Abstract: Aspects of the invention provide a system and method to allow inroute frame timing synchronization without the aid of hub signal loopback or satellite ephemeris data. Furthermore, it allows tracking and compensating of the satellite motion to allow multiple remotes to use TDMA on the inroute frequencies, while minimizing the aperture. Two main techniques proposed are CLT and polling based approaches, which are used in combination for an optimum solution. In CLT based approach, hub transmits remote specific timing correction feedback messages on the outroute on as needed basis. In polling based approach, the remotes derive their timing based on a per-beam average delay estimate broadcast by the hub and a measured local delay specific to each outroute stream from a remote. An aspect of the invention uses triangulation method to determine satellite position. Furthermore, an aspect of the invention uses hub burst arrival method instead of polling approach.

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: A method for controlling data traffic with random early detection and window size adjustments including performing random early detection on incoming data packets, calculating a simple moving average of packet dropping probabilities for the data packets as calculated when performing random early detection, decreasing an advertised window size if the simple moving average is greater than a probability target plus a tolerance factor, increasing the advertised window size if the simple moving average is less than the probability target minus a tolerance factor, and not adjusting the window size if the simple moving average is not greater than a probability target plus a tolerance factor and not less than a probability target minus a tolerance factor.

Abstract: An approach is provided for encoding a source signal based on a structured parity check matrix of a Low Density Parity Check (LDPC) code. The LDPC code is represented by stored information reflecting a tabular format of rows and columns, wherein each row represents occurrences of one values within a respective column of the parity check matrix, and wherein the columns of the parity check matrix are derived according to an operation based on the respective rows of the stored information. Blocks of information bits of the source signal are encoded based on the LDPC code to generate an encoded signal. Row indices of 1's in a column index of the parity check matrix are given at a respective row according to the stored information. The LDPC code is of a structure that facilitates use of a plurality of parallel engines for decoding the encoded signal.

Abstract: An approach is provided for high penetration alerting in a mobile satellite system. A message is generated for transmission to a wireless terminal. The message is partitioned into a number of symbols, each symbol composed of a portion of the message. The symbols are encoded via FEC coding to generate outer coded symbols, and each outer coded symbol is encoded based on a corresponding binary orthogonal sequence. The inner coded symbols are modulated based on a binary modulation scheme, and pulse shaped to generate message bursts for transmission to the wireless terminal. Each message burst reflects a group of the inner coded symbols, wherein the grouping of the inner coded symbols facilitates joint sequence detection by the wireless terminal, and each message burst exhibits relatively low peak-to-average power ratio.

Abstract: A method for inroute bandwidth allocation supporting multiple traffic priorities in a satellite network including generating a backlog report, transmitting the backlog report to an inroute group manager, receiving a bandwidth allocation from the inroute group manager, and servicing priority queues and transmitting data to a satellite based on the bandwidth allocation from the inroute group manager.

Abstract: A multiple access scheme is described. One or more encoders are configured to encode a plurality of bit streams using Low Density Parity Check (LDPC) coding. The bit streams correspond to a respective plurality of terminals. The plurality of bit streams are converted to provide a multiple access scheme for the terminals.

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: A logarithmic (LOG) based adaptive algorithm to track RF power received at a receiver is provided. The method includes: receiving, by a variable gain amplifier (VGA) having exponential gain characteristics, an input signal; and providing log-based gain control of the input signal by determining a power of the input signal, and generating, according to the determined power, a voltage control signal using a log-based function, wherein the VGA amplifies the input signal based on the voltage control signal.

Abstract: Methods, systems and software are provided for high order signal modulation based on improved signal constellation and bit labeling designs for enhanced performance characteristics, including decreased power consumption. According to the improved signal constellation and bit labeling designs for enhanced performance characteristics, designs for 8-ary, 16-ary, 32-ary and 64-ary signal constellations are provided. According to an 8-ary constellation, improved bit labeling and bit coordinates are provided for a 1+7APSK signal constellation. According to a 16-ary constellation, improved bit labeling and bit coordinates are provided for a 6+10APSK signal constellation. According to three 32-ary constellations, improved bit labeling and bit coordinates are provided for a 16+16APSK signal constellation and two 4+12+16APSK signal constellations.

Abstract: An approach for providing flow control in a radio communication system is disclosed. A request from a non-satellite system specific side of a transport interface is made to a system specific side of the transport interface for a flow control allocation that specifies an amount of data to be stored in a queue of the system specific side of the transport interface. The system specific side supports a signaling function that is based on a transmission characteristic of the radio communication system. The flow control allocation is generated based upon availability of the queue, wherein the destination address is a link layer address of the satellite communication system. This arrangement has particular applicability to a satellite network (e.g., Very Small Aperture Terminal (VSAT) 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: The present invention provides a low density parity check (LDPC) code system and method of using such a system. A transmitted LDPC code block size may be chosen such that the minimum transmitted block size is minimized. Further, the system provides for intermediate LDPC code block size support. Finally, a common decoder architecture may be used to decode different LDPC code rates and block sizes.

Abstract: A triple use satellite system includes a VSAT population including a VSAT, and a satellite including a broadcast beam for a broadcast service and spot beams for a broadband service, where each of the spot beams provides broadband service to VSATs in separate coverage areas in a geographic region and the broadcast beam provides a broadcast service to the VSAT population in the geographic region.

Abstract: A method for traffic management and resource allocation on a shared access network including estimating a bandwidth capacity of a gateway, determining a demand rate of an IP gateway, allocating bandwidth to the IP gateway based on the demand rate, traffic priority, or traffic weighting, allocating bandwidth to the IP gateway in advance of demand when excess bandwidth is available, scheduling traffic at the IP gateway based on traffic priority, service plan of a VSAT, or physical layer properties of the VSAT, performing priority queue servicing of traffic at a gateway using a real time traffic priority queue, a non-real time traffic priority queue, two or more modulation and coding queue groups, and a code block queue.

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: A system is provided for use with a frequency band including a transmission frequency and a received frequency. The transmission frequency includes a transmission signal having a transmitted unique word therein. The received frequency includes a received signal having a received unique word therein, wherein the received unique word had been received at a received time and at a received phase. The system includes a first sub-correlator, a second sub-correlator and a discrete Fourier transform device. The first sub-correlator can perform a first correlation of only a first portion of the received unique word with a corresponding first portion of the transmitted unique word over a plurality of instances of time and can output a first plurality of sub-correlation values.

Abstract: A high capacity satellite communications system including a satellite with a beam for a forward downlink focused on a geographic area for which disproportionately higher capacity is desired, a hub located in a geographic area for which disproportionately lower capacity is desired, compared to the location of a VSAT, and the VSAT located in area where a beam for a forward downlink received by the VSAT from the satellite does not overlap with a beam for a return downlink received by the hub from a satellite.

Abstract: An approach provides a satellite air interface to efficiently support communication with a terrestrial network. One or more packets associated with a data communication session are received from a terrestrial network configured to provide cellular communications. A frame representing the packet for transmission is generated over a satellite link to a user terminal. Signaling information for the transmission of the packet over the terrestrial network is modified or eliminated for transmission over the satellite link.

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.