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Please use this identifier to cite or link to this item: http://bura.brunel.ac.uk/handle/2438/2558

Title: Enhancing IEEE 802.11MAC in congested environments
Authors: Aad, I
Ni, Q
Barakat, C
Turletti, T
Keywords: Wireless communications
IEEE 802.11
MAC
CSMA/CA
Simulations
Markov chains
Publication Date: 2005
Publisher: Elsevier
Citation: Elsevier Computer Communications Journal. 28 (14) 1605-1617
Abstract: IEEE 802.11 is currently the most deployed wireless local area networking standard. It uses carrier sense multiple access with collision avoidance (CSMA/CA) to resolve contention between nodes. Contention windows (CW) change dynamically to adapt to the contention level: Upon each collision, a node doubles its CW to reduce further collision risks. Upon a successful transmission, the CW is reset, assuming that the contention level has dropped. However, the contention level is more likely to change slowly, and resetting the CW causes new collisions and retransmissions before the CW reaches the optimal value again. This wastes bandwidth and increases delays. In this paper we analyze simple slow CW decrease functions and compare their performances to the legacy standard. We use simulations and mathematical modeling to show their considerable improvements at all contention levels and transient phases, especially in highly congested environments.
URI: http://bura.brunel.ac.uk/handle/2438/2558
Appears in Collections:Electronic and Computer Engineering
Dept of Electronic and Computer Engineering Research Papers

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