I have never been to Huludao. How to display travel itinerary code?

If you have never been to Huludao, of course, your itinerary code will not show Huludao. Just like the picture below, it will only show the places you have been in the last 14 days. Of course, there won't be if you haven't been there, unless you are very unlucky and happen to encounter a data analysis error.

How does travel itinerary Code know where everyone has been?

The working principle of the travel code is actually very simple, that is, by analyzing the signaling data and bill data of the mobile phone, we can judge which city base station we contacted.

In the process of using mobile phones, everyone needs to connect to the base station, whether talking, texting or surfing the Internet. The operator knows the specific information of each base station, including its location and number. Once people go somewhere to surf the Internet or make a phone call, they will contact the base station. At this time, the base station will record everyone's information, so operators can clearly know where everyone has been and these data will be uploaded to the travel code system. Scan the code and you will see the latest 60.