Abstract: A system and method for timing synchronization of satellite switching instants with gateway switching instants is described.

Abstract: A Radio Frequency Impairments (RFI) compensator and a process to remove RFI is disclosed. The RFI compensator including: a conjugator to conjugate a signal {tilde over (x)}[n] to provide a signal {tilde over (x)}*[n]; and a filter to apply coefficients that equalize a linear distortion of the signal {tilde over (x)}[n] and reject an interfering image of the signal {tilde over (x)}*[n]. The signal {tilde over (x)}[n] may be a single wideband carrier or may include multiple carriers at different carrier frequencies.

Abstract: A method for balancing inroute traffic load that contains both guaranteed QoS and best effort traffic. Hierarchical grouping levels are defined with the lowest level corresponding to inroutes within the system. Certain levels have common symbol rates, modulation rates, or both. When a new terminal requires admission, it is assigned to entries in the different hierarchical levels so that the inroute traffic load across all levels are balanced. Terminals are admitted to inroutes based, in part, on their channel quality indicator. Inroute traffic load can periodically rebalance based on elapsed time or terminal redistribution.

Abstract: A base station computer that includes a processor and memory storing instructions executable by the processor is described. The processor may be programmed to: determine a geographic position of a user terminal (UT); store the position in the memory; determine to page the UT; correlate a satellite beam based on the position; and page the UT via the satellite beam.

Abstract: A terminal device in a first network includes a processor programmed to receive first data indicating a respective first loading of each of a plurality of first level access devices. The processor is further programmed to select a first level access device based at least in part on the first data; and communicate with a second network via the selected first level access device and a selected second level access device. Each of the first level access devices is switchable to communicate with the first terminal via at least a respective one of one or more shared access channels, and each of a plurality second level access devices is switchable to communicatively couple one or more of the plurality of first level access devices with a second network.

Abstract: Interference cancellation in a receiver can be used to improve bandwidth efficiency. The transmission of bursts from different terminals scheduled at separate time intervals can overlap partially such that time used for information transmission is optimized. For example, a receiver includes a signal processor including instructions executable to select first data including a first burst and a successive second burst from a transmission. The signal processor demodulates and decodes information from the first burst. The signal processor further generates a remodulated first burst based on recoded and remodulated information and generates second data by subtracting the remodulated first burst from the first data. The signal processor synchronizes with a stored symbol pattern in the second burst; and demodulates and decodes the information from the second burst. With such arrangement, the performance of each link is not affected by the partially overlapping burst.

Abstract: A system is disclosed for providing low data rate broadcast services. Different types of broadcast packets are detected among data packets received an external network. The different types broadcast packets contain different a different broadcast content. When a particular type of broadcast packet is detected, a transmit data rate is selected and Walsh codes are assigned for achieving the transmit data rate. Data packets corresponding to the broadcast packets are compressed, and at least one RLC block containing the compressed data packets is created. The RLC blocks are transmitted from a satellite using the assigned Walsh codes.

Abstract: Systems and methods are disclosed and include a method that includes adding a training symbol prefix to an OFDM symbol frame, the prefix including a plurality of training symbols, each including N sub-symbol fields. N/2 of the sub-symbol fields are zero valued, and N/2 of the sub-symbol fields carry corresponding symbols of a N/2 sub-symbol pseudo random training symbol. A first half of the pseudo random training symbol is symmetrical to a second half of the pseudo random training symbol. An OFDM N-sub-carrier transmission carries the prefix as signal power on a first N/2 of its N sub-carriers and suppresses signal power on a second N/2 of the sub-carriers. The first N/2 and second N/2 sub-carriers alternate in the frequency domain.

Abstract: A system and a method for directing a handover of communications in Radio Frequency (RF) networks at a UT. The method includes servicing a user terminal (UT) via a first network having a first coverage area; receiving, from the UT via the first network, a measurement report for a second network having a second coverage area based on a measurement configuration of the second network; sending, to the UT via the first network, a handover order for obtaining service from the second network; and establishing, via a second network RAN (radio access network), a service for the UT via the second network per the handover order. In the method, the first network may include either a terrestrial network (TN) or a non-terrestrial network (NTN), the second network may include other of the TN or the NTN, and the TN and the NTN are RF networks.

Abstract: A system to provide second generation (2G) voice services over internet protocol, the system including: a voice gateway (VGW) including a 2G stack to communicate control plane information and user plane information with a 2G user terminal (UT) via a circuit-switched network without modifications to the 2G-UT, an Iu-CS IP stack, and a relay to map the control plane information between the 2G stack and the Iu-CS IP stack, and vice-versa; a mobile switching center (MSC), connected to the VGW via the Iu-CS IP stack, to manage and establish the voice services between the 2G-UT and a public switched telephone network (PSTN) based on the mapped control plane information; and a media gateway (MGW) connected to the VGW via the Iu-CS IP stack, where the MGW communicates the user plane information between the 2G-UT and the PSTN after the MSC 2-G UT vocoder, e.g. AMBE, has established voice services.

Abstract: Techniques for data transmission include a geostationary earth orbiting satellite that includes a first optical communication system configured to receive forward-direction user data via a forward optical link between the satellite and a stratospheric high-altitude communication device, and a first radio frequency (RF) communication system configured to transmit, via a plurality of RF spot beams, the forward-direction user data. The stratospheric high-altitude communication device includes a second RF communication system configured to receive the forward-direction user data via a plurality of concurrent forward RF feeder links, and a second optical communication system configured to transmit to the satellite, via the forward optical link, the forward-direction user data received via the plurality of forward RF feeder links.

Abstract: A system includes a shield for a low noise amplifier. The shield includes a top and one or more walls extending from the top defining a cavity. The shield further comprises at least one conducting member extending outwardly from the top and within the cavity. The shield may enclose an amplifier circuit and improve its signal-to-noise ratio.

Abstract: Application layer throughput (ALT) shaping is provided for a streaming media session is provided. A request for a content segment is received. The receipt time of the request is recorded and the request is forwarded to a content server. A response message is received from the server. The receipt time of the response and a segment size is determined. An ALT for the current segment is determined based on the receipt times of the request and response messages and the segment size. The ALT rate is compared to a target ALT rate required for a desired session PBR. When the ALT rate is higher than the target ALT rate, the content response is held for a time period determined to lower the current ALT rate to the target ALT rate, and then released to the client device. Otherwise, the content response is promptly provided to the client device.

Abstract: A phase shifter having both digital and analog shifting components is disclosed. The digital-analog phase shifter includes an input/output port configured, in part, for receiving an input radio frequency (RF) signal from an external source and outputting a phase shifted RF signal. A digital shifter performs coarse phase shifts of the input RF signal, while an analog shifter variably shift the phase of the input RF signal relative to the coarse phase shift. This produces a phase shifted RF signal having a total phase range that is output is continuously variable from 0° to 360°.

Abstract: A satellite communication system includes a communication terminal, and a ground station. The ground station is configured to communicate with the communication terminal through a satellite communication path between the ground station and the communication terminal via a satellite. The ground station includes a diversity switch, and an electronic controller. The diversity switch is configured to switch the satellite communication path from a first satellite communication path to a second satellite communication path different from the first satellite communication path. The electronic controller is configured to determine whether a predetermined switching condition is satisfied based on signal attenuations of the first and second satellite communication paths. The electronic controller is further configured to control the diversity switch to switch the satellite communication path upon elapsing a first predetermined time period after determining that the predetermined switching condition is satisfied.

Abstract: Various arrangements are presented for optimizing data transmission between a satellite and a user equipment. A satellite gateway system may receive a message from the user equipment indicative of a current location of the user equipment. Data may be retrieved from the Internet to be transmitted to the user equipment via the satellite. The satellite gateway system may transmit a downlink message to the satellite that comprises the retrieved data and beam steering data. The beam steering data may instruct the satellite to target a downlink spot beam on the current location of the user equipment based on the message received from the user equipment. The retrieved data may be transmitted to the user equipment via the targeted downlink spot beam.

Abstract: Methods and apparatus for increasing spectral efficiency in non-orthogonal multiple access (NOMA) communication, that implement receiving a signal stream from a user, splitting the signal stream into a plurality of sub-streams, applying a forward error coding (FEC) to each one of the sub-streams, and outputting a corresponding plurality of FEC encoded sub-streams. This can include modulating a corresponding carrier with each of the FEC encoded sub-streams, and combining and transmitting the corresponding plurality of modulated carrier signals. The modulated carrier signals can each carry a respective one of the FEC encoded sub-streams.

Abstract: Systems and methods are provided for channelizing. A first stage can provide a WOLA filter bank that can apply a single multiplier resource to perform window weighting for multiple WOLA filter banks. The first stage can remove mixer-based post FFT adjustment and provide equal functionality with a particular modification of tuning mixers at inputs of second stage FIR paths. The first stage can include a variable decimation, using a particular implementation of variable sample block size.

Abstract: A satellite user terminal gateway which performs transmission control protocol acceleration to enhance communication speed between a satellite user terminal and a satellite communication network. The satellite user terminal gateway includes a transceiver configured to communicate with a satellite communication network to receive data packets from the satellite communication network, and a controller configured to control the transceiver. The satellite user terminal gateway further includes a processor configured to identify transmission control protocol data packets among the received data packets to mirror the transmission control protocol data packets to the controller while routing the received data packets through the satellite user terminal gateway.

Abstract: A method and system for providing GTP acceleration for secure cellular backhaul over satellite (CBoS). A satellite terminal receives request from a first entity to establish a security association with a second entity, and establishes a first secure tunnel to a gateway. A second secure tunnel is then established between the gateway and the second entity based on a certificate belonging to the first entity. A third secure tunnel is established between the satellite terminal and the first entity based on a certificate belonging to the second entity. The contents of encrypted traffic between the first entity and the second entity are examined so that GTP acceleration may be applied to eligible traffic transmitted over the first secure tunnel.