METHOD AND APPARATUS FOR FACILITATING A PTT SESSION INITIATION USING AN IP-BASED PROTOCOL

摘要

Various embodiments are described to address the need for providing substantially reduced PTT call setup times and more efficient wireless bandwidth utilization for PTT sessions utilizing an IP-based protocol. The use of non-IP messaging between an originating MS ( 101 ) and PCF ( 131 ) and a target MS ( 102 ) and PCF ( 132 ), the use of IP-based messaging between the PCFs, the use of access channel signaling by the originating MS, and the generation of SIP responses by a target PCF on behalf of the target MS are described. Embodiments incorporating some or all of these protocol changes, can provide either, or both, reduced end-to-end call setup time for PTT as it presently exists in IS-2000 systems or reduced bandwidth consumption.