Abstract: A full service network (FSN) provides three communication channels that end between a headend and each set-top within the FSN, namely (1) forward-application-transport (FAT) channels that supply data from the headend to all or to only addressed ones of the set-tops, (2) a forward-data-channel (FDC) that supplies data from the headend to all or to only addressed set-tops, and (3) a reverse-data-channel (RDC) that supplies data from the set-tops to the headend. The FDC carries eight types of traffic, namely (1) conditional access message; (2) entitlement management messages; (3) broadcast data; (4) network management services messages or information; (5) general massaging; (6) application downloading; (7) Internet Protocol external device data services, and (8) VBR downloading. A fixed bandwidth FDC provides a first bandwidth portion for the high priority transmission of items (1), (2) and (3) at a continuous bit rate (CBR). All other items are transmitted over the FDC using at an available bit rate (ABR).

Abstract: An apparatus/method for descrambling a TV cable system transmission that been scrambled using an unknown scrambling algorithm. Insertion apparatus inserts a known visual/electrical characteristic into the TV transmission prior to scrambling by the unknown scrambling algorithm. The scrambled TV transmission, the scrambled insert-characteristic, and an encrypted message that defines the unscrambled insert-characteristic, are sent to all set-tops within the cable system. A set-top descrambler at each system-authorized set-top operates to descramble the scrambled insert-characteristic. The encrypted message is decrypted at each system-authorized set-top, to thereby reproduce the unscrambled insert-characteristic.