Combat-net radio

In telecommunication, a combat-net radio (CNR) is a radio operating in a network that (a) provides a half-duplex circuit and (b) uses either a single radio frequency or a discrete set of radio frequencies when in a frequency hopping mode.

Note: CNRs are primarily used for push-to-talk-operated radio nets for command and control of combat, combat support, and combat service support operations among ground, sea, and air forces.

Source: from Federal Standard 1037C and from MIL-STD-188