Abstract:

In both wireless local area networks (WLAN) and mobile ad hoc networks (MANET), the IEEE 802.11e medium access control (MAC) protocol is proposed for an effective quality of service (QoS) solution. A number of studies have been done to enhance the performance of 802.11e in MANET by independently adjusting contention window (CW) size of each access category (AC) in every node. However, without the cooperation between the high priority flows and lower priority flows, the QoS goal of high priority flows cannot achieve effectively. In this article, a fuzzy logic based cooperative MAC protocol (FLCMAC) is proposed to cooperate amongst network flows and dynamically adjust access probability of each low priority flow affecting the high priority flows to satisfy their QoS requirement. The simulation results indicate that compared to the enhanced distributed channel access (EDCA) scheme of 802.11e, the FLCMAC consistently excels, in terms of throughput and delay under moderate and heavy background traffic both in single-hop and multi-hop scenarios.

Key words:

802.11e;quality of service;mobile Ad-hoc networks;fuzzy logic;cooperative MAC