I've been testing the Samsung Galaxy S20 Ultra on all of the US 5G networks, and low-band 5G phones from AT&T and T-Mobile are displaying "5G" icons when the phones aren't actually using 5G networks to transfer data.

The Samsung Galaxy S20 series will be the real introduction to 5G for many Americans, but the state of 5G is weird. There are three "layers" of the 5G "cake."

Low-band 5G uses long-distance 4G airwaves and is the one you're most likely to see on AT&T and T-Mobile, but it often isn't faster than 4G.

5G uses long-distance 4G airwaves and is the one you're most likely to see on AT&T and T-Mobile, but it often isn't faster than 4G. Mid-band , used by Sprint and most of the rest of the world, is a good balance between speed and coverage.

, used by Sprint and most of the rest of the world, is a good balance between speed and coverage. High-band, or millimeter-wave (mmWave), is extremely short-distance but can be 10x the speed of 4G.

On AT&T and T-Mobile, the small Galaxy S20 will only have low-band and mid-band 5G. The Galaxy S20+ and Galaxy S20 Ultra have all three kinds. But AT&T and T-Mobile appear to be feeding their low-band phones a "5G" icon if the cell they're attached to is capable of 5G, even if the network and phone use only 4G technologies for the time.

You can be on a low-band 5G cell and have the network decide you should use 4G for several reasons. Right now, low-band 5G can't combine with low-band LTE or high-band Licensed Assisted Access (LAA) LTE, so if a network decides that one of those will give you better performance, you'll be on 4G but see "5G."

This 5G icon does not necessarily mean you are transferring data over 5G.

There are other, more arcane considerations as well. For instance, you could have a cell site that has low-band 5G and mid-band LTE, but the low-band 5G panel is pointing in the wrong direction for you (yes, they're directional) so you attach only to the mid-band LTE even though the cell shows you the "5G" icon.

This is all in addition to AT&T's misleading "5GE" icon, which is just a label for its best 4G LTE carrier-aggregation system.

If you see a "5G+" icon on an AT&T phone, like on the image at the top of this story, it's on high-band 5G, and the experience will definitely be different. That network has relatively little coverage, though. T-Mobile does not badge its low-band, high-band, and soon-to-be-mid-band 5G differently, but its high-band is currently only available in seven cities.

Looks Like 5G, Feels Like 4G

Low-band 5G in the US right now is so almost-pointless that it's not really worth a new icon. 5G is not magic; many of its advantages come because it can use more spectrum in bigger channels than 4G does. 4G maxes out at 20MHz channels and 140MHz of total usage at once. 5G rolls in with 100MHz channels and up to 800MHz of total usage.

AT&T and T-Mobile are both right now reserving so little spectrum for low-band 5G that it might as well be 4G. They aren't taking advantage of those big channels. In many places, their low-band 5G channels are only 5MHz, and the networks will decide that a collection of available 10-20MHz 4G channels will offer a better overall experience. So you will see "5G" and use LTE.

Crowdsourced data from Ookla Speedtest Intelligence shows that low-band 5G isn't making much of an experiential difference. On T-Mobile, 5G downloads using the OnePlus 7T Pro 5G McLaren averaged 61Mbps in December, while 4G speeds on the same model averaged 44Mbps. On AT&T, low-band 5G downloads on the Galaxy Note 10+ 5G averaged 78Mbps in December, while 4G speeds on the same model averaged 70Mbps.

AT&T's Gordon Mansfield explained to me a while ago that this is part of a long game. Starting this summer, the carriers get access to DSS, a technology that lets them dynamically turn over more 4G spectrum to 5G. Next year, they get new chipsets that can better combine channels of low- and mid-band spectrum. Standalone network mode will improve the 5G experience by making latency plummet.

So there's a technical reason, not just a marketing reason, for the carriers to be starting in this currently humble place with 5G. That "5G" icon massively overpromises, though.

Sprint and Verizon Are a Different Story

Sprint's and Verizon's indicators are more honest, for different reasons.

In Sprint's case, its 4G and 5G networks use the same frequency band and overlap each other tightly enough that there aren't situations where you'd be on a 5G cell, but the network wouldn't want to use 5G. So if you see "5G," you're probably using 5G. That said, in recent tests I haven't been seeing a speed advantage for Sprint's 5G over 4G in New York, and the Sprint/T-Mobile merger makes everything cloudier. I'll have a story on that soon.

Verizon's '5G UWB' icon means fast 5G, but it can be hard to find.

Verizon only shows its 5G icon when the phone is actively transmitting data on a 5G network. This is more honest, but also makes it hard to figure out where 5G coverage is, because if you pass through a 5G area while your phone isn't transmitting any data in the background, your phone still says 4G. It's under-promising, rather than over-promising, but it's still a problem.

So ... it's a mess. But at least if you get a Galaxy S20 series phone, you'll be relatively future-proof as the carriers improve things over the next year.

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