Research On Dynamic Generation And Restricted Disseminating Of Control Messages In OLSR Protocol

The mobile ad hoc network has the characteristics of automatic network organization,automatic healing,multi-hop transmission,and support for high-speed movement.The mobile ad hoc network has widely application prospects in the fields of military,wireless sensor networks,agricultural irrigation,emergency communications,drones,and Internet of Vehicles.The technical difficulties of the mobile ad hoc network are mainly concentrated on its routing protocols.Scholars at home and abroad have proposed many routing protocols,and the research on routing protocols is still at an immature stage,and a lot of verification research needs to be done.A routing protocol with strong adaptability and owning high performance is the goal at this stage.Among the mobile ad hoc network routing protocols,the OLSR protocol is one of the widely used and better routing protocols.Based on the classic OLSR protocol,this dissertation makes corresponding improvements to make it more suitable for fast topology changes,high density,and energy limitation.The main work contents of dissertation are summarized as follows:1.Introduces the research background and research significance of mobile ad hoc networks,surveys the development status of mobile ad hoc networks and the research status of routing protocols,especially OLSR protocol.2.Explains the challenges faced by mobile ad hoc network routing protocols,classifies and compares routing protocols that have been proposed at home and abroad,focuses on and analyzes the OLSR routing protocol,explains the data packet format and basic working principle of the OLSR protocol,and Protocol performance indicators.3.On the basis of the original OLSR protocol,in view of the characteristics of active routing protocol control message redundancy and difficult to adapt to the network topology change scenario,an improved type that reduces the number of control messages and improves the overall network performance index is proposed OLSR routing protocol,that is,a limited distribution of dynamic control messages OLSR routing protocol-D-OLSR.The protocol dynamically adjusts the interval of control messages according to the network topologychanges,and limits the distance of topology message flooding.The control messages are improved in time and space,so the routing overhead is reduced and the overall network performance index is improved.4.The NS2 simulation tool was used to simulate a large-scale mobile self-organizing network with fast speed,and the related indicators of the improved routing protocol and several other classic protocols were compared.In the case of different moving speeds of nodes,different network densities,and different network loads,a comprehensive analysis and comparison of the differences in routing overhead,average delay,packet delivery rate,and total energy consumption of several routing protocols.