In one example, a first base station entity provides, to a second base station entity, a first indication of a reference signal that is transmitted by a first user equipment that the first base station entity is serving. The first base station entity obtains, from the second base station entity, a second indication of whether the second base station entity has detected the reference signal. Based on the second indication, the first base station entity determines whether the second base station entity is within a range of the first user equipment.