An uplink transmission band and a downlink transmission band that are allocated to each of a plurality of users are determined based on allocation information indicating allocation of a frequency bandwidth available to each of the plurality of users, and are output as uplink transmission band allocation information and downlink transmission band allocation information, respectively. Based on the downlink transmission band allocation information, downlink signals output from a plurality of wireless control devices toward a plurality of wireless devices for each of the plurality of users, and the uplink transmission band allocation information are multiplexed, and the multiplexed signal is demultiplexed into downlink signals for each of the plurality of users and the uplink transmission band allocation information. Based on the demultiplexed uplink transmission band allocation information, the uplink transmission band allocated to each of the plurality of users is changed, and uplink signals output from the plurality of wireless devices toward the plurality of wireless control devices for each of the plurality of users are multiplexed according to the changed uplink transmission band and then, the multiplexed signal is demultiplexed into the uplink signals for each of the plurality of users.