Sensing the whole home without a box in every room
PIR motion sensors miss you when you sit still; radar pucks are precise but need one in every room. Sensing from your existing Wi-Fi covers the whole home with no box to mount.
Sensing the whole home without a box in every room
If you want a home that knows where people are, you have three honest options today: the old motion sensor, the new radar puck, and sensing from the Wi-Fi that is already there. They are not equal, and the differences are mostly about coverage and what you have to install.
Motion, radar, and their limits
A PIR motion sensor — the white box in the corner — is cheap and everywhere, but it only sees movement. Sit still to read, and it decides the room is empty and kills the lights. It detects motion, not presence, and that gap is the source of most smart-home frustration.
mmWave radar sensors, like the well-regarded Aqara FP2, fixed that. A 60 GHz radar picks up the micro-movements of someone sitting or lying still, so it reports true presence, room by room, with real precision. The catch is geometry and install: a single unit covers roughly 40 m², it needs wiring and mounting, and whole-home coverage means buying, placing, and powering one in every room you care about.
Why we sense from the Wi-Fi
Stillsense takes the third path. Instead of adding a sensor to each room, it reads the Channel State Information in the Wi-Fi signals already crossing the home, plus a small node or two, to sense presence and movement across the whole space — no device in every room, nothing to mount, computed on the edge.
We are honest about the trade-off: a dedicated radar puck aimed at one room can resolve that room in fine detail. What Wi-Fi sensing offers instead is reach — coverage of the entire home from infrastructure that is already installed, with no camera and no microphone anywhere in it. For a house, or a care service fitting out many homes, the install you don't have to do is often the deciding factor.
Different tools, different jobs. Ours is the one that scales to the whole home without filling it with boxes.
Coverage and capability descriptions of PIR and mmWave radar reflect published product specifications and reviews (e.g. Aqara FP2), not Stillsense-measured comparisons.