Abstract:In the IMS(IP Multimedia Subsystem) specification of UMTS(Universal Mobile Telecommunications System) R6, the user must register its location in its home registrar. The session signaling have to reach its home registrar when user is not in home network, which results in the session path longer than the media path and defining the users to its home services. A new location management schedule and an auto-adjustable caching algorithm are proposed, so that the session signaling need not pass the home registrar but directly from original user’s visited network to terminate user’s network. The results of Simulation and analysis shows the new schedule get the benefit in cost and time.