Provided in the present disclosure are a spectrum management device and method, a geographic location database, a coexistence discovery device, and subsystems for use in a radio communication system comprising a main system and subsystems. The spectrum management device comprises: a processing circuit, which is configured to: acquire spectrum usage information and spectrum adjustment capability information of subsystems managed by the spectrum management device, the spectrum usage information corresponding to information related to used spectrums assigned to and used by each subsystem, the spectrum adjustment capability information corresponding to information related to whether the subsystems support a spectrum adjustment operation, and an adjustment of the spectrums of the subsystems managed by the spectrum management device is determined on the basis of the spectrum usage information and the spectrum adjustment capability information, thus the interference caused by the subsystems as a result of spectrum usage to the main system is limited within a permissible range of the main system. The spectrum management device and method, the geographic location database, the coexistence discovery device, and the subsystems of the present disclosure achieve highly efficient use of spectrum resources.