IEEE 802.11s MAC Fundamentals

The tremendous success of the Institute of Electronics and Electrical Engineering (IEEE) 802.11 wireless local area network (WLAN) standard led to severe competition. Due to Wi-Fi Alliance (WFA)´s marketing, 802.11 became a universal solution for wireless connectivity. However, still a WLAN depends on wired infrastructure that interconnects the central access points (APs). To become independent of backbone networks leading to cheap deployments, the traditional single-hop approach needs to be replaced by wireless mesh networks (WMNs). Since several years, the research community develops routing protocols designed for wireless multi-hop networks. With 802.11s an integrated WMN approach is under development that adds the necessary functionality for interworking, security and routing. As its medium access control (MAC), 802.11s relies on the existing schemes. However, the current 802.11 MAC has been designed for wireless single-hop networks. Its application to WMNs leads to low performance. The capacity of the wireless medium can hardly be exploited. Thus, 802.11s provides an optional MAC that has been specifically designed for WMN. In this paper we explain the fundamental operation of the 802.11s MAC, explain its extensions and provide detailed simulation results on their performance.