The wireless carrier is expanding its existing Wi-Fi calling and texting service with promises of more coverage in the home and in the air.
You'll need a recent iPhone with the latest version of Apple's mobile operating system, but you won't incur any charges beyond the usual international calling rates.
The smartphone feature is useful when customers find themselves in an area with weak or no carrier coverage.
AT&T customers with the new iPhone 6S and 6S Plus, as well as last year's iPhone 6 and 6 Plus, can now make calls over Wi-Fi.
AT&T customers, rejoice; Wi-Fi calling is available on your iPhone with iOS 9. Here's how to enable it.
If successful, the limited time project will become generally available in September.
Four of Apple's iPhones will be able to take calls over Sprint's Wi-Fi networks, a boon if your signal -- or minutes -- are running low.
Curious about Wi-Fi calling and what it entails? CNET has the rundown on what you need to know.
The company, which already offers free mobile phone service via Wi-Fi networks, is trying to make a name for itself with the introduction of a $99 Android handset.
The low-cost waterproof smartphone joins a growing roster of devices capable of making phone calls over Wi-Fi.