What Is 5G?

What Is 5G?

AT&T, Verizon, and other carriers are starting to launch 5G networks this year. But what exactly is 5G, and how fast is it compared with 4G? Here are the facts we know so far.

5G Is (Barely) Real

The first wave of 5G has just arrived. On April 3, Verizon started selling the world’s first 5G phone, the Moto Z3 with its attached Moto Mod. AT&T, meanwhile, has been quietly running trials of a 5G hotspot with businesses in 19 cities, getting ready for broader commercial availability later this spring.

We tested both of those systems to see what the early 5G experience is like. And you have to remember: It’s early. Verizon’s 5G in Chicago, right now, only covers parts of downtown and seems to get about 300 feet of distance from each cell site. AT&T’s 5G in Dallas gave us 1.3Gbps speeds and about 600 feet of range—but only at two locations in the city. Neither system can do uploads on 5G yet, and neither has the low latency 5G promises. They’re the first step in many.

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 sorts of 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 widespread in the US around 2013.

So following that plan, while we’re getting a little bit of 5G right now, you should expect the big 5G applications to crop up around 2021 or 2022. Until then, things are going to be confusing as wireless carriers jockey for customers and mind share.

5G stands for fifth-generation cellular wireless, and the initial standards for it were set at the end of 2017. But a standard doesn’t mean that all 5G will work the same—or that we even know what applications 5G will enable. There will be slow but responsive 5G, and fast 5G with limited coverage. Let us take you down the 5G rabbit hole to give you a picture of what the upcoming 5G world will be like.

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?

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 make 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: greater speed (to move more data), lower latency (to be more responsive), and the ability to connect a lot more devices at once (for sensors and smart devices).

The actual 5G radio system, known as 5G-NR, isn’t compatible with 4G. But all 5G devices in the US, to start, will need 4G because they’ll lean on it to make initial connections before trading up to 5G where it’s available. That’s technically known as a “non standalone,” or NSA, network. Later, our 5G networks will become “standalone,” or SA, not requiring 4G coverage to work. But that’s a few years off.

4G will continue to improve with time, as well. The Qualcomm X24 modem, which will be built into most 2019 Android flagship phones, will support 4G speeds up to 2Gbps. The real advantages of 5G will come in massive capacity and low latency, beyond the levels 4G technologies can achieve.

That symbiosis between 4G and 5G has caused AT&T to get a little 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.

5G map
The various carriers have promised 5G deployments in cities around the country. This map shows some of the announced locations.

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

The new system is also designed to operate on much larger channels than 4G is, to carry higher speeds. While most 4G channels are 20MHz, bonded together into up to 160MHz at a time, 5G channels can be up to 100MHz, with Verizon using as much as 800MHz at a time. That’s a much broader highway, but it also requires larger, clear blocks of airwaves than were available for 4G

5G networks need to be much smarter than previous systems, as they’re juggling many more, smaller cells that can change size and shape. But even with existing macro cells, Qualcomm says 5G will be able to boost capacity by four times over current systems by leveraging wider bandwidths and advanced antenna technologies.

The goal is to have far higher speeds available, and far higher capacity per sector, at far lower latency than 4G. The standards bodies involved are aiming at 20Gbps speeds and 1ms latency, at which point very interesting things begin to happen.

What’s the Frequency?

5G primarily runs in two kinds of airwaves: below and above 6GHz.

Low-frequency 5G networks, which use existing cellular and Wi-Fi bands, take advantage of more flexible encoding and bigger channel sizes to achieve speeds 25 to 50 percent better than LTE, according to a presentation by T-Mobile exec Karri Kuoppamaki. Those networks can cover the same distances as existing cellular networks and generally won’t need additional cell sites. Sprint, for example, is setting up all of its new 4G cell sites as 5G-ready, and it’ll just flip the switch when the rest of its network is prepared.

Rural networks will likely stick with low-band 5G, because low-frequency bands have great range from towers.

To get super-high, multi-gigabit speeds, carriers are first turning to newer, much higher frequencies, known as millimeter wave. Down in the existing cellular bands, only relatively narrow channels are available because that spectrum is so busy and heavily used. But up at 28GHz and 39GHz, there are big, broad swathes of spectrum available to create big channels for very high speeds.

Those 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 will have to 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.

Fortunately for them, the carriers have already installed those “small cells” in many major cities, to increase capacity during the 4G era. (From my office window in New York, I can see several small cell sites.) 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. For what it’s worth, small cells tend to be much less powerful than the macrocells used for 2G through 4G cellular systems: 2-20 watts as compared with 20-40 watts for macrocells.

There’s a third set of airwaves being used overseas, which might be a sweet spot: mid-band. These frequencies, ranging from 3.5GHz to 7GHz, are slightly above current cellular bands but have quantities of spectrum (and speeds) that start to look like millimeter wave. The US is falling behind other countries in mid-band spectrum because over here, it’s currently being used by a mishmash of organizations including satellite companies and the Navy, but there are some efforts to free it up.

Mid-band networks won’t require quite as many cell sites as millimeter wave, although they’d still be pretty dense; probably every third to half-mile.

Who’s Launching 5G When?

AT&T launched 5G in 12 cities on December 21, 2018 with one mobile internet hotspot, the Netgear Nighthawk 5G. It raised its city count to 19 in April. AT&T seems to be only giving out a few hotspots per city, and covering a few neighborhoods in each city. It’s offering service for free right now. I expect AT&T will have retail service plans and coverage maps, along with its first 5G phone, the Samsung Galaxy S10 5G, in mid-June.

AT&T is using 39GHz spectrum for its initial rollout, followed by some 28GHz, and then low band, former 3G spectrum later in the year.

Verizon started out with a fixed 5G home internet service in a few neighborhoods of four cities. That was followed by the Moto Z3 phone in Chicago and Minneapolis on April 3, and I expect the Samsung Galaxy S10 5G will come to Verizon on May 16. Verizon’s 5G service plans cost $10 more than its unlimited 4G plans, for truly unlimited 5G data with no deprioritization. The carrier is mostly using 28GHz spectrum.

Sprint’s 5G will be on the 2.5GHz band, which will give it similar coverage to Sprint’s existing 4G LTE network; in fact, it will use the same cell sites. Sprint will launch its first four 5G cities in May, followed by five more in June. Unlike the other carriers, it has released initial coverage maps, and they cover much broader parts of cities than the other carriers have covered so far. Sprint promises speeds of 400-600Mbps, but we’ll see.

T-Mobile is building a nationwide 5G network on the 600MHz and 28GHz bands starting some point in 2019, with full national coverage by 2020. It may also get the Galaxy S10 5G in June.

The speed of a wireless network is tied to how much spectrum you can use for it. Because T-Mobile is only using an average of 31MHz of spectrum at 600MHz as opposed to the hundreds of MHz that millimeter wave networks will use, its low-band 5G network will be a little bit faster than 4G, but not multiple gigabits fast. It will still have the low latency and many connections aspects of 5G, making it usable for gaming, self-driving cars, and smart cities, for instance. In cities, the millimeter wave network will be super fast.

“Are we going to see average speeds start to move up by tens of megabits per second? For sure,” T-Mobile CTO Neville Ray said. “We would love to see average speeds triple, or move to 100Mbps, but that’s a journey that’s going to take time in the industry.”

Which 5G Phones Are Coming Out?

The first round of 5G phones will only support some of the 5G systems being used in the US. They will not support low-band, FDD networks, such as T-Mobile’s 600MHz and AT&T’s old 3G spectrum. So if broad 5G coverage is more important to you than top speeds in urban areas, you may want to wait for phones that support those networks during the second half of the year.

With the Moto Z3 relying on an attachable Mod for 5G service, the Samsung Galaxy S10 5G will be the first integrated 5G phone on AT&T, T-Mobile, and Verizon. That will probably come out on May 16 for Verizon, and in June for the other carriers.

It will be followed by LG’s V50 phone for Sprint (and possibly the other carriers) and later by another Samsung flagship that will support the low-band, long-distance 5G networks. I think that one will be a Galaxy Note 10 variant.

Many other companies, including HuaweiOnePlusZTE, Oppo, Vivo, and Xiaomi, have pledged to produce 5G phones in 2019. But none of those phones appear to be destined for the US, and none of them will be compatible with US networks. It’s a big world out there.

We think there will be a 5G iPhone in 2020, but not before.

What’s 5G For?

So Verizon wants to initially use 5G as a home internet service, and everybody else is more focused on faster smartphones. Those uses are table stakes, just to get the networks built so more interesting applications can develop in the future.

5G home internet shows one major advantage over 4G: huge capacity. Carriers can’t offer competitively priced 4G home internet because there just isn’t enough capacity on 4G cell sites for the 190GB of monthly usage most homes now expect. This could really increase home internet competition in the US, where, according to a 2016 FCC report, 51 percent of Americans only have one option for 25Mbps or higher home internet service. For its part, Verizon says its 5G service will be truly unlimited.

5G home internet is also much 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. Verizon chief network officer Nicki Palmer said the home internet service would eventually be offered wherever Verizon has 5G wireless, which will give it much broader coverage than the carrier’s fiber optic FiOS service.

On a trip to Oulu, Finland, where there’s a 5G development center, we attended a 5G hackathon. The top ideas included a game streaming service; a way to do stroke rehab through VR; smart bandages that track your healing; and a way for parents to interact with babies who are stuck in incubators. All of these ideas need either the high bandwidth, low latency, or low-power-low-cost aspects of 5G.

Last year, we surveyed the 5G startups that Verizon is nurturing in New York. At the carrier’s Open Innovation Lab, we saw high-resolution wireless surveillance cameras, game streaming, and virtual reality physical therapy.

Our columnist Michael Miller thinks that 5G will be most important for industrial uses, like automating seaports and industrial robots.

Driverless cars may need 5G to really kick into action, our editor Oliver Rist explains. The first generation of driverless cars will be self-contained, but future generations will interact with other cars and smart roads to improve safety and manage traffic. Basically, everything on the road will be talking to everything else.

Honda self-driving car

To do this, you need extremely low latencies. 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.)



By |2019-06-21T14:26:04+00:00June 21st, 2019|Uncategorized|0 Comments

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