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TELEVISION VIA SATELLITE

By Hans-Dieter Naumann

This was followed on the very next orbit by TV transmissions in the opposite direction, from Goonhilly Downs in the UK back to Andover, where a 380t colos-sus in the form of a hoghorn an-tenna 30m high, 50m long and with a 20m circular radiating area picked up the weak signals.

These successful transmission experiments doubtless brought great joy to telecommunications experts on both sides of the Atlan-tic, since the hitherto unresolved problem of how to make real-time television transmissions across the "giant pond" had finally been solved, even if a technologically practicable implementation was still required. This solution was called "artificial earth satellites" and its practical implementation "geostationary orbit", which had already been proposed seventeen years earlier by the Englishman, Arthur C. Clarke.

However, anyone who at that time had dared to forecast that only a quarter of a century later satellites would be the mainstay of television transmission and pro-gramme distribution through to direct to the home (DTH) recep-tion by individual subscribers and that terrestrial transmission and distribution technology would play only a minor role, would have run the risk of being derided as a dreamer and visionary.

In actual fact, even the experts could hardly have foreseen what developed in the wake of the Tel-star experiments. Today, terres-trial transmission routes and transmitters play only a minor role. Only the most imposing tele-vision and radio towers in numer-ous cities or on mountain tops still remind us today that once, with their help a maximum of two to three TV channels could be broadcast into the home. Less than 10 per cent of households still rely on those towers for their television reception, the "rest" di-rect their gaze towards the sky, from where possibly hundreds of television and radio channels can be fetched into their living-rooms.

As for the "rest", at the turn of the century this included, for ex-ample, 87.5 million television households in 29 European coun-tries which were receiving their television transmissions entirely from the Astra system of orbiting satellites. 30.9 million of these had their own DTH sets and 56.6 mil-lion were receiving their broad-casts via satellite-fed cable net-works.

Eutelsat reports having 122 million subscribers in 38 countries in 2001, 98 million of whom are trained on the Hot Bird orbital position at 13ºE and on new-comer Eurobird. Other satellite operators in other regions simi-larly quote impressive statistics, for example the operators in both East and West that have formed strategic alliances with SES Global. Sirius provider Nordic Satellite AB (NSAB) supplies more than 5 million viewers in Scandinavia and the Baltic; Asia-Sat, the leading satellite system in the Asian-Pacific economic area, is provider to over 80 million households containing more than 300 million viewers; and StarOne Brasil, operator of the biggest sat-ellite fleet in Latin and South America (Brasilsat) supplies around seven million households just in Brazil.

If today we take it for granted that we can enjoy sporting events in other continents in real time, we have communications satellites to thank for it. In every applica-tion sector they are indispensable. It is therefore not surprising that TV transmission has developed into a driver of the technical de-velopment of the medium of tele-vision.

The digital television transmis-sion technology which is charac-teristic for present and future de-velopments owes its development to satellite transmissions. Ac-cording to German government forecasts, all broadcasts will be digital from 2010. Experts believe that this changeover will proceed at a much faster rate. Already since 2000 virtually all analogue programmes have also been broadcast digitally by satellite ("simulcasting"). However, up to now viewers have been adopting a stance of "wait and see". Accord-ing to data collected by Astra, only six per cent of German house-holds also received digital broad-casts in 2001.

It will thus take a lot of effort to develop the digital mass-market. It is not yet obvious to customers exactly what extra benefits digital technology offers, while the range of products is confusing, which does not exactly encourage pur-chasing decisions. However, studies expect the number of digi-tal households to grow by several millions per year.

European satellite television is today dominated by two provid-ers. These are Luxembourg-based SES Astra, a subsidiary of SES Global, and the European pro-vider organisation, Eutelsat SA, which is based in Paris. Astra pos-sesses three geo-positions with currently 13 satellites, to which a further two are to be added in 2002, and which include the most powerful so far, Astra 1-K. De-pending on serviceability and the remaining life of the older types, this means that up to 200 trans-ponders are available, capable of broadcasting up to 1000 television and radio channels.

Eutelsat only entered the DTH sector relatively late. The first two generations of Eutelsat were only intended for commercial tele-communication services, including programme feeds for cable net-works and transmissions of all kinds. However, the performance parameters of the Eutelsat II sat-ellites that were involved with the first also enabled reception by pri-vate households with antennae 80 cm diameter or more.

Perhaps it was the market seg-ment that developed unexpectedly as a result of this which now stimulated the operator to become more active in the DTH area. For this reason position 13ºE was de-clared the Hot Bird position for DTH reception in Europe and in 1995 it got its first satellite, to which a further four have since been added. Three more Hot Birds are to be stationed in 2002/2003.

Eutelsat now operates another European position at 28.5ºE with the satellite Eurobird, which is mainly used to provide pro-gramme feeds for cable systems but also appears to have potential as regards DTH reception. Moreover, successor services are being implemented from there to-gether with Astra at 23.5ºE for the former German telecommunica-tions satellite system, DFS Coper-nicus, which has in the meantime ceased operations.

Orbital positions 19.2ºE and 13ºE together with their co-positioned satellite fleets, are to-day the stars in the European TV satellite sky. Technological solu-tions have already been available for some time for the task of re-trieving them with a single system. The solution for free programme selection and distribution on vir-tually any terminal device is called multi-feed + multi-switch. "Multi-feed" means that there are two downconverters in the area of fo-cus of a mirror, whereby in each case one of them "squints" at one of the two satellites and the sec-ond is used for all-round pro-gramme distribution, enabling any subscriber to select the required satellite channel out of the hun-dreds that are available. Digital transmission technologies, multi-feed and multi-switch, in each case digitally controlled - it is here that the technological future of satellite television lies.

From page 46 of FLUG REVUE 2/2002