Caterpillar's Product Link system places two antennas on the asset being tracked—one for receiving information from the GPS satellite system, and the other for receiving and transmitting signals via a low-Earth-orbiting (LEO) satellite system. Messages from a machine in the field, for example, are transmitted to the LEO satellite system, then via a ground station to a message control center. The machine owner can access these messages via the Internet. The system provides four location reports and one service-meter reading daily. Additional reports include Product Watch alarms, diagnostic reporting and fuel consumption.