Despite improvements to their LTE coverage, the iPhone 6 and iPhone 6 Plus are missing support for a new LTE band that T-Mobile is deploying. That means that some T-Mobile customers in the United States who buy the new phone won't benefit from improvements that their carrier is making to the network.
Earlier this year T-Mobile acquired 700 MHz radio spectrum from Verizon. In announcing the acquisition, T-Mobile promised that this would help the company build out its coverage area in two places T-Mobile has historically been weak: inside of buildings and in rural areas with limited tower coverage.
T-Mobile has made several smaller regional 700 MHz acquisitions since then, all associated with "A-block" spectrum it needs to build out its network. The company's already deploying the 700 MHz network, but there's a hitch: Very few phones support it. T-Mobile said it's expecting handsets to support the LTE band associated with that spectrum to roll out in the fourth quarter. A few Android phones already do. But it looks like the iPhone 6 and iPhone 6 Plus won't.
To access 700 MHz A-block spectrum, a cell phone needs to support LTE Band 12. Both the iPhone 6 and iPhone 6 Plus support more LTE bands than any iPhone before them, but LTE Band 12 isn't on the list.
The new isn't all bad for T-Mobile customers and the iPhone 6 and 6 Plus. The devices sport faster LTE than before and Voice over LTE (VoLTE) support. Wi-Fi Calling is also supported.
Long a feature touted by T-Mobile, Wi-Fi Calling switches the phone to use Wi-Fi for voice calls when it's available. It's been a staple of Android phones sold by the network, but it's now coming to iOS (iPhone 5, 5S and 5C models on T-Mobile will also support it, if they're upgraded to iOS 8).
Are you on T-Mobile or are you thinking of switching? Were you hoping that the new iPhones would support the new 700 MHz improvements T-Mobile is making? Let me know.