Patent ID: 8873562

Claim:
A system for indicating an IP Multimedia Subsystem (IMS) data flow in a mobile communication system, the system comprising: a terminal for, after a primary Packet Data Protocol (PDP) context for general purposes is generated, transmitting a secondary PDP context activation message including an IM CN Subsystem Media Flag stored in a Protocol Configuration Options (PCO) field, as a secondary PDP context to be used in an IMS system is generated; a Serving GPRS Supporting Node (SGSN) for receiving the secondary PDP context activation message and transmitting a secondary PDP context generation message including the IM CN Subsystem Media Flag when the IM CN Subsystem Media Flag is contained in the secondary PDP context activation message; and a Gateway GPRS Support Node (GGSN) for receiving the secondary PDP context generation message and determining that the secondary PDP context carries IMS data when there is the IM CN Subsystem Media Flag without an authorization token being generated by a Policy Decision Function (PDF); wherein the PCO field includes a Container ID to inform of the secondary PDP context including media data for an IMS service; wherein if the primary PDP context is dedicated to the IMS, the GGSN deletes the primary PDP context for the IMS and the secondary PDP context; and wherein if the primary PDP context is not dedicated to the IMS, the GGSN deletes the secondary PDP context.