Patent ID: 8428042

Claim:
A method for providing a multicast/broadcast service (MBS) in a wireless OFDM/OFDMA system, comprising: operating a base station to transmit a scheduled MBS transmission to a plurality of subscriber stations over a single traffic channel based on a first data rate; causing a subscriber station to generate a negative acknowledgement (NACK) indication when the subscriber station fails to receive the scheduled MBS transmission from the base station; providing an uplink communication channel for the subscriber station to transmit the NACK indication to the base station which processes the NACK indication in determining a second data rate to be used in a subsequent MBS transmission to the plurality of subscriber stations over the single traffic channel based on the second data rate; applying a hash algorithm to a medium access control (MAC) address of the subscriber station to evenly assign different time and frequency components in the uplink communication channel to the subscriber station; operating the subscriber station to transmit one of a plurality of orthogonal codewords when indicating the NACK to the base station; and operating the base station to select the second data rate based on received information on the NACK indication from the plurality of subscribe stations that share the single traffic channel, including a service outage percentage among the plurality of subscribe stations during prior MBS transmission based on the first data rate, and to use the single traffic channel to send the subsequent MBS transmission to the plurality of subscriber stations at the second data rate, wherein the second data rate is less than the first data rate when the service outage percent is greater than or equal to a high outage percentage value; the second data rate is greater than the first data rate when a number of consecutive MBS transmissions are successfully received or when the service outage percent is less than or equal to a low percentage value; otherwise the second data rate is equal to the first data rate.