A method for use in a wireless communications system in which there is at least a first mode which controls the traffic to and from user terminals in a cell within the system, so that there is downlink traffic in the system. The first node transmits downlink traffic in radio frames, each of which comprises sub-frames. The first node performs measurements on pre-defined system indicators in at least said first cell, and based on the results of said measurements, the first node is allowed to autonomously decide to vary the number of available down link sub-frames used for down link traffic in said down link radio frames and also to vary the content of the down link sub frames which are used, said decision being valid for a time which is specified by the first node.