[Christien]

Any GPS tracker would require some kind of ongoing monitoring plan. The GPS unit itself simply sends and receives signals to the satellites, nothing else. It requires some form of communication method to relay its position to you, and that's usually (always?) done through the cellular network with what's basically text messages. When you ping the unit to get its location, you're basically texting it a request, then it texts you back with the coordinates. I don't know of any other way of communicating with them.