A mobile network system includes a guidance message control server, a call control server and a plurality of access gateways. The call control server includes a gateway management section that determines an access gateway as a subject of call restriction, a first instructing section that transmits a message transmission instruction to the guidance message control server and a second instructing section that transmits a call restriction instruction to the access gateway. The guidance message control server includes a receiving section that receives the message transmission instruction, an acquisition section that acquires a guidance message data and a transmission section that transmits the guidance message data to a specified multicast group. Each of the access gateways includes a processing section that performs multicast group participation processing for participating in the specified multicast group and a guidance transmission section that transmits the guidance message data to a mobile terminal.