Distributed fair scheduling in a wireless LAN
MobiCom '00 Proceedings of the 6th annual international conference on Mobile computing and networking
Dynamic tuning of the IEEE 802.11 protocol to achieve a theoretical throughput limit
IEEE/ACM Transactions on Networking (TON)
Quality of service schemes for IEEE 802.11 wireless LANs: an evaluation
Mobile Networks and Applications
Runtime Optimization of IEEE 802.11 Wireless LANs Performance
IEEE Transactions on Parallel and Distributed Systems
An Analysis for Differentiated Services in IEEE 802.11 and IEEE 802.11e Wireless LANs
ICDCS '04 Proceedings of the 24th International Conference on Distributed Computing Systems (ICDCS'04)
Performance analysis of the IEEE 802.11 distributed coordination function
IEEE Journal on Selected Areas in Communications
IEEE 802.11 protocol: design and performance evaluation of an adaptive backoff mechanism
IEEE Journal on Selected Areas in Communications
Supporting service differentiation in wireless packet networks using distributed control
IEEE Journal on Selected Areas in Communications
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In this paper, we derive, based on the analytical model developed by Cali et al., a multi-class model to study how to adaptively tune parameters in IEEE 802.11e EDCA and support service differentiation in WLANs. Through analytical modeling, we demonstrate that by assigning appropriate different attempt probabilities (or contention window sizes) to stations of different classes, it is feasible to provide (proportional) service differentiation and achieve pre-specified targeted throughput ratios among different classes, while at the same time, maximizing the total system capacity. We also extend the derived theoretical model to analyze the role of AIFS and TXOP values on service differentiation perceived by different traffic classes. We show that, to achieve QoS guarantees (i.e. throughput differentiation) and high channel utilization, it may not be desirable to allow tuning of multiple parameters (e.g., both the contention window sizes and the AIFS values). Instead, the design dimension should be kept small by turning only one set of parameters, while keeping the other two sets of parameters for all the access categories fixed (i.e., setting the AIFS values of all access categories to 2, which is equivalent to AIFS=DIFS). We also elaborate on how to on-line measure parameters needed for calculating the best value of the contention window size. Both the analytical models and the proposed approaches for practically incorporating theoretical findings into IEEE 802.11e EDCA are validated through detailed ns-2 simulations and empirical experimentation on a Linux-based MADWifi driver for wireless LAN devices with the Atheros chipset.