SKYPLEX is a new processor that allows a stream of multimedia information such as video, audio and data to be packaged on board a satellite. Traditionally, the various multimedia signals would need to be conveyed through standard communication networks to a ground multiplexing centre where they are combined into a single high-rate multi-programme stream and transmitted to the satellite. Thanks to SKYPLEX, the satellite can instead be accessed directly, broadcasting is greatly simplified and costs are reduced, so that many more broadcasters and service providers will be able to make use of satellite systems.
The first SKYPLEX system is mounted on board the Eutelsat Hot Bird 4 satellite which will be launched on Ariane Flight 106, scheduled for 27 February.
Any television production facility, radio station or Internet provider can directly access the satellite: a system the size of a low-cost satellite news-gathering station (typically a 1.8 m dish and a 50 W transmitter) is sufficient to uplink to the satellite. The SKYPLEX processor on board Hot Bird 4 demodulates the incoming low-rate signals and re-combines them into a single, high-rate multi-channel digital broadcast signal which is transmitted directly to users' homes.
Transmission is fully compliant with the existing European digital television standard and therefore the SKYPLEX signal is indistinguishable from a conventional Direct-To-Home signal and can be received by any standard digital TV receiver.
SKYPLEX payloads are being mounted on Eutelsat's Hot Bird 4 and Hot Bird 5 satellites, the latter scheduled to be launched this summer. The SKYPLEX processor can assemble six uplink carriers with a net bit rate of 6 Mbit/sec each into a down-link stream of 36 Mbit/sec. The Hot Bird 5 version can also accommodate lower bit rates, down to 1 Mbit/sec, using advanced time division multiple-access techniques.
The SKYPLEX system is the result of a cooperative venture between ESA and Eutelsat. The first model of the SKYPLEX payload has been developed under an ESA contract. The Hot Bird prime contractor Matra Marconi Space (France-UK) has been responsible for the satellite interface whilst the payload prime contractorship was awarded to Alenia Aerospazio (I), with Alcatel Espacio (E), Mier Comunicaciones (E) and AME Space (N) as sub-contractors. The first model of the ground facilities has been developed by Newtec (B).
The SKYPLEX programme is an example of how ESA, in partnership with industry and operators, aims to develop Europe's satellite multimedia market. The SKYPLEX programme is also an example of how success-oriented cooperation with industry leads to very short time-to-market initiatives (less than 20 months from contract signature to launch).
In its recently launched multimedia activities, ESA is negotiating the development of a second-generation SKYPLEX processor which will be designed to reduce costs and to provide new Internet-ready functionality to cope with interactive multimedia communications. This next generation will be available in late 1999.
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