METHODS AND APPARATUS FOR REGISTERING OR DEREGISTERING A USER TO OR FROM AN IP MULTIMEDIA SUBSYSTEM

摘要

A method of registering or deregistering a user to or from an IP Multimedia Subsystem network. The method comprises performing a Session Initiation Protocol registration or deregistration on the user's behalf by a Session Initiation Protocol Application Server. Registration or deregistration is performed over one of the following interfaces: the Service Control Interface (ISC) with the Serving Call State Control Function; the Gm interface with the Proxy Call State Control Function; or the Ma interface with the Interrogating Call State Control Function.