What is Wi-Fi Sensing?
A practical guide to how ambient Wi-Fi signals can detect motion, presence, and falls - without cameras and without wearables.
Reading time: 6 min · For care professionals, IT teams, and innovation leads
The short answer
Wi-Fi Sensing is a technique that uses the radio signals already present in a room - the same ones that carry your internet - to perceive how the environment is changing. When a person moves, their body subtly disturbs those signals. By measuring those disturbances (a property called Channel State Information, or CSI) and analysing them with AI, a device can understand presence, motion, posture, and even fall-risk events. No cameras. No microphones. Nothing to wear.
From radio waves to insight
Standard Wi-Fi access points and a discreet sensor continuously exchange radio signals across the room.
Each signal carries fine-grained data about how it travelled through space — reflections, absorption, multipath.
On-device models analyse CSI patterns locally to recognise motion, posture, and events in real time.
Output is structured events — presence, activity, fall-risk — sent to care teams, never raw signals.
Why care teams choose Wi-Fi Sensing
Eldercare environments have specific constraints: residents value dignity and privacy, staff are stretched, and IT infrastructure has to stay simple. Wi-Fi Sensing fits those constraints in a way that cameras, wearables, and PIR sensors usually do not.
No images, no audio, no identification. There is nothing to leak because nothing is recorded.
Perceives activity across one or multiple rooms — even through walls — without ever pointing a lens at anyone.
No wearable to charge, no button to press, no adoption curve. The room itself becomes the sensor.
Wi-Fi Sensing vs. cameras, PIR, and wearables
| Approach | Privacy | Coverage | Burden on resident |
|---|---|---|---|
| Cameras | Identifiable imagery | Line of sight | Passive but intrusive |
| PIR sensors | Private | Coarse, line of sight | None |
| Wearables | Depends on device | Only when worn | Charging, adoption |
| Wi-Fi Sensing | No images, no audio | Whole room, through walls | None |
Use cases in eldercare
- Fall detection and response. Detect fall-risk events, alert the right caregiver in real time, and track the response — the focus of ZoeFall.
- Daily habits monitoring. Build a baseline of presence, movement, and rest patterns to spot meaningful changes early.
- Night-time safety. Understand sleep and wandering without a camera in the bedroom.
- Operational signals. Give care teams clear, structured indications rather than raw sensor noise.
Frequently asked questions
Yes. The system measures changes in ambient radio signals, not images or audio. It cannot identify individuals and there is no camera feed to leak.
No. Residents do not wear, charge, or carry anything. A discreet plug-in device uses the existing Wi-Fi environment to perceive motion in the room.
Cameras record identifiable imagery; PIR sensors only detect coarse presence in line of sight. Wi-Fi Sensing perceives motion through walls and across a room without recording images.
Yes. By analysing CSI patterns with Edge AI, the system can distinguish fall-risk events from normal activity and alert care teams in real time.
See Wi-Fi Sensing applied to fall detection
ZoeFall combines Wi-Fi Sensing, Edge AI, and Human Activity Recognition to detect fall-risk events and track the care response — without cameras or wearables.