how it works
Mobile operators such as T-Mobile and Orange offer the
application to their subscribers to get better indoor coverage
and faster download rates.
This video covers basic setup and configuration of the Application.
It is possible to configure the Wi-Fi Calling Application to enable calls over Wi-Fi only, essentially keeping the phone off the cellular network. If you set the Connection Preference to Wi-Fi ONLY, the application will work over Wi-Fi and, when you go out of range of a Wi-Fi signal, will NOT accept or make calls on the cellular network. This is similar to putting the phone into AIRPLANE mode with Wi-Fi Calling.
The T-Mobile Wi-Fi Calling App has a setting called “Connection Preferences.” To have the App run automatically, this needs to be set to “Wi-Fi Preferred.” Note that you can’t change the connection preferences unless the App is running, so it must be set to ON. Here’s how to check:
On some phones, the App may be set to “Off” from the factory.