Simulcast satellite paging system with provision for signal interruption

Claim 2

A paging system, comprising: a satellite having a predetermined footprint for received paging information from a paging information source and transmitting said paging information on a down link channel; a plurality of paging sites disposed in the footprint of said satellite; a satellite receiver disposed at each of said paging sites for receiving the paging information from said satellite, said paging information received at the one of said satellite receivers associated with each of said paging sites at substantially the same time; a paging transmitter disposed at each of said paging sites for receiving the paging information on the output of said satellite receiver and transmitting said received paging information on a paging frequency within a predetermined locale proximate to each of said paging sites for reception by a paging receiver within said paging locale; a detection circuit for detecting the integrity of the signal received by said satellite receiver; and a transmission inhibiting circuit for inhibiting transmission by said paging transmitter when said integrity detection circuit detects that the integrity of the signal received by said satellite receiver is below a predetermined integrity threshold.

Claim 3

A paging system, comprising: a satellite having a predetermined footprint for received paging information from a paging information source and transmitting said paging information on a down link channel; a plurality of paging sites disposed in the footprint of said satellite; a satellite receiver disposed at each of said paging sites for receiving the paging information from said satellite, said paging information received at the one of said satellite receivers associated with each of said paging sites at substantially the same time; a paging transmitter disposed at each of said paging sites for receiving the paging information on the output of said satellite receiver and transmitting said received paging information on a paging frequency within a predetermined locale proximate to each of said paging sites for reception by a paging receiver within said paging locale; and said predetermined locales for substantially all adjacent ones of said paging sites having substantial overlap such that if one of said paging transmitters fails in its associated predetermined locale, said paging transmitters at the adjacent ones of said paging sites will provide sufficient field strength to be received by a paging receiver in substantially all locations within the predetermined locale associated with the failed one of said paging transmitters.

Claim 4

A paging system, comprising: a satellite having a predetermined footprint for received paging information from a paging information source and transmitting said paging information on a down link channel; a plurality of paging sites disposed in the footprint of said satellite; a satellite receiver disposed at each of said paging sites for receiving the paging information from said satellite, said paging information received at the one of said satellite receivers associated with each of said paging sites at substantially the same time; a paging transmitter disposed at each of said paging sites for receiving the paging information on the output of said satellite receiver and transmitting said received paging information on a paging frequency within a predetermined locale proximate to each of said paging sites for reception by a paging receiver within said paging locale; and said predetermined locales for substantially all adjacent ones of said paging sites having substantial overlap such that if one of said paging transmitters fails in its associated predetermined locale, said paging transmitters at the adjacent ones of said paging sites will provide sufficient field strength to be received by a paging receiver in substantially all locations within the predetermined locale associated with the failed one of said paging transmitters.

Claim 5

A paging system, comprising: a satellite having a predetermined footprint for received paging information from a paging information source and transmitting said paging information on a down link channel; a plurality of paging sites disposed in the footprint of said satellite; a satellite receiver disposed at each of said paging sites for receiving the paging information from said satellite, said paging information received at the one of said satellite receivers associated with each of said paging sites at substantially the same time; a paging transmitter disposed at each of said paging sites for receiving the paging information on the output of said satellite receiver and transmitting said received paging information on a paging frequency within a predetermined locale proximate to each of said paging sites for reception by a paging receiver within said paging locale; a backup system for being disposed at a fixed location for receiving the paging information from the paging information source; a link transmitter for receiving paging information from the output of said backup system and transmitting it over a communication link to select ones of said paging sites; a link receiver disposed at each of said select paging sites for receiving the paging information from said link transmitter over said communication link; delay circuitry for adjusting the time delay of said received paging information received by said link receiver; and an arbiter circuit for selecting the output of said link receiver for input to said paging transmitter when the output of said satellite receiver falls below a predetermined threshold.

Claim 6

A paging system, comprising: a satellite having a predetermined footprint for received paging information from a paging information source and transmitting said paging information on a down link channel; a plurality of paging sites disposed in the footprint of said satellite; a satellite receiver disposed at each of said paging sites for receiving the paging information from said satellite, said paging information received at the one of said satellite receivers associated with each of said paging sites at substantially the same time; a paging transmitter disposed at each of said paging sites for receiving the paging information on the output of said satellite receiver and transmitting said received paging information on a paging frequency within a predetermined locale proximate to each of said paging sites for reception by a paging receiver within said paging locale; a backup system for being disposed at a fixed location for receiving the paging information from the paging information source; a link transmitter for receiving paging information from the output of said backup system and transmitting it over a communication link to select ones of said paging sites; a link receiver disposed at each of said select paging sites for receiving the paging information from said link transmitter over said communication link; delay circuitry for adjusting the time delay of said received paging information received by said link receiver; and an arbiter circuit for selecting the output of said link receiver for input to said paging transmitter when the output of said satellite receiver falls below a predetermined threshold.

Claim 7

The paging system of claim 3 wherein said arbiter circuit is operable to inhibit transmission by said paging transmitter if the output of both said satellite receiver and said link receiver fall below a predetermined threshold.

Claim 8

The paging system of claim 3 and further comprising: a comparator for comparing the output of said delay circuitry with the output of said associated satellite receiver to determine the difference in time therebetween; a synchronizer for controlling said delay circuitry to adjust the delay of the received paging information output by said link receiver to minimize the time difference between the output of said delay circuitry and the output of said associated satellite receiver to substantially zero; and said arbiter circuit operable to hold the delay of said delay circuitry at the value that existed previous to selecting the output of said link receiver in response to the output of said satellite receiver falling below said predetermined threshold.

Claim 15

The method of claim 8 wherein the step of selecting the backup paging information is operable to inhibit transmission of paging information on the paging frequency if it is determined that the paging information from the satellite is not received and the paging information from the communication link is not received.

Claim 16

The method of claim 8 and further comprising the steps of: comparing the paging information received from the satellite on the downlink and the delayed paging information received from the communication link and determining the difference in time therebetween; adjusting the delay between the paging information received from the satellite and the delayed backup paging information received from the link frequency to minimize the difference therebetween to substantially zero; and the step of selecting the backup information operable to prevent further adjustments in time delay thereof.

Claim 17

A paging system, comprising: a paging source for generating paging information for transmission to a paging receiver disposed at one of a plurality of paging sites; a satellite having a predetermined footprint that includes said paging sites, said satellite operable to receive said paging information from said paging source and transmit said received paging information on a downlink channel within said footprint; a satellite receiver disposed on each of said paging sites for receiving said paging information from said satellite on said downlink channel, said paging information received at each of said satellite receivers at substantially the same time; a backup paging system having: a backup transmitter for receiving paging information from said paging source, a communication link connecting said backup transmitter to select ones of said paging sites, and a backup receiver disposed at the select ones of said paging sites for receiving said paging information from said backup transmitter over said communication link; synchronizing circuitry for synchronizing said paging information received over said communication link by said backup receiver to said paging information received by said satellite receiver; an arbiter for detecting the integrity level of the signal received from said satellite and selecting the paging information received by said backup receiver when said the detected integrity level is less than a predetermined integrity threshold level; and a paging transmitter disposed at each of said paging sites for transmitting said received paging information on a paging frequency within a predetermined locale proximate to each of said paging sites for reception by a paging receiver within said paging locale.

Claim 18

A paging system, comprising: a paging source for generating paging information for transmission to a paging receiver disposed at one of a plurality of paging sites; a satellite having a predetermined footprint that includes said paging sites, said satellite operable to receive said paging information from said paging source and transmit said received paging information on a downlink channel within said footprint; a satellite receiver disposed on each of said paging sites for receiving said paging information from said satellite on said downlink channel, said paging information received at each of said satellite receivers at substantially the same time; a backup paging system having: a backup transmitter for receiving paging information from said paging source, a communication link connecting said backup transmitter to select ones of said paging sites, and a backup receiver disposed at the select ones of said paging sites for receiving said paging information from said backup transmitter over said communication link; synchronizing circuitry for synchronizing said paging information received over said communication link by said backup receiver to said paging information received by said satellite receiver; an arbiter for detecting the integrity level of the signal received from said satellite and selecting the paging information received by said backup receiver when said the detected integrity level is less than a predetermined integrity threshold level; and a paging transmitter disposed at each of said paging sites for transmitting said received paging information on a paging frequency within a predetermined locale proximate to each of said paging sites for reception by a paging receiver within said paging locale.