Raindrops splat the pavement in downtown Chicago as I balance an umbrella in the crook of my arm and phones in each hand. On my left, I'm downloading the PUBG Mobile game over Verizon's 5G network. On my right, I'm timing how long it takes to install: 2.5 minutes (versus 6 minutes on 4G). What's so exhilarating about this moment has less to do with the progress bar on my screen and more to do with bearing witness to one of the first live 5G networks anywhere in the world.

After years of hearing how 5G is poised to change our lives with lightning-fast phone download speeds, and crisp, super high-resolution video calls, AR apps, and real-time gaming that are all lag-free, 5G is finally real. But it's far from stable -- and stability is the one thing 5G desperately needs.

On its surface, 5G is about astounding speeds and almost zero latency -- the lag time between when your phone pings the network and when it responds. But on a global scale, it represents political dominance and economic might.

Nowhere is that point drawn more clearly than in President Donald Trump's increasing interest in 5G, which so far includes stopping a buyout to keep US chipmaker Qualcomm independent, signing an executive order to ban No. 1 5G infrastructure company Huawei from operating with US companies, and even pushing for 6G upgrades as quickly as possible. (6G doesn't exist yet.)

5G indicators like this one are a badge of pride for carriers hoping to sell you on their faster networks. Joshua Goldman/CNET

5G networks around the world are sprouting up as pinpricks in cities and neighborhoods, largely acting as hotspots that will give your phone some impressive juice if you're standing in just the right place with just the right device. But move a block farther, enter a building or hop into a car and that 5G connection is just as likely to revert to 4G. Or the connection might hiccup and lose its grasp on 5G on its own.

By now, my fellow CNET editors and I have gotten an extensive first-hand taste of 5G on seven networks, in 11 cities spanning Los Angeles to Seoul, with four brands of phones. We've conducted dozens of speed tests on the benchmarking app Speedtest.net and downloaded movies and apps dozens of times from services like Google Play, Netflix and Amazon Prime.

We've seen an almost two-hour movie download in 8.2 seconds, and witnessed speeds almost 20 times faster than what you might see on your 4G phone (a 5G peak of 1.8Gbps so far). But we've also seen 5G stall, lag and cut out completely as undersung and overworked techs scrambled to keep these nascent networks up and running.

The 5G age is no longer approaching. It has dawned. But slowly, and with real challenges ahead. A future where 5G conjures virtual reality worlds in front of our eyes and the instant exchange of data that makes remote medical procedures possible still feels worlds away.

At this point in the game, anyone could win the race to stable 5G first -- but some are in a better position than others.

SK Telecom's peak speeds in our downtown Seoul tests. Robert Rodriguez/CNET

Early 5G winners and losers

Everything could change as 5G development continues, but in these early days, some have pulled ahead while others have fallen behind.

South Korea, winner: While Verizon pooh-poohed South Korea's claim of being the first in the world to 5G with three carriers giving their fastest phones to six celebrities, the country's Ministry of Science and Technology reported that 1 million people signed up for 5G in 69 days, a faster rate than the country's 4G rollout.

Samsung, winner: Speaking of South Korea, the world's largest phone-maker has populated carriers worldwide with its premium Galaxy S10 5G phone, which is available on 14 networks all over the world, including the four major US carriers, as of Friday. It also sells from Samsung.com in regions that already have 5G or soon will, and through various retailers. It's one of the first, most powerful phones to work with 5G, a feather in Samsung's cap.

The Mototola 5G Mod and Galaxy S10 5G devices that tap into Verizon's 5G network both run on Qualcomm's modem. Robert Rodriguez/CNET

Qualcomm, winner: The world's largest mobile chipmaker has been talking up 5G for years, and now that it's live, the company appears to have a dominant position in the field. With the exception of Huawei, every 5G phone contains a Qualcomm chip. A gathering of dozens of carrier, handset and equipment executives on a Qualcomm stage at Mobile World Congress showed off just how critical the company is to the mobile industry.

Telstra, winner: Australia's carrier has three 5G phones -- the LG V50 ThinQ, Samsung Galaxy S10 5G, and Oppo Reno 5G -- and 10 major 5G areas: Adelaide, Perth, Sydney, Toowoomba, Launceston, Melbourne, Hobart, Gold Coast, Canberra, and Brisbane. That's impressive for a continent with a roughly 3 million square mile area -- just about the same as the contiguous United States.

Huawei, loser: Although Huawei is the world's largest maker of 5G networking equipment, the US action against the company -- a result of its alleged coziness with the Chinese government -- puts its entire business at risk.

As the US pressures other countries to follow suit, Huawei founder and CEO Ren Zhengfei said he wasn't worried about the $30 billion that Huawei might lose as a result of the US ban. The company instead doubled down on its 5G investment, though its future is up in the air. Huawei did not respond to a request for comment.

Apple, loser: The iPhone is behind the 5G curve. Unlike rivals, Apple hasn't yet announced its 5G plans. Mired in a legal battle with chipmaker Qualcomm until April, Apple was originally planning to use Intel to bring the iPhone to 5G. After the settlement, Intel immediately dropped out of the 5G game. It's been speculated that the iPhone won't get 5G until 2020. If Apple sticks to its September release cycle, it'll trail Samsung by a year and a half. The Cupertino brand may not even get its own 5G chip until 2025. Apple did not respond to a request for comment.

Confusing technology: A tale of two 5Gs

It isn't easy to wrap your head around 5G, and that's because it doesn't just mean one thing. You could have ultra-fast speeds in a tiny area or pretty-fast speeds in a wider area.

Scratch the surface and 5G, which stands for fifth-generation mobile network technology, is an insanely complicated orchestra of towers, nodes, beams and devices all using radio airwavesall at once.

It's which slice of the radio frequency, also called spectrum, a carrier will use that makes the difference in the 5G experience you get. For example, Verizon's Ultra Wideband and AT&T's Plus flavor of 5Guse millimeter wave (mmWave), which runs at an extremely high frequency that shoots powerful signal a short distance away, and not through glass or buildings. This is where you see those ultrahigh speeds.

In this model, urban centers get the fastest 5G, with outskirts on Sub-6 GHz ("mid-band") spectrum. More rural areas will get ultra-fast LTE for now. Qualcomm

On the other hand, another swath of spectrum known as "sub-6 GHz" or just "sub-6" -- the so-called midband frequencies -- to give you more coverage, though speeds won't be nearly as high. You'll see that and mmWave reflected in our peak speed results below.

In due time, some networks will join these approaches in their quest for fast, expansive 5G, even dipping into low-frequency bands to solve the problem of coverage over larger areas and through buildings. For example, T-Mobile has quietly turned on its mmWave-based 5G network now but plans to more publicly launch its next-generation service on the lower-frequency 600 MHz band in the second half of the year, when devices become available.

Our glossary of popular 5G terms will explain a lot, and here's one of the easiest to understand primers of mmWave and sub-6 to date.

AT&T's 5G test gave us the fastest results out there -- although it was a controlled environment on the set of the company's Warner Bros. studio. Robert Rodriguez/CNET

The speeds: Awe-inspiring, sometimes

We conducted scores of 5G speed tests in Chicago, Los Angeles, Dallas, London and Sydney using the Speedtst.net benchmarking app.

If you're solely looking at peak speeds, AT&T in LA easily reached the zenith, resulting in download speeds over 1.4Gbps in 8 out of 12 tests. Verizon was right behind, with a peak of 1.3Gbps down and multiple results over 1Gbps in several areas of downtown Chicago.

Sprint (Dallas), Telstra (Sydney) and EE (London and four other UK cities) used midband spectrum to achieve speeds in the 400 to 500 Mbps range, which might still be two to four times faster than your 4G phone and faster than your home Wi-Fi connection.

The progress is extremely promising in this nearly-pristine state with few real users. The real trick is for carriers to sustain these speeds once more subscribers join up and start clogging the lanes.

Global field tests: Peak 5G speeds

Peak download speed (Speedtest.net) Location 5G technology Phone Test date AT&T 1.8 Gbps Los Angeles (Warner Bros. Studio) mmWave Galaxy S10 5G June 22, 2019 Verizon 1.3 Gbps Chicago mmWave Galaxy S10 5G May 16, 2019 SK Telecom 618 Mbps Seoul Sub-6GHz Galaxy S10 5G June 27, 2019 T-Mobile 583 Mbps New York mmWave Galaxy S10 5G June 28, 2019 Telstra 489 Mbps Sydney Sub-6GHz Oppo Reno 5G June 20, 2019 Telstra 485 Mbps Sydney Sub-6GHz LG V50 June 14, 2019 Sprint 484 Mbps Dallas Sub-6GHz LG V50 May 30, 2019 EE 460 Mbps London Sub-6GHz OnePlus 7 Pro 5G June 15, 2019

The coverage: We have a long way to go

The most valuable lesson we learned from our 5G field tests is that reliable, consistentcoverage matters more than lightning speeds when it comes to a satisfying experience.

While the carriers build up 5G day by day, most of these towers and nodes are sprinkled across urban centers, which means you won't get blanketed coverage as you move throughout the day, at least not yet.

US 5G snapshot: Of the four major US carriers, Sprint had the most consistent coverage. Its use of sub-6 spectrum meant we could even run speed tests in the car, something that Verizon and AT&T's mmWave can't do. Both Verizon and AT&T offered far higher speeds, even if they largely remain elusive. Verizon has only launched in two cities but plans to be in 30 by the end of the year. T-Mobile's mmWave network didn't give us the highs we expected in congested Manhattan, but real-world download speeds were apparent.

One of our Verizon speed test results in downtown Chicago. Jessica Dolcourt/CNET

AT&T's 5G is in 19 cities but is only available to select business customers. Aside from the Warner Bros. studio where we ran our 5G speed test, we're not sure where to find AT&T's service for phones. An important note about AT&T: Its 5GE service is not true 5G, but a form of advanced 4G LTE that every other carrier also employs. In some cases, AT&T's "fake" 5G is slower than other 4G networks.

There's even more detail in our field tests -- the US 5G carrier throwdown with Verizon, AT&T, and Sprint.

UK 5G snapshot: After testing 5G in five cities (one of those on two separate days) on EE's network, the accuracy of the carrier's coverage map brought on the biggest headaches. While speeds often soundly beat the existing 4G equivalents in our tests, inconsistent coverage means you'll quickly lose the benefit of all that extra speed.

A deeper look at our 5G tests with EE from London to Edinburgh.

My colleague Andrew Hoyle found decent speeds but inconsistent coverage with UK carrier EE. Robert Rodriguez/CNET

Australia's 5G snapshot: The question of 5G is a sharp one in Australia, where onlookers wonder if the rollout could feasibly replace broadband for many. Although Australia's major network, Telstra, is off to a good start with areas of 10 5G cities covered, data caps will present a huge problem, especially on SIM cards and plans with data limits. We found they add up fast.

Read on for more on testing Telstra's 5G network with two phones.

Seoul 5G snapshot: We got the chance to run a few Speedtest.net benchmarking tests on the Galaxy S10 5G in downtown Seoul, near City Hall, courtesy of Cho Mu-Hyun, who writes for our sister site ZDNet. Results on SK Telecom's network were three to four times faster than LTE in terms of download speed and up to twice the expected upload speed.

Like the UK, Australia offered broader coverage than the US, even if the speeds weren't as high. Robert Rodriguez/CNET

Temper your expectations, and go slow

Blazing speeds, a responsive network, and extensive coverage make up 5G's Holy Grail. And while carriers want to act fast to build out their networks, the customer, should move slower. You may not have much of a choice if 5G isn't live in your area.

5G phones are just trickling in, but today's devices cost hundreds more than their 4G equivalents. For example, the Galaxy S10 Plus is $1,000 in the US, while the S10 5G comes in at $1,300 at Verizon. In a few months, a new 5G chip from Qualcomm will make these phones obsolete.

Your monthly data plan could eventually cost more, too, with Verizon temporarily waiving its plan to charge $10 more per month. Once more 5G cities come online, expect those premiums to appear in full, especially for unlimited plans.

It will be years until 5G fully replaces 4G, and as you start to become addicted to the new, faster speeds, be prepared for frustration and heartbreak when stumbling into areas with slow coverage, or when traveling to rural areas or countries where the expensive networks are still in development. Living with exponentially faster 5G speeds means you'll feel it harder when they're gone.

We have seen the birth of 5G. Now we've got to watch it grow up.

Originally published July 1, 2019 at 4 a.m. PT. Update, 3:09 p.m. PT.

Update, July 2 at 7:20 a.m. PT. Update, July 3, 2019.

