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:
“When toddlers are unable to speak about urgent matters, they must resort to crying or screaming. This happens even with adults. The voice is the carrier of emotion, and when speech fails us, we need to cry out in whatever form we can to convey our meaning. Often, what passes for negativism is really the toddler’s desperate effort to make herself understood.”
—Alicia F. Lieberman (20th century)
“Art should exhilarate, and throw down the walls of circumstance on every side, awakening in the beholder the same sense of universal relation and power which the work evinced in the artist, and its highest effect is to make new artists.”
—Ralph Waldo Emerson (1803–1882)
“... the generation of the 20’s was truly secular in that it still knew its theology and its varieties of religious experience. We are post-secular, inventing new faiths, without any sense of organizing truths. The truths we accept are so multiple that honesty becomes little more than a strategy by which you manage your tendencies toward duplicity.”
—Ann Douglas (b. 1942)
“Lesbian existence comprises both the breaking of a taboo and the rejection of a compulsory way of life. It is also a direct or indirect attack on the male right of access to women.”
—Adrienne Rich (b. 1929)