What does it mean to have an R in the upper left corner of Motorola's cell phone signal? How to solve it?

Roaming is to remind you that you have roamed to another communication company's network. Is your mobile phone a foreign product? If so, there is no need to worry about using domestic cards in China. If you can make a phone call, send a text message and surf the internet, don't worry about it. Otherwise, you can check the mobile network and data traffic in the settings, and check the box that does not use data network when roaming.