DYNAMIC BANDWIDTH RESOURCE ALLOCATION FOR SATELLITE DOWNLINKS

• US 20100315949A1
• Filed: 06/15/2010
• Published: 12/16/2010
• Est. Priority Date: 06/16/2009
• Status: Active Grant

• Current Assignee: ViaSat Incorporated
• Original Assignee: ViaSat Incorporated
• Inventors: Agarwal, Anil
• Granted Patent: US 8,634,296 B2
• Time in Patent Office: Days
• 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 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 method comprising:

identifying an estimated downlink resource unit demand for each of the plurality of beams for a future defined time duration responsive to downlink traffic data for each of the plurality of beams monitored before the future defined time duration;

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

dynamically allocating, responsive to the estimated downlink resource unit demand for each of the plurality of beams, a subset of the amount of allocatable resource units to each of the plurality of beams to generate a per-beam downlink resource unit allocation for the future defined time duration;

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

dynamically allocating, 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.

2. The method of claim 1, wherein identifying an estimated downlink resource unit demand for each of the plurality of beams comprises:

measuring, on the satellite, an amount of traffic directed to each beam.

3. The method of claim 1, wherein identifying an estimated downlink resource unit demand for each of the plurality of beams comprises:

receiving traffic measurements from at least a subset of the terminals in each beam.

4. The method of claim 3, wherein,

the traffic measurements are received at a ground-based network control center;

and

the dynamic allocation among the plurality of beams is performed by the ground-based network control center.

5. The method of claim 1, wherein identifying an estimated downlink resource unit demand for each of the plurality of beams comprises:

measuring queue sizes attributable to each beam.

6. The method of claim 1, wherein identifying an estimated downlink resource unit demand for each of the plurality of beams comprises:

calculating dropped packets for each beam.

7. The method of claim 1, further comprising:

identifying, 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 for each beam among the plurality of traffic classes.

8. The method of claim 1, further comprising:

identifying, 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 8, wherein the relative allocation among the plurality of traffic classes is different in each modulation and coding group within a beam of the plurality of beams.

10. The method of claim 1, wherein identifying an estimated downlink resource unit demand for each of a plurality of modulation and coding groups in a beam of the plurality of beams comprises:

receiving link condition data from at least a subset of the terminals within the beam.

11. The method of claim 1, wherein the dynamic allocation among beams comprises:

dynamically changing the per-beam resource unit allocation among beams, wherein the amount allocated for at least a subset of the plurality of beams for the future defined time duration is different from an allocated amount of requested resource units for a prior time duration for the at least the subset of beams, the prior time duration substantially equal in length to the future defined time duration.

12. 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 beam estimation module configured to identify an estimated downlink resource unit demand for each of the plurality of beams for a future defined time duration responsive to downlink traffic data for each of the plurality of beams monitored before the future defined time duration;

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

a resource allocation module, in communication with the beam estimation module and the modulation and coding group estimation module, and configured to;

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

dynamically allocate, responsive to the estimated downlink resource unit demand for each of the plurality of beams, a subset of the amount of allocatable resource units to each of the plurality of beams to generate a changed per-beam downlink resource unit allocation for the future defined time duration; and

dynamically 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.

13. The system of claim 12, wherein the beam estimation module is configured to identify an estimated downlink resource unit demand for each of the plurality of beams by receiving a measurement taken on the satellite identifying an amount or other rate of traffic directed to each beam.

14. The system of claim 12, wherein the beam estimation module is configured to identify an estimated downlink resource unit demand for each of the plurality of beams by

receiving traffic measurements made by at least a subset of the terminals in each beam measuring amount of traffic received from the satellite.

15. The system of claim 12, wherein at least a portion of the system comprises a ground-based network control center.

16. The system of claim 12, wherein the beam estimation module is configured to identify an estimated downlink resource unit demand for each of the plurality of beams by measuring average queue sizes at the satellite attributable to each beam.

17. The system of claim 12, wherein the beam estimation module is further configured to identify an estimated downlink resource unit demand for each of the plurality of beams by calculating a number of dropped packets destined for each downlink beam, the dropped packets occurring at the satellite or at a gateway transmitting to the satellite.

18. The system of claim 12, further comprising:

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

wherein the resource allocation module is further configured to allocate the allocated resource units for each beam among the plurality of traffic classes responsive to the traffic class estimation.

19. The system of claim 18, wherein the relative allocation among the plurality of traffic classes is different in each beam of the plurality of beams.

20. The system of claim 12, further comprising:

a traffic class estimation module, in communication with the resource allocation module, and configured to identify, within 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

wherein the resource allocation module is further configured to allocate 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 responsive to the traffic class estimation.

21. The system of claim 12, wherein the modulation and coding group estimation module is configured to identify an estimated downlink resource unit demand for each of a plurality of modulation and coding groups in a beam of the plurality of beams by receiving a requested modulation and coding group identification from at least a subset of the terminals within the beam.

22. 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 identifying an estimated downlink resource unit demand for each of the plurality of beams for a future defined time duration responsive to downlink traffic data for each of the plurality of beams monitored before the future defined time duration;

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

means for allocating, responsive to the estimated downlink resource unit demand for each of the plurality of beams, a subset of the amount of allocatable resource units to each of the plurality of beams to generate a per-beam downlink resource unit allocation for the future defined time duration;

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

means for allocating, 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.

23. The device of claim 22, wherein the device comprises the satellite.

24. 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;

identify an estimated downlink resource unit demand for each of the plurality of beams for a future defined time duration responsive to downlink traffic data for each of the plurality of beams monitored before the future defined time duration;

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

dynamically allocate, responsive to the estimated downlink resource unit demand for each of the plurality of beams, a subset of the amount of allocatable resource units to each of the plurality of beams to generate a changed per-beam downlink resource unit allocation for the future defined time duration.

25. A method 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 method comprising:

aggregating 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.

26. The method of claim 25, further comprising:

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

27. The method of claim 25, 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.

28. The method of claim 25, further comprising:

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

29. The method of claim 25, further comprising:

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

30. The method of claim 25, further comprising:

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

31. The method of claim 25, further comprising:

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

allocating, 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.

32. The method of claim 31, further comprising:

identifying, 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.

33. The method of claim 25, further comprising:

identifying, 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, 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.

34. The method of claim 25, further comprising:

identifying, 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 for each beam among the plurality of traffic classes.

35. The method of claim 25, further comprising:

identifying, 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, 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.

36. The method of claim 25, further comprising:

determining 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.

37. The method of claim 25, wherein the method is performed by a satellite.

38. The method of claim 25, wherein the method is performed by a network control center.

39. 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.

40. The system of claim 39, 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.

41. The system of claim 39, wherein the downlink beam measurement module is further configured to:

measuring 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.

42. The system of claim 39, 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.

43. The system of claim 39, 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.

44. The system of claim 39, 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.

45. The system of claim 39, 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.

46. The system of claim 39, 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.

47. The system of claim 39, wherein the system comprises a network control center.

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

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

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

means for allocating 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

means for 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.

49. The device of claim 48, wherein the device comprises a satellite.

50. 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.

51. 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 modulator serving a plurality of the beams;

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

identifying, responsive to the determination that the traffic load exceeds the load threshold, one or more of the plurality of beams serving 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.

52. The method of claim 51, further comprising:

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

53. The method of claim 52, wherein the selecting comprises:

selecting the beam and 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.

54. The method of claim 52, wherein the selecting comprises:

selecting the beam and 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.

55. The method of claim 52, wherein the selecting comprises:

selecting the beam and 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.

56. The method of claim 52, wherein the identifying further comprises:

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

57. The method of claim 56, wherein a selected beam of the one or more beams serving the second modulator is switched to the first modulator concurrently with a selected beam of the one or more beams serving the first modulator being switched to the second modulator.

58. The method of claim 51, further comprising:

assigning a selected beam of the one or more beams of the first modulator to the second modulator.

59. The method of claim 58, wherein the assigning the selected beam comprises:

assigning a first modulation and coding group of the selected beam of the one or more beams of the first modulator to the second modulator, while a second modulation and coding group of the selected beam of the one or more beams of the first modulator remains assigned to the first modulator.

60. The method of claim 51, wherein,

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

and

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

61. The method of claim 51, wherein the method is performed by the satellite for rebalancing downlink resources.

62. The method of claim 51, wherein the method is performed by a ground-based network control center for rebalancing downlink resources.

63. A system for modulator balancing in a multi-beam satellite communications network, the system comprises:

a monitoring module configured to;

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

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

a rebalancing evaluation module, in communication with the monitoring module, and configured to determine whether one or more of the plurality of beams serving 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

a selection module, in communication with the rebalancing evaluation module, and configured to select a beam of the one or more of the plurality of beams to be assigned to the second modulator.

64. The system of claim 63, wherein the rebalancing evaluation module comprises a comparator configured to:

identify the beam and 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.

65. The system of claim 63, wherein the rebalancing evaluation module comprises a comparator configured to:

identify the beam and 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.

66. The system of claim 63, wherein the selection module is further configured to:

select one or more of a plurality of beams serving the second modulator to be moved to the first modulator to maintain the traffic load on the second modulator below a load threshold for the second modulator.

67. The system of claim 66, further comprising a switching module, communicatively coupled with the selection module, and configured to concurrently switch the selected beam of the one or more beams serving the second modulator to the first modulator and the selected beam of the one or more beams serving the first modulator to the second modulator.

68. The system of claim 63, wherein the system comprises the satellite, a ground-based network control center, or a combination thereof.

69. 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 the satellite, the modulator serving a plurality of the beams;

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 of the plurality of beams serving 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

rebalancing beam assignments for at least a subset of the plurality of modulators.

70. The method of claim 69, 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.

71. The method of claim 69, 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.

72. The method of claim 69, 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.

73. The method of claim 69, wherein the determining whether one or more of the plurality of beams serving 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 comprises:

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

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

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

means for monitoring a traffic load on a first modulator of a plurality of modulators on the 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 identifying, responsive to the determination that the traffic load exceeds the load threshold, one or more of the plurality of beams serving 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.

75. A system for assigning downlink frequency channels in a multi-beam satellite communications system, the system comprising:

a frequency channel eligibility module configured to identify a number of eligible downlink frequency channels for each of a plurality of modulation and coding groups;

a resource estimation module configured to estimate downlink resource unit demand for each of the plurality of modulation and coding groups; and

a frequency channel assignment module, in communication with the frequency channel eligibility module and the resource estimation module, and configured to select a modulation and coding group for frequency channel assignment in an order corresponding to the number of eligible downlink frequency channels and the estimated downlink resource unit demand for each of the plurality of modulation and coding groups.

76. The system of claim 75, wherein,

the frequency channel eligibility module is further configured to identify a number of eligible downlink frequency channel sizes for each of the plurality of modulation and coding groups;

and

the frequency channel assignment module is further configured to select the modulation and coding group for frequency channel assignment in an order corresponding to the number of eligible downlink frequency channel sizes.

77. The system of claim 75, wherein,

the resource estimation module is configured to estimate downlink resource unit demand by identifying a cumulative guaranteed downlink rate for each of the plurality of modulation and coding groups.

78. The system of claim 75, wherein,

the resource estimation module is configured to estimate downlink resource unit demand by identifying a measured downlink traffic rate in excess of the cumulative guaranteed downlink rate for each of the plurality of modulation and coding groups for a past defined time period;

and

the frequency channel assignment module is further configured to;

assign first frequency channel time slots to the modulation and coding groups to fulfill the cumulative guaranteed downlink rate for each of the plurality of modulation and coding groups; and

assign second frequency channel time slots, subsequent to the first frequency channel time slot assignment, to the modulation and coding groups to fulfill the measured downlink traffic rate.

79. The system of claim 75, wherein the resource estimation module is configured to estimate downlink resource unit demand by measuring a downlink traffic load for each of the plurality of modulation and coding groups for a past defined time period.

80. The system of claim 75, wherein the frequency channel assignment module is configured to assign a frequency channel and time slot to the selected modulation and coding group.

81. The system of claim 80, wherein the frequency channel assignment module is configured to identify the frequency channel for assignment by identifying an eligible frequency channel with a largest time allocation remaining among eligible frequency channels.

82. The system of claim 80, wherein the frequency channel assignment module is configured to identify the frequency channel for assignment by identifying an eligible frequency channel with fewer modulation and coding group assignments than other eligible frequency channels.

83. The system of claim 80, wherein the frequency channel eligibility module is configured to identify eligible downlink frequency channels responsive to a beam reuse pattern constraint.

84. A method for assigning downlink frequency channels in a multi-beam satellite communications system, the method comprising:

identifying a number of eligible downlink frequency channels for each of a plurality of modulation and coding groups;

estimating downlink resource unit demand for each of the plurality of modulation and coding groups; and

selecting modulation and coding groups for frequency channel assignment in an order corresponding to the number of eligible downlink frequency channels and the estimated downlink resource unit demand for each of the plurality of modulation and coding groups.

85. The method of claim 84, further comprising:

identifying a number of eligible downlink frequency channel sizes for each of a plurality of modulation and coding groups, wherein the modulation and coding groups are further selected for frequency channel assignment in an order corresponding to the number of eligible downlink frequency channel sizes identified for each group.

86. The method of claim 84, wherein the estimating comprises:

identifying a cumulative guaranteed downlink rate for each of the plurality of modulation and coding groups.

87. The method of claim 86, wherein the estimating further comprises:

identifying a measured downlink traffic rate in excess of the cumulative guaranteed downlink rate for each of the plurality of modulation and coding groups for a past defined time period.

88. The method of claim 87, further comprising:

assigning first frequency channel time slots to the modulation and coding groups to fulfill the cumulative guaranteed downlink rate for each of the plurality of modulation and coding groups; and

assigning second frequency channel time slots, subsequent to the first frequency channel time slot assignment, to the modulation and coding groups to fulfill the measured downlink traffic rate.

89. The method of claim 84, wherein the estimating comprises:

measuring a downlink traffic load for each of the plurality of modulation and coding groups for a past defined time period.

90. The method of claim 84, further comprising:

assigning a time slot within a selected frequency channel to the selected modulation and coding group.

91. The method of claim 84, further comprising:

identifying the frequency channel for assignment by identifying an eligible frequency channel with a largest contiguous time allocation remaining among eligible frequency channels.

92. The method of claim 84, further comprising:

identifying the frequency channel for assignment by identifying an eligible frequency channel with fewer modulation and coding group assignments than other eligible frequency channels.

93. The method of claim 84, wherein the identifying eligible downlink frequency channels is based at least in part on a beam reuse pattern constraint.

94. A device for assigning downlink frequency channels in a multi-beam satellite communications system, the device comprising:

means for identifying a number of eligible downlink frequency channels for each of a plurality of modulation and coding groups;

means for estimating downlink resource unit demand for each of the plurality of modulation and coding groups; and

means for selecting modulation and coding groups for frequency channel assignment in an order corresponding to the number of eligible downlink frequency channels and the estimated downlink resource unit demand for each of the plurality of modulation and coding groups.

95. The device of claim 94, wherein the means for estimating comprises:

means for identifying a cumulative guaranteed downlink rate for each of the plurality of modulation and coding groups.

96. The device of claim 95, wherein the means for estimating further comprises:

means for measuring a downlink traffic rate and identifying the downlink traffic rate in excess of the cumulative guaranteed downlink rate for each of the plurality of modulation and coding groups for a past defined time period.

97. The device of claim 96, further comprising:

means for assigning first frequency channel time slots to the modulation and coding groups to fulfill the cumulative guaranteed downlink rate for each of the plurality of modulation and coding groups; and

means for assigning second frequency channel time slots, subsequent to the first frequency channel time slot assignment, to the modulation and coding groups to fulfill the measured downlink traffic rate.

98. The device of claim 94, wherein the means for estimating comprises:

means for measuring a downlink traffic load for each of the plurality of modulation and coding groups for a past defined time period.