Research Article Open Access

History Based Contention Window Control in IEEE 802.11 MAC Protocol in Error Prone Channel

Ali Balador1, Ali Movaghar1 and Sam Jabbehdari1
  • 1 ,
Journal of Computer Science
Volume 6 No. 2, 2010, 205-209


Submitted On: 8 January 2010 Published On: 28 July 2010

How to Cite: Balador, A., Movaghar, A. & Jabbehdari, S. (2010). History Based Contention Window Control in IEEE 802.11 MAC Protocol in Error Prone Channel. Journal of Computer Science, 6(2), 205-209.


Problem statement: IEEE 802.11 Medium Access Control (MAC) protocol is one of the most implemented protocols in this network. The IEEE 802.11 controls the access to the share wireless channel within competing stations. The IEEE 802.11 DCF doubles the Contention Window (CW) size for decreasing the collision within contending stations and to improve the network performances but it is not good for error prone channel because the sudden CW rest to CWmin may cause several collisions. Approach: The research to date has tended to focus on the current number of active stations that needs complex computations. A novel backoff algorithm is presented that optimizes the CW size with take into account the history of packet lost. Results: Finally, we compare the HBCWC with IEEE 802.11 DCF. The simulation results have shown 24.14, 56.71 and 25.33% improvement in Packet Delivery Ratio (PDR), average end to end delay and throughput compared to the IEEE 802.11 DCF. Conclusion: This study showed that monitoring the last three channel status achieve better delay and throughput that can be used for multimedia communications.

  • 6 Citations



  • IEEE 802.11
  • MAC protocol
  • back off algorithm
  • contention window
  • error prone channel