Method of channel assessment and channel searching in a wireless network

A user device for performing channel assessment in a wireless network in which a high rate physical channel and a low rate physical channel are used for communication, the user device configured to:

• receive a beacon, which comprises a first information element for requesting assessment of a channel which is currently used, the beacon broadcasted by a coordinator of the wireless network, the first information element comprising a request type field that identifies a use of the first information element;
• decide whether to perform the channel assessment;
• transmit a response to the request of the channel assessment to the coordinator, the response confirming that the channel assessment will be performed by the user device;
• receive a beacon broadcasted by the coordinator on the low rate physical channel after transmitting 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;
• perform the channel assessment during the channel time block indicated by the information for allocating the channel time block;
• and
• transmit a result of the channel assessment to the coordinator.