TELE-X - a Satellite System for TV and Data Communication ...

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TELE-X-a Satellite System for TV and Data Communication Sievert Bergman, Krister Ljungberg and Lars-Gunnar Sundin TELE-X is the designation of a complete telecommunication system covering the Nordic countries. The system includes a satellite with different transmission channels for direct broadcasting of television and for data and video transmission. The authors describe the characteristics of the system, some of which are unique, different types of earth stations, the traffic control, the satellite payload and the implementation of the whole project. UDC 621.397:621.371.36 681.3:621 371.36 The initial studies for TELE-X were started in 1980, and two years later the Swedish Parliament adopted a budget for the whole project of 1250 M Swedish kronor. Later on an agreement was concluded which led to Norway's participation in the project, corresponding to 15% of the project cost. Finally, in the autumn of 1983 Finland decided to participate to a value of approximately 4% of the project cost. The Swedish contribution is thus 81 % of the final sum. The system requirements have been prepared jointly by the Swedish Space Corporation, the Telecommunications Administrations (initially only the Swedish) and the industry. In the middle of 1983, when the Nordic basis for the project had been extended, a Nordic telecommunication satellite consortium, NOTELSAT, was formed. It is owned jointly by the participating countries, and is responsible for both procurement and operation. NOTELSAT has delegated the procurement and project management of TELE- X to the Swedish Space Corporation but intends to take over the operation of the system after launch. The satellite has the same type of platform as that now being developed for the French and German direct broadcast satellites, but it has a different payload since TELE-X also includes data and video communication. The main supplier is the French company Aerospatiale, and Ericsson Radio Systems AB is responsible for the payload The ground segment will be delivered by Ericsson Radio Systems in collaboration with Norwegian and Finnish industry Facilities System TELE-X is intended for data and video communication between small earth stations as well as for direct broadcasting of television. Within the Scandinavian coverage area the power flux density of the television transmission is sufficient for receivers equipped with 90cm parabolic antennas. Such home receivers are expected to be generally available in the market by the time the TELE-X satellite is launched, and are not included in the development program for TELE-X As regards the data and video service the aim is to supplement the Nordic telecommunications networks with wideband facilities, which would otherwise have been impossible to realize for reasons of time and cost. Fig. 1 The coverage area for the data and video service 1.8 m antenna 2.5 m antenna •
The unique facility of a satellite system in providing immediate coverage of the whole service area is thus of paramount importance. The applications now considered for these wideband data services are: Business services - private business networks - electronic mail - high-speed telefacsimile Video conferencing Communication between computers - high speed transmission of data bases - fault tracing in computers - sharing of computer resources and standby computer facilities - electronic document retrieval and delivery Distribution of pictures, for example from satellites for remote analysis of earth resources Remote printing of newspapers. In addition to these business data services there are also interesting video and broadcasting possibilities: Video services - tele education - tele medicine - televised events (transmission to special video theatres) - video distribution, for example within a hotel chain - security television - distribution of pay television to cable television networks TV and radio program contribution - from permanent transmitters - from mobile transmitters (outside broadcasting). The business data services can be combined in one and the same business station with the standardized transmission capacities 2 Mbit/s and n x 64 kbit/s. The 2Mbit/s channel can then be shared in time between data transmission and video conferencing, while the 64kbit/s channels can be used simultaneously and independently of each other for, for example, high-speed facsimile, data or speech. Choice of systems and networks The TELE-X data and video systems must be able to work with small and simple earth stations. This makes it possible to place the station with the user, unlike present-day satellite systems, which require large earth stations and hence a great concentration of traffic in order to warrant a station. In certain areas there may be good reasons for connecting limited Local Area Networks (LAN) to an earth station, in order to provide direct communication within the LAN without having to use the satellite. This releases satellite capacity for long-distance communication. This is illustrated in fig. 2, where an industrial Fig. 2 An example showing the business communication facilities
Page 1: ERICSSON REVIEW Integrated Maintena
Page 5: ERICSSON REVIEW Number 1 1983 Volum
Page 9 and 10: Technical data for a station Antenn
Page 11 and 12: Technical data for the feeder link
Page 13 and 14: 9 Fig. 7 Mixer and preamplifier The
Page 15 and 16: MATS ENEBORG Fibre Optics and Line
Page 17 and 18: 13 Fig. 6 The structure of system Z
Page 19 and 20: 15 Fig. 9 Part of the junction netw
Page 21 and 22: Fig. 11 Part of an urban and trunk
Page 23 and 24: 19 MATS ENEBORG BJORN JOHANSEN Depa
Page 25 and 26: Fig. 6 An example of a printout of
Page 27 and 28: Technical data for ZAN 101 Maximum
Page 29 and 30: Fig. 14 The Transmission maintenanc
Page 31 and 32: 27 BJORN LENGQUIST PER AKE WIBERG E
Page 33 and 34: 29 Supervision of the digital inter
Page 35 and 36: 31 ules can be used to successively
Page 37 and 38: BENGTJANSSON KENT JOHANSSON TOMMY O
Page 39 and 40: 35 The control individuals are divi
Page 41 and 42: 37 Fig. 10 LPB 110 used in an AXE 1
Page 43 and 44: 39 BENGT LAGERSTEDT Public Telecomm
Page 45 and 46: 41 Fig. 6 With multiplexer ZAH 1.5/
Page 47 and 48: Fig. 10 In this example of the use
Page 49 and 50: 45 HARALD BRANDT ALEKSANDER MARLEVI
Page 51 and 52: 47 Fig. 5 Stored program controlled
Page 53 and 54: 49 quency jumps and no transmission
Page 55 and 56: Hotel Communication System Robert D
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53 Fig. 3 The answer telephones at
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55 The capacity of the hotel PABX i
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57 Fig. 7 The hotel computer, Erics
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Hardening of Telecommunication Netw
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Fig. 3 The electrical and magnetic
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63 Rise Duration time Time Fig. 7 D
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65 Component Microwave diodes Digit
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67 electrical safety regulations, a
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ERICSSON ISSN 0014-0171 Telefonakti
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TELE-X - a Satellite System for TV and Data Communication ...

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