Research On Dynamic Routing Management Based On SDN In Mobile Communication Scenarios

The requirements of communication and computing for mobile tactical tasks are becoming more and more diverse and complex.Mobile tasks such as alliance operations,Need-To-Know(NTK)are proposed to securely share information and protect sensitive information.However,traditional mobile ad hoc networks have not been able to fully satisfy the demands of modern mobile communication tasks.The distributed controller system architecture based on Software Defined Network(SDN)can provide reliable and robust services for mobile and tactical network scenarios,support for the flexible and efficient management of wireless network resources,and meet the needs of the new generation of mobile communication networks.However,the dynamic characteristics of the network increase the difficulties of system management,which lead to a decrease in overall performance of the network.To address above issues,a dynamic routing management scheme under the distributed controller architecture is studied in this thesis.A dynamic controller placement method and a reliable route management scheme are proposed for the control plane and the data forwarding plane respectively to optimize the network response delay and improve the service quality.The main work is as follows:1.Firstly,for the dynamic controller placement ploblem,the coverage constraint of controllers and the costs of switches migration are taken into account to establishe a mathematical model in which the network response delay is selected as the optimization target.Then an approximate algorithm based on linear programming rounding is proposed to solve the problem,and the quality of the algorithm solution is theoretically analyzed.2.Aiming at the problem of the high service transmission loss rate caused by the links failure because of high mobility of nodes,a reliable route management scheme is proposed.The scheme handovers the routing path of the serviced data flows based on prediction of the link reliability in advance,improves the service transmission reliability by combining a reactive link failure recovery scheme,and adds a re-routing mechanism to improve the utilization of the network bandwidth resource.Meanwhile,the scheme is implemented in the distributed controller system which has been established.3.In order to simulate the mobile communication network scenarios in the experiment,the node mobility module and controller interaction interface are extended in the simulation platform Mininet-WiFi.Both the node location information which outputed by Mininet-WiFi and Matlab are used to verify the effectiveness of the dynamic controller placement method,and an experiment is designed in distribute controller system to verify the effectiveness of the reliable route management scheme.The results of experiment show that the controller placement method of this thesis can effectively reduce the network response delay,the effect is 3%~8% higher than that of dynamic controller placement algorithm in existing researches.And the reliable route management scheme effectively improves the transmission reliability and throughput of the network,10% ~14% throughput can be improved compared to the link failure recovery scheme.The studies of this thesis can improve the overall network performance of distributed controller system in mobile communication scenarios,which is of great significance to the construction and development of the new generation in mobile communication network systems.