Viasat, Inc.

Tachyon, Inc.

Tachyon Networks Incorporated

Utc Fire & Security Americas Corporation, Inc.

Utc Fire & Security Emea Bvba

Donald Wesley Becker

John Hai O'Neill

Mark J Miller

William H Thesling

Matthew D Nimon

Nirmalkumar Velayudhan

Veena Padmanabhan

Arthur Senyue Loh

Karl E Moerder

Aaron J Mendelsohn

David H Irvine

Bruce L Carneal

James E Petranovich

William H Edwards

Martin Paul Robotham

Min Zhu

William E L Leigh

Remberto Martin

Changping Li

Paul Schatz

Richard Blount

Dave Dopson

Timothy Steven Potter

Morris Stoops

Vitaliy Sivetsiy

Vladimir Geyts

Joseph Peter Calinski

Bruce Montgormery

Galera Andres Cordoba

Marty Camins

Richard P Tucker

Timothy Stevens Potter

Bruce Ray Montgomery

Karl Moerder

Bruce Carneal

John H O'neill

Jeffrey Wyman

Martin Camins

Systems and methods are described for robust scheduling of beam switching patterns in satellite communications systems. Embodiments operate in context of a hub-spoke satellite communications architecture having a number of gateway terminals servicing large numbers of user terminals over a number of spot beams. The satellite includes switching subsystems that distribute capacity to the user beams from multiple of the gateway terminals in a shared manner according to a beam group switching pattern. The beam group switching pattern is robustly formulated to continue distributing capacity during gateway outages (e.g., when one or two gateway terminals are temporarily non-operational due to rain fade, equipment failure, etc.). For example, the beam group switching pattern can be formulated to minimize worst-case degradation of capacity across user beams, to prioritize certain beams or beam groups, etc.

Robust beam switch scheduling

Systems and methods are described for enabling flexible signal pathways within a satellite of a satellite communications system. For example, a pathway selection subsystem in a bent-pipe satellite enables a flexible arrangement of non-processed signal pathways that couple uplink antenna ports with downlink antenna ports via uplink and downlink pathway selectors. The pathway selectors can be dynamically reconfigured (e.g., on orbit), so that the configuration of the pathway selectors at one time can form one set of signal pathways between respective uplink and downlink antenna ports, and the configuration at another time can form a different set of signal pathways between respective uplink and downlink antenna ports. The pathway selection subsystem can have a simulcast mode which, when active, couples each of at least one of the uplink antenna ports with multiple of the user downlink antenna ports to form one or more simulcast signal pathways.

Flexible intra-satellite signal pathways

Embodiments provide techniques for dynamic spot beam assignment in a geostationary satellite communications network. For example, a ground processing node in the geostationary satellite network can monitor spot beam coverage area location and can detect a beam drift trigger indicating present drifting of one or more coverage areas. Ground terminals can be identified as serviced by spot beams associated with the drifting coverage area(s) and as experiencing a signal quality impact from the drifting. The ground terminal node can compute an update to a beam assignment map having a reassignment of the identified user terminals from their presently servicing spot beams to another of the spot beams in a manner that seeks to address at least some of the signal quality impact identified as associated with the drifting. Some embodiments further account for load balancing, and/or other factors, and/or can maintain stateful communications between the reassigned user terminals and the geostationary satellite.

Dynamic satellite beam assignment

Systems and methods are described synchronizing communications frames and their respective time slots for satellite communications architectures having multiple satellites in the same orbital slot in such a way that addresses inter-satellite inter-beam interference. In some embodiments, the first and second satellites communicate with a respective number of ground terminals (e.g., gateway and user terminals) according to first and second satellite time slots, respectively. The satellites maintain relative positions in their orbital slot to manifest a maximum path delay difference between first and second path delays, the first path delay being between the first ground terminals and the first satellite, and the second path delay being between the first ground terminals and the second satellite. A synchronization system can offset the first satellite time slots from the second satellite time slots as a function of the maximum path delay difference.

Tandem satellite frame synchronization

Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via a satellite. A wireless signal may include a series of physical layer frames, each frame including a physical layer header and payload. The received signal is digitized and processed using various novel physical layer headers and related techniques to synchronize the physical layer frames and recover data from physical layer headers for purposes of demodulation and decoding.

False lock detection for physical layer frame synchronization

Symbol timing acquisition is described for a wireless broadband signal received at a user terminal from a gateway via a satellite. In-phase and quadrature channels of the wireless signal may each be sampled at a rate of one sample per symbol. The samples may be interpolated to generate an early interpolation and a late interpolation for each of the samples. A difference measurement is obtained between the early interpolation and the late interpolation for a set of the samples. A number of the difference measurements may be averaged, and symbol timing may be modified based on the average. This process may be continued on an iterative basis to acquire symbol timing.

Symbol timing acquisition using early-late interpolation

Embodiments provide methods, apparatuses, and systems for efficient control signaling over shared communication channels with wide dynamic range. Some embodiments includes a gateway configured to encode and to transmit multiple physical layer headers, including a first physical layer header and a second physical layer header. The first physical layer header may span a first length and represent a first modcode; the second physical layer header may span a second length and represent a second modcode. The second length may be longer than the first length. Embodiments may include multiple terminals in wireless communication with the gateway via satellite, including a first terminal configured to decode the first physical layer header and to determine the first modcode. Embodiments may include a second terminal configured to decode the second physical layer header and determine the second modcode.

Efficient control signaling over shared communication channels with wide dynamic range

Systems, devices, processors, and methods are described which may be used for the reception of a wireless broadband signal at a user terminal from a gateway via satellite. A physical layer header may be identified, the header including a number of subcode blocks. A phase may be estimated for each of the subcode blocks, and intra-header phase differences may be calculated. The intra-header phase differences may be used to calculate a frequency error, which may be corrected. Frequency errors may be monitored and, when such errors fall below a threshold level, an alternative inter-frame frequency error tracking method may be used.

Delta-theta frequency estimation

A method for determining attenuation settings across carriers in a return link bandwidth of a user terminal comprises determining a first attenuation setting for a user terminal at a first transmission frequency, where the first attenuation setting is based on a first signal quality metric value of a first message sent from the user terminal at the first transmission frequency. The method also comprises determining a second attenuation setting for the user terminal at a second transmission frequency, where the second attenuation setting is based on a second signal quality metric value of a second message sent from the user terminal at the second transmission frequency. The method also comprises determining the attenuation settings across the carriers in the return link bandwidth of the user terminal based on the first attenuation setting and the second attenuation setting.

MF-TDMA satellite link power control

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Rancho Santa Fe, CA, United States of America

Donald Wesley Becker