When roaming, you can decide to connect/disconnect to a data service:
- Select Settings.
- Select More > Mobile networks.
- Slide the on/off switch to activate or deactivate data roaming.
- When data roaming is deactivated, you can still use a WiFi connection.
- When you're abroad, a fixed panel will appear in your phone's notification drawer to allow you to easily enable or disable data roaming at any time.