US 4,994,909 AGranted

Video signal distribution system

AssigneeNorthern Telecom Limited

InventorsAlan F. Graves, Robert C. Dittburner, Barry B. Hagglund

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Abstract

A signal distribution system is disclosed for distributing television program signals from a central location to a plurality of subscriber locations via respective optical fibers. At the central location, 4 of 64 signals are selected and multiplexed for delivery to each subscriber location. At each subscriber location, an interface unit selects any 2 of the 4 signals for delivery to each of a plurality of video port controllers, for supply to an associated television receiver and video cassette recorder. Requests for program signals initiated by a subscriber at a video port controller are handled by the interface unit, being granted, denied, or fowarded to the central location as appropriate. The system facilitates the provision of pay-per-channel and pay-per-view television program signals.

Claims9

Dependent claims

A signal distribution system for distributing video signals from a central location to a plurality of subscriber locations via respective communications paths, the system comprising, at the central location:

means for selecting for each subscriber location, from a first plurality of video signals a second, lesser, plurality of video signals and for delivering said second plurality of video signals to the respective subscriber location via a respective communications path;
and, at each subscriber location:
a plurality of control means each for supplying a respective video signal to at least one respective video signal receiver associated therewith;
and
interface means coupled to the respective communications path and to each control means for delivering respective video signals thereto;
wherein each control means comprises means for requesting delivery of any of the first plurality of video signals and for communicating such request to the interface means, and wherein the interface means comprises means responsive to such request for:
determining whether the requested video signal is one of said second plurality of video signals delivered thereto via the respective communications path;
if so, delivering the requested video signal to the respective control means;
and
if not, communicating a request for the requested video signal to the central location to be selected from the first plurality of video signals and delivered as one of the second plurality of video signals.

7 more elements

Dependencies are inferred from the claim text.