HD Voice on the T-Mobile iPhone 5: A Winning Advantage?

T-Mobile USA featured HD voice as a big part of its Apple iPhone 5 rollout this week. It appears that HD voice is finally starting to register with the U.S. media as a desirable feature, but will it be enough to bring more customers over to the “Un-carrier”? Or just a temporary boost?

First, the facts: T-Mobile USA is the first U.S. carrier to support HD voice on the Apple iPhone 5 via its GSM HSPA+ network. Period. Numerous other carriers around the world have supported HD voice on the iPhone 5 since its introduction last fall, all on HSPA networks, with some carriers introducing HD voice with the iPhone 5 launch in the fall of 2012 – a testament to Apple’s influence, since most were clearly capable of supporting HD voice long before then.

T-Mobile’s support of HD voice should be considered a big dig toward at least one carrier. Sprint, having locked into a big deal to buy millions of iPhones on a multi-year contract, couldn’t get HD voice support on its iPhone either on its CDMA 1X Advanced network or for Voice over LTE. 

Given Sprint’s early 2012 hype of HD voice support on 1X Advanced, there’s probably at least one untold story revolving around Sprint’s network upgrades and/or Apple’s relationship with Sprint. The carrier reportedly signed a 2011 deal to buy $20 billion in Apple iPhones over a four-year period.

I realize we’re talking about Apple, but $20 billion in sales should get you some consideration to support a key feature upon product rollout. 

Will T-Mobile continue to have an “exclusive” lock on offering HD voice in the United States? Will it have an exclusive on the iPhone 5?

We’ll probably know more at the CTIA show in May (Start scheduling your media appointments now). AT&T will have HD voice as a part of its Voice over LTE (VoLTE) rollout expected in the second half of this year, but has given no indications it will provide HD voice on its existing GSM/HSPA network. From a technical standpoint, rolling out HD voice on its existing HSPA-based network is a software upgrade within the network – one T-Mobile quietly accomplished without incident in December 2012 before formally launching service in January.

AT&T’s party line is that HD voice takes up too much spectrum for voice calls – a fascinating claim, given the number of European carriers who have managed to find enough room to offer it. Perhaps the real reason is voice calls don’t generate much incremental revenue these days, while streaming services and other data-cap-maxing apps do.

LTE networks bring a different set of issues. The Apple iPhone 5 doesn’t currently support VoLTE, and Apple has (as usual) given no indications when VoLTE will arrive, either as a software upgrade under iOS or as a new feature on an iPhone 5 S or iPhone 6.  At this point, I’d say the odds are 60/40 in favor of an iOS software upgrade for VoLTE. This would also give Sprint and Verizon HD voice on their respective devices when their networks fully support VoLTE sometime next year, assuming Apple doesn’t see VoLTE as a way to move new iPhones.