A Study On Coding Aware Routing Algorithm For Wireless Mesh Networks

Wireless mesh network is a wireless multi-hop self-organizing network with static backbone nodes.Compared with the traditional wireless multi-hop network structure,it has significant advantages such as large network capacity,wide coverage and high reliability.It is a new network structure with wide application prospects.There are problems such as interference and channel fading in wireless networks,which seriously affect the overall performance of wireless mesh networks.Therefore,how to improve the performance of wireless mesh networks has become a hot topic for scholars at home and abroad.Network coding technology has changed the working mode of nodes in the network,allowing nodes to code and decode received packets,increase the amount of information carried in a single packet,and thus enhance network throughput.Therefore,the network coding technology apply to the wireless mesh network can effectively improve the performance of the wireless mesh network.The improvement of network performance by network coding mainly depends on the number of coding opportunities in the network,network coding aware routing that can actively discover coding opportunities during route discovery has been proposed.This thesis focuses on the wireless mesh routing algorithm based on coding aware.Firstly,the background and significance of the research are fully understood.Then the coding perception principle and the characteristics of wireless mesh network are mastered.On this basis,the routing algorithms in existing wireless mesh networks are analyzed and summarized.This thesis mainly includes the following two aspects of research work:Firstly,existing distributed coding aware routing algorithms in wireless mesh networks have problems such as high network control overhead and low decoding success rate of coded packets.To deal with this problems,a low overhead routing algorithm based on coding aware in wireless mesh networks(LOCA)are proposed.The LOCA algorithm introduces modified network coding conditions and adopts a low-overhead coding opportunity detection mechanism to reduce the amount of information carried in broadcast route request messages,thereby effectively reducing network control overhead.In addition,in order to effectively avoid coding conflicts,acentralized coding opportunity confirmation mechanism is proposed.The simulation results show that the LOCA routing algorithm outperforms the existing distributed coding aware routing algorithms in terms of network control overhead and decoding success rate of coded packets.Secondly,the LCMR routing algorithm has problems such as high load nodes may be selected as forwarding nodes and data traffic of high load nodes can't be adjusted in time,a coding aware congestion avoidance multi-path routing algorithm in wireless mesh networks(CACAMA)are proposed in this thesis.The CACAMA algorithm introduces a congestion prediction mechanism,in the route discovery process,the high load nodes do not need to forward the route request message,which can effectively avoid the high load node being selected as the forwarding node.Then,a multi-path traffic regulation mechanism is proposed to adjust the traffic of high load nodes in the network in time so as to relieve the load of high load nodes and avoid the network congestion.Simulation results show that compared with the LCMR routing algorithm,the CACAMA algorithm improves the network throughput and reduces the average end-to-end delay of the network.Finally,the thesis summarizes the work of the full text,and points out the further research direction of the code aware routing algorithm in wireless mesh networks.