Abstract: A mobile terminal for satellite communications receives communication, e.g., from a gateway via a satellite link. A frequency lock loop unit locks to the carrier frequency of the received communication. The mobile terminal includes a global positioning system for receiving global positioning data. The mobile terminal determines the Doppler frequency shift of the received communications based on the global positioning data. The mobile terminal generates a reference clock for return transmissions based on the frequency of the frequency lock loop, corrected for the Doppler shift. A correction factor of two times the determined Doppler frequency shift is used, to compensate for both a forward and return transmission link.

Abstract: A system is provided for reducing latency data collection from space-based sensor satellites. A mobile vehicle platform includes a sensor module configured to monitor certain conditions, circumstances, environments and situations occurring on or around, or associated with, the Earth, and to generate sensor data resulting from the monitoring. A relay satellite terminal is configured to execute data communications via a communications channel of a first satellite beam, wherein the data communications are configured to relay the sensor data, via satellites, to respective gateways for forwarding to a central processing facility for one or more of aggregation, processing, analysis and dissemination of the data. The relay satellite terminal is further configured to switch the data communications from the communications channel of the first satellite beam to a communications channel of a second satellite beam based on a position of the relay satellite terminal relative to the first and second satellite beams.

Abstract: A method and a satellite terminal are provided. The satellite terminal may range over multiple frequencies and may receive, from a satellite gateway, a signal quality indicator with respect to each of the ranged multiple frequencies. Noise and interference for a corresponding frequency are estimated based on at least one of the received signal quality indicators for the corresponding frequency. Path loss is estimated based on multiple received signal quality indicators, each of which is received in response to the satellite terminal transmitting a signal while not performing the ranging process. A transmit power level of the satellite terminal is adjusted for the corresponding frequency based on the estimated path loss and the estimated noise and interference for the corresponding frequency.

Abstract: A multiple access scheme is described. A first bit stream is scrambled from a first terminal according to a first scrambling signature. A second bit stream is scrambled from a second terminal according to a second scrambling signature, wherein the first bit stream and the second bit stream are encoded using a low rate code. The first scrambling signature and the second scrambling signature are assigned, respectively, to the first terminal and the second terminal to provide a multiple access scheme.

Abstract: A numerically controlled oscillator includes a phase accumulator that outputs a phase word and a clock that periodically outputs a clock signal in accordance with a delay interval. The phase accumulator outputs a new phase word in response to receiving the clock signal. A clock controller calculates a timing drift and adjusts the delay interval to reduce the timing drift. A method includes receiving a plurality of frequency control words, calculating a delay interval, accumulating the frequency control words in accordance with the delay interval to generate a phase word, converting the phase word to a waveform, calculating a timing drift, and adjusting the delay interval to reduce the timing drift.

Abstract: A multiple access scheme is described. A first bit stream is scrambled from a first terminal according to a first scrambling signature. A second bit stream is scrambled from a second terminal according to a second scrambling signature, wherein the first bit stream and the second bit stream are encoded using a low rate code. The first scrambling signature and the second scrambling signature are assigned, respectively, to the first terminal and the second terminal to provide a multiple access scheme.

Abstract: A very small aperture terminal (VSAT) installation tool is provided having the ability to measure cable loss along an interfacility link (IFL) between an outdoor unit and an indoor unit of the VSAT. Radio frequency (RF) signals can be transmitted from the indoor unit to the outdoor unit, where the RF signals are intercepted along the IFL prior to reaching the outdoor unit, and the output power is determined. The determined output power is compared to an expected output power at the indoor unit. The delta between the determined output power and the expected output power can be used to adjust the power of the indoor unit such that the outdoor unit can operate without reaching its compression point.

Abstract: Systems and methods for real-time signal validation are disclosed. In an example embodiment, a subset of terminals in a peer group of satellite terminals is determined. Operational statistics of the satellite terminals in the subset of terminals is measured. Operational statistics of each of the satellite terminals in the subset of terminals is compared to a prior measurement of the same operational statistics. An offset between a current measurement of the operational statistics and the prior measurement of the same operational statistics is determined. An average offset of the current measurement of the operational statistics and the prior measurement of the same operational statistics is determined for the subset of terminals. The average offset for the subset of terminals is merged with a previously determined peer group operational statistic. A signal validation of a terminal is performed using an updated deviation value.

Abstract: A communication system, an apparatus and a method for communicating with a radio disposed in an outdoor unit are provided. The apparatus including: a de-multiplexor configured to separate a multiplexed signal received on an inter-facility link (IFL) into a first signal; a demodulator configured to demodulate the first signal based-on a first modulator control information to obtain data; a modulator configured to modulate a portion of the data based-on a second modulator control information to generate a second signal; and an amplifier configured to amplify a transmission signal prior to transmission of the transmission signal with an antenna, wherein the transmission signal is based on the second signal, the second modulator control information is received by the de-multiplexor and the second modulator control information controls the modulation scheme used by the modulator.

Abstract: A monitoring tool to facilitate real-time system performance monitoring, fault detection, fault isolation, and fault remediation verification, wherein the monitoring tool is connected to each of a plurality of gateways within a network, including a request reporter module configured to record results of URL access requests from one or more end users, a processing module configured to calculate a set of metrics based on success and failure rates for each of the URL access requests recorded by the request reporter and distinguish between failures related to the network and failures unrelated to the network, and a consolidator module configured to organize and present the set of metrics into a format useable for monitoring the network.

Abstract: A very small aperture terminal (VSAT) installation tool is provided having the ability to measure cable loss along an interfacility link (IFL) between an outdoor unit and an indoor unit of the VSAT. Radio frequency (RF) signals can be transmitted from the indoor unit to the outdoor unit, where the RF signals are intercepted along the IFL prior to reaching the outdoor unit, and the output power is determined. The determined output power is compared to an expected output power at the indoor unit. The delta between the determined output power and the expected output power can be used to adjust the power of the indoor unit such that the outdoor unit can operate without reaching its compression point.

Abstract: Multibeam coverage for a high altitude platform is disclosed. An example apparatus includes a plurality of antennas configured to provide communication coverage among a plurality of terminals within a specified area on the ground, each antenna being configured to communicate with a specified cell within the specified area. The antennas of the example apparatus have differently sized apertures to maintain a similar surface spectral density among the cells within the specified area.

Abstract: A resource efficient approach for push-to-talk (PTT) services over a mobile communications network is provided. A remote terminal (UT) receives a command for initiating a PTT session. The UT generates a RAB binding create message, including a PTT session identifier and RAB binding information, and transmits the RAB binding create message to a wireless gateway. The UT receives a RAB binding response from the wireless gateway, and performs a protocol signaling process for establishing PDP bearers, and for establishing the PTT session on a PTT server. The UT receives a command for initiation of media transmission for the PTT session, generates talk burst (TB) request message, and transmits the request message to the wireless gateway (the TB request message is transmitted via media access control (MAC) layer control messaging). In response, the UT receives a talk burst grant message from the wireless gateway.

Abstract: Approaches for satellite data transmissions are provided, which accommodate for periodic signal blockages without packet loss. A data stream is segmented into packets for wireless transmission, wherein the transmission is subject to a periodic blockage, wherein the periodic blockage comprises two blockages occurring within a time period, and each blockage is of a respective duration and recurs at regular intervals based on the time period. A forward error correction outer code is applied to the packets for recovery of data erasures due to the periodic blockage, wherein the application of the outer code comprises applying an error correction code to each of the packets to generate a respective codeblock. Each codeblock is interleaved to prevent erasure of consecutive parity bits within the codeblock. The encoded and interleaved codeblocks are transmitted over a wireless channel, wherein a number of data erasures occur within each codeblock due to the periodic blockage.

Abstract: A TCP/IP packet decoder fetches, from a packet received via a satellite communication system, IP version information, which is provided to version comparators. When a version comparator indicates a match, protocol information is provided to a TCP comparator. If the TCP comparator determines that the packet is a TCP data packet, a flag is raised causing generation of a TCP acknowledgment for transmission to a source device. In another embodiment, a layer 3 switch or router includes a TCP hardware filter to determine whether the received packet is a TCP data packet, thereby causing the TCP data packet to be mirrored for transmission to a modem. In a third embodiment, a TCP hardware filter, provides an indication to a layer 2 switch when a TCP data packet is received causing the TCP data packet to be mirrored for transmission to a modem, which generates and transmits a TCP acknowledgment.

Abstract: A linear radio and a method for performing automatic level control are provided. A demultiplexer, within the linear radio, receives multiplexed signals from an indoor unit via a cable connecting the indoor unit with the linear radio. The demultiplexer demultiplexes the multiplexed signals to produce a transmit signal of an intermediate frequency. A variable gain amplifier within the linear radio, receives the transmit signal and a signal from an operational amplifier and produces the transmit signal with a changed gain, which is provided to a coupler. The coupler provides the transmit signal with the changed gain to a mixer and a power detector simultaneously. The power detector produces a second signal, which is provided to the operational amplifier, thereby forming a closed automatic level control loop. In some embodiments, the demultiplexer produces a power control signal, which is provided to the operational amplifier as a second input.

Abstract: A broadband satellite communications system comprises forward error correction (FEC) encoder/decoder, interleaver/deinterleaver, puncturing/de-puncturing, scrambler/descrambler, bit to symbol mapping/de-mapping devices, modulator/demodulator, transmit and receive filter; operating in a time-division multiple access (TDMA) system where information is sent in a burst-by-burst fashion during the assigned time slot; supporting diverse traffic types such as voice over internet protocol (VOIP), control messages (DACCH) and keep alive burst (KAB) during silence period and multiple data rates.

Abstract: An approach for encoding a physical layer (PL) header of a PL data frame is provided. The PL header comprises sixteen information bits ui, (i=0, 1, 2, . . . , 15), and the encoding is based on a convolutional code, whereby, for each information bit, five associated parity bits pi,k, (k=0, 1, 2, 3, 4) are generated, resulting in 80 codebits. The resulting 80 codebits are punctured to form a (16,77) codeword (c0, c1, c2, . . . , c76). The codebits of the (16,77) codeword are repeated to generate a (16,154) physical layer signaling codeword (c0, c0, c1, c1, c2, c2, . . . , c76, c76) for transmission of the PL data frame over a channel of a communications network.

Abstract: Systems and methods are provided for satellite noise and interference calibration using satellite terminal measurements. In one implementation, a method includes partitioning a satellite network into a first partition including a plurality of terminals and a plurality of inroute frequency channels (IFCs); instructing the plurality of terminals of the partition to measure the SINR of the plurality of IFCs; processing the plurality of SINR measurements to compute normalized IFC measurements for each of the plurality of terminals; processing the normalized IFC measurements for each terminal to compute final calibrated IFC SINR offsets for each IFC of the partition; and normalizing the final calibrated IFC SINR offsets with respect to a lowest SINR offset IFC. The normalized final calibration offsets may be made available to each of the satellite terminals. During subsequent operation, the satellite terminals may consider the amount of interference present in an IFC before switching to the channel.

Abstract: Systems and methods are provided for automatically re-ranging a satellite terminal. A satellite system may comprise a satellite comprising an inroute channel and an outroute channel, and a terminal configured to receive an outroute signal from the satellite on the outroute channel and transmit an inroute signal to the satellite on the inroute channel. The satellite terminal may automatically determine when to perform ranging by monitoring the quality of the outroute signal; monitoring the quality of the inroute signal; and determining if there has been a sustained degradation in the monitored inroute signal quality or the monitored outroute signal quality.