Patent ID: 8233422

Claim:
A multicast site architecture for communicating land mobile radio (LMR) content, said multicast site architecture comprising: a plurality of communication sites; and an LMR over Internet Protocol (IP) interface associated with at least one communication site of said plurality of communication sites, said LMR over IP interface configured to: transmit call control and signaling information to a plurality of LMR units using at least one control multicast IP address, assign a different traffic multicast IP address to each of a plurality of talkgroups for communicating LMR content between LMR units of said plurality of LMR units which subscribe to at least one of said plurality of talkgroups, identify at least one talkgroup of said plurality of talkgroups having an active communication within said at least one communication site, determine if an LMR unit, which is not currently participating in said active communication, is a subscriber to said at least one talkgroup, identify a traffic multicast IP address that is assigned to said at least one talkgroup, and communicate said traffic multicast IP address to said LMR unit only if it is determined that said LMR unit is a subscriber to said talkgroup.