5G signals that rely on so-called ‘millimeter wave’ technology don’t propagate well through walls, windows, people, or water, including water vapor in the atmosphere. This has been known since before 5G launched. It’s a limiting factor for where the technology can be deployed. But now, new reports show that 5G has an even more implacable foe: summer.
According to reports from both The Wall Street Journal and PCMag, the current bare handful of 5G devices available to consumers literally wilt and die if you attempt to use them in hot weather. PCMag’s Sascha Segan writes:
On a hot Las Vegas morning, my two Galaxy S10 5G phones kept overheating and dropping to 4G. This behavior is happening with all of the millimeter-wave, first-generation, Qualcomm X50-based phones when temperatures hit or exceed 85 degrees. We saw it with T-Mobile in New York, with Verizon in Providence, and now with AT&T in Las Vegas. It’s happened on Samsung and LG phones, with Samsung, Ericsson, and Nokia network hardware.
The WSJ is even more stark. Joanna Stern writes:
The Samsung Galaxy S10 5G isn’t reliable in the summer—unless, well, you summer in Iceland.
When I ran tests, the phone’s 5G often switched off due to overheating, leaving me with a 4G connection. Cellular carriers demo-ing or testing the phone have taken to cooling the devices with ice packs and air conditioners.
Here, for reference, is a map of US temperatures today.
The situation is awe-inspiring. We already knew that millimeter-wave 5G came with a laundry list of conditions and must-haves to ensure good performance, but I admit, it never occurred to me that the companies that drew up and developed the standard would deploy it in products that can’t deal with the reality of sunlight. Admittedly, that’s because I thought deploying a network technology that degrades when there’s a lot of water vapor in the air was a bad enough idea that obviously there couldn’t be anything worse waiting in the wings, right?
Right?
Wrong.
PCMag goes on to say: “AT&T being AT&T, the company leaves the ‘5G+’ indicator on the phone even when it’s dropped to 4G from overheating.”
This is both the most enraging and the least surprising thing ever.
Samsung’s response to this problem, according to the WSJ? “As 5G technology and the ecosystem evolve, it’s only going to get better.”
Yeah. So let’s talk about that. First of all, one device that probably isn’t going to “get better” is the Samsung Galaxy 10 5G. Later products with different modems could be better, but the hardware in a first-generation phone is going to be what it’s going to be, and the chances of a firmware update that miraculously improves things is limited. If AT&T, Verizon, Samsung, LG, and the other companies making these products had such an update in their back pocket, it’d be splashed as news all over these stories in the first place. The message would be something like: “Current 5G devices overheat easily, but carriers and manufacturers promise that fixes are coming.”
There has been no such messaging.
Stern appears to have tested her 5G speeds by downloading files from Netflix, which is a pretty reasonable way to do it. Her download time on 5G for an episode of Stranger Things S3 was listed ~34 seconds. Keep that in mind as you read this:
In Atlanta, where it was 90 degrees the day I visited, I could run only one or two 5G download tests before the phone would overheat and switch to 4G. When that happened, I’d head back to the car and hold the phone to the air vent. In Chicago, another day in the 90s, I had to wait until the sun went down to finish my Netflix download tests. In New York on an 83-degree day, I went with the ice-cooler trick: A minute or two in the cooler, and 5G switches back on.
The Samsung Galaxy S10 5G, a $1,300 device, is capable of running a max-speed connection for less than a minute (somewhere between 33 and 66 seconds) when temperatures break 85F.
One expects spotty connections and lower overall performance from first-generation networks and products. One does not expect the product to catastrophically fail when encountering the reality of outside ambient temperature., particularly when the only way to get good 5G performance is to stand so close to the antenna people think you’re dating.
Will This Improve?
To an extent, yes. There’s probably additional tuning that can be done to improve modem power consumption, but Qualcomm has told us for years that die shrinks provide only limited power consumption improvement for modems. Samsung, Apple, and other companies can perform advanced thermal analysis to see exactly where hot spots pop up and devise strategies to mitigate them, ranging from better internal cooling solutions to thicker chassis or better thermal interface materials. It’s unlikely we’ve reached the point where people start sticking fans in smartphones on the regular, but even a very small fan would likely fix this problem (at the cost of thickness, a bit of noise, and a little power).
In the past, we’ve seen discussions of using wax to quickly move heat in an enclosed area. Clearly, a bunch of designers have had ideas before about how one might deal with this issue. Beam-forming and other carrier technologies could also wind up reducing the amount of power that 5G signals require, thereby reducing device power draw.
But make no mistake. 5G signaling is going to require more power, and in today’s downright anorexic devices, that’s obviously already creating thermal problems. At the very least, this is one more limit on a 5G rollout that didn’t need more limits.
We’ve said before that 5G is very early and that people probably shouldn’t buy into it, but this issue seals the deal for me. I would never recommend that anyone buy a product whose premiere feature is likely to be unavailable when outside in the summer. Right now, if you buy a currently available 5G phone, you’re buying a device whose top speed may only be available from October through May depending on where you live.
