| 摘要 |
Systems, methods, and instrumentalities are disclosed to provide pre-negotiation of a video codec. An IP multimedia subsystem (IMS) entity, such as a service centralization and continuity application server (SCC AS), may send a first session initiation protocol (SIP) message to a circuit switched domain entity via an IMS core network. The first SIP message may correspond to a video call in an on-going IP multimedia subsystem (IMS) session. The first SIP message may include one or more video codecs supported by the SCC AS and the UE associated with the video call. The SCC AS may receive a second SIP message from the circuit switched domain entity. The second SIP message may include the video codec, which may be one of the video codecs included in the first SIP message. The SCC AS may send the video codec to a user equipment (UE) associated with the video call.
|
