PEARL is a system containing a server and a large quantity of mobile phones with PEARL clients installed. The system collects CPIs (close proximity interactions) between individuals in their daily life, and then constructs CPI networks from the interactions for further research on respiratory infectious diseases (such as flu and TB).

The rationale behind PEARL lies in two facts: First, the critical infection distance of diseases such as TB is about 10 meters, which is exactly the discovery radius of Bluetooth. Second, a barrier such as a wall can greatly lower the risk of infection, exactly as it decreases the Bluetooth discoverability. Hence Bluetooth is an ideal functionality to approximate the infectious interaction among people: two persons, with Bluetooth functionality turned on at their mobiles, are considered to have an interaction (in the sense of infection of respiratory diseases) if and only if the Bluetooth devices are mutually discoverable.

We launched PEARL program in the following three universities and institutes in 2011.

  • Institute of Computing Technology, Chinese Academy of Sciences (ICT) (for test)
  • South China Agricultural University (SCAU)
  • University of Science and Technology of China (USTB)
  • Here are examples of contact graphs in SCAU from 2011-10-31 to 2011-11-06.