A land based method and apparatus for providing precise time and position (terrestrial alternative of the global positioning system - gps)

摘要

A system and method for providing precise TIME and TIME OF DAY information from the GPS network to mobile receiving units in an efficient and cost effective manner which includes the capability of including reliable real-time position data in cell phones that will meet the FCC requirement of electronic location of 911 calls from cell phones (E9-1-1). The invention operates over a dedicated radio frequency band using two radio channels. Base and Slave Models are used which time share the common radio spectrum. Transmitters are programmed to transmit only in their assigned time slot so as to prevent radio signal interference in any given geographic area.