You can limit your data usage when abroad by deactivating data roaming. No connection to the Internet via the mobile network when abroad can then be established. You can still use WLAN even though data roaming is deactivated. Remember, you need to activate mobile data.
Find "Mobile Data"
Press Mobile Data.
Activate or deactivate data roaming
Press the indicator next to "Data Roaming" to activate or deactivate the function.
Return to the Home screen
Press the Home key to end the session and return to the Home screen.