December isn't just a time for the holidays. It's a time for 5G merriment.

In early December, Qualcomm went all-in on how the next-generation wireless technology will take shape in 2019. Its chips serve as the brains of high-profile phones, such as the Google Pixel 3 and Samsung Galaxy Note 9, and it used its annual Snapdragon Tech Summit as a showcase for 5G technology, showing off a prototype phone that can tap into 5G networks. Partners AT&T and Verizon pitched in too, setting up "live networks" at the conference hotel in Maui to demonstrate their capabilities. Samsung showed off a 5G reference device at the event. 

"A lot of the work went into getting the 5G logo to show on this phone," Qualcomm President Cristiano Amon said as he held up the company's prototype during the keynote.

In mid-December, AT&T took things up a notch by launching its 5G network in 12 US cities, including Atlanta, Dallas and New Orleans, with just two weeks to spare to make its self-imposed deadline of the end of 2018. But for the moment, its restrictions aren't just geographic -- it'll work only with one specific 5G hotspot from Netgear, which will create a Wi-Fi network that phones, tablets and laptops can tap into.

For actual 5G phones, you'll have to wait until 2019. Samsung and Verizon have said they'll launch a 5G smartphone in the first half of next year. AT&T and Sprint too.

Two months back, Verizon launched a variant of 5G as a home internet service, and in early 2019 it plans to begin a standards-based mobile service.

All of this means 5G is going from years of hype -- ever since Verizon talked about moving into the area three years ago -- to becoming reality. Beyond a big speed boost, 5G has been referred to as foundational tech that will supercharge areas like self-driving cars, virtual and augmented reality and telemedicine services, such as remote surgery.  

But what exactly is 5G? Why are people so excited? The following is a breakdown of why the next generation of wireless technology is more than just a boost in speed, and why you should be excited. 

What is 5G?

It's the next (fifth) generation of cellular technology, which promises to greatly enhance the speed, coverage and responsiveness of wireless networks. How fast are we talking? Think 10 to 100 times speedier than your typical cellular connection, and even faster than anything you can get with a physical fiber-optic cable going into your house. (In optimal conditions, you'll be able to download a season's worth of Stranger Things in seconds.)

Is it just about speed?

No! One of the key benefits is something called low latency. You'll hear this term a lot. Latency is the response time between when you click on a link or start streaming a video on your phone, which sends the request up to the network, and when the network responds, delivering you the website or playing your video.

That lag time can last around 20 milliseconds with current networks. It doesn't seem like much, but with 5G, that latency gets reduced to as little as 1 millisecond, or about the time it takes for a flash on a normal camera. 

That responsiveness is critical for things like playing an intense video game in virtual reality or for a surgeon in New York to control a pair of robotic arms performing a procedure in San Francisco, though latency will still be affected by the ultimate range of the connection. The virtually lag-free connection means self-driving cars have a way to communicate with each other in real time -- assuming there's enough 5G coverage to connect those vehicles. 

How does it work?

5G initially used super high-frequency spectrum, which has shorter range but higher capacity, to deliver a massive pipe for online access. But given the range and interference issues, the carriers are starting to explore lower-frequency spectrum -- the type used in today's networks -- to help ferry 5G across greater distances and through walls and other obstructions. 

The result is that the insane speeds companies first promised won't always be there, but they'll still represent a big boost from what we get today with 4G LTE. 

Where do these carriers get the spectrum?

Some of these carriers already control small swaths of high-frequency radio airwaves, but many will have to purchase more from the government. The Federal Communications Commission is holding an auction for so-called millimeter wave spectrum, which all of the carriers are participating in. 

Are there other benefits?

The 5G network is designed to connect a far greater number of devices than a traditional cellular network. That internet of things trend you keep hearing about? 5G can power multiple devices around you, whether it's a dog collar or a refrigerator. 

The 5G network was also specifically built to handle equipment used by businesses, such as farm equipment or ATMs. Beyond speed, it's also designed to work differently on connected products that don't need a constant connection, like a sensor for fertilizer. Those kinds of low-power scanners are intended to work on the same battery for 10 years and still be able to periodically send over data. 

Sounds great, but when does 5G get here?

Verizon launched the first "5G" service in the world in October, but it's a bit of a technicality -- a fixed broadband replacement, rather than a mobile service. An installer has to put in special equipment that can pick up the 5G signals and turn that into a Wi-Fi connection in the home so your other devices can access it. 

There's also some debate about whether the service even qualifies as 5G: It doesn't use the standards the industry has agreed upon. The company wanted to jump out ahead, and used its own proprietary technology. Verizon argues that the speeds, which range from 300 megabits per second to 1 gigabit per second, qualify the service for 5G designation. Its rivals and other mobile experts dispute that claim. 

The launch was extremely limited in select neighborhoods in Los Angeles; Sacramento, California; Indianapolis; and Dallas. (Let us know if you're among the lucky few who get it.)

As of the end of December, AT&T was turning on its mobile 5G network in a dozen cities, and more specifically in "dense urban and high-traffic areas." Take note, Verizon: AT&T boasted that it's the "first and only company in the US to offer a mobile 5G device over a commercial, standards-based mobile 5G network." It plans to boost its coverage to a total of 19 cities in 2019.

Verizon says it'll launch its mobile 5G next year.

No 5G phones? Can't I just pick up 5G with my existing smartphone?

Sorry, no. 5G technology requires a specific set of antennas that aren't available yet. Sprint says it plans to release the first US 5G smartphone next year, which will be built by LG. It's also working on a 5G "smart hub" with HTC, but as with all of the 5G news so far, they've been light on details such as features, specifications, price or availability.

Many of the phones will use Qualcomm's X50 modem, which is designed specifically to tap into 5G spectrum.

Generally, 5G smartphones are expected to come out in the first half of next year. Rumors point to Samsung being among the first to build a 5G smartphone. The company reportedly will put 5G in a version of its Galaxy S10. Samsung mobile CEO DJ Koh, however, teased that a specific 5G phone will launch ahead of its flagship.

OnePlus has also said that it'll be among the first to have 5G in a phone as well, but that device won't be coming to the US. 

Anything I should worry about?

High-frequency spectrum is the key to that massive pickup in capacity and speed, but there are drawbacks. The range isn't great, especially when you have obstructions such as trees or buildings. As a result, carriers will have to deploy a lot more small cellular radios, creatively named small cells, around any areas that get a 5G signal. 

That's going to annoy anyone who doesn't want cellular radios near them. With concerns over potential health risks, as well as the possibility some people will see them as neighborhood eyesores, there may be some objections to these things. 

Carriers using low-frequency bands may get away with fewer cellular radios, but 5G will almost certainly require companies to further build out their networks. 

How broadly will 5G be available in 2019?

Here's the other concern -- 5G might still be a theoretical possibility for a lot of people. 

T-Mobile says it's launching in 30 cities next year, while Sprint will launch in nine cities. AT&T plans to have 5G in up to 19 markets next year, and Verizon aims to launch next year too, but it's unclear how wide the coverage will be. Globally, China, Japan and South Korea are racing to build out their 5G networks, with Europe behind as it takes the slow-and-steady approach. 

So don't feel like you need to rush out to buy that first 5G smartphone. Chances are, service won't be widely available until 2020 or beyond. 

Also, while some see 5G helping to improve coverage for everyone, rural areas will likely miss out for a while since it lacks the infrastructure to support all of those cell radios. 

Will it cost more?

That's a definite possibility. Says AT&T: "5G brings capabilities that are going to cause us to think different about pricing. We expect pricing to be at a premium to what we charge today,"

That echoes a comment made back in March by then-Sprint CEO Marcelo Claure, who said he saw 5G as a premium service. New CEO Michel Combes declined to comment on pricing. 

There is precedent for holding the line: LTE didn't cost anymore when it first came out -- you just needed to buy a new phone. But pricing models do change over time. Since 4G launched, the carriers both took away unlimited plans and brought them back. 

Verizon's home broadband service costs $50 for wireless subscribers, and $70 for everyone else. Those are in line with other broadband costs. (You can find out if you're eligible for the service here.)

AT&T's mobile 5G service will be free for "select" customers for the first 90 days. After that, the company will charge $499 for the hotspot plus $70 per month for a plan with a 15GB data cap.

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Our 5G glossary

Do you want to show off your 5G knowledge to your friends? Or seem like the smartest person at a party? Check out our 5G glossary below. 

5G NR 

The 5G bit is pretty obvious, but the NR stands for New Radio. You don't have to know a lot about this beyond the fact that it's the name of the standard that the entire wireless industry is rallying behind, and it just came out in December.

That's important because it means everyone is on the same page when it comes to their mobile 5G networks. Carriers like AT&T and T-Mobile are following 5G NR as they build their networks. But Verizon, which began testing 5G as a broadband replacement service before the standard was approved, isn't using the standard -- yet. The company says it'll eventually adopt 5G NR for its broadband service, and intends to use NR for its 5G mobile network.

Millimeter wave

All cellular networks use airwaves to ferry data over the air, with standard networks using spectrum in lower frequency bands like 700 megahertz. Generally, the higher the band or frequency, the higher the speed you can achieve. The consequence of higher frequency, however, is shorter range.

To achieve those crazy-high 5G speeds, you need really, really high frequency spectrum. The millimeter wave range falls between 24 gigahertz and 100 gigahertz.

The problem with super-high-frequency spectrum, besides the short range, is it's pretty finicky -- a leaf blows the wrong way and you get interference. Forget about obstacles like walls. Companies like Verizon are working on using software and broadcasting tricks to get around these problems and ensure stable connections.

Small cell

Traditional cellular coverage typically stems from gigantic towers littered with different radios and antennas. Those antennas are able to broadcast signals at a great distance, so you don't need a lot of them. Small cells are the opposite --  backpack-size radios can be hung up on street lamps, poles rooftops or other areas. They can only broadcast a 5G signal at a short range, so the idea is to have a large number of them in a densely packed network. 

Some cities have this kind of dense network in place, but if you go outside of the metro area, that's where small cells become more of a challenge. 

Sub-6GHz

Given how troublesome really high-band spectrum can be (see the "millimeter wave" section above), there's a movement to embrace spectrum at a much lower frequency, or anything lower than 6GHz. The additional benefit is that carriers can use spectrum they already own to get going on 5G networks. T-Mobile, for instance, has a swath of 600MHz spectrum it plans to use to power its 5G deployment. Prior to sub-6GHz, that would've been impossible.

That's why you're seeing more carriers embrace lower-frequency spectrum.

But lower-frequency spectrum has the opposite problem: While it reaches great distances, it doesn't have the same speed and capacity as millimeter wave spectrum.

The ideal down the line will be for carriers to use a blend of the two.

Gigabit LTE

You're hearing more about Gigabit LTE as a precursor to 5G. Ultimately it's about much higher speeds on the existing LTE network. But the work going toward building a Gigabit LTE network provides the foundation for 5G.

For more on Gigabit LTE, read our explainer here.

MIMO

An abbreviation of "multiple input, multiple output." Basically, it's the idea of shoving more antennas into our phones and on cellular towers. And you can always have more antennas. They feed into the faster Gigabit LTE network, and companies are deploying what's known as 4x4 MIMO, in which four antennas are installed in a phone.

Carrier aggregation 

Wireless carriers can take different bands of radio frequencies and bind them together so phones like the Samsung Galaxy S8 can pick and choose the speediest and least congested one available. Think of it as a three-lane highway so cars can weave in and out depending on which lane has less traffic.

QAM 

This is a term that's so highly technical, I don't even bother to explain the nuance. It stands for quadrature amplitude modulation. See? Don't even worry about it.

What you need to know is that it allows traffic to move quickly in a different way than carrier aggregation or MIMO. Remember that highway analogy? Well, with 256 QAM, you'll have big tractor trailers carrying data instead of tiny cars. MIMO, carrier aggregation and QAM are already going into 4G networks, but play an important role in 5G too.

Beam forming 

This is a way to direct 5G signals in a specific direction, potentially giving you your own specific connection. Verizon has been using beam forming for millimeter wave spectrum, getting around obstructions like walls or trees.

Unlicensed spectrum 

Cellular networks all rely on what's known as licensed spectrum, which they own and purchased from the government.

But the move to 5G comes with the recognition that there just isn't enough spectrum when it comes to maintaining wide coverage. So the carriers are moving to unlicensed spectrum, similar to the kind of free airwaves that our Wi-Fi networks ride on.

Network slicing

This is the ability to carve out individual slivers of spectrum to offer specific devices the kind of connection they need. For instance, the same cellular tower can offer a lower-power, slower connection to a sensor for a connected water meter in your home, while at the same time offering a faster, lower-latency connection to a self-driving car that's navigating in real time.

Are you hearing more 5G-related terms that confuse you? Contact us and we'll update this story with additional terms.

First published  Feb. 8. 
Updated Sept. 27, Oct. 17 and Nov. 13:: Added new details. Updated Dec. 3 and 4: Added details about the Qualcomm event. Updated Dec. 18: Added details about AT&T's 5G launch. 

5G: Your Next Big Upgrade: CNET's series on the next generation of cellular technology.

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