## 2 Background
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Application Level** & **Description** & **References** \\ \hline Prefabricated components & Identify, locate and track prefabricated components through the connectivity of the IoT to realize the visualization and traceability of component information and further improve the prefabricated supply chain system. & [12; 34; 35] \\ \hline Construction system & Plan and optimize the construction process through real-time collection, integration and interaction of construction production process information. & [6; 8; 14; 36] \\ \hline Construction site & Realize the intelligent management, control and optimization of the construction process for the smart construction site. & [37; 38; 39; 40] \\ \hline \end{tabular}
\end{table} 
Table 1: The application of Internet of Things (IoT) in different levels in prefabricated buildings. supported by the IoT to control and optimize the production process of prefabricated components. [PERSON] and [PERSON] [36] designed and implemented a new management system based on the IoT to trace the manufacturing process, optimize the manufacturing schedule and analyze product quality problems for controlling product quality. [PERSON] et al. [8] designed a platform supported by the IoT to optimize the workflow of prefabricated structures' field assembly. In order to further improve the construction efficiency, a BIM platform supported by the IoT was developed by [PERSON] et al. [6] and [PERSON] et al. [14] to realize the visibility and traceability of the construction process and share the information between stakeholders on the platform. As to the construction site level, [PERSON] et al. [37] proposed the concept of a smart construction site and summarized the key elements. For improving construction efficiency and flexibility, [PERSON] et al. [38] combined technologies of the Internet, 3D scanning, BIM, virtual reality, augmented reality and IoT technologies to propose a BIM-based field management model that can more intelligently manage information related to human resources, mechanical and resource allocation, quality control, site supervision, and safety supervision. [PERSON] et al. [39] place extra emphasis on achieving task management and real-time information sharing of the construction site. Similarly, [PERSON] and [PERSON] [40] developed a reliable edge computing infrastructure and applications further to support high-quality, intelligent construction environments. Even though previous research has investigated the application of the IoT in the intelligent construction of prefabricated buildings, most studies are limited at one or two aspects of the IoT. In fact, an ICSPB-IoT is a complex system with various goals. The quality traceability system, assembly service system or supply chain management system investigated by previous studies is just one of the application tasks, while a high-level ICSPB-IoT should achieve an all-around, multisystem or multiplatform interaction and integration. Besides, the service objects, application stages and functions of the IoT in the previous studies are relatively single-mentioned, and most of them are gathered at the component production and on-site assembly stage. A high-level ICSPB-IoT should provide a series of services (e.g., integration design, lean production, transparent transportation, visual assembly, and intelligent building) for the lifecycle of the prefabricated buildings, which covers all participants, including the government, contractors, and owners. Therefore, despite many efforts, there are still knowledge gaps. Specifically, they can be summarized as the following research problems and corresponding solutions in this paper. First: how to develop an information management system that can serve the participants of prefabricated buildings, so as to enhance the ability to make collaborative decisions.