Patent ID: 8509781

Claim:
A method for realizing session transfer, comprising: a service continuity application server (SCC AS), after receiving a session transfer request, when judging that a state of a session needed to be transferred is a held state, updating a remote leg by using a held state session state information, and notifying an enhanced mobile switching center (eMSC) that the state of the session needed to be transferred is the held state; and the eMSC completing a call setup of a target access network according to the held state, wherein, the step of the SCC AS notifying the eMSC that the state of the session needed to be transferred is the held state comprises: when the SCC AS judges that the state of the session needed to be transferred is the held state, rejecting the session transfer request, replying a rejection message carrying the held state session state information to the eMSC, and notifying the eMSC that the state of the session needed to be transferred is the held state; or, when the SCC AS judges that the state of the session needed to be transferred is the held state, and before replying a rejection message to the eMSC, notifying the eMSC that the state of the session needed to be transferred is the held state by carrying the held state session state information in a temporary response message or a notification message; after the SCC AS updates the remote leg, replying an acknowledgement message carrying the held state session state information to the eMSC, and notifying the eMSC that the state of the session needed to be transferred is the held state.