COVID-19 Tracer: Towards Low-cost Passive Close-contacts Searching

COVID-19 is spreading rapidly around the world, which is the enemy faced by all mankind. Since COVID-19 is mainly spread through close personal contact, searching closecontacts is the key to controlling the spread of this virus. This paper designs a new low-cost passive searching system of COVID19 patients' close-contacts using ubiquitous WiFi probe requests, called COVID-19 Tracer. In COVID-19 Tracer, we propose a novel rang-free judgment algorithm for location similarity, which includes two judgment indicators: location similarity coefficient and close contact distance. Finally, we conduct extensive experiments in a school office building. The experimental results show that our system has good performance, and our system's accuracy in judging close-contacts is more than 98%.