A mobile radio base-station is movable, has a radio resource control function, and includes an Internet-protocol (IP) communication interface. A plug-and-play server manages public radio base stations and mobile radio base-stations of a mobile telephone network, and is located on an operator network connected to an IP communication network. Upon power being turned on or reset operation, the mobile radio base-station notifies the plug-and-play server of position information of neighboring radio base stations. The plug-and-play server inquires the neighboring radio base stations specified based on the position information about radio-channel setting state. The plug-and-play server sets a radio channel of the mobile radio base-station based on radio-channel setting state of neighboring radio base-stations in the neighboring radio base stations.