| Mobile ad hoc network(MANET)is widely used in emergency rescue,military communication and other fields because of its decentralized and non-fixed facilities.However,due to its pure distributed nature,each node needs to frequently exchange routing information and make independent decisions to adapt to the frequently changing topology and network environment,which brings difficulties and challenges to MANET’s network service quality assurance.In order to solve this problem,the combination of Software Defined Network and mobile ad hoc network technology was proposed,namely the Software Define Mobile Ad Hoc Network(SD-MANET).SD-MANET decouples data forwarding function and decision control function,and makes decision from the global perspective,which gets rid of the shackles of local visibility of traditional MANET and inherits the characteristics of MANET’s flexibility,innovatively realizes self-organization,self-adaptation and centralized management of wireless network,and promotes the development of network technology.At present,more and more SD-MANET research has been carried out in military and civilian fields,and the existing network simulation platform generally cannot support the performance simulation of SD-MANET network,so the development of SD-MANET simulation platform is imminent.The SD-MANET simulation platform needs to be able to configure the Quality of Service(QoS)algorithm universally and flexibly,support the cluster simulation of large-scale nodes,and provide solutions to solve the single point problem of the SDN controller to meet the existing needs.The research needs of SD-MANET provide support for China’s military and civilian resear-chers.In order to promote the research of SD-MANET simulation platform and improve simulation efficiency,this thesis conducts detailed research and implementation of QoS and node cluster simulation platform for software-defined ad hoc networks.Based on the basis of SD-MANET data multi-hop transmission,the original Mininet-WiFi platform is improved,and the routing QoS module and queue QoS module are designed,so that routing decisions can be made on services based on data information.Or configure different queue scheduling methods to provide differentiated services.It was finally deployed for validation on the improved MininetWiFi platform.Secondly,in order to give full play to the advantages of combining SDN and MANET and verify the performance of QoS modules in the developed simulation platform,this thesis proposes a routing algorithm based on SD-MANET.The algorithm introduces the concept of intimacy between nodes in social networks,and proposes the effective intimacy index of SD-MANET network,which provides a basis for selecting routing paths with shorter communication distances,more similar flow tables,and better communication links for data transmission.The simulation results show that compared with the ordinary Dijkstra algorithm,the algorithm optimizes the end-to-end delay and packet loss rate of services,and improves the stability of network services.At the same time,the flexibility and applicability of the improved QoS module of the Mininet-WiFi platform are verified.Thirdly,for the SD-MANET cluster research,the optimized porting of the improved Mininet-WiFi platform simulation performance is realized in this thesis,and the number of runnable nodes is increased by about 60%.At the same time,combined with the characteristics of SDN with global topology and MANET topology flexibility,this thesis proposes a controller switching mechanism based on node backup,which is verified in the improved Mininet-WiFi simulation platform.The results show that this mechanism improves the usability of SD-MANET and reduces the delay jitter during controller switching. |
