COMMUNICATION SYSTEM

摘要

A Proxy Call Session Control Function, P-CSCF, comprises a transceiver and a controller. The transceiver receives a register request from a user equipment, UE, in a visited public land mobile network, VPLMN. The controller retrieves a network identifier, PLMN ID, for the VPLMN, queries a database for any local emergency number(s), and includes the PLMN ID for the VPLMN in a header and forwards the register request to a Serving Call Session Control Function, S-CSCF.