Dynamic bandwidth resource allocation for satellite downlinks

• US 10,020,875 B2
• Filed: 07/26/2017
• Issued: 07/10/2018
• Est. Priority Date: 06/16/2009
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Agarwal, Anil
• Primary Examiner(s): Louis, Vinncelas
• Application Number:
  US15/660,406
• Publication Number:
  US 20180062733A1
• Time in Patent Office: 349 Days
• Field of Search: None
• CPC Class Codes: H04B 7/0408 using two or more beams, i.e. beam diversity
• CPC Class Codes: H04B 7/18515 Transmission equipment in satellites or space-based relays
• CPC Class Codes: H04B 7/18539 Arrangements for managing radio, resources, i.e. for establishing or releasing a connection
• CPC Class Codes: H04B 7/2123 Variable assignment, e.g. demand assignment
• CPC Class Codes: H04B 7/22 Scatter propagation systems , e.g. ionospheric, tropospheric or meteor scatter
• CPC Class Codes: H04L 5/0096 Indication of changes in allocation
• CPC Class Codes: H04L 67/61 taking into account QoS or priority requirements
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/046 the resource being in the space domain, e.g. beams
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

Satellite communications systems, methods, and related devices are described. In one embodiment, a satellite communications system is configured to dynamically allocate bandwidth among different downlink beams. The satellite may receive and compile traffic measurements and terminal parameters. The satellite may be configured with different downlink beam coverage areas, and may dynamically allocate downlink bandwidth and particular frequency channels to different beam coverage areas based on the measurements and parameters. The satellite may also assign frequency channels and time slots based on such measurements and parameters.

Claims

1. A method for modulator balancing in a multi-beam satellite communications network, the method comprising:

monitoring a traffic load on a first modulator of a plurality of modulators on a satellite, the first modulator serving a plurality of beams of the satellite;

determining that the traffic load exceeds a load threshold for the first modulator;

identifying, responsive to the determination that the traffic load exceeds the load threshold, one or more of the plurality of beams served by the first modulator that may be moved to a second modulator of the plurality of modulators while maintaining a traffic load on the second modulator below a load threshold for the second modulator; and

selecting a beam of the one or more of the plurality of beams to be moved to the second modulator.

2. The method of claim 1, wherein the selecting comprises:

selecting the beam and the second modulator responsive to a determination that a combined traffic load metric on the first modulator and the second modulator after moving the selected beam to the second modulator is lower than a combined traffic load metric from moving one or more of the plurality of beams to one or more other modulators of the plurality of modulators.

3. The method of claim 1, wherein the selecting comprises:

selecting the beam and the second modulator responsive to a determination that a combined traffic load metric on the first modulator and the second modulator after moving the selected beam to the second modulator is lower than a combined traffic load metric from moving the selected beam to one or more other modulators of the plurality of modulators.

4. The method of claim 1, wherein the selecting comprises:

selecting the beam and the second modulator responsive to a determination that a combined traffic load metric on the first modulator and the second modulator after moving the selected beam to the second modulator is lower than a combined traffic load metric from moving other of the plurality of beams to the second modulator.

5. The method of claim 1, wherein the identifying further comprises:

identifying one or more of a second plurality of beams served by the second modulator that may be moved to the first modulator to maintain the traffic load on the second modulator below the load threshold for the second modulator.

6. The method of claim 5, wherein the selected beam of the one or more of the second plurality of beams served by the second modulator is switched to the first modulator concurrently with the selected beam of the plurality of beams served by the first modulator being switched to the second modulator.

7. The method of claim 1, wherein,

the first modulator outputs a waveform for only one carrier at any given time period;

and

the second modulator outputs a waveform for only one carrier at any given time period.

8. The method of claim 1, wherein the method is performed by the satellite for rebalancing downlink resources.

9. The method of claim 1, wherein the method is performed by a ground-based network control center for rebalancing downlink resources.

10. The method of claim 1, wherein the identifying one or more of the plurality of beams served by the first modulator that may be moved to the second modulator of the plurality of modulators while maintaining the traffic load on the second modulator below the load threshold for the second modulator comprises:

determining that none of the plurality of beams served by the first modulator may be moved to the second modulator while maintaining a measured traffic load on the second modulator below the load threshold for the second modulator; and

identifying that the one or more of the plurality of beams served by the first modulator may be moved to the second modulator while maintaining a committed information rate on the second modulator below the load threshold for the second modulator.

11. A system for modulator balancing in a multi-beam satellite communications network, comprising:

means for monitoring a traffic load on a first modulator of a plurality of modulators on a satellite, the first modulator serving a plurality of beams of the satellite; and

means for determining that the traffic load exceeds a load threshold for the first modulator;

means for determining whether one or more of the plurality of beams served by the first modulator may be moved to a second modulator of the plurality of modulators while maintaining a traffic load on the second modulator below a load threshold for the second modulator; and

means for selecting a beam of the one or more of the plurality of beams to be assigned to the second modulator.

12. The system of claim 11, wherein the means for determining whether the one or more of the plurality of beams served by the first modulator may be moved to the second modulator identifies the beam and the second modulator responsive to a determination that a combined traffic load metric on the first modulator and the second modulator after moving the selected beam to the second modulator is lower than a combined traffic load metric from moving one or more of the plurality of beams to one or more other modulators of the plurality of modulators.

13. The system of claim 11, wherein the means for determining whether the one or more of the plurality of beams served by the first modulator may be moved to the second modulator identifies the beam and the second modulator responsive to a determination that a combined traffic load metric on the first modulator and the second modulator after moving the selected beam to the second modulator is lower than a combined traffic load metric from moving other of the plurality of beams to the second modulator.

14. The system of claim 11, wherein the means for selecting selects one or more of a second plurality of beams served by the second modulator to be moved to the first modulator to maintain the traffic load on the second modulator below the load threshold for the second modulator.

15. The system of claim 14, further comprising means for concurrently switching the selected beam of the one or more of the second plurality of beams served by the second modulator to the first modulator and the selected beam of the one or more of the plurality of beams served by the first modulator to the second modulator.

16. The system of claim 11, wherein the system comprises the satellite, a ground-based network control center, or a combination thereof.

17. A method for modulator balancing in a multi-beam satellite communications network, the method comprising:

monitoring a traffic load on a first modulator of a plurality of modulators on a satellite, the first modulator serving a plurality of beams of the satellite;

determining that the traffic load exceeds a load threshold for the first modulator;

determining, responsive to the determination that the traffic load exceeds the load threshold, whether one or more modulation and coding groups of a beam of the plurality of beams served by the first modulator may be reassigned to a second modulator of the plurality of modulators while maintaining a traffic load on the second modulator below a load threshold for the second modulator; and

rebalancing beam assignments for at least a subset of the plurality of modulators, wherein the rebalancing comprises assigning the one or more modulation and coding groups of the beam of the plurality of beams served by the first modulator to the second modulator.

18. The method of claim 17, further comprising:

measuring data traffic on each of the plurality of beams served by the first modulator over a past time duration, wherein the traffic load comprises the measured data traffic for each of the plurality of beams.

19. The method of claim 17, further comprising:

aggregating a committed information rate for data traffic on each of the plurality of beams served by the first modulator, wherein the traffic load comprises the aggregated committed information rate for the plurality of beams.

20. The method of claim 17, wherein,

the determining that the traffic load exceeds the load threshold for the first modulator comprises comparing the load threshold to measured data traffic over a past time duration;

and

the traffic load on the second modulator comprises a committed information rate for data traffic for the plurality of beams of the second modulator.

21. The method of claim 17, wherein the determining whether one or more modulation and coding groups of the beam of the plurality of beams served by the first modulator may be reassigned to the second modulator of the plurality of modulators while maintaining a traffic load on the second modulator below the load threshold for the second modulator comprises:

determining that none of the modulation and coding groups of the beam of the plurality of beams served by the first modulator may be moved to the second modulator while maintaining a measured traffic load on the second modulator below the load threshold for the second modulator; and

identifying that the one or more modulation and coding groups of the beam of the plurality of beams served by the first modulator may be reassigned to the second modulator while maintaining a committed information rate on the second modulator below the load threshold for the second modulator.

22. The method of claim 17, wherein the rebalancing comprises assigning a first modulation and coding group of the beam of the plurality of beams served by the first modulator to the second modulator, while a second modulation and coding group of the beam of the plurality of beams served by the first modulator remains assigned to the first modulator.

23. A system for modulator balancing in a multi-beam satellite communications network, comprising:

means for monitoring a traffic load on a first modulator of a plurality of modulators on a satellite, the modulator serving a plurality of beams;

means for determining that the traffic load exceeds a load threshold for the first modulator; and

means for determining, responsive to the determination that the traffic load exceeds the load threshold, whether one or more modulation and coding groups of a beam of the plurality of beams served by the first modulator may be moved to a second modulator of the plurality of modulators while maintaining a traffic load on the second modulator below a load threshold for the second modulator; and

means for rebalancing beam assignments for at least a subset of the plurality of modulators, wherein the rebalancing comprises assigning the one or more modulation and coding groups of the beam of the plurality of beams served by the first modulator to the second modulator.

24. The system of claim 23, wherein the means for rebalancing assigns a first modulation and coding group of the beam of the plurality of beams served by the first modulator to the second modulator, while a second modulation and coding group of the beam of the plurality of beams served by the first modulator remains assigned to the first modulator.