摘要

It is a vitally important problem to form a unified approach to design and implement Internet of Things (IoT). Architecture is the foundation to design and implement IoT systems. In this paper, we divide the recently proposed architectures of IoT into two categories from the function perspective, namely back-end centralized and front distributed architectures, and comparatively analyze them in terms of horizontality, scalability, context-awareness, interactivity, adaptability and others. The analytical results show that USN and IoT-A have more desired properties as reference architectures for future development of IoT. With reference to these architectures, we also summarize the implementation methodologies of IoT in the following three layers, namely interconnection model, communication protocol, and service mechanism, and conclude the recently commonly used methods to build back-end centralized and front distributed IoT systems. Finally, we point out some future work to be done to form a unified approach to design and implement IoT, particularly formally specifying and verifying architectures of IoT and implementing service mechanisms of IoT.