1 Find "Wi-Fi preferences"
Slide your finger downwards starting from the top of the screen.
Press the settings icon.
Press Network & Internet.
Press Wi-Fi preferences.
2 Turn automatic use of mobile data on or off
Press the indicator next to "Allow use of mobile data when Wi-Fi is connected" to turn the function on or off.
3 Return to the home screen
Press the Home key to return to the home screen.