There is provided a method, performed by a network node associated with at least two wireless communication devices, for scheduling packet transmission over a radio-based medium. The method comprises sensing (S1) the radio-based medium by estimating a received signal level, and evaluating (S2), for each of the at least two wireless communication devices, whether the radio-based medium is accessible or free for transmission based on comparing the received signal level to a respective threshold associated with the considered wireless communication device. The method further comprises scheduling (S3) packet transmission over the radio-based medium based on the evaluating, for each of the at least two wireless communication devices, whether the radio-based medium is accessible or free for transmission.