Abstract: The present invention relates to a device (108, 109, 110) comprising an interface to at least one active subscriber line (112) and an interface to at least one inactive subscriber line (111). The device (108, 109, 110) comprises means for transmitting a first signal on the inactive subscriber line (111) and means for synchronously measuring crosstalk (130; 201, 203, 205, 207) induced into the active subscriber line (112) by transmitting the first signal on the inactive subscriber line (111).

Abstract: A transmitter device (210) and associated receiver device (211) providing a retransmission scheme for use in communications involving lossy media. The transmitter device (210) receives data packets (201) from a source and adds protection to selected subflows before delivering (203, 206) them to the receiver device (211). The receiver device (211) is able to remove the protection and process (207) the data packets further. The retransmission scheme introduces greater reliability on the lossy medium by restricting the retransmission (208, 209) to a particular link and to selected subflows of traffic in the connection between a source and a destination.

Abstract: The present invention relates to a method for data-flow quality control in a Digital Subscriber Line communications system comprising a transmitter, a receiver, and a Digital Subscriber Line intercoupling the transmitter and the receiver. The transmitter sends a data-flow to the receiver, where the data-flow is modulated onto data-carriers according to a bit allocation indicative for the number of bits to be modulated on each data-carrier. The method comprises the steps of the receiver measuring the data-flow quality and subsequently the receiver instructs the transmitter to decrease the bit allocation with a same amount for a plurality of data-carriers in case the data-flow quality is unsatisfactorily low. Then the transmitter decreases the bit allocation accordingly.

Abstract: A method involves performing a plurality of acts. The acts include transmitting a first signal stream to a first channel of a multi-channel communications medium while transmitting a second signal stream to a different second channel of the medium. The second signal stream is substantially temporally correlated to the first signal stream. The method includes receiving an SINR measured at a receiver configured to receive signals from the first channel. The SINR is measured while the receiver received the first signal stream. The method includes determining a channel matrix element between the first and second channels or a ratio of said channel matrix element to a diagonal element of the channel matrix. The act of determining is based on the received SINR.

Abstract: A method for determining at least one operational transmit power Snk over a communication channel (Ln) coupled to a disturbance causing transceiver (n) for at least one tone (k), comprises the steps of provision of at least one reference victim communication channel (Lref) for representing at least one reference victim for all victim communication channels which are degraded by cross-talk interferences by said communication channel (Ln), and maximizing the data rate (Rref) over said at least one reference victim communication channel (Lref) under the constraint that the data rate over said communication channel (Ln) achieves a target rate (Rntarget) without exceeding a power constraint (Pnmax).

Abstract: The present invention relates to a method for determining a transmit PSD over a remotely-deployed line, which method comprising the steps of: modeling a first far-end crosstalk originating from the line and coupling into a centrally-deployed victim neighboring line, modeling a second far-end crosstalk originating from a further centrally-deployed neighboring line and coupling into the victim neighboring line, determining the transmit PSD from the first modeled far-end crosstalk and the second modeled far-end crosstalk. A method according to the invention further comprises the steps of: expressing the transmit PSD as a function of a line parameter characterizing a line segment of the further neighboring line, carrying out channel measurements of a spare line that connects the central location to the remote location, and that shares common transmission characteristics with the line segment, estimating from said channel measurements a value of the line parameter, determining therefrom the transmit PSD.

Abstract: A method involves performing a plurality of acts. The acts include transmitting a first signal stream to a first channel of a multi-channel communications medium while transmitting a second signal stream to a different second channel of the medium. The second signal stream is substantially temporally correlated to the first signal stream. The method includes receiving an SINR measured at a receiver configured to receive signals from the first channel. The SINR is measured while the receiver received the first signal stream. The method includes determining a channel matrix element between the first and second channels or a ratio of said channel matrix element to a diagonal element of the channel matrix. The act of determining is based on the received SINR.

Abstract: The present invention relates to a device (108, 109, 110) comprising an interface to at least one active subscriber line (112) and an interface to at least one inactive subscriber line (111). The device (108, 109, 110) comprises means for transmitting a first signal on the inactive subscriber line (111) and means for synchronously measuring crosstalk (130; 201, 203, 205, 207) induced into the active subscriber line (112) by transmitting the first signal on the inactive subscriber line (111).

Abstract: A method for determining transmission characteristics over a first communication path and a second communication path, while an amount of the signal transmitted over the first communication path couples into the second communication path. In case of excess of capacity over the first communication path and a shortage of capacity over the second communication path, the transmit power over said first communication path is decreased such that the requested service is met over both communication paths. This optimal transmit power can be determined by trying successive transmit power values until the requested service is met, e.g. by means of a dichotomy algorithm or the like. The optimal transmit power value can be computed directly as well, e.g. by making use of the transfer characteristics of the coupling path. A transceiver unit may also be used to implement the present method.

Abstract: The present invention relates to a method for data-signal quality control, a related receiver and a related transmitter in an XDSL communications system, where this XDSL communications system comprises a transmitter and a receiver. The transmitter is coupled to the receiver over an XDSL line, over which the transmitter sends a data-signal on a plurality of data carriers for carrying this data-signal from the transmitter to the receiver. This receiver analyses a quality of the data-signal received by the receiver and subsequently requests the transmitter, in case this quality of the data-signal is beneath a predefined level to improve the quality of the data-signal, by performing an equal transmit power increase over a plurality of the data-carriers. The transmitter in response to the requesting improves the data-signal by performing an equal transmit power increase over at this plurality of data-carriers.

Abstract: A transmitter device (210) and associated receiver device (211) providing a retransmission scheme for use in communications involving lossy media. The transmitter device (210) receives data packets (201) from a source and adds protection to selected subflows before delivering (203, 206) them to the receiver device (211). The receiver device (211) is able to remove the protection and process (207) the data packets further. The retransmission scheme introduces greater reliability on the lossy medium by restricting the retransmission (208, 209) to a particular link and to selected subflows of traffic in the connection between a source and a destination.

Abstract: A power control method for transceiver units conveying data over discrete tones. The method includes the steps of: determining a transmit power over a physical channel for each individual tone, such that this transmit power maximizes a weighted function of data rates achievable with this tone over the physical channel and over modeled neighboring channels, with the constraint that this transmit power conforms to a transmit power mask, summing up the data rates over the whole set of tones, adjusting the weights such that the total data rates over the modeled neighboring channels reach some target data rates, and such that the total data rate over the physical channel is maximized, with the constraint that each weight is identical over the whole set of tones.

Abstract: A method for determining at least one operational transmit power Snk over a communication channel (Ln) coupled to a disturbance causing transceiver (n) for at least one tone (k), comprises the steps of provision of at least one reference victim communication channel (Lref) for representing at least one reference victim for all victim communication channels which are degraded by cross-talk interferences by said communication channel (Ln), and maximizing the data rate (Rref) over said at least one reference victim communication channel (Lref) under the constraint that the data rate over said communication channel (Ln) achieves a target rate (Rntarget) without exceeding a power constraint (Pnmax).

Abstract: The present invention relates to a power control method for transceiver units conveying data over discrete tones. The present invention has application interalia for remotely deployed communication service, and achieves significant performance gains over existing methods.