Samsung Galaxy S4 User Manual page 252

Wi-Fi During Sleep
By default, when your device enter a sleep mode, your Wi-Fi
connection stays on all the time. If the feature is Never
enabled during sleep that current data usage is taken over by
your SIM and its network connection.
1. From the main Settings page, tap Connections tab
Wi-Fi.
2. Press and then tap Advanced
during sleep.
3. Select an available option:
• Always: maintains your current active Wi-Fi connection even
during sleep.
• Only when plugged in: maintains the active Wi-Fi connection
only when the device detects it is connected to a power supply.
This reduced the drain on your device's battery.
• Never (increase data usage): shuts off the current Wi-Fi
connection during sleep and diverts any current data usage to
the cellular network connection.
245
Allow scanning
Allows the Google location service and other apps to scan for
networks, even when Wi-Fi is turned off.
Keep Wi-Fi on
Auto Network selection
Allows the device to automatically switch between Wi-Fi
network or cellular network.
1. From the main Settings page, tap Connections tab
Wi-Fi.
2. Press and then tap Advanced.
3. Tap the Always allow scanning field to activate or
deactivate the feature.
1. From the main Settings page, tap Connections tab
Wi-Fi.
2. Press and then tap Advanced.
3. Tap the Auto network switch to activate the feature that
would allow the device to connect to the best available
signal connection.