Patent ID: 8005480

Claim:
A communication initialization method for a base station (BS) in a Cognitive Radio (CR) communication system having a service area overlapped with a service area of at least one licensed communication system which provides a communication service in a licensed frequency band, the method comprising: sensing, by the BS, available frequency bands for providing a communication service from the BS; detecting unused frequency bands that are not used for the at least one licensed communication system or other CR communication systems; and preparing for providing the communication service to customer premise equipments (CPEs) in the unused frequency bands; wherein the preparing comprises: sending periodically a first ready-to-use (RTU) signal in the unused frequency bands; receiving channel report signals from the CPEs in response to the first RTU signal; and selecting a channel for providing the communication service according to the channel report signals, wherein the first RTU signal, having a predetermined pattern sensible to the other CR communication systems, is sent with narrower bandwidth than each frequency band, the first RTU signal including a Base Station Identification (BSID), a Training Frequency Set (TFS), and a Training Sequence Signal (TSS), wherein each of the channel report signals includes an ID of a CPE, a Current Band Channel Metric (CBCM) indicating the channel status of each of the frequency bands in which the first RTU signal was sent from the BS, and a Not Available Training Frequency Set (NA-TFS).