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Minimizing contention through cooperation between densely deployed wireless LANs

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Abstract

Contention at shared medium access may seriously degrade the performance of a CSMA/CA-based wireless LAN. Where wireless LANs from different operators are densely deployed, controlling contention merely by intelligent selection of installation sites and assignment of operating channels becomes challenging at least. We show that cooperation between these networks may lead to a significant reduction in overall contention. To this end, we present a mathematical programming formulation of the minimal inter-domain contention problem and derive theoretical lower bounds for it. We show how to practically determine exact solutions for small problem instances and near-optimal solutions for larger scenarios. Most importantly, we introduce a distributed algorithm and protocol that allows access points to self-coordinate in order to minimize contention and relies solely on information about each access point’s immediate neighborhood. In experiments, we show that cooperation between domains may more than halve contention even in only moderately dense deployments. Furthermore, we demonstrate that our distributed algorithm may reduce contention by 19% compared to cooperation using standard WLAN mechanisms. Contrary to common belief, our findings suggest that in dense deployments switching off selected access points may be more effective in decreasing contention than using them for load balancing.

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References

  1. FON. http://www.fon.com (last access: 2007-09-01).

  2. lp_solve. http://tech.groups.yahoo.com/group/lp_solve (last access: 2007-09-01).

  3. NYCwireless. http://www.nycwireless.net (last access: 2007-09-01).

  4. AutoCell—The Self-Organizing WLAN (2003). White paper, Propagate Networks. http://www.propagatenet.com/resources/ docs/whitepaper_autocell.pdf (last access: 2006-02-01).

  5. WS5100 Wireless Switch Reviewer’s Guide (2005). Product brochure, symbol. ftp://symstore.longisland.com/Symstore/pdf/ wireless/WS5100ReviewersGuide.pdf (last access: 2007-09-01).

  6. Akella, A., Judd, G., Seshan, S., & Steenkiste, P. (2005). Self-management in chaotic wireless deployments. In 11th International Conference on Mobile Computing and Networking (MOBICOM ’05). Cologne, Germany.

  7. Amaldi, E., Capone, A., Cesana, M., & Malucelli, F. (2004). Optimizing WLAN radio coverage. In IEEE International Conference on Communications (ICC 2004) (pp. 180–184). Paris, France.

  8. Bejerano, Y., Han, S.-J., & Li, L. (2004). Fairness and load balancing in wireless LANs using association control. In Proceedings of the 10th International Conference on Mobile Computing and Networking (pp. 315–329). Philadelphia, PA, USA.

  9. Goldberg, D. A. (1989). Genetic algorithms in search, optimization, and machine learning. Addison-Wesley.

  10. Hills, A., & Friday, B. (2004). Radio resource management in␣wireless LANs. IEEE Communications Magazine, 42(10), 9–14.

    Article  Google Scholar 

  11. ITU-R P.1238-2 (2001). Propagation data and prediction methods for the planning of radio communication systems and radio local␣area networks in the frequency range of 900 MHz to 100 GHz.

  12. Kumar, A., & Kumar, V. (2005). Optimal Association of Stations and APs in an IEEE 802.11 WLAN. In Proceedings of the National Conference on Communications (NCC) (pp. 1–5). Kharagpur, India.

  13. Lee, Y., Kim, K., & Choi, Y. (2002). Optimization of AP placement and channel assignment in wireless LANs. In IEEE Conference on Local Computer Networks (LCN 2002).

  14. Leung, K. K., & Kim, B.-J. (2003). Frequency assignment for IEEE 802.11 wireless networks. In 58th IEEE Vehicular Technology Conference (VTC 2003 Fall) (pp. 1422–1426). IEEE.

  15. Ling, X., & Yeung, K. L. (2005). Joint access point placement and channel assignment for 802.11 wireless LANs. In IEEE Wireless Communications and Networking Conference (WCNC 2005).

  16. Matsunaga, Y., & Katz, R. H. (2004). Inter-domain radio resource management for wireless LANs. In IEEE Wireless Communications and Networking Conference (WCNC 2004) (pp. 2183–2188). Atlanta, Georgia, USA.

  17. Mishra, A., Banerjee, S., & Arbaugh, W. (2005). Weighted coloring based channel assignment in WLANs. ACM SIGMOBILE Mobile Computing and Communications Review (MC2R), 9(3), 19–31.

    Article  Google Scholar 

  18. Wang, Y., Cuthbert, L., & Bigham, J. (2004). Intelligent radio resource management for IEEE 802.11 WLAN. In IEEE Wireless Communications and Networking Conference (WCNC 2004) (pp. 1365–1370). Atlanta, Georgia USA.

  19. Zdarsky, F. A., Martinovic, I., & Schmitt, J. B. (2005). On lower bounds for MAC layer contention in CSMA/CA-based wireless networks. In 3rd ACM/SIGMOBILE International Workshop on Foundations of Mobile Computing (DIALM-POMC’05) (pp. 8–16). Cologne, Germany.

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Acknowledgements

The authors would like to thank the anonymous reviewers and Augustin Chaintreau for their comments that helped to improve the quality of this paper.

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Correspondence to Frank A. Zdarsky.

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Zdarsky, F.A., Martinovic, I. & Schmitt, J.B. Minimizing contention through cooperation between densely deployed wireless LANs. Wireless Netw 15, 741–754 (2009). https://doi.org/10.1007/s11276-007-0072-3

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  • DOI: https://doi.org/10.1007/s11276-007-0072-3

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