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ZDNET’s key takeaways
- My 5G road trip tests included rigorous testing on three Google Pixel phones.
- Signal reliability generally proved good to decent across three major interstate carriers.
- Network architecture, including non-standalone 5G, emerged as a factor in deployment.
5G made a number of promises when it debuted. The first was the ability to handle excessive capacity. I tested that promise outside a baseball playoff game this past October, and I found it to be partially true. The other promise was better coverage coast to coast. Now, it was time to head out and give that a try. How 5G could improve coverage outside of city centers.
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To do this, I took those same Google Pixel 10 Pros on a road trip across the most boring highway in America (and, thankfully, a different highway home) through the bulk of central Indiana and Illinois. I also passed through parts of Kentucky and Tennessee. Since I live in Chicago, I have found 5G coverage to be pretty great, but what about when I leave the big city?
That’s what I wanted to find out. While you were probably shopping for some of the best Black Friday deals you could find, we were driving for 13 hours from Chicago to Nashville.
How I tested
This time around, I wanted to test not only network speed but overall coverage. So, I took those same three Google Pixel 10 Pros — one each with an AT&T, Verizon, and T-Mobile eSIM card and I attached them to a 2×4 pine board. I plugged them into an Anker Solix C1000 Gen 2 portable power station.
Then I loaded up nPerf, which is an app that measures connectivity. There is actually a ton of functionality built into this app, but for my purposes, I wanted an app that would measure signal strength and connectivity as I drove through the heartland of the Midwest. nPerf measures the location, carrier, signal strength, and a ton of other useful information for network professionals around 1,500 times per minute.
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The company graciously provided me with a spreadsheet of all those stats. By the time I got back home, I had over 120,000 data points to examine. Needless to say, it was pretty comprehensive.
Also, every hour or so, we would pull over at the nearest exit to run speed tests. For this, I used an iPhone 17 loaded with three eSIMs, one each from the same three carriers. At the stop, I mounted the iPhone on a tripod, ensuring the same positioning for each carrier. I cycled through all three carriers, running speed tests for each and recording the results. All in all, I had a lot of data to work with. Some of the results were surprising, some were not.
The results
As you can see, speeds were generally excellent for the most part. Out of 18 locations, each carrier reached the single digits only twice. They largely hung around in the double and triple-digit areas, which is to be expected in this day and age. But there’s one additional factor to consider.
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As we drove, when we hit the one-hour mark, we looked for a place to pull off, such as a rest stop or a gas station. That’s fine, but it’s also where a lot of people stop for various reasons. If I were building network coverage, I would focus on areas like that to build up first. It’s where the people will be. That’s why I wanted to test the signal all the way down and all the way back, and that’s where nPerf steps in.
Let’s not forget that carriers have been building 5G networks for over six years now. What does network coverage look like in between those hotspots?
Standalone 5G vs. Non-standalone
One of the things that surprised me was that of the three carriers, only T-Mobile managed any connectivity with a non-standalone (NSA) configuration. Non-standalone 5G deployments rely on existing 4G architecture to help with some of the basic nuts and bolts of establishing and maintaining a 5G connection. A standalone 5G connection, on the other hand, utilizes 5G infrastructure from the ground up.
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NSA networks are faster and cheaper to set up because they utilize existing infrastructure; however, SA 5G is considered the long-term solution. The key difference comes in latency. Since NSA networks utilize 4G to establish and maintain connections, latency can be affected. The time this makes the biggest difference is in gaming or in remote control applications.
In those cases, latency needs to be as low as possible. In regular day-to-day kinds of activities, you won’t really notice much of a difference. Still, that metric can give you an idea of what phase of the 5G rollout the various carriers are in. So here are the results:
This chart breaks down the 120,000 data points into three key areas: type of network connection (5G/LTE/etc), basic level of connection (how many bars your phone displayed), and network connection strength (in dBm — higher is better).
Overall, T-Mobile appears to have the most extensive 5G coverage, both in Non-Standalone and Standalone modes, with a coverage rate of 96.2 percent. That’s remarkable, considering our car covered over 1,000 miles on this trip. All three carriers had decent or good signal strength for over 80% of the trip, which is also really good. AT&T’s and Verizon’s 5G coverage both clocked in at over 35%, which is good, but not particularly impressive.
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All three carriers had decent or better signal strength for over 90% of the trip. That’s also very good considering what I was expecting. The most eye-popping metrics coming from this trip include Verizon’s speed in Louisville, Ky, at just under 4GBps down.
As a side note, it seems like Verizon always has at least one eye-popping result like that, so good for them. Another particularly interesting stat is T-Mobile’s 5G deployment. With numbers like that, it’s easy to believe that T-Mobile might have what it calls the “best nationwide 5G network”.
My verdict
All the same, it’s essential to remember that I conducted these tests while driving on Interstates, which are typically congestion-heavy zones. It’s worth repeating, if I were going to build a network, I would probably start with Interstates. If you road trip along country roads (which may be the subject of an article in the future), then the story might be very different.
However, I set out to test 5G networks on a road trip, which typically involves traveling along interstates and stopping at gas stations along the way. Overall, it’s reassuring to see that all three networks are building appropriately, and regardless of where you find yourself stuck on the side of the road, there’s a good chance you’ll have a strong enough signal to call for help.
