Figure 2.
Designed hardware in the tracking system: (left/right) tracking device with alarm on/off tracking the length and duration of the mutual contact; (middle) detection gateway collecting data from trackers and communicating with the back-end.
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.