Broadcom Corporation

Ravi Bhaskaran

David Hartman

Adel Fanous

Mark Dale

Alan Gin

Dorothy D Lin

Jen-chieh Chien

Rocco J Brescia, Jr

Thomas J Kolze

Bruce Joseph Currivan

Ba-Zhong Shen

Rocco Brescia

Jonathan S Min

Tak Kwan Lee

Loke Kun Tan

Fang Lu

Kevin Lee Miller

Jeffrey Scott Putnam

Thuji Simon Lin

Gopal Triplicane Venkatesan

James P Cavallo

Hsin-An Liu

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.

Upstream adaptive modulation in a communications system

A method of transmitting data in a cable modem system includes the steps of encoding the data using forward error correction. The data is then encoded with Turbo encoding. The data is then sent to a modulation scheme. The data is then transmitted over a cable channel. The data is then demodulated. The data is then decoded using a Turbo decoder. An inverse of the forward error correction is then applied to the data.

Turbo coding for upstream and downstream transmission over a channel

Turbo coding for upstream and downstream transmission in cable systems

A method, apparatus and computer program product for generating and processing upstream channel descriptor (UCD) messages in a DOCSIS-based broadband communications system, such as a DOCSIS-based two-way satellite communications system, is provided. A satellite modem termination system (SMTS) generates a UCD message that includes one or more standard parameters pertaining to an upstream channel of the two-way satellite communications system, wherein the one or more standard parameters are defined in accordance with the DOCSIS protocol, and one or more satellite application-specific parameters pertaining to the upstream channel, wherein the one or more satellite application specific parameters are not provided for by the DOCSIS protocol. The UCD message is transmitted to a satellite modem that extracts both the standard and satellite application-specific parameters for use in managing communication over the upstream channel.

Modified upstream channel descriptor messages for DOCSIS-based broadband communication systems

A system and method for requesting additional bandwidth in a communications channel between one or more first satellite terminal devices and a second satellite terminal device, are provided. The method includes identifying an available field in a header to be transmitted from the one or more first devices to the second device and allocating at least a portion of the available field for requesting the additional bandwidth. A size of the available field is reconfigurable. The method also includes forwarding the extend header to the second device.

Queue depth extended headers for DOCSIS based broadband communication systems

Satellite communications are carried out using the Data Over Cable Interface Specification (DOCSIS). Satellite modems are notified of upstream channel congestion by inserting a congestion notification message in a medium access protocol (MAP) message for the upstream channel. Specifically, the congestion notification message is inserted in an unused field of the MAP message, such as the explicit congestion notification (ECN) field. The MAP message can also carry other characteristics of the upstream channel, including priority threshold, multicast access burst availability, and available bandwidth.

Explicit congestion notification for DOCSIS based broadband communication systems

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.

Upstream frequency control for docsis based satellite systems

Upstream adaptive modulation in DOCSIS based applications

All digital reference frequency locking. An all digital approach is provided for operation within one or more CMs within a cable modem communication system to lock the upstream of the one or more CMs to the downstream symbol clock provided from a CMTS. The locking of the CM's upstream may be performed using one of at least three different functions: (1) Locking the upstream symbol clock phase to the downstream symbol clock phase, (2) Locking the downstream symbol clock phase to the headend reference clock phase (typically 10.24 MHz or integer multiple thereof), and (3) Locking the upstream carrier frequency to the downstream symbol clock frequency. The all-digital techniques for supporting all digital reference frequency locking functionality provide high performance to support S-CDMA and other synchronous modulation techniques.

All digital reference frequency locking

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Irvine, CA, United States of America

Ravi Bhaskaran