You can set your phone to use mobile data automatically when the connection to the Wi-Fi network is weak. To turn automatic use of mobile data on or off, you need to turn on mobile data.
Step 1 of 9
Slide two fingers downwards starting from the top of the screen.
Step 2 of 9
Press the settings icon.
Step 3 of 9
Press Connections.
Step 4 of 9
Press Wi-Fi.
Step 5 of 9
Press the indicator to turn on the function.
Step 6 of 9
Press the menu icon.
Step 7 of 9
Press Advanced.
Step 8 of 9
Press the indicator next to "Switch to mobile data" to turn the function on or off.