Research Of SDN Flow Table Request Scheduling And Flow Table Control Mechanism For Smart Grid

The development of communication technology and the high requirements of power have expedited the Smart Grid.The emerging of Software Defined Networking(SDN)provides a new idea for the construction of Smart Grid communication network.As a new type of network technology,SDN decouples the control plane from data plane.Its centralized management and open programmable have many advantages in meeting the diverse demands of Smart Grid.Currently,there are still some problems in the SDN-based Smart Grid quality of service(QoS)safeguard mechanism.For example,there exists a long queuing delay when the controller processes flow table request messages,there exists a long processing delay when the data service matches the flow tables,and there lacks a QoS guarantee strategy for multi-services.This thesis studies SDN flow table request scheduling and flow table control mechanism for Smart Grid.The main works are as follows:1.A service priority-based flow table request scheduling scheme named FTRS is designed.According to the characteristics of different data services in the Smart Grid,the service priorities division is completed through modifying the relevant data structure.Based on priorities,FTRS combines priority queuing scheduling and weighted round robin scheduling,which aims at solving the queuing delay problem of flow table request message in the controller.Meanwhile,the FTRS is analyzed by queuing theory that deduces the mathematical expressions of the average waiting time.In addition,the FTRS is simulated and compared with the first in first out scheduling scheme.The theoretical analyses and simulation results show that FTRS can effectively reduce the queuing delay of the highest priority service,and improve the controller processing performance.2.A QoS-enabled SDN flow table control mechanism named FTCM is designed.Through designing the working mechanism of the controller and switch,vector switching and multipath routing transmission technology are melted into FTCM.Based on SDN virtualization capabilities,the FTCM can achieve the mapping of different priority services to different transmission technology.Simultaneously,the work case of the FTCM is given.In addition,the FTCM is simulated and compared with the existing scheme.The simulation results show that the FTCM can effectively increase the speed of forwarding data packets and improve performance in packet loss rate.Meanwhile,the FTCM meets the delay time and packet loss rate requirements of different priority services.