Patent ID: 8923118

Claim:
A method of performing clear channel assessment (CCA) in a communication system that utilizes at least a primary channel, a secondary channel, and a tertiary channel, the method comprising: measuring a primary channel signal level in the primary channel; measuring a secondary channel signal level in the secondary channel; measuring a first tertiary channel signal level in a first bandwidth portion of the tertiary channel; measuring a second tertiary channel signal level in a second bandwidth portion of the tertiary channel; determining whether the primary channel is idle based on the primary channel signal level; determining whether the secondary channel is idle based on the secondary channel signal level; determining whether a valid signal is received via a first composite channel including the primary channel and the secondary channel; determining whether the first composite channel is idle based on whether a valid signal was received via the first composite channel; determining whether the tertiary channel is idle based on the first tertiary channel signal level and the second tertiary channel signal level, wherein a bandwidth of the tertiary channel is at least twice a bandwidth of the primary channel; determining whether a valid signal is received via a second composite channel including the first composite channel and the tertiary channel; measuring a second composite channel signal level in the second composite channel at least when it is determined that a valid signal was received via the second composite channel; and determining whether the second composite channel is idle based on i) whether the first composite channel was determined to be idle, ii) whether the tertiary channel was determined to be idle, and iii) whether a valid signal was received via the second composite channel, wherein, at least when it is determined that a valid signal was received via the second composite channel, determining whether the second composite channel is idle is further based on iv) the second composite channel signal level.