Patent ID: 7143130

Claim:
A multi-tracking method, comprising the steps of (a) providing a plurality of portable multi-tracking units, wherein one of said portable multi-tracking units acts as a host unit while the other portable multi-tracking units act as client units; (b) providing host position data of said host unit by a positioning unit of said host unit, wherein said host position data contains GPS signal and IMU position information allowing to compensate said GPS signal in areas where GPS signal is not available; (c) receiving client position data and client identifications of said client units through a public wireless internet, so as to provide said host unit with client locations of said client units; and (d) sending said host position data and a host identification of said host unit to a wireless internet server provider via said public wireless internet, so as to provide said other client units with a host location of said host unit, wherein each of said portable multi-tracking units is capable of having locations of the other portable multi-tracking units.