Simulcast satellite paging system with over lapping paging reception locales

• US 5,483,665 A
• Filed: 06/01/1994
• Issued: 01/09/1996
• Est. Priority Date: 11/13/1990
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Pagemart Inc. (Spok Holdings, Inc.)
• Inventors: Lorang, Malcolm M., Linquist, Roger D.
• Primary Examiner(s): Pham, Chi H.
• Application Number:
  US08/252,455
• Time in Patent Office: 587 Days
• Field of Search: 455/12.1, 455/13.1, 455/13.2, 455/33.4, 455/51.1, 455/51.2, 455/54.1, 455/56.1, 340/311.1, 340/825.44, 370/100.1, 370/104.1, 370/108, 375/107
• US Class Current: 455/13.1
• CPC Class Codes: H04B 7/18567 Arrangements for providing additional services to the basic mobile satellite telephony service
• CPC Class Codes: H04H 20/67 Common-wave systems, i.e. using separate transmitters operating on substantially the same frequency
• CPC Class Codes: H04W 84/022 One-way selective calling networks, e.g. wide area paging

Abstract

A paging system includes a satellite uplink (40) for assembling paging information and transmitting it to a satellite (26). The satellite (26) is then operable to transmit in a simulcast manner all the information to various regional paging systems (42). Each of the paging systems (42) includes a plurality of towers (10) each containing a satellite receiver (50), a satellite dish (48) associated therewith and a paging transmitter (52). Each of the satellite receivers (50) are operable to receive the information transmitted from the satellite (26) at substantially the same time such that there is no phase difference between any of the towers, regardless of location. Therefore, the transmitters (50) can transmit through antennas (12) information at the paging frequency with substantially no relative delays relative to each of the antennas (12). A backup link receiver (28) is provided for interfacing with a backup link transmitter (70). In the event of a failure of the receivers (50) or the satellite (26), the link transmitter (70) will transmit the paging information directly to select ones of the towers (10) over a separate frequency.

Claims

1. A paging system, comprising:

a satellite having a predetermined footprint for generating timing information and transmitting said timing information on a downlink channel;

a plurality of paging sites disposed in the footprint of said satellite;

a plurality of satellite receivers, one of said satellite receivers disposed at each of said paging sites for receiving at least the timing information from said satellite, said timing information received at each of said satellite receivers at substantially the same time;

a paging source for generating paging information and transmitting it to each of said paging sites;

a paging receiver disposed at each of said paging sites for receiving said paging information;

a paging transmitter disposed at each of said paging sites for transmitting said received paging information on a paging frequency in accordance with said received timing information 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.

2. A method for transmitting paging information from a paging information source to mobile paging receivers, comprising the steps of:

providing a satellite having a predetermined footprint;

transmitting at least timing information from the satellite on a downlink channel within the footprint of the satellite;

providing a plurality of paging sites within the footprint of the satellite;

receiving the transmitted timing information from the downlink at each of the paging sites, the timing information received at each of the paging sites at substantially the same time;

transmitting paging information from the paging information source to each of the paging sites;

receiving the paging information at each of the paging sites;

transmitting the paging information in accordance with the received timing information on a paging frequency from each of the paging sites within a predetermined locale proximate to each of the paging sites for reception by the mobile paging receiver when the paging receiver is within one of the predetermined locales associated with the paging sites; and

each of the predetermined locales for adjacent ones of substantially all of the paging sites having substantial overlap such that if transmission of the paging information on the paging frequency from any of the paging sites fails, transmission of the paging frequency at the adjacent ones of the paging sites will provide sufficient field strength to be received by the mobile paging receiver in substantially all locations within the predetermined locale associated with the failed one of the paging sites.