CSMA/CARP

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In computer networking, Carrier Sense Multiple Access With Collision Avoidance and Resolution using Priorities (CSMA/CARP) is a network control protocol used by the IEEE 802.11 protocol.

CSMA/CARP is similar in nature to the CSMA/CD technology used in Ethernet networks, but CSMA/CARP provides no detection of network collisions. Instead of detection network collisions CSMA/CARP attempts to avoid collisions by using a system of transmission priorities.

When a station wants to transmit on a CSMA/CARP network it first listens for network traffic and if the medium is clear instead of immediately transmitting as a station would in CSMA/CD it waits a predefined amount of time. This waiting period is called the interframe space (IFS) and it varies by the type of data being transmitted. High priority data will transmit almost immediately where as lower priority data such as polling will have a longer IFS. This system allows CSMA/CARP to avoid many collisions that would occur if it was not used.