A feasibility study on mission-critical push-to-talk: Standards and implementation perspectives

In this article, we study feasibility issues of mission-critical push-to-talk (MCPTT), which is an evolution of a group communication service for public safety use. Along with the overall standardization of the MCPTT in the Third Generation Partnership Project (3GPP), distinguishing features of MCPTT are investigated in comparison with Open Mobile Alliance (OMA) PTT over cellular (PoC). Based on the requirements of MCPTT, we elaborate on various technologies that need to be leveraged for minimizing end-to-end latency in terms of both communications and application processes. To validate MCPTT in practice, we show not only the realization of MCPTT with a practical testbed but also the verification with key performance indicators defined in the 3GPP specification as performance metrics. The results from our proof of concept reveal that MCPTT can be a reasonable candidate for group communication, guaranteeing a sufficient level of survivability and immediacy beyond its potential.