What two connection methods are used for most geofencing applications?

Global Positioning System (GPS) data and data about local Wi-Fi networks are the two most commonly used protocols to help geofencing applications determine where they are. When a known Wi-Fi signal is gained or lost, the geofencing application knows it is within range of that network. GPS data is even more useful because it can work in most locations and provide accurate location data. Although Bluetooth is sometimes used for geofencing, its limited range means that it is a third choice. Cellular information would require accurate tower-based triangulation, which means it is not typically used for geofencing applications, and of course USB is a wired protocol.