The Open Mobile Alliance (OMA) completed the Push to Communicate for Public Safety (PCPS), a push-to-talk (PTT) specification for Long Term Evolution (LTE) and is working with the Third Generation Partnership Project (3GPP) to integrate it into public-safety LTE standards. The specification is the foundation for mission-critical PTT (MCPTT) for LTE.
Read more: http://mccmag.com/onlyonline.cfm?OnlyOnlineID=522
Courtesy Mission Critical Magazine.