A
clear-channel station is an
AM radio station in
North America that has the highest protection from
interference from other stations, particularly concerning night-time
skywave propagation. The system exists to ensure the existence of cross-country or cross-continent radio service, and is enforced through a series of treaties and statutory laws. Now known as
Class A stations since 1982, they are occasionally still referred to by their former classifications of
Class I-A (the highest classification),
Class I-B (the next highest class), or
Class I-N (for stations in
Alaska too far away to cause interference to the primary clear-channel stations in the lower 48 states). The term "clear channel" is used most often in the context of
North America and the
Caribbean, where the concept originated.