Design And Implementation Of An Iot Device Simulation System Based On EdgexFoundry

IoT system based on the edge computing architecture can significantly enhance the service response capability and improve the practicality of the IoT by providing near-end services.The utilization of edge computing technology will promote the IoT to take root in more and more vertical industries.Terminal devices,with a wide variety and a large number,are the basic component of the IoT system.In the process of large-scale IoT system development and network performance analysis,terminal equipment simulating systems are introduced to simulate the protocols and tasks of various IoT devices,also to construct complex application scenarios based on multi-device combinations.Hence,such simulating system is very important to the testing and evaluation of the IoT systems with edge computing architecture.This thesis first investigated several IoT device simulation systems and analyzed their design ideas and functional characteristics,then summarized their shortcomings in simulating the task offloading process and building complex business scenarios.Some IoT device authentication schemes were also investigated,and their working process and shortcomings were summarized.Based on the investigations above,the requirements analysis,architecture design and database table design of the IoT device simulation system for the cloud-edge-terminal collaborative platform were carried out.The system was divided into four modules:device management module,application management module,task scheduling module and device access control module.Each module was designed and implemented in detail.An IoT device authentication scheme based on a two-level blockchain model was also proposed.The global-level blockchain is constructed between edge servers of the IoT system to record and share the public keys of devices,identity of the edge network in which the devices are located,and the current availability of each device in a decentralized manner,cooperates in the authentication process that need to share information globally in the IoT system,such as device registration and activation and authentication after the device crosses the edge network.Another blockchain is constructed between edge servers and gateways in a certain edge network to record and share the public keys of devices,identity credentials,which cooperates in the authentication process when the devices move within the edge network.Finally,the system was deployed to the cloud-edge-terminal collaborative IoT simulation platform.Integration tests were carried out to verify the functional correctness of the system,the rationality of the identity authentication scheme,and the performance indicators of the system.The results showed that the system proposed in this thesis has more complete functions and good running stability.