Geofencing

Geofencing creates an invisible boundary around a physical location — usually your home. When your phone crosses that boundary (entering or leaving), it triggers an automation. For lighting, the most common use is "turn on the porch light and hallway when I arrive home" and "turn everything off when the last person leaves."

The technology uses your phone's GPS, Wi-Fi, and cell tower triangulation to determine your location relative to the geofence boundary. Most smart home apps let you set the radius — smaller for accuracy (but more battery drain), larger for reliability (but triggers earlier).

Geofencing is one of those smart home features that feels like magic when it works well. You pull into the driveway and the house lights up before you reach the door. But it can be finicky — GPS drift can trigger false arrivals, multiple family members complicate "last person leaves" logic, and battery optimization on phones can delay the trigger. Most platforms have improved dramatically, but expect some tuning to get it reliable.