Patent ID: 8570984

Claim:
A coordinator for controlling channel assessment in a wireless network in which a high rate physical channel and a low rate physical channel are used for communication, the coordinator configured to: broadcast a first information element to request assessment of a channel which is currently used in the wireless network, the first information element comprising a request type field that identifies a use of the first information element; receive a response to the request of the channel assessment from at least one user device of the wireless network, the response confirming that the channel assessment will be performed by the at least one user device which has decided to perform the channel assessment; broadcast a beacon on the low rate physical channel after receiving the response confirming that the channel assessment will be performed, the beacon comprising information for allocating a channel time block which is a time interval during which the channel assessment is to be performed, wherein data transmission by all user devices in the wireless network is not allowed during the channel time block; and receive a result of the channel assessment performed during the channel time block from the at least one user device.