CALL CONTROL FOR MOBILE STATION IN IP ENVIRONMENT

摘要

A client application installed in a mobile station (MS1) monitors broadband networks (WLAN) available in the area. When a call is set up from the mobile station (MS1), the application intervenes in all outgoing calls and if a broad¬ band network (WLAN) is available, it enquires a voice server (2) whether a called subscriber (MS2) is reachable by a VoIP call over the broadband net¬ work. If the called subscriber (MS2) is reachable by a VoIP call and a VoIP call over the broadband network is economically and technically reasonable, the voice server (2) controls the mobile station (MS1) to set up a VoIP call. If the called subscriber (MS1) is not reachable by a VoIP call or not in a network rea¬ sonable for a VoIP call, the voice server (2) controls the calling mobile station (MS1) to set up a normal circuit-switched mobile call (CS).