GATEWAY DEVICE, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD

摘要

A gateway device (110) comprises a communication section (111) for communicating an IuUP (Iu User Plane) protocol-compliant frame signal with a radio base station controller connected to a circuit switched network (101), a judgment section (112) for judging whether or not the frame signal received by the communication section indicates a time alignment request for requesting time alignment of the voice signal to the circuit switched network, a conversion section (113) for converting information included in the frame signal into information which should be set to a call control signal of an IMS (IP Multimedia Subsystem) in the case where the frame signal indicates the time alignment request, and a call control signal transmitting section (114) for transmitting the call control signal including the converted information to a communication device in an IMS (102).