A method and system for processing a Push To Talk (PTT) call at an alternate bearer gateway. The alternate bearer gateway is connected to a Land Mobile Radio (LMR) Core Network and a Broadband Network. The alternate bearer gateway receives a PTT message from either the LMR Core Network or the Broadband Network. The PTT message includes a talkgroup identifier and a message. When the PTT message is received from the LMR Core Network, the alternate bearer network determines at least one Broadband talkgroup member using the talkgroup identifier. The alternate bearer gateway sends the message to the Broadband talkgroup member via the Broadband Network. When the PTT message is received from the Broadband Network, the alternate bearer gateway sends the message to the LMR Core Network.