Verifying that a correct program is being received and displayed on a television set of a consumer. In addition, video quality is checked to assure that transmission has not degraded the video quality. When the consumer requests a program by transmission of a message via a controller in a set top box...http://www.google.co.uk/patents/US5649283?utm_source=gb-gplus-sharePatent US5649283 - Program verification for cable television at a consumer location
