Satellite system and method of deploying same

• US 6,460,808 B2
• Filed: 10/23/2001
• Issued: 10/08/2002
• Est. Priority Date: 11/09/1998
• Status: Expired due to Term

• Current Assignee: Hughes Electronics Corporation (AT&T, Inc.)
• Original Assignee: Hughes Electronics Corporation (AT&T, Inc.)
• Inventors: Chang, Donald C. D., Wang, Arthur W., Yung, Kar W., Mayfield, William W., Cheng, David C., Novak, John III, Taormina, Frank
• Primary Examiner(s): Poon, Peter M.
• Assistant Examiner(s): JAKEL, KEVIN W
• Application Number:
  US10/008,675
• Publication Number:
  US 20020053627A1
• Time in Patent Office: 350 Days
• Field of Search: 244/158.R, 244/63
• US Class Current: 244/158.4
• CPC Class Codes: H04B 7/195 Non-synchronous stations

Abstract

A satellite communication system has a first deployment of a plurality of satellites deployed in a medium earth orbit and two later deployments of a plurality of satellites deployed in the medium earth orbit. The first deployment is spaced so that the second deployment may be easily deployed and interleaved into the first deployment. A ground terminal is used for communicating with the satellites in the first and second deployments.

Claims

1. A communications system for fixed users, comprising:

a first deployment of a plurality of position-adjustable satellites deployed in a medium earth orbit;

the first deployment of satellites having a first configuration corresponding to an initial operation configuration having orbital voids;

a second deployment of a plurality of position-adjustable satellites deployed in the medium earth orbit in said orbital voids, and

a ground terminal having a fixed one-dimensional antenna.

2. A communications system as recited in claim 1 wherein said medium earth orbit is substantially about 15,000 km above the earth.

3. A communications system for mobile communications, comprising:

a first deployment of a plurality of position-adjustable satellites deployed in a medium earth orbit;

the first deployment of satellites having a first configuration corresponding to an initial operation configuration having orbital voids;

a second deployment of a plurality of position-adjustable satellites deployed in the medium earth orbit in said orbital voids, and

a ground terminal having a two-dimensional tracking antenna.

4. A communications system as recited in claim 3, wherein said antenna is electronically directed.

5. A communications system as recited in claim 3, wherein said medium earth orbit is at an altitude above the earth selected to increase the elevation angles in the most populated latitudes of the earth.

6. A medium earth orbit satellite communications system, comprising:

a plurality of medium earth satellites deployed on the equatorial plane at an altitude such that the path of the plurality of medium earth satellites is substantially not in the line of sight of geostationary satellites.

7. A medium earth orbit satellite communications system as recited in claim 6 wherein said plurality of medium earth satellites are in the line of sight of geostationary satellites only in a narrow region around the equator.

8. A method of increasing the size of a satellite constellation in response to demand, comprising:

initially deploying, in a medium earth orbit, a minimum number of satellites necessary to achieve desired coverage, and

in response to increased demand, subsequently deploying, in the medium earth orbit, in at least one subsequent deployment, additional satellites, such that said additional satellites are interleaved with said minimum number of position-adjustable satellites.

9. A method of increasing the size of a satellite constellation as recited in claim 8, wherein said step of initially deploying comprises the step of deploying said minimum number of satellites in a single launch.

10. A method of increasing the size of a satellite constellation as recited in claim 8, wherein the minimum number of satellites equals four.

11. A method of increasing the size of a satellite constellation as recited in claim 8, wherein the additional satellites deployed in each one of said at least one subsequent deployment are deployed in a single launch.

12. A method of increasing the size of a satellite constellation as recited in claim 8, further comprising adjusting the position of at least one satellite from the group consisting of said minimum number of satellites and additional satellites of said at least one subsequent deployment by east/west station keeping.