AT&T Adds International Support to Wi-Fi Calling
Wi-Fi calling lets you make clear phone calls in a poor service area, as long as you have a reliable Wi-Fi connection. The service was first introduced in iOS 8 for T-Mobile, became available to Sprint users later in iOS 8’s lifetime, and made its way to AT&T with the release of iOS 9. Just as Verizon finally added Wi-Fi calling support, including free calls to the U.S. when traveling abroad, in iOS 9.3 (see “iOS 9.3 Works the Night Shift, Protects Notes, and More,” 21 March 2016), AT&T has kept pace with its major competitor, expanding its Wi-Fi calling service to the rest of the world.
This means that if you’re an AT&T customer traveling abroad with an iPhone 6 or later running iOS 9.3, you can make calls to or receive calls from the United States over Wi-Fi for free. Calls to numbers outside the United States are still subject to the same rates dictated by your plan.
If you haven’t already done so, here’s how to turn on Wi-Fi calling, which is now supported by numerous carriers in the United States. Go to Settings > Phone > Wi-Fi Calling and enable Wi-Fi Calling on This iPhone. You’ll need to enter your home address for 911 emergency calling purposes (for more details, see “Turn on Wi-Fi Calling in iOS 9,” 28 October 2015). Apple provides more information about Wi-Fi calling as well.
After enabling Wi-Fi calling, the carrier name at the left of the status bar will probably look different when you have a Wi-Fi connection. On an AT&T iPhone 6, it displays AT&T Wi-Fi instead of AT&T LTE. From then on, when you make or receive calls while connected to a Wi-Fi network, they’ll be routed over the Internet instead of the cellular network.
Wi-Fi calling is a life-changing feature if the cellular reception in your home or office is poor, and if you’re an AT&T customer who travels abroad, it could save you a fortune in roaming charges as well.
I could be wrong, but I think that Verizon Wi-Fi calling also supports free calls to US numbers even when you are traveling internationally. This is what it says in the Verizon Wi-Fi Calling FAQ:
"Your Wi-Fi calls to US numbers, regardless of where you are located, are also free of charge (except for 411 and other premium calls). Wi-Fi calls to international numbers will be billed as "International Calling While in the US" (also known as International Long Distance). "
Good catch! I found this in their FAQ and have updated the article accordingly:
"If you travel outside of the US, you may be able to continue calling but dialing 911 through Wi-Fi Calling will not work. Use your cell phone or a local phone to use the appropriate emergency dialing number and contact the appropriate, local emergency service."
"AT&T Adds International Support to Wi-Fi Calling"
Really. Considering the domestic Wi-Fi calling has never worked every time I have tried it (maybe 10 times so far), the fact that AT&T has added international calls to wi-fi calling doesn't seem all that significant to me.
Huh, that's odd. Wi-Fi calling works fine for me all the time. What do you have happen once you turn it on? Perhaps your Wi-Fi network has latency or bandwidth issues, or even some weird upstream filtering?
OK, I just activated it and I have AT&T Wi-Fi followed by the WiFi icon. Now how does the iPhone determine whether to use the cell network or Wi-Fi? Does it use the signal strength of the cell network?
I found out that it only kicks in when the cell signal is "weak" but AT&T did not define "weak".
How might this affect battery life?
If anything, I think Wi-Fi calling will help battery life, by letting the iPhone not try to connect with very weak cellular networks. When the iPhone is on the edge of a cellular signal, it boosts power to the radio to try to make the connection, which uses more battery power.
Unfortunately it's not an option with pre-paid plans (T-Mobile).