How Wi-Fi motion sensing works is, at its core, a story about a Wi-Fi radio measuring tiny changes in the way its own signals travel through a home or business. When a person walks across the room, the radio waves bouncing around the space change in small but precise ways: some energy is absorbed by...

The security camera on the front door has become dramatically smarter over the past few years. AI detection. Facial recognition. Smart deterrence that can warn a stranger off the porch through a speaker. The cameras have deserved the attention they have been getting. The alarm sensors inside the house, though, the motion detectors in the...