The Basic Access Method: CSMA/CA

The Distributed Coordination Function  essentially  Carrier a Sense Multiplying  Access with Collision Avoidance  mechanism (also known as CSMA/CA). CSMA protocols are one of the most known protocols in the industry, where the most common one is Ethernet which refers to CSMA/CD protocol (CD standing for Collision Detection).

The CSMA protocol works as  A station that transmit senses to the medium if the medium is not responding or some other station is transmitting then the medium will continue transmission at a later stage if the medium is sensed free then the station will accept transmission

The following protocol are very effective when the medium is not heavily saturated, because it allows stations to transmit with minimum delay, but there is always a chance that there is another stations transmitting at the same time because of another stations sensed the medium free and decided to transmit (collision).

In this case the collision must be identified so that the MAC layer could retransmit the packet individually and not by the upper layers which may cause significant delay. The Ethernet collision is identified by transmitting stations that goes thought the retransmission stage based on the exponential random backoff algorithm.

These Collision Detecting mechanism are good for wire LAN and cannot be used on WIreless LAN.

So how do we over come this problems.....