T-Mobile, band 12 LTE, and E911: new details arrive on unlocked phone controversy
Yesterday we shared with you an interesting, if not just a little bit confusing story about what was going on between manufacturers of unlocked smartphones and T-Mobile, where phones that should be fully capable of using the carrier’s band 12 LTE were finding manufacturers disabling that support – phones sold unlocked and seemingly independent of T-Mobile. It appeared that an issue with VoLTE support and E911 routing was being put forward as the explanation for such actions, at least by Motorola as it killed-off band 12 access for the GSM edition of the new Moto E, but the full picture wasn’t yet clear. T-Mobile has still yet to issue a formal comment on the matter, but Android Police was able to connect with some off-the-record T-Mobile sources that attempt to lay everything out.
Here’s the issue: if a phone that lacks VoLTE support is connected to T-Mobile’s network, and can only access band 12 at the moment, no calls can go through, including attempts to reach emergency services via E911. In theory, a phone should be able to use roaming and connect to E911 through another network, but since band 12 support looks strong, the phone doesn’t know to do this. And with no VoLTE, the call simply can’t go through.
Why not just implement VoLTE support, then? As carriers are wont to do, T-Mobile requires a lengthy (and no doubt costly) certification process before approving models (including unlocked handsets) for VoLTE access.
When manufacturers aren’t willing to take that step, T-Mobile is instead asking them to disable band 12 LTE – and the phone-makers appear to be listening. Even when that involves unlocked phones, they appear willing to do what’s necessary to appease the carrier, lest they ruin the relationship needed for sales of other explicitly T-Mobile-supported models.
The mystery is what will happen if someone says “no.” T-Mobile doesn’t appear to have a formal way by which to enforce its requests, and it’s entirely possible some OEM will decide T-Mobile’s band 12 VoLTE E911 issues are a T-Mobile problem, and not one that an independent phone-maker should have to worry about.
In the end, this whole situation becomes a complicated mix of legal requirements, technical oversights, and back-room deals between big companies. While in a perfect world, a carrier might just offer service to any compatible phone, in the real world the nature of “compatibility” is far from a black or white question, and there are clearly gray areas like this one that raise tricky questions about just where responsibilities lie.
We doubt this is the last we’ve heard of T-Mobile and its band 12 predicament, but for now it looks like most manufacturers will continue heeding the carrier’s wishes.
Source: Android Police