METHOD AND APPARATUS FOR AN INTERNET PROTOCOL MULTIMEDIA SUBSYSTEM-BASED THREE-WAY CALL

摘要

Communication system 100 provides an Internet Protocol Multimedia Subsystem (IMS) based three way call. The mobile station (MS) (104) receives the invitation to join the call, and decides to transfer the call to a three-way call. MS sends a request to transfer the call to the conference call to the IMS network (150). IMS network server 168 receives the request, determines the unique identifier for the conference call, the conference call identifier for a session initiation protocol (SIP) Refer message, one of the SIP message, the message and the SIP 200 OK message, or through a more provide to the MS. In response to receiving the conference call identifier, the MS requests the conference call connection, and also to connect a call initiated (102). Next, IMS network, and the server requests that the dialing call initiator, and in response to self-dialing call initiation.