Patent ID: 7957287

Claim:
A method of internet-protocol (IP) multicasting in a wireless access network comprising: receiving, at a serving base station, a join request from a mobile station to join an existing multicast session, the join request being received on an open data connection identifier (CID) and including a multicast IP address of the existing multicast session the mobile station is requesting to join; receiving, at the serving base station, a dynamic service addition (DSA) request from the mobile station on a primary management CID, the serving base station to responsively establish a multicast CID for use on a link between the mobile station and the serving base station; transmitting IP multicast data encapsulated with the multicast CID; creating the multicast CID when the mobile station is a first mobile station served by the serving base station requesting to join the multicast session, and refraining from creating the multicast CID as a new multicast CID when one or more other mobile stations are currently being served by the serving base station as part of the existing multicast session; forwarding, by the serving base station, the join request to a router within an access service network (ASN) when the serving base station does not have internet group management protocol functionality; receiving a handover request for handing over the mobile station from the serving base station to a target base station, wherein in response to the handover request, the method further comprises: updating a multicast routing table at the router to map the multicast IP address of the IP multicast data from an IP address of the serving base station to an IP address of the target base station; determining, by the router, if other mobile stations being served by serving base station are currently receiving the IP multicast data by sending query messages to the other mobile stations; removing an entry from the multicast routing table for the multicast IP address when no responses are received to the query messages; and refraining from removing the entry from the multicast routing table for the multicast IP address when at least one response is received from the query message indicating that at least one of the other mobile stations is receiving the IP multicast data from the serving base station.