A system capable of normally connecting a call without degrading the security level in a mobile terminal network, even in cases when a call addressed to a set of user equipment (UE) arrives via the Internet or a home network. In ST 101, a femto base station (110) receives a packet addressed to a set of UE (100) via the Internet or a home network and, in ST 102, starts a paging procedure. In ST 103, the set of UE (100) establishes an RRC connection to the femto base station (110). In ST 104, the UE (100) transmits, to the femto base station (110), a paging response addressed to the SGSN (150). In ST 105, the femto base station (110) performs NAS verification. If the femto base station (110) detects the paging response to a paging request made by itself, the femto base station (110), in ST 107, changes the service type of the service request received from the UE (100) from the paging response to signaling.