Research On Routing Protocol Optimization Of Wireless Sensor Networks Based On SDN

The development of wireless sensor networks has promoted the upgrading of information network industry and accelerated the development process of intelligent society.With the increasing demand for networks,wireless sensor networks have a series of problems,such as limited expansion,difficult operation and maintenance and so on.In order to solve these problems,SDN technology is used in wireless sensor networks.SDN realizes the separation of control function and data plane,and implements the software of control strategy,which is conducive to network automation and hardware standardization.At the same time,the programmable characteristics of the data plane make the network tasks flexibly realized by software,which is conducive to the testing and rapid deployment of new services.However,SDN is essentially a high overhead architecture,which is contrary to the energy-saving characteristics of wireless sensor networks.How to balance the energy cost and efficient management of wireless sensor networks using SDN is one of the current research directions.Through the demand analysis of the integration of SDN and wireless sensor networks,this paper proposes an energy-saving and efficient SDN based wireless sensor network architecture SDN-CAM(Software Defined Network-Controller Agent Management).The research contents are as follows:Firstly,a segmented topology discovery method is proposed to solve the problems of long networking time and low efficiency in SDN based wireless sensor networks.In the network initialization stage,because the nodes lack the initial path to the controller,the implementation of distributed topology discovery can speed up the networking speed.After the network initialization,the Controller Agent Management strategy is implemented to select the agent node.The neighbor information of the ordinary node is aggregated by the agent node and uploaded to the controller,which effectively improves the efficiency of data forwarding.Secondly,aiming at the problems of node energy limitation and load imbalance in wireless sensor networks based on SDN,a load balanced routing strategy is designed considering the effects of node energy consumption,node medium and link state.The controller hierarchically processes the whole network structure according to the link quality,and solves the best transmission path by calculating the composite weights of node energy factor,load factor and intermediate factor.Realizing load balancing among nodes is conducive to prolonging the life cycle of the network.Then,aiming at the problem of high network control overhead caused by maintaining centralized control in SDN based wireless sensor networks,a dynamic and low overhead controller agent management strategy is proposed.Taking the minimum control overhead and minimum energy consumption as the optimization objective,the controller dynamically selects agent nodes according to the energy level in each cycle to manage and integrate the control traffic of member nodes.At the same time,the corresponding fitness function is designed to ensure the uniqueness of the proxy node corresponding to the ordinary node.While ensuring the stability of the control level in wireless sensor networks,it can achieve a good aggregation effect of control traffic.Finally,the software defined wireless sensor network simulation platform environment is built and relevant experiments are carried out to verify the good performance of SDN-CAM in network delay,energy balance and control overhead.