초록 ▼

A GPS system has a plurality of satellites transmitting time and location data over radio frequency signals which enable a mobile GPS receiver on the ground to determine its position, includes a source of satellite data message block containing the ephemeris and time modes of the GPS satellites whic

A GPS system has a plurality of satellites transmitting time and location data over radio frequency signals which enable a mobile GPS receiver on the ground to determine its position, includes a source of satellite data message block containing the ephemeris and time modes of the GPS satellites which is independent of the satellites, and an independent cellular telephone channel having a voice channel, a data-in-voice modem including a notch filtering circuit in the voice channel (transmits and receive) and circuits for inserting and retrieving data in and from the notch for accessing said satellite data message block and controller means connecting said satellite message data block to said mobile GPS receiver.

대표청구항 ▼

[ What is claimed is:] [6.] A modem for use in a subscriber telephone in a cellular telephone system having one or more cell sites servicing a plurality of subscriber telephones with data utilization devices, said modem comprising transmit and receive channels, said receive channel comprising a firs

[ What is claimed is:] [6.] A modem for use in a subscriber telephone in a cellular telephone system having one or more cell sites servicing a plurality of subscriber telephones with data utilization devices, said modem comprising transmit and receive channels, said receive channel comprising a first filter delay line to receive voice and data signals, a first bandstop filter for transmitting a voice input to said subscriber telephones and data signals to said data utilization devices, respectively; said transmit channel having a second filter delay line connected to receive voice signals from said cellular telephone, a second bandstop filter connected to said filter delay line for providing a frequency notch in said voice signals from said cellular phones; an interface for receiving; of binary data from a source of G.P.S. data; and means for converting to binary data from said source of binary data to tone signals and for transmitting said tone signals within said frequency notch and; control means for converting for selectively controlling said first and second bandstop filters to allow data to be transmitted and received in said transmit and receive channels, respectively.