Load Balancing Techniques for Wireless Mesh Networks: A Survey Banani Das Department of Information Technology Assam University Silchar, India e-mail: banani.das.bd@gmail.com Sudipta Roy Department of Information Technology Assam University Silchar, India e-mail: sudipta.it@gmail.com Abstract—Wireless Mesh Networks (WMNs) are evolving to be the key technology for next generation wireless networking because of its advantage over other wireless technologies. However, many challenging technical issues still exist in this field to be addressed. Network load balancing is one of the important challenges in WMNs. As because the traffic volume in a WMN is expected to be very high, load balancing becomes a crucial part of it. Network load balancing enhances the scalability and availability of network. Load balancing can be used to extend the lifetime of a Mesh Network. In a WMN, where multiple paths to the destination node are very common, load balancing is the best approach to increase network throughput and to reduce congestion. In order to provide a better understanding of the load balancing challenges of WMNs, this paper presents a detailed investigation of the various load balancing techniques for WMNs that has been proposed so far. Keywords - Wireless Mesh Networks; Load Balancing; Gateway; Routing Metric. I. INTRODUCTION A. Wireless Mesh Network (WMN) WMN has emerged as a key technology for next generation wireless networking because of its advantages over other wireless technologies. WMN has been widely accepted as a replacement for areas of MANET. WMN [1] is a communication network made up of radio nodes organized in a Mesh topology and is a packet- switched network with a static wireless backbone. The topology of wireless backbone is fixed and modifications to infrastructure can only result from addition or removal or failure of access points. WMNs are the combination of two point-to-point or point-to-multipoint networks. Mesh Networks are semi- mobile. The nodes may change but the overall coverage is somewhat constant. Mesh nodes normally are connected to every other node within range creating a mesh of coverage paths. MANETs slowly develop into Mesh Networks as the number of nodes increases, the Mesh Networks are usually designed to cover large geographic regions than MANETs. WMN consists of wireless access and wireless backbone network, in contrast to any other wireless networks. It is dynamically self-organized, self-configured, self-healing, easily maintainable, highly scalable and reliable service with the nodes in the network, because if a single node goes down, other nodes are available. It is also anticipated to resolve the limitations and to significantly improve the performance of other wireless networks. WMN architecture is composed of three different network elements: 1) Network Gateway (NG): This network element allows access to the wired infrastructure and other local networks. More than one gateway can be deployed in a WMN. Gateway is normally a computer that operates in all five layers of network model. 2) Access Points (APs): APs are low cost, flexible, and easy to deploy form of network backbone spanning over wide areas. They can be used to enhance capabilities. The APs are assumed to be static, with a low failure probability, and no power constraints. 3) Mobile Nodes (MNs): It include a wide range of devices such as laptops or cell phones with varying degrees of mobility. B. Overview of Load Balancing in WMNs A typical WMN can have three level hierarchical structure. At the top, there are the IGW or the gateway nodes that are directly connected to the wired network. The second level of hierarchy consists of nodes called Access Points (APs)/ Mesh Routers (MRs) that forward each other’s traffic in multi-hop fashion towards the IGW. These MRs form the backbone of a WMN and are relatively static. At the lowest level of hierarchy are the Mobile Clients / Nodes (MNs) or the end users connected to the MRs for accessing the wired network services. The 2013 International Symposium on Computational and Business Intelligence 978-0-7695-5066-4/13 $26.00 © 2013 IEEE DOI 10.1109/ISCBI.2013.57 247