METHOD AND SYSTEM OF USING IP MULTIMEDIA SYSTEM FOR CALL SETUP IN MOBILE SATELLITE SYSTEMS

摘要

A system and method of using IP Multimedia System (IMS) for call setup in Mobile Satellite Systems. The method begins by a unit equipment (UE) originating a call to a second party. Next, secondary Packet Data Protocol (PDP) Context is initiated after originating the call. At least a portion of progress and acknowledgement message exchanges are handled by a Satellite Session Initiation Protocol Gateway (SSGW) in a Mobile Satellite System (MSS) on behalf of the UE without communicating with the UE. The call is then connected between the UE and the second party. A simplified Session Description Protocol (SDP) may be implemented for use between the UE and the SSGW to reduce the payload of Session Initiation Protocol (SIP) messaging. With a simplified SDP, one codec of the second party may be pre- provisioned in the SSGW.