A Low-level Simulation Study of Prioritization in IEEE 802.11e Contention-based Networks

This work deals with the performance evaluation of the IEEE 802.11e EDCA proposal for service prioritization in wireless LANs. A large amount of study has been carried out in the scientific community to evaluate the performance of the EDCA proposal, mainly in terms of throughput and access delay differentiation. However, we argue that further performance insights are needed in order to fully understand the principles behind the EDCA prioritization mechanisms. To this purpose, rather than limit our investigation on throughput and delay performance figures, we take a closer look to their operation also in terms of low-level performance metrics (such as probability of accessing specific channel slots). The paper contribution is threefold: first, we specify a detailed NS2 simulation model by enlightening the typical mis-configuration and errors that may occur when NS2 is used as simulation platform for WLANs and we cross-validate the simulation results with our custom-made C++ simulation tool; second, we describe some performance figures related to the different forms of prioritization provided by the EDCA mechanisms; finally, we verify some assumptions commonly used in the EDCA analytical models