A handover control executed when a location area of the mobile station is changed. The communication channel applied is the optimum route suited for the roaming destination of the mobile station. A service controller 6 is provided in the mobile communication network, switching node information transmitters 7 are provided in switching nodes 151, 131 and 132 so as to transmit, to the service controller 6, switching node informations representing the nodes themselves. Furthermore, in the service controller 6, a memory 8 for storing the switching node informations, and a handover execution unit 9 for executing handover control are provided. When a fixed terminal 5 in an external network and the mobile station 1 are in communication, and the location area of the mobile station 1 is to changed due to its roaming, the handover execution unit 9 specifies, on the basis of contents of the switching node information memory 8, the gateway conducting & switching node 151 to be the node utilized for the communication channel. Then, the unit 9 issues an instruction to assign a channel from the gateway conducting & switching node 151 to the subscriber switching node 132 in the location area which is the roaming destination.