Question

Consider a scenario with three clients: A is currently sending a data package to B while C also wants to send a data package to B. Suppose that C senses the channel status at the beginning of A’s transmission. Please draw the data transmission process of this scenario in CSMA/CA under 802.11 DCF.

Answer 1

Multiple Access with Collision Avoidance (CSMA-CA) Procedure: Instead of sending packets control frames are exchanged.802.11 standard for WLAN defines a distributed coordination function (DCF) for sharing access to the medium based on the CSMA/CA protocol .

C listens to the channel before transmission to determine whether some one else is transmitting A sends an acknowledge packet (ACK) to B.

If an ACK is not received, the packet is considered lost and a retransmission is arranged

scenario:

A is currently sending a data package to B.

C also wants to send a data package to B.

C senses the channel status at the beginning of A’s transmission..

Just an example how does this work actually.