Carrier Sense Multiple Access/Collision Detect is an improvement over ALOHA as it restricts to transmit when the channel is busy. But if two stations sense the channel simultaneously and feel it idle then both of them transmit frames resulting in a collision.

Contention Period


Carrier Sense Multiple Access with Collision Avoidance is a network protocol for carrier transmission that operates in the MAC layer. In contrast to CSMA/CD, that deals with collisions after their occurrence. It prevents collisions prior to their occurrence.

We can comparison between CSMA/CD and CSMA/CA is given below:

1. CSMA CD takes effect after a collision1. CSMA CA takes effect before a collision
2. CSMA/CD is part of the IEEE 802.3 standard2. CSMA/CA is part of the IEEE 802.11 standard
3. CSMA/CD reduces the recovery time3. CSMA/ CA minimizes the possibility of collision
4. CSMA/CD is more efficient than CSMA/CA4. CSMA/CA is less efficiency than CSMA/CD
5. CSMA CD is typically used in wired networks.5. CSMA/CA is used in wireless networks.