a typical dme ground based responder beacon has a limit of 2700 interrogations per second (pulse pairs per second – pps). this means that it can provide distance information for up to 100 aircraft at a time—95% of transmissions for aircraft in tracking mode (typically 25 pps) and 5% in search mode (typically 150 pps). above this limit the transponder avoids overload by limiting the sensitivity (gain) of the receiver. replies to weaker (normally the more distant) interrogations are ignored to lower the transponder load.