Design And Implementation Of Thing Model For Standard Application

In today’s IoT ecosystem,the emergence of various heterogeneous standards makes it difficult to achieve interoperability between multiple platforms and systems.To solve this problem,several IoT ecological alliances have proposed different solutions.However,the problem of interconnection has not been completely solved.Starting from the semantics and syntax of the IoT,this paper has studied the thing model for standard applications.The main work is as follows:Firstly,the ontology-based ThingSpec model is proposed for the semantic interoperability of the thing model.Combined with industry standard applications,it analyzes the characteristics of multiple standard ontologies and thing models,designs models such as thing,static,dynamic and collection,and builds related classes and instances to realize the integration of multiple standard ontologies.According to the metrics of ontology,the semantic completeness and scalability of this model are verified.Secondly,for the syntactic interoperability problem,the realization process of ThingSpec model is designed.Based on the unified interface principle of RESTful architecture,it completes the mapping from the static design of the model to the dynamic interaction through the CoAP communication method which is suitable for restricted devices.Based on the actual scenario of IoT standard application,it realizes the interaction process between the client and the server,such as behaviors,events,services,and the linkage of multiple devices.Finally,for the problem of network congestion caused by CoAP communication,it optimizes the data filtering mechanism and the interaction processing flow.By adding a data filtering mechanism in the model implementation,it effectively reduces unnecessary network requests in combination with data types.Furthermore,for the time-consuming operations in the interaction,it is optimized by the lazy loading principle,which not only reduces the number of bytes of network data packets in the communication,but also shortens the time length of the corresponding process.