Apple's new iOS 8 will support Wi-Fi calling when the version launches in the fall, and T-Mobile US was quick to say on Monday it will support the feature on its customers' iPhones.
T-Mobile was the first U.S. wireless carrier to enable Wi-Fi calling, way back in 2007, on its Android and Windows smartphones, according to a blog posted by T-Mobile's Chief Marketing Officer Mike Sievert.
Like T-Mobile, Sprint also has Wi-Fi calling, which can be used when no cellular signal is available. When the nationwide carriers were asked on Tuesday whether they would support Wi-Fi calling in iOS 8 devices, Verizon Wireless spokeswoman Debra Lewis responded, "I'm not going to speculate on what might be offered in the future on our nationwide network, and we don't offer Wi-Fi calling currently."
Sprint hasn't made any announcements about Wi-Fi calling for the iPhone, spokesman Mark Elliott said. Sprint has five smartphones with the feature included, such as the Samsung Galaxy S4, and plans to expand Wi-Fi calling to more devices in 2014, he said. AT&T didn't respond to a request for comment.
The advantages of Wi-Fi calling would seem to include not having to pay the cellular service cost for a voice call, although T-Mobile counts voice over IP (VoiP) minutes using Wi-Fi calling as minutes against your service plan, according to Jack Gold, an analyst with J. Gold Associates who uses T-Mobile service. "Data is different, but voice is not free with Wi-Fi calling," he said. "You don't really save anything, as the carrier still counts VoIP minutes against your plan."
T-Mobile noted in a fact sheet on Monday that it doesn't charge any additional service charges for Wi-Fi calling. The carrier also noted that customers don't have to integrate another app, such as Skype, and can use their existing phone number. To carriers, the service can reduce the load on their cellular networks.
Gold said he uses the VoIP feature in his T-Mobile phone all the time at home because his cellular coverage is so poor. "The biggest benefit to Wi-Fi calling is for users who have poor carrier coverage," he said.
Given that, is Apple's support for Wi-Fi calling a big deal, at least as big as T-Mobile says it is? Or is it just one of many features coming in iOS 8 that Apple didn't have time to highlight in its two-hour keynote at its WWDC?
Apple flashed a slide of 32 hidden features in iOS 8 that it didn't take time talk about in the keynote. The features include items such as Wi-Fi calling, along with a Braille keyboard, support for Made for iPhone hearing aids and much more.
Some Apple critics quickly said Apple was trying to hide that it hasn't had Wi-Fi calling for years after Android and Windows Phone. Others said Wi-Fi calling isn't as important as Swift, a new programming language and many other announcements Apple made.
What Apple will offer with Wi-Fi calling is not much more than what it already offers with FaceTime video chat on iOS, minus the video, noted Patrick Moorhead, an analyst at Moor Insights & Strategy.
"Wi-Fi calling is really at the noise level for Apple ... that isn't all that important for the iPhone and potential iPhone users," Moorhead said. "With iOS 8, Apple has plugged a lot of competitive holes in messaging and communications, and Wi-Fi calling was one of those features added."
But Carolina Milanesi, chief of research for Kantar WorldPanel, said whether Wi-Fi calling itself is important or not, it fits into Apple's theme of linking iOS with the Mac OS for the desktop. With the benefit of Wi-Fi calling, Apple customers who have both a Mac and an iPhone will soon be able to pick up a voice call at the desktop, if it's within Wi-Fi range. That feature was given plenty of attention by Apple in its keynote, much to the adoration of attendees.
Milanesi said Apple's introduction of Wi-Fi calling is less about convenient calling over Wi-Fi as it is about linking its different devices together. "The phone pretty much got everything from the PC, so to some extent Wi-Fi calling for Apple is bringing the only thing we see as the primary purpose of a phone -- making calls -- to the PC," she said.
Some Apple critics theorized that Apple didn't care about Wi-Fi calling when it first appeared on Windows Phone and Android because Apple customers used the original iPhone on AT&T exclusively. In 2007, AT&T's nationwide coverage was broader than T-Mobile's. Since then, Verizon began selling the iPhone 4 in 2011 and also used the claim of a broad nationwide network. T-Mobile's network has grown steadily since it first got the iPhone in 2013, so, arguably, gaps in coverage and the need for Wi-Fi calling haven't been as necessary.
For whatever reason, T-Mobile customers want Wi-Fi calling, and nearly 5 million of its customers use Wi-Fi calling in any given month. T-Mobile claims it has more customers on Wi-Fi calling than any other carrier, with 17 million Wi-Fi calling-capable devices on its network. By adding its iPhone customers to its Android and Windows Phone customers with Wi-Fi calling means 90% of T-Mobile's smartphones have Wi-Fi calling capabilities.
The Wi-Fi calling feature at T-Mobile is intrinsic to its "Un-carrier" theme with no annual contracts that has been so successful in recent quarters, Sievert intimated. "Our service is one of the most advanced, natively-integrated Wi-Fi calling products in the U.S.," he said. "We have the deep technical knowledge and close partnerships with device manufacturers to deliver the Wi-Fi call quality wireless consumers have come to expect from the Un-carrier."
At least T-Mobile thinks Wi-Fi calling with an iPhone is important, and there's little doubt that T-Mobile's competitive spirit has made both AT&T and Verizon keep a watchful eye on the company.
This article, Wi-Fi calling coming to iPhones in iOS 8, with T-Mobile's support, was originally published at Computerworld.com.
Matt Hamblen covers mobile and wireless, smartphones and other handhelds, and wireless networking for Computerworld. Follow Matt on Twitter at @matthamblen or subscribe to Matt's RSS feed. His email address is mhamblen@computerworld.com.