A simple base station device is installed in the entrance or the like of a building and a power OFF signal is supplied. A portable telephone set that has received the signal informs the simple base station of its telephone number, also informs a position management server of the same via a public base station device to register it, the position management server being located in a radio network, and switches OFF power for a radio section. An incoming call operation to the portable telephone set is carried out by referring to the registered content of the position management server. Thus, a power supply for a portable telephone set in a use prohibition area is reduced and no incoming call control is performed.