Millimeter-wave 5G does work around corners!

Testing millimeter-wave 5G networks from Verizon and AT&T has been a frustrating experience because they only seem to work when devices are in line-of-sight to cell towers. But Qualcomm challenged me to show that the high-speed system works around corners—and they did.

Using a standard Verizon Samsung Galaxy S10 5G, I stood in front of a Verizon 5G panel at Qualcomm's San Diego headquarters and ran a speed test. Then I walked behind it, and my speed test still worked. I went down a hallway and around a corner, and it still worked. I went into a staircase—still worked. Finally, I went into a conference room, with no windows, and no 5G site visible—and it still worked!

This is a big deal. In Chicago with Verizon and in Dallas with AT&T, I had a really tough time getting a 5G signal when I couldn't actually see the cell site. Obviously, that creates terrible problems for coverage. But Qualcomm's demo showed there's some potential for millimeter wave yet. See the full test in this video:

Distance and materials are a factor here. I was never more than about 400 feet from the site, and there were plenty of glass surfaces for beams to bounce off of and reach me. The conference room wall was sheetrock. A building made of stone or metal could have produced a different outcome.

But I'm now confident that millimeter-wave distance issues will get better with time. I've been seeing about 600-foot cell radiuses in my tests. That's not great. But Qualcomm just introduced a new antenna for home internet devices that can get signal more than half a mile from a site.

There's no way handheld devices will be able to pump enough power to get that kind of range, Qualcomm employees told me. But next year's products may show a middle ground that's better than what we're seeing now.

So why could I get around corners and into stairwells at Qualcomm's headquarters and not in Chicago? When I talked to Recon Analytics founder and analyst Roger Entner, he said the main problem is the NSA.

Seeking 5G Relationship: No NSA, Please

No, not the National Security Agency, or no-strings-attached relationships. NSA is an aspect of early 5G networks and means they are "non standalone." Phones must connect to a 4G LTE network first, which controls the access to the 5G network.

Cell sites are directional; they have "short lobes" and "long lobes." A site is generally aimed in one direction and extends its coverage along a long lobe; when it has coverage in other directions, those lobes are much shorter.

In an NSA situation, the LTE network tells your phone whether 5G is available and whether it should trade up. On mid-band 5G, used by most of the world's carriers and Sprint, this works out pretty well, because the cell sizes and building penetration for 4G and 5G are pretty much the same. The carriers point their 4G and 5G in the same direction. Where you have 4G, you have 5G, and vice versa.

With millimeter-wave, things get weird. It has very different properties from 4G. So a site's 4G long lobe may be aimed at a building, for instance, and its mmWave aspect may be aimed at a right angle down the street—along a short lobe of the 4G site.

As you walk down the street, then, the site's 4G network gets quiet pretty quickly. Turn a corner, and a nearby other 4G site might be stronger, so your phone hands over—even if you could still potentially get 5G coverage from the initial site. That may be what's happening in cities like Chicago.

Now, you may think there's an obvious solution: just tune and angle the 4G sites correctly! But there's a domino effect there. Cell sites essentially interlock, and once you change a 4G site to accommodate its 5G aspect, you have to change all the 4G sites around it, and then you're retuning half of Chicago. You also lose that LTE building penetration you were originally aiming for when you set up that 4G site.

Entner says the real solution is to go to SA, or standalone networks—a form of 5G that doesn't lean on LTE, where your phone actually will be aware of and be able to prefer 5G coverage.

There are other factors in play, too. Entner said that this summer, thanks to new software, phones went from being able to use only "wide" 5G beams to "narrow" beams, which are faster and go farther. That will certainly help with 5G performance.

I'll be retesting Verizon's network soon, and I'll see whether the improved software makes a difference. Standalone networks and phones that support them should be coming out next year. That's when 5G will really turn the corner.

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