Broadcom Corporation

Other

Broadcom Corpotation

Avago Technologies International Sales Pte. Limited

Raphael Paul Cassiers

Miguel Peeters

Benoit Christiaens

Rudi Verbist

Ruben Lysens

Olivier Van De Wiel

Benoit M S Christiaens

A DSL transmitter and receiver are disclosed that are capable of accurately measuring crosstalk in G.vector-compliant DSL lines resulting from a legacy line. During crosstalk measurement, the legacy line can be placed in a showtime mode. Once in showtime mode, a data signal designated for the legacy line is reduced in power spectrum density and/or spectrum to reduce its effects on crosstalk measurements. An O-P-Vector-1 signal is then superposed on the reduced data signal, and the resulting test signal is transmitted over the legacy line while sync signals are transmitted over neighboring G.vector lines. The receiver can then accurately measure the crosstalk on the neighboring lines, and report back to the transceiver for adjustments. A similar configuration can be performed in a diagnostic mode of the legacy line.

Communication system capable of measuring crosstalk in legacy line

A method for selecting a mode of operation for at least two modems is described. First, a handshake procedure is performed in order to determine a set of possible modes of operation supported by said modems. From said set of possible modes of operation, a set of favorable modes of operation is derived. In case there exist two or more favorable modes of operation, a probing-based selection is performed that comprises evaluating respective performances of said favorable modes of operation. The favorable mode of operation with the best performance is selected as a resultant mode of operation.

Probing-based auto moding

Embodiments described herein provide an apparatus for transmitting data in an xDSL. In one example, the apparatus can include a transmitter configured to transmit data over the xDSL system in the form of data transmission units (DTUs), the transmitter having a physical media specific-transmission convergence (PMS-TC) communication sublayer and a retransmission unit that is implemented in the PMS-TC sublayer, the retransmission unit including a retransmission buffer configured to store transmitted DTUs and to index the transmitted DTUs using retransmit containers, each retransmit container being defined as a time slot corresponding to a respective sent DTU. A retransmit request specifies a DTU by a corresponding retransmit container and wherein the retransmission unit is configured to retransmit the specified DTU in response to the retransmit request.

System for communicating data in xDSL using data retransmission

In one embodiment, a method for communicating data is provided. The method includes defining a data transmission unit (DTU) to be sent in an xDSL data stream, defining a retransmit container as a time slot that corresponds to the DTU, maintaining, in a retransmit container, a copy of the DTU and an index corresponding to the retransmit container, the retransmit container being maintained at the second device independently of the first device, transmitting the DTU in the xDSL data stream, determining whether the DTU should be retransmitted, and if the DTU should be retransmitted: identifying the DTU by the retransmit container and retransmitting a copy of the DTU as identified by the retransmit container when the DTU reaches a predetermined position in the retransmission buffer.

Method for communicating data in xDSL using data retransmission

An apparatus for transmitting data in an xDSL system is disclosed. In an exemplary embodiment, the apparatus comprises a transmitter that sends data over an xDSL system in the form of a data transmission unit (DTU), the transmitter having physical media specific&#x2014;transmission convergence (PMS-TC) communication sublayer. The apparatus may further include a retransmission unit that is implemented in the PMS-TC sublayer. The retransmission unit may include a retransmission buffer that stores and indexes transmitted DTUs in retransmit containers. The retransmit container may be defined as a time slot corresponding to a sent DTU, wherein the retransmission unit is configured to respond to a retransmission request indicating which stored DTU should be retransmitted. The stored DTU to be retransmitted may be identified by its corresponding retransmit container.

A method and system for communicating data in an xDSL data retransmission mode is disclosed. A data transmission unit (DTU) is defined. The DTU is sent in an xDSL data stream. A retransmit container is further defined a as a time slot that corresponds to a sent DTU. A copy of the sent DTUs and an index of corresponding retransmit containers is maintained. The DTUs are transmitted the in the xDSL data stream. A determination is made on whether a transmitted DTU was corrupted during transmission. Each corrupted DTU is identified by its corresponding retransmit container. An uncorrupted copy of the DTU is then retransmitted as identified by the corresponding retransmit container.

Method and system for communicating data in xDSL using data retransmission

A method for determining differential delay of at least two bonded links is described. The method comprises a step of providing, on the part of a transmitting entity, at least some of the data packets transmitted from the transmitting entity to a receiving entity with time stamps, the time stamps indicating a point of time when a respective data packet has been generated, and a step of deriving a propagation delay from a time stamp of a data packet and a time of arrival of the data packet at a receiving entity. The method further comprises a step of determining a differential delay of a link from the propagation delay of the link and a propagation delay of a reference link.

Differential delay compensation and measurement in bonded systems

In one embodiment, a method for communicating data is provided. The method includes, defining a data transmission unit (DTU) to be sent in an xDSL data stream, defining a retransmit container as a time slot that corresponds to the DTU, maintaining a copy of the DTU and an index corresponding to the retransmit container in a retransmission buffer, transmitting the DTU in the xDSL data stream, determining whether the DTU should be retransmitted, and if the DTU should be retransmitted: identifying the DTU by the retransmit container and retransmitting a copy of the DTU as identified by the retransmit container before the DTU leaves the retransmission buffer.

Methods, systems, and computer program products for reconfiguring a modem. In an embodiment, fast reconfiguration of a modem occurs when a first modem determines there is a need for fast reconfiguration. The first modem signals its transition from showtime to fast reconfiguration. The first modem waits for acknowledgement from a second modem before transitioning to showtime. Once transitioned from showtime, the first modem estimates a signal to noise ratio and then exchanges parameters with the second modem. The first and second modems then transition to showtime.

Fast modem reconfiguration

A method for transmitting data in an xDSL system is disclosed. In an exemplary embodiment, the method includes defining a data transmission unit (DTU) to be sent in an xDSL data stream, defining a retransmit container as a time slot that corresponds to a sent DTU, maintaining a copy of the sent DTUs and an index of corresponding retransmit containers in retransmission buffer, transmitting the DTUs in the xDSL data stream, determining whether a transmitted DTU should be retransmitted, identifying each corrupted DTU by its corresponding retransmit container, and retransmitting an uncorrupted copy of the DTU as identified by the corresponding retransmit container. The retransmission is deferred until the DTU is at a predefined position in the retransmission buffer.

An upstream signal power in a communication system is optimized. At least one system parameter is determined and a bits and gains table is modified. For example, a maximum received power parameter for the transmitting device is used by the receiving device to calculate a power backoff parameter. The power backoff parameter is used to calculate the bits and gains table which is then used by the transmitting device. The new SNR may be estimated. This estimation may distinguish between noise sources that vary with the signal level received and those that do not.

Upstream power cutback

A method of optimizing a communication system for receiving and processing an input communication signal includes selecting a first noise margin m to be applied against an external noise present on the input communication signal. The method further includes selecting a second noise margin mto be applied against an internal noise introduced on the communications signal by the communication system. The second noise margin is a predetermined function of the first noise margin. The method also includes calculating a virtual noise to signal ratio that is a combination of an external noise to signal ratio NSR, an internal noise to signal ratio NSR, the first noise margin and the second noise margin. The method further includes adjusting one or more system parameters so as to maintain the virtual noise to signal ratio at a predetermined margin above a required noise to signal ratio.

Method of and system for optimizing the capacity of a digital communication system in presence of both internal and external noise

The present invention provides systems and methods for pseudo-random signal generation in a multi-carrier communications system. In embodiments, a transmitter includes a pseudo-random bit sequence (PRBS) generator and Medley signal generator. The PRBS generator can operate in at least one of the following modes: a parameter selection mode, a scrambler mode, and/or a combination mode. The Medley signal generator receives an output bit sequence from the PRBS generator. The Medley signal generator then generates a Medley signal which includes a set of Medley tones encoded based on the output bit sequence from the PRBS generator. The Medley signal is then sent over channels of a multi-carrier communication system such as an ADSL system.

Growing community of inventors

Waterloo, Belgium

Raphael Paul Cassiers