| 摘要 |
<p>A digital headend architecture and full service network are provided to selectively demodulate and decode a variety of digital and analog feeds into baseband signals or pass digital programming through the headend. In accordance with one embodiment, the head end is provided with digital-turn-around capability to allow precompressed signals to passed through the headend without any decompress or decoding into baseband signals. The headend includes at least one receiver for receiving signals sent by satellite, at least one antenna (18) for receiving over-the-air signals as baseband composite video and audio signals, and a decoder connected to the at least one receiver for converting received satellite signals into baseband video and audio signals. At least one MPEG encoder (34) is provided for encoding the baseband video and audio composite signals into multiplexed (40) Single Program Transport Streams (SPTS). A remultiplexer (60) is arranged to ATM encapsulate the SPTS, while an ATM switch (62) outputs the ATM encapsulated SPTS for distribution over a fiber optic network.</p> |
