Site: EUTELSAT Headquarters
Tour Maine, Montparnasse
33 Avenue Du Maine
75775 Paris Cedex 15
Date Visited: June 25, 1992
Report Author: W. Brandon
Dr. Mike Nicolaides
Herbert D. Cohen
EUTELSAT is a consortium originally formed for satellite telephony. Due to political changes in Europe, EUTELSAT is currently experiencing rapid growth in membership, with Czechoslovakia having just become a full member, Armenia and Hungary in the approval process and Croatia having just applied for membership. To be a member, it is required that a country be sovereign, European, and a member of ITU. PTTs are signatories and determine services or operational use of satellites. Ownership (investment) is proportional to use. Currently, France, the UK, Spain, and Germany are all about equal in investment at about 18%. Italy's share stands at 9%, and other countries have smaller percentages. While created for telephony, television distribution has become its major service, with 23 channels (transponders) currently used to distribute television in ten languages.
EUTELSAT has acquired and operates on behalf of its signatories a communications satellite system that by 1993 will consist of seven geostationary satellites in seven orbit positions (1o, 7o, 10 degrees, 13 degrees, 16 degrees, 21.5 degrees, 36 degrees East). These satellites support telephony, business services, television and radio distribution, and mobile communications. EUTELSAT is promoting EUROPESAT for broadcasting, which requires a special agreement among signatories; a final decision is expected this year (1992).
EUTELSAT collaborates with and relies on ESA as its primary research and development agent to provide "progressive technology." The staff at EUTELSAT performs some studies and manages others contracted elsewhere.
EUTELSAT is experiencing rapid growth in the types of services it provides. Signatories to EUTELSAT are also signatories to Inmarsat and INTELSAT. Consequently, EUTELSAT has the same potential roles as these organizations, except on a regional basis, in providing all types of satellite communications services.
This record is organized by services with emphasis on research and development and new directions.
Although there are extensive fiber optic networks in Europe, satellite communications enjoys four distinct advantages:
Generally, each country has more than one earth station (e.g., Italy has earth stations at Fuchino and Lario in the INTELSAT system).
A TDMA system similar to that used by INTELSAT is used for country to country telephony. The TDMA frame is two msec in duration. Time slot assignments are made over eight transponders, with transmitters hopping between transponders, an innovative feature. TDMA is by reservation, with a new time- frequency plan introduced about twice per year. No development is contemplated at this time towards a more responsive demand assignment (DAMA) system. Some networks are used to absorb peak demands that exceed land line capacity. Some sixty stations operating at 60 Mbits/sec are used in this way.
An intermediate step towards personal communications services (PCS) is being considered, providing voice, data and facsimile service into a briefcase terminal. It would operate at 4.8 kbits/sec and 16 kbits/sec through a 2 m hub. Using a 2.4 m antenna, 64 kbits/sec links "direct" (user to user without a hub) are possible. (Direct user-to-user links are said to form an "open network".)
EUTELTRACS. Introduced in January, 1991, EUTELTRACS is a system for tracking and communications services for mobile applications, primarily trucks. (It is similar to the U.S. OmniTracs operational system of Qualcomm, Inc., and is the result of a QualComm-ALCATEL partnership.) EUTELTRACS provides 300 m position accuracy to a potential 45,000 mobile users in Europe. The terminal antenna tracks in azimuth and provides 19 dB gain (receive).
Though quite new, EUTELSAT is considering the "evolution" of EUTELTRACS to provide "embedded localization." This is considered a mandatory service required by the EUTELSAT charter and will be termed the European Mobile System (EMS). As the initial step in this evolution, ESA will provide a piggyback L-band payload for ITALSAT F2, to be launched in 1994.
Currently, television is distributed (for rebroadcast or cable connection) using the FSS. Signatories (PTTs) determine use of the transponders. The European Broadcasting Union (EBU) is a special customer. EUTELSAT now provides four transponders for EBU use and plans two more. This is being done in the FSS without approval of the EUTELSAT Board of Governors.
EUROPESAT. The Board has authorized EUTELSAT to act as acquisition agent for a direct broadcast satellite system. EUTELSAT is promoting EUROPESAT for TV broadcasting. As noted above, the operational system is now in the approval process, with a decision expected soon. A "gapsat" will be procured to initiate service within 24 months while the operational EUROPESAT is being developed. The "gapsat" or pre-EUROPESAT will use 33 MHz transponders.
Ultimately, three EUROPESAT satellites will be placed at one location (co-located). Satellite antennas will provide coverages that match the geographic regions corresponding to languages. To obtain enough spectrum, EUTELSAT is making use of a World Administrative Radio Conference 1977 (WARC '77) provision allocating five channels to each country. Thus eight countries provide a total of 40 channels which may be redistributed unevenly per country upon authorization of the EUTELSAT Board. A transponder EIRP of 55 dBw for primary coverage areas is planned, broadcasting to an 80 to 90 cm receive antenna. For digital HDTV, a 108 MHz bandwidth transponder is being considered. Alcatel and EF Data 8-phase PSK modems that support 140 to 155 Mbits/sec operation may be used.
The EUROPESAT program has been ongoing since 1985. Major program milestones are given in Table EUTELSAT.1.
Major EUROPESAT Program Milestones
All four spacecraft (including gapsat) are to be co-located at 19oW. The final configuration will have three satellites of 14 channels each, totalling 40 operational and two spare channels. Thus each of the ten participating countries will use four channels compared to five allocated under the WARC 1977. EIRP varies from 55 dBw minimum to 60 dBw over part of Italy and 57 dBw onto France. Gapsat will have 12 channels (instead of l4) and may be launched as early as 1993.
EUREKA 95. EUREKA 95 is a large pan-European program to carry out research and development, future system evaluation, pilot production of equipment for HDTV service (for major events), and to prepare for a market introduction by 1995 of satellite transmission of HD-MAC, "studio to home." (The goal of satellite delivery relates EUREKA to DBS.) The project also embraces cable delivery of HD-MAC, development and maintenance of specifications, transmission test and evaluation. EUTELSAT participates in and will use the results of work produced by the International Telecommunications Union's (ITU's) Consultative Committee on International Radio (CCIR) Study Groups (SGs) 4 (FSS) and 10 (TV) appropriate to satellite transmission.
The RACE Project. The Research in Advanced Communications Experiment/Europe project is a broad umbrella R&D program that is customer-premises equipment oriented and not exclusively satellite related. The objectives of RACE include advancing transmission techniques and applications, improving ground segment technology, and compatibility of satellite and terrestrial transmission systems. RACE includes at least three efforts related to satellite communications -- Flash TV, UNOM and Catalyst.
FLASH TV. The Flexible Advanced Satellite System for High Quality TV (FLASH TV) R&D activity is sponsored by the Commission of European Communities. It is aimed at broadcast of digital HDTV for redistribution ("contribution links") rather than direct broadcast. One application might entail distribution to theaters for projection of a cinema. Flash TV will use transmission rates less than 70 Mbits/sec whereas HD-MAC will be transmitted at 140 Mbits/sec.
HDTV demands high data rates, in turn requiring larger receive stations and concern for link margins, interference and propagation. The tradeoff of data rate versus video quality and the use of coding (compression) is being investigated by many entities around the world. In FLASH TV, a novel approach is being investigated. The transmission data rate will be adapted to the available margin by a low rate feedback link from the receiver (in essence, bit error rate monitoring at the receiver). The scheme also envisions use of video compression, transmission probably at rates of 34 to 70 Mbits/sec, and reception with antennas of less than 4 m diameter at Ku-band. It is also thought that the flexible bit rate technology could be transferred to Ka-band (30/20 GHz), should that become desirable. The flexible rates will also be interfaced to terrestrial networks. A graceful degradation characteristic is expected in video quality. The original video input is considered to have high and low priority units (components). In case of node congestion, the asynchronous transfer mode (ATM) network can drop the low priority video data without resulting in unacceptable video quality.
The video in this scheme is not called HDTV or HD-MAC but is a high quality standard. The difference may be better understood by comparing the encoding schemes. The HD-MAC standard is 1,250 lines, refreshed at 50 Hz, with a 16:9 picture aspect ratio. The same camera would be used for FLASH TV. The camera output, when converted to a digital bit stream, is about 1.6 Gbits/sec. A conventional approach would take this output and apply discrete cosine transforms to reduce the data rate. In FLASH TV, other processing is performed with the objective of reducing the data rate to 70 Mbits/sec. Using a 36 MHz transponder, and 74 dBw uplink EIRP, reception of high quality is anticipated using a 2 m to 4 m antenna, with a target of 3 m, using an EF data modem. This system is expected to deliver a professional quality picture appropriate for consumer display by 1994. By comparison, it is expected that analog HD-MAC can be received from EUROPESAT using an 80 cm antenna. However, due to wide bandwidth and high EIRP requirements, there will be relatively few DBS HD-MAC TV channels. The FLASH TV concept is compatible with a 36 MHz transponder and terrestrial transmission, and thus would have much broader applicability in business, government, news gathering and entertainment.
UNOM. The UNOM project is led by Matra Ericsson Telecomm (MET). This activity is concerned with satellite transmission only within the broader context of transmission and networking technology. Integration of satellite and terrestrial transmission is one objective. Applications include local area network to wide area network (LAN/WAN) interconnection; interconnection of ATM "islands" or "data islands" at high speed; ATM gateway connectivity for mapping of ATM cells; and interconnection and conversion of ETHERNET computer networks. The technology involved includes concatenated codes, satellite access protocols, and link data rates of 2 Mbits/sec to 8 Mbits/sec. Satellite transmission will be limited to TCP.
Catalyst. The Catalyst project is led by ATES. Satellite access protocols are a major focus. Development is aimed at adaptation or accommodation of the round trip propagation time delay encountered with satellites. Objectives include integration of satellites and broadband networks, provision of network management, improvement of link quality, incorporation of a multi-point (broadcast or multi-cast) capability, and development of recommendations for adjustment of the CCIR/CCITT standards with regard to accommodating satellite propagation delay. Catalyst will bring together certain technologies for high speed networks as shown in Table EUTELSAT.2.
Technologies for High Speed Networks
Certain activities were described that may or may not fall within the RACE project. These are in preliminary stages but indicate the broad dimensions of research interests.
A joint ESA/EUTELSAT study on OBP is underway. It appears directed at simple implementation of circuit switching. System designs involving 12 spot beams and two European theater beams are being considered. A 2 Mbits/sec uplink to 33 Mbits/sec TDMA downlink scheme is also under study. For implementing mesh VSAT networks, rates up to 155 Mbits/sec are under study.
Since Europe is a densely populated electromagnetic environment, interference rather than thermal noise becomes the limiting factor on uplinks to high G/T satellites. This fact has led to interest in satellite switched FDMA (SS/FDMA) and use of "expansion" uplink frequency bandwidth.
ESA has sponsored small terminal studies for VSATs and ultra small aperture terminals (USATs). These terminals, of the 0.5 m diameter antenna class, are intended for 300 bits/sec to 1200 bits/sec service for very low data rate data collection, and supervisory control (SCADA). For 4.8 kbits/sec, a 1.2 m antenna is recommended; and for 256 kbits/sec, 1.5 to 2.4 m apertures are under consideration. All terminals use SSPAs. It was implied that a series of standards might be developed to facilitate or stimulate commercial development of a VSAT terminal family. The classes are:
EUTELSAT is studying digital audio broadcast (DAB) at Ku-band. The WARC allocated 40 MHz for DAB, but there is no agreed standard of transmission.
EUTELSAT is very interested in development of standards for DBS HDTV transmission, recommendations for protocol changes for handling satellite time delays, and standards that would govern DAB.
EUTELSAT is a powerful entity in European satellite communications and operates, in effect, the European regional satellite segment. EUTELSAT has a significant role in support of country to country telephony, television broadcast distribution, and plays a growing role in business communications using VSAT networks and mobile communications over land.
Their EUTELTRACS system for vehicle communications has been introduced in a fashion timely to pan-European trucking, encouraged by such factors as the formation of the EC, the tunnel between England and France, and the post cold-war economy.
EUTELSAT has a far-reaching R&D effort aimed principally at efficient distribution and direct broadcast of HDTV, interfacing of satellite and terrestrial transmission (with reference to satellite propagation time delays), and introduction of new services, including personal and mobile communications.