METHOD AND APPARATUS FOR USE IN A COMMUNICATIONS NETWORK

摘要

A method is provided of registering a mobile node (4), such as a User Equipment (UE), 5 of a telecommunications network, such as a Universal Mobile Telecommunications System (UMTS), to a subsystem of the network, such as an IP Multimedia Subsystem (IMS). The network has at least one node (13-1, 13-2), such as a Policy and Charging Rules Function (PCRF), for maintaining or having access to policy and charging rules for users of the network. The network also has at least one node (10), such as a 10 Gateway GPRS Support Node (GGSN), for enforcement of the policy and charging rules to traffic flows. A registration request message, such as a Session Initiation Protocol (SIP) REGISTER message, is received from the mobile node (4) at a proxy node (12), such as a Proxy Call Session Control Function (P-CSCF), of the network. In response, a candidate policy and charging rules node (13-2) is selected for the mobile 15 node (4), and it is determined whether the candidate policy and charging rules node (13- 2) has already been selected by a policy and charging rules enforcement node (10) to serve the mobile node (4). Subsequent steps of the registration procedure are performed in dependence on the determination.