Carrier-sense multiple access with collision avoidance

Carrier-sense multiple access with collision avoidance (CSMA/CA) in computer networking, is a network multiple access method in which carrier sensing is used, but nodes attempt to avoid collisions by beginning transmission only after the channel is sensed to be "idle".

Although CSMA/CA has been used in a variety of wired communication systems, it is particularly beneficial in a wireless LAN due to a common problem of multiple stations being able to see the Access Point, but not each other.

This is due to differences in transmit power, and receive sensitivity, as well as distance, and location with respect to the AP.

[6] Devices utilizing 802.11 based standards can enjoy the benefits of collision avoidance (RTS / CTS handshake, also Point coordination function), although they do not do so by default.

Implementation of RTS/CTS helps to partially solve the hidden node problem that is often found in wireless networking.