Network architectures for LEO/GEO satellite-based communications systems

• US 6,556,828 B1
• Filed: 08/31/1999
• Issued: 04/29/2003
• Est. Priority Date: 08/31/1999
• Status: Expired due to Fees

• Current Assignee: Loral Skynet Corporation (MHR Holdings LLC (New York))
• Original Assignee: Loral Spacecom Corp.
• Inventors: Carlin, James W., Schroeder, Robert E., Hedinger, Robert A.
• Primary Examiner(s): VUONG, QUOCHIEN B
• Application Number:
  US09/386,268
• Time in Patent Office: 1,337 Days
• Field of Search: 370/279, 370/342, 370/319, 370/442, 370/320, 370/315, 370/316, 370/441, 455/12.1, 455/90, 455/427, 455/550
• US Class Current: 455/427
• CPC Class Codes: H04B 7/19 Earth-synchronous stations
• CPC Class Codes: H04B 7/216 Code division or spread-spectrum multiple access [CDMA, SSMA]

Abstract

Communications network architectures integrate communications using a geosynchronous satellite communications system including a geosynchronous communications satellite operating in the fixed satellite service (FSS) band and a low earth orbit satellite communications system including a plurality of low earth orbit communications satellites. A low earth orbit gateway having a terminal is used to communicate with the low earth orbit communications satellites using multiple access communication channels, and is used to communicate with a public switch telephone network. A geosynchronous gateway having a terminal is used to communicate with the geosynchronous communications satellite by overlaying multiple access communication channels onto fixed channel assignments and transmitting the overlayed channel assignments. The terminal in the geosynchronous gateway is also used to communicate with the public switch telephone network. A fixed terminal having a handset is used to selectively communicate with the low earth orbit communications satellite using the multiple access communication channels, and with the geosynchronous communications satellite by extracting the multiple access communication channels from the fixed channel assignments.

Claims

1. A communications network architecture comprising:

geosynchronous satellite communications system including a geosynchronous communications satellite;

a low earth orbit satellite communications system including a plurality of low earth orbit communications satellites;

a low earth orbit gateway comprising a terminal for communicating with the low orbit communications satellites using multiple access communication channels, and for communicating with a public switch telephone network;

a geosynchronous gateway comprising a terminal or communicating with the geosynchronous communications satellite by overlaying multiple access communication channels onto fixed channel assignments and transmitting the overlayed channel assignments, and for communicating with the public switch telephone network; and

a fixed terminal having a handset for selectively communicating with the low earth orbit communications satellite using the multiple access communication channels, and with the geosynchronous communications satellite by extracting the multiple access communication channel from the fixed channel assignments.

2. The architecture recited in claim 1 further comprising:

a mobile terminal having a hand,or communicating with the low earth orbit communications satellites using the multiple access communication channels, and with cellular sites of a public land mobile network.

3. The architecture recited in claim 2 wherein the mobile terminal interface by way of cellular sites to the public switch telephone network.

4. The architecture recited in claim 1 wherein the multiple access communication channels comprise a plurality of L-band channels and a plurality of S-band channels.

5. The architecture recited in claim 1 wherein the L-band channels are used to communicate from the terminals to the low/earth orbit communications satellites, and the S-band channels are used to communicate from the low earth orbit communications satellites to the terminals.

6. The architecture recited in claim 1 wherein the terminal in the geosynchronous gateway comprises a plurality of transponders that process 16.5 MHz traffic channels comprising thirteen 1.23 MHz code division multiple access (CDMA) carriers.

7. The architecture recited in claim 1 wherein the L-band channels are located between 1610 and 1626.5 MHz, the S-band channels are located between 2483.5 and 2500 MHz, the fixed channel assignments used to communicate between the geosynchronous gateway and the geosynchronous communications satellite are located between 5091 and 5250 MHz, and the fixed channel assignments used to communicate between the geosynchronous communications satellite and the geosynchronous gateway are located between 6873 and 7055 MHz.

8. The architecture recited in claim 1 wherein the fixed terminals comprise a block converter for converting the fixed channel assignments transmitted by way of the geosynchronous communications satellite into multiple access communication channels processed by the terminals, and for converting multiple access communication channels output by the terminals into fixed channel assignments that are uplinked to the geosynchronous communications satellite for transmission to the geosynchronous gateway.

9. The architecture recited in claim 1 further comprising a very small aperture terminal coupled to a wired loop interconnecting a plurality of conventional telephones.

10. The architecture recited in claim 1 further comprising a very small aperture terminal for communicating with the geosynchronous communications satellite using the fixed channel assignments.

11. The architecture recited in claim 10 wherein the very small aperture terminal is coupled to a wireless loop interconnecting a plurality of conventional telephones.

12. The architecture recited in claim 10 wherein the very small aperture terminal is coupled to a public use handset.