Patent ID: 7020103

Claim:
A method of transmitting data in a digital communication system including a transmitting station, a relay station, and a plurality of receivers, said method comprising: transmitting from said transmitting station to said relay station a primary data signal containing a plurality of primary data packets, each said primary data packet intended for a specific one of said receivers; transmitting from said relay station said primary data signal over a broadband channel to said plurality of receivers; transmitting an index signal over a narrow band channel from said relay station to said plurality of receivers, wherein said index signal comprises a plurality of index data packets, each said index data packet corresponding to a respective one of said primary data packets and containing address information addressing a specific one of said receivers, said index signal extracted from said primary data signal; receiving and decoding said index signal at said plurality of receivers; determining and selecting, at each said receiver, those primary data packets in said primary data signal that are intended for said receiver based on address information in said index data signal; and extracting and decoding the selected primary data packets in said primary data signal at said plurality of receivers.