POSITIONING SYSTEMS UTILIZING MOBILE TELEPHONE SYSTEM FOR CORRECTION SIGNALS

摘要

A positioning system where receiving stations such as multipurpose mobile communications devices (25) can thereby calculate their position; the system further including base stations (28) adapted to receive position information from the receiving stations (25) over a communications path (22) of a mobile telephone system. The system allows the receiving stations to receive a correction signal (13) from a correction station (14) over the communications path (22) on a special signalling layer (24) whereby the receiving stations can calculate a corrected position. The system can be used in conjunction with many forms of mobile telephone system.