Patent ID: 7349359

Claim:
A method for transmitting a Broadcast/Multicast Service (BCMCS) content frame in a mobile communication system connected to a BCMCS server, the method comprising: receiving, by a Packet Data Service Node (PDSN), a BCMCS content frame from the BCMCS server, and transmitting a corresponding Generic Routing Encapsulation (GRE) packet BCMCS content frame, including a sequence number and a timestamp value; and determining, by each of first lower nodes, whether the GRE packet BCMCS content frame received from the PDSN is valid, based on the sequence number included in the received GRE packet BCMCS content frame and, if the GRE packet BCMCS content frame is valid, transmitting the GRE packet BCMCS content frame from each of the first lower nodes to second lower nodes connected downstream of each of the first lower nodes, while synchronizing the transmission of the GRE packet BCMCS content frame, based on the timestamp value included in the GRE packet BCMCS content frame.