Voice over LTE, aka VoLTE, is a feature that lets you make voice calls over 4G with improved call quality. And soon T-Mobile may require all phones on its network to support it.
T-Mobile will reportedly require all devices connecting to its network to support VoLTE starting in January 2021. That's according to an internal T-Mobile document leaked by Android Police, which goes on to say that T-Mo will stop activating phones that don't support VoLTE on August 4, 2020.
This change will also affect Metro by T-Mobile.
Customers who have activated a non-VoLTE device before the August 4 cutoff will receive a text message soon letting them know about this change.
T-Mo is likely doing all this so that it can repurpose the spectrum currently being used for its 2G and 3G coverage for its 4G LTE and 5G networks. In the leaked memo, T-Mobile explains that this change will "provide T-Mobile customers the best network experience with more capacity and faster speeds."
Most customers on T-Mobile won't be affected by this change. Not only does all of the phones that T-Mobile currently sells support VoLTE, but devices as old as the HTC One M9 and Samsung Galaxy Note 3 are VoLTE-capable. What's more, T-Mo has said that as of Q1 2020, 91% of the voice calls on its network were made using VoLTE.
That is still a sizable chunk of calls not using VoLTE, though. This change will mostly affect customers still using very old devices and some international phones that don't support VoLTE. And for those folks who are going to be affected, it would be good for T-Mobile to announce this change soon because January 2021 is a little over 4 months away, and with the ongoing coronavirus pandemic, some folks may have a hard time quickly getting a new phone.
UPDATE: When asked about today's leak, T-Mobile did not confirm the timing but did say that it "will be phasing out some older technologies over time. The full statement:
"We’re making great progress building a truly transformative nationwide 5G network. As part of that, we will be phasing out some older technologies over time to free up even more capacity for LTE and 5G. In preparation for that and to give customers the best experience, those activating new lines at T-Mobile will need a VoLTE capable device, which is all we've offered for years now and represents the overwhelming majority of devices on the network."