Communication system having frequency reuse in non-blocking manner

• US 6,725,013 B1
• Filed: 06/15/2000
• Issued: 04/20/2004
• Est. Priority Date: 06/15/2000
• Status: Expired due to Term

• Current Assignee: DIRECTV, LLC (AT&T, Inc.)
• Original Assignee: Hughes Electronics Corporation (AT&T, Inc.)
• Inventors: Chang, Donald C. D., Rosen, Harold A., Lim, Wah L., Chang, Ming U., Feria, Ying, Wang, Weizheng
• Primary Examiner(s): Tran, Sinh
• Assistant Examiner(s): NGUYEN, DAVID Q
• Application Number:
  US09/594,375
• Time in Patent Office: 1,405 Days
• Field of Search: 455/447, 455/63, 455/431, 455/427, 455/13.1, 455/3.02, 455/12.1, 455/45, 455/98, 455/FOR.215, 455/3.2, 343/765, 343/766, 343/816, 342/354, 342/359, 342/368
• US Class Current: 455/13.1
• CPC Class Codes: H04B 7/18508 with satellite system used as relay, i.e. aeronautical mobile satellite service

Abstract

A communications system (10) and method of operating the communications system includes a high altitude communication device (12) that communicates with a plurality of user terminals and a gateway station (30). The gateway station (30) couples the users to terrestrial networks (32) and other users. The high altitude communication device (16) has a controller that generates a second beam having the first frequency to a service (26). The stratospheric platform (12) does not generate the second beam within a blocking area. User terminals within the service area outside the blocking area are configured to receive the first beam and the second beam.

Claims

1. A communication system for use with a geosynchronous satellite broadcasting a first beam at a first frequency comprising:

a first stratospheric platform having a substantially fixed separation angle with respect to the satellite, said first stratospheric platform generating a second beam having the first frequency to a service area, said stratospheric platform defining a geographically fixed blocking area as a function of the separation angle, said stratospheric platform not generating said second beam within the blocking area; and

user terminals outside the blocking area configured to receive the first beam and the second beam.

2. A system as recited in claim 1 wherein said user terminals comprise directional antennas.

3. A system as recited in claim 1 further comprising a second stratospheric platform generating a third beam having the first frequency.

4. A system as recited in claim 3 wherein said user terminals receive signals from and transmit signals to said first stratospheric platform and said second stratospheric platform.

5. A system as recited in claim 1 wherein the second beam is generated from a secondary payload.

6. A system as recited in claim 1 wherein the blocking area has the separation angle between a first position of said stratospheric platform and a second position of the satellite less than a predetermined angle.

7. A system as recited in claim 6 wherein said predetermined angle is about 4 degrees.

8. A system as recited in claim 6 wherein said predetermined angle is about 7 degrees.

9. A communication system for use with a system of geosynchronous satellites broadcasting a first beam at a first frequency, said geosynchronous satellites having a first position above a service area, comprising:

a first stratospheric platform having a substantially fixed second position above a service area having a primary payload, said first stratospheric platform generating communication signals having the first frequency,

a geographically fixed blocking area having a substantially fixed separation angle between said first position and second position less than a predetermined angle, said first stratospheric platform providing the communication signals to the service area outside the blocking area.

10. A system as recited in claim 9 further comprising user terminals having directional antennas.

11. A system as recited in claim 9 further comprising a second stratospheric platform generating a second beam having the first frequency.

12. A system as recited in claim 9 wherein the communication signals are generated from a secondary payload.

13. A system as recited in claim 9 wherein said predetermined angle is about 4 degrees.

14. A system as recited in claim 9 wherein said predetermined angle is about 7 degrees.

15. A method for operating a communications system having a stratospheric platform coordinating with a satellite, said method comprising the steps of:

defining a service area having a geographically fixed blocking area therein, said blocking area having a substantially fixed separation angle between a first position of the satellite and a second position of the stratospheric platform less than a predetermined angle;

generating a first beam using a first frequency directed at the service area with the satellite; and

generating a second beam using the first frequency directed at the service area outside the blocking area from the stratospheric platform.

16. A method as recited in claim 15 wherein said step of generating a second beam comprises the step of generating a second beam from a secondary payload.

17. A method as recited in claim 15 wherein said satellite comprises a geostationary satellite.

18. A method as recited in claim 15 further comprising the step of generating a feeder link.