An apparatus includes a report configuration controller configured to command reporting an event defined by receipt of a plurality of signals of different senders, wherein the signals are received at a same location, the signals are received with a strength above an absolute threshold, and a difference of the strengths is within a relative threshold. Another apparatus includes an aggregator configured to aggregate information reflecting an event defined by receipt of a plurality of signals of different senders, wherein the signals are received at a same location, the signals are received with a strength above an absolute threshold, and a difference of the strengths is within a relative threshold; and an aggregated information provider configured to provide the aggregated information.