For several years now, telecom networks worldwide have made 5G out to be a technological miracle. Blistering fast speeds would enable remote-operated surgeries, field applications for virtual reality and drones, and so much more. Your impressions of it, however, will depend on where you live and which phone you have.

So, what's 5G, anyway? We'll try to make sense of it for you.

What is 5G?

If you can believe it, 5G is built upon half a century's worth of advancements dating back to the first mobile phone call in 1973. Analog systems have turned digital over time and, importantly for our context, full-data connections to the internet joined text and call services. To get to the internet, your phone must be listening to and talking with a local cell site that is managing similar conversations with other user devices simultaneously. That cell site may be one in a series of district or regional nodes handling various traffic management roles and passing operations off to the next point. Eventually, the traffic gets to a backhaul which makes the connection to the hardwired internet.

Regarding each level of the process, there are technologies involved that have seen iteration over multiple generations. Second-generation protocols begat the ones in 3G, which itself begat 4G. 5G builds on top of the bundle of technologies and standards encapsulated in 4G called LTE (Long Term Evolution) and applies them across an expanded range of airwaves. The results should be greater network capacity at any particular cell site, faster speeds, and lower latency in all areas with superlative performance for those that can latch onto the high-end spectrum.

We'll focus on the relationship between your phone, tablet, or home internet modem and the tower onto which it latches.

The bands and brands of 5G

The wireless connection between your phone and the tower will have different characteristics based on various factors, but the biggest one by far is which frequency band facilitates it. As we said above, higher frequencies have a speed advantage, while lower frequencies can propagate across longer distances and even through obstacles like people and walls.

There are two key ranges that the mobile industry talks about. Here's what you need to know about them:

Millimeter wave

The name "millimeter wave" or mmWave refers to the wavelengths in this range generally nearing 1mm.

These incredibly potent frequency bands have produced multi-gigabit speeds in tests conducted by the telecoms though you'll more likely see speeds on either side of 1Gbps on any given day. That said, because of their limited propagation capabilities, they're considered the best fit for central business districts and entertainment and sports venues.

You'll find mmWave 5G services in, among other places, the United States and Australia with some enhanced branding like "5G+," "5G Max," or "5G Ultra Wideband." Networks in the United Kingdom have yet to dip into this range, but Light Reading reports that Ofcom is running through the process of auctioning off rights to that spectrum.

The 3rd Generation Partnership Project (3GPP), the standards developing committee for the entire wireless trade, has defined seven frequency bands for public use in the mmWave space. They are designated with Band numbers n257 through n263 and run anywhere from 24GHz all the way up to 71GHz. You'll find the most international support for bands n257 and n258 if you have an unlocked device. U.S. networks are pretty much the only ones running on n260, n261, and n262.

Sub-6GHz

This catch-all term refers to nearly all the existing airspace that's been used by wireless networks thus far. Much of this spectrum has had to be "refarmed," a convoluted process that involves shutting down 2G, 3G, and even some 4G services and configuring equipment to run on different subsections of the spectrum to run 5G service.

In the United States, the three major carriers - AT&T, T-Mobile, and Verizon - have all shut down their 2G and 3G sites as of the end of 2022. Refarming is still in progress in the United Kingdom, but enough space has been cleared to allow for sub-6GHz 5G service to run in the country. Vodafone is shutting off 3G in 2023.

Band numbers run from n1 to n105 - though only a small selection is in use in any given country - with frequencies spanning from 600MHz (if you're curious, this produces a wavelength of about 50cm) to just over 6GHz. Most bands share the same numerical band designations, and general frequency ranges they had for the 4G LTE standard. All that's changed for 5G with each band's new "n" prefix. Most operators plainly call this service "5G," though marketing names are used, such as T-Mobile's 5G UC, Verizon's 5G UW, and AT&T's 5G+.

In the US, AT&T uses n5 and n77 for its Sub-6GHz 5G. Verizon runs n2, n5, n77, and n66 while T-Mobile uses n41 and n71. If you're unsure whether your phone supports 5G, check to see if it supports those key bands.

Download speeds will vary more widely in the sub-6 spectrum range, but again, you'll find that maximum potential is positively correlated to frequency. You can expect anywhere as low as 30-70Mbps on a 600MHz connection going to 100-500Mbps with 2.5GHz.

Fake it until you make it: the 5G story

Telecoms were braced for a multi-year deployment to get all-new 5G equipment to their entire service areas. This meant being able to deliver on the core backend technologies of 5G while still using cell site equipment for 4G. The 3GPP decided to codify aspects for a stopgap form of 5G with a so-called Non Standalone (NSA) standard.

NSA networks allow towers to pick up and manage connections using 4G protocols while bringing some of the more efficient processes introduced with 5G. Concepts like Dynamic Spectrum Sharing helped existing cell networks handle throughput coming from and moving to the few customers with new 5G phones in the nascent days while maintaining the performance that other subscribers expect from their 4G service. Operators also had the leeway to mislead consumers about whether they badged a cell connection as "4G" or "5G" at any given time - I covered this in a 2019 article for our sister site, Android Police.

As more users on-ramped to 5G devices and even 5G home internet services, telecoms could turn on fresh equipment to run Standalone networks using all the 5G protocols to their advantage.

What are the benefits of 5G?

You may have seen some of the killer applications that wireless trade titans like Qualcomm have touted. 5G will enable enormous real-time data-tracking capacity that will allow autonomous vehicles to constantly be aware of each other as they navigate at highway speeds. It'll open up a pipeline for sugar-fine graphic detail while you're wearing your AR headset and checking in on a construction site.

This imagined world, though, requires other facets of research and development to get up to speed as well. More importantly, the very nature of wireless connectivity will ensure that the benefits will be concentrated in certain areas and lacking in others. And even if you're standing right under the best mmWave or Sub-6GHz 5G site, you probably don't have an existing application that can completely use up all that speed you can access - Netflix isn't in 16K yet.

So, the benefits are nebulous and are limited for the average person right now. The biggest difference you'll see right now is a speed improvement compared to 4G, which is still nice to have.

5G in the US

AT&T, T-Mobile, and Verizon all run 5G services in the sub-6 and mmWave bands. AT&T and Verizon launched their mmWave networks first in 2019 while T-Mobile (along with its soon-to-be merger partner Sprint at the time) followed up the next year with sub-6. Over time, all three have put up towers broadcasting on frequencies in both ranges.

US Cellular, a smaller super-regional player in the market, is currently operating a sub-6 5G network for mobile users and a mmWave home internet service in select markets.

Dish, which is still best known for satellite TV, has also gotten into the game, having bought prepaid carrier Boost Mobile from the combined Sprint/T-Mobile entity. It owns licenses in the sub-6 and mmWave ranges but only operates its burgeoning 5G service on the former.

5G in the UK

Three, EE, O2, and Vodafone all operate active sub-6GHz 5G networks, with each claiming hundreds of cities, towns, and villages covered. EE was the first to go live in 2019, but the others quickly followed.

It's difficult to get an accurate sense of how wide each network's coverage is, but according to mapped crowdsourced data from nPerf, Three leads the pack, followed by EE, O2, and Vodafone.

You might be able to see why, then, Vodafone and O2 parent Telefónica have an agreement in place to build out shared network infrastructure, including for 5G, across the country.