances (two-way communication). A comparison of practical communication systems is presented. The novelty of this research is the utilization of natural satellite vibrations to improve the communication system performance.

Arnon, Shlomi

1998-07-01

321

New television services on broadcasting satellites  

NASA Astrophysics Data System (ADS)

The 1983 Regional Administrative Radio Conference (RARC) has made major decisions on the usefulness of the 12 GHz band for direct broadcasting via satellites in Region 2 (North, Central, and South America). The planning conference adopted technical parameters such as satellite powers and bandwidth, and orbital separation between satellites which guarantees high performance of the channels to each administration in the Region. A Direct Broadcast Satellite (DBS) transmission format has been designed which takes account of present and future needs for video, audio, and data services. Attention has been given to the achievement of high quality in a low-cost receiver. A multiplexed analog component (MAC) format eliminates cross-color, cross-luminance, while four channels of high-quality audio are provided.

Bouchard, M.; Lucas, K.

322

A robust signalling system for land mobile satellite services  

NASA Technical Reports Server (NTRS)

Presented here is a signalling system optimized to ensure expedient call set-up for satellite telephony services in a land mobile environment. In a land mobile environment, the satellite to mobile link is subject to impairments from multipath and shadowing phenomena, which result in signal amplitude and phase variations. Multipath, caused by signal scattering and reflections, results in sufficient link margin to compensate for these variations. Direct signal attenuation caused by shadowing due to buildings and vegetation may result in attenuation values in excess of 10 dB and commonly up to 20 dB. It is not practical to provide a link with sufficient margin to enable communication when the signal is blocked. When a moving vehicle passes these obstacles, the link will experience rapid changes in signal strength due to shadowing. Using statistical models of attenuation as a function of distance travelled, a communication strategy has been defined for the land mobile environment.

Irish, Dale; Shmith, Gary; Hart, Nick; Wines, Marie

1989-01-01

323

Satellite and Ground Station Configuration for an Iranian National Satellite Communication System.  

National Technical Information Service (NTIS)

A communications satellite system for Iran was designed under contract to National Iranian Radio and Television. Summary results describe the alternatives considered and recommendation configurations for satellites and for major city and rural ground stat...

B. B. Lusignan

1976-01-01

324

Satellite communications systems and technology. Volume 2; Site Reports  

NASA Technical Reports Server (NTRS)

Volume 2 of the final report of the NASA/NSF Panel on Satellite Communications Systems and Technology is presented. It consists of the site reports from the panel's visits to satellite communications facilities and laboratories in Europe, Japan, and Russia.

Edelson, Burton I.; Pelton, Joseph N.; Bostian, Carles W.; Brandon, William T.; Chan, Vincent W. S.; Hager, E. Paul; Helm, Neil R.; Jennings, Raymond D.; Kwan, Robert K.; Mahle, Christoph E.; Miller, Edward F.; Riley, Lance

1993-01-01

325

Service Learning's Foothold in Communication Scholarship.  

ERIC Educational Resources Information Center

Considers how much of an impact service learning pedagogies have had among those who teach journalism and mass communication. Attempts to fill the research void by assessing the current state of this pedagogical movement within the journalism/mass communication discipline, and suggests that a formal process for incorporating service learning into…

Panici, Daniel; Lasky, Kathryn

2002-01-01

326

Communication Access to Health and Social Services  

ERIC Educational Resources Information Center

This article describes the efforts of a group of people in the United Kingdom at Connect-the communication disability network-to make health and social services more communicatively accessible to people with aphasia. The project involved listening to people with aphasia talk about their experiences with health and social care services and working…

Parr, Susie; Pound, Carole; Hewitt, Alan

2006-01-01

327

Consideration on minimizing the mass of communications equipments for the mobile communications satellite  

NASA Astrophysics Data System (ADS)

In mobile satellite communication, small and economical earth terminals can be employed if large satellite EIRP can be realized. In order to satisfy this requirement, a large antenna and high-power transponders are necessary; simultaneously reducing the mass of communication equipments in the satellite is required. In this paper, the relations between the total mass of communication equipment and the characteristics of the transponder and antenna in the satellite are derived. As a result, the optimum transponder output power, antenna diameter, and beam number which give large satellite EIRP with minimum mass of communication equipment, are obtained.

Dooi, Yoshikazu; Iso, Akio; Okubo, Naofumi; Sekine, Kenji; Baba, Yuichirou

328

New medical communication service for teleradiology application  

NASA Astrophysics Data System (ADS)

This paper presents a new medical communication service which supports consultation procedures in the modern tele-radiology. The system's perspectives and requirements are studied and analyzed by considering an interactive communication environment, which consists of geographically distributed entities working together and channels for either synchronous or asynchronous inter-communication.

Kotsopoulos, Stavros A.; Lymberopoulos, Dimitris C.; Anastassopoulos, George C.; Garatziotis, J.; Zoupas, Vasilios

1993-09-01

329

Controlling satellite communication system unwanted emissions in congested RF spectrum  

NASA Astrophysics Data System (ADS)

The International Telecommunication Union (ITU), a United Nations (UN) agency, is the agency that, under an international treaty, sets radio spectrum usage regulations among member nations. Within the United States of America (USA), the organization that sets regulations, coordinates an application for use, and provides authorization for federal government/agency use of the radio frequency (RF) spectrum is the National Telecommunications and Information Administration (NTIA). In this regard, the NTIA defines which RF spectrum is available for federal government use in the USA, and how it is to be used. The NTIA is a component of the United States (U.S.) Department of Commerce of the federal government. The significance of ITU regulations is that ITU approval is required for U.S. federal government/agency permission to use the RF spectrum outside of U.S. boundaries. All member nations have signed a treaty to do so. U.S. federal regulations for federal use of the RF spectrum are found in the Manual of Regulations and Procedures for Federal Radio Frequency Management, and extracts of the manual are found in what is known as the Table of Frequency Allocations. Nonfederal government and private sector use of the RF spectrum within the U.S. is regulated by the Federal Communications Commission (FCC). There is a need to control "unwanted emissions" (defined to include out-of-band emissions, which are those immediately adjacent to the necessary and allocated bandwidth, plus spurious emissions) to preclude interference to all other authorized users. This paper discusses the causes, effects, and mitigation of unwanted RF emissions to systems in adjacent spectra. Digital modulations are widely used in today's satellite communications. Commercial communications sector standards are covered for the most part worldwide by Digital Video Broadcast - Satellite (DVB-S) and digital satellite news gathering (DSNG) evolutions and the second generation of DVB-S (DVB-S2) standard, developed by the European Telecommunications Standards Institute (ETSI). In the USA, the Advanced Television Systems Committee (ATSC) has adopted Europe's DVB-S and DVB-S2 standards for satellite digital transmission. With today's digital modulations, RF spectral side lobes can extend out many times the modulating frequency on either side of the carrier at excessive power levels unless filtered. Higher-order digital modulations include quadrature phase shift keying (QPSK), 8 PSK (8-ary phase shift keying), 16 APSK (also called 12-4 APSK (amplitude phase shift keying)), and 16 QAM (quadrature amplitude modulation); they are key for higher spectrum efficiency to enable higher data rate transmissions in limited available bandwidths. Nonlinear high-power amplifiers (HPAs) can regenerate frequency spectral side lobes on input-filtered digital modulations. The paper discusses technologies and techniques for controlling these spectral side lobes, such as the use of square root raised cosine (SRRC) filtering before or during the modulation process, HPA output power back-off (OPBO), and RF filters after the HPA. Spectral mask specifications are a common method of the NTIA and ITU to define spectral occupancy power limits. They are intended to reduce interference among RF spectrum users by limiting excessive radiation at frequencies beyond the regulatory allocated bandwidth.The focus here is on the communication systems of U.S. government satellites used for space research, space operations, Earth exploration satellite services (EESS), meteorological satellite services (METSATS), and other government services. The 8025 to 8400 megahertz (MHz) X band can be used to illustrate the "unwanted emissions" issue. 8025 to 8400 MHz abuts the 8400 to 8450 MHz band allocated by the NTIA and ITU to space research for space-to-Earth transmissions such as receiving very weak Deep Space Network signals. The views and ideas expressed in this paper are those of the authors and do not necessarily reflect those of The Aerospace Corporation or The National Oceanic and Atmosphe

Olsen, Donald; Heymann, Roger

2007-09-01

330

Satellite Communications for Aeronautical Applications: Recent research and Development Results  

NASA Technical Reports Server (NTRS)

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.

Kerczewski, Robert J.

2001-01-01

331

The 18/30 GHz fixed communications system service demand assessment. Volume 1: Executive summary  

NASA Technical Reports Server (NTRS)

The total demand for voice, video, and data communications services, and satellite transmission services at the 4/6 GHz, 12/14 GHz, and 18/30 GHz frequencies is discussed. Major study objectives, overall methodology, results, and general observations about a satellite systems market characteristics and trends are summarized.

Gabriszeski, T.; Reiner, P.; Rogers, J.; Terbo, W.

1979-01-01

332

Low cost satellite land mobile service for nationwide applications  

NASA Technical Reports Server (NTRS)

A satellite land mobile system using mobile radios in the UHF band, and Ku-band Communications Routing Terminals (earth stations) for a nationwide connection from any mobile location to any fixed or mobile location, and from any fixed location to any mobile location is proposed. The proposed nationwide satellite land mobile service provides: telephone network quality (1 out of 100 blockage) service, complete privacy for all the users, operation similar to the telephone network, alternatives for data services up to 32 Kbps data rates, and a cost effective and practical mobile radio compatible with system sizes ranging from 10,000 to 1,000,000 users. Seven satellite alternatives (ranging from 30 ft diameter dual beam antenna to 210 ft diameter 77 beam antenna) along with mobile radios having a sensitivity figure of merit (G/T) of -15 dB/deg K are considered. Optimized mobile radio user costs are presented as a function of the number of users with the satellite and mobile radio alternatives as system parameters.

Weiss, J. A.

1978-01-01

333

Suitability of ANSI standards for quantifying communication satellite system performance  

NASA Technical Reports Server (NTRS)

A study on the application of American National Standards X3.102 and X3.141 to various classes of communication satellite systems from the simple analog bent-pipe to NASA's Advanced Communications Technology Satellite (ACTS) is discussed. These standards are proposed as means for quantifying the end-to-end communication system performance of communication satellite systems. An introductory overview of the two standards are given followed by a review of the characteristics, applications, and advantages of using X3.102 and X3.141 to quantify with a description of the application of these standards to ACTS.

Cass, Robert D.

1988-01-01

334

Multichannel demultiplexer/demodulator technologies for future satellite communication systems  

NASA Technical Reports Server (NTRS)

NASA-Lewis' Space Electronics Div. supports ongoing research in advanced satellite communication architectures, onboard processing, and technology development. Recent studies indicate that meshed VSAT (very small aperture terminal) satellite communication networks using FDMA (frequency division multiple access) uplinks and TDMA (time division multiplexed) downlinks are required to meet future communication needs. One of the critical advancements in such a satellite communication network is the multichannel demultiplexer/demodulator (MCDD). The progress is described which was made in MCDD development using either acousto-optical, optical, or digital technologies.

Ivancic, William D.; Budinger, James M.; Staples, Edward J.; Abramovitz, Irwin; Courtois, Hector A.

1992-01-01

335

Rain Attenuation and Doppler Shift Compensation for Satellite Communications  

Microsoft Academic Search

In high-speed multimedia satellite communication sys- tems, it is essential to provide high-quality, economical ser- vices by using efficient transmission schemes which can overcome channel impairments appearing in the satellite link. This paper introduces techniques to compensate for rain attenuation and the Doppler shift in the satellite com- munication link. An adaptive transmission technique with a control algorithm to adaptively

Sooyoung Kim Shin Shin; Kwangjae Lim Lim; Kwonhue Choi Choi; Kunseok Kang Kang

2002-01-01

336

Computer communications through telecommunications satellite systems - The NADIR project  

Microsoft Academic Search

Current developments in satellite digital communication in Europe are surveyed, and the status of the French NADIR project begun in 1980 is reported. The geographic coverage, transmission rates, propagation delays, broadcasting and multidestination channels, and error rates characteristic of present satellite systems are discussed, and the specific performance parameters of the Telecom-1 system, comprising three geosynchronous satellites (one operational and

J.-L. Grange

1983-01-01

337

Man-Made Moons: Satellite Communications for Schools.  

ERIC Educational Resources Information Center

In an effort to prepare teachers for the coming changes in education caused by the rapidly developing communication satellite technology, this monograph offers a non-technical background to this new development. It begins by explaining the importance of such satellites and offers a layman's guide to the technology of satellite systems. It reviews…

Grayson, Lawrence P.; And Others

338

Multi-carrier network-centric satellite communications modem design  

Microsoft Academic Search

The paper presents concepts for network-centric communications that are matched to the planned wideband gapfiller satellite system (WGSS) and other transponder based satellite communications. Gapfiller satellites will digitally transpond uplinks and downlinks between X- and Ka-band beams using multiple 125 MHz transponders that can be subchannelized into as many as forty-eight 2.6 MHz band segments. The proposed concept is a

H. I. Paul

2002-01-01

339

15 CFR 950.8 - Satellite Data Services Division (SDSD).  

Code of Federal Regulations, 2010 CFR

...Division (SDSD). The Satellite Data Services Division...and earth resources satellite data to other users...purposes (i.e. , weather forecasting) have...SKYLAB missions. (a) Satellite data available from...spacecraft; much of the imagery gathered by...

2009-01-01

340

15 CFR 950.8 - Satellite Data Services Division (SDSD).  

Code of Federal Regulations, 2010 CFR

...Division (SDSD). The Satellite Data Services Division...and earth resources satellite data to other users...purposes (i.e. , weather forecasting) have...SKYLAB missions. (a) Satellite data available from...spacecraft; much of the imagery gathered by...

2010-01-01

341

Study of EVA Operations Associated with Satellite Services.  

National Technical Information Service (NTIS)

Extravehicular mobility unit (EMU) factors associated with satellite servicing activities are identified and the EMU improvements necessary to enhance satellite servicing operations are outlined. Areas of EMU capabilities, equipment and structural interfa...

J. O. Nash R. D. Wilde

1982-01-01

342

Mobile communications satellite antenna flight experiment definition  

NASA Astrophysics Data System (ADS)

There are classes of application that collectively require a variety of different types of large-aperture space antennas. Fortunately, there are a number of different deployable antenna concepts that have tremendous potential for such applications. However, these concepts vary in maturity from flight-proven designs to extremely innovative configuration definitions. But these promising concepts lack sufficient demonstrations of maturity to be seriously considered in the large size range for immediate application. The reason for this situation is an extremely limited space flight data base in addition to the technical limitations and great costs associated with meaningful ground testing of large, flexible, precision space structures. The user community of such structures, especially the commercial organizations interested in providing a Mobile Communications Satellite (MSAT) on a profit-making basis, will require significant demonstrations of technology readiness prior to application commitment. Such demonstrations will probably be based on a combination of extensive ground testing and subsequent space flight experiments. The Communications Division of the National Aeronautics and Space Administration (NASA) Office of Space Science and Applications sponsored a study at the Jet Propulsion Laboratory (JPL) to determine the technical feasibility and cost of a Shuttle-based flight experiment specifically intended for the MSAT commercial user community. The experiment will include demonstrations of technology in the areas of radio frequency (RF), sensing and control, and structures. This paper summarizes the results of the structural subsystem study. These results include experiment objective and technical approach, experiment structural description, structure/environment interactions, structural characterization, thermal characterization, structural measurement system, and experiment functional description.

Freeland, Robert E.

343

78 FR 36725 - Numbering Policies for Modern Communications; IP-Enabled Services; Telephone Number Requirements...  

Federal Register 2010, 2011, 2012, 2013

...interconnected VoIP providers to obtain phone numbers directly from the number administrators...will hinder or prevent call routing or tracking, and how such complications can be prevented...telecommunications services, such as satellite tracking, communications telemetry, and...

2013-06-19

344

A Hybrid Satellite-Terrestrial Approach to Aeronautical Communication Networks  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

345

78 FR 31576 - Enforcement Proceeding; Certain Two-Way Global Satellite Communication Devices, System and...  

Federal Register 2010, 2011, 2012, 2013

...Proceeding; Certain Two-Way Global Satellite Communication Devices, System and Components...importation of certain two-way global satellite communication devices, system and components...after importation any two-way global satellite communication devices, system,...

2013-05-24

346

Personal communication services: expanding the freedom to communicate  

Microsoft Academic Search

Discusses the potential of personal communication services, which allows communication from person to person, regardless of physical location, to change the way people live and work. The problem of spectrum scarcity is examined, and some proposals for increasing the efficiency of spectrum use are presented

S. Ginn

1991-01-01

347

Cockpit weather graphics using mobile satellite communications  

NASA Astrophysics Data System (ADS)

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

Seth, Shashi

348

Cockpit weather graphics using mobile satellite communications  

NASA Technical Reports Server (NTRS)

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

Seth, Shashi

1993-01-01

349

47 CFR 73.667 - TV subsidiary communications services.  

Code of Federal Regulations, 2010 CFR

...subsidiary communications services that...private radio in nature are...Subsidiary communications services are of a secondary nature under the...to leased communications services transmitted...broadcast nature....

2009-10-01

350

47 CFR 73.295 - FM subsidiary communications services.  

Code of Federal Regulations, 2013 CFR

...FM subsidiary communications services that are common carrier in nature are subject...c) Subsidiary communications services are of a secondary nature under the authority...to provide such communications services...

2013-10-01

351

47 CFR 73.295 - FM subsidiary communications services.  

Code of Federal Regulations, 2010 CFR

...FM subsidiary communications services that are common carrier in nature are subject...c) Subsidiary communications services are of a secondary nature under the authority...to provide such communications services...

2009-10-01

352

47 CFR 73.667 - TV subsidiary communications services.  

Code of Federal Regulations, 2013 CFR

...subsidiary communications services that...private radio in nature are...Subsidiary communications services are of a secondary nature under the...to leased communications services transmitted...broadcast nature....

2013-10-01

353

Power beaming to communication satellites in GEO.  

National Technical Information Service (NTIS)

Batteries normally provide power to geosynchronous satellites during earth eclipse 90 times each year, but the heavy charge-discharge cycle decreases their life expectancy. Battery life, and thus satellite life, could be extended by providing power during...

R. M. Morgan R. J. Lipinski

1992-01-01

354

The ESA technological development activity for domestic communications satellite systems  

NASA Astrophysics Data System (ADS)

Domestic and rural satellite communications, when compared to more traditional satellite systems such as Intelsat and Eutelsat, present different system requirements which result in different technological solutions both for the space segment and the ground segment. In view of preparing European industry to be competitive in an international 'Call for Tenders' expected for such systems, especially from less developed countries, the European Space Agency started in 1982 a program of technological development of specific components, subsystems, and systems described in this communication. After introducing background concepts of Domestic Communication Satellite Systems, the article reviews the technological developments in both the space segment and the earth segment.

Bichi, A. F.

1986-10-01

355

Satellite communications application to Pacific countries above Ku band  

NASA Technical Reports Server (NTRS)

An application of satellite communications above the Ku band to the Pacific region is described, focusing on: (1) Lightsat system and (2) a high capacity satellite system. A small geostationary satellite system using Ku band for the Federated States of Micronesia is shown as an example. A concept of multi-gigabits/second high capacity communications system using two satellites in the Ka band is described. The onboard bit-by-bit processing is very useful in the low link margin environment due to rain attenuation. These topics were obtained by the Asia Pacific Telecommunications Study granted by NASA conducted by the University of Colorado at Boulder.

Iida, Takashi

1992-01-01

356

Ultra high frequency follow-on communications satellite system  

NASA Astrophysics Data System (ADS)

The existing constellation of UHF communications satellites (LEASAT and FLTSAT) provide key command and control links for mobile forces of the DoD and other government agencies. The UHF Follow-On satellite program will provide for a new generation of communications satellites to replace the existing ones as they reach the end of their life cycle beginning in 1992. Continued coverage is required for both peacetime and crisis environments, and must be maintained indefinitely. An eight-satellite UFO constellation (two per coverage area) will replenish the existing FLTSATCOM constellation.

Hassien, Michael J.

1992-03-01

357

Engineering calculations for communications satellite systems planning  

NASA Technical Reports Server (NTRS)

A procedure is described that was used to calculate minimum required satellite separations based on total link carrier to interference requirements. Also summarized are recent results with a switching algorithm for satellite synthesis problems. Analytic solution value bounds for two of the satellite synthesis models studied are described. Preliminary results from an empirical study of alternate mixed integer programming models for satellite synthesis are presented. Research plans for the near future are discussed.

Reilly, Charles H.; Walton, Eric K.; Kohnhorst, Paul

1987-01-01

358

Satellite communication and navigation for mobile users  

NASA Technical Reports Server (NTRS)

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

Bernstein, S. L.

1972-01-01

359

Intelligent network requirements for personal communications services  

Microsoft Academic Search

It is shown that a moderate set of capabilities within the service switching point (SSP), service control point (SCP), and intelligent peripheral (IP), which are the intelligent network (IN) components directly responsible for the real-time execution and control of end-user services, can engender a wide range of end-user personal communication service (PCS) features. These capabilities could be used as the

J. Homa; S. Harris

1992-01-01

360

Caribbean Regional Communications Service Study. Report.  

National Technical Information Service (NTIS)

A follow-up to a limited experiment with the use of satellites in education and public service conducted by the University of the West Indies (UWI) in 1978, this study explores the feasibility of providing a number of services, which would include an exte...

G. C. Lalor

1982-01-01

361

Satellite servicing mission preliminary cost estimation model  

NASA Technical Reports Server (NTRS)

The cost model presented is a preliminary methodology for determining a rough order-of-magnitude cost for implementing a satellite servicing mission. Mission implementation, in this context, encompassess all activities associated with mission design and planning, including both flight and ground crew training and systems integration (payload processing) of servicing hardward with the Shuttle. A basic assumption made in developing this cost model is that a generic set of servicing hardware was developed and flight tested, is inventoried, and is maintained by NASA. This implies that all hardware physical and functional interfaces are well known and therefore recurring CITE testing is not required. The development of the cost model algorithms and examples of their use are discussed.

1987-01-01

362

Technology programs and related policies - Impacts on communications satellite business ventures  

NASA Technical Reports Server (NTRS)

The DOMSAT II stochastic communication satellite business venture financial planning simulation model is described. The specification of business scenarios and the results of several analyses are presented. In particular, the impacts of NASA on-orbit propulsion and power technology programs are described. The effects of insurance rates and self-insurance and of the use of the Space Shuttle and Ariane transportation systems on a typical fixed satellite service business venture are discussed.

Greenberg, J. S.

1985-01-01

363

Optical data communication for Earth observation satellite systems  

NASA Astrophysics Data System (ADS)

The current development status of optical communication engineering in comparison to the conventional microwave systems and the different configurations of the optical data communication for Earth observation satellite systems are described. An outlook to future optical communication satellite systems is given. During the last decade Earth observation became more and more important for the extension of the knowledge about our planet and the human influence on nature. Today pictures taken by satellites are used, for example, to discover mineral resources or to predict harvest, crops, climate, and environment variations and their influence on the population. A new and up to date application for Earth observation satellites can be the verification of disarmament arrangements and the control of crises areas. To solve these tasks a system of Earth observing satellites with sensors tailored to the envisaged mission is necessary. Besides these low Earth orbiting satellites, a global Earth observation system consists of at least two data relay satellites. The communication between the satellites will be established via Inter-Satellite Links (ISL) and Inter-Orbit Links (IOL). On these links, bitrates up to 1 Gbit/s must be taken into account. Due to the increasing scarcity of suitable frequencies, higher carrier frequencies must probably be considered, and possible interference with terrestrial radio relay systems are two main problems for a realization in microwave technique. One important step to tackle these problems is the use of optical frequencies for IOL's and ISL's.

Fischer, J.; Loecherbach, E.

1991-10-01

364

Design and Implementation of a Lunar Communications Satellite and Server for the 2012 SISO Smackdown  

NASA Technical Reports Server (NTRS)

Last year, the Simulation Interoperability Standards Organization (SISO) inaugurated the now annual High Level Architecture (HLA) Smackdown at the Spring Simulation Interoperability Workshop (SIW). A primary objective of the Smackdown event is to provide college students with hands-on experience in the High Level Architecture (HLA). The University of Alabama in Huntsville (UAHuntsville) fielded teams in 2011 and 2012. Both the 2011 and 2012 smackdown scenarios were a lunar resupply mission. The 2012 UAHuntsville fielded four federates: a communications network Federate called Lunar Communications and Navigation Satellite Service (LCANServ) for sending and receiving messages, a Lunar Satellite Constellation (LCANSat) to put in place radios needed by the communications network for Line-Of-Sight communication calculations, and 3D graphical displays of the orbiting satellites and a 3D visualization of the lunar surface activities. This paper concentrates on the first two federates by describing the functions, algorithms, the modular FOM, experiences, lessons learned and recommendations for future Smackdown events.

Bulgatz, Dennis; Heater, Daniel; O'Neal, Daniel A.; Norris, Bryan; Schricker, Bradley C.

2012-01-01

365

INTEGRATED QUALITY OF SERVICE FOR MULTIMEDIA COMMUNICATIONS  

Microsoft Academic Search

The integration of distributed multimedia systems support into a communications architecture encompassing the new multiservice networks poses significatu challenges. A key observation about the new environment is that Quality of Service (QOS) provides a unifying theme around which most of the new communications requirements can be grouped. For applications relying on the transfer of multimedia information, and in particular continuous

Andrew Campbell; Geoff Coulson; Francisco Garcla; David Hutchison; Helmut Leopold

1992-01-01

366

Integrated Quality of Service for Multimedia Communications  

Microsoft Academic Search

The integration of distributed multimedia systems support into a communications architecture encompassing the new multiservice networks poses significant challenges. A key observation about the new environment is that Quality of Service (QOS) provides a unifying theme around which most of the new communications requirements can be grouped. For applications relying on the transfer of multimedia information, and in particular continuous

Andrew T. Campbell; Geoff Coulson; Francisco Garcia; David Hutchison; Helmut Leopold

1993-01-01

367

Personal communications services: the next technological revolution  

Microsoft Academic Search

The US Federal Communications Commission (FCC) has issued a Notice of Inquiry (NOI) to consider whether to allocate frequencies for personal communications services (PCS), the particular PCS offerings to authorize, the technical standards that licensees should follow, and the regulatory policies tha should govern PCS operations, including who may be eligible for PCS licenses. An overview is given of the

R. M. Singer; D. A. Irwin

1991-01-01

368

Integrated technology services publications and communications strategy  

Microsoft Academic Search

In September 2006, Integrated Technology Services (ITS) at the University of New Brunswick (UNB) refocused their Publications and Communications position in an effort to better communicate their mission, vision, goals, and values to the UNB community and external audiences. ITS recognized that the UNB community did not understand the importance of what ITS does, how ITS supports UNB's mission and

Melissa R. Hannah

2007-01-01

369

Beyond the Ionosphere: Fifty Years of Satellite Communication  

NASA Technical Reports Server (NTRS)

The three overlapping stages of satellite communications development outlined provide the three-part framework for the organization of the papers contained in this book. Part 1, 'Passive Origins,' treats the first stage of satellite communications development, extending from the 1940s into the early 1960s, when passive artificial and natural satellites funded by the military and private enterprise established the field. Part 2, 'Creating the Global, Regional, and National Systems,' addresses events that constituted the second stage of development. Early in this stage, which stretched from the 1960s into the 1970s, satellite systems began to make their appearance in the United States, while domestic and international efforts sought to bring order to this new but chaotic, field in the form of Comsat and Intelsat. Part 3, 'The Unfolding of the World System,' explores the development of satellite communications in the remainder of the world, with a strong emphasis on Asia.

Butrica, Andrew J. (Editor)

1997-01-01

370

Beyond the Ionosphere: Fifty Years of Satellite Communication.  

National Technical Information Service (NTIS)

Partial Contents: Radio Versus Cable: 'International Telecommunications Before Satellites'; 'Moon in Their Eyes: Moon Communication Relay at the Naval Research Laboratory, 1951-1962'; 'Moon Relay Experiments at Jodrell Bank'; 'Something of Value: Echo and...

A. J. Butrica

1997-01-01

371

Project Universe - Local area networks and satellite communications  

NASA Astrophysics Data System (ADS)

A high-speed digital communications system is discussed in which a satellite is used to link a number of local area networks which interconnect a variety of computer facilities. The advantages of satellite communications compared with terrestrial links are described, together with a historical survey of the use of the Orbital Test Satellite (OTS) for data experiments. A description of Project Universe is given and the purpose of the project is described along with a more detailed description of the elements that make up the network such as satellite earth terminals, communication rings and terrestrial links. Future developments of such systems and their use as a means of business communication are considered, in particular, the factors affecting their growth, emphasis being placed on the specification and cost of equipment.

Ackroyd, B. R.

1983-07-01

372

Homodyne BPSK-based optical inter-satellite communication links  

NASA Astrophysics Data System (ADS)

Summer 2007, Tesat will verify laser communication terminals based on homodyne BPSK (binary phase shift keying) in-orbit. A 5.625 Gbps LEO-LEO laser communication link, established between the German satellite TerraSAR-X and the US satellite NFIRE, shall demonstrate the performance and advantages of laser communication. End of 2006, a further program has been kicked-off to demonstrate the performance of ~2 Gbps LEO-GEO laser communication links. The link is part of a data relais from the German LEO satellite TanDEM-X via a Geo satellite to ground. The LEO-to-GEO laser commmunication link can be extended to further ~2 Gpbs GEO-GEO, and GEO-to-ground links.

Lange, Robert; Smutny, Berry

2007-03-01

373

Experiments on maritime satellite communications using ETS-V  

NASA Astrophysics Data System (ADS)

Mobile Satellite Communication Systems with small mobile earth stations have been studied by many organizations for establishing general mobile satellite systems which include land, maritime and aeronautical mobile users. Communications Research Laboratory has been making researches in a digital mobile satellite communication system for small vessels and developing a small ship earth station with a 40 cm antenna. On-board experiments of the ship earth station are performed using ETS-V satellite in the Indian, North Pacific and South Pacific Ocean regions. The outline of the experiments is described and the results are discussed concerning bit error performance, fading due to sea-surface reflection, the fading reduction technique, shadowing due to ship superstructure, etc. During the experiments a stable communication link with digital telephony was successfully maintained with some effects of fading at very low elevation angles and some shadowing.

Ikegami, Tetsushi; Wakana, Hiromitsu; Kawamata, Fumio; Ide, Toshiyuki; Matsumoto, Yasushi

1990-03-01

374

Field experiment on digital maritime satellite communication systems  

NASA Astrophysics Data System (ADS)

The system configuration and results are presented for a field experiment on digital maritime satellite communication systems carried out in December 1986, using the INMARSAT Indian Ocean satellite (INTELSAT-V with maritime communication subsystem). The digital communication subsystem used for the experiment consists of a 16-kb/s APC (adaptive predictive coding) voice codec and a rate-3/4 FEC (forward-error correcting) codec using Viterbi decoding for punctured code to utilize the satellite power and bandwidth as efficiently as possible. For the ship earth station, a high-gain antenna with G/T (gain to temperature) of -4 dBK and a low-gain antenna with G/T of -10 dBK were used. The effectiveness of the digital ship earth station system was verified under the actual maritime satellite communication environment with multipath fading.

Yasuda, Yutaka; Ohashi, Masayoshi; Sugaya, Fumiaki; Hirata, Yasuo; Okinaka, Hideo

375

Global disaster satellite communications system for disaster assessment and relief coordination  

NASA Technical Reports Server (NTRS)

Global communication requirements for disaster assistance are analyzed in the light of operationally feasible satellite system concepts and associated system parameters. Present and planned commercially available systems are considered, together with an assessment of the associated global disaster communication yearly service costs. It is concluded that a likely number of transportable terminals required for long distance relief communications activities would be less than 10, with the transportation costs not expected to exceed 25% of the annual systems' cost. Consequently, no sound economic justification is seen for ground terminal development for the global disaster communications system.

Leroy, B. E.

1979-01-01

376

The 30/20 GHz fixed communications systems service demand assessment. Volume 2: Main report  

NASA Technical Reports Server (NTRS)

A forecast of demand for telecommunications services through the year 2000 is presented with particular reference to demand for satellite communications. Estimates of demand are provided for voice, video, and data services and for various subcategories of these services. The results are converted to a common digital measure in terms of terabits per year and aggregated to obtain total demand projections.

Gamble, R. B.; Seltzer, H. R.; Speter, K. M.; Westheimer, M.

1979-01-01

377

Global Earth observation using modern communications satellite techniques  

NASA Astrophysics Data System (ADS)

The various properties of geostationary and low Earth orbiting satellites are discussed. Main emphasis is given to satellite interconnection techniques, due to the importance of Interorbit and Intersatellite Links (IOL and ISL) in a global and efficient Earth observation satellite system. Conventional microwave as well as modern optical techniques are possible candidates for these links. In this frame, a High Power Diode Transmitter (HPDT) is presented. As an outlook to a future worldwide communication scenario the integration of Earth observation satellites in an information satellite (Infosat) system is raised.

Loecherbach, E.; Eckhardt, G.

1992-07-01

378

Global maritime mobile service via satellite - The INMARSAT system now and in the future  

NASA Astrophysics Data System (ADS)

The business and technical aspects of the INMARSAT (International Maritime Satellite Organization) system are reviewed along with its present capabilities and services and future developments now being considered. The initial phase of maritime mobile satellite communications began with the introduction by the U.S. of the Marisat system in 1976, satisfying a commitment made by COMSAT (Communications Satellite Corp.) in 1973 to provide a maritime satellite service. The Marisat Consortium, spun off by COMSAT, launched three satellites in 1973 - one to serve shipping in the Atlantic, one for the Pacific, and the third as a spare; the spare was subsequently positioned over the Indian Ocean so that the three provided almost global coverage. Each satellite was served by a coast earth station with a 13-m antenna; satellite-earth station links operated in the 6 and 4-GHz bands and the ship-satellite links were at 1.5 and 1.6 GHz. Superceding the limited Marisat system, the INMARSAT Organization, established in July 1979 and first in service on Feb. 1, 1982, now provides communications through a system of Marecs, Intelsat-V, and Marisat satellites. With 41 Signatories by mid-1985, the organization consists of an Assembly, a Council, and a Directorate. Services provided include: telephone; facsimile; low-speed data; high-speed data; telex; telegram; distress, urgency and safety communications; shore-to-ship group calls; various information and assistance services. Coast earth stations, ship earth stations, network coordination stations, and the London headquarters and operations control center are described. Future developments will include an expanded capacity network, digital services, and a role in the Future Global Maritime Distress and Safety System that will use radio beacons that will automatically transmit distress messages to land-based emergency centers in the event of a disaster at sea.

Snowball, A. E.

1986-06-01

379

Application of advanced on-board processing concepts to future satellite communications systems  

NASA Technical Reports Server (NTRS)

An initial definition of on-board processing requirements for an advanced satellite communications system to service domestic markets in the 1990's is presented. An exemplar system architecture with both RF on-board switching and demodulation/remodulation baseband processing was used to identify important issues related to system implementation, cost, and technology development.

Katz, J. L.; Hoffman, M.; Kota, S. L.; Ruddy, J. M.; White, B. F.

1979-01-01

380

Development of rain attenuation and rain rate maps for satellite communications system design in Greece  

Microsoft Academic Search

Using six (6) years of point rainfall data from several locations in Greece, which were obtained from the National Hellenic Meteorological Service (NHMS), the statistics of rainfall for various percentages of time for the average year are derived. Using the originally derived rainfall statistics, accurate rain rate and attenuation maps are developed for facilitating satellite communications systems design in Greece.

Anastassios D Papatsoris; Konstantinos Polimeris; Athanasia A Lazou

2008-01-01

381

Enhancing End-to-End Performance of Information Services Over Ka-Band Global Satellite Networks  

NASA Technical Reports Server (NTRS)

The Internet has been growing at a rapid rate as the key medium to provide information services such as e-mail, WWW and multimedia etc., however its global reach is limited. Ka-band communication satellite networks are being developed to increase the accessibility of information services via the Internet at global scale. There is need to assess satellite networks in their ability to provide these services and interconnect seamlessly with existing and proposed terrestrial telecommunication networks. In this paper the significant issues and requirements in providing end-to-end high performance for the delivery of information services over satellite networks based on various layers in the OSI reference model are identified. Key experiments have been performed to evaluate the performance of digital video and Internet over satellite-like testbeds. The results of the early developments in ATM and TCP protocols over satellite networks are summarized.

Bhasin, Kul B.; Glover, Daniel R.; Ivancic, William D.; vonDeak, Thomas C.

1997-01-01

382

Advanced Technologies and Satellite Services for Enhancing Space Surveillance  

NASA Astrophysics Data System (ADS)

Space-based systems are becoming part of our infrastructure and our dependency on space-based services has grown. Therefore, the assured availability and operational readiness of space-based services is essential, undoubtedly. However, satellites are subject to a variety of damaging effects and potential threats. These are mostly caused by an increasingly crowded region of outer space, by space weather including solar events and, unfortunately, even attacks on space systems which are no longer sience fiction as impressively demonstrated in 2007 with the Chinese anti-satellite test and the intercept of USA-193 in 2008. Today, German armed forces use several space services primarily for reconnaissance, communications and navigation. As a matter of fact, Germany`s sovereignty and national security depend on the availability of multiple space services. This led the Federal Ministry of Defence to set up a dedicated military Space Situational Awareness Centre at Kalkar/Uedem, Germany, as a significant contribution to a national preventive security. This paper provides information on a range of technical issues related to space assets that are important for anyone involved in the debate over space security and gives a brief survey of the German SSA program. The paper deals with a subset of feasible man-made threats and its fatal effects on space assets. Furthermore, the preliminary conceptual design of an onboard sensor suitable for the instant detection of the previously described types of threats is presented. Finally, advanced technologies for the near real-time transfer of data are highlighted.

2010-08-01

383

Engineering calculations for communications satellite systems planning  

NASA Technical Reports Server (NTRS)

The final phase of a satellite synthesis project is described. Several methods for generating satellite positionings with improved aggregate carrier to interference characteristics were studied. Two general methods for modifying required separation values are presented. Also, two methods for improving aggregate carrier to interference (C/I) performance of given satellite synthesis solutions are presented. A perturbation of the World Administrative Radio Conference (WARC) synthesis is presented.

Walton, E.; Aebker, E.; Mata, F.; Reilly, C.

1991-01-01

384

Secure Satellite Communication Systems Design with Individual Secrecy Rate Constraints  

Microsoft Academic Search

In this paper, we study multibeam satellite secure communication through physical (PHY) layer security techniques, i.e., joint power control and beamforming. By first assuming that the channel state information (CSI) is available and the beam- forming weights are fixed, a novel secure satellite system design is investigated to minimize the transmit power with individual se- crecy rate constraints. An iterative

Jiang Lei; Zhu Han; Maria Angeles Vázquez-Castro; Are Hjørungnes

2011-01-01

385

The cost structure of personal communication services  

Microsoft Academic Search

The costs of constructing and operating personal communications service (PCS) systems are examined to assess the potential spectrum requirements of these services. The cost model developed for this task estimated the costs of building and operating a new PCS network, as well as the costs of providing PCSs using existing infrastructure such as the telephone, cable television, and cellular telephone

David P. Reed

1993-01-01

386

Distributed call processing for personal communications services  

Microsoft Academic Search

The authors present a control architecture, procedures, and a signaling system to support advanced personal communication services (PCS). They describe the current cellular system architecture, and its algorithms and data management schemes for providing services. They present review how current cellular systems operate with a focus on mobility management and call and connection control. The benefits of this architecture include

Thomas F. La Porta; Malathi Veeraraghavan; Philip A. Treventi; Ramachandran Ramjee

1995-01-01

387

Some Features of Maritime Telex Service Communication.  

ERIC Educational Resources Information Center

This article analyzes four categories of English-language maritime telex service communication: (1) standard, system- generated messages; (2) standard procedures for transmitting messages; (3) nonstandard messages related to maritime mobile radio service (MMRS); and (4) nonstandard messages related to the organization, procedures, or equipment of…

Johnson, Barry

1995-01-01

388

Domestic multibeam satellite communication system design and performance  

Microsoft Academic Search

The design and performance of a 1000-kg-class Ka\\/S-band multibeam satellite communications system for Japan are discussed. The Ka-band fixed multibeam satellite system includes a 4-beam antenna and 14 transponders switched at the intermediate frequency stage; the S-band mobile satellite system includes a 5-beam antenna and 5 transponders. The output power of the transponders is 10 W for the Ka-band and

Kazuhiro Miyauchi; Heiichi Yamamoto; Kozo Morita; Ken Kondo; Tetsuo Yasaka

1986-01-01

389

A multi-purpose satellite service at 20/30 GHz - Opportunities and challenges  

NASA Astrophysics Data System (ADS)

The suitability of developing high-frequency bands is evaluated with particular attention given to the use of the 20/30-GHz band for satellite voice, data, and video communications. Crowding in the C- and Ku-band frequencies allocated to fixed-satellite services is examined in the light of continuing growth, and the benefits of establishing general-satellite services (GSSs) are listed. NASA's ACTS program and private GSS systems are delineated and shown to offer high-data-rate fixed-communications antennas and technologies suitable for multiple services. The Norstar satellite is described as an example of a GSS system, and the technical characteristics are given. In spite of technical, operational, and regulatory challenges presented by the development of GSS systems, a GSS allocation can enable the International Telecommunications Union to be proactive in its spectrum/orbit allocations.

Taylor, Leslie

1992-03-01

390

Communications Satellites: Looking Down the Road.  

ERIC Educational Resources Information Center

The first phase of the satellite component of a worldwide information grid is over. The real problems are beginning now with the evolution of technology that will beam specialized transmissions from higher-powered satellites into smaller antennae perched on ships, airplanes, and rooftops. This is another matter politically, economically, and…

Dizard, Wilson P.

391

Use of advanced solar cells for commercial communication satellites  

NASA Technical Reports Server (NTRS)

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

Bailey, Sheila G.; Landis, Geoffrey A.

1995-01-01

392

Use of advanced solar cells for commercial communication satellites  

NASA Astrophysics Data System (ADS)

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

Bailey, Sheila G.; Landis, Geoffrey A.

1995-03-01

393

Use of advanced solar cells for commerical communication satellites  

NASA Astrophysics Data System (ADS)

The current generation of communications satellites are located primarily in geosynchronous Earth orbit (GEO). Over the next decade, however, a new generation of communications satellites will be built and launched, designed to provide a world-wide interconnection of portable telephones. For this mission, the satellites must be positioned in lower polar- and near-polar orbits. To provide complete coverage, large numbers of satellites will be required. Because of the required number of satellites decreases as the orbital altitude is increased, fewer satellites would be required if the orbit chosen were raised from Low to intermediate orbit. However, in intermediate orbits, satellites encounter significant radiation due to trapped electrons and protons. Radiation tolerant solar cells may be necessary to make such satellites feasible. We analyze the amount of radiation encountered in low and intermediate polar orbits at altitudes of interest to next-generation communication satellites, calculate the expected degradation for silicon, GaAs, and InP solar cells, and show that the lifetimes can be significantly increased by use of advanced solar cells.

Landis, Geoffrey A.; Bailey, Sheila G.

1995-01-01

394

An overview of the communications technology satellite project: Executive summary  

NASA Technical Reports Server (NTRS)

An overview of the Communications Technology Satellite (CTS) project, a joint venture between NASA and the Canadian Department of Communications is given. A brief technical description of the CTS spacecraft and its cognate hardware and operations, a history of the CTS project, and a list of the CTS experiments and demonstrations conducted during the course of the project are given.

Rapp, W.; Ogden, D.; Wright, D.

1982-01-01

395

Communication satellite technology: State of the art and development opportunities  

NASA Technical Reports Server (NTRS)

Opportunities in communication satellite technology are identified and defined. Factors that tend to limit the ready availability of satellite communication to an increasingly wide group of users are evaluated. Current primary limitations on this wide utilization are the availability of frequency and/or synchronous equatorial satellite positions and the cost of individual user Earth terminals. The former could be ameliorated through the reuse of frequencies, the use of higher frequency bands, and the reduction of antenna side lobes. The latter limitation requires innovative hardware, design, careful system design, and large scale production.

Woodford, J. B. (compiler)

1978-01-01

396

R and D limited partnerships (possible applications in advanced communications satellite technology experiment program)  

NASA Technical Reports Server (NTRS)

Typical R&D limited partnership arrangements, advantages and disadvantages of R&D limited partnership (RDLPs) and antitrust and tax implications are described. A number of typical forms of RDLPs are described that may be applicable for use in stimulating R&D and experimental programs using the advanced communications technology satellite. The ultimate goal is to increase the rate of market penetration of goods and/or services based upon advanced satellite communications technology. The conditions necessary for these RDLP forms to be advantageous are outlined.

1985-01-01

397

Leo Satellite Communication through a LEO Constellation using TCP/IP Over ATM  

NASA Technical Reports Server (NTRS)

The simulated performance characteristics for communication between a terrestrial client and a Low Earth Orbit (LEO) satellite server are presented. The client and server nodes consist of a Transmission Control Protocol /Internet Protocol (TCP/IP) over ATM configuration. The ATM cells from the client or the server are transmitted to a gateway, packaged with some header information and transferred to a commercial LEO satellite constellation. These cells are then routed through the constellation to a gateway on the globe that allows the client/server communication to take place. Unspecified Bit Rate (UBR) is specified as the quality of service (QoS). Various data rates are considered.

Foore, Lawrence R.; Konangi, Vijay K.; Wallett, Thomas M.

1999-01-01

398

Bit Error Rate Evaluation of a Spectrally Efficient CDMA Scheme for Geostationary Satellite Communications  

Microsoft Academic Search

Spectrally efficient CDMA (SE-CDMA) is a multiple access and modulation scheme proposed for multibeam geostationary communications satellites that provides fixed service directly to the end users. The SE-CDMA is designed to meet the service requirements for high spectral efficiency and low bit error rate (BER) given the on-board power limitations. Its implementation consists of a concatenated Reed-Solomon\\/turbo channel encoder, of

Diakoumis P. Gerakoulis; Evaggelos Geraniotis

2000-01-01

399

Human interfaces for robotic satellite servicing  

NASA Astrophysics Data System (ADS)

On-orbit servicing (OOS) is growing in importance for the sustainment of certain satellite systems. Although it is more economical to replace satellites in many cases, OOS could be beneficial, or even critical, for more expensive satellites such as Space-Based Laser and constellations such as the Global Positioning System. Some future OOS missions including refueling and modular component replacement will be highly autonomous, but there will still be a need for humans to supervise and to recover when unexpected situations arise. Non-routine tasks such as damage repair or optics cleaning will likely require a more significant level of human control. The human interfaces for such activities can include body tracking systems, three-dimensional audio and video, tactile feedback devices, and others. This paper will provide some insights into when and at what level human interaction may be needed for OOS tasks. Example missions will be discussed and the argument will be made that human interfaces are important even for primarily autonomous missions. Finally some current research efforts within NASA, academia and the military will be discussed including research being conducted in the Air Force Research Laboratory at Wright-Patterson Air Force Base.

Ianni, John; Repperger, Daniel; Baker, Robert W.; Williams, Robert L.

2002-06-01

400

Land vehicle antennas for satellite mobile communications  

NASA Technical Reports Server (NTRS)

The RF performance, size, pointing system, and cost were investigated concepts are: for a mechanically steered 1 x 4 tilted microstrip array, a mechanically steered fixed-beam conformal array, and an electronically steered conformal phased array. Emphasis is on the RF performance of the tilted 1 x 4 antenna array and methods for pointing the various antennas studied to a geosynchronous satellite. An updated version of satellite isolations in a two-satellite system is presented. Cost estimates for the antennas in quantities of 10,000 and 100,000 unites are summarized.

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

1985-01-01

401

High capacity satellite communication system and key technologies  

NASA Astrophysics Data System (ADS)

A high-capacity satellite communication system for Japan, with multiple beams and key technologies for onboard equipment, is described. The system will provide trunk transmission, digital business communication, and mobile communication. Advantages of the multibeam system include increased transmission capacity, reduction in earth-station antenna diameter, and frequency reuse. Onboard technologies discussed include cluster-feed horn design, reflector deployment, antenna pointing control (accurate to 0.015 degree with 0.3-degree spot width for the 12 beams), satellite switch, and onboard receiver and transmitter.

Nagai, Y.; Okasaka, S.; Nakagawa, K.

402

EHF (28/19 GHz) personal communications satellite terminal development  

NASA Technical Reports Server (NTRS)

The concept of communicating on a personal basis using a small terminal has been investigated globally from many different applications and technology perspectives. Applications range from terrestrial handheld communicators for paging, cellular, zone voice/data networks, etc., to satellite terminals of pocket dimensions for voice/low speed data or similar terminals using larger antennas for VSAT, news gathering (30 cm), and video (1.2 m). A brief status of some developments in the satellite personal communications at CRC will be presented.

Pike, Corey

1991-01-01

403

Payload for the first experimental Indian communication satellite 'APPLE'  

NASA Astrophysics Data System (ADS)

A development history is presented for the Communication Payload of the Ariane Passenger Payload Experiment (APPLE) geosynchronous satellite, which had to meet stringent technological and scheduling requirements. The APPLE spacecraft objectives have allowed the gaining of expertise in communication payload design that is applicable to the Indian National Satellite system. Payload subsystems were developed separately, and the communication transponder was devised after their integration. Attention is given to a quality assurance program, encompassing all aspects of material and component selection, design, fabrication, and testing and evaluation. Design work began in 1977, and an engineering model was completed by the end of 1978.

Lasrado, L.; Ramiah, V.; Shetty, P. N. R.; Pillai, N. S.; Singh, S. K.; Singh, B.; Gupta, R. K.; Garg, V. K.; Saxena, R.; Singh, R.

1983-11-01

404

Advanced Communications Technology Satellite (ACTS): Four-Year System Performance  

NASA Technical Reports Server (NTRS)

The Advanced Communications Technology Satellite (ACTS) was conceived at the National Aeronautics and Space Administration (NASA) in the late 1970's as a follow-on program to ATS and CTS to continue NASA's long history of satellite communications projects. The ACTS project set the stage for the C-band satellites that started the industry, and later the ACTS project established the use of Ku-band for video distribution and direct-to-home broadcasting. ACTS, launched in September 1993 from the space shuttle, created a revolution in satellite system architecture by using digital communications techniques employing key technologies such as a fast hopping multibeam antenna, an on-board baseband processor, a wide-band microwave switch matrix, adaptive rain fade compensation, and the use of 900 MHz transponders operating at Ka-band frequencies. This paper describes the lessons learned in each of the key ACTS technology areas, as well as in the propagation investigations.

Acosta, Roberto J.; Bauer, Robert; Krawczyk, Richard J.; Reinhart, Richard C.; Zernic, Michael J.; Gargione, Frank

1999-01-01

405

Aeronautical mobile satellite service: Air traffic control applications  

NASA Technical Reports Server (NTRS)

Canada's history both in aviation and in satellite communications development spans several decades. The introduction of aeronautical mobile satellite communications will serve our requirements for airspace management in areas not served by line-of-sight radio and radar facilities. The ensuing improvements in air safety and operating efficiency are eagerly awaited by the aviation community.

Sim, Dave

1990-01-01

406

Evaluation of spacecraft technology programs (effects on communication satellite business ventures), volume 1  

NASA Technical Reports Server (NTRS)

Commercial organizations as well as government agencies invest in spacecraft (S/C) technology programs that are aimed at increasing the performance of communications satellites. The value of these programs must be measured in terms of their impacts on the financial performane of the business ventures that may ultimately utilize the communications satellites. An economic evaluation and planning capability was developed and used to assess the impact of NASA on-orbit propulsion and space power programs on typical fixed satellite service (FSS) and direct broadcast service (DBS) communications satellite business ventures. Typical FSS and DBS spin and three-axis stabilized spacecraft were configured in the absence of NASA technology programs. These spacecraft were reconfigured taking into account the anticipated results of NASA specified on-orbit propulsion and space power programs. In general, the NASA technology programs resulted in spacecraft with increased capability. The developed methodology for assessing the value of spacecraft technology programs in terms of their impact on the financial performance of communication satellite business ventures is described. Results of the assessment of NASA specified on-orbit propulsion and space power technology programs are presented for typical FSS and DBS business ventures.

Greenburg, J. S.; Gaelick, C.; Kaplan, M.; Fishman, J.; Hopkins, C.

1985-01-01

407

Future large broadband switched satellite communications networks  

NASA Technical Reports Server (NTRS)

Critical technical, market, and policy issues relevant to future large broadband switched satellite networks are summarized. Our market projections for the period 1980 to 2000 are compared. Clusters of switched satellites, in lieu of large platforms, etc., are shown to have significant advantages. Analysis of an optimum terrestrial network architecture suggests the proper densities of ground stations and that link reliabilities 99.99% may entail less than a 10% cost premium for diversity protection at 20/30 GHz. These analyses suggest that system costs increase as the 0.6 power of traffic. Cost estimates for nominal 20/30 GHz satellite and ground facilities suggest optimum system configurations might employ satellites with 285 beams, multiple TDMA bands each carrying 256 Mbps, and 16 ft ground station antennas. A nominal development program is outlined.

Staelin, D. H.; Harvey, R. R.

1979-01-01

408

GSFC conceptual design study for an inter-satellite Optical Multiple Access communication system  

NASA Technical Reports Server (NTRS)

System and terminal level specifications for an inter-satellite Optical Multiple Access (OMA) communication system are presented, as well as the resulting hardware designs for both OMA relay and OMA user terminals. The OMA relay terminal design uses a mechanical innovation which moves multiple fiber optic pickups in the focal plane, thereby providing simultaneous links with multiple OMA user terminals via a single telescope. Thus, with such a terminal on a relay satellite, multiple access service can be provided with a minimum of impact on the relay satellite.

Fox, Neil; Maynard, Will; Clarke, Ernest; Bruno, Ronald

1991-01-01

409

Multimedia group communications: towards new services  

NASA Astrophysics Data System (ADS)

Interpersonal communication among a group of users employing different media types is becoming more and more widespread in computing and telecommunications. Group communication places a variety of new requirements onto the underlying communications architecture and although many existing protocols and services do offer some limited support for multicast group communication, these new requirements make it difficult to find efficient and comprehensive solutions. The impact of multimedia group communication on the communication system and the way in which existing systems, international standardization bodies and researchers cope with these challenges is the subject of this paper. First the characteristics and requirements of multimedia group applications are discussed and illustrated by examples of existing group applications. Subsequently a survey of the kind of support available in today's communication system is presented. In addition the ongoing discussion about the standardization of group communication within ISO and ITU and the direction these efforts take is briefly summarized. Further, some selected examples of research projects which deal with different communication and protocol related aspects of multimedia group communication are presented which give an indication of the trends in this area.

Mauthe, A.; Hutchison, D.; Coulson, G.; Namuye, S.

1996-09-01

410

Using satellite vibrations to improve performance of free-space satellite laser communication  

NASA Astrophysics Data System (ADS)

In some of the future laser communication satellites, it is plausible to assume that tracking and communication receivers will be using the same array of detector. The reason for such detector dual use is to design simpler and cheaper satellites. Satellites vibrate continually due to operation of their subsystems and environmental sources. The vibrations cause non-uniform spreading of the received energy on the detector array. In view of this, we use the information from the tracking system in order to adapt individually the communication signal gain of each of the detectors in the array. This adaptation of the gains improves communication system performance. It is important to emphasize that the communication performance improvement is achieved by only gain adaptation. Any additional vibrations decrease the tracking and laser pointing system performances, which decrease the return communication performances (two-way communication). A comparison of practical communication systems is presented. The novelty of this research is the utilization of natural satellite vibrations to improve the communication system performance.

Arnon, Shlomi; Rotman, Stanley R.; Kopeika, Norman S.

1998-10-01

411

Communicating data quality through Web Map Services  

NASA Astrophysics Data System (ADS)

The sharing and visualization of environmental data through spatial data infrastructures is becoming increasingly common. However, information about the quality of data is frequently unavailable or presented in an inconsistent fashion. ("Data quality" is a phrase with many possible meanings but here we define it as "fitness for purpose" - therefore different users have different notions of what constitutes a "high quality" dataset.) The GeoViQua project (www.geoviqua.org) is developing means for eliciting, formatting, discovering and visualizing quality information using ISO and Open Geospatial Consortium (OGC) standards. Here we describe one aspect of the innovations of the GeoViQua project. In this presentation, we shall demonstrate new developments in using Web Map Services to communicate data quality at the level of datasets, variables and individual samples. We shall outline a new draft set of conventions (known as "WMS-Q"), which describe a set of rules for using WMS to convey quality information (OGC draft Engineering Report 12-160). We shall demonstrate these conventions through new prototype software, based upon the widely-used ncWMS software, that applies these rules to enable the visualization of uncertainties in raster data such as satellite products and the results of numerical simulations. Many conceptual and practical issues have arisen from these experiments. How can source data be formatted so that a WMS implementation can detect the semantic links between variables (e.g. the links between a mean field and its variance)? The visualization of uncertainty can be a complex task - how can we provide users with the power and flexibility to choose an optimal strategy? How can we maintain compatibility (as far as possible) with existing WMS clients? We explore these questions with reference to existing standards and approaches, including UncertML, NetCDF-U and Styled Layer Descriptors.

Blower, Jon; Roberts, Charles; Griffiths, Guy; Lewis, Jane; Yang, Kevin

2013-04-01

412

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

NASA Astrophysics Data System (ADS)

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

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

413

Management of the fleet satellite communications satellite acquisition for the Naval Postgraduate School  

NASA Astrophysics Data System (ADS)

This thesis discusses the management of the acquisition of the fleet Satellite Communications Satellite (FLTSATCOM) Qualification Model for the Naval Postgraduate School. The preparations, scheduling, and accomplishment of the delivery and the efforts required to establish the FLTSATCO laboratory are discussed. The interaction between the Naval Postgraduate School, various government agencies, and the FLTSATCOM prime contractor necessary to accomplish the project is also described.

Eyler, David E.

1991-06-01

414

Management of the fleet satellite communications satellite acquisition for the Naval Postgraduate School  

Microsoft Academic Search

This thesis discusses the management of the acquisition of the fleet Satellite Communications Satellite (FLTSATCOM) Qualification Model for the Naval Postgraduate School. The preparations, scheduling, and accomplishment of the delivery and the efforts required to establish the FLTSATCO laboratory are discussed. The interaction between the Naval Postgraduate School, various government agencies, and the FLTSATCOM prime contractor necessary to accomplish the

David E. Eyler

1991-01-01

415

Development of a mobile satellite communication unit  

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

416

RF switch positioner for communications satellite network  

NASA Technical Reports Server (NTRS)

The RF switch positioner is a simple, lightweight, redundant positioning mechanism used to reconfigure the antenna beam on the INTELSAT VI satellite. It simultaneously rotates approximately 100 squareax waveguide switches through a full 360 deg. The RF switch positioner has been space qualified and has performed to expectations in conjunction with the feed networks in range testing.

Storaasli, A. G.; Griesser, H. P.; Grant, R. W.

1986-01-01

417

International Organizations to Enable World-Wide Mobile Satellite Services.  

National Technical Information Service (NTIS)

Numbers of systems exist or have been proposed to provide world-wide mobile satellite services (MSS). Developers of these systems have formulated institutional structures they consider most appropriate for profitable delivery of these services. MSS system...

R. L. Anglin

1993-01-01

418

Commercial optical inter-satellite communication at high data rates  

NASA Astrophysics Data System (ADS)

Laser communication terminals with data rates far above 1 Gbps have been in operation in orbit since January 2008, and the links established between two low Earth orbit (LEO) satellites have demonstrated error-free communication. Bit error rates better than 10-11 have been achieved without data encoding. Signal acquisition can be reproducibly achieved within a few seconds. After adaptation to larger link separation distances these laser communication terminals will be used in the low earth orbit-geosynchronous satellite (LEO-GEO) link of European data relay satellite (EDRS), the GEO European data relay system. LEO-to-ground and ground-to-LEO links have examined the impact of the atmosphere on such optical links. In the future, high data rate GEO-to-ground links will require ground stations equipped with adaptive optics, which are currently under development.

Gregory, Mark; Heine, Frank; Kämpfner, Hartmut; Lange, Robert; Lutzer, Michael; Meyer, Rolf

2012-03-01

419

75 FR 5513 - Determination of Rates and Terms for Preexisting Subscription Services and Satellite Digital...  

Federal Register 2010, 2011, 2012, 2013

...Preexisting Subscription Services and Satellite Digital Audio Radio Services AGENCY...governing the rates for the preexisting satellite digital audio radio services' use of...period 2007 through 2012 for preexisting satellite digital audio radio services...

2010-02-03

420

A multifrequency offset reflector antenna for regional satellite communications  

Microsoft Academic Search

The paper describes the conceptual design of a shaped-beam satellite antenna subsystem which fulfils the requirement for simultaneous operation at three discrete frequency bands. The antenna consists of a single elliptically-apertured offset paraboloidal reflector with a three-element array of multifrequency feedhorns multimoded at the highest frequency. The overall mechanical design of the antenna is compatible with the European communication satellite

B. Claydon; A. W. Rudge; J. Cowan

1978-01-01

421

An adaptive array antenna for mobile satellite communications  

NASA Technical Reports Server (NTRS)

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

Milne, Robert

1990-01-01

422

EHF for Satellite Communications: The New Broadband Frontier  

Microsoft Academic Search

The exploitation of extremely high-frequency (EHF) bands (30-300 GHz) for broadband transmission over satellite links is currently a hot research topic. In particular, the Q-V band (30-50 GHz) and W-band (75-110 GHz) seem to offer very promising perspectives. This paper aims at presenting an overview of the current status of research and technology in EHF satellite communications and taking a

Ernestina Cianca; Tommaso Rossi; Asher Yahalom; Yosef Pinhasi; John Farserotu; Claudio Sacchi

2011-01-01

423

Broadband and scalable mobile satellite communication system for future access networks  

NASA Astrophysics Data System (ADS)

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

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

2005-07-01

424

The 18/30 GHz Fixed Communications System Service Demand Assessment. Volume 1: Executive Summary.  

National Technical Information Service (NTIS)

The total demand for voice, video, and data communications services, and satellite transmission services at the 4/6 GHz, 12/14 GHz, and 18/30 GHz frequencies is discussed. Major study objectives, overall methodology, results, and general observations abou...

T. Gabriszeski P. Reiner J. Rogers W. Terbo

1979-01-01

425

Teletraffic modeling for personal communications services  

Microsoft Academic Search

This article presents a realistic teletraffic modeling framework for personal communications services. The framework captures complex human behaviors and has been validated through analysis of actual call and mobility data. Using the proposed framework, a large-scale simulation was performed on a model of the San Francisco Bay area. Simulation results showing the performance of IS-41 are presented

Derek Lam; Donald C. Cox; Jennifer Widom

1997-01-01

426

Programmable group communication services over IP multicast  

Microsoft Academic Search

Advances in high speed routing and switching devices in have made it possible to facilitate both new network services such as group communication, and to increase the level of router programmability. Programmability is considered as a feature not only allowing to better meet applications requirements (user viewpoint) but also to optimise network resources (provider viewpoint). We show how multicast-one of

Michael Smirnov; Henning Sanneck; Dorota Witaszek

2000-01-01

427

Development of a mobile satellite communication unit  

Microsoft Academic Search

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

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

1988-01-01

428

Local oscillator selection for digital satellite communications  

NASA Astrophysics Data System (ADS)

The paper presents a comparative study of different local oscillator (LO) designs and their suitability for digital communications. Based on the system budget for performance degradation due to carrier phase noise, a specification for the LO phase noise is derived. Consideration is given to the following types of LO subsystems: mechanical cavity, VTO-PLO, DRO-PLO, and multiplier chain.

Kumar, Surinder

1988-07-01

429

Design and evaluation of control systems for large communications satellites  

NASA Technical Reports Server (NTRS)

Control techniques for future large flexible spacecraft are developed. Control design and analysis are supported by a comprehensive CAD system. The proposed operational mobile communications satellite (OMSAT) featuring a 44 m offset fed antenna is used as target application. Requirements for satellite attitude control and communications beam pointing are defined. The following control methods are applied to the system: standard linear optimal regulator (LOR) with Luenberger observer, LOR/observer with selective spill-over suppression, frequency shaped LOR, LOR with closed-loop order reduction by cost decoupling, and robust servomechanism.

Steiber, M. E.

1985-01-01

430

Experimental millimeter-wave personal satellite communications system  

NASA Technical Reports Server (NTRS)

Communications Research Laboratory (CRL) has investigated an advanced millimeter (mm)-wave satellite communications system for personal use. Experiments in mm-wave personal satellite communication are to be conducted for 3 years using Japan's Engineering Test Satellite VI (ETS-VI). This paper describes an experimental mm-wave (43/38 GHz) personal satellite communication system, including an onboard transponder and an earth terminal. The on-board transponder is almost completed, and the ground experiment system is still in the design stage. The transponder employs advanced mm-wave solid state technology. It uses 38 GHz high power solid state amplifiers to accelerate the development of mm-wave solid state devices which are indispensable to personal earth terminals. The transponder consists of a 43 GHz receiver with a built-in low noise amplifier, an IF filter section with very narrow bandwidth to improve the carrier-to-noise power ratio of the weak personal communication signal, and two high power amplifiers using newly developed high power Gallium Arsenide (GaAs) metal-semiconductor field effect transistors (MESFETs).

Suzuki, Yoshiaki; Kimura, Shigeru; Shimada, Masaaki; Tanaka, Masato; Takahashi, Yasuhiro

1991-01-01

431

Advanced Communication Technology Satellite (ACTS) multibeam antenna technology verification experiments  

NASA Technical Reports Server (NTRS)

The Advanced Communication Technology Satellite (ACTS) is a key to reaching NASA's goal of developing high-risk, advanced communications technology using multiple frequency bands to support the nation's future communication needs. Using the multiple, dynamic hopping spot beams, and advanced on board switching and processing systems, ACTS will open a new era in communications satellite technology. One of the key technologies to be validated as part of the ACTS program is the multibeam antenna with rapidly reconfigurable hopping and fixed spot beam to serve users equipped with small-aperature terminals within the coverage areas. The proposed antenna technology experiments are designed to evaluate in-orbit ACTS multibeam antenna performance (radiation pattern, gain, cross pol levels, etc.).

Acosta, Roberto J.; Larko, Jeffrey M.; Lagin, Alan R.

1992-01-01

432

The Army's Use of the Advanced Communications Technology Satellite  

NASA Technical Reports Server (NTRS)

Tactical operations require military commanders to be mobile and have a high level of independence in their actions. Communications capabilities providing intelligence and command orders in these tactical situations have been limited to simple voice communications or low-rate narrow bandwidth communications because of the need for immediate reliable connectivity. The Advanced Communications Technology Satellite (ACTS) has brought an improved communications tool to the tactical commander giving the ability to gain access to a global communications system using high data rates and wide bandwidths. The Army has successfully tested this new capability of bandwidth-on-demand and high data rates for commanders in real-world conditions during Operation UPHOLD DEMOCRACY in Haiti during the fall and winter of 1994. This paper examines ACTS use by field commanders and details the success of the ACTS system in support of a wide variety of field condition command functions.

Ilse, Kenneth

1996-01-01

433

Recent Korean R&D in Satellite Communications  

Microsoft Academic Search

The R&D in satellite communications in Korea has been driven mainly by KCC (Korea Communications Commission) but in a small scale compared to Korea space development program organized by MEST (Ministry of Education, Science and Technology). Public and civilian satcom sector R&D has been led mainly by ETRI with small\\/medium companies contrary to rare investment in private sector while military

Ho-Jin Lee; Jae Moung Kim; Byung-Seub Lee; Han Lee; Jang-Soo Ryoo

2009-01-01

434

Modulation/demodulation techniques for satellite communications. Part 1: Background  

NASA Technical Reports Server (NTRS)

Basic characteristics of digital data transmission systems described include the physical communication links, the notion of bandwidth, FCC regulations, and performance measurements such as bit rates, bit error probabilities, throughputs, and delays. The error probability performance and spectral characteristics of various modulation/demodulation techniques commonly used or proposed for use in radio and satellite communication links are summarized. Forward error correction with block or convolutional codes is also discussed along with the important coding parameter, channel cutoff rate.

Omura, J. K.; Simon, M. K.

1981-01-01

435

Individual Global Navigation Satellite Systems in the Space Service Volume  

NASA Technical Reports Server (NTRS)

The use of individual Global Navigation Satellite Services (GPS, GLONASS, Galileo, and Beidou/COMPASS) for the position, navigation, and timing in the Space Service Volume at altitudes of 300 km, 3000 km, 8000 km, 15000 km, 25000 km, 36500km and 70000 km is examined and the percent availability of at least one and at least four satellites is presented.

Force, Dale A.

2013-01-01

436

Improving Library Services to Satellite Campuses: The Case of the University of Lethbridge  

ERIC Educational Resources Information Center

A survey was done of instructors at two satellite campuses located at a distance from the main campus of the University of Lethbridge in order to ascertain both utilization and awareness of library resources and services. Results were enlightening, indicating that lack of awareness and communication is one of the biggest obstacles for these…

Eva, Nicole C.

2012-01-01

437

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

NASA Astrophysics Data System (ADS)

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

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

2002-01-01

438

Performance Limitations of a Free-Space Optical Communication Satellite Network Owing to Vibrations: Heterodyne Detection  

Microsoft Academic Search

Free-space optical communication between satellites in a distributed network can permit high data rates of communication between different places on Earth. To establish optical communication between any two satellites requires that the line of sight of their optics be aligned during the entire communication time. Because of the large distance between the satellites and the alignment accuracy required, the pointing

Shlomi Arnon; Stanley R. Rotman; Norman S. Kopeika

1998-01-01

439

Achieving QoS for TCP Traffic in Satellite Networks with Differentiated Services  

NASA Technical Reports Server (NTRS)

Satellite networks play an indispensable role in providing global Internet access and electronic connectivity. To achieve such a global communications, provisioning of quality of service (QoS) within the advanced satellite systems is the main requirement. One of the key mechanisms of implementing the quality of service is traffic management. Traffic management becomes a crucial factor in the case of satellite network because of the limited availability of their resources. Currently, Internet Protocol (IP) only has minimal traffic management capabilities and provides best effort services. In this paper, we presented a broadband satellite network QoS model and simulated performance results. In particular, we discussed the TCP flow aggregates performance for their good behavior in the presence of competing UDP flow aggregates in the same assured forwarding. We identified several factors that affect the performance in the mixed environments and quantified their effects using a full factorial design of experiment methodology.

Durresi, Arjan; Kota, Sastri; Goyal, Mukul; Jain, Raj; Bharani, Venkata

2001-01-01

440

The performance limitations of free space optical communication satellite networks due to vibrations-analogs case  

Microsoft Academic Search

Free space optical communication between satellites networked together can make possible high speed communication between different places on Earth. In this work we derive mathematical models of signal, noise, and approximate bit-error-rates of optical communication satellite networks as functions of the system parameters. The optical inter-satellite network model considered includes transmitter satellite, repeater satellites, and receiver satellite all networked together.

S. Arnon; N. S. Kopeika

1996-01-01

441

The performance limitations of free space optical communication satellite networks due to vibrations-analog case  

Microsoft Academic Search

Free space optical communication between satellites networked together can make possible high speed communication between different places on Earth. We derive mathematical models of signal, noise, and approximate bit-error-rates of optical communication satellite networks as functions of the system parameters. The optical inter-satellite network model considered includes transmitter satellite, repeater satellites, and receiver satellite all networked together. From the analysis

S. Arnon; N. S. Kopeika

1996-01-01

442

Space station automation study-satellite servicing, volume 2  

NASA Technical Reports Server (NTRS)

Technology requirements for automated satellite servicing operations aboard the NASA space station were studied. The three major tasks addressed: (1) servicing requirements (satellite and space station elements) and the role of automation; (2) assessment of automation technology; and (3) conceptual design of servicing facilities on the space station. It is found that many servicing functions cloud benefit from automation support; and the certain research and development activities on automation technologies for servicing should start as soon as possible. Also, some advanced automation developments for orbital servicing could be effectively applied to U.S. industrial ground based operations.

Meissinger, H. F.

1984-01-01

443

Pilot program and operational users of CS-2 communication satellite in Ka-band  

NASA Astrophysics Data System (ADS)

The Japanese communication satellites CS-2a and CS-2b were launched in 1983. Each satellite has six Ka-band transponders and two C-band transponders. Operational users of public or governmental organizations are using CS-2s. In addition to these operational users, CS-2 Pilot Program participants are using CS-2s for preoperational experiment in Ka-band. More than 50 earth stations of Ka-band are utilizing CS-2s in operational use. Configuration of the operational use are back-up link to their terrestrial lines in an emergency or tentative transmission link in case of disaster or event. Satellite business communication services using small antenna started recently. Thirty-two earth stations with 1 to 5-m antennas are used in the Pilot Program. Some results of experiments in the Pilot Program were obtained.

Hashimoto, K.; Yamamoto, M.; Iguchi, M.; Yamazaki, I.

1986-10-01

444

Pilot program and operational users of CS-2 communication satellite in Ka-band  

NASA Astrophysics Data System (ADS)

Communication satellites of Japan, CS-2a and CS-2b were launched in 1983. Each satellite has 6 Ka-band transponders and 2 C-band transponders. Operational users of public or governmental organizations are using CS-2's. In addition to these operational users, CS-2 Pilot Program participants are using CS-2's for preoperational experiment in Ka-band. More than 50 earth stations of Ka-band are utilizing CS-2's in operational use. Configuration of the operational use are back-up link to their terrestrial lines in an emergency or tentative transmission link in case of disaster or event. Satellite business communication services using small antenna started recently. 32 earth stations of 1 to 5 meter antenna are used in the Pilot Program. Some results of experiments in Pilot Program were obtained.

Hashimoto, Kazuhiko; Yamamoto, Minoru; Iguchi, Masaaki; Yamazaki, Ichiro

445

Communications Satellites: A New Channel for International Communications, A New Source of International Tension.  

ERIC Educational Resources Information Center

Communications satellites could be the subject of bitter and potentially dangerous international controversy. They threaten to upset the comfortable monopoly of internal national communications systems which have enrolled national governments to screen intrusions of unwanted information or ideas. The United Nations Working Committee on Direct…

Mickelson, Sig

446

Adaptive satellite communications under computer control  

NASA Astrophysics Data System (ADS)

The influence of increased computing power through microprocessors is seen as influencing design in two ways. The first is that it alters the concepts upon which payloads are based; the second is that it makes possible an extension of technology to cope with these demands. Microprocessor technology not only influences equipment design, it also affects the nature of the communication information itself by increasing data traffic and making digital transmission preferable. The influences of the technology in payloads is discussed here by using a particular example in which high capacity data transmission is foreseen.

Gregory, D. N.; Martin, A. G.

1983-10-01

447

Within compound, looking southeast, Satellite Communications Terminal Building (Building 5771) ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Within compound, looking southeast, Satellite Communications Terminal Building (Building 5771) to left, Gate House (Building 5764) to right of center - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

448

An overview of the Communications Technology Satellite (CTS) project  

NASA Technical Reports Server (NTRS)

The Communications Technology Satellite (CTS) project is reviewed. A technical description of the CTS spacecraft and its cognate hardware and operations is included. A historical treatise of the CTS project is provided. Also presented is an overview of the CTS experiments and demonstrations conducted during the course of the project.

Rapp, W.; Ogden, D.; Wright, D.

1982-01-01

449

Multiquantum well beam-steering device for laser satellite communication  

Microsoft Academic Search

With the increasing interest in laser satellite communications, new methods are sought to solve the existing problems of accurate and rapid laser beam deflection. Current solutions in the form of galvanometers or piezo fast steering mirrors with one or two degrees of freedom are bulky, power-consuming and slow. The Multi-Quantum Well (MQW) is a semiconductor device with unique potential to

Roee Lahat; Itamar Levy; Shlomi Arnon

2002-01-01

450

A reduced complexity digital multicarrier demodulator for satellite communication systems  

Microsoft Academic Search

The design of a completely digital multicarrier demodulator (MCD) for application in advanced satellite communication systems is presented. The MCD represents a complete solution for a processing system interfacing FDMA and TDM links. Its design is in particular aimed at possible implementation by means of custom VLSI digital circuits. The proposed MCD has two parts: the demultiplexer and the coherent

E. del Re; R. Fantacci

1988-01-01

451

Hardware Realization of Modified CIC Filter for Satellite Communication  

Microsoft Academic Search

Cascaded Integrated Comb (CIC) filters are mainly used as low pass filter in rate converter module in a multi rate signal processing based systems. Hardware implementation of CIC filter is very efficient as it does not require any multiplier and uses very less memory. The paper presents the FPGA implementation of modified Cascaded Integrated Comb (CIC) filter for satellite communication

Satish Sharma; Sunil Kulkarni; M. Vanitha; P. Lakshminarsimhan

2010-01-01

452

New Opportunities with the Advanced Communications Technology Satellite (ACTS)  

NASA Technical Reports Server (NTRS)

Various issues associated with the Advanced Communications Technology Satellite (ACTS) are presented in viewgraph form. Specific topics include: 1) ACTS program review; 2) Spot beam locations; 3) Key ACTS technologies; 4) ACTS accomplishments; 5) Experiments operations; 6) Inclined orbit opportunity, mission and impact; 7) Modifications summary; 8) Experiment opportunity, categories, processes; and 9) Recent and ongoing activity.

Bauer, Robert

1998-01-01

453

An OFDM system Optimization for Satellite Communication in Ka Band  

Microsoft Academic Search

An OFDM system optimization for satellite communication in Ka band is estimated in terms of the Shannon theory. The analysis covers a novel closed-form expression for the optimal subcarriers, with respect to the maximization of the achieved spectral efficiency, expressed in terms of the theoretically Shannon channel capacity available to each system's user.

Da Xin-yu; Zhu Hai-feng

2008-01-01

454

Processing voice and data in mobile satellite communications  

Microsoft Academic Search

An on-line self adaptive scheme is required to overcome delays in voice transmission to mobile terminals in satellite communications systems. A method to combat specular multipath and increase signal processing capability for voice and data transmission is described, and system performance evaluated. A signal model is developed to account for transmission parameters, with attention to Gaussian variables. Finally, an optimum

T. P. McGarty; K. S. Schneider

1977-01-01

455

Multiple access techniques for low data rate satellite communication systems  

Microsoft Academic Search

There are many applications of low data rate satellite communications that range from data collection to position surveillance. A common characteristic of all of these systems is that a low cost design is essential and the maximum throughput should be achieved. In this paper we discuss a set of multiple access techniques that can be employed for such applications. We

T. P. McGarty; K. J. Singh

1977-01-01

456

Reliable satellite communications for a specular multipath channel  

Microsoft Academic Search

In many mobile satellite communication systems specular multipath exists and acts as a distortion to the transmitted message stream. In most cases there is a singular specular return which can be characterized by a delay and reflection coefficient. If this return is viewed as intersymbol interference on the channel, then it is possible to consider the resulting channel as modeled

K. S. Schneider; T. P. McGarty

1978-01-01

457

Reliable Satellite Communications for a Specular Multipath Channel  

Microsoft Academic Search

In many mobile satellite communication systems specular multipath exists and acts as a distortion to the transmitted message stream. In most cases there is a singular specular return which can be characterized by a delay and reflection coefficient. If this return is viewed as intersymbol interference on the channel, then it is possible to consider the resulting channel as modeled

K. Schneider; T. McGarty

1978-01-01

458

4-element printed array antenna for land mobile satellite communications  

Microsoft Academic Search

A high-efficiency four-element printed array antenna composed of one-point feed crossed-dipole printed elements with a reflector has been developed. The authors describe the design techniques of the antenna for INMARSAT mobile satellite communication system use and present experimental results

Y. Kazama; Sigeru MATSUMOTO; Hajime SHIROTORI; Tamotsu SUDA; Kenzo KASAMAKI

1992-01-01

459

A study and experiment plan for digital mobile communication via satellite  

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

460

Personal communications services: Improving theater deployable communications for the 21st century  

Microsoft Academic Search

Personal Communications Services (PCS) may be the key ingredient for vastly improved military communications capabilities at the turn of the century. The Federal Communications Commission (FCC) defines PCS as a family of mobile or portable radio communications services which could provide services to individuals and businesses and be integrated with a variety of competing networks ... the primary focus of

Ronald C. Cournoyer Jr.

1994-01-01

461

United States societal experiments via the Communications Technology Satellite. [antenna coverage  

NASA Technical Reports Server (NTRS)

The Communications Technology Satellite (CTS) is a cooperative experimental program of the United States and Canadian governments. The CTS uses a high-power transponder at the frequencies of 14/12 GHz for two-way television and voice communication. The United States and Canada have agreed to share equally in the use of CTS. The U.S. program includes a variety of societal experiments. The g