With the rapid growth in popularity of wireless data services and the increasing demand for wireless connectivity, Wireless Local Area Networks (WLANs) have become more widespread and are making their way into commercial and public areas being almost everywhere including business, office and home deployments. WLANs based on the IEEE 802.11 standards enjoy an exceptionally high popularity owing to their simplicity of setup, configuration, and management, increased deployment flexibility, operability in unlicensed frequency bands, low cost, and connectivity with minimal infrastructure changes. Lately, the need for real-time multimedia services over WLANs to support applications such as Voice over IP (VoIP), audio/video (AV) streaming, Internet videoconferencing, IPTV, distance learning systems, entertainment and gaming programs has dramatically increased. The impressive proliferation of networking scenarios (e.g. multihop and mesh networks) and applications (e.g. real-time multimedia services) not natively supported by the original standard has boosted the design of several protocol extensions, which have been proposed and evaluated by the research community, the industry and the standardization groups. However, despite recent advances in wireless technology, many research issues such as bandwidth management, power conservation, compatibility with legacy networks and error resilient design still need to be addressed. Furthermore, the dynamically-varying and error-prone nature of the wireless medium pose further challenges in providing efficient channel access mechanisms and Quality of Service (QoS) support over WLANs. This special issue presents a collection of selected papers that represent advances towards the performance enhancement of IEEE 802.11 WLANs. A total of 37 high-quality papers were received from the open call and finally eight were selected to be published in this issue. The first paper, “A Control Theoretic Approach for Throughput Optimization in IEEE 802.11e EDCA WLANs”, by Patras, Banchs and Serrano, proposes a control theoretic approach to adapt the congestion window (CW) to the conditions of the WLAN, based on an analytical model of its operation that is fully compliant with the IEEE 802.11e standard. The controller is a Proportional Integrator, able to Mobile Netw Appl (2009) 14:693–696 DOI 10.1007/s11036-009-0160-y