I have never been to Xi 'an. Why does the travel itinerary code show that I have been there?

I haven't been to Xi 'an for two reasons, one is signal cross coverage, and the other is system error.

1, signal cross coverage

Nowadays, in order to enhance the signal and improve the communication quality, many operators will carry out signal cross coverage in two adjacent cities, which means that everyone's mobile phone may be connected to the local signal tower or the signal tower in the adjacent city. If you visit the signal tower of the corresponding city, you may be located in a neighboring city.

2. System error

This kind of mistake is more common, especially for mobile users in China. However, the operator did not give an accurate explanation as to why it went wrong. If you have never left the local area, but have been in a different place, you can call the operator's official customer service phone to verify. If the operator verifies that he has never been to a certain place, but the trip code appears, he can ask them to delete it.

Principles of travel code

The working principle of trip code is to judge which city base station you contacted by analyzing the signaling data and bill data of mobile phone.

In the process of using the mobile phone, whether talking, texting or surfing the Internet, you need to connect to the base station. The specific information of each base station, including the location and number, is clear to the operator. Once everyone goes somewhere to surf the Internet or make a phone call, they will contact the base station, and then the base station will record everyone's information.