The present invention relates to a wireless communication method in a wireless network comprising an access point and stations. The method comprises, at a station: receiving a trigger frame from the access point, the trigger frame reserving a transmission opportunity on at least one communication channel of the wireless network, the transmission opportunity including a random resource unit that the stations may access using a contention scheme; receiving parameters of the contention scheme in management frames from the access point, the parameters comprising a contention window range; contending access to the random resource unit of the transmission opportunity reserved by the received trigger frame, using a contention window value; and updating the contention window value based on the success or failure of the access to the random resource unit. The updated contention window value remains within the contention window range obtained from the most recently received contention scheme parameters.