Patent attributes
A frequency band FC assigned to a first wireless communication system and the frequency bands F1, . . . , Fm assigned to a second wireless communication system are set up for a base station apparatus 100. The base station apparatus 100 periodically performs a frequency detection process A to detect whether or not the frequency bands F1, . . . , Fm are usable for the communication with a mobile station 201. When the base station apparatus 100 and the mobile station 201 are communicating, the base station apparatus determines whether or not the frequency band used for the communication should be changed from FC to F1, . . . , Fm in accordance with its communication status. If it is determined that the frequency band should be changed, the frequency band used for the communication is changed to the frequency band determined as usable through the frequency detection process A.
