Interworking between Mission-Critical and Non-Network-Based Push-to-Talk Services

Tiami LLC aims to develop a broadband Push-to-Talk (PTT) interoperability platform that interconnects non-network-based and mission-critical PTT (MCPTT) networks. Non-network-based PTT (NPTT) services are typically deployed as Over-the-Top (OTT) applications that connect to the network using cellular or Wi-Fi access, whereas MCPTT networks are deployed by mobile network operators based on Third Generation Partnership Project (3GPP) specifications. This form of interworking is not specified either in 3GPP or in the Open Mobile Alliance (OMA) that developed PTT over Cellular (PoC). Tiami’s solution is to design a broadband interworking function (BIWF) that exploits existing 3GPP and OMA architecture interfaces to route MCPTT calls to NPTT users and vice versa while preserving meta data and encryption of services. The two major benefits of this approach are:
• A step toward seamless PTT interoperability via a standards-based broadband interface that uses existing OMA and 3GPP reference points to facilitate implementation.
• Economic benefits since existing NPTT and MCPTT devices do not need to be replaced or upgraded to achieve interoperability.