T-Mobile stands alone, for now, in pledge to offer iPhone Wi-Fi calling

T-Mobile US (NYSE:TMUS) is the only U.S. carrier that has so far confirmed it will support Wi-Fi calling for Apple's (NASDAQ: AAPL) iPhone, a new feature Apple is enabling via its iOS 8 software update.

T-Mobile already offers Wi-Fi calling for its customers using Google's (NASDAQ: GOOG) Android and Microsoft's (NASDAQ: MSFT) Windows Phone. Apple expects to roll out the software update this fall. When that happens, according to T-Mobile CMO Mike Sievert, more than 90 percent of all T-Mobile smartphones will feature Wi-Fi calling.

Verizon Wireless (NYSE: VZ) spokeswoman Debi Lewis declined to speculate on whether the carrier will offer Wi-Fi calling for the iPhone. Sprint (NYSE: S) spokeswoman Kelly Schlageter said the company had no announcements to make on the topic. Representatives from AT&T Mobility (NYSE: T) and U.S. Cellular (NYSE:USM) did not immediately respond to a request for comment.

Sprint started offering Wi-Fi calling earlier this year but has limited it so far to Android phones.

Sievert said T-Mobile provides Wi-Fi calling capabilities to more than 17 million devices on its network. He also noted that nearly 5 million T-Mobile customers use Wi-Fi calling during any given month, a number that is continuously growing.

"Since we launched Wi-Fi calling over seven years ago, our engineers have continued to deliver quality and user experience enhancements," Sievert wrote. "As a result, our service is one of the most advanced natively-integrated Wi-Fi calling products in the U.S. We have the deep technical knowledge and the close partnerships with device manufacturers to deliver the Wi-Fi call quality wireless consumers have come to expect from the Un-carrier."

T-Mobile was late to deploy UMTS service and has had to catch up to its larger competitors in terms of network coverage, which may have been a factor in its long affinity for using Wi-Fi to augment its coverage. T-Mobile has offered Wi-Fi calling for free since May 2011 but has offered it since 2007, when it debuted its [email protected] Wi-Fi calling service, which relied on technology from partner Kineto Wireless.

However, T-Mobile has made strides in boosting its network coverage. T-Mobile's HSPA+ network now covers more than 230 million POPs. T-Mobile's LTE network currently covers 210 million POPs, and the company has previously said it plans to increase that to 230 million by mid-year and 250 million by the end of 2014.

For more:
- see this T-Mobile blog post
- see this PC Magazine article

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