There are provided measures for channel access control. Such measures may exemplarily include obtaining a contention window assignment including at least an assignment of a size of a contention window for contention-based channel access, accessing at least one logical channel in a contention-based manner according to the contention window assignment, including allocating resources to the at least one logical channel for data transmission, and modifying the size of the contention window based on a result of the resource allocation in terms of an aggregated bit rate allocated for data transmission and an aggregate target bit rate requirement of prioritized bit rates of the at least one logical channel.