Patent ID: 8179908

Claim:
A method for session changing, adapted to change a session during interworking between a first UE and a second UE in a packet network, comprising: reserving, during setup of an initial session between the first UE and the second UE, an interworking control function for controlling the interworking, on a path of the initial session; and when a subsequent session change request is received, performing, by the interworking control function, a corresponding session changing operation according to contents of the subsequent session change request; wherein, the contents of the session change request comprises at least one of: removing at least one media component from a plurality of media components included in the initial session; adding at least one media component to the initial session; and processing upon a change on a media bearing part of the initial session; wherein, the media components comprise a real-time media component and a non-real-time media component; wherein, the session changing operation comprises at least one of the following operations: 1) if the real-time media component of the session with the first UE is to be removed, the interworking control function releases a Circuit Switch call with the first UE; 2) if the non-real-time media component of the session with the first UE is to be removed, the interworking control function initiates a change on media of an original non-real-time IMS session with the first UE, to remove the non-real-time media component from the media; 3) if the real-time media component of the session with the first UE is to be added: if a CS call with the first UE exists, adding of real-time media fails for this time; and if no CS call with the first UE exists, the interworking control function initiates a call to a CS part of the first UE, and the CS call is to be used to bear the real-time media component; 4) if the non-real-time media component of the session with the first UE is to be added: if no IMS session with the first UE exists, the interworking control function initiates a new non-real-time IMS session with the first UE; and if an IMS session with the first UE exists, a change on the original non-real-time IMS session with the first UE is initiated, to add a new non-real-time media component; 5) if the media bearing part for the session with the first UE is changed, the interworking control function initiates a change on information of media bearing for the session with the second UE; and 6) if the media bearing part of the session with the second UE is changed, the interworking control function initiates a change on information of media bearing for the session with the first UE.