De-registration method and system for IP multimedia subsystem centralized service

Abstract

A de-registration method and system for IP Multimedia Subsystem (IMS) centralized service are provided in the present invention, wherein the method comprises: a Circuit Switched User Equipment (CS UE) moves from a source enhanced Mobile Switch Centre Server (eMSC Server) into the control area of a target Mobile Switch Centre Server (MSC Server); during a location cancelling process in which the CS UE changes the MSC Server to which it is attached, the source eMSC Server starts up delay timing after receiving a location cancelling request; when the delay time is reached, the source eMSC Server performs the de-registration of the IP Multimedia Subsystem (IMS) instead of the CS UE. The method and system of the present invention ensure that the de-registration request of the source eMSC Server arrives at the Serving Call Session Control Function (S-CSCF) later than the registration request of the target MSC server, so as to avoid unnecessary redundant signaling and improve the system processing efficiency.

Dependencies are inferred from the claim text.