What Is 5G?

After three years of promises, 5G is finally spreading fast in 2022.

The new mobile network tech was supposed to ignite a “fourth industrial revolution(Opens in a new window),” according to Verizon—and it has not done so. The “5G” that most Americans have experienced up until now has felt just like 4G, with a new icon. This year, though, AT&T and Verizon are turning on new networks—the much talked about C-band—which along with T-Mobile’s more mature mid-band network, might finally change things.

All of the hullaballoo over 5G, with no real new experiences, has led people to wonder what the big deal is. Is what we’re seeing right now even 5G at all? The answer is yes—technically. It turns out that 5G technology and a “5G experience” are very different things, and right now in the US we’re getting the former without the latter.

Things will start to turn, though. T-Mobile’s “ultra capacity” 5G won our Fastest Mobile Networks 2021 tests by showing speeds much faster than 4G, and now that they’re launching, the new C-band networks are starting to change the game for AT&T and Verizon.

There’s even a new player: Dish just launched a 5G network in Las Vegas, and pledges to reach more than 125 cities and towns by June.

5G is an investment for the next decade, and in previous mobile transitions, we’ve seen most of the big changes happening years after the first announcement. Take 4G, for instance. The first 4G phones in the US appeared in 2010, but the 4G applications that changed our world didn’t appear until later. Snapchat came in 2012, and Uber became widespread in 2013. Video calls over LTE networks also became big in the US around 2013.

Because the 5G transition is so complicated, and because we’ve been having a pandemic for two years, this time the shift may take even longer. Scientists in Finland who helped developed 5G technology say that it may be 2027 before we see the robotics, smart objects, and augmented reality we’re been promised.

For now, the first big 5G application is a 30-year-old idea: home internet service. T-Mobile and Verizon are using their 5G networks to better compete with cable home internet, adding some competition into a very uncompetitive realm.

What Is 5G?

What Is 5G?

1G, 2G, 3G, 4G, 5G

First of all, if you’re hearing about 5G Wi-Fi or AT&T’s “5G E” phones, they aren’t 5G cellular. Here’s a full explainer on 5G vs. 5G E vs. 5GHz: What’s the Difference?

And if you’re hearing that 5G means millimeter-wave towers on every lamppost, that’s not true. That’s only one of the three main forms of 5G we’re seeing right now.

The G in this 5G means it’s a generation of wireless technology. While most generations have technically been defined by their data transmission speeds, each has also been marked by a break in encoding methods, or “air interfaces,” that makes it incompatible with the previous generation.

1G was analog cellular. 2G technologies, such as CDMA, GSM, and TDMA, were the first generation of digital cellular technologies. 3G technologies, such as EVDO, HSPA, and UMTS, brought speeds from 200kbps to a few megabits per second. 4G technologies, such as WiMAX and LTE, were the next incompatible leap forward, and they are now scaling up to hundreds of megabits and even gigabit-level speeds.

5G brings three new aspects to the table: bigger channels (to speed up data), lower latency (to be more responsive), and the ability to connect a lot more devices at once (for sensors and smart devices).

It isn’t a clean break with 4G. 5G phones all need 4G networks and coverage. At first, all 5G networks used 4G to establish their initial connections, something called “non-standalone.” We’re starting to move away from that now into “standalone” networks, but they lose significant performance without an assist from 4G. Part of the 5G spec allows 5G phones to combine 5G and 4G channels invisibly and seamlessly to the user. So most connections will be combined 4G/5G links for quite some time.

That symbiosis between 4G and 5G has caused AT&T to get overenthusiastic about its 4G network. The carrier has started to call its 4G network “5G Evolution,” because it sees improving 4G as a major step to 5G. It’s right, of course. But the phrasing is designed to confuse less-informed consumers into thinking 5G Evolution is 5G, when it isn’t.

While 2G and 3G are going away soon(Opens in a new window), 4G has at least a decade ahead of it as part of the 5G equation. If you find yourself needing to buy new phones or equipment because 3G is being turned off, you can have confidence in 4G.

How 5G Works

Like other cellular networks, 5G networks use a system of cell sites that divide their territory into sectors and send encoded data through radio waves. Each cell site must be connected to a network backbone, whether through a wired or wireless backhaul connection. 5G changes the way data is encoded, and offers many more options to carriers in terms of airwaves to use.

5G networks use a type of encoding called OFDM, which is similar to the encoding that 4G LTE uses. The air interface is designed for much lower latency and greater flexibility than LTE, though.

The new system opens up “high-band,” short-range airwaves that didn’t work with 4G technology. But 5G can run on any frequency, leading to three very different kinds of 5G experiences—low, middle, and high.

5G isn’t much faster than 4G on the same old radio channels. Instead, the 5G spec lets phones use much wider channels across a broader range of frequencies. The carriers and the FCC have to make those wider channels available, though, and that’s where they’ve largely fallen short.

With 4G, you can combine up to seven, 20MHz channels to use a total of 140MHz of spectrum. Most of the time, though, phones are using 60MHz or less.

With new phones in low- and mid-band 5G, you can combine three 100MHz channels for 300MHz usage—and stack several more 20MHz 4G channels on top of that. In high-band 5G, you can use up to eight 100MHz channels. But if you don’t have the airwaves available, you don’t get the speeds.

Carriers can also flexibly share channels between 4G and 5G using dynamic spectrum sharing (DSS). DSS makes the walls between 4G and 5G channels movable, so carriers can split channels between 4G and 5G based on demand. That’s what Verizon has been using for its “nationwide” 5G. It doesn’t free up any new airwaves for 5G—it just reuses odds and ends of 4G—so we haven’t seen DSS 5G offer much better performance than 4G.

Low-band 5G operates in frequencies below 2GHz. These are the oldest cellular and TV frequencies. They go great distances, but there aren’t very wide channels available, and many of those channels are being used for 4G. So low-band 5G is slow. It acts and feels like 4G, for now. Low-band 5G channels are from 5MHz in width (for AT&T) up to 20MHz (for T-Mobile), so you can see they aren’t roomier than 4G. If your phone’s network indicator just says “5G,” you are on low-band.

Complicating things, AT&T and T-Mobile low-band phones sometimes show 5G icons when they aren’t even using 5G, making it hard to tell any difference.

Mid-band 5G is in the 2 to 10GHz range. That covers most current cellular and Wi-Fi frequencies, as well as frequencies slightly above those. These networks have decent range from their towers, often about half a mile, so in most other countries, these are the workhorse networks carrying most 5G traffic. Most other countries have offered around 100MHz to each of their carriers for mid-band 5G.

There are several different slices of mid-band being used in the US. Some of them are controversial; the airline industry has been complaining about anything from 3.7 to 4.0GHz as being too close to the frequency of their radio altimeters, which run at 4.2 to 4.4GHz. But that’s not the only mid-band frequency we’re using! T-Mobile’s “ultra capacity” 5G network runs on channels of up to 100MHz of (Opens in a new window)2.5GHz. AT&T and Verizon just introduced new mid-band networks based on the “C-band,” at 3.7 to 3.8GHz. Later this year, AT&T, T-Mobile, and Dish will all turn on more coverage at 3.45 to 3.55GHz. If your phone’s status indicator says “5G UC,” “5G UW,” or “5G+,” you are on mid-band or high-band. There’s no easy way to tell the difference between mid-band and high-band on your phone.

On this T-Mobile coverage map, the darkest color is mid-band 5G.

High-band 5G, or millimeter-wave, is the really new stuff. So far, this is mostly airwaves in the 20-100GHz range. These airwaves haven’t been used for consumer applications before. They’re very short range; our tests have shown about 800-foot distances from towers. But there’s vast amounts of unused spectrum up there, which means very fast speeds using up to 800MHz at a time. We’ve seen speeds over 3Gbps on Verizon’s high-band network, which it calls “ultra wideband.” Unfortunately, we found in our Fastest Mobile Networks 2021 tests that Verizon’s network only showed around 3% coverage in the cities we surveyed. AT&T and T-Mobile also have some high-band. They generally describe it as only for high-density hotspots, like college campuses and football stadiums.

T-Mobile describes the three forms of 5G as a “layer cake.”

High bands have been used before for backhaul, connecting base stations to remote internet links. But they haven’t been used for consumer devices before, because the handheld processing power and miniaturized antennas weren’t available. Millimeter-wave signals also drop off faster with distance than lower-frequency signals do, and the massive amount of data they transfer will require more connections to landline internet. So cellular providers use many smaller, lower-power base stations (generally outputting 2–10 watts) rather than fewer, more powerful macrocells (which output 20–40 watts) to offer the multi-gigabit speeds that millimeter-wave networks promise. Because of the very fast drop-off, the waves are quite weak when they get to you.

This neighborhood test shows how high-band 5G currently has about an 800-foot range.

In many major cities, the carriers installed these “small cells” to increase 4G capacity starting in 2017. In those cities, they just need to bolt an extra radio onto the existing site to make it 5G. There’s a struggle going on elsewhere, though, where carriers are having trouble convincing towns to let them add small cells to suburban neighborhoods. That’s similar to previous struggles over establishing cellular service at all in many of these towns. 

Verizon is trying to enhance its high-band 5G coverage by making deals with companies that create 5G extenders and repeaters, such as Pivotal Commware.

Where Is 5G Available?

5G is now “nationwide,” although with the carrier’s very different approaches to it, you’re going to have different experiences in different places.

Verizon has a slower “nationwide” 5G based on shared 4G channels, mid-band 5G in 46 metro areas, and fast, high-band 5G in more than 60 cities, with online coverage maps here(Opens in a new window). Verizon’s coverage map merges mid-band and high-band using the same color. Almost all of that coverage is mid-band. Verizon calls its mid and high bands “5G UW,” or “ultra wideband.”

T-Mobile currently has nationwide low-band 5G and faster mid-band 5G that covers most of the nation’s population, with a coverage finder here(Opens in a new window), and some limited high-band that I haven’t been able to find a recent coverage update for. It calls its mid and high bands “5G UC,” or “5G ultra capacity.”

AT&T has slow low-band across much of the country, mid-band in a handful of cities, and high-band in a range of “venues” such as stadiums and campuses. It calls the low-band “5G” and the mid and high-band “5G+.” The company has low-band maps and a high-band venue list here(Opens in a new window).

Verizon 5G is fast, if you can find it.

Which 5G Phones Are Coming Out?

5G phones are mainstream now; expect any phone over $300 to support it. Here’s a list of Verizon phones supporting mid-band 5G. AT&T has a similar list but adds the Galaxy A13 5G. All T-Mobile 5G phones support mid-band.

Low- and mid-band 5G is less expensive to implement than high-band 5G, so many AT&T and T-Mobile phones lack high-band 5G. I’m of two minds about whether or not that matters. More technology is better, and the companies do own a lot of high-band airwaves. But they’ve been extremely reticent about what they plan to do with them, so it’s unclear what advantage high-band will bring you in AT&T and T-Mobile phones. If you want to dot all your i’s, the OnePlus 9 Pro; the Galaxy S21 and S22 series; the Galaxy Z Flip3 and Fold3; the Galaxy Note 20 Ultra; the iPhone 12 and 13 series; the Pixel 5; and the Verizon and AT&T models of the Pixel 6 and 6 Pro all have high-band.

You can check out our current rundown of the best 5G phones (and see the chart below) for more.

Other countries have even more 5G phones, with models from Huawei, Oppo, Realme, Xiaomi, and others. They generally don’t work on US 5G networks because they don’t support our frequency bands; they use European and Asian mid-band systems we don’t have here.

Is 5G Safe?

Yes. Online conspiracy theories have blamed 5G for everything from cancer to coronavirus, but they tend to fall apart at the slightest tap of actual facts. Low-band and mid-band 5G are based on radio frequencies that have been used for decades. Low-band 5G uses UHF TV bands, which have been in use since 1952. Sprint’s mid-band has been in use at least since 2007; parts of it were first used in 1963.

The airline industry has raised recent concerns about AT&T’s and Verizon’s new C-band networks, saying the frequencies are too close to those used by radio altimeters, which judge airplanes’ distance from the ground. There is 400MHz between the cellular networks, at 3.7 to 3.8GHz, and the altimeters, at 4.2 to 4.4GHz, but some altimeter models lack filters to block signals on other channels. The FAA and FCC have been working out compromises to deal with this issue, including certifying altimeter models with filters and putting “exclusion zones” with no C-band near airport approaches.

The greatest 5G worries in the US tend to be around high-band, or millimeter-wave, 5G. This is the short-range type that requires a lot of small cell sites, so the infrastructure is more visible than it was before. The ironic thing about worrying that millimeter-wave will fry your cells isn’t that it’s too strong, but that it’s too weak: It’s blocked by leaves, walls, glass, cars, clothing, and skin. 

5G has become a common topic of conspiracy theories.
(Photo: Sascha Segan)

Power levels are extremely important. Bluetooth and microwave ovens run on the same frequency. Because millimeter-wave signals are technically called microwave, some people are convinced they are literal microwave ovens that will fry us. But a firefly isn’t a blowtorch, and the 5G systems are more on the firefly end of things.

Studies of mmWave(Opens in a new window) have shown that it doesn’t penetrate human skin well and that its strongest effect, at levels of power higher than any 5G network uses, is that it makes things slightly warmer. At the levels 5G networks use, there’s no perceptible effect on people.

Here’s our full story on why 5G is safe.

What’s 5G For?

The first major 5G application is home internet. Both T-Mobile and Verizon are selling home internet services based on their mid-band and high-band 5G networks. Home subscribers typically use hundreds of gigabytes per month(Opens in a new window), more than our 4G networks are designed to handle. The 5G networks have enough capacity to handle that demand.

5G home internet is easier for carriers to roll out than house-by-house fiber optic lines. Rather than digging up every street, carriers just have to install fiber optics to a cell site every few blocks and then give customers wireless modems. We have a review of T-Mobile’s 5G home internet service, which so far is better than DSL, but not as good as fiber.

But home internet isn’t new. The truly new applications are waiting for widespread 5G coverage that’s noticeably faster than 4G, and the hold-up on AT&T and Verizon mid-band means we just haven’t gotten there yet.

Remotely piloting robots and drones is another 5G use we’re starting to see. Because 5G has lower latency than 4G, remote pilots can control vehicles from a distance without lag, and because 5G has more bandwidth, they can get reliable multi-camera video feeds from vehicles to see where they’re going. In Toronto, Tiny Mile delivery robots(Opens in a new window) are delivering snacks piloted by Bell’s 5G network.

Verizon has shown remote-piloted drones playing roles in industry, agriculture, and firefighting, using 5G to send back video and sensor data.

This will also end up being a key element in self-driving vehicles. Self-driving cars will interact with smart roads, traffic lights, and other vehicles, and may have to offload some of their processing power to larger, nearby computers—all of this only works fast enough to prevent collisions if you’re on a low-latency 5G network, not on 4G.

While the cars are all exchanging very small packets of information, they need to do so almost instantly. That’s where 5G’s sub-one-millisecond latency comes into play, when a packet of data shoots directly between two cars or bounces from a car to a small cell on a lamppost to another car. (One light-millisecond is about 186 miles, so most of that 1ms latency is still processing time.)

Driverless cars might need 5G.

In terms of media and gaming, don’t think about 500Mbps, think about what you can do if you have a reliable 100Mbps. In that case, 5G is about raising the minimum connection speed to allow for multiple high-quality streams and quickly switching between cameras with low latency.

Verizon has shown an NFL experience where viewers can switch between seven high-quality camera views during a game. Bell, in Canada, has put dozens of cameras around a hockey arena to let you pivot through a smooth 360-degree view of the action.

People on-site in those arenas will especially benefit from 5G because it can handle more connections at the same time as 4G. In crowded areas, such as concerts, sports games, and parades (if we ever get back to any of those), a 5G network won’t “choke up” the way a 4G network will.

There’s some talk of 5G playing a role in augmented reality and the “metaverse.” The idea is that if you’re going to be wearing AR glasses outdoors, seeing business ratings pop up over the front doors of restaurants and talking to the holographic ghosts of people walking next to you, you’re going to need the low latency and reliable speed 5G offers.

But I’d also like to emphasize that we don’t know what the big 5G application will be. When 2G came around, many analysts thought clear voice calling would be its big driver, but text messaging turned out to be the big new business. 4G was introduced with laptop modems, but it turned out to be really about phones uploading and downloading video. Once high-quality 5G is truly widespread, unexpected new applications are sure to appear.

To stay up to date with 5G, sign up for our weekly newsletter. And if you’re looking to the future, read our 6G explainer to stay ahead of the curve.

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