Patent ID: 8238310

Claim:
A system for relaying Multicast Broadcast Service (MBS), comprising: a base station; and a plurality of relay stations, wherein the relay stations forms multi-hop relay network, wherein the base station selects a Modulation and Coding Scheme (MCS) level among a plurality of MCS levels based on channel condition between the base station and the respective relay stations, wherein the base station receives information on the channel condition to select the MCS level through Channel Quality Information Channel (CQICH) from the relay stations at a predetermined period, wherein the base station decides, based on the information on the channel condition, whether the MCS level is updated, and wherein, if the base station decides to update the MCS level, the base station transmits test MBS data of plural MCS levels to the relay stations, receives, from the relay stations, feedback information in response to the test MBS data, decides an updated MCS level based on the feedback information, and transmits MBS data with the updated MCS level to the relay stations.