CSMA/CD is used in wired LANs, CSMA means that the computers on the network sense the medium if the medium is idle, the computer transmits otherwise it defers sending.CD refers to collision detection. I don’t want to write about CD because its not related to my Question.
Now in case of wireless LANs we use CSMA/CA , here CSMA refers to carrier sensing , the Question is how carrier sensing is done in case of wireless LANs? the collision avoidance is done by sending the control message to the intended receipient.