Patent ID: 8165055

Claim:
A method for transmitting a time stamp to provide a real-time multicast service by a base station in a communication system, the method comprising: (1) upon receipt of a multicast service request from a first terminal, determining whether a second terminal exists that was receiving data of the multicast service before the multicast service request is received from the first terminal; (2) determining whether the base station is transmitting the multicast service data to the second terminal in a unicast manner when the second terminal exists; (3) allocating a first multicast Connection Identifier (CID) and a first time stamp of an earliest order to the second terminal when the base station is transmitting the multicast service data to the second terminal in a unicast manner; after allocating the first time stamp to the second terminal, allocating the first multicast CID and a second time stamp having a next earliest order to the first terminal; and transmitting the first time stamp and the second time stamp using a resource allocation message; wherein the first time stamp and the second time stamp represent different playback times of the multicast service data.