摘要:
A system and method for providing upstream adaptive modulation. Burst parameters associated with a range of data interval usage codes (IUCs) are defined. Each of the data IUCs has a different modulation order and forward error correction (FEC). The SNR and codeword error rate for each satellite modem in the network are monitored. The data IUCs are dynamically assigned to different satellite modems within an upstream channel based on SNR and/or codeword error rate to enable each of the satellite modems in the upstream channel to achieve maximum bandwidth efficiency during upstream data transmissions. Bandwidth requests are received from the satellite modems and granted. The grant includes the assigned data IUC. The data bursts received in the upstream channel are each processed using the parameters from the assigned IUC for each of the satellite modems sending data in the upstream channel. When any of the satellite modems' SNR and/or codeword error rate changes, the data IUC for that satellite modem is changed accordingly.
摘要:
A system and method for providing upstream adaptive modulation. Burst parameters associated with a range of data interval usage codes (IUCs) are defined. Each of the data IUCs has a different modulation order and forward error correction (FEC). The SNR and codeword error rate for each satellite modem in the network are monitored. The data IUCs are dynamically assigned to different satellite modems within an upstream channel based on SNR and/or codeword error rate to enable each of the satellite modems in the upstream channel to achieve maximum bandwidth efficiency during upstream data transmissions. Bandwidth requests are received from the satellite modems and granted. The grant includes the assigned data IUC. The data bursts received in the upstream channel are each processed using the parameters from the assigned IUC for each of the satellite modems sending data in the upstream channel. When any of the satellite modems' SNR and/or codeword error rate changes, the data IUC for that satellite modem is changed accordingly.
摘要:
A system and method for minimizing the frequency error of satellite modem signals at a satellite gateway. The gateway downstream baud (symbol) clock and the elements that control the upstream frequency (i.e., local oscillators in the conversion chain, A/D sample clocks) are locked to a common frequency reference. The gateway sends upstream satellite frequency offset information, such as satellite ephemeris data from which to calculate Doppler offset, to the satellite modem. The satellite modem locks the frequency of the satellite modems master oscillator to the recovered baud rate using a frequency locked loop. The satellite modem uses its master oscillator as the carrier reference for the upstream frequency up conversion. The satellite modem uses or calculates the upstream satellite frequency offset and compensates for this offset by shifting its center frequency.
摘要:
A system and method for providing upstream adaptive modulation. Burst parameters associated with a range of data interval usage codes (IUCs) are defined. Each of the data IUCs has a different modulation order and forward error correction (FEC). The SNR and codeword error rate for each satellite modem in the network are monitored. The data IUCs are dynamically assigned to different satellite modems within an upstream channel based on SNR and/or codeword error rate to enable each of the satellite modems in the upstream channel to achieve maximum bandwidth efficiency during upstream data transmissions. Bandwidth requests are received from the satellite modems and granted. The grant includes the assigned data IUC. The data bursts received in the upstream channel are each processed using the parameters from the assigned IUC for each of the satellite modems sending data in the upstream channel. When any of the satellite modems' SNR and/or codeword error rate changes, the data IUC for that satellite modem is changed accordingly.
摘要:
A system and method for providing upstream adaptive modulation. Burst parameters associated with a range of data interval usage codes (IUCs) are defined. Each of the data IUCs has a different modulation order and forward error correction (FEC). The SNR and codeword error rate for each satellite modem in the network are monitored. The data IUCs are dynamically assigned to different satellite modems within an upstream channel based on SNR and/or codeword error rate to enable each of the satellite modems in the upstream channel to achieve maximum bandwidth efficiency during upstream data transmissions. Bandwidth requests are received from the satellite modems and granted. The grant includes the assigned data IUC. The data bursts received in the upstream channel are each processed using the parameters from the assigned IUC for each of the satellite modems sending data in the upstream channel. When any of the satellite modems' SNR and/or codeword error rate changes, the data IUC for that satellite modem is changed accordingly.
摘要:
A system and method for providing upstream adaptive modulation. Burst parameters associated with a range of data interval usage codes (IUCs) are defined. Each of the data IUCs has a different modulation order and forward error correction (FEC). The SNR and codeword error rate for each satellite modem in the network are monitored. The data IUCs are dynamically assigned to different satellite modems within an upstream channel based on SNR and/or codeword error rate to enable each of the satellite modems in the upstream channel to achieve maximum bandwidth efficiency during upstream data transmissions. Bandwidth requests are received from the satellite modems and granted. The grant includes the assigned data IUC. The data bursts received in the upstream channel are each processed using the parameters from the assigned IUC for each of the satellite modems sending data in the upstream channel. When any of the satellite modems' SNR and/or codeword error rate changes, the data IUC for that satellite modem is changed accordingly.
摘要:
A modified ranging request in a broadband communications system. The modified ranging request includes a header, a management message header attached to the header, a management message payload attached to the management message header, and a CRC attached to the management message payload. The management message header enables bandwidth requests to be made by subscriber equipment without contention. The management message header also includes state of health information on the status of a downstream transmission for enabling a central location to determine how to assign subscribers to queues in an adaptive modulation scheme.
摘要:
A modified ranging request in a broadband communications system. The modified ranging request includes a header, a management message header attached to the header, a management message payload attached to the management message header, and a CRC attached to the management message payload. The management message header enables bandwidth requests to be made by subscriber equipment without contention. The management message header also includes state of health information on the status of a downstream transmission for enabling a central location to determine how to assign subscribers to queues in an adaptive modulation scheme.
摘要:
A satellite communication system includes a satellite earth station operably coupled to a data network, and a plurality of satellite modems, each satellite modem of the plurality of satellite modems communicating in an upstream and downstream data communication mode with the satellite earth station via at least one servicing satellite. The satellite earth station includes a host processor for receiving data packets from the data network and processing DOCSIS management packets, a DOCSIS MAC coupled to the host processor for encrypting the transmit packet data from the host memory, framing data in MAC headers and inserting MAC timestamps in the transmit packet data, a satellite modulator coupled to the DOCSIS MAC for modulating the encrypted transmit packet data to generate downstream output data for transmission to at least one of the plurality of satellite modems, a burst demodulator for demodulating upstream data received from at least one of the plurality of satellite modems, and a turbo decoder coupled to the burst demodulator and the DOCSIS MAC for turbo decoding the demodulated data from the burst demodulator and sending the decoded data to the DOCSIS MAC. The DOCSIS MAC sends DOCSIS management packets portion of the decoded data to the host processor and sends transmit packet data portion of the decoded data to the data network.
摘要:
A satellite communication system includes a satellite earth station operably coupled to a data network, and a plurality of satellite modems, each satellite modem of the plurality of satellite modems communicating in an upstream and downstream data communication mode with the satellite earth station via at least one servicing satellite. The satellite earth station includes a host processor for receiving data packets from the data network and processing DOCSIS management packets, a DOCSIS MAC coupled to the host processor for encrypting the transmit packet data from the host memory, framing data in MAC headers and inserting MAC timestamps in the transmit packet data, a satellite modulator coupled to the DOCSIS MAC for modulating the encrypted transmit packet data to generate downstream output data for transmission to at least one of the plurality of satellite modems, a burst demodulator for demodulating upstream data received from at least one of the plurality of satellite modems, and a turbo decoder coupled to the burst demodulator and the DOCSIS MAC for turbo decoding the demodulated data from the burst demodulator and sending the decoded data to the DOCSIS MAC. The DOCSIS MAC sends DOCSIS management packets portion of the decoded data to the host processor and sends transmit packet data portion of the decoded data to the data network.