Patent ID: 6970449

Claim:
A communications system comprising: a gateway operable to receive a first packet addressed to a mobile unit, to determine a multicast address associated with the mobile unit, to generate a second packet having information from the first packet and addressed to the multicast address, and to communicate the second packet to a packet network; a plurality of base transceiver stations each operable to receive the second packet from the packet network, to determine the mobile unit identified by the second packet, and to communicate information from the second packet to the mobile unit; and a roam management module operable to monitor, for each of the base transceiver stations, a wireless link between the mobile unit and the base transceiver station, to determine that radio link quality of the wireless link for a first one of the base transceiver stations has fallen below a first threshold, and to withdraw the first one of the base transceiver stations from a multicast group associated with the mobile unit, the roam management module further operable to determine that radio link quality for the wireless link between a second one of the base transceiver stations and the mobile unit has exceeded a second threshold and to register the second one of the base transceiver stations with the multicast group.