How does travel itinerary Code know where you have been? Is it useful to turn off the phone and unplug the SIM card?

Due to the need of epidemic prevention and control, travel itinerary codes are required to be shown in many places at present. The travel itinerary code will record the places you have been in the last 14 days. However, seeing this travel itinerary code, many people are puzzled. They never declare where they went. Why does the travel itinerary code know where they went?

"Communication Big Data Travel Card"

Travel codes began to appear in February 2020. Guided by the Ministry of Industry and Information Technology, China ICT Institute, China Telecom, China Mobile and China Unicom jointly launched the public welfare travel inquiry service. At first, it was a short message query, and later it was upgraded to a scan code query. Later, the travel code was upgraded to a nationwide system.

Using this product is very simple. Use your mobile phone to enter its query page, fill in your mobile phone number and submit it. Then, the travel data of the owner in the last 14 days can be "seconds", which is amazing. The domestic itinerary is accurate to provinces and cities, and foreign countries are accurate to countries.

The purpose of run-length encoding is to master the user's travel trajectory more accurately, which can be used as an important evidence to judge whether the user has reached the middle and high risk area, and can prevent the occurrence of omission and hiding. At first, users can only query by sending short messages, but it didn't take long to upgrade to scanning code query. The key to understanding the user's action trajectory is the mobile phone they carry with them.

Base station positioning, wireless network positioning and GPS positioning.

Each of us has our own ID number, and the ID number is unique. We can find a person accurately through the ID number. Similarly, each communication base station also has its own "ID number" (base station number), and the base station number of each base station is unique. With the base station number, you can quickly find the location of this base station.

The working principle of trip code is to determine the location we have experienced according to the base station signal received by our mobile phone within 14 days, thus listing our approximate trip.

You don't have to memorize travel itinerary codes everywhere. Although you have arrived in a new city, your stay time is less than four hours, so it will not be recorded by travel itinerary's big data. What about the system? It'll make sure you're probably just passing by. There is another phenomenon, that is, er, it is located at the junction of two cities. Although it is out of the province, because the signal base station in this province is relatively strong, the attribution is still determined in the original city.

When the mobile phone turns on the wireless network, it will automatically search the surrounding wireless networks. Once the mobile phone is connected to the wireless network, big data will collect information immediately according to the unique MAC address of the wireless network router in the world. The built-in GPS of the mobile phone will constantly search for satellites in space orbit. Once connected, the satellite system can get the user's specific position according to the signal phase difference, and the error is generally within15m.

Can you "hide" the user's trace by turning off the phone or unplugging the SIM card?

As we all know, even if the mobile phone is turned off, some internal settings are still working, so simply removing the SIM card and turning it off can't hide your trace, because it also involves the IMEI number of the mobile phone identification code. In short, after the mobile phone leaves the factory, it has a unique identification code in the world. Just like ID information, there are two main ways to check the IMEI number of a mobile phone.

First, when buying a new mobile phone, look at the outer packaging of the mobile phone, and generally directly display the identification code of the mobile phone. Second, open the phone settings, click General-About this phone, and scroll down to see the corresponding identification code.

Of course, you can also directly press the *#06# key in the dialing interface, and then the mobile phone identification code will pop up. When the base station detects the mobile phone identification code, it will still produce a series of data, and after analysis, it will produce the user's movement trajectory.