Abstract: A method for transmitting data packets of at least two different priority levels via one or more bearer channels is described. The method comprises the steps of fragmenting a data packet into a plurality of corresponding code words, each code word comprising a sync code, with the sync code being adapted for indicating a priority level of the corresponding data packet, and of transmitting the code words via the one or more bearer channels. In case high priority code words corresponding to a high priority data packet arrive during transmission of low priority code words corresponding to a low priority data packet, the following steps are performed: interrupting transmission of low priority code words, transmitting the high priority code words corresponding to the high priority data packet, and resuming the transmission of the low priority code words via the one or more bearer channels.

Abstract: 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.

Abstract: A DSL transmitter and receiver are disclosed that efficiently estimate crosstalk interference. When transmitting over a DSL cable, each of the lines of the cable cause interference in the signals traveling though the other lines in the form of crosstalk. In order to reduce the complexity of the crosstalk estimation calculations, the transmitter sends a measurement signal whose matrix includes a plurality of sub-matrices that include less than all of the signal slots and are modulated with QAM +1s or ?1s. Meanwhile, the remaining signal slots are modified with QAM 0 s, which do not require any processing during the crosstalk estimation. Rather than calculating crosstalk vectors of all lines, the receiver need only calculate the crosstalk vectors for the signal slots contained within the sub-matrices, thereby significantly reducing complexity.

Abstract: 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.

Abstract: The present disclosure extends the flow control in a DSL communication system to include a remote back-pressure flow control within a DSL receiver of the DSL communication system. The remote back-pressure flow control can prevent a DSL transmitter of the DSL communication system from overwhelming the DSL receiver. The remote back-pressure flow control is implemented within a receiving network processor (rx-NP) of the DSL receiver to prevent the DSL transmitter from overwhelming the rx-NP.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A DSL transmitter and receiver are disclosed that efficiently estimate crosstalk interference. When transmitting over a DSL cable, each of the lines of the cable cause interference in the signals traveling though the other lines in the form of crosstalk. In order to reduce the complexity of the crosstalk estimation calculations, the transmitter sends a measurement signal whose matrix includes a plurality of sub-matrices that include less than all of the signal slots and are modulated with QAM +1s or ?1s. Meanwhile, the remaining signal slots are modified with QAM 0 s, which do not require any processing during the crosstalk estimation. Rather than calculating crosstalk vectors of all lines, the receiver need only calculate the crosstalk vectors for the signal slots contained within the sub-matrices, thereby significantly reducing complexity.

Abstract: 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.

Abstract: 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—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.

Abstract: A system and method for changing retransmission and rescheduling queues to support retransmission in a communications system is presented. A method for changing queue size values includes, for an increase in data rate, determining a new retransmission queue size value for a retransmission queue at the transmitting device and a new rescheduling queue size value for a rescheduling queue at the receiving device such that an amount of time for a DTU to enter and exit the retransmission queue is greater than a roundtrip delay. For a decrease in data rate, the method includes determining the new retransmission queue size value and the new rescheduling queue size value such that an amount of time for a DTU to enter and exit the retransmission queue is less than a maximum delay. Systems and methods for changing the retransmission and rescheduling queue sizes are also presented.

Abstract: The present invention provides digital subscriber line noise mitigation techniques, and applications thereof. In an embodiment, the present invention provides a toolbox of methods and techniques for mitigating the effects of noise in xDSL systems. These methods and techniques are controllable and locatable at one or both ends of a DSL communication link (e.g., within a central office transceiver unit or a remote transceiver unit). These novel methods and techniques include: (1) per tone noise margin modification, (2) data framer constraints modification, (3) improved noise measurements; (4) more robust on-line reconfiguration processes, (5) worst case noise monitoring, (6) induced bit rate limitations, and (7) distortion noise mitigation. These methods and techniques are particularly useful for mitigating the effects of time-varying noise and impulse noise.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.