2015 International Conférence on Communication, Information & Computing Technology (ICCICT), Jan. 16-17, Mumbai, India 978-1-4799-5522-0/15/$31.00©2015 IEEE Congestion Aware Load Balancing for Multiradio Wireless Mesh Network Kruti.N.Kapadia Electronics and Telecommunication Sardar Patel Institute of Technology Mumbai, India Kruti.kapadia2001@gmail.com Dayanand.D.Ambawade Electronics and Telecommunication Sardar Patel Institute of Technology Mumbai, India dd_ambawade@spit.ac.in Abstract— A new kind of wireless multi-hop network architecture called Wireless Mesh Network (WMN) has recently attracted much attention. In this paper, we propose congestion aware multipath routing protocol called EAOMDV-LB for multi- radio multiple interface wireless mesh networks (WMN). The protocol calculates multiple paths using proposed airtime congestion aware (ACA) metric and performs load balancing by computing queue utilization of multiple interfaces of a node. Moreover, the effective load balancing technique maintains data transmission on optimal path by diverting traffic all the way through congested area. WMNs have recently gained a lot of popularity due to their rapid deployment, instant communication capabilities and support for many types of application. For these applications, network congestion is the main reason for lower throughput and longer delay. Most of the present routing protocols for WMN’s are not designed to adapt congestion and optimal link quality. The simulation results using ns2 reveal that our proposed load balancing scheme performs better than AOMDV in terms of throughput, end-to end delay with high traffic density. Keywords—Wireless Mesh Network; multiple interfaces and multiple channels; airtime link cost metric; round trip time; congestion; load balancing I. INTRODUCTION As various wireless networks evolve into the next generation to provide better services, a key technology, wireless mesh network (WMN), has emerged recently. In WMNs, nodes are comprised of mesh routers and mesh clients. A WMN is dynamically self-organized and self- configured, with the nodes in the network automatically establishing and maintaining mesh connectivity among themselves. WMN is a promising wireless technology for numerous applications e.g., broadband home networking, community and neighborhood networks, enterprise networking, building automation, etc. [1]. This feature brings many advantages to WMNs such as low up-front cost, easy network maintenance, robustness, bandwidth fairness, easy deployment and reliable service coverage [2]. WMNs will greatly help the users to be always-on-line anywhere anytime. Moreover, the gateway/bridge functionalities in mesh routers enable the integration of WMNs with various existing wireless networks such as cellular, wireless sensor, wireless-fidelity Worldwide interoperability for Microwave Access (WiMAX), Fig. 1. Infrastructure Wireless Mesh Network [1] WiMedia networks [3]. Based on the functionality of the nodes, WMNs can be classified into three categories: Infrastructure backbone, client backbone and hybrid. Mesh routers are used to form a multi-hop and multi-path wireless backbone capable of communicating with gateways and clients. Mesh clients can form self organized ad hoc networks which can access services by relaying requests to wireless backbone network. The hybrid mesh network architecture is a combination of infrastructure and client meshing and is expected to be the best choice in the next generation WMNs. Some of the technical challenges in WMNs are load balancing, optimal routing, fairness, network auto configuration and mobility management [4]. Various routing metrics such as ETX, ETT, WCETT and MIC have been proposed but they cannot guarantee the quality and efficiency of the path. Typical shortest path routing using hop-count or any of the above metrics can lead to load imbalance and inefficient use of network capacity [5]. In WMNs, most of the traffic is routed through the mesh routers for accessing the Internet, so the traffic is mostly from mesh clients towards the Gateways or from Gateways to the clients. If multiple mesh routers choose the best path to route their traffic towards the Gateways, then the load over that path will extensively increase and in return will decrease the overall network performance [6]. If routing decisions do not take into account the nature of traffic patterns and user demands,