Research On Terminal Switching Mechanism Of WLAN Based On SDN

With the widespread application of WLAN,the dense deployment of wireless access points,and the rapid growth of the number of mobile terminals,it has become a common practice for mobile terminals to switch their access points in the network as the user's location changes.However,due to the inherent drawbacks such as closed architecture and lack of centralized control,the traditional switching mechanism cannot effectively control the switching delay and balance the network load.Therefore,it cannot provide high-efficiency and high-quality network services,and cannot meet the increasing high demand of users for wireless networks.In view of the shortcomings of the traditional terminal switching mechanism,this paper introduces an innovative network architecture such as Software-Defined Networking(SDN),and proposes an WLAN architecture based on SDN with its control forwarding separation,centralized control,and open programmable features.To make up for the drawbacks of the traditional WLAN architecture.Based on the architecture,a seamless handover mechanism and a load balancing switching mechanism are proposed.The control network switches the delay and balances the network load to improve the overall performance of the network when the terminal is switched.The main work and contributions have the following aspects:Firstly,considering the shortcomings of traditional WLAN,thispaper proposes a WLAN architecture based on SDN that can achieve seamless handover and load balancing handover.The architecture has the characteristics of control forwarding separation,centralized control,and open programming,which makes the network flexible and controllable,the controller has a global perspective,and the user can write the application according to his own needs.Secondly,this paper proposes a seamless handover scheme for the traditional handover mechanism that cannot effectively control the handover delay.The scheme firstly controls the handover delay by streamlining the access procedure of the terminal handover,and then reduces the data propagation delay by releasing the flow table in advance,so that seamless handover can be realized.The simulation experiment is carried out through the Mininet-WiFi experimental platform.The results show that compared with the traditional WLAN,the scheme reduces the overall delay of the terminal handover and improves the network service quality.Thirdly,in view of the insufficiency of the traditional switching mechanism to effectively balance the network load,this paper proposes a load balancing switching scheme.Firstly,the controller's global perspective and centralized control capabilities are used to collect,control,and analyze information.Then,the load balancing module uses the algorithm proposed by the controller to calculate the weight and formulate the switching strategy according to the information provided by the controller.Finally,the controller is based on the load.The switchingpolicy developed by the equalization module sends a flow table to implement terminal switching.The simulation experiment is carried out through the Mininet-WiFi experimental platform.The results show that compared with the traditional WLAN,the scheme improves the system throughput and improves the network resource utilization.