Abstract: Modulation and coding schemes are provided for improved performance of wireless communications systems to support services and applications for terminals with operational requirements at relatively low ES/N0 ratios. The provided modulation and coding schemes will support current and future communications services and applications for terminals with operational requirements at relatively low ES/N0 ratios, and will provide modulation and coding schemes that offer finer granularity within an intermediate operational range of ES/N0 ratios. The new modulation and coding schemes provide new BCH codes, and low density parity check (LDPC) codes.

Abstract: A satellite terminal and a machine-implemented method are provided for encoding a burst header of a burst for transmission on an inroute. One component of a group of satellite terminal components consisting of an ASIC, a FPGA, and a DSP, generates a burst header having five information bits encoded therein. The five information bits may be encoded using a Reed-Muller code, a (32, 5) block code or a convolutional code having a code rate of either 1/5 or 1/10. The five information bits may represent one or more of a modulation type for a payload of the burst, a code rate for encoding the payload, a code type, and a spreading factor for spreading the payload during transmission. A satellite gateway and a machine-implemented method are also provided for decoding a burst header of a burst received on an inroute as described above.

Abstract: Systems and methods provide bandwidth management on the inroute of a satellite network. Inroute group managers (IGMs) monitor bandwidth usage in each terminal group (TG) under each of the IGMs, and report this bandwidth usage to a bandwidth manager. Upon receipt of the reported bandwidth usage from each of the IGMs, the bandwidth manager compares the bandwidth usage and minimum/maximum throughput rates associated with each TG. The bandwidth manager calculates scaling factors that it transmits to each of the IGMs to allow the IGMs to allocate bandwidth accordingly.

Abstract: Systems and methods are provided to achieve dynamic bandwidth allocation among terminal groups (TGs) with proportional fairness in terms of both throughput and spectrum usage across a network. Quality of service (QoS) metrics for such TGs can be satisfied in terms of maximum throughput and spectrum utilization, while also satisfying QoS metrics such as latency, throughput, and prioritized traffic services for individual terminals within the TGs. A centralized bandwidth manager can be utilized to manage such dynamic bandwidth allocation across multiple Code Rate Organizers (CROs), including environments in which the multiple CROs manage communications across multiple IPGWs for multiple terminal groups. Because, in such environments, a given conventional CRO cannot effectively manage allocations across the entire network, the centralized bandwidth management functionality can be introduced to assess the flows for multiple TGs across multiple CROs and to make bandwidth allocations accordingly.

Abstract: A system for a multiplexing scheme for wideband signals in a communications system is provided. A codeblock of a multiplexed datastream is decoded. The codeblock includes a flag indicating whether the codeblock contains a timeplan, signifying a multiplexing structure of the datastream. A determination is made whether the flag indicates the presence of the timeplan, and, if so, the timeplan is acquired. In response to a determination that the codeblock does not contain the timeplan, a subsequent codeblock is determined, and decoded. Each codeblock includes an indicator of a sequence position of the codeblock within a group of codeblocks of the datastream. The subsequent codeblock is determined based on one or more of a decode rate of the processor device and the sequence position indicator. A determination is made whether the flag of the subsequent codeblock indicates the presence of the timeplan, and, if so, the timeplan is acquired.

Abstract: An uplink power control system and a machine-implemented method for determining clear sky and adjusting uplink power are provided. A receiving station, which may be a satellite terminal or a satellite gateway, receives a reference signal from a satellite. The reference signal may be sampled over a sampling time period in order to compute a filtered short-term average downlink SINR. A filtered long-term average downlink SINR may be adjusted toward the filtered short-term average downlink SINR using either a first time constant or second time constant, based on a relationship between the filtered long-term average downlink SINR and the filtered short-term average downlink SINR. In some implementations, the second time constant is less than the first time constant.

Abstract: Modulation and coding schemes are provided for improved performance of wireless communications systems to support services and applications for terminals with operational requirements at relatively low Es/N0 ratios. The new modulation and coding schemes provide new BCH codes, low density parity check (LDPC) codes and interleaving methods.

Abstract: An approach is provided for increasing transmission throughput rates for a source signal transmitted over a wireless channel, applying faster-than-Nyquist (FTN) signaling rates combined with tight frequency roll-off to the a source signal. A receiver is provided that compensates for ISI effects induced by the FTN rate and tight frequency roll-off, where the complexity of the receiver grows only linearly with the interference memory. The receiver comprises an equalizer configured to compensate for the ISI effects, and a decoder configured to decode the output of the equalizer to determine and regenerate the source signal. The receiver processes the received signal via a plurality of processing iterations. For one processing iteration, the decoder generates a set of a posteriori soft information based on the output of the equalizer, and the equalizer uses the a posteriori soft information as a priori soft information for a subsequent processing iteration.

Abstract: An apparatus, method, and system for quality of service over dedicated local loop networks is provided. Information regarding uplink and downlink speeds, and information regarding WAN interface protocol and encapsulation mode, is received from a network device. A link throughput limit is calculated based on the uplink speed of the network device, and a link throughput limit is set based on the calculated uplink throughput limit. An uplink network protocol overhead of the network device is calculated based on the WAN interface protocol and encapsulation mode of the uplink device and is factored in upstream available bandwidth calculations. Communication data size(s) are set based on the calculated uplink network protocol overhead. The downlink throughput limit is set to match the downlink speed based on the downlink speed and WAN network protocol overhead. The WAN network protocol overhead is factored in the downstream available bandwidth calculations and communication data sizes.

Abstract: An approach for allocating bandwidth is disclosed. A request is detected from a terminal for capacity on a communication channel based on type of traffic transmitted from the terminal. A bandwidth allocation pattern designated for the terminal is retrieved, wherein the bandwidth allocation pattern is set based on a predetermined service plan associated with the terminal. Bandwidth over the communication channel is reserved for the terminal according to the bandwidth allocation pattern without feedback to the terminal. This arrangement has particular applicability to a satellite network that provides data communication services.

Abstract: Systems and methods for performing preprocessing of received data packets, to reduce processing burdens and improve efficiency of communications terminal receivers, are provided. A first stage filter receives a data frame comprising data packets representing respective encapsulated fragments of a PDU. The first stage filter parses a header of one of the packets to locate a start field, and determines whether the start field indicates that the packet comprises a start fragment of the PDU. When the start field indicates that the packet comprises the start fragment, the first stage filter determines, based on packet label information of the packet header, whether to forward the packet to a second stage filter or to discard the packet, and forwards or discards the packet accordingly. When the start field indicates that the packet does not comprise the start fragment, the first stage filter forwards the packet to the second stage filter.

Abstract: A numerically controlled oscillator includes a phase accumulator configured to output a phase word, a clock configured to periodically output a clock signal in accordance with a delay interval, and a clock controller configured to adjust the delay interval. The phase accumulator is configured to output a new phase word in response to receiving the clock signal. An example 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, and converting the phase word to a waveform.

Abstract: A signal transmission approach comprises encoding a source signal (comprising a plurality of source symbols) to generate a corresponding encoded signal. The encoded signal is modulated by mapping each source symbol to a respective signal constellation point of an applied signal constellation to generate a modulated signal. The modulated signal is pre-distorted based on a distortion estimate to generate a pre-distorted signal. The pre-distorted signal is filtered to generate a filtered signal. The filtered signal is frequency translated and amplified to generate a transmission signal for transmission via an uplink channel of a satellite communications system. To increase throughput, the source signal is processed through the apparatus and the resulting transmission signal is generated at a Faster-than-Nyquist (FTN) symbol rate and with a tight frequency roll-off.

Abstract: An approach for transmission of data packets, based on virtual frame timing, over a communications channel is provided. A remote terminal receives a first stream of data packets at periodic time intervals. The terminal receives an allocation of time slots within a sequence of TDMA transmission frames, for transmission of the data packets over the channel. The timing structure of the allocated time slots is based on a virtual frame size relative to the interval timing of the first data packet stream, and independent of the frame size/timing of the TDMA transmission frames. The remote terminal may receive a second stream of data packets at periodic time intervals that differ from the time intervals of the first stream. In a multi-stream scenario, the virtual frame size for the time slot allocation is based on the greatest common denominator of the interval timings of the first and second data streams.

Abstract: A system and method is provided to enable enhanced paging for 3GPP IMS based Mobile Satellite Communication is presented. The method is achieved by utilizing the network requested secondary PDP context activation (NRSPCA) features of 3GPP release 7. NRSPCA involves interaction between P-CSCF, GGSN, and SGSN that eventually allows SGSN to identify the traffic type of the incoming call without looking at the compressed SIP messages. RAN can do enhanced paging, if necessary; based on the request secondary PDP context activation message, if the Paging Cause is indicating conversational class. In another embodiment, enhanced paging can be achieved by marking the packet with an appropriate DSCP code, which is done by the P-CSCF. SGSN can populate the paging cause with enhanced paging code based on the DSCP code provided or RAN can escalate paging to enhanced paging by examining the DSCP code.

Abstract: Approaches are provided for closing communications channel links (e.g., for small terminal applications in satellite communications systems), at lower effective data rates, in a most power efficient manner, while still meeting regulatory requirements. Such approaches employ modulation and coding schemes that facilitate such lower effective data rates in a most power efficient manner. The new modulation and coding schemes include new low density parity check (LDPC) codes.

Abstract: A system and methods that accommodate for nonlinear interference in a multi-carrier communications system are provided. A first signal is received by a receiver. The first signal comprises a source signal transmitted on a carrier over a communications channel. The first signal reflects a source symbol mapped to one of a plurality of signal constellation points, and each signal constellation point is associated with a different one of a plurality of signal clusters. A received representation of the source signal with respect to the source symbol is acquired from the first signal. A plurality of likelihood metrics are determined, where each likelihood metric is based on the received representation of the source signal with respect to the source symbol and a different one of a plurality of core parameters, wherein each core parameter is based on a centroid estimate with respect to a different one of the signal clusters.

Abstract: Systems and methods for peer group diagnosis detection are disclosed. In an example embodiment, a beam profile including a plurality of satellite beam characteristics is determined. A peer group of satellite terminals is determined. Terminal profiles with terminal characteristics for the satellite terminals in the peer group are determined. A normalized baseline profile including normalized terminal characteristics for the peer group is determined. Measured operational statistics of the satellite terminals in the peer group are received and converted into normalized operation statistics using the terminal profiles and the normalized baseline profile. Normalized peer group operational statistics including a mean and a standard deviation of normalized operational statistics are determined. A normalized deviation of the normalized operational statistics is determined for each satellite terminal. The normalized deviations for each satellite terminal are compared to a threshold deviation.

Abstract: A dynamic and flexible architecture and methods for demodulation of high data-rate streams with high symbol-rates, such as in satellite communications systems or computer network communications systems, is provided. A data stream of a data transmission is received, the data stream corresponding to a plurality of data symbols. A plurality of data samples corresponding to each of the data symbols is generated. Further, one or more representative data samples, corresponding each of the data symbols, are generated based at least in part on timing control signals and the generated data samples for the respective data symbol. The generated data samples corresponding to each of the data symbols other than the representative data samples are dropped. The timing control signals are then adjusted based at least in part on the generated representative data samples.

Abstract: A method of providing a high symbol rate communication system with reduced overhead bandwidth includes calculating a minimum feasible aperture length at a network operations center, setting a hub demodulator subsystem to use an aperture length calculated from the minimum feasible aperture length, broadcasting the aperture length to a VSAT, and receiving an inroute data stream from the VSAT utilizing the aperture length.