Research On Routing Algorithms Oriented To Load Balancing In Wireless Mesh Network

With the development in recent years,WMN(Wireless Mesh Network),which has the advantages of self-healing,high capacity and high reliability,has become the development direction in the field of wireless communication networks.Hybrid mesh network combines the advantages of backbone mesh network and client mesh network.It is the most common network structure of wireless mesh network.It has the advantages of simple and flexible networking,can integrate a variety of wireless networks and wide network coverage.In the future,the roof of the house at home,the medical system of the hospital,the public monitoring system and the temporary construction system of disaster can be built and deployed using wireless mesh network.The key problem affecting the further development of wireless mesh network is load balancing.Partial overload uses some resources,which leads to excessive load on some nodes in the network,resulting in unbalanced utilization of resources in the wireless mesh network as a whole.For the research of load balancing in wireless mesh networks,researchers have made some research achievements in routing metric,multi-path,multi-channel and multi gateway deployment,but some aspects are not perfect.For example,there is less consideration on the layering of hybrid mesh networks,and the design of path measurement in the network is not comprehensive enough.This paper studies hybrid mesh networks from the aspects of comprehensive metric routing algorithm and multi-path QoS(Quality of Service)guarantee,and puts forward practical and reliable solutions.The main research work includes the following two aspects:(1)In view of the insufficient consideration of node load and the inapplicability of plane routing algorithm in hybrid networks,this paper proposes a comprehensive metric hybrid routing algorithm for load balancing in hybrid wireless mesh networks.Firstly,the algorithm improves the expected transmission time measurement according to the remaining bandwidth of the network link,and then puts forward the independently designed node load measurement according to the regional load concentration and node congestion degree of the node.Finally,the comprehensive routing measurement is constructed and weighted based on the parameters such as node load,link quality and hops.Secondly,according to the hierarchical structure characteristics of the upper and lower layers of the hybrid network,it is proposed to use table driven routing mechanism in the backbone layer and reactive routing mechanism in the client layer.In the process of routing,the comprehensive routing metric is used as the judgment basis,and the nodes with stable backbone layer and low load are preferentially selected as the optimal path of data transmission,so as to realize the efficient end-to-end data forwarding.NS3 software simulation shows that compared with CHRP(Cooperative hybrid routing protocol)and other algorithms,the algorithm has higher end-to-end throughput in the hybrid WMN environment,avoids high load nodes during data transmission,solves the problem of uneven load in the network and improves the overall network performance.(2)Aiming at the problems of unstable single route transmission,high overhead of secondary route discovery and QoS guarantee of multi service transmission in hybrid WMN,this paper proposes a multi-path QoS guarantee routing algorithm with high dynamic wireless mesh network load balancing.Firstly,aiming at the deficiency of instability treatment of all client nodes,this paper designs a further distinction between the stability of mobile nodes in the network according to the changes of nodes’neighbors.Then,aiming at the problems of multi constraints such as node stability,delay,bandwidth and load,the multi criteria decision algorithm TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)algorithm is introduced.The algorithm calculates the distance from each alternative to the good and bad ideal solution by integrating the multi-input conditions with different weights,so as to select the best scheme from multiple alternatives under multi-objective conditions.Finally,by modifying the routing request packet and reply packet structure of AOMDV(Ad hoc On-Demand Multipath Distance Vector Routing)algorithm to record various parameters of different paths.we can find the reliable and stable routing path of active and standby switching in the process of routing.Simulation results show that the performance of the algorithm is better than AOMDV algorithm.With the increase of the moving speed of the hybrid network,the path selected by the algorithm is more stable,and the end-to-end throughput and packet loss rate are reduced at least,which ensures the stability of data transmission.The algorithm effectively solves the problem of uneven load in the network,ensures the reliable transmission of data services with multiple QoS requirements to a certain extent,and improves the network transmission efficiency.Finally,the thesis summarizes the work of the full text,and puts forward the prospect of the next research work.