| 摘要 |
PROBLEM TO BE SOLVED: To provide a mobile communication network in which pre-registration by a terminal information management section and a user is unnecessary and a communicable range between mobile terminals is determined as a wide range to RNC when transmission/reception of a control signal with HSS and CSCF is impossible.SOLUTION: A mobile exchange station 200 has: a VLR which is arranged between an IMS network 1 and a radio access network 2, mutually converts call control signals between mobile terminals respectively, relays transmission/reception of the call control signals between the IMS network and the radio access network, and temporarily stores area information indicating location information of the mobile terminal and subscriber information on the mobile terminal under control of the station itself; and a RAN call control device which performs a call control in the radio access network on the basis of the information to be stored in the VLR. The mobile exchange station 200 also has a control section which determines presence/absence of a communication failure generation in the IMS network and, when determining that a communication failure is generated, switches a transmission destination of the control signal to the RAN call control device from the IMS network. |
