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Guaranteed Services for Multimedia Applications over 802.11e Wireless Local Area Networks.  

This Research project investigates QoS guarantees for Multimedia Applications over an IEEE 802.11e wireless LAN. QoS guarantee mechanisms that are of interest to this research are mainly scheduling and admission control algorithms. We have designed several algorithms that improve the performance of 802.11e networks and provide QoS to Multimedia application. These methods are :

1. Distributed Adaptively Configured EDCA (DACE) is an algorithm that adaptively configures EDCA parameters and acheives higher throughput than the standard EDCA. DACE is a contention based mechanism.

2. FAir HCCA Priority Scheduling (FAHPS) is a controlled access based mechanism and provides better fairness and even higher throughput in the heavily loaded environments. FAHPS relies on alternating CFP and CPs in the MAC layer of 802.11e or 802.11.

3. Multiple Access Hybrid Scheduling (MAHS) is a generic framework for providing guaranteed access to a shared medium in an environment similar to that of 802.11e. A customized version of MAHS is the CAPS algorithm described below. 

4. Controlled Access Phase Scheduling (CAPS) mechanism utilizes the concepts in MAHS and introduces new queuing mdoels and scheduling traffic shaping methods. CAPS enables guaranteeed service provisioning on a per-session basis in the MAC layer of an 802.11e Wireless LAN.

To evaluate the above mechanisms OPNET models for the proposed solution has been developed. Opnet Modeler is used for studying the performance and accuracy of the proposed mechanisms. Opnet offers flexibility, speed, and accuracy in modeling the systems under study.

We have published (or submitted) several papers based on the results gathered through our study and research. Here is a list of these papers:

• Pourmohammadi Fallah Y., H. Alnuweiri, "Performance Analysis of Controlled Access Phase Scheduling Mechanism for Per-Session QoS Guarantee in IEEE 802.11e WLANs",  Accepted for publication in Proc. of Wireless Communications and Networking Conference 2006

• Pourmohammadi Fallah Y., H. Alnuweiri, "A controlled-access scheduling mechanism for QoS provisioning in IEEE 802.11e wireless LANs",  Proc. of first ACM workshop on QoS and Security in Wireless and Mobile Networks, 2005, Montreal, Canada, pp 120-129

• Pourmohammadi Fallah Y, Alnuweiri H.M. "Enhanced Controlled-Access and Contention-Based Algorithms for IEEE 802.11e Wireless LANs", Wireless Networks, Communications and Mobile Computing, 2005 International Conference on Volume 1,  13-16 June 2005 Page(s):409 - 414

• Pourmohammadi-Fallah Y., Elfeitori, A., Alnuweiri. H. , "A Unified Scheduling Approach for Guaranteed Services over IEEE 802.11e Wireless LANs", Broadband Networks, 2004. First Int. Conf. on Oct. 2004 Page(s):375 - 384

Last Updated: Monday, 01 May 2006