Definition
A separate radio frequency assigned for communication between a specific air traffic control position (or facility) and one or more aircraft, used to reduce frequency congestion on busier shared frequencies.
Plain English
A dedicated radio channel given to you so you can talk to a specific controller without sharing the airwaves with everyone else.
Context Anchor
You will see or hear this term in ATC communications, chart notes, and instructions to contact a controller on a specific frequency.
Derivation
Discrete comes from the Latin discretus, meaning 'separated' or 'set apart.' In radio use, it points to a frequency that has been set aside for a particular purpose rather than shared by many users.
Why Pilots Care
Prevents overlapping transmissions and missed calls by keeping each facility on its own clear channel.
Intuition Check
Discrete does not mean secret or hidden here. It means separate and specifically assigned.
Example Sentence 1
After departure, the tower handed us off to a discrete frequency so departure control could work us individually.
Example Sentence 2
Each tower publishes its own discrete frequency so pilots can reach it without sharing the channel with other airports.