System and methods for distributed connection and mobility processing in a multicast IP network incorporating multi-cell location areas

摘要

A wireless communication system 200 comprises a connectionless packet network 201 coupled to a plurality of sites 203-208 that are in location areas 260, 261. The sites join respective location area multicast addresses to receive messages from other sites in their location area. Communication units desiring to participate in talkgroup calls need only to register affiliation with a first site of the location area. Upon the first site receiving an affiliation message, it joins a payload multicast group address to receive payload for the talkgroup. In alternative embodiments, the first site sends, via the location area multicast address, either control message(s) or tunneled payload associated with the talkgroup call to secondary site(s) of the location area. The sites initiate paging sequences to determine whether communication units at their sites desire to participate in the call and, based on the responses, the sites may deliver stored payload and/or join the payload multicast group address to receive payload for the call. In this manner, a centralized entity such as a VLR is not needed to keep track of communication units in the location area.