Abstract: In one implementation, load balancing within a constellation of communications satellites is performed. Anticipated positions of satellites are determined. Each satellite is configured to provide multiple beams that define a coverage footprint for the satellite. Based on the anticipated positions of the satellites, it is determined that a first coverage footprint for a first satellite provides primary coverage of a high traffic region and portions of the first coverage footprint for the first satellite also will be covered by coverage footprints for other satellites, Based on these determinations, a beam assignments are defined in which a first subset of beams of the first satellite configured to provide coverage of a first portion of the first coverage footprint are inactive and a second subset of beams of the second satellite are active. The second subset of beams of the second satellite provide coverage within the first portion of the first coverage footprint.

Abstract: According to one implementation of the disclosure, a computer-implemented method of operating a feeder link terminal to locate a satellite in low-Earth orbit includes accessing predicted location information for a satellite in low-Earth orbit and determining an initial position at which to start a scan for the satellite. In addition, the method includes defining a substantially ellipsoidal region to scan for the satellite that includes the initial position, that has a long axis that corresponds to a predicted track of the satellite relative to the feeder link terminal, and that has a shorter axis that corresponds to potential cross-track error of the predicted track of the satellite. The method further includes causing the feeder link terminal to scan the ellipsoidal region for the satellite starting from the initial position.

Abstract: In one implementation, a wireless communications terminal includes a multi-element antenna. In addition, the terminal includes preliminary signal combiners to combine received signals output by corresponding pairs of antenna elements. For each preliminary signal combiner, the signal output by a first of the pair of elements provides a model of interference present in the received signal output by the second of the pair of elements. The preliminary signal combiner is configured to combine the signal output by the first element with the signal output by the second element to produce an initial interference-mitigated signal.

Abstract: In one implementation, an antenna array has a plurality of antenna element, each of which is configured to apply a phase shift to a signal. A beam steering controller is configured to steer a main beam of the antenna by controlling the phase shifts applied by the antenna elements. In addition, the beam steering controller also is configured to detect a failure of an antenna element and, in response to detecting the failure, disable the failed antenna element and modify the phase shifts applied by remaining ones of the antenna elements.

Abstract: In one implementation, a wireless communication terminal includes a sense antenna module configured to sample an interference signal. The wireless communication terminal also includes a primary antenna module configured to receive a desired signal. The sense antenna module has a first polarization type, and the primary antenna module has a second polarization type, substantially orthogonal to the first polarization type of the sense antenna module. In addition, the wireless communication terminal includes at least one signal combiner configured to receive output from the sense antenna module and output from the primary antenna module. The at least one signal combiner is configured to mitigate interference with the desired signal by shifting the phase of the output from the sense antenna module by substantially 180 degrees and combining the phase-shifted output from the sense antenna module with the output of the primary antenna module to produce an interference mitigated signal.

Abstract: In one implementation, a communication device comprising one or more processors is configured to participate in a plurality of talkgroups. The one or more processors are configured to receive a communication transmitted from a satellite constellation indicating that a first priority talkgroup has been assigned for the communication device and to receive one or more signal transmitted from the satellite constellation via a control channel indicating that the first priority talkgroup is active, in response to which the one or more processors may determine that the first priority talkgroup has been assigned for the communication device and that the first priority talkgroup is active. Consequently, the one or more processors may set the communication device to the first priority talkgroup such that the communication device starts receiving communications via the first priority talkgroup.

Abstract: A method of operating a satellite communication network is disclosed. The network includes a plurality of satellites interconnected by a plurality of satellite-to-satellite communication links. Each of the plurality of satellites is configured to communicate with at least one ground station using respective ground-satellite communication links. The method includes transmitting a routing table to each of the satellites. Each routing table has a list of destination satellites, and defines at least two possible routes leading to it. An alert message identifying a problem communication link is transmitted to a subset of the plurality of satellites. In response to receiving the alert message, subsequent data packets are routed through the communication network by the satellites using their respective routing table to avoid the problem communication link.

Abstract: In one implementation, interference generated by a constellation of satellites is mitigated. Each satellite is configured to provide multiple beams that define a coverage footprint. Anticipated positions are determined for satellites. Based on the anticipated positions, a determination is made that, during a defined period of time, portions of a coverage footprint for a first satellite will be covered by coverage footprints for other satellites. Based on this, a beam assignment for the first satellite is defined in which a first subset of beams configured to provide coverage of a first portion of the first coverage footprint are inactive, and a beam assignment for a second satellite is defined in which a second subset of beams are active, where the second subset of beams provide coverage within the first portion of the first coverage footprint.

Abstract: In one implementation, a communication device comprising one or more processors is configured to participate in a plurality of talkgroups. The one or more processors are configured to receive a communication transmitted from a satellite constellation indicating that a first priority talkgroup has been assigned for the communication device and to receive one or more signal transmitted from the satellite constellation via a control channel indicating that the first priority talkgroup is active, in response to which the one or more processors may determine that the first priority talkgroup has been assigned for the communication device and that the first priority talkgroup is active. Consequently, the one or more processors may set the communication device to the first priority talkgroup such that the communication device starts receiving communications via the first priority talkgroup.

Abstract: In one implementation, a request to initiate emergency communications is received at a wireless local area network hotspot. A number of mobile communication devices connected to the wireless local area network hotspot and location information of the wireless local area network hotspot are determined. A distress message is generated that includes the number of mobile communication devices connected to the wireless local area network hotspot and the location information. The distress message is transmitted to a contact address for an emergency contact.

Abstract: In one implementation, load balancing within a constellation of communications satellites is performed. Anticipated positions of satellites are determined. Each satellite is configured to provide multiple beams that define a coverage footprint for the satellite. Based on the anticipated positions of the satellites, it is determined that a first coverage footprint for a first satellite provides primary coverage of a high traffic region and portions of the first coverage footprint for the first satellite also will be covered by coverage footprints for other satellites, Based on these determinations, a beam assignments are defined in which a first subset of beams of the first satellite configured to provide coverage of a first portion of the first coverage footprint are inactive and a second subset of beams of the second satellite are active. The second subset of beams of the second satellite provide coverage within the first portion of the first coverage footprint.

Abstract: In one implementation, interference generated by a constellation of satellites is mitigated. Each satellite is configured to provide multiple beams that define a coverage footprint. Anticipated positions are determined for satellites. Based on the anticipated positions, a determination is made that, during a defined period of time, portions of a coverage footprint for a first satellite will be covered by coverage footprints for other satellites. Based on this, a beam assignment for the first satellite is defined in which a first subset of beams configured to provide coverage of a first portion of the first coverage footprint are inactive, and a beam assignment for a second satellite is defined in which a second subset of beams are active, where the second subset of beams provide coverage within the first portion of the first coverage footprint.

Abstract: In one implementation, a wireless communication terminal includes a sense antenna module configured to sample an interference signal. The wireless communication terminal also includes a primary antenna module configured to receive a desired signal. The sense antenna module has a first polarization type, and the primary antenna module has a second polarization type, substantially orthogonal to the first polarization type of the sense antenna module. In addition, the wireless communication terminal includes at least one signal combiner configured to receive output from the sense antenna module and output from the primary antenna module. The at least one signal combiner is configured to mitigate interference with the desired signal by shifting the phase of the output from the sense antenna module by substantially 180 degrees and combining the phase-shifted output from the sense antenna module with the output of the primary antenna module to produce an interference mitigated signal.

Abstract: In one implementation, a wireless communication terminal includes a primary antenna array and a first controller configured to steer a main beam of the primary antenna array in a desired direction. The wireless communication terminal also includes an auxiliary antenna array and a second controller configured to control complex weights to be applied by at least some antenna elements of the auxiliary antenna array to corresponding variants of a second signal received by the at least some auxiliary antenna elements. Furthermore, the wireless communication terminal includes at least one signal combiner configured to combine variants of the second signal received from auxiliary antenna elements into an interfering signal that models interference from a co-located wireless communication terminal and subtract the interfering signal from variants of the first signal received from antenna elements of the principal antenna array to produce an interference mitigated signal.

Abstract: In one implementation, a request to initiate emergency communications is received at a wireless local area network hotspot. A number of mobile communication devices connected to the wireless local area network hotspot and location information of the wireless local area network hotspot are determined. A distress message is generated that includes the number of mobile communication devices connected to the wireless local area network hotspot and the location information. The distress message is transmitted to a contact address for an emergency contact.

Abstract: A request to provide a sharecode is received from a first communication device associated with a first organization, and the sharecode is provided. Thereafter, the sharecode and a talkgroup sharing parameter are received from a second communication device associated with a second organization. The talkgroup sharing parameter identifies a talkgroup associated with the second organization to be shared with the first organization. An indication that one or more devices associated with the first organization are permitted to participate in the talkgroup associated with the second organization then is provided to the first communication device associated with the first organization.

Abstract: In one implementation, a wireless communication terminal includes a primary antenna array and a first controller configured to steer a main beam of the primary antenna array in a desired direction. The wireless communication terminal also includes an auxiliary antenna array and a second controller configured to control complex weights to be applied by at least some antenna elements of the auxiliary antenna array to corresponding variants of a second signal received by the at least some auxiliary antenna elements. Furthermore, the wireless communication terminal includes at least one signal combiner configured to combine variants of the second signal received from auxiliary antenna elements into an interfering signal that models interference from a co-located wireless communication terminal and subtract the interfering signal from variants of the first signal received from antenna elements of the principal antenna array to produce an interference mitigated signal.