In the live view of Plume motion, you can get a rapidly updating idea of how much movement the kit sees. You’re looking at my kids wandering around the living room right now.
Plume Motion has a log area where you can see history of motion in the house. See that blip at 2AM? That’s when the movie I was watching finished, and I got up and went to bed.
There’s a “last seven days” version of the Plume motion log as well. There’s still enough granularity here to figure out what time of day motion tends to occur.
At CES , Wi-Fi mesh kit manufacturer Plume announced the addition of motion-sensing capability to its newer Superpod devices. Before we go any further, let’s be clear about what we’re talking about — this is not
detection of a device you ‘re holding, like a phone or tablet. Instead, Plume is doing real-time analysis of extremely low-level RF data pulled from the Superpods’ radios. This is real motion detection, with no gimmicks involved. (Plume Motion requires Superpods — at least for now. The Superpods can also use stationary devices — including any original generation pods, or computers or IoT devices connected to the Wi-Fi — to further refine their detection.
Plume co-founder Adam Hotchkiss explained to us that, although any Wi-Fi device could theoretically be used to sense the data necessary to analyze motion, not all Wi-Fi chipsets actually expose that data. The Qualcomm IPQ
chipset used in the Superpods exposes the necessary RF data, but the older QCA
Hotchkiss told us that most (if not all) Wi-Fi 6 chipsets provide sufficient low-level RF data access for Plume Motion, so we may start seeing similar features from competing vendors in the next year or two.
How it works
Although the idea of sensing motion using Wi-Fi seems novel, the underlying physics is well established. Both 2.4GHz and 5GHz spectra have high absorption factors for water, so human (or animal) bodies present measurable interference to signals on those frequencies. Devices which have multiple antennas can therefore spot changes in the RF noise floor with some directionality and, with sufficient analysis, can isolate patterns corresponding to movement.
Professional security devices have been using 2.4GHz RF to sense motion for quite some time. I found that out the hard way a year or so ago. A small business had trouble getting reliable service in the rear of its building and did not want to invest in multiple access points — so I moved its router up above head height.
Moving the router solved the business’ Wi-Fi problems, but it caused a new one — the security alarm started going off for no apparent reason. After much head-scratching, I discovered that a Bosch intrusion
sensor was just on the other side of an interior wall, at the same height — and it also operated on 2.4GHz.
When a device at the back of the office requested data, the return transmission from the router — a Netgear Nighthawk — would Swamp the sensor, which would report motion detected. So the concept of motion detection with Wi-Fi frequencies isn’t novel at all — just the idea of using your actual Wi-Fi gear to do it, rather than separate, dedicated devices.
Testing Plume Motion
In this clip, I open the Plume app on my phone, toggle into the motion detection, then put the phone down and walk around the house.