In femtocell operation, when a wireless communication terminal whose ID is not registered (ID unregistered terminal) has entered a femtocell's area, the disclosed invention prevents interference between the femtocell and the ID unregistered terminal and interference between the ID unregistered terminal and an ID registered radio communication terminal and prevents a decrease in the throughput of the femtocell and these terminals. In a radio coverage area formed by a radio base station, if a drop of received power from a radio communication terminal occurs and the frequency of reporting the ID of the base station now communicating with the terminal has become less than a given value, it is decided that the terminal is located indoors. For the terminal, if its handover to a femtocell was found to be rejected by MME, the terminal is temporarily permitted to be handed over to a femtocell.