Abstract: A satellite communication system uses a plurality of optical feeder links between its ground segment and its space segment and employs spatial diversity transmission, which splits individual user data streams into sub-streams sent across two or more of the optical feeder links such that recovery of the full stream at the receiving end is possible despite impairments affecting individual feeder links over which the stream is split. Further, the system applies beamforming separately with respect to the feeder links, meaning that transmission time alignment is not needed between respective ones of the sub-streams. Spatial diversity transmission occurs in the forward direction or in the return direction or both and may be employed on a conditional basis and dynamically adjusted with respect to individual user terminals, groups of user terminals, or whole populations of user terminals.

Abstract: A satellite communications system and method of operation provide service to pluralities of user terminals in multiple non-overlapping user coverage areas, based on performing ground-based, end-to-end beamforming simultaneously with respect to the multiple user coverage areas. The system provides a number of simultaneous beams in the forward or reverse directions and controlling the allocation of beams to respective user coverage areas determines the capacity allocations for the respective user coverage areas. A multiplicity of transmit/receive paths onboard a satellite in the system supports the end-to-end beamforming and controlling the beam allocations is based on controlling the allocation of such paths to the respective user coverage areas.

Abstract: Methods, systems, and devices for mobile satellite beam resource allocation are described. A communication service may be provided to mobile terminals via respective beamformed spot beams that track movement of the mobile terminals. A central server may perform resource element allocation by determining, for repeating time periods, interference events associated with the beams for a current time period, determining resource elements to associate with the interfering beams for the next time period, and directing reassignment of the beams to the resource elements for the next time period. Each beam may be assigned to one or more resource elements based on a quantity of mobile terminals within the coverage area of the beam or on a desired data rate of the mobile terminals. Power associated with the resource elements may be adjusted based on a data rate or user demand associated with the mobile terminals.

Abstract: A satellite communications network (SCN) advantageously features selective use of diversity and non-diversity service modes, with respect to serving individual user terminals (UTs) using a constellation of non-geosynchronous satellites included in the SCN. For example, with respect to serving any given UT, the SCN may switch from a non-diversity service mode to a diversity service mode, responsive to determining that non-diversity service involves one or more restricted viewing angles. The restricted viewing angles may be learned for the UT location based on past monitoring by the SCN or may be estimated from viewing angle restrictions learned for one or more locations nearby the UT location.

Abstract: A satellite communications system (SCS) (20) implements a beam recentering function (32) that dynamically recenters one or more spot beams (10) with respect to their corresponding nominal beam coverage areas (40), as a component of user scheduling. Updating the beam center target (46) of a spot beam (10) can be understood as adjusting beamforming by the SCS (20) to move the beam center (14) of the spot beam (10), such that maximum signal power of the beam corresponds to different locations within the same nominal beam coverage area over time. In an example embodiment, the SCS (20) uses dynamic beam centering with respect to a plurality of forward user beams (100), with the underlying beamforming being ground-based beamforming, such as end-to-end beamforming, or being satellite-based beamforming, which may be supported by ground-based or satellite-based computation of the dynamically changing beamforming solution.

Abstract: Methods, systems, and devices for individual terminal mobile satellite beam tracking are described. A communication service may be provided to mobile terminals via respective beamformed spot beams that track movement of the mobile terminals. To generate the beamformed spot beams, channel state information based on the locations of the mobile terminals, may be determined based on measurements of signals communicated with the mobile terminals. Beamforming coefficients based on the channel state information may be applied to cause the beamformed spot beams to be centered on the locations of the respective mobile terminals. The beamforming coefficients may be changed periodically so that the beamformed spot beams remain centered on the moving locations of the mobile terminals.

Abstract: Schedulers that allocate resource grants on a slot-by-slot basis within a scheduling epoch or frame can create a front-loading effect where allocations occur more frequently in slots earlier in frames. To address these and other issues, systems and methods are disclosed for scheduling resource grants in a network to improve network transmit power profiles. For example, a scheduler is configured to randomize the order of slots in a scheduling epoch or frame, with different randomizations for different schedulers, to more evenly distribute slots with resource grant allocations to prevent or reduce a front-loading effect. As another example, the scheduler is configured to randomize start times of resource blocks within a slot to prevent or reduce the front-loading effect.

Abstract: Techniques for scheduling a plurality of terminals assigned to a user beam of a satellite communications system involve selecting different beam center targets for the user beam over a succession of scheduling intervals and scheduling respective ones among the terminals over the succession of scheduling intervals according to per-terminal signal-quality metrics that vary with respect to the different beam center targets. Changing the beam center target over the succession of scheduling intervals means that each terminal can experience good, or at least relatively better, signal quality during at least some of the scheduling intervals, which in turn allows a scheduler to schedule respective ones of the terminals primarily on the one or more scheduling intervals in which they experience the good or relatively better signal quality. Benefits flowing from this approach include higher overall capacity for the user beam while maintaining service fairness for the assigned terminals.

Abstract: A satellite communications system and method of operation provides service to pluralities of user terminals in multiple non-overlapping user coverage areas, based on performing ground-based, end-to-end beamforming simultaneously with respect to the multiple user coverage areas. A satellite communications system and method of operation provides service to pluralities of user terminals in multiple non-overlapping user coverage areas, based on performing ground-based, end-to-end beamforming simultaneously with respect to the multiple user coverage areas. The system provides a number of simultaneous beams in the forward or reverse directions and controlling the allocation of beams to respective user coverage areas determines the capacity allocations for the respective user coverage areas.

Abstract: Systems and methods are described that enable user terminals to eliminate or reduce the number of dummy bursts (or bursts with no data) they send. The systems and methods use two burst detectors, a first burst detector that analyzes the physical structure of the signal, and a second burst detector that analyzes the informational structure of the signal. Output from the first burst detector can be used to control operation of a signal decoder that decodes received signals. The second burst detector analyzes output from the signal decoder to determine the second burst indicator. In other words, the first burst detector can be implemented prior to decoding the received signal to provide a first estimate related to the presence or absence of a burst. This can then be used to limit the amount of processing performed by the signal decoder.

Abstract: Schedulers that allocate resource grants on a slot-by-slot basis within a scheduling epoch or frame can create a front-loading effect where allocations occur more frequently in slots earlier in frames. To address these and other issues, systems and methods are disclosed for scheduling resource grants in a network to improve network transmit power profiles. For example, a scheduler is configured to randomize the order of slots in a scheduling epoch or frame, with different randomizations for different schedulers, to more evenly distribute slots with resource grant allocations to prevent or reduce a front-loading effect. As another example, the scheduler is configured to randomize start times of resource blocks within a slot to prevent or reduce the front-loading effect.

Abstract: Systems and methods are described that enable user terminals to eliminate or reduce the number of dummy bursts (or bursts with no data) they send. The systems and methods use two burst detectors, a first burst detector that analyzes the physical structure of the signal, and a second burst detector that analyzes the informational structure of the signal. Output from the first burst detector can be used to control operation of a signal decoder that decodes received signals. The second burst detector analyzes output from the signal decoder to determine the second burst indicator. In other words, the first burst detector can be implemented prior to decoding the received signal to provide a first estimate related to the presence or absence of a burst. This can then be used to limit the amount of processing performed by the signal decoder.

Abstract: Schedulers that allocate resource grants on a slot-by-slot basis within a scheduling epoch or frame can create a front-loading effect where allocations occur more frequently in slots earlier in frames. To address these and other issues, systems and methods are disclosed for scheduling resource grants in a network to improve network transmit power profiles. For example, a scheduler is configured to randomize the order of slots in a scheduling epoch or frame, with different randomizations for different schedulers, to more evenly distribute slots with resource grant allocations to prevent or reduce a front-loading effect. As another example, the scheduler is configured to randomize start times of resource blocks within a slot to prevent or reduce the front-loading effect.

Abstract: A satellite communications system and method of operation provides service to pluralities of user terminals in multiple non-overlapping user coverage areas, based on performing ground-based, end-to-end beamforming simultaneously with respect to the multiple user coverage areas. A satellite communications system and method of operation provides service to pluralities of user terminals in multiple non-overlapping user coverage areas, based on performing ground-based, end-to-end beamforming simultaneously with respect to the multiple user coverage areas. The system provides a number of simultaneous beams in the forward or reverse directions and controlling the allocation of beams to respective user coverage areas determines the capacity allocations for the respective user coverage areas.

Abstract: Schedulers that allocate resource grants on a slot-by-slot basis within a scheduling epoch or frame can create a front-loading effect where allocations occur more frequently in slots earlier in frames. To address these and other issues, systems and methods are disclosed for scheduling resource grants in a network to improve network transmit power profiles. For example, a scheduler is configured to randomize the order of slots in a scheduling epoch or frame, with different randomizations for different schedulers, to more evenly distribute slots with resource grant allocations to prevent or reduce a front-loading effect. As another example, the scheduler is configured to randomize start times of resource blocks within a slot to prevent or reduce the front-loading effect.

Abstract: Described herein are systems, devices, and methods that improve network communication on a high-latency network by using a low-latency network to manage return-link bandwidth. Embodiments of the systems described herein include a user terminal that is communicatively coupled to a high-latency network and a low-latency network. The user terminal is configured to communicate with a gateway routing device over the low-latency network. The user terminal requests return-link bandwidth and the gateway routing device provides a transmission schedule to the user terminal over the low-latency network. The user terminal can be configured to transmit a message over the high-latency network using the scheduled return-link bandwidth.

Abstract: Systems and methods are described that enable user terminals to eliminate or reduce the number of dummy bursts (or bursts with no data) they send. The systems and methods use two burst detectors, a first burst detector that analyzes the physical structure of the signal, and a second burst detector that analyzes the informational structure of the signal. Output from the first burst detector can be used to control operation of a signal decoder that decodes received signals. The second burst detector analyzes output from the signal decoder to determine the second burst indicator. In other words, the first burst detector can be implemented prior to decoding the received signal to provide a first estimate related to the presence or absence of a burst. This can then be used to limit the amount of processing performed by the signal decoder.

Abstract: Schedulers that allocate resource grants on a slot-by-slot basis within a scheduling epoch or frame can create a front-loading effect where allocations occur more frequently in slots earlier in frames. To address these and other issues, systems and methods are disclosed for scheduling resource grants in a network to improve network transmit power profiles. For example, a scheduler is configured to randomize the order of slots in a scheduling epoch or frame, with different randomizations for different schedulers, to more evenly distribute slots with resource grant allocations to prevent or reduce a front-loading effect. As another example, the scheduler is configured to randomize start times of resource blocks within a slot to prevent or reduce the front-loading effect.

Abstract: Described herein are systems, devices, and methods that improve network communication on a high-latency network by using a low-latency network to manage return-link bandwidth. Embodiments of the systems described herein include a user terminal that is communicatively coupled to a high-latency network and a low-latency network. The user terminal is configured to communicate with a gateway routing device over the low-latency network. The user terminal requests return-link bandwidth and the gateway routing device provides a transmission schedule to the user terminal over the low-latency network. The user terminal can be configured to transmit a message over the high-latency network using the scheduled return-link bandwidth.

Abstract: Described herein are systems, devices, and methods that improve network communication on a high-latency network by using a low-latency network to manage return-link bandwidth. Embodiments of the systems described herein include a user terminal that is communicatively coupled to a high-latency network and a low-latency network. The user terminal is configured to communicate with a gateway routing device over the low-latency network. The user terminal requests return-link bandwidth and the gateway routing device provides a transmission schedule to the user terminal over the low-latency network. The user terminal can be configured to transmit a message over the high-latency network using the scheduled return-link bandwidth.