From Android 11, the geteduroam app must be used. Older Android versions continue to use eduroamCAT.
If you have upgraded from Android 10 to 11:
The first step is to download the geteduroam app from the PlayStore:
https://play.google.com/store/apps/details?id=app.eduroam.geteduroam
All security settings and the certificate are set up automatically via the app.

When opening for the first time, search for"Bielefeld" in the search field and select Bielefeld University.

The personal login details are now entered here:
User name:
-> BITS-Loginname@uni-bielefeld.de
Password:
-> BITS password (network password)
Then click on Log in .

The app can now be closed and the Wi-Fi connection is established.
The app was only used to set up the Wi-Fi. As a rule, the smartphone will automatically connect to eduroam from then on.