# Decentralised learning MACs for collision-free access in WLANs

- 667 Downloads
- 31 Citations

## Abstract

By combining the features of CSMA and TDMA, fully decentralised WLAN MAC schemes have recently been proposed that converge to collision-free schedules. In this paper we describe a MAC with optimal long-run throughput that is almost decentralised. We then design two schemes that are practically realisable, decentralised approximations of this optimal scheme and operate with different amounts of sensing information. We achieve this by (1) introducing learning algorithms that can substantially speed up convergence to collision free operation; (2) developing a decentralised schedule length adaptation scheme that provides long-run fair (uniform) access to the medium while maintaining collision-free access for arbitrary numbers of stations.

## Keywords

Learning MAC Collision-free MACs Convergence time Schedule length adaptation## Notes

### Acknowledgments

Work supported by SFI Grant 07/SK/I1216a, the European Community’s 7th Framework Programme (FP7-ICT-2009-5) under grant agreement n. 257263 (FLAVIA project) and HEA's Network Maths Grant.

## References

- 1.Asmussen, S. (2003).
*Applied Probability and Queues*, second edn., Berlin: Springer.zbMATHGoogle Scholar - 2.Barcelo, J., Bellalta, B., Cano, C. & Oliver, M. (2008).
*Learning-BEB: Avoiding Collisions in WLAN*. Stuttgart: Eunice Summer School.Google Scholar - 3.Berger-Sabbatel, G., Duda, A., Gaudoin, O., Heusse, M. & Rousseau, F. (2004). Fairness and its impact on delay in 802.11 networks. In:
*IEEE GLOBECOM*.Google Scholar - 4.Bianchi, G. (2000). Performance analysis of the IEEE 802.11 distributed coordination function.
*IEEE Journal on Selected Areas in Communications, 18*(3), 535–547.CrossRefGoogle Scholar - 5.Busch, C., Magdon-Ismail, M., Sivrikaya, F. & Yener, B. (2004). Contention-free MAC protocols for wireless sensor networks.
*Lecture Notes in Computer Science, 3274*, 245–259.CrossRefGoogle Scholar - 6.Chen, C., Liang, G. & Vaidya, N. (2010).
*OCP: Opportunistic carrier prediction for wireless networks*. In: IEEE conference on mobile adhoc and sensor systems (MASS), (pp. 1–10). doi: 10.1109/MASS.2010.5663974. - 7.Chen, C., Seo, E., Kim, H. & Luo, H. (2006). Self-learning collision avoidance for wireless networks. In
*Proceedings of IEEE INFOCOM*.Google Scholar - 8.Chen, Y. & Wang, H. (2007). Ordered CSMA: A collision-free MAC protocol for underwater acoustic networks.
*Oceans*, 1–6.Google Scholar - 9.Duffy, K. R., O’Connell, N. & Sapozhnikov, A. (2008). Complexity analysis of a decentralised graph colouring algorithm.
*Information Processing Letters, 107*(2), 60–63.MathSciNetzbMATHCrossRefGoogle Scholar - 10.Heusse, M., Rousseau, F., Guillier, R. & Duda, A. (2005). Idle sense: An optimal access method for high throughput and fairness in rate diverse wireless lans.
*ACM SIGCOMM Computer Communication Review, 35*(4), 121–132.CrossRefGoogle Scholar - 11.
*IEEE: Wireless LAN medium access control (MAC) and physical layer (PHY) specifications: Medium access control (MAC) enhancements for quality of service (QoS)*, IEEE std 802.11e edn.Google Scholar - 12.Jain, R., Chiu, D. & Hawe, W. (1984).
*A quantitative measure of fairness and discrimination for resource allocation in shared computer systems*. DEC Technical Report 301.Google Scholar - 13.Koksal, C., Kassab, H. & Balakrishnan, H. (2000). An analysis of short-term fairness in wireless media access protocols (poster session). In
*Proceedings of the 2000 ACM SIGMETRICS international conference on measurement and modeling of computer systems*, (pp. 118–119). NY, USA: ACM New York.Google Scholar - 14.Lee, J. & J. Walrand (2008). Design and analysis of an asynchronous zero collision MAC protocol. Arxiv preprint 0806.3542v1 [cs.NI].Google Scholar
- 15.Leith, D. & Clifford, P. (2006). A self-managed distributed channel selection algorithm for WLANs. In
*Proceedings of international symposium on modeling and optimization in mobile, ad hoc and wireless networks*, (pp. 1–9).Google Scholar - 16.Malone, D., Duffy, K. & Leith, D. (2007). Modeling the 802.11 distributed coordination function in nonsaturated heterogeneous conditions.
*IEEE/ACM Transactions on Networking, 15*(1), 159–172.CrossRefGoogle Scholar - 17.Narendra, K. & Thathachar, M. A. L. (1989).
*Learning automata: An introduction*. New Jersey: Prentice Hall.Google Scholar - 18.Ni, Q., Li, T., Turletti, T. & Xiao, Y. (2005). Saturation throughput analysis of error-prone 802.11 wireless networks.
*Wireless Communications and Mobile Computing, 5*(8), 945–956.CrossRefGoogle Scholar - 19.Rhee, I., Warrier, A., Aia, M., Min, J. & Sichitiu, M. (2008). Z-MAC: A hybrid MAC for wireless sensor networks.
*IEEE/ACM Transactions on Networking (TON), 16*(3), 511–524.CrossRefGoogle Scholar - 20.Starzetz, P., Heusse, M., Rousseau, F. & Duda, A. (2009). Hashing backoff: A collision-free wireless access method. In
*Proceedings of IFIP Networking, vol. 5550*, (pp. 11–15). Springer.Google Scholar - 21.Wang, P. & Zhuang, W. (2008).
*A collision-free MAC scheme for multimedia wireless mesh backbone*. In IEEE International Conference on Communications, 2008. ICC’08, (pp. 4708–4712).Google Scholar - 22.Yi, Y., de Veciana, G. & Shakkottai, S. (2010). Mac scheduling with low overheads by learning neighborhood contention patterns.
*IEEE/ACM Transactions on Networking, 18*(5), 1637–1650.CrossRefGoogle Scholar - 23.Yong, H., Ruxi, Y., Jie, S. & Weibo, G. (2009).
*Semi-random backoff: Towards resource reservation for channel access in wireless LANs*. In: IEEE International Conference on Network Protocols (ICNP).Google Scholar