because in a wireless system, collision detection is not possible and there is no way to do error correction so collision avoidance is the only method
CSMA/CD: Carrier Sense Multiple Access / Collision Detection.
The acronym CSMA CD stands for Carrier Sense Multiple Access with Collision Detection. CSMA CD is a set of rules determining how network devices respond when two devices attempt to use a data channel simultaneously.
10BaseT
Because CSMA/CD does not prevent Hidden terminal problem. so it is onlly applicable in Wired networks.
*** In CSMA/CD it detects that a collision take place and resend the frame that was send. On a wirless network losing bandwidth along with time to detect that a collision took place was not acceptable , so CSMA/CA was utilized. ** CSMA/CD can achieve above 70% efficiency under heavy loads compared to CSMA/CA that can only achieve up to 30% efficiency under heavy loads. CSMA/CA network: A network in which the medium access control protocol requires carrier sense and where a station always starts transmission by sending a jam signal; if there is no collision with jam signals from other stations, it begins sending data; otherwise, it stops transmission and then tries again later. CSMA/CD network: A bus network in which the medium access control protocol requires carrier sense and in which exception conditions caused by collision are resolved by retransmission
Csma/cd
IP, appletalk, token ring, CSMA/CD, CSMA/CA
Devices listen to the media and transmit data only when they cannot detect another signal on the media. All devices on the media can hear all communications When a collision occurs, all devices stop transmitting for a randomly generated period of time.
Collisions can decrease network performance.
Csma/cd
This is the Algorithm use by CSMA/CD as a wait period to allow other devices on the network to access the media.
Most star topologies use CSMA/CD for a Local Area Network. WANs and MANs are different and use completely different access methods.