Your Wi-Fi router might be doing more than just providing internet access. New technology is allowing these everyday devices to detect movement inside your home without using cameras or microphones. While this might sound futuristic, it's already being tested and used in smart homes and healthcare settings.
The idea is simple: when you move around your house, even slightly — shifting in bed, walking through a room, or breathing — you cause small changes in the wireless signals sent out by your router. These disturbances can be picked up and analyzed to understand motion. This process doesn’t involve visuals or sound but relies on detecting changes in signal strength and pattern.
The concept isn’t new. Back in 2015, researchers at MIT built a system that could track motion through Wi-Fi. The technology was so promising it was once demonstrated to then President Barack Obama for its potential use in fall detection for elderly people. Today, companies are exploring practical ways to use it, for example, Comcast’s Xfinity Wi-Fi Motion helps detect movement in homes, while other firms are applying it in hospitals to monitor patients.
How does this work?
This technology functions in two main steps. First, the router collects signal data from its surroundings. Then, using machine learning, it identifies patterns in those signals. Any movement, such as a person standing up, walking past a doorway, or even breathing affects the Wi-Fi waves, which helps the system understand what’s happening in the space.
Because Wi-Fi can pass through walls and furniture, this method can detect movement even in rooms where there are no devices. Newer routers, which come with better hardware and multiple antennas, are especially suited for this. Organizations like IEEE are also developing standards to make it easier for different devices to share and use this kind of data smoothly.
Privacy concerns you should know about
Although this technology doesn’t use video or audio, it still brings up serious privacy concerns. Experts warn that in theory, someone outside your home could use signal data to figure out if anyone is inside or even track movement patterns. A recent 2025 study by Chinese researchers pointed out that Wi-Fi sensing could reveal private details such as where someone is in the house or how often they move.
For now, most companies offer these features as optional. For instance, Xfinity’s motion sensing must be manually enabled in the app, and users can adjust the settings to limit what is tracked. However, cybersecurity experts recommend being cautious. As one industry leader put it, this is a powerful technology but it’s important to set boundaries before it becomes too invasive.