Do you receive a welcome message from a province every time you pass by by train?

Yes, the signal received by the mobile phone is used for telephone service through the wireless signal sent by the communication base station installed on the ground by the communication company. There are many such base stations. We take the train, and our mobile phones have to switch many base stations in different places. Each base station is located in a different area. When base stations in different regions receive mobile phones with the same number in different places, they will send preset SMS greetings, and you will get SMS prompts in different regions.