Orbit uses Bluetooth radio waves to communicate with the Orbit app on your phone or tablet. The Orbit app "discovers" an Orbit using the Bluetooth signal and then uses the location services of the device to update the location information for that Orbit.
Your Orbit can be discovered by your Smartphone or tablet from up to 30m/100ft, which is the standard range for Bluetooth.
Your Orbit and your phone are connected to each other when the Orbit app is always running (foreground or background), location services are enabled on your device; and your Orbit and device are within range of each other. If any of these 3 things are not true, your Orbit app, and device are not communicating with each other.