Paging/messaging system using GPS satellites

• US 5,625,363 A
• Filed: 03/15/1995
• Issued: 04/29/1997
• Est. Priority Date: 03/15/1995
• Status: Expired due to Term

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Stanford Telecommunications, Inc. (Nokia Corporation)
• Inventors: Spilker, James J.
• Primary Examiner(s): Issing, Gregory C.
• Application Number:
  US08/413,986
• Time in Patent Office: 776 Days
• Field of Search: 342/357, 342/353, 342/352, 455/12.1, 455/13.1
• US Class Current: 342/352
• CPC Class Codes: G01S 19/02 Details of the space or ground control segments
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: H04B 7/18576 Satellite systems for providing narrowband data service to fixed or mobile stations, e.g. using a minisatellite, a microsatellite for selecting H04W

Abstract

A paging/messaging system using the L3 transmission channel of a constellation of GPS satellites orbiting the earth, is comprised of an earth-based injection terminal having a source of paging/messaging signals and a radio transmitter for broadcasting paging/messaging on the L3 transmission channel to in-view ones of the constellation of GPS satellites. A plurality of earth-based mobile receiving stations, each mobile receiving station having an omnidirectional receiving antenna and an L3 transmission channel receiver for receiving the L3 transmission channel broadcasts from the in-view ones of the constellation of GPS satellites and demodulating and decoding to recover the paging/messaging signals, a display as used to present the paging/messaging signals to a designated user the recovered paging/messaging signals. At least one of said earth-based mobile receiving stations includes GPS position receiver for receiving GPS signals from the in-view satellites and determining the position of the mobile receiving station, and presenting the position information to the user on the display.

Claims

1. A paging/messaging system using the L3 transmission channel of a constellation of GPS satellites orbiting the earth, comprising:

an earth-based injection terminal having a source of paging/messaging signals and a UHF radio transmitter having an anti-jam uplink channel for broadcasting said paging/messaging signals on an anti-jam uplink transmission channel to in-view ones of said constellation of GPS satellites, and

a plurality of earth-based mobile receiving stations, each mobile receiving station having an omnidirectional receiving antenna and an L3 transmission channel receiver for receiving the L3 transmission channel broadcasts from said in-view ones of said constellation of GPS satellites and demodulating and decoding to recover the paging/messaging signals and means to present the paging/message signals to a designated user.

2. The paging/messaging system defined in claim 1 wherein at least one of said earth-based mobile receiving stations includes GPS position receiver means for receiving GPS signals from said in-view satellite and determining the position of said mobile receiving station.

3. A paging/messaging system using the L3 transmission channel of a constellation of GPS satellites orbiting the earth, comprising:

an earth-based injection terminal having a source of paging/messaging signals and a frequency hopped UHF radio transmitter, said UHF radio transmitter having an anti-jam uplink channel for broadcasting said paging/messaging to in-view ones of said constellation of GPS satellites, and

a plurality of earth-based mobile receiving stations, each mobile receiving station having an omnidirectional receiving antenna and an L3 transmission channel receiver for receiving the L3 transmission channel broadcasts from said in-view ones of said constellation of GPS satellites and demodulating and decoding to recover the paging/messaging signals and means to present the recovered paging/message signals to a designated user.

4. The paging/messaging system defined in claim 3 wherein at least one of said earth-based mobile receiving stations includes GPS position receiver means for receiving GPS signals from said in-view satellite and determining the position of said mobile receiving station, and presenting said position to said user.