A method determining indication of an occupancy level in a mobile communications system including a base station to communicate with a mobile communications device via a wireless interface provided by a first frequency channel allocated to mobile networks communications for the mobile communications system and by a shared channel which can be shared by the mobile communications system and by other wireless communications systems. The method includes: a mobile communications device: measuring, for each of plural first time periods within a second time period, a channel utilization on the shared channel; determining channel occupancy states for the shared channel for each of the first time periods based on the measured channel utilization; and determining an indication of an occupancy level for the shared channel for the second time period, the indication of an occupancy level determined based on the occupancy states for the shared channel for each first time period.