Why did you receive a short message from Sanmenxia Epidemic Prevention and Control Center?

Because the risk notification may coincide with the trajectory of infected people.

After screening through big data, it does not mean that activities are limited or isolated to inform some people whose activities coincide with those of infected people.

At present, mobile phone positioning mainly depends on the base station of the mobile phone. When traveling, the mobile phone will constantly search for base station signals and choose the base station with the strongest signal to keep connected, so that you can communicate. In the course of your personal activities, although you have never been to a certain place, your mobile phone may be connected to a local base station, and then you may receive a short message from a foreign CDC.