We've had 5G E. We've seen 5G UW. Now it's time for 5G UC. T-Mobile's president of technology Neville Ray tweeted that the carrier's mid-band "ultra capacity" 5G will trigger a "5G UC" icon on the new iPhone 13 series.
That will differentiate T-Mobile's mid-band and high-band network from its low-band 5G network, which performs much more like 4G. In our Fastest Mobile Networks tests, we found that the presence of T-Mobile's mid-band made a huge difference in the carrier's overall performance. T-Mobile also recently put mid-band on its coverage maps.
There's a long, shady history of carriers trying to differentiate their network icons. On Verizon, "5G UW" appears when the carrier is using dedicated 5G airwaves for its service, and not just reusing slices of 4G spectrum. That's pretty legit. But AT&T rebranded its 4G carrier-aggregation network as "5G E," when that system isn't 5G at all. The confusing "5G E" icon has led many people to think they're using 5G when they aren't.
T-Mobile's move is more like Verizon's than like AT&T's. Both T-Mobile's low-band and mid/high-band are legitimately 5G, but only the mid/high band give a noticeably different experience.
The real issue here is that the "5G" brand has become completely devalued because it's been used for the past year to deliver services that are, to the consumer, totally indistinguishable from 4G. (Often, they actually are just 4G, as with 5G E.) The whole tale is a little similar to what happened with 4G, when both AT&T and T-Mobile rebranded some technically-3G services as 4G and later everyone had to differentiate with "4G LTE" to describe the real stuff.
In any case, the new icon is going to be useful. When you see it, you'll know you're likely to have an improved speed and latency experience. And when you don't see it, you'll know the limits of T-Mobile's real 5G coverage.
There's no word yet from Ray about whether this icon will appear on any other phones.