iOS 8 supports voice over Wi-Fi, but what about voice over LTE?

One of the nuggets to come out of Apple’s iOS 8 launch was the iPhone’s upcoming support for Wi-Fi calling. It’s a feature that not only will let consumers take advantage of carriers’ voice-over-Wi-Fi service, but is also the first step toward voice over LTE (VoLTE), which will put all mobile communications on IP networks.

The feature showed up as a mere bullet point in a long list of iOS 8’s new capabilities shown on screen at WWDC 2014, but T-Mobile(s tmus) immediately jumped, announcing it would bring its voice-over-Wi-Fi service to the iPhone when the new operating system becomes publicly available this fall. We’ll probably see a similar announcement shortly from Sprint(s s) and other global carriers offering Wi-Fi calling.

While there are plenty of apps that will let you make phone calls over the iPhone’s data connection, it’s been very difficult to make those services work with the iPhone’s main dialer. That’s why T-Mobile has been integrating Wi-Fi calling directly into its Android and Windows phones for years, but on iOS it has been forced to go over-the-top. For a while T-Mobile offered a separate VoIP calling app for iOS called Bobsled.

Image: Shutterstock / Sputanski

Image: Shutterstock / Sputanski

Over the years carrier Wi-Fi calling services have shrunk in importance since most voice plans have moved over to unlimited buckets, though for people living or working in a dodgy coverage zone or international travelers, those calling features are still a godsend. But VoLTE is a just a hop away and it could have a much more substantial impact on consumers and business users.

AT&T(s t) and T-Mobile(s tmus) rolled out their first VoLTE services last month, though right now they’re limited to a handful of Android phones and cities. Both carriers are offering HD voice, but VoLTE promises a lot more than just higher-quality phone calls. Verizon(s vz) has said it will launch VoLTE nationwide this year with integrated video calling, which could compete directly with Apple’s Facetime.

A host of other features like presence, instant messaging and integration with enterprise phone networks are other possibilities. While you get many of those services through third-party apps, VoLTE would integrate them directly into the dialer and attach them to your phone number.

I reached out to Apple about whether VoLTE support would be available on iOS but haven’t heard back yet. In its most basic form, VoLTE isn’t much different than Voice over Wi-Fi. It’s another IP connection, though carriers will be able prioritize voice and video calling traffic over their own 4G networks.