Q-HWMP: Improving End-to-End QoS for 802.11s Based Mesh Networks

Wireless mesh network (WMNs) are an emerging technology, presented mainly as a way to build a multi-hop network based on an infrastructure. IEEE has developed a draft 802.11s describing the enhancement of the IEEE 802.11 for mesh networks. This new standard aims to create a new wireless configuration that manages the topology, the quality of radio link and the routing. For routing, two path selection protocols HWMP (Hybrid Wireless Mesh Protocol) and RA-OLSR (Radio-Aware Optimized Link State Routing) are considered. The both routing protocols are inadequate for multimedia applications, such as video conferencing, which is often requiring guaranteed Quality of Service (QoS). QoS routing requires not only finding a best route from a source to a destination according to some criteria (like AirTime metric, hop numbers, etc.) , which is the case of HWMP, but a route that satisfies the end-to-end QoS requirement, often given in terms of bandwidth or delay. This paper tackles this last point by improving the HWMP protocol that handles QoS for real time applications. The goal of the proposed enhancement is to increase the bandwidth utilization and to avoid any network congestions. The method is based on the evaluation of QoS parameters as end-to-end delay or remaining bandwidth and to determine if they can fit with the real time application. Simulation results show that the proposed solution outperform classical HWMP.