In a wireless base station, an installation information transmitter of the wireless base station transmits installation information indicating that the wireless base station is being installed, to the wireless network controller via an existing wireless base station. A connection information receiver receives connection information for connecting to the wireless network controller via a public network, from the wireless network controller via the existing wireless base station. An installation information receiver of the wireless network controller receives the installation information from the wireless base station via the existing wireless base station. On receiving the installation information from the wireless base station, a connection information transmitter transmits the connection information to the wireless base station via the existing wireless base station.