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Improving the Performance of IEEE 802.11e using A Dynamic Adaptation Approach

Yasser A. Dahab, Hesham N. El Mahdy, Iman A. Saroit


Providing Quality of Service (QoS) for real time applications in mobile Ad hoc networks is a challenging task, due to the characteristics of the wireless links and networks. These Characteristics include: dynamic nature, infrastructure less architecture, and time varying unstable links and topology.

Features as: low cost, ease of deployment, increased coverage, and enhanced capacity make IEEE 802.11 distributed coordination function (DCF) more popular in wireless applications. However, DCF is unsuitable for real time applications which have strict demands on QoS. IEEE 802.11e Medium Access Control (MAC) was   introduced to support QoS in Wireless Local Area Networks (WLANs).

Many researches have been proposed to enhance IEEE 802.11e such as Gentle Decrease, and SCW.

In this paper, we propose a new approach called “Dynamic Adaptive Approach for enhancement of EDCA” (DAA_EDCA). The proposed approach was inspired from the Gentle Decrease Scheme.


Ad hoc Networks, MANET, QoS, DCF, EDCA, Gentle Decrease, SCW, DAA-EDCA

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C. Siva Ram Murthy and B.S. Manoj, “Ad hoc wireless Networks, Architectures and protocols”, Prentice Hall Communications Engineering and Emerging Techno, 2004.

IEEE-SA Standards Board Std. 802.11e Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Amendment 8: Medium Access Method MAC) Quality of Service Enhancements, Nov 2005.

IEEE 802.11. Standard 802.11: Wireless LAN Medium Access Control (MAC) and Physical layer (PHY) Specifications. 1999.

G. Bianchi, I. Tinnirello, and L. Scalia, “Understanding 802.11e Contention-Based Prioritization Mechanisms and Their Coexistence with Legacy 802.11 Stations”, IEEE Network, vol. 19, no. 4, 2005, pp. 28-34.

IEEE 802.11e WG. Draft supplement to Part 11: Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications: MAC Enhancements for Quality of Service (QoS), IEEE Std. 802.11e/D9.0, August 2004.

H. Zhu, et al., “A survey of quality of service in IEEE 802.11 networks,” IEEE Wireless Communications, Vol. 11, 2004, pp. 6-14.

X. Chen et al., “Supporting QoS in IEEE 802.11e wireless LANs,” IEEE Trans. Wireless Commun., vol. 5, no. 8, Aug. 2006, pp. 2217–27.

R.Moraes, P. Portugal, F. Vasques, “Simulation Analysis of the IEEE 802.11e EDCA Protocol for an Industrially-Relevant Real-Time Communication Scenario,” IEEE ETFA’06, Prague, Czech Republic, Sept. 20-22, 2006.

L. Romdhani, Q. Ni, T. Turletti, “Adaptive EDCF: Enhanced Service Differentiation for IEEE 802.11 802.11 Wireless Ad-Hoc Networks,” IEEE WCNC’03, New Orleans, USA, vol. 2, March 2003, pp. 1373-1378.

C. Wang, B. Li, and L. Li, “A New Collision Resolution Mechanism to Enhance the Performance of IEEE 802.11 DCF,” IEEE Transactions on Vehicular Technology, vol. 53, no. 4, July 2004, pp. 1235–1246.

A.Nafaa, A.Ksentini and A.Mehaoua “SCW: sliding contention window for efficient service differentiation in IEEE 802.11 networks,” Wireless Communications and Networking Conference, IEEE Vol. 3, 2005, pp. 1626 -1631.

S. Wiethoelter and C. Hoene, “Design and Verification of an IEEE 802.11e EDCF Simulation Model in ns-2.26,” Technical Report TKN-03-019, Telecommunication Networks Group, Technische Universitaet Berlin, November 2003.

S. Wiethoelter and C. Hoene, “An IEEE 802.11e EDCF and CFB Simulation Model for ns2”. Available: http://www.tkn.tuberlinde/research/802.11e_ns2/

Network Simulator ns-2. Available:

Frank Roijers, Hans van den Berg and Michel Mandjes, “Performance analysis of differentiated resource-sharing in a wireless ad-hoc networks,” Performance Evaluation, Volume 67, Issue 7, July 2010, pp. 528-547.

Coskun Cetinkaya, “Service differentiation mechanisms for WLANS,” Ad Hoc Networks, Volume 8, Issue 1, January 2010, pp. 46-62.

Gennaro Boggia, Pietro Camarda, Luigi Alfredo Grieco and Giuseppe Piro, “Extended EDCA for delay guarantees in wireless local area networks”, Pervasive and Mobile Computing, Volume 5, Issue 5, October 2009, pp. 402-418.


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