POSITION LOCATING SYSTEM

摘要

A position locating system comprises a radio receiving base station (22) and a plurality of portable radio transmitter/receiver devices (21) each having means (25) for determining an Instantaneous global position for said device and adapted to signal said position to the base station, each device also being adapted to monitor transmissions from other devices within the system and to relay said messages from one device to another, whereby a message from a device out of range of the base station can be relayed to the base station.