Combined Satellite Services

A novel satellite communications system providing broadband services in an efficient and cost-effective way is investigated under contract by Telekom Austria and in cooperation with the Institute of Computer Science (University of Salzburg). The advantages of communications satellites, namely the capability to broadcast large data volumes to an unlimited number of users is exploited by new multicast protocols and applications. The broadcast channel (server to client) makes use of the DVB (Digital Video Broadcasting) standard which is suitable for the transport of MPEG-coded video data and IP packets. Data rates up to 40 Mbit/s per channel can be supported. The evolving mass market for DVB/MPEG-2 equipment for digital TV reception leads to low-cost end-user equipment. A TDMA transmission system is used for the interactive return channel. A multi-service satellite gateway, developed for interactive video, voice and data applications provides bandwidth on demand on the return link. The combination of both technologies makes new satellite-based interactive services possible. For example, corporate headquarters can be interconnected to one virtual headquarter by the fully meshed TDMA system. DVB receive-only stations can be used to deliver data to branch offices or tele-workers. A Field trial with a representative user will be carried out in cooperation with Telekom Austria within the follow on project "Integrated LISSYsat/DVB service evaluation".