USER ROAMING METHOD AND ICS ENHANCED NETWORK

摘要

The present invention discloses a user roaming method, and a Bounds Proxy Function network element BPF is added in an IMS Centralized Service ICS enhanced network. The method includes that a Mobile Access Gate Control Function entity mAGCF sends a session invitation message to the BPF after receiving a call establish request message from a User Equipment UE of a non-ICS enhanced network; the BPF triggers a service control of a third side by a Local Initial Filter Control L-iFC, and transfers the received session invitation message to a Local Telephony Application Server L-TAS; the L-TAS triggers a service control of a Circuit Switching CS after receiving the session invitation message, and it acts as a UE proxy to establish a session with the opposite terminal after the trigger is successful. An ICS enhanced network is also disclosed in the present invention. The present invention enables a UE to access to a non-ICS enhanced network from an ICS enhanced network, enables a communication service for a UE of a non-ICS enhanced network, accordingly enabling the compatibility of a UE of a non-ICS enhanced network with an ICS enhanced network and enabling the service of a CS based on the IMS.