5G 101 Guide: What It Is and What It's Not (and Why)

To truly understand the power of 5G you have to understand what 5G actually is (vs. what the vendors are telling you). Here's your technical walk-through to everything from what 5G offers in the real-world to the infrastructure underneath,.

The fifth-generation wireless networking technology popularly known as "5G" promises to deliver ultra-fast download rates, ultra-low latency, massive capacity, and vastly improved user experiences. But more than just a bigger, faster, and more efficient mobile voice and data network, 5G finally makes it practical to connect machines, objects, and devices with fiber-like speeds over the air. 5G offers a broader range of wireless services than previous generations delivered to the end user across multiple access platforms and multi-layer networks.

It's still early days for 5G, and there's a lot of confusion out there about exactly what the term means. Most people not directly connected with the technology would have a hard time giving you a clear definition. It doesn't help that the major carriers are offering different versions based on the spectrum they're using to deliver it. Keep in mind that, to get true 5G, users are going to need new mobile devices.

It's going to be hard to see clearly in the marketing blizzard that's already blowing our way, but understanding the basics of 5G will help to clear the way ahead.

5G is fast -- fast enough, for example, to allow a user to download a full-length feature movie to his/her phone in seconds. (Though The Irishman might take a little longer.)

  • 3G: 3 Mbps downloads (on stationary devices)
  • 4G: 100 Mbps downloads (theoretical max)
  • 5G: 10 Gbps downloads (theoretical max), which is 10 times faster than 4G.

5G also reduces response time significantly. By cutting "lag," 5G heralds a veritable revolution in online gaming, but also becomes essential to the success of self-driving cars and remotely operated medical devices.

  • 3G: networks typically provided response times of about 100ms
  • 4G: is currently providing response times of around 30ms
  • 5G: promises to deliver a response time as low as 1ms -- for all intents and purposes, that's an instantaneous connection to the network.

The Tech:
A 5G mobile network comprises two essential components: the Radio Access Network (RAN) and the Core Network (the Core).

The RAN is a hardware network made up of a range of devices, from small cells to towers and masts, plus dedicated in-building and home systems that connect mobile users and wireless devices to the main core network.

One component of this hardware network, the small cells, are expected to become an essential enabler of 5G—effectively the key differentiator—because they are especially useful at the new millimeter wave (mmWave) frequencies. Also known as extremely high frequency (EHF) and very high frequency (VHF), they exist between 30 GHz and 300 GHz of the spectrum. mmWaves have short wavelengths that range from 10 millimeters to 1 millimeter, which makes them useful where the connection range is very short. The small cells will take advantage of mmWave in distributed in clusters needed to provide a continuous connection and wide-area coverage.

The so-called 5G Macro Cells use MIMO (multiple input, multiple output) antennas, which multiply capacity of various signals by transmitting different signals over multiple antennas. Using multiple elements or connections makes it possible to send and receive more data simultaneously. More people can connect to the network simultaneously and maintain high throughput. The term "Massive MIMO" refers to large numbers of these antennae deployed in groups for better throughput and spectrum efficiency.

The 5G Core Network is the mobile exchange and data network that manages the mobile voice, data, and Internet connections. Where previous generations (3G, 4G) focused primarily on delivering services and information to mobile phones, the 5G Core is all about integrating with the Internet and cloud-based services, and it includes distributed servers across the network, further reducing latency. The Core is where key features of 5G will be managed—things like network function virtualization and network slicing—for different applications and services.

5G New Radio:
5G New Radio (5G NR) is a standard for the "air interface," the radio frequency portion of the circuit between the mobile device and the active base station (basically, between phone and tower). This is the standard being used to build out 5G coverage.

Developed by a collection of standards groups known as the 3rd Generation Partnership Project (3GPP), 5G NR comprises two literally named frequency ranges: Frequency Range 1 (FR1), which includes sub-6 GHz frequency bands; and Frequency Range 2 (FR2), which includes the mmWave range. The sub-6 band (Sub 6) is extremely efficient and reliable at providing connections over long distances, indoors and out. It currently runs over 2.5 GHz to 6 GHz spectrum bands.

Only one major carrier is not going to be using this standard: AT&T. Rather than 5G NR, this company is promoting its own "5G Evolution" (5Ge), which is a branding label for AT&T's LTE Advanced network. This is a powerful 4G network with MIMO support and fiber optic backhauls, but it's not really 5G.

The other major US carriers (Verizon, Sprint, T-Mobile) are claiming to deliver 5G now, but they're actually using a combination of these bands to improve their existing services. Sprint is deploying its "5G" services on its 2.5 GHz bands, the lowest of any provider at the moment. This version is unlikely to match the top speeds from the providers using mmWave: Verizon and T-Mobile. Verizon calls its deployment "Ultra Wideband." T-Mobile began using high-band 5G on 28GHz and 32GHz bands; the company launched a 600 MHz, low-band network at the end of 2019.

There's already an appetite for all this 5G goodness, and once the carriers get their networks in shape to deliver it, the uptake is likely to be a record-setter. Industry watchers expect the number of 5G subscribers to reach 1.1 billion by 2023 across the Asia-Pacific and North America regions. That would triple the number of subscribers 4G reached in the same five-year period after its launch.

About the Author

John K. Waters is the editor in chief of a number of sites, with a focus on high-end development, AI and future tech. He's been writing about cutting-edge technologies and culture of Silicon Valley for more than two decades, and he's written more than a dozen books. He also co-scripted the documentary film Silicon Valley: A 100 Year Renaissance, which aired on PBS.  He can be reached at