Sent from my Sprint Samsung Galaxy s3 running Liquid Smooth v2.7 with a 7000mah extended battery... Because I'm not a chick, a guy with dainty hands or an HTC one user
If the baseband is read as unknown, you may need to flash a radio for your device, as something may have happened to cause your phone to not have a radio installed. (Did you recently restore a Nandroid backup?)