Terminals and base stations belonging to service areas 100 to 102 of plural radio operators periodically measure a radio-link quality and an availability ratio of a radio link to notify them to a radio-resource management server 40. The server 40 alters a frequency of the base station, and a transmitted-power quantity of the base station and the terminal based on these measured results to improve the radio-link quality, and reduces interference with a neighboring radio system. When a load is concentrated on a network of a specific radio operator, an instruction of handover is given to the terminal from the server 40 to realize a load distribution within the radio operator, and between the radio operators. When the server 40 detects excessive radio interference between the radio operators, it notifies occurrence of a fault, an interference quantity, a quantity of the transmitted power that the base station should attenuate, and the frequency that the base station should alter to the above radio operator that becomes an interference source.