Design And Simulated Implementation Of QoS Routing Algorithm In Multi-Radio Multi-Channel Wireless Mesh Networks

Wireless Mesh Network (WMN) is a novel type of wireless network structure which is a promising solution for the last mile access due to the characteristics of high data rate, high throughput, easy expending, low primary cost, and stable performance, etc. Since there are various kinds of applications transmiting in WMN while the wireless channel is time-varying, it is a challenging task to perform a good Quality of Service (QoS) for real-time appliactions. Therefore, it is meaningful to ensure the QoS in WMN from the routing perspective and provide a QoS routing mechanism based on node available bandwidth information.This thesis firstly presents the current researches and key technologies of WMN and analyzes the shortages of the classical Optimized Link State Routing (OLSR) protocol. Then, the thesis improves the OLSR protocol by applying the estimation of available bandwidth, and illustrates the cross-layer design is an effective and feasible method to solve the QoS issues. To implement the algorithm, the thesis expands the format of HELLO message and TC message and propoes a new routing protocol called Cross-Layer QoS OLSR protocol which can utilize the logical routing information based on the physical routing to ensure the QoS of real-time application. Furthermore, the thesis explores multi-radio and multi-channel WMN to take full advantage of multiple interfaces in each node to guarantee the QoS requirements of real-time applications, while can increase the throughput of WMN.Finally, this thesis makes the performance simulation based on QualNet5.0.2platform for CLQ-OLSR protocol. Results show that CLQ-OLSR can provide the QoS guarantee based on link available bandwidth for real-time applications, and it not only can reduce the end-to-end delay and delay jitter and improve the packet delivery rate but also is able to increase the throughputs of WMN without obvious cost.