A Study on the Binary Exponential Backoff in Noisy and Heterogeneous Environment

  • Khoder Shamy
  • Chadi Assi
  • Lei Guang
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4864)

Abstract

Recently, some proposals have suggested that maintaining the same contention window (CW), or reducing it, for nodes suffering packet losses, due to channel transmission impairments, is effective in increasing the performance of the IEEE 802.11 in noisy environment. Our study presented inhere will prove analytically and via simulations that this should not be necessarily the case. To facilitate our analysis, we consider two binary exponential backoff (BEB) algorithms in our study: a standard BEB where a host increases its CW upon every packet loss (collision or transmission error) and another access method with a capability to differentiate between the type of losses; here, a host experiencing a loss will increase its CW only after a collision and remain in the same backoff stage otherwise. We show that the second access procedure outperforms the standard BEB when the network is lightly loaded. However, in a congested network, this quick recovery property results in intensifying the collisions among contending nodes and hence yields a poor system performance. We propose a hybrid method that takes advantage of both access methods to achieve better throughput under various network loads.

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References

  1. 1.
    Lopez-Aguilera, E., Heusse, M., Rousseau, F., Duda, A., Casademont, J.: Evaluating Wireless LAN Access Methods in Presence of Transmission Errors. In: IEEE INFOCOM (2006)Google Scholar
  2. 2.
    Chatzimisios, P., Boucavalas, A.C., Vistas, V.: Performance Analysis of IEEE 802.11 DCF in Presence of Transmission Errors. In: IEEE ICC (June 2004)Google Scholar
  3. 3.
    Malone, D., Clifford, P., Leith, D.J.: MAC Layer Channel Quality Measurement in 802.11. IEEE Comm. Letters 11(2) (February 2007)Google Scholar
  4. 4.
    Aguayo, D., Bicket, J., Biswa, S., Judd, G., Morris, R.: Link Level Measurements from an 802.11b Mesh Network. In: Proc. of ACM SIGCOMM, Boston, USA (2004)Google Scholar
  5. 5.
    Nadeem, T., Agrawala, A.: IEEE 802.11 DCF Enhancements for Noisy Environments. In: Proc. of IEEE PIMRC (September 2004)Google Scholar
  6. 6.
    Heusse, M., Rousseau, F., Guillier, R., Duda, A.: Idle Sense: An Optimal Access Method for High Throughput and Fairness in Rate Diverse Wireless LANs. In: Proc. of ACM SIGCOMM (August 2005)Google Scholar
  7. 7.
    SNT, QualNet Simlator, http://www.scalable-networks.com/
  8. 8.
    Qiao, D., Choi, S.: Goodput Enhancement of IEEE 802.11a Wireless LAN via Link Adaptation. In: Proc. IEEE ICC, Finland (2001)Google Scholar
  9. 9.
    Pang, Q., Liew, S.C., Leung, V.C.M.: Design of an Effective Loss-Distinguishable MAC Protocol for 802.11 WLAN. IEEE Comm. Letters 9(9) (September 2005)Google Scholar
  10. 10.
    Bianchi, G.: Performance Analysis of the IEEE 802.11 Distributed Coordination Function. IEEE JSAC 18(3), 535–547 (2000)Google Scholar
  11. 11.
    Medepalli, K., Tobagi, F.A.: Throughput Analysis of IEEE 802.11 Wireless LANs using an Average Cycle Time Approach. In: Proc. of GLOBECOM (2005)Google Scholar
  12. 12.
    Medepalli, K., Tobagi, F.A.: On Optimization of CSMA/CA based Wireless LANs: Part I − Impact of Exponential Backoff. In: Proc. of ICC (June 2006)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2007

Authors and Affiliations

  • Khoder Shamy
    • 1
  • Chadi Assi
    • 1
  • Lei Guang
    • 1
  1. 1.Concordia University, Montréal, Québec, H3G 1M8Canada

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