Uplink interference coupling is estimated between a first cell and a second cell by adjusting downlink interference coupling between the cells at least according to user equipment UE transmit power per physical resource block PRB. This estimated uplink interference coupling is used to decide whether to take a component carrier into use in the first cell. In various embodiments: the uplink interference coupling is estimated by adjusting the downlink interference coupling according to transmit power per PRB of a first UE in the first cell and transmit power per PRB of a second UE in the second cell; and by further adjusting the downlink interference coupling according to path losses of the first and second UEs; and the transmit power per PRB as well as the path loss of the second UE is determined from signaling received in the first cell from the second UE operating in the second cell.