Design And Implementation Of Network Topology Discovery Algorithm For Wireless Sensor Networks Based On SDN

This thesis introduces the basic concepts of wireless sensor network and SDN, and analyzes the current research and application status of wireless sensor networks and aiming at the limitation of traditional wireless sensor networks, a new type of wireless sensor network architecture based on SDN is proposed in this thesis by using the method of numerical control separation and centralized control in order to solve the problems of energy consumption of nodes in traditional wireless sensor networks, network instability, short network lifetime and other issues, and to improve the transmission performance of the network.At the same time, a physical topology discovery algorithm is designed for the new sensor network in this thesis. The core idea of the algorithm is that the whole network is composed of a controller and several common nodes, the controller initiates a topology request to the whole network and it is processed according to the information received, ordinary nodes periodically broadcast Hello messages to maintain their neighbor list, reply and forward the messages from the controller, and also feedback the change of neighbor list to the controller. These two parts cooperate to complete network topology discovery and topology maintenance.In this thesis, we build a real hardware platform for wireless sensor networks with raspberry pie 2 development board on the basis of the simulation of the topology algorithm and successfully accomplish the network topology discovery and topology maintenance function, and then successfully accomplish the topology discovery in the tree type indoor scene of star topology and network topology in the corridor scene.The real hardware platform test results show that the new topology discovery algorithm can effectively and accurately accomplish the initial network topology discovery and maintenance even if the entire network topology is not clear in the sensor network scenarios.Based on SDN, this thesis proposes a new wireless sensor network architecture model and a physical topology discovery algorithm and then effectively reduces the resource cost, improves the resource utilization and improves the network stability.