Patent ID: 7415284

Claim:
In a push-to-talk communications network, a method of transmitting a first message from a sending push-to-talk over cellular (PoC) client to a set of receiving PoC clients, comprising: selecting said set of receiving PoC clients from a contact list on said sending PoC client, such that each of said receiving PoC clients has an address on said contact list; transmitting said first message to a message server, wherein said sending PoC client is coupled to said message server, and wherein said message server is a DVM server; storing said first message within said message server; assigning said first message an identifier; notifying said set of receiving PoC clients that said first message can be retrieved, wherein each of said set of receiving PoC clients is coupled to said message server, wherein a PTT-specific AdhocGroupRequest parameter in a SIP TO header of said message is replaced with a DVM specific SIP URI, wherein said DVM specific SIP URI is used as the value of said AdhocGroupRequest parameter by selecting a particular entry on a contact list by a sending PoC client user, and wherein a DVM specific SIP URI is added to said contact list via a back-end function.