Carrier sense multiple access
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It has been suggested that this article or section be merged with Carrier_sense_multiple_access_with_collision_avoidance. (Discuss) |
Carrier Sense Multiple Access (CSMA) is a probabilistic Media Access Control (MAC) protocol in which a node verifies the absence of other traffic before transmitting on a shared physical medium, such as an electrical bus, or a band of electromagnetic spectrum.
"Carrier Sense" describes the fact that a transmitter listens for a carrier wave before trying to send. That is, it tries to detect the presence of an encoded signal from another station before attempting to transmit. If a carrier is sensed, the node waits for the transmission in progress to finish before initiating its own transmission.
"Multiple Access" describes the fact that multiple nodes send and receive on the medium. Transmissions by one node are generally received by all other nodes using the medium.
