Wi-Fi Calling lets you make and receive calls over Wi-Fi when there’s a poor mobile phone signal, or none at all.
There’s no additional charge for using the Wi-Fi Calling service. All calls you make with it will use your plan’s minutes as usual. Simply connect to a Wi-Fi network and set up Wi-Fi Calling on a compatible phone.
Currently, your phone won’t automatically transfer from a Wi-Fi signal to a mobile signal, so your call may be cut off if you lose your Wi-Fi signal.
It’s also not possible to send and receive texts over Wi-Fi, however this will be available soon.