Patent ID: 8509696

Claim:
A radio communication system, which is a first radio communication system, comprising a plurality of cognitive radio apparatuses, wherein one of the cognitive radio apparatuses comprises: a transmission/reception section; a detection section configured for detecting a radio wave which is transmitted from a second radio communication system which is different from the first radio communication system and which is unable by the radio communication system; a control section configured for determining a frequency band on which each cognitive radio apparatus detects the radio wave and; a storage section configured to store frequency allocation information that shows which divided frequency band was allocated to each cognitive radio apparatus as a target band of detection in the past, wherein the control section comprises: a frequency band allocation section for assigning the following frequency bands on which the plurality of cognitive radio apparatuses of a radio apparatus group deal with the detection, with reference to the information on the frequency band on which each cognitive radio apparatus has dealt with the detection in the past and the detection result both of which are stored in the storage section; an examination section for examining whether or not the following frequency bands determined by the frequency band allocation section are available; and a subgroup division section configured for forming subgroups from the radio apparatus group with reference to the information on the frequency band on which each cognitive radio apparatus has dealt with the detection in the past and the detection results, which are recorded in the storage section, and the frequency band allocation section determines, for each subgroup, which frequency band is assigned to cognitive radio apparatuses of the subgroup to deal with the detection.