The future depends on connectivity. From artificial intelligence and self-driving cars to telemedicine and mixed reality to as yet undreamt technologies, all the things we hope will make our lives easier, safer, and healthier will require high-speed, always-on internet connections.


  • The Spectrum
    All radio wave frequencies, from the lowest frequencies (3 kHz) to the highest (300 GHz). The FCC regulates who can use which ranges, or bands, of frequencies to prevent users from interfering with each other’s signals.

  • Low-Band Frequencies
    Bands below 1 GHz traditionally used by broadcast radio and television as well as mobile networks; they easily cover large distances and travel through walls, but those are now so crowded that carriers are turning to the higher range of the spectrum.

  • Mid-Band Spectrum
    The range of the wireless spectrum from 1 GHz to 6 GHz, used by Bluetooth, Wi-Fi, mobile networks, and many other applications. It’s attractive to carriers because it offers lots of bandwidth while presenting fewer challenges than the millimeter wave range of the spectrum. The catch is that the FCC needs to open more of this spectrum to carriers.

  • Millimeter Wave
    The range of the wireless spectrum above either 24 GHz or 30 GHz, depending on whom you ask. There’s plenty of bandwidth on this relatively uncrowded chunk of the spectrum, which means carriers can achieve much faster speeds. But millimeter wave signals are less reliable at long distances.

  • Unlicensed Spectrum
    Spectrum not licensed to a particular carrier, such as the ranges now used for home Wi-Fi. Carriers plan to augment their licensed spectrum with service delivered over unlicensed bands.

  • Latency
    How long it takes a device to respond to other devices over a network. Faster response time is a big promise of 5G, which could be critical for things like emergency alert systems or self-driving cars.

  • Network Slicing
    The practice of creating “virtual networks” on one carrier’s infrastructure, each with different properties. For example, cars may connect to a virtual network that makes minimizing latency a priority, while smartphones may connect to a network optimized for streaming video.

  • Flexible Numerology
    The ability to assign smaller amounts of bandwidth to devices that don’t need much, such as sensors. It’s not related to the idea that numbers possess mystical meanings, but it can sound similarly arcane.

To keep up with the explosion of new connected gadgets and vehicles, not to mention the deluge of streaming video, the mobile industry is working on something called 5G—so named because it’s the fifth generation of wireless networking technology.

The promise is that 5G will bring speeds of around 10 gigabits per second to your phone. That’s more than 600 times faster than the typical 4G speeds on today’s mobile phones, and 10 times faster than Google Fiber’s standard home broadband service—fast enough to download a 4K high-definition movie in 25 seconds, or to stream several at the same time.

Eventually anyway. US carriers promise that 5G will be available nationwide by 2020, but the first 5G networks won’t be nearly so fast. 5G isn’t a single technology or standard, but rather a constellation of different technologies, and deploying them could require a radically different approach than building 4G networks. Carriers have launched demos and pilot programs that demonstrate big leaps in wireless performance, but mobile networks based on the “millimeter wave” technology that may deliver the fastest speeds probably won’t be widely available for years.

In the meantime, companies will likely build 5G networks based on other technologies that are faster than today’s networks, but can largely rely on existing infrastructure.

But there’s more to 5G than just speed; 5G technologies should also be able to serve a great many devices nearly in real time. That will be crucial as the number of internet connected cars, environmental sensors, thermostats, and other gadgets accelerates in coming years.

A lot is riding on the deployment of 5G in America. Industry experts and political leaders across the spectrum warn that it’s possible for US companies to fall behind the curve if China or some other country is able to build the foundations for 5G more quickly. To reach the goal of nationwide 5G by 2020, the government must open more wireless spectrum to carriers; the carriers must rapidly expand their infrastructure; and hardware makers need to create a new generation of devices ready to ride the 5G waves.

How We Got From 1G to 5G

The first generation of mobile wireless networks, built in the late 1970s and 1980s, was analog. Voices were carried over radio waves unencrypted, and anyone could listen in on conversations using off-the-shelf components. The second generation, built in the 1990s, was digital—which made it possible to encrypt calls, make more efficient use of the wireless spectrum, and deliver data transfers on par with dialup internet or, later, early DSL services. The third generation gave digital networks a bandwidth boost and ushered in the smartphone revolution.

(The wireless spectrum refers to the entire range of different radio wave frequencies, from the lowest frequencies to the highest. The FCC regulates who can use what which ranges, or “bands,” of frequencies and for what purposes, to prevent different users from interfering with each other’s signals. Mobile networks have traditionally relied mostly on low- and mid-band frequencies that can easily cover large distances and travel through walls. But those are now so crowded that carriers are turning to the higher range of the spectrum.)

The first 3G networks were built in the early 2000s, but they were slow to spread across the US. It’s easy to forget that when the original iPhone was released in 2007 it didn’t even support full 3G speeds, let alone 4G. At the time, Finnish company Nokia was still the world’s largest handset manufacturer, thanks in large part to Europe’s leadership in the deployment and adoption of 2G. Meanwhile, Japan was well ahead of the US in both 3G coverage and mobile internet use.

But not long after the first 3G-capable iPhones began sliding into pockets in July 2008, the US app economy started in earnest. Apple had only just launched the App Store that month, and the first phones using Google’s Android operating system started shipping in the US a few months later. Soon smartphones, once seen as a luxury item, were considered necessities, as Apple and Google popularized the gadgets and Facebook gave people a reason to stay glued to their devices. Pushed by Apple and Google and apps like Facebook, the US led the way in shifting to 4G, leading to huge job and innovation growth as carriers expanded and upgraded their networks. Meanwhile, Nokia and Japanese handset makers lost market share at home and abroad as US companies set the agenda for the app economy.

Carriers around the world already have begun building test networks for 5G, even though the core specifications for the technology, begun in 2011, were only just completed in June 2018. Yet it can be hard to suss out what’s actually being tested. For example, last year AT&T announced it would roll out something called “5G Evolution” in 20 cities, but critics called this 5G branding deceptive because the technologies AT&T uses for these networks are actually 4G technologies that rival carrier T-Mobile was already using.

At the same time, carriers including AT&T are now testing high-speed “millimeter wave” networks. And even though today’s phones can’t connect to 5G networks, consumers are finally getting a chance to try 5G thanks to offerings like Verizon’s “5G Home” service, which offers fixed wireless, as opposed to mobile wireless, for home broadband.

The Future of 5G

Carriers, gadget makers, and politicians from across the political spectrum worry that what happened to the mobile industries in Europe and Japan could happen in the US if the nation is too slow in rolling out 5G.

The US is particularly worried about China, as evidenced by a National Security Council document leaked in January 2018 proposing the creation of a nationalized 5G network to supplement the private sector. The fear is that if China is first to 5G, its burgeoning tech industry will create the next global mobile platform; 5G could also give China an edge in the AI race. More devices connected to networks would mean more data. More data with which to train algorithms could mean better AI applications.

To build 5G networks faster, the wireless industry argues that it needs permission to use more wireless frequencies, and face fewer regulations governing the building of infrastructure. The idea most commonly associated with 5G is millimeter wave technology, which takes advantage of the very high end of the wireless spectrum, where there’s plenty of unused bandwidth. It’s this technology that could enable those 10 Gbps speeds, but it comes with a huge trade-off. Millimeter wave signals are less reliable over long distances and are easily disrupted by obstacles like trees, people, and even rain. To make it practical for mobile use, carriers will need to deploy huge numbers of small access points in cities, instead of relying on a few big cell towers as they do today.

Millimeter wave access points could wind up being as small as smoke detectors, but they’ll need to be practically everywhere. Carriers may need 15- or 20-millimeter wave access points to cover an urban area currently covered by only two or three modern cell phone towers, according to a McKinsey report. Just like your Wi-Fi router at home, those access points will need to be connected to wired networks. Deploying all these extra access points and connecting them to the internet will be expensive and time consuming.

To offset those costs, the wireless industry is looking into technical fixes. For example, the Telecom Infrastructure Project, which includes Facebook and a number of telecommunications firms, is working on an antenna called Terragraph, which would let wireless access points connect with each other instead of relying exclusively on wired connections for backhaul.

One independent study of Verizon’s pilot 5G network in Houston found that millimeter waves proved more resilient than expected, but nationwide millimeter wave networks will probably take years to build. So carriers around the world are now turning to what’s known as the “mid-band” of the wireless spectrum, which includes many of the frequencies used by Wi-Fi routers and some mobile phone networks. It’s not quite as fast as the high end of the spectrum, because there’s less bandwidth available, but signals can travel farther and more reliably, making it possible to blanket areas with coverage using large towers.

The FCC has approved proposals that would allow carriers to use some mid-band spectrum currently used for military radar and satellite communications, but the US lags behind South Korea, which has already begun auctioning mid-band spectrum; and behind China, which has reserved large swaths of mid-band spectrum for 5G.

The regulator also plans on auctioning more high-band spectrum and is moving forward on proposals to auction mid-band spectrum. But it can take months or years for carriers to go from buying a license to use spectrum to actually using that spectrum, according to Recon Analytics, because of the time it takes to upgrade existing cell towers. That process involves not just physical labor but often permits from state or local governments.

Consumer advocates worry that the rush to 5G is undermining public oversight of the wireless industry. For example, the FCC gutted its net neutrality protections in 2017, dubiously arguing that fewer regulations would lead to more investment in 5G and other broadband infrastructure. In 2018, it voted to override state and local regulations governing the placement of wireless equipment in the name of helping carriers build 5G networks faster. Meanwhile, T-Mobile and Sprint are pushing regulators to approve the merger between the two companies by arguing that they would be able to deploy 5G more quickly and efficiently together.

Less oversight and fewer carriers could translate into higher prices and less availability for 5G. Harold Feld, vice president of the consumer group Public Knowledge warns that without oversight, carriers might opt not to build 5G networks in low income or rural areas that could prove less profitable.

Even if 5G were available immediately, few if any devices on the market could take advantage of it. The Chinese-made Mi Mix 3 smartphone and Motorola’s 5G Moto Mod, from the Chinese-owned company Lenovo, are expected to ship in 2019. Apple isn’t expected to release a 5G capable phone until 2020.

So 5G still feels distant. But the pieces are coming together.

Learn More

  • The Next Generation of Wireless — “5G” — Is All Hype
    A deep dive on the limitations of the millimeter wave spectrum and why we need more fiber in the ground to power the 5G future.

  • Does It Matter If China Beats the US to Build a 5G Network?
    Apple and Google dominate the smartphone landscape despite Europe beating the US to 2G and Japan beating the US to 3G. So why does it matter if China gets to 5G first? It has a lot to do with China’s size, and the amount of data that can be harvested from 5G devices.

  • Fear of China Scuttles Deal That Didn’t Involve China
    How scared are US leaders of falling behind China? Scared enough that the Trump administration blocked Singapore-based chipmaker Broadcom from acquiring US chipmaker Qualcomm, out of concerns that the combined company wouldn’t invest enough to compete with Chinese companies like Huawei in the wireless chip market.

  • Why America Needs a Nationalized 5G Network
    In early 2018, a leaked National Security Council document suggested that the US government set up a nationalized 5G network. Leaders across the political spectrum panned the idea, but a government-backed buildout of the fiber optic networks necessary for both 5G and broadband networks just might be a good idea.

  • Facebook’s Massive New Antennas Can Beam Internet for Miles
    You probably heard about Facebook’s wild plans to build drones, satellites, and lasers to blanket the world in wireless internet connectivity. But Facebook doesn’t want to be a telco. Instead, it’s working with carriers and networking gear makers to create the technology that will make 5G a reality.

  • After Slurping Up AI Researchers, Facebook Offers to Share
    The data generated by 5G networks could help train the next generation of AI applications. But AI is also useful in building 5G networks in the first place. The problem for carriers, though, is that much of the world’s AI talent works for tech giants. Facebook is trying to help by open sourcing its AI know-how.

Last updated December 12, 2018

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