Research On QoS Routing Protocols For Wireless Ad Hoc Networks

Wireless Ad Hoc Network is a self-organizing network without central entity and any infrastructure, which consists of multiple mobile devices with wireless transmitters and receivers. The mobile terminal could perform routing forwarding. Any network topology can be built via wireless links. In recent years, with the rapid development of wireless communications and increasing popularity of multimedia applications, QoS service in Wireless Ad Hoc Networks has become a hotspot in the area of wireless communications. However, mobile multi-hop, the lack of resources of wireless bandwidth, the limit of battery energy of nodes and dynamic changes of network topology in Wireless Ad Hoc Networks cause new difficulties and challenges for QoS research.First of all, in order to solve the problems of routing instability and recurrent flooding for wireless Ad Hoc network caused by topology dynamic changes and short network lifecycle resulted from energy-limited of nodes, this thesis proposes a routing algorithm, which could improve the reliability of routing protocols and reduce flooding routing to improve network performance and extend the network lifetime.Secondly, this thesis proposes a new routing protocol called CLMQSR based on the MSR routing protocol. CL_MQSR is a multi-path QoS routing protocol based on cross-layer design concept. The protocol utilizes the resources of Wireless Ad Hoc network in different layers considering the available bandwidth and restricted energy of the node at the same time. The protocol utilizes minimum available bandwidth of the node, the residual energy of the path and the length in the buffer queue of link-layer node as routing measurement, and improves multi-path selection strategy. Simulation results show that the protocol improves the reliability of routing and extends the network lifecycle.Finally, aiming at high costs of exiting QoS routing establishment, this thesis proposes a location-based QoS multi-path routing protocol (LQSRP). This protocol could fix the location information of the nodes via GPS (Global Positioning System) and create a forward neighbor table for each intermediate node.The thesis uses the open source network simulation software NS2. The simulation results show that the protocol could reduce the routing load and improve packet delivery rate of routing and performance of the whole network compared with QoS_MSR.