State about CSMA/CA

It belongs to a class of protocols known as multiple access methods. CSMA/CA  stands  for:  Carrier  Sense  Multiple  Access  with  Collision Avoidance.  In  CSMA,  a  station  willing to  transmit  has  to  first  listen  to  channel for a predetermined amount of time so as to check for any activity on channel.  If  channel  is  sensed  "idle"  then  station  is  permitted  to transmit.  If  channel  is  sensed  as  "busy"  station  has  to  defer  its transmission.  This  is  essence  of  both  CSMA/CD  and  CSMA/CA.  In CSMA/CA  (Local  Talk),  once  channel  is  clear,  a  station  transmits a  signal telling all other stations not to transmit, and then sends its packet. In Ethernet 802.3, station continues to wait for a time, and checks to see if channelis still free. If it is free, station transmits, and waits for an acknowledgment signal that packet was received.