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 transmission medium, such as an electrical bus, or a band of the electromagnetic spectrum.
"Carrier Sense" describes the fact that a transmitter uses feedback from a receiver that detects 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 station waits for the transmission in progress to finish before initiating its own transmission. In other words, CSMA is based on the principle "sense before transmit" or "listen before talk".
"Multiple Access" describes the fact that multiple stations send and receive on the medium. Transmissions by one node are generally received by all other stations using the medium.
Read more about Carrier Sense Multiple Access: CSMA Access Modes
Famous quotes containing the words carrier, sense, multiple and/or access:
“It is the corpse of the bourgeoisie that separates us. With us, it is that class that is the carrier of the chromosome of banality.”
—Jean Baudrillard (b. 1929)
“Sinclair Lewis is the perfect example of the false sense of time of the newspaper world.... [ellipsis in source] He was always dominated by an artificial time when he wrote Main Street.... He did not create actual human beings at any time. That is what makes it newspaper. Sinclair Lewis is the typical newspaperman and everything he says is newspaper. The difference between a thinker and a newspaperman is that a thinker enters right into things, a newspaperman is superficial.”
—Gertrude Stein (1874–1946)
“Combining paid employment with marriage and motherhood creates safeguards for emotional well-being. Nothing is certain in life, but generally the chances of happiness are greater if one has multiple areas of interest and involvement. To juggle is to diminish the risk of depression, anxiety, and unhappiness.”
—Faye J. Crosby (20th century)
“In the greatest confusion there is still an open channel to the soul. It may be difficult to find because by midlife it is overgrown, and some of the wildest thickets that surround it grow out of what we describe as our education. But the channel is always there, and it is our business to keep it open, to have access to the deepest part of ourselves.”
—Saul Bellow (b. 1915)