Carrier Sense Multiple Access/Collision Detect is an improvement over ALOHA as it restricts transmitting 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.


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, which deals with collisions after their occurrence. It prevents collisions before their occurrence.

Difference between CSMA/CD and CSMA/CA:

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.