Which of the following indicates that there may be a tail base station nearby?

Which of the following conditions indicates that there may be a tail base station 1 nearby? Pay attention to the strength of the mobile phone signal: if the signal suddenly interferes or even disappears during the call, there may be a pseudo base station around you.

2. Pay attention to the content of receiving short messages: you often receive advertising short messages or various "preferential" messages with similar contents, and also remind you that you may receive information from pseudo base stations.

3. Don't click on unfamiliar links at will: pseudo base stations can change their numbers, so they will pretend to be financial institutions, communication companies, etc. Send all kinds of scam messages to the public. When you receive such short messages with similar numbers, remember not to click at will without verification.