CSMA (Carrier Sense Multiple Access) technology is used in LAN devices to prevent collision. Collision happens when devices connected in a network of collision domain transmits at the same time which will cause interruption of data flow between devices.
Carrier Sense enables the network devices to listen for traffic and if the channel is free, transmission of data is allowed.
Multiple Access allows multiple devices to connect and transmit without collision on the network device.
Types of CSMA
CSMA/CD (Carrier Sense Multiple Access with Collision Detection)
CSMA/CD is reactive collision prevention technology used in switches. This prevents collision after a collision is detected in the switch.
Collision Detection detects the collision in the switch and sends a jam signal to all devices to stop transmitting data for a wait time to avoid collision. After the wait time, the device can transmit the data.
CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance)
CSMA/CA is pro-active collision prevention technology used in Wireless Access Point. This prevents collision proactively.
Collision Avoidance is done by listening to the wireless network and then allowing the wireless devices to transmit when the wireless channel is free to transmit.