IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163 __________________________________________________________________________________________ Volume: 02 Issue: 05 | May-2013, Available @ http://www.ijret.org 871 A STUDY ON QOS AWARE ROUTING IN WIRELESS MESH NETWORK Arnab Kundu 1 , Suvajit Bhattacherjee 2 , Gairik Saha 3 1 Asst. Professor, Department of E.C.E., B.I.E.T., Suri, Dist.-Birbhum, PIN-731101, W.B., INDIA 2, 3 Student, Department of E.C.E., B.I.E.T., Suri, Dist.-Birbhum, PIN-73101, W.B., INDIA a.kunduwb@gmail.com, suvajit.ece.biet@gmail.com, gairik.biet@gmail.com Abstract Wireless Mesh Networks (WMN) mainly consists of mesh clients and mesh routers. It is mainly effective as an economically successful and a promising technology for providing wireless broadband services. Mesh routers basically form the backbone of the network (WMN) and hence has the minimum mobility. They interconnect the mesh clients and the wireline backbone network. In order to approach the wireline level or same or near QoS, the Wireless Mesh Networks must be QoS aware. In this paper we have worked on the effect of variable transmission power to achieve the desired SNR and to maximize the number of active links at the same time for each links in the network and analyze different approaches to maintain the QoS routing of a wireless mesh network. Index Terms:AODV; AQOR; DSDV; MANET; OPNET; QOS; WMN -----------------------------------------------------------------------***----------------------------------------------------------------------- 1.INTRODUCTION Wireless local area network is a process which provides Internet connectivity to mobile users, connection to the infrastructure. All the mobile users must reside within the basic service set (access point) with a radius up to 250~300meters. In relatively large areas we need to deploy a large number of access points (AP) to provide full coverage. In order to provide video-on-demand, online gaming and emergency communication services, end to end quality of services (QoS) must be up to that mark which is dependent on bandwidth. The QoS routing mechanism in a multi-hop wireless network faces some challenges due to the impact of interference. The available bandwidth in each an every node is dependent upon the interference occurred by its neighboring nodes within the interference range. Wireless mesh networks (WMNs) are easy to maintain, robust and provide reliable service coverage. 2. WIRELESS MESH NETWORK WMNs consist of two types of nodes: mesh routers and mesh clients. Other than the routing capability for gateway/repeater functions as in a conventional wireless router, a wireless mesh router contains additional routing functions to support mesh networking. To further improve the flexibility of mesh networking, a mesh router is usually equipped with multiple wireless interfaces built on either the same or different wireless access technologies. Compared with a conventional wireless router, a wireless mesh router can achieve the same coverage with much lower transmission power through multi- hop communications.[1]. In this architecture, mesh clients represent other networks such as cellular, IEEE 802.11, IEEE 802.15, and sensor networks. The gateways, mesh routers and the mesh clients form three-tier architecture [1], [2], [3]. Fig1: Wireless Network Architecture Unlike other distributed clustering schemes, ACE employs an emergent algorithm. Emergent algorithms much like artificial neural networks evolve to optimal solution through a mix of local optimization steps. The main idea of ACE is to allow a node to assess its potential as a CH before becoming one and stepping down if it is not the best CH at the moment. The algorithm works in iterations that do not have to be synchronized at the individual nodes. Spawning new clusters and migration of existing ones are the two functional components of ACE. A node spawns of new cluster when it decides to become a CH. It broadcasts an invitation message to recruit its neighbors. Upon getting the invitation, a neighboring sensor joins the new cluster and becomes a follower of the new CH. At any moment, a node can be a