METHOD AND APPARATUS FOR COMMUNICATIONS OF USER EQUIPMENT USING INTERNET PROTOCOL ADDRESS IN A MOBILE COMMUNICATION SYSTEM

摘要

A method and apparatus for communications of a UE using an IP address in a mobile communication system are provided. When the UE moves from an old subnet managed by an old gateway to a new subnet managed by a new gateway, the UE determines whether there are allocated radio resources. In the absence of the allocated radio resources, the UE determines whether an IP-based application service is in progress. If the IP-based application service is in progress, the UE determines to reuse an old IP address in the new subnet. If the IP-based application service is not in progress, the UE determines to use a new IP address in the new subnet. Then the UE sends to the new gateway an RAU request message including an indication indicating whether the old IP address or the new IP address will be used in the new subnet.