Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine an adjusted contention window size for a listen-before-talk (LBT) procedure that increases channel access time fairness between a plurality of different groups of UEs. The UE may determine, via the LBT procedure, that a channel is idle based at least in part on the adjusted contention window size. The UE may transmit, to other UEs in a group of UEs that includes the UE, control information that enables a group channel occupancy time (COT) associated with the channel to be shared with the other UEs in the group of UEs. Numerous other aspects are described.