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Journal of Computer Systems, Networks, and Communications
Volume 2010, Article ID 856724, 12 pages
Research Article

A Novel Prioritization Scheme to Improve QoS in IEEE 802.11e Networks

The Electrical Engineering Department, K. N. Toosi University of Technology, Seyed khandan, Dr. Shariati Ave, P.O. Box 16315-1355, Tehran, Iran

Received 8 October 2009; Revised 6 March 2010; Accepted 21 March 2010

Academic Editor: Sghaier Guizani

Copyright © 2010 Navid Tadayon et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


IEEE 802.11 WLAN utilizes a distributed function at its MAC layer, namely, DCF to access the wireless medium. Due to its distributed nature, DCF is able to guarantee working stability in a wireless medium while maintaining the assembling and maintenance cost in a low level. However, DCF is inefficient in dealing with real-time traffics due to its incapability on providing QoS. IEEE 802.11e was introduced as a supplementary standard to cope with this problem. This standard introduces an Enhanced Distributed Coordination Function (EDCF) that works based on diff-Serve model and can serve multiple classes of traffics (by using different prioritizations schemes). With the emergence of new time-sensitive applications, EDCF has proved to be yet inefficient in dealing with these kinds of traffics because it could not provide network with well-differentiated QoS. In this study, we propose a novel prioritization scheme to improve QoS level in IEEE 802.11e network. In this scheme, we replace Uniform PDF with Gamma PDF, which has salient differentiating properties. We investigate the suitability and superiority of this scheme on furnishing network with well-differentiated QoS using probabilistic analysis. We strengthen our claims by extensive simulation runs.