Discrete Frequency

A separate radio frequency for use in direct pilot-controller communications in air traffic control which reduces frequency congestion by controlling the number of aircraft operating on a particular frequency at one time. Discrete frequencies are normally designated for each control sector in en route/terminal Air Traffic Control (ATC) facilities. Discrete frequencies are listed in the Airport/Facility Directory and the Department of Defense (DOD) FLIP Instrument Flight Rules (IFR) En Route Supplement. (FAA4)