Patent ID: 7496061

Claim:
A method to provide a multicast service to a mobile node, comprising: receiving a first request to join a multicast group, the first request requesting that a first mobile node serviced by a first cell site be permitted to join the multicast group; identifying a first multicast source that operates to provide content to the first mobile node; associating the multicast group and the first multicast source to yield a first group-source combination; assigning, by a gateway, a first key to the first group-source combination; providing the first key to the first cell site; receiving a second request to join the multicast group, the second request requesting that a second mobile node be permitted to join the multicast group; identifying a second multicast source that operates to provide the content to the second mobile node; associating the multicast group with the second source to yield a second group-source combination; assigning a second key to the second group-source combination; receiving a third request to join the multicast group, the third request requesting that a third mobile node serviced by a third cell site be permitted to join the multicast group; establishing that the first multicast source operates to provide the content to the third mobile node; and providing the first key to the third cell site.