This paper describes the system components for modulation and demodulation of digital TV, the compression architecture and the highly flexible interface between the components. The complete system consists of a variety of products which can be combined together by a standardized interface (DVB). The principal of PID (Packed IDentifier) filtering ensures an easy way of multiplexing and remultiplexing of video-, audio- and data streams so that different streams can be guided to different systems components. The transmission data rate is 270 Mbit/s so that about 60 to 70 programms (4 Mbit/s per video) can be transported between the components, e.g. in cable headends. The system also integrates a return path channel for cable and a high sophisticated subscriber management, ordering and billing system for interactive services like video on demand (VOD). Examples of interactive solutions are given and are subject of further technical investigations.
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