Abstract: Method and apparatus for modeling a network are described in which a 1 port measurement is made on the network by inputting an excitation signal at one port of the network and recording the results reflected back to the port. A 1 port parametric model of the network is generated whereby as much information about the topology of the network is included in calculating initial values of the parameters. Then the values of the parameters of the 1 port parametric model are optimized by reducing the difference between the results of the measurement step and results calculated using the 1-port parametric model and the excitation signal.

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: A method for determining crosstalk coupling between a plurality of transmission lines in digital data transmission systems, in particular DSL networks. Firstly, at least one test signal (TS) is generated having a unique identification code (UIC) in the frequency domain (f), said code (UIC) being associated with a first transmission line. Then, the test signal (TS) is sent on the first transmission line. At least a second transmission line is monitored for detecting a crosstalk signal. It is determined whether the crosstalk signal is caused by the test signal (TS) of the first transmission line by means of a signature of the unique identification code (UIC) comprised in the crosstalk signal. In this way crosstalk between individual transmission lines can be determined without having to have recourse to conservative worst case assumptions. The method can adapt dynamically to a changing user/transmission environment, while obtaining unique crosstalk determination results at all times.

Abstract: A method and apparatus for modeling a network comprising a plurality of transmission lines is described, the method and system being adapted to measure loop parameters of first transmission line to provide measured loop parameters, determine a topology of the first transmission line by analyzing the measured loop parameters with reference to at least a one model of a plurality of models for transmission lines of different topologies, select a further model for estimating crosstalk related parameters based on the determined topology, and estimate at least one crosstalk related parameter based on the determined topolgy and the selected further model.

Abstract: The physical layer session resource broker (PHY SRB) according to the invention receives request from application servers (VOD SERVER, TV BRDCST SERVER, GAME SERVER, WEB SERVER) which are translated into physical layer parameter values. The physical layer parameter values are imposed on the access nodes (DSLAM) by the physical layer session resource broker (PHY SRB).

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: Interpretation systems for interpreting reflectometry information are provided with modules for making interpretations, with each module comprising a generating module-part, a testing module-part, and a debugging module-part, and with one module being a generating system-part for a next module and with said next module being a testing system-part and a debugging system-part for said one module, to introduce improved intelligence. These interpretation systems have double-level Generate-Test-Debug (GTD) structures, two at module level as well as one at system level. This improved intelligence can be further improved by introducing a third module resulting in three GTD structures at module level and two GTD structures at system level. Interpretations are pulse-based, energy-based, simulation-based for rough, medium, and precise interpretation for increasing the efficiency of the improved intelligence.

Abstract: A method for determining crosstalk coupling between a plurality of transmission lines in digital data transmission systems, in particular DSL networks. Firstly, at least one test signal (TS) is generated having a unique identification code (UIC) in the frequency domain (f), said code (UIC) being associated with a first transmission line. Then, the test signal (TS) is sent on the first transmission line. At least a second transmission line is monitored for detecting a crosstalk signal. It is determined whether the crosstalk signal is caused by the test signal (TS) of the first transmission line by means of a signature of the unique identification code (UIC) comprised in the crosstalk signal. In this way crosstalk between individual transmission lines can be determined without having to have recourse to conservative worst case assumptions. The method can adapt dynamically to a changing user/transmission environment, while obtaining unique crosstalk determination results at all times.

Abstract: Methods for matching adaptive hybrids (15) to lines (16) for making reflectograms of the lines (16) measure (1) input impedances (Zmeas) of the lines (16), model (2) characteristic impedances of the lines (16) via physical models (Zphymod), estimate (3) parameters of the physical models (Zphymod) via cost functions which depend on the measured input impedances (Zmeas), convert (30) the modelled characteristic impedances into impedance values (13), and set (31) the adaptive hybrids (15) with the impedance values (13). Unwanted near-end reflections are minimised and wanted reflections can be measured. The physical models depend on frequencies s, Bessel functions Ji and parameters ai related to geometrical dimensions A, D and L and material constants ?, ? and ? of the lines (16).

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: In the course of a reflectometry-based qualification procedure of a local loop, which connects customer premises to a central office of a telecommunication network, and in the event of being unable to identify the loop termination associated with the customer premises, a second reflectometry measurement of the local loop is carried out with a different impedance load at the customer premises. Next, the two reflectograms are compared with each other in the time domain in order to delineate among all the reflections those at the customer premises and to determine therefrom the position of the customer premises in the local loop.

Abstract: A crosstalk agent for integration in or connection to an access node (DSLAM) automatically gathers quantitative information indicative for the crosstalk coupling between lines (LINE1, LINE2, LINE3, LINE4) connected to the access node (DSLAM). The information may be extracted from an access node MIB each time the on/off state of a line changes, and optionally is used to group the lines in virtual binders. The crosstalk agent may optionally interface with service deployment or service upgrade experts, or with a dynamic spectrum management module in the access node (DSLAM).

Abstract: The physical layer session resource broker (PHY SRB) according to the invention receives request from application servers (VOD SERVER, TV BRDCST SERVER, GAME SERVER, WEB SERVER) which are translated into physical layer parameter values. The physical layer parameter values are imposed on the access nodes (DSLAM) by the physical layer session resource broker (PHY SRB).

Abstract: In the process of estimating attributes of a transmission line from reflectometry measurements, small yet important reflections may be drowned in the immediate reflected signal owing to the mismatch between the reference impedance with respect to which the 1-port scattering parameter of the line has been determined and the characteristic impedance of the line. The major part of the near-end reflections are eliminated by estimating the characteristic impedance of the line, and by converting the 1-port scattering parameter of the line from the reference impedance base to the estimated characteristic impedance base. However, there is still a residual influence of the near-end reflections. It is then highly necessary to determine a time zone wherein the residual near-end reflections are enclosed so as their contribution is further neutralized in the process of estimating attributes of the transmission line.

Abstract: Methods for matching adaptive hybrids (15) to lines (16) for making reflectograms of the lines (16) measure (1) input impedances (Zmeas) of the lines (16), model (2) characteristic impedances of the lines (16) via physical models (Zphymod), estimate (3) parameters of the physical models (Zphymod) via cost functions which depend on the measured input impedances (Zmeas), convert (30) the modelled characteristic impedances into impedance values (13), and set (31) the adaptive hybrids (15) with the impedance values (13). Unwanted near-end reflections are minimised and wanted reflections can be measured. The physical models depend on frequencies s, Bessel functions Ji and parameters ai related to geometrical dimensions A, D and L and material constants ?, ? and ? of the lines (16).

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.

Abstract: A method to provide cross-talk cancellation in a multiple input multiple output system that comprises a plurality of outputs is described. The method comprises a step determining during a first phase and according to a heuristic model, for a first signal to be transmitted to a first output of the plurality of outputs at least one dominant interfering tone of at least one second signal to be transmitted to a second output of the plurality of outputs. The at least one dominant interfering tone is in fact a tone of at least one second signal that would generate cross-talk upon the first signal when it would be transmitted to the first output. The method further comprises a step of executing a step of partial cross-talk cancellation for the first signal during a second phase for the one or more determined dominant interfering tones associated to one or another second signal.

Abstract: In the process of estimating attributes of a transmission line from reflectometry measurements, small yet important reflections may be drowned in the immediate reflected signal owing to the mismatch between the reference impedance with respect to which the 1-port scattering parameter of the line has been determined and the characteristic impedance of the line.

Abstract: In the course of a reflectometry-based qualification procedure of a local loop, which connects customer premises to a central office of a telecommunication network, and in the event of being unable to identify the loop termination associated with the customer premises, a second reflectometry measurement of the local loop is carried out with a different impedance load at the customer premises. Next, the two reflectograms are compared with each other in the time domain in order to delineate among all the reflections those at the customer premises and to determine therefrom the position of the customer premises in the local loop.

Abstract: Interpretation systems (IS) for interpreting reflectometry information are provided with modules (M1,M2) for making interpretations, with each module comprising a generating module-part (G1,G2), a testing module-part (T1,T2) and a debugging module-part (D1,D2), and with one module being a generating system-part for a next module and with said next module being a testing system-part and a debugging system-part for said one module, to introduce improved (for example artificial) intelligence. These interpretation systems (IS) have double-level Generate-Test-Debug-structure or GTD-structures, two at module level as well as one at system level. This improved intelligence can be (further) improved by introducing a third module (M3) resulting in three GTD-structures at module level and two GTD-structures at system level. Interpretations are pulse-based, energy-based, simulation-based for rough, medium, precise interpretation for increasing the efficiency of the improved intelligence.