Research And Design On QoS Routing Protocol For Mobile Wireless MESH Network

Wireless mobile mesh network (WMN) is a new wireless network, which is completely different from the traditional wireless networks. Because the WMN does not require the support of central node and each wireless device can be both the user node and transit node, which connects to the backbone by multi-hop manner through the wireless MESH network router, it has high reliability, collision mitigation, deploy easily, high scalability, easy maintenance and so on. Now there are a lot of researches for wireless mobile mesh networks at home and abroad, mainly including routing protocols, MAC layer, multicast protocols, power control, security, QoS. Routing protocols of MESH network are one of the research hotspot.In this thesis, an improved protocol for QoS routing service issue of MESH network based on QoS-AODV routing protocol is proposed. Firstly, an improved algorithm is proposed based on the neighbors' stability in the network layer from the aspect of stable routing. The improved algorithm counts the neighbors' stability by the average number of hello packets received from neighbors each connection per second. Besides, a LSQ-AODV protocol and a QSQ-AODV protocol are proposed separately for finding the most stable path locally and the most stable path globally.Compared with AQ-AODV protocol, the results of simulation show that LSQ-AODV and GSQ-AODV protocols increase the network throughput, delivery ratio and reduce the end-to-end delay. Specially, GSQ-AODV protocol is more suitable for mesh network.Secondly, an improved routing protocol GSQ-AODV-LR is proposed based on local repair of backup route from the aspect of route recovery. In the improved protocol, the node sends repair packets to the pre-nodes, making it switch to their backup routes to continue transmitting data, so it can reduce the overhead by avoiding flooding routing control packets. Compared with the AQ-AODV and GSQ-AODV protocols, the results of simulation show that the improved protocol can reduce the overhead with guaranteeing throughput, end to end delay and delivery rate.