| In recent years, WMN(Wireless Mesh Network) is a new direction in the field of wireless communication, and it aims to provide users with high speed Internet access service, with the increasing number of Internet users, the multi-gateway WMN appeared,meanwhile, highly efficient and stable routing protocol becomes indispensable technologies to improve the WMN network performance, and they are important and hot topics for experts and scholars.In this dissertation, the research is based on multi-gateway WMN, in order to realize fast switching and gateway load balancing, the layer two routing protocol LTWMP(Layer Two Wireless Mesh Protocol) has been analysed, combined with its characteristics and defects, this thesis put forward the improved algorithm. The main contents can be included as follows:(1) A fast switching routing protocol based on LTWMP, which called FS-LTWMP(Fast-Switching Layer Two Wireless Mesh Protocol). This protocol gives a new calculate method of transmission quality, updates the transmission quality of every node in real time, put the instantaneous transmission quality as the basis of routing, and put forward the path switching conditions to avoid frequent switching and ping-pong effect. Build environment to test the performance of FS-LTWMP protocol, and test the delay when disconnect one node, the experimental results show that FS-LTWMP protocol can recover normal communication in a relatively short time when network environment changes.(2) A gateway load balancing protocol based on LTWMP, which called LB-LTWMP(Load Balancing Layer Two Wireless Mesh Protocol). This protocol considers both path quality and gateway load as the metric of gateways selection, which can achieve the optimal gateway selection and path selection. According to the characteristics of LTWMP protocol is closely related to the Linux kernel, this paper put forward a method to obtain the gateway load using the Linux kernel function, to make nodes learn the load of all gateways, load information is added to the Hello packets, when choosing the gateway, the node considers both path quality and gateway load to equilibrium data traffic, which can solve the problem of load imbalance and avoid congestion in gateway nodes. Then build environment to test the performance of LB-LTWMP protocol, test the throughout and the delay in different load cases to reflect the merits of the network performance, the experimental results show that the network performance is greatly improved. |
