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 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.