Channel Assignment And Load-balancing In WLAN Mesh Networks

Nowadays,Wireless Local Area Network (WLAN) has been widely applied in more and more fields. However,WLAN is limited by its coverage range. The Wireless Mesh Network (WMN) is a new type of wireless communication network. WMN is capable of self-organization and multi-hop routing. It is a multi-hop broad bandwidth distributing wireless network with high capacity and high transmission rate. It is a multi-hop network formed by peer-to-peer backbone nodes,which provide a way to transmit the data through middle notes,it can obtain wider coverage and larger capacity.How to increase the throughput of WMN is always the final goal. Thus, a lot of researches foucs on channl assignmet and load balance. The main work and contributions are presented in follow aspects:(1) Channl assignmet of Single-Radio Multi-ChannelIn this work, we consider a distributed link-weighted and distance-constrained channel assignment (HBDLCA) algorithm or a multi-channel mesh network, such as community wireless networks, to maximize its throughput. Efficient channel assignment could greatly reduce interference of each link from its neighboring links and subsequently improve the network throughput. We formulate the channel assignment problem as a weighted edge coloring problem, which has the goal of minimizing the maximal link interference of the network between links that are at distance one and conduct a set of experiments to verify the effectiveness of our proposed approach, and show that HBDLCA has better performance and scalability than other proposed schemes.(2) A protocol of Multi-Radio Multi-ChannelIn this work, a hybrid routing protocol TOIRP and a distributed channel assignment algorithm CLBCA of WMN in the multi-channel environment are proposed. The tree base protocol and the traditional AODV routing protocol are integrated together to reduce delay in the routing protocol, which is proposed by HWMP. A new routing metric CETTI is used in this routing protocol, which uses a new method to quantify the interference of communication. It divides interference into two parts:inter-flow interference and intra-flow interference, and it integrates the considerations of hop-count and delay. This improves the throughput of WMN. The channel assignment algorithm is divided into two parts:radio-neighbor binding and channel-radio binding. This algorithm is based on the channel load and avoids the channel-dependency problem which is common in the multi-channel environment. At the same time, it increases the utilization of each channel.(3) Protocol of load-balance base on Channl assignmetIn this work, this thesis proposes a new metric-NLB which is considered the other existing routing metrc and a algorithm-LBRoute_discovery for load balancing. And the metric was through the algorithm that integrated into existing protocols to further improve the routing efficiency. We get simulation results with ETX, Load-count, Hop-count and the SPP. The results show that NLB is well suited for a variety of network environments, and it has good performance.