A Session Initiation Protocol (SIP) Event Package and Data Format for Various Settings in Support for the Push-to-Talk over Cellular (PoC) Service

The Open Mobile Alliance (OMA) is defining the Push-to-talk over Cellular (PoC) service where SIP is the protocol used to establish half-duplex media sessions across different participants, to send instant messages, etc. This document defines a SIP event package to support publication, subscription, and notification of additional capabilities required by the PoC service. This SIP event package is applicable to the PoC service and may not be applicable to the general Internet. This memo provides information for the Internet community.