Dynamic bandwidth resource allocation for satellite downlinks

• US 8,634,296 B2
• Filed: 06/15/2010
• Issued: 01/21/2014
• Est. Priority Date: 06/16/2009
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Agarwal, Anil
• Primary Examiner(s): Thier, Michael
• Assistant Examiner(s): LOUIS, VINNCELAS
• Application Number:
  US12/815,894
• Publication Number:
  US 20100315949A1
• Time in Patent Office: 1,316 Days
• Field of Search: 370229-2351, 370/280, 370/316, 370392-39553, 370/468, 709/217
• US Class Current: 370/235
• 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 performed by a satellite resource control unit for allocating downlink resources in a multi-beam satellite communications network having a plurality of terminals in each of a plurality of beams of a spot-beam satellite, the downlink resources defined in resource units, the satellite resource control unit in communication with the plurality of terminals via the plurality of beams, the method comprising:

aggregating, at the satellite resource control unit, terminal parameter information to identify a cumulative guaranteed downlink rate for each of the plurality of beams;

identifying a measured rate of downlink resource units for each of the plurality of beams for a past time duration;

identifying, for each beam, an amount by which the measured rate exceeds the cumulative guaranteed downlink rate, the amount comprising an excess measured rate;

identifying an amount of allocatable downlink resource units for a future defined time duration for the multi-beam satellite communications network;

allocating a first portion of allocatable downlink resource units among each of the plurality of beams for the future defined time duration, the allocation of the first portion proportionally corresponding to the cumulative guaranteed downlink information rate for each beam; and

allocating, after the first portion is allocated, a remaining second portion of the allocatable downlink resource units among each of the plurality of beams for the future defined time duration, the allocation of the second portion proportionally corresponding to the respective excess measured rate for each beam.

2. The method of claim 1, further comprising:

receiving, at the satellite resource control unit, terminal parameter information from at least of subset of the plurality of terminals in each of the plurality of beams.

3. The method of claim 1, wherein the cumulative guaranteed downlink rate for each of the plurality of beams comprises a combination of a minimum sustained rate and a committed information rate for the plurality of terminals of each respective beam.

4. The method of claim 1, further comprising:

measuring, at the satellite resource control unit, an amount of downlink resource units directed to each beam for the past time duration to determine the measured rate of downlink resource units.

5. The method of claim 1, further comprising:

measuring, at the satellite resource control unit, satellite queue size changes attributable to each beam, wherein the measured rate of downlink resource units accounts for queue size changes.

6. The method of claim 1, further comprising:

calculating, at the satellite resource control unit, dropped packets for each beam, wherein the measured rate of downlink resource units accounts for dropped packets.

7. The method of claim 1, further comprising:

identifying, at the satellite resource control unit, for each of the plurality of beams, an estimated downlink resource unit demand for each of a plurality of modulation and coding groups; and

allocating, at the satellite resource control unit, responsive to the estimated downlink resource unit demand for each of the plurality of modulation and coding groups in each respective beam, the allocated resource units for each beam among the plurality of modulation and coding groups for the future defined time duration.

8. The method of claim 7, further comprising:

identifying, at the satellite resource control unit, in each of the plurality of modulation and coding groups in each of the plurality of beams, an estimated downlink resource unit demand for each of a plurality of traffic classes; and

allocating the allocated resource units in each of the plurality of modulation and coding groups in each of the plurality of beams among the plurality of traffic classes.

9. The method of claim 1, further comprising:

identifying, at the satellite resource control unit, for the cumulative guaranteed downlink rate in each of the plurality of beams, an amount associated with each of a plurality of modulation and coding groups; and

allocating, at the satellite resource control unit, responsive to the estimated downlink resource unit demand for each of the plurality of modulation and coding groups in each respective beam, the allocated resource units for the cumulative guaranteed downlink rate for each beam among the plurality of modulation and coding groups for the future defined time duration.

10. The method of claim 1, further comprising:

identifying, at the satellite resource control unit, in each of the plurality of beams, an estimated downlink resource unit demand for each of a plurality of traffic classes; and

allocating, at the satellite resource control unit, the allocated resource units for each beam among the plurality of traffic classes.

11. The method of claim 1, further comprising:

identifying, at the satellite resource control unit, for the cumulative guaranteed downlink rate in each of the plurality of beams, an amount associated with each of a plurality of traffic classes; and

allocating, at the satellite resource control unit, responsive to the estimated downlink resource unit demand for each of the plurality of traffic classes in each respective beam, the allocated resource units for the cumulative guaranteed downlink rate for each beam among the plurality of traffic classes for the future defined time duration.

12. The method of claim 1, further comprising:

determining, at the satellite resource control unit, whether a sufficient amount of the allocatable resource units remain to satisfy an allocation associated with the excess measured rate; and

when there is not a sufficient amount of allocatable resource units remaining to satisfy an allocation associated with the excess measured rate, allocating a remainder of the allocatable resource units among the plurality of beams according to a fairness policy.

13. The method of claim 1, wherein the satellite resource control unit is located on the spot-beam satellite.

14. The method of claim 1, wherein the satellite resource control unit is located at a network control center.

15. A system for allocating downlink resources in a multi-beam satellite communications network having a plurality of terminals in each of a plurality of beams, the downlink resources defined in resource units, the system comprising:

a terminal parameter module configured to aggregate terminal parameter information to identify a cumulative guaranteed downlink rate for each of the plurality of beams;

a downlink beam measurement module, in communication with the terminal parameter module, and configured to;

identify a measured rate of downlink resource units for each of the plurality of beams for a past time duration;

identify, for each beam, an amount by which the measured rate exceeds the cumulative guaranteed downlink rate, the amount comprising an excess measured rate;

a resource allocation module, in communication with the terminal parameter module and the beam measurement module, and configured to;

identify an amount of allocatable downlink resource units for a future defined time duration for the multi-beam satellite communications network;

allocate a first portion amount of allocatable downlink resource units among each of the plurality of beams for the future defined time duration, the allocation of the first portion proportionally corresponding to the cumulative guaranteed downlink information rate for each beam; and

allocate, after the first portion is allocated, a remaining second portion of the allocatable downlink resource units among each of the plurality of beams for the future defined time duration, the allocation of the second portion proportionally corresponding to the respective excess measured rate for each beam.

16. The system of claim 15, wherein the terminal parameter module is further configured to:

receive terminal parameter information from at least of subset of the plurality of terminals in each of the plurality of beams.

17. The system of claim 15, wherein the downlink beam measurement module is further configured to:

measure an amount of downlink resource units directed to each beam for the past time duration to determine the measured rate of downlink resource units, wherein the past time duration is substantially equal in length to the future time duration.

18. The system of claim 15, wherein the downlink beam measurement module is further configured to:

measure satellite queue size changes attributable to each beam for the past time duration; and

calculate dropped packets for each beam for the past time duration, wherein the measured rate of downlink resource units accounts for the queue size changes and the dropped packets.

19. The system of claim 15, further comprising:

a modulation and coding group estimation module, in communication with the resource allocation module, and configured to identify, in each of the plurality of beams, an estimated downlink resource unit demand for each of a plurality of modulation and coding groups,

wherein the resource allocation module is further configured to allocate, responsive to the estimated downlink resource unit demand for each of the plurality of modulation and coding groups in each respective beam, the allocated resource units for each beam among the plurality of modulation and coding groups for the future defined time duration.

20. The system of claim 15, further comprising:

a traffic class estimation module, in communication with the resource allocation module, and configured to identify, in each of the plurality of beams, an estimated downlink resource unit demand for each of a plurality of traffic classes; and

wherein the resource allocation module is further configured to allocate, responsive to the estimated downlink resource unit demand for each of the plurality of classes in each respective beam, the allocated resource units for each beam among the plurality of traffic classes.

21. The system of claim 15, wherein the resource allocation module is further configured to:

determine whether a sufficient amount of the allocatable resource units remain to satisfy an allocation associated with the excess measured rate; and

when there is not a sufficient amount of allocatable resource units remaining to satisfy an allocation associated with the second portion, allocating a remainder of the allocatable resource units among the plurality of beams according to a fairness policy.

22. The system of claim 15, wherein the resource allocation module is configured to allocate the first portion by:

allocating a minimum sustained rate for each of the plurality of beams; and

allocating, subsequent to the minimum sustained rate allocation, a committed information rate for each of the plurality of beams.

23. The system of claim 15, wherein the system comprises a network control center.

24. A device for allocating downlink resources in a multi-beam satellite communications network having a plurality of terminals in each of a plurality of beams, the downlink resources defined in resource units, the device comprising:

means for aggregating terminal parameter information to identify a cumulative guaranteed downlink rate for each of the plurality of beams;

means for downlink beam measurement, wherein the means for downlink beam measurement identifies a measured rate of downlink resource units for each of the plurality of beams for a past time duration and identifies, for each beam, an amount by which the measured rate exceeds the guaranteed downlink rate, the amount comprising an excess measured rate;

means for resource allocation, wherein the means for resource allocation identifies an amount of allocatable downlink resource units for a future defined time duration for the multi-beam satellite communications network, allocates a first portion amount of allocatable downlink resource units among each of the plurality of beams for the future defined time duration, the allocation of the first portion proportionally corresponding to the cumulative guaranteed downlink information rate for each beam, and allocates, after the first portion is allocated, a remaining second portion of the allocatable downlink resource units among each of the plurality of beams for the future defined time duration, the allocation of the second portion proportionally corresponding to the respective excess measured rate for each beam.

25. The device of claim 24, wherein the device comprises a satellite.

26. A satellite communications system for allocating downlink resources in a multi-beam satellite communications network, the downlink resources defined in resource units, the system comprising:

a plurality of terminals in each of a plurality of beams; and

a resource allocator system in communication via satellite with each of the plurality of terminals in each of the plurality of beams, the resource allocator system configured to;

aggregate terminal parameter information to identify a cumulative guaranteed downlink rate for each of the plurality of beams;

identify a measured rate of downlink resource units for each of the plurality of beams for a past time duration;

identify, for each beam, an amount by which the measured rate exceeds the guaranteed downlink rate, the amount comprising an excess measured rate;

identify an amount of allocatable downlink resource units for a future defined time duration for the multi-beam satellite communications network;

allocate a first portion amount of allocatable downlink resource units among each of the plurality of beams for the future defined time duration, the allocation of the first portion proportionally corresponding to the cumulative guaranteed downlink information rate for each beam; and

allocate, after the first portion is allocated, a remaining second portion of the allocatable downlink resource units among each of the plurality of beams for the future defined time duration, the allocation of the second portion proportionally corresponding to the respective excess measured rate for each beam.