Mobile communication system

摘要

Provided is a mobile communication system that can switch between a first communication state and a second communication state. In the first communication state, VoIP media signals are exchanged between a mobile station (UE #1) and a mobile station (UE #2) via an LTE wireless access system and a node (S-GW), and VoIP control signals are exchanged via the LTE wireless access system, the node (S-GW), and an IMS. In the second communication state, circuit-switched signals are exchanged between the mobile station (UE #1) and an expanded MSC/MGW via a 2G/3G wireless access system; VoIP media signals are exchanged between the expanded MSC/MGW and the mobile station (UE #2) via the node (S-GW); and VoIP control signals are exchanged between the expanded MSC/MGW and the mobile station (UE #2) via the node (S-GW) and the IMS.