# An IoT-Based COVID-19 Prevention and Control System for Enclosed Spaces
## 1 Introduction  
COVID-19 has resulted in a devastating pandemic, which seems uncontrollable in some countries. By December 2021, the total number of COVID-19 cases had exceeded 286 million, and more than 543 thousand people had died. Regardless of the pathogens that cause infectious diseases, the most effective strategies to prevent them are obvious, such as controlling the source of infection, cutting off the route of transmission, and protecting vulnerable people [1]. The prevention and control of infectious diseases, especially COVID-19, is not only a medical problem but is also influenced by politics, culture, the economy, etc. In practice, appropriate and strict prevention and control measures in epidemiology cannot always be conducted in terms of social management [2]. A case in point is the difficulty in promoting the use of vaccines [3]. Some individuals are reluctant to receive the vaccine because they may deem it futile, noxious, troublesome, etc. SARS-CoV-2 is one of the most infectious viruses, and it has a wide range of transmission routes: respiratory droplets from coughs and snezezes, contact via contaminated objects, aerosols, etc., may cause an infection [4, 5]. Some variants of SARS-CoV-2 have a long incubation period, even with asymptomatic infections. The sensitivity of reagents for detecting infections also needs to be improved. Although the various stringent lockdown policies have contributed significantly to COVID-19 prevention and control, some necessary economic and political activities have been hindered, causing a number of other losses, which have had serious consequences for some countries [6]. Nevertheless, ignoring the pandemic also results in numerous casualties [7]. Hence, the authorities are requiredto prevent and control the pandemic as much as possible without excessively hindering normal life. In this paper, by \"enclosed spaces\", we mainly refer to airless places, such as airport terminals, factory workshops, and shopping malls. Ventilating facilities exist sometimes, but they are not specifically designed for medical use. Compared to open-air areas (plazas, parks, playgrounds, etc. ), the risk of infection is much higher in these locations. COVID-19-positive individuals inevitably pollute the air, contaminate the surfaces of objects, and generate aerosols containing virus particles [8]. All these factors make enclosed spaces dangerous during the pandemic period; moreover, these spaces cannot always be made inaccessible for COVID-19 prevention and control. Many scholars are conducting research on COVID-19 prevention and control at the macro level. Articles exist that evaluate pandemic prevention policies [9; 10]; some researchers focus on the use of big data to address COVID-19 macroscopically [11]; some researchers are interested in the application of machine learning, which is considered to significantly contribute to overall COVID-19 prevention and control [12; 13], etc. In this paper, we mainly focus on the use of Internet of Things for implementing some pandemic control and prevention guidelines in enclosed spaces. Our main concern is how to implement COVID-19 prevention and control measures in specific places. This is an ineluctable compromise between pandemic handling and normal life. In many cases, COVID-19-positive individuals are not aware of their illness; they unintentionally act as a virus \"broadcaster\". Firstly, restricting social gatherings greatly reduces the probability of virus transmission. A COVID-19-positive individual in a large group of people causes in more infections than in a scattered crowd [14]. Thus, a booking algorithm is specifically contrived, guiding individuals to obtain an official permit before entering a region; users are encouraged to apply to enter an area and stay there for a reasonable period of time. In order to obtain a permit as soon as possible, users ought to consciously abide by pandemic prevention guidelines.