Method for identifying growth limits of handheld services for mobile satellite communications

• US 6,807,397 B2
• Filed: 10/03/2002
• Issued: 10/19/2004
• Est. Priority Date: 03/23/1999
• Status: Expired due to Term

• Current Assignee: Hughes Electronics Corporation (AT&T, Inc.)
• Original Assignee: Hughes Electronics Corporation (AT&T, Inc.)
• Inventors: Taormina, Frank A., Von Der Embse, Urban A., Chang, Donald C. D., Chang, Ming U., Novak, John I. III, Yung, Kar W., Cheng, David C.
• Primary Examiner(s): Tran, Sinh
• Assistant Examiner(s): RAMOS FELICIANO, ELISEO
• Application Number:
  US10/264,197
• Publication Number:
  US 20030129942A1
• Time in Patent Office: 747 Days
• Field of Search: 455/13-- 1, 455/12.1, 455/11.1, 455/7, 455/427-430, 455/25, 455/501-503, 455/517, 455/98, 455/95, 455/226--22, 455/151.2, 455/445, 370/316, 370/315, 370/351, 370/400, 370/428
• US Class Current: 455/13.1
• CPC Class Codes: B64G 1/1007 Communications satellites
• CPC Class Codes: B64G 1/242 Orbits and trajectories
• CPC Class Codes: H04B 7/18519 Operations control, administration or maintenance

Abstract

Methods for increasing the efficiency of satellite constellation operations are disclosed. The steps of the present invention comprise calculating the maximum number of communications signals that each satellite in the satellite constellation can generate, determining an operational constraint on each satellite, the operational constraint limiting the number of communications signals that each satellite can radiate substantially simultaneously, determining an operational space for each satellite wherein the operational space is defined using the operational constraint and the calculated number of signals, and using the operational space for each satellite in the constellation to determine the operational point for the constellation.

Claims

1. A method of operating a satellite constellation comprising the steps of:

calculating the maximum number of communications signals that each satellite in the satellite constellation can generate;

determining at least one operational constraint on each satellite, the at least one operational constraint limiting the number of communications signals that each satellite can transmit substantially simultaneously;

determining an operational space for each satellite wherein the operational space is defined using information including the at least one operational constraint and the calculated maximum number of communications signals; and

determining an operational point for each satellite in the satellite constellation from the operational space for each satellite in the constellation.

2. The method of claim 1, wherein at least some of the satellites in the satellite constellation are in Medium Earth Orbit (MEO).

3. The method of claim 2, wherein all of the satellites in the satellite constellation are in MEO.

4. The method of claim 1, wherein the operational space determines a maximum number of signals that each satellite can radiate substantially simultaneously without interference.

5. The method of claim 1, further comprising the step of using a communications channel to communicate with multiple communications devices substantially simultaneously.

6. The method of claim 5, wherein the operational space determines a preferred number of satellites to be used in the satellite constellation.

7. The method of claim 6, wherein the operational space relates a set of parameters including:

a number of satellites in the satellite constellation; and

a number of users.

8. The method of claim 7, wherein the users are simultaneous users.

9. The method of claim 7, wherein the set of parameters further includes:

a transmitted power for each of the satellites in the satellite constellation.

10. The method of claim 9, wherein the set of parameters further includes:

a number of channels.

11. The method of claim 7, wherein the number of users includes a first set of users communicating data at a first data rate and a second set of users communicating data at a second data rate higher than the first data rate.

12. The method of claim 11, wherein the first set of users communicate with the satellites using receivers having antennae having a first beamwidth and the second set of users communicate with the satellites using receivers having antennae having a second beamwidth less than the first beamwidth.

13. The method of claim 12, wherein receiver antennae having a second beamwidth track only one of the satellites at a time.

14. The method of claim 1, wherein the communications signals comprise radio frequency (RF) communications signals.

15. The method of claim 1, wherein the communications signals comprise optical communications signals.

16. An apparatus for operating a satellite constellation, comprising:

means for calculating the maximum number of communications signals that each satellite in the satellite constellation can generate;

means for determining at least one operational constraint on each satellite, the at least one operational constraint limiting the number of communications signals that each satellite can transmit substantially simultaneously;

means for determining an operational space for each satellite wherein the operational space is defined using information including the at least one operational constraint and the calculated maximum number of communications signals; and

means for determining an operational point for each satellite in the satellite constellation from the operational space for each satellite in the constellation.

17. The apparatus of claim 16, wherein at least some of the satellites in the satellite constellation are in Medium Earth Orbit (MEO).

18. The apparatus of claim 17, wherein all of the satellites in the satellite constellation are in MEO.

19. The apparatus of claim 16, wherein the operational space determines a maximum number of signals that each satellite can radiate substantially simultaneously without interference.

20. The apparatus of claim 16, further comprising means for using a communications channel to communicate with multiple communications devices substantially simultaneously.

21. The apparatus of claim 20, wherein the operational space determines a preferred number of satellites to be used in the satellite constellation.

22. The apparatus of claim 21, wherein the operational space relates a set of parameters including:

a number of satellites in the satellite constellation; and

a number of users.

23. The apparatus of claim 22, wherein the users are simultaneous users.

24. The apparatus of claim 22, wherein the set of parameters further includes:

a transmitted power for each of the satellites in the satellite constellation.

25. The apparatus of claim 24, wherein the set of parameters further includes:

a number of channels.

26. The apparatus of claim 22, wherein the number of users includes a first set of users communicating data at a first data rate and a second set of users communicating data at a second data rate higher than the first data rate.

27. The apparatus of claim 26, wherein the first set of users communicate with the satellites using receivers having antennae having a first beamwidth and the second set of users communicate with the satellites using receivers having antennae having a second beamwidth less than the first beamwidth.

28. The apparatus of claim 27, wherein receiver antennae having a second beamwidth track only one of the satellites at a time.

29. The apparatus of claim 16, wherein the communications signals comprise radio frequency (RF) communications signals.

30. The apparatus of claim 16, wherein the communications signals comprise optical communications signals.