This paper presents an adaptive backoff algorithm for the contention-based Distributed Coordination Function (DCF) of the IEEE 802.11 standard. Relying on on-line measurements of the number of sources, the algorithm, called Adaptive BEB, judiciously sets the size of the minimal contention window to adapt to the congestion level in the shared medium. The paper also provides an extension to Adaptive BEB for enhancing its performance over noisy channels. In this extension, a simple EWMA filter is used to derive a Packet Error Rate estimator. The performance evaluation of our proposal is addressed via simulations.


DCF mechanism optimal adaptation performance evaluation noise 


  1. 1.
    Bianchi, G.: Performance analysis of the IEEE 802.11 distributed coordination function. IEEE Journal on Selected Areas in Communications 18(3), 535–547 (2000)MathSciNetCrossRefGoogle Scholar
  2. 2.
    Cali, F., Conti, M., Gregori, E.: Dynamic tuning of the IEEE 802.11 protocol to achieve a theoretical throughput limit. IEEE/ACM Trans. on Networking 8(6), 785–799 (2000)CrossRefGoogle Scholar
  3. 3.
    Cali, F., Conti, M., Gregori, E.: IEEE 802.11 protocol: design and performance evaluation of an adaptive backoff mechanism. IEEE J. on Sel. Areas in Comm. 18(9), 1774–1786 (2000)CrossRefGoogle Scholar
  4. 4.
    IEEE Std. 802.11b, Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specification (1999)Google Scholar
  5. 5.
    Bianchi, G., Fratta, L., Oliveri, M.: Performance evaluation and enhancement of the CSMA/CA MAC protocol for 802.11 wireless LANs. In: Proc. of PIMRC 1996 (1996)Google Scholar
  6. 6.
    Bononi, L., Conti, M., Gregori, E.: Runtime optimization of IEEE 802.11 wireless LANs performance. IEEE Transactions on Parallel and Distributed Systems 15(1), 66–80 (2004)CrossRefGoogle Scholar
  7. 7.
    Aad, I., Ni, Q., Barakat, C., Turletti, T.: Enhancing IEEE 802.11 MAC in congested environments. In: Proc. of IEEE ASWN 2004, Boston, Massachusetts (2004)Google Scholar
  8. 8.
    Galtier, J.: Optimizing the IEEE 802.11b performance using slow congestion window decrease. In: Proc. of 16th ITC Specialist Seminar, Anvers, Belgique (2004)Google Scholar
  9. 9.
    Nadeem, T., Agrawala, A.: IEEE 802.11 DCF enhancements for noisy environments. In: Proc. of PIMRC 2004, Barcelona, Spain (2004)Google Scholar
  10. 10.
    Bianchi, G., Tinnirello, I.: Kalman filter estimation of the number of competing terminals in an IEEE 802.11 network. In: Proc. of IEEE INFOCOM 2003 (2003)Google Scholar
  11. 11.
    Bertsekas, D., Gallager, R.: Data Network. Prentice Hall, Englewood Cliffs (1992)zbMATHGoogle Scholar
  12. 12.
    The network simulator, version 2.28 (2005),
  13. 13.
    Jain, R., Hawe, W., Chiu, D.: Quantitative measure of fairness and discrimination for resource allocation in shared computer systems. Technical Report DEC-TR-301, DEC (1984)Google Scholar
  14. 14.
    Koksal, C.E., Kassab, H., Balakrishnan, H.: An analysis of short-term fairness in wireless media access protocols (extended abstract). Perf. Eval. Rev. 28(1), 118–119 (2000)CrossRefGoogle Scholar

Copyright information

© IFIP International Federation for Information Processing 2006

Authors and Affiliations

  • Mouhamad Ibrahim
    • 1
  • Sara Alouf
    • 1
  1. 1.INRIASophia AntipolisFrance

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