Software-defined Wireless Mesh Networking And Its Flow Control

Wireless Mesh network is a multi hop network developed from Ad Hoc networks and characterized by decentralization,self-organization,and self-healing.It mostly adopts distributed routing protocols,which makes it difficult to provide differentiated quality of service guarantees for diverse services in the network,nor to choose the optimal routing path based on global network conditions,and it is also difficult to achieve flexible network management.The software defined network separates the data plane and the control plane,and the control logic is centralized in the controller,which can easily achieve network management,traffic scheduling,routing decisions,and other functions.Therefore,this thesis introduces software defined networks into wireless mesh networks,and proposes corresponding solutions to solve problems such as weak Qo S service capabilities and difficulty in finding the optimal path for load balancing in wireless mesh networks.At present,the network is filled with a large number of multimedia services with different requirements for delay,bandwidth,packet loss rate,etc.Traditional wireless mesh networks are difficult to cope with increasingly complex network protocols,network services,and network environments.Therefore,this thesis proposes a multimedia traffic management and scheduling system framework based on SD-WMN(Software Defined Wireless Mesh Network).According to the characteristics of the Mesh network and the software defined network hierarchy,the module designs for the data plane,control plane,and application plane are performed,and the process of obtaining network topology information by the controller in the SD-WMN network is designed,The main functions in the control plane of the framework are to provide quality of service assurance based on business requirements and load balancing routing.In order to achieve network load balancing,this thesis proposes a minimum cost Qo S routing algorithm based on node load and routing overhead.This algorithm combines node load and link overhead to form a transmission cost,and finds a path with the minimum transmission cost under constraints such as delay,bandwidth,and packet loss rate,thereby reducing network congestion,improving network utilization,and achieving load balancing? In order to provide quality of service assurance for business requirements,this thesis improves the redundant bandwidth allocation strategy of the weighted round robin scheduling algorithm,and proposes a hierarchical scheduling mechanism based on strict priority scheduling and improved weighted round robin scheduling algorithm,which maximizes the quality of service for high priority services,while sacrificing the quality of service for sub priority services to provide a minimum Qo S guarantee for low priority services.This thesis uses Networkx and Simpy to build a network simulation environment in a python environment to verify the feasibility of the routing algorithm and traffic scheduling mechanism proposed in this thesis,and compares and analyzes the solution proposed in this thesis with other solutions to illustrate the effectiveness of this solution.The simulation results show that The routing algorithm proposed in this thesis has better performance in transmission cost,packet loss rate,delay,and load balancing? the hierarchical traffic scheduling mechanism proposed in this thesis can meet the Qo S requirements of diverse services.