NETWORK INTERWORKING SYSTEM AND METHOD FOR PROVIDING SEAMLESS VOICE SERVICE AND SHORT MESSAGE SERVICE BETWEEN WIRELESS COMMUNICATION NETWORKS, AND PACKET SWITCH APPARATUS THEREFOR

摘要

A network interworking system is provided for connecting a voice call between a mobile terminal in a wireless packet network that provides VoIP service and a mobile terminal in a mobile communication network that provides circuit-switched service. A home location register (HLR) registers therein location information of terminals and a subscriber profile. A packet switch or a mobile switching center (MSC), in which a calling terminal is located, transmits a call connection request to a location of a called terminal, detected through the HLR, upon receiving an origination message including a terminal identifier of the called terminal. An MSC or a packet switch, in which the called terminal is located, transmits a message for voice call connection to the called terminal upon receiving the call connection request for the called terminal.