Heterogeneous communication system and method for processing call in the same system

摘要

A communication system that manages heterogeneous networks including a Circuit Switched (CS) network and an Internet Protocol (IP) Multimedia Subsystem (IMS) network, and a method for processing a voice call in the communication system are provided. When a User Equipment (UE) requests the call setup by sending a Subscribe message including a subscriber identification number to a voice call management server of the IMS network, the voice call management server registers the UE in the IMS network and performs location registration in a Home Location Register (HLR) of the CS network using the subscriber identification number.