A macro eNB (MeNB) triggers a small cell (eLA eNB) to transmit a sequence on a second frequency band using a triggering command that indicates a time to transmit the sequence. On a first frequency band the MeNB triggers at least one user equipment UE to detect the sequence on the second band, and this trigger also has a first indication of when the sequence will be transmitted. From a second indication the MeNB receives on the first band from the at least one UE in response to the triggering of the UE the MeNB can determine whether the UE is located proximate to the small cell. The indication may be as little as a single bit indicating whether the UE detected or not the sequence. The first and second bands may be on first and second component carriers that may not be synchronized to one another, and the aperiodic nature of the triggered sequences and detection reports saves UE power.