Provisioning QoS Support for Multimedia Traffic in IEEE 802.11 WLANs: A Performance Evaluation

The IEEE 802.11 wireless LAN (WLAN) is the most widely used standard nowadays for wireless LAN technology. However, the current standard does not provide QoS support required by the wide range of end applications (e.g., multimedia communications). Thus, a large number of enhancements to the standard are being proposed. This paper summarizes some of the most relevant schemes and presents a survey of the on-going research activities. We also present the upcoming IEEE 802.11e standard being introduced. The IEEE 802.11e standard is a proposal defining the mechanisms for wireless LANs aiming to provide QoS support to time-sensitive applications such as voice and video communications. In this work, first, we analyze the QoS limitations of legacy DCF IEEE 802.11 wireless MAC. Then, different Priority-Based Distributed Mechanisms for QoS provisioning are evaluated. Finally, we carry out a comparative study of these schemes and the IEEE 802.11e (EDCA) upcoming standard, when supporting different services, such as voice, video, best-effort and background traffic.