The disclosure provides for the flexible assignment of user beams to gateway beams in digital payload satellite systems. A virtual beama set of data values associating a physical user satellite beam with a Gateway Earth Station (GW) and used by the GW to service the physical user satellite beam, may be created or defined each time a physical user satellite beam is assigned to a GW. For one physical user beam, a plurality of virtual beams may be created, where each virtual beam corresponds to a GW. The virtual beams may be used to provide for the flexible assignment of user beams to gateway beams in a variety of applications such as GW expansion, physical user beam reassignment from one GW to another GW, diversity operation of terminals, and GW redundancy.

Disclosed methods of terrestrial station monitoring of downlink signal quality include receiving a sequence of samples of reference symbol slots of a downlink burst, and estimating a time offset between a local clock and a timing of a symbol pattern carried by the reference symbol slots, using a local copy of the reference symbol pattern. A corresponding time correction is applied to the sequence of samples to form time corrected samples of symbols carried by the reference symbol slots. A frequency offset between the time corrected samples of the symbols carried by the reference symbol slots and a local clock is estimated. A corresponding frequency compensation is applied to the time corrected samples, forming time/frequency compensated samples of the symbols carried by the reference symbol slots. A signal to noise plus interference ratio (SNIR) estimation data, and corresponding estimate of signal path, is generated, based on moments of the time/frequency compensated samples.

A hub terminal and remote client communicate via a target satellite in an inclined geosynchronous orbit. As the target satellite ascends or descends away from the geostationary arc, the signal strength of the uplink channel is increased without increasing the level of interference with adjacent geostationary satellites. The increased angular separation from adjacent satellites also decreases downlink interference. The resulting increase in signal to interference ratio permits adjustment of the modulation and coding parameters to increase spectral efficiency. The antenna gain pattern is modeled based on antenna characteristics and the model may be supplemented with measurements of a signal relayed by adjacent satellites. The method permits intermittent communication from locations where the geostationary arc is blocked or using disadvantaged antennas that would be impractical for use with geostationary satellites. In some circumstances, it is desirable to deliberately mis-steer the antenna slightly away from the target satellite.

Satellites in the direct-to-user Earth observation (EO) satellite system support inter-satellite communication and form a multihop communication network. Each satellite has a radio transceiver with a phased array antenna for directly communicating with a user radio station that issues an EO request of a user. Physical servers are distributed over the satellites and networked to form an in-space computer network that is Internet-enabled. The multihop communication network enables the servers to be mutually communicable. Raw data generated from the EO sensors are processed by the servers to yield desired EO data that meets the user's requirement. Advantageously, the servers set up a user authentication server configured to verify the user identity for determining acceptance or denial of the EO request, and an application server for interacting with the user. Hence, the EO request is entirely handled in Space without involving a terrestrial non-user facility for user authentication and raw-data processing.

The present teachings disclose implementations of a UE and a method for providing a Narrowband Internet of Things (NB-IoT) network, the method including: receiving an NB-IoT downlink over a forward link; obtaining MAC configuration parameters, a transmit-timing offset and a transmit-frequency offset; pre-adjusting, to align with a return link timing and a return link frequency, a transmit-timing with the transmit-timing offset and a transmit-frequency with the transmit-frequency offset; requesting, based on the MAC configuration parameters and after the pre-adjusting, a connection with a Random-Access Preamble (RAR) over an NB-IoT uplink via the return link; and establishing the connection upon receiving a Random-Access Response (RAR), where a Round Trip-Time (RTT) from a transmitting antenna to a receiving antenna is greater than 67 microseconds (us), and both the NB-IoT downlink and the NB-IoT uplink use a mostly unchanged NB-IoT standard waveform. The NB-IoT service may be relayed by a satellite, for example, a geosynchronous earth orbit satellite. Further corrections to the timing and frequency may be performed on the connection. A cell or beam selection may be based on an NB-IoT system type, including NB-IoT over satellite, indicated in a Master Information Block.

A method to provide dedicated bandwidth, the method including: provisioning transmitters to transmit over a satellite link; generating, for each of the transmitters, a respective transmit signal using a common codeblock asynchronous sub-carrier multiple access (A-SCMA) encoding for a respective information stream; transmitting, via the satellite link, the respective transmit signal from each of the transmitters; and varying a bandwidth rate of each of the respective transmit signals with a grant-free protocol, where the bandwidth rate of the respective transmit signals is less than or equal to a maximum system rate, the transmitting of at least two or more of the transmitters is at least partially concurrent, and each of the respective transmit signals is modulated at a common frequency over a common frequency band with a common polarization. The method reduces latency, jitter, and provides dynamic bandwidth allocation without allocation feedback.

A method for a hitless handover in a hitless handover of communications in a Radio Frequency (RF) network is disclosed. The method including: providing a terminal comprising a first demodulator, a second demodulator and a phased array antenna; receiving communications via a first outroute signal in a first coverage area with the phased array antenna over a first outroute and processed by the first demodulator; transmitting a first inroute signal in the first coverage area with the phased array antenna over a first inroute; determining that the first outroute is setting when the terminal is imminently leaving the first coverage area and that a second outroute is rising when the terminal is entering a second coverage area; acquiring a second outroute signal in a second coverage area with the phased array antenna over the second outroute and processed by the second demodulator; sending a request to receive the communications over the second outroute, while the terminal is disposed in an overlap of the first coverage area and the second coverage area; establishing communications via the second outroute; and handing over communications from the first outroute to the second outroute while the terminal is disposed in the overlap, where the communications are received by the terminal without interruption, without a pause and without replication over the first outroute and the second outroute.

A system and method for networked geofencing includes identifying restricted areas in a service region, and defining a protective zone surrounding the restricted areas. A service availability map containing the protective zones is generated and broadcast within the service region. The positions of terminals on the service availability map are detected relative to the protective zones. Terminals inside the protective zones establish communication using a first frequency range, and terminals outside of the protective zones establish communication using either the first frequency range or a second frequency range.

Telemedicine systems and methods are described. In a telemedicine system operable to communicate with a remote operations center, communications can be transmitted/received using a transceiver having an antenna. The antenna can include first and second di-pole antenna elements, the first di-pole antenna element being vertically polarized and the second di-pole antenna element being horizontally polarized. A controller of the system can establish, using the transceiver, a telemedicine session with the operations center using a Transport Morphing Protocol (TMP), the TMP being an acknowledgement-based user datagram protocol. The controller can also mask one or more transient network degradations to increase resiliency of the telemedicine session. The telemedicine system can include a 2D and 3D carotid Doppler and transcranial Doppler and/or other diagnostic devices, and provides for real-time connectivity and communication between medical personnel in an emergency vehicle and a receiving hospital for immediate diagnosis and treatment to a patient in need.

Systems, apparatuses, methods, and software are described herein that provide enhanced satellite link-coupled communication nodes. In one example, a parent communication node includes a communication interface configured to communicate with a plurality of child communication nodes over corresponding satellite communication links. The parent communication node includes a resource manager configured to determine physical resources local to each of the plurality of child communication nodes, establish a pool of resources from among the physical resources, and responsive to a request for execution of an application, allocate resources from the pool of resources for execution of the application at one or more selected child communication nodes. The parent communication node can initiate execution of the application using the allocated resources at the one or more selected child communication nodes.