If you're interested in learning how to secure your phone against IMSI-catcher type attacks, here's a blog post covering my team and I's work on Android cellular security features over the last ~3 years https://security.googleblog.com/2023/08/android-14-introduces-first-of-its-kind.html
Android 14 introduces first-of-its-kind cellular connectivity security features

Posted by Roger Piqueras Jover, Yomna Nasser, and Sudhi Herle Android is the first mobile operating system to introduce advanced cellular...

Google Online Security Blog