At Ars, we get daily product pitches that range on a scale from “must review” through “no thanks” to “WTF.” So when a representative for a small company’s PR firm reached out with a pitch for a “radio signal that’s thousands of times more robust than Bluetooth or Wi-Fi” and invited us to “take the Wi-Fi challenge,” it pegged my BS meter—but I took a closer look anyway.

It turns out that Sure-Fi isn’t intended to replace Wi-Fi at all. When Ars spoke to Sure-Fi president Mark Hall, he clarified that the company’s gear is high tech RF for industrial controls, and it’s not intended for a consumer audience. It uses 900MHz spectrum RF chirp communications to establish a low-bandwidth, high-reliability connection between industrial equipment (such as HVAC systems or electronic security gates) and their controllers.

With a typical throughput of around 300 bits per second, you definitely wouldn’t want to browse the Internet across a Sure-Fi bridge. That’s roughly equivalent to the external dial-up modem I used to connect to BBSes in the mid-1980s—and it would take more than an hour to load Ars Technica’s current front page. But you can get a lot done in 300 bits per second if you don’t need graphics. For industrial controllers that really only need to relay simple commands and occasional meter readings, it’s more than enough. It would also make one heck of an RC drone controller!

Recently, I took the company’s technology for a spin with a pair of hand-held demo communicators about the size of a kid’s walkie-talkie. They don’t do much—just light up with a signal strength reading on both devices, whenever a transmit button on either is pressed—but that’s enough to get a good indication of whether the tech will work to solve a given problem. The signal strength reads from zero to six bars; as long as you consistently get a single bar, the company says that’s good enough for a reliable connection.

Testing

The first place I tested Sure-Fi’s demo gear was my own suburban home. First, I stuck one of the demo units in the microwave. A consumer microwave is a far cry from a Faraday cage, but it’s generally good for eliminating 80% or more of any RF signals under 6GHz. The little demo units weren’t impressed, and they connected at their full 6-bar rate. Then I took a unit downstairs to my office and tried again—still with a full six-bar rating. My house is built into a hill, and my home office is a subterranean lair—its floor is two feet below ground level in my back yard, and it’s closer to 15 feet below ground level at the front yard. At this point, I wasn’t sure whether to be impressed or suspicious, so I raised the stakes.

First, I rigged up a MacGuyver-esque sling from a sunglasses bag and the studio mic I use to record podcasts. That got the demo unit in my office in view of my webcam so I could check it remotely and make sure that both units lit up the same amount, at the same time, as I drove around my suburban neighborhood. I discovered I could connect anywhere in about a half mile radius, despite one unit being in my underground office and the other in my closed, moving car. I couldn’t find any hint of shenanigans, either. The office unit always lit up at the same strength as the one I had in the car with me. Outside of that rough half-mile, I couldn’t get a connection.

At this point, I was thoroughly impressed—but I wanted to see how the RF chirp handled higher distances without one end being underground. So I took both units out to my parents’ house in a thoroughly rural area to see how far the signal could punch through heavily forested terrain, again, without one end being underground.

With one unit sitting on a coffee table in the living room and the other in my car, I drove a patrol over the dirt and paved roads around the house. The units connected reliably at one to three bars along most of the route at up to a mile away, with only a few exceptions at valley bottoms. None of the tests shown were stationary or taken from outside the car—I was just pressing the connect button like a fiend while driving at an average of 35mph.

At this point it occurred to me that there was one more test I should really make. I once had a six-month-long running war with a vendor who mistakenly believed that their HVAC system couldn’t communicate across the LAN to its controller because of “the IT guy’s firewall.” (The actual problem was that they’d run their own Ethernet cable and miswired it horribly.) This would make a great test for Sure-Fi’s demo hardware, both because it would have solved a real problem for a real HVAC vendor and because it was an absolutely horrible place for point-to-point RF communication.

The HVAC system and controller were each in a basement, but they were underneath separate buildings with no passageway between them. Google Maps gave me about 104 feet distance between the unit and controller, at about 10 feet below ground and 15 feet below ground respectively. At this point, I wasn’t even surprised when the demo unit lit up—it varied between one and two bars of signal, but it never failed to connect.

Conclusion

It’s very nerdy-cool to see these things communicate underground, through trees and buildings, and up to a mile away. But unless you happen to be an HVAC or security system vendor, these particular RF chirp devices probably aren’t going to be of any direct use to you. The underlying, nearly unjammable long-range technology could, however, lend itself to a lot of consumer-focused applications in the future—and the tech would do it without screwing up your Wi-Fi along the way. After a few makeshift at-home tests, we certainly hope to also see this kind of tech in drone controllers, security system sensors, and similar low-bandwidth applications in the near future.

https://arstechnica.com/?p=1569681