Importance

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Abstract

A public switched telephone network (PSTN) provides digital video signals from a video information provider to one or more of a plurality of subscriber premises. A subscriber uses either a standard telephone instrument over the PSTN or a dedicated control device over an ISDN packet network to order video programming. The request is transmitted to a designated video information provider and digital transmission connectivity is established between the video information provider and the central office serving the subscriber. Connectivity between the central office and subscriber is provided by asymmetrical digital subscriber line interface units over a local loop. The interface units frequency multiplex digital video information with voice information to the subscriber and support transmission of a reverse control channel from the subscriber to the central office for transmission on the ISDN packet data network back to the video information provider. The interfaces also allow base band signalling and audio between the central office and the subscriber for conventional telephone instrument connectivity.

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First Claim