(Carrier Sense Multiple Access with Collision Avoidance/Detection)- is a MAC protocol where nodes try to sense the existence of other transmissions/traffic before sending out transmissions itself. This is a technique used for shared mediums, such as RF cellular networks. Subsequent variations include improvements:
where a node immediately terminates any transmission once collision is detected, speeding up the re transmission.
Collision detection – where if a medium is busy with a transmission, it postpones the transmission at a random Collision avoidance – interval, greatly reducing the chances of simultaneous transmission.