Abstract: An approach is provided for supporting retrieval of a web page over a data network from a web site is disclosed. A downstream proxy communicating with a host executing a browser receives a request message from a browser to retrieve the web page. An upstream proxy parses the web page to determine an object embedded in the web page, wherein a promise list is generated specifying the embedded object that is to be pre-fetched according to a criterion. The promise list is transmitted to the downstream proxy, wherein the upstream proxy pre-fetches the embedded object from the web site. The upstream proxy determines whether to forward one of the pre-fetched embedded object to the downstream proxy based on a comparison of cookies associated with one of the pre-fetched objects supplied, respectively, by the browser and the web site. This approach as particular applicability in relatively high latency networks, such as a satellite communications system.

Abstract: An approach for routing over a radio network is provided. A terminal receives a packet over the radio network, which supports meshed connectivity, wherein the packet is destined for a destination host. The terminal determines whether the destination host is reachable by a communication interface based upon a route table, and selectively redirects the packet over the radio network according to the route table. A route server is provided to collect routes from the terminal as well as other terminals within the radio network. The route server then disseminates the collect routes to the terminals for updating of their respective route tables. The present invention has particular applicability to a fully meshed satellite network.

Abstract: A system for transmitting data packets over an air interface includes a logic device and a transmitter. The logic device receives data packets from a user device and encodes the data packets using a turbo coding scheme. The logic device may then modulate the turbo coded data and forward the modulated data to a transmitter. The transmitter may then transmit the modulated data to a satellite over the air interface.

Abstract: A method for selecting a transmission rate and coding scheme for transmitting data packets from a remote terminal to a hub includes performing a ranging process between the hub and remote terminal. The ranging process may be repeated for each of a number of different transmission rates and coding schemes. The remote terminal may then select the appropriate transmission rate and coding scheme based on the ranging.

Abstract: An approach is provided for bit labeling of a signal constellation. A transmitter generates encoded signals using, according to one embodiment, a structured parity check matrix of a Low Density Parity Check (LDPC) code. The transmitter includes an encoder for transforming an input message into a codeword represented by a plurality of set of bits. The transmitter includes logic for mapping non-sequentially (e.g., interleaving) one set of bits into a higher order constellation (Quadrature Phase Shift Keying (QPSK), 8-PSK, 16-APSK (Amplitude Phase Shift Keying), 32-APSK, etc.), wherein a symbol of the higher order constellation corresponding to the one set of bits is output based on the mapping.

Abstract: An approach for reliably communicating over a satellite in support of a communication service including, for example, as direct broadcast satellite and data service, is disclosed. An input message is encoded, yielding a structured Low Density Parity Check (LDPC) coded message. The coded message is modulated according to a high order modulation scheme that has a signal constellation representing more than two symbols per signaling point—e.g., 8-PSK (Phase Shift Keying) and 16-QAM (Quadrature Amplitude Modulation). The system includes a transmitter configured to propagate the modulated signal over the satellite. The above approach is particularly applicable to bandwidth constrained communication systems requiring high data rates.

Abstract: An approach for generating a structured Low Density Parity Check (LDPC) codes is provided. Structure of the LDPC codes is provided by restricting a certain part of the parity check matrix to be lower triangular, hence enabling a very simple encoding method that does not require the generator matrix of the code. The approach can also exploit the unequal error protecting capability of LDPC codes on transmitted bits to provide extra error protection to more vulnerable bits of high order modulation constellations (such as 8-PSK (Phase Shift Keying)). Additionally, an efficient decoding scheme is described where both bit nodes and check nodes are partitioned into groups. The edge values associated with each of the group can be placed together in memory simultaneously for bit nodes groups and check nodes groups. This architecture allows the multiple edges to be fetched from memory at a single clock cycle.

Abstract: An approach for enhancing performance of an access network (e.g., a satellite network) in a secure environment (e.g., Virtual Private Network (VPN)) is disclosed. A plurality of connections is established with respective peer nodes over the network. Each of the peers is configured to provide performance enhancing functions for the network via the connections. The approach enables selection of one of the connections, such that the selected connection includes a secure tunnel to the peer associated with the selected connection.

Abstract: An approach for supporting security in a communications network is disclosed. A network device includes a security peer that establishes a secure tunnel over a data network (e.g., satellite network) for transport of encrypted traffic. The device also includes a performance peer for establishing a connection supported by the secure tunnel. The performance peer includes a plurality of modules for providing respective performance enhancing functions to minimize performance impact of latency of the network.

Abstract: An approach for adaptively providing network performance enhancing functions in a secure environment, such as a virtual private network, is disclosed. Traffic, for example, Internet Protocol (IP) packets, is received for transport over an access network (e.g., satellite network). Next, characteristics (e.g., latency) of the access network are determined. A connection (which supports the performance enhancing functions) is selectively established based on the determined characteristics for transport the received packets over the access network. An encrypted tunnel is provided over the established connection to transmit the received packets.

Abstract: An approach for providing integrated firewall and network acceleration functions is disclosed. An integrated firewall and network accelerator filters packets received from a host, according to a security policy, to establish a connection for accelerating the filtered packets over a network (e.g., satellite network). The method further includes selectively triggering establishment of a tunnel (e.g., Virtual Private Network (VPN) tunnel) over the established connection, wherein the filtered packets are encrypted through the tunnel.

Abstract: An apparatus for providing automatic gain control for use in a satellite terminal of a satellite communication system capable of transmitting a plurality of different modes of data. The apparatus includes a demodulator circuit having an analog to digital converter; a first variable attenuator having an attenuation value set on the basis of a measured power level of a predetermined data signal; and a second variable attenuator having an attenuation value set on the basis of the mode of data being received by the satellite terminal, where each of the data modes have a corresponding predetermined attenuation value associated therewith which is utilized as the attenuation value of the second variable attenuator when the satellite terminal receives the data mode.

Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that outputs a message signal. The transmitter also includes an encoder that generates a code word in response to the message signal. The code word has a construction that defines a plurality of paths associated with an intersymbol interference (ISI) environment of the communication channel, wherein the code word achieves a diversity based upon the number of transmit antennas and the number of ISI paths. Further, the transmitter includes a modulator that modulates the code word for transmission over the communication channel, and multiple antennas that transmit the modulated code word over the communication channel. The system encompasses a receiver that receives the transmitted code word via a number of receive antennas.

Abstract: A demodulator for use in a satellite communication system, which is operative for receiving a modulated signal having a data rate R (i.e., the demodulator receives R input samples per second). The demodulator includes a demultiplexer circuit having N shift registers, which functions to receive the R data samples per second as an input signal. The demultiplexer circuit operates to input the R input samples sequentially into the N shift registers such that each of the shift registers receives input samples at a data rate of R/N samples per second. The demodulator further includes signal recovery circuitry for processing the input samples contained in each of the N shift registers so as to regenerate the data contained in the incoming modulated signal transmitted by the satellite.

Abstract: A communication system for transmitting encoded signals over a communication channel is disclosed. The system includes a transmitter, which has a source that is configured to output a message signal, and an encoder that is configured to generate a code word in response to the message signal. The code word has a construction that is based upon a single dimensional binary code and that specifies a space-time overlay having a predetermined constraint. The transmitter also includes a modulator that is configured to modulate the code word for transmission over the communication channel. Further, the transmitter includes multiple transmit antennas that are configured to transmit the modulated code word over the communication channel. The system also includes a receiver, which may include multiple receive antennas. The receiver is configured to receive the transmitted code word via the multiple receive antennas.

Abstract: A silicon-based radiation-hard cryo-CMOS CCD process suitable for fabrication of devices (100) with sub-micron feature sizes. A re-oxidized nitride/oxide (RONO) layer (49″) is preserved in the CCD area (32) while plasma etching is used to define polysilicon 1 gates (50′) in the active FET area of the device. Thereafter, a wet chemical etching process, which does not destroy the integrity of the RONO layer (49″) in the CCD area, is carried out. A channel stop (48) is formed after the field oxidation step in the active FET area to reduce the space required for minimum diode breakdown voltage between the n+ source/drain region and the p+ channel stop.

Abstract: An apparatus for providing automatic gain control for use in a satellite terminal of a satellite communication system capable of transmitting a plurality of different modes of data. The apparatus includes a demodulator circuit having an analog to digital converter; a first variable attenuator having an attenuation value set on the basis of a measured power level of a predetermined data signal; and a second variable attenuator having an attenuation value set on the basis of the mode of data being received by the satellite terminal, where each of the data modes have a corresponding predetermined attenuation value associated therewith which is utilized as the attenuation value of the second variable attenuator when the satellite terminal receives the data mode.

Abstract: A system and method for pointing a non-tracking antenna in a geo-synchronous satellite-based communication system is provided. A satellite terminal antenna is initially pointed towards the target satellite by any desired method. The antenna bore sight is then aligned towards the center of a satellite station-keeping box for operational use. By pointing the antenna bore sight towards the center of the satellite station-keeping box, the largest excursion between the antenna's bore sight and the actual satellite position is no greater than half the diagonal of the satellite station-keeping box despite the fact that satellite will move within the satellite station-keeping box's outer limits after the installation of the non-tracking antenna.

Abstract: In a medium earth orbit (MEO) satellite system, an embodiment of the present invention employs a system and method for administering mobility management issues for mobile terminals, via a network of base station controllers. The mobility management issues, for example, paging, routing, and handover of communication signals are administered between the base station systems without having to be routed through the serving general packet radio service support node (SGSN).

Abstract: A torque motor includes an annular, cylindrically symmetric, stationary inner support ring having an outer surface, and a plurality of inner permanent magnets affixed to the outer surface of the inner support ring. The torque motor further includes an annular, cylindrically symmetric, stationary outer support ring overlying the inner support ring and having an inner surface, and a plurality of outer permanent magnets affixed to the inner surface of the outer support ring. There is an annular, cylindrically symmetric, rotationally movable rotor body ring lying between the inner support ring and the outer support ring, wherein the movable rotor body ring has a plurality of openings therethrough. A plurality of electromagnet rotor coils is supported in the openings on the movable rotor body ring.