Data is transmitted from a first base station using a first sub-channel at a first power level. An indication that a first wireless device is in a potential interference location is received. The first wireless device is receiving data from a second base station. Data is transmitted from the first base station using the first sub-channel at a second power level when a second wireless device receiving data from the first base station on the first sub-channel is associated with an indicator of lower priority. The second power level is lower than the first power level.