Adaptive margin and band control in DSL system

The invention relates generally to the control or management of digital communication systems, such as an adaptive control of various transmission parameters, such as the maximum transmission power spectral density, maximum total transmission power, transmission band preference, the minimum and maximum reception margin of the receiver, the frequency-dependent bit loading and power controls and / or bit loading restrictions.

Digital subscriber line (DSL) technologies provide potentially large bandwidth for digital communication over existing telephone subscriber circuits (referred to as loop and / or copper systems). Telephone subscriber circuits, despite their original design, can only provide this bandwidth for analog voice band communication. In particular, the asymmetrical DSL (so-called. ADSL) to the characteristics of the subscriber circuit by using a discrete multi-tone (DMT) line code that assigns a number of bits to each tone (or subcarrier), which can be set to channel conditions that occur during a training process and initialization of the modems (typically transceivers that serve as both transmitters and receivers) at each end of the subscriber line. Adaptive mapping can continue during a live data transmission on channels or lines that vary over time through a process often referred to as bit swapping, which uses a safe, relatively slow, reverse channel to inform the sender of changes used in the mapping.

Impulse noise, other noise, and other sources of error can significantly affect the accuracy of data transmitted by ADSL and other communication systems. Various techniques have been developed to reduce, avoid and / or repair the damage caused to the data by such an error in transit. These failure reduction / avoidance / repair techniques incur performance costs for the communication system in which they are used. As is known in the art, inadequate power transmission levels lead to errors because the transmission power is not high enough to overcome noise and other interference in a particular channel. These errors result in data loss or the need to retransmit the data, sometimes multiple times. To avoid such errors, systems use additional transmission power that leads to reception margins above a known or calculated signal-to-noise ratio (SNR), which guarantees the tolerance of an acceptable error rate.

In general, DSL modem pairs determine performance, headroom, and other operational characteristics of the pair during the initialization, training, channel analysis, and exchange phases prior to full operation (sometimes referred to as SHOWTIME). The process begins with a power spectral density (PSD) value, or a mask. This can be a flat or constant (that is, frequency-independent) value or can be a variable mask, the PSD value being frequency-specific or frequency-dependent. In various DSLs there is an initial PSD value (sometimes referred to as NOMPSD) and usually an upper NOMPSD limit MAXNOMPSD is defined by an applicable standard for a particular country. From this initial PSD value, the modems estimate the line loss and line length (and perhaps other parameters and / or values).

From the line loss and length estimates, one or both modems can define a power cutback (PCB) value that decreases the initial PSD value. As indicated below, different DSL standards set the performance (for example PSD and PCB) according to different rules, provided that the standards are observed and complied with at all.

On the basis of the PSD value set once (sometimes as REFPSD = PSD - PCB / 54

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AT 13 387 U2 2013-11-15), the modems calculate the bit loading (bi), amplifications (g,) and the reception margin during the channel analysis phase. The gains g i are adjustments to individual transmission power levels of bit-loaded tones in the DMT scheme, which provide a relatively uniform reception margin for the transmission of data on the line. Gains can be adjusted during SHOWTIME to reflect changes in line conditions, etc., but can be severely limited in the extent of adjustment and in the manner in which such gain adjustments can be made.

Depending on the device manufacturer and the DSL standard used, compliance with the rules and guidelines of each standard and / or other suitable operational limits varies from strict compliance by some parties (which usually results in a very conservative or cautious setting of DSL service rates in the company) up to massive disregard of even fundamental company guidelines and rules. In many cases, whether due to deliberate or unintentional non-compliance, excessive power and / or reception margins are used in an attempt to avoid problems that may result from too little of either or both.

However, excessively high power transmission levels lead to other problems. For example, the use of excessive transmission power on one or more lines can cause severe crosstalk problems and interference in nearby lines. Crosstalk is unwanted interference and / or signal noise that is passed on electromagnetically between lines that share the same or neighboring connections . In addition, the use of a transmission power above the necessary levels also means that the communication system is operated more expensively to the detriment of all users. The following is a brief summary of existing standards and practices for several types of DSL service to which embodiments of the invention disclosed below may apply, including nuances that differ from any particular standard from the more general initialization, training, channel analysis and exchange procedure, as set out above.

ADSL1 - G.992.1 standard (also referred to here as ADSL1 standard or ADSL1):

(1) Has a limit setting for the maximum reception margin MAXSNRM (or equivalent) that can be set by vendors, but the ability to observe and implement this limit varies with the modem manufacturer and interpretations of the standard with which Result that it is often effectively ignored. In general, an operator is a telecom or other service provider that operates the network and provides the service as such. Internet service providers are generally not considered an operator as they usually subcontract the service to another party.

(2) ATU-R (Downlink Receiver) and ATU-C (Uplink Receiver) are limited to a 14.5 dB maximum gain reduction request, which is often insufficient to implement the purpose of MAXSNRM. Furthermore, some ATU-R modems ignore MAXSNRM and there has never been an interoperability test to declare such modems non-compliant with G.992.1 which actually determines that the reception margin does not exceed MAXSNRM.

(3) Downlink ATU-C transmitters reduce power by up to 12 dB according to the algorithms in the appendices of G.992.1 (the most popular of which are appendices A, B and C) when used in early training received upstream signals are large, indicating that the loop is short. The algorithms of Appendices A, B and C are blind to an output noise of the downlink channel and are therefore very cautious in reducing the power and almost always do not reduce the power sufficiently - for example, the commonly used Appendix A algorithm only applies to lines one Less than 1000 m (3000 feet) in length and thus does not do justice to many situations where longer lines also needed a derating.

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(4) An initial, flat upper PSD limit or mask can be programmed according to a MAXNOMPSD parameter which is between -40 and -52 dBm / Hz in 2 dB steps. The MAXNOMPSD value is set by the operator and is the maximum value that NOMPSD can assume when initiating transmitter-receiver training. The modem manufacturer can set a modem to use a lower NOMPSD value, in which case NOMPSD &lt;MAXNOMPSD applies. The MIB / Telkom operator can only set MAXNOMPSD in earlier systems, but cannot influence the NOMPSD value itself. In ADSL1, NOMPSD is communicated during training from the transmitter to the receiver (for a subsequent attenuation calculation). Here, too, there is no MIB parameter that specifies NOMPSD directly in ADSL1. Usually, MAXNOMPSD is the NOMPSD used in the very first transceiver training phase of ADSL1, but the NOMPSD level (limited only to be less than or equal to MAXNOMPSD) is determined by the modem manufacturer at the design stage and not by the operator set. Thus, by setting MAXNOMPSD, the operator is guaranteed that NOMPSD is set to an upper limit level of NO-MPSD - 2n_PCB dBm / Hz, as defined, is decreased, where n_PCB = 0 to 6 (i.e. if NOMPSD is -40 then the PSD power can be decreased by 0, 2, 4, 6, 8, 10 or 12 dB).

(5) ATU-R receivers from some manufacturers ignore the MAXSNRM altogether and never require the 14.5 dB power reduction, although such power reduction is required by the operator and standards.

(6) A gain change during live operation can be so limited (and is recommended in Appendix A, but not required) that only ± 2.5 dB gain settings are possible after training in the SHOWTIME. This means that a gain change in some modems is limited to a total of ± 2.5 dB in ADSL1. If a gain is not reduced sufficiently during training for any reason (for example there is disturbing noise), a further reduction only takes place if the modem relearns. A record of relearning processes (a relearning process count) can be kept by the DSL system as an indication of how many relearning processes were carried out in a certain period of time and as an indication that the MAXSNRM level could be set too low if the relearning process count is too high. Gain changes are applied sequentially in ADSL1 (so that they can build on each other), but the total gain decrease of a SHOWTIME sequence of gain changes is often limited to a maximum of ± 2.5 with respect to training. However, some vendors require a series of gain reductions that result in the full ADSL1-allowable gain reduction of -14.5 dB during the SHOWTIME. If changes of less than -2.5 dB are required, the receivers in such full-range gain change systems must be intelligent enough to adjust the internal signal processing in order to avoid intersymbol interference from the fixed synch symbol (the power of which is never reduced by gain changes during the SHOWTIME , unlike the other 68 live data symbols). Some bad receivers ask for the power reduction, but then cannot adjust themselves internally if this gain reduction, which is less than -2.5 dB, is implemented (and operators simply do not know which lines these bad receivers are on). Such a bad ATU-R then terminates the DSL connection, assuming the line is bad, when in fact the problem is due to the incorrect implementation of the ATU-R demanding a gain reduction that it cannot handle. Because of this problem, service providers could force DSLAM providers to always ignore power reduction requests that exceed the ± 2.5 dB range during live operation (and do this network-wide, since they do not know where the defective receivers are, which means that all good Recipients can be restricted). This further limits a reduction in performance if the service provider selects this option so that the defective receivers that are already installed in their network do not have to be exchanged.

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ADSL2 - G.992.3 Standard (also referred to here as ADSL2 Standard or ADSL2):

(1) Has a MAXSNRM setting, but this function has yet to be implemented by a DSL receiver.

(2) The ATU-R (as the downstream receiver) and ATU-C (as the upstream receiver) are limited to a 14.5 dB maximum power reduction requirement for gain settings that are now absolutely set in gain changes and not relative to last change of gain. The range now extends from -14.5 to [+2.5 + EXTGI], which is still limited to a maximum power reduction of 14.5 dB (EXTGI&gt; 0 and usually equal to 0; EXTGI is something the The transmitter notifies the receiver during the early training and that it can accept during later gain changes). A larger EXTGI value, up to the limit of 18 dB, allows a modem, which for some reason has a reduced performance, to increase its performance during live operation in order to react to a new higher noise that occurs during live operation could.

(3) A power reduction (PCB) in ADSL2 enables the receiver to reduce the power (only during training) by an additional 0.1, ..., 40 dB, so that the possibility of observing MAXSNRM improves will. The ADSL2 standard stipulates that the largest PCB required by either the sender or the receiver should then be implemented. MAXNOMPSD is still an operator controlled parameter in ADSL2 that applies to the entire band, but a wider range of this parameter is included in ADSL2 than in ADSL 1.

(4) The initial flat PSD mask can be programmed according to a MAXNOMPSD parameter that ranges between -40 (and -37 in certain extended range attachments of ADSL2, known as READSL) and -60 dBm / Hz in 0.1 dB steps.

(5) ATU-R receivers from some manufacturers can still ignore the performance degradation, and unfortunately this is not tested, even in the new DSLForum test procedure called WT-85 (although there is a test which almost all would pass, and there is no verification in this test that MAXSNRM is being observed). No band preference (ie frequency-dependent imposition of a PSDMASK) is possible in the ADSL2 standard itself.

(6) A gain change during the LIVE SHOWTIME is no longer limited to ± 2.5 dB and all symbols (there is still a synch symbol at every 69th position) have the same level. However, it is only possible to change the gain up to a reduction of -14.5 dB relative to the training level (not to the last level, as in ADSL1). A gain increase of up to 2.5 + EXTGI is particularly useful when the modem is started at very low power and there is noise. If EXTGI is large, the modem can recover without relearning. EXTGI is limited to 18.0 dB in ADSL2.

ADSL2 + G.992.5 standard (also referred to herein as the ADSL2 + standard or ADSL2 +):

(1) Same as ADSL2, with the exception of the introduction of the PSDMASK parameter, which is implemented by the tssi parameters. The tssi are additional parameters, such as the gains when the gain is changed, unless the tssi can be set externally.

VDSL1, VDSL2, HDSL and SHDSL

The current version of the proposed VDSL1 standard or G.993.1 has a limited definition of MIB controlled (or operator controlled) procedures for power degradation (the DSLAM or line termination (LT) modem manufacturer has a full PSDMASK internally -Specification, but access to this via MIB is in the best case not yet well defined in G.993.1). A list of the maintenance capabilities of the G.993.14 / 54

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Standards can be found in the DSL forum, document TR-057, but the MIB control section of TR-057 is currently empty. Thus, VDSL does not have a standardized mechanism for external setting of MAXNOMPSD, but has an internal mechanism for reducing the power in 0.25 dB steps (known as manual power control) between 0 and 40 dB for the uplink and 0 and 12 dB for the Downlink, in terms of nominally imposed standard limits (there are two mask levels and corresponding downlink and uplink transmission power levels, which can be programmed in G.993.1 -compliant modems - thus the power reduction is related to these, some of which are not yet specified). VDSL also specifies a MAXSNRM (but again it is not clear who specifies this). Hence, VDSL has many of the same capabilities as ADSL1 and ADSL2 / 2 +. These capabilities could be standardized for an operator interface in a MIB in future documents that could enable many of the same capabilities as ADSL1, ADSL2, and ADSL2 +. However, VDSL1 does not have the rich set of diagnostic reports like ADSL2 and ADSL2 +, or obviously even ADSL1, so being able to accurately diagnose a problem can be more difficult. Here, too, future generations of TR057 or G.997.X can address these deficiencies in the current VDSL MIB interfaces.

VDSL2 is still in the very early stages, but it appears that it will have essentially the same MIB features as ADSL2 +. HDSL does not appear to have degradation characteristics in any way. HDSL (now updated to SHDSL, G.991.2) has a target SNR (or TSNRM) and a reported SNRM, but no MAXSNRM. The bandwidth is fixed for any of a few data rates (in principle 384, 768, 1.5, 3, ...) symmetrical and has the same modulation in both directions with a certain standardized shape. A flat PCB of 0, ..., 31 dB can be imposed. There is no FEC at all to protect against pulses so the PCB is unlikely to be used much. Furthermore, SHDSL tends to run at the maximum rate possible on short lines, so their reception margin is usually close to the TSNRM of 6 dB.

The DSM report, still in its draft phase, currently has all the MIB capabilities of ADSL2 + in both directions and applies to all DMT transmission methods, ADSL1 to VDSL2 and beyond. FEC can also be specified.

As will be apparent to those skilled in the art, in many DSL systems, including ADSL1 and ADSL2 systems, operating characteristics and rules have usually been established for a static mode of operation in order to accommodate worst-case scenarios in the systems. That is, users do not always realize the full benefits of DSL systems because of inadequate standards, device limitations, and the flaws in generally accepted operating procedures and agreements. For example, power receipt margin limits are seldom observed or may conflict with or between different standards or interpretations of those standards. Such disregard of limits imposed by the service provider and / or set by standards creates problems for users, including excessive crosstalk. Impulse noise can also be a significant problem in some DSL systems. In order to deal with impulse noise, current systems use default settings for many operating parameters (such as reception margin) that are supplied by the manufacturer. The applicable standards are intended to enable the service provider to set these parameters, but may or may not be properly set by the various DSL modems or devices of the vendors.

Even if the majority of users (that is, their modems) conform to the standards in a connection, a single user can prove to be a significant cause of a deterioration in service or other damage to the DSL service of other users. For this reason, while the standards provide guidelines, even minimal non-compliance can create significant problems in current systems.

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AT 13 387 U2 2013-11-15 th default settings used in a DSL modem) means that the DSL service cannot adjust to changes in line and environmental conditions in the subscriber connection and adapt to them, which again results in the benefits that are in such DSL systems are available, destroyed and / or reduced and the potential available for one or more users in such systems is not realized. As will be apparent to those skilled in the art, the widely varying standards, equipment, implementation rules (or lack thereof) and practices mean that, despite detailed standards regarding the operation of these various DSL systems, consistent service and quality of service are challenging. Since the modems and other devices may or may not actually be compliant with the appropriate standards and, more importantly, the fact that adjacent lines of a user may or may not use standard compliant devices and practices, many users suffer from poor or suboptimal Services.

US 2002/141 443 A describes an arrangement for optimizing the bandwidth of DSL connections. A DSL connection is established via a subscriber device, a copper line connected to this subscriber device and a DSL access multiplexor that is connected to the copper line. The DSL connection is operated at a transmission rate that is adaptively optimized by an optimization unit based on a dynamic transmission environment.

US 6 229 855 B describes a method for controlling the power and / or the output frequency of transmitters in a digital data network. The transmission power and / or transmission frequency is controlled by line loss information as well as by noise bandwidth both in the central office and at remote points on the transmission link. Measurements of cable losses and SNR values ​​are carried out on the system, and the transmission power and / or frequency is adjusted in such a way that undesired interactions between transmitter / receiver pairs in the network are minimized.

A system and a method for adapting the performance of an xDSL communication system to customer requirements are known from WO 98/59426 A, a transmitter modem and a receiver modem agreeing on a performance parameter for the setting. The receiving modem measures the net signal-to-noise ratio on the xDSL loop, and on the basis of this measurement it sends a request to the transmitting modem to perform a specific setting of the selected performance parameter. The sending modem makes this setting after receiving the request from the receiving modem. The modems can select either the data rate or the transmission power as performance parameters for the setting.

US 6356585 B describes a digital subscriber modem which is connected to a line with a transmitting end and a receiving end. The modem contains a data terminal which connects the modem to the subscriber line and a control circuit which is connected to the data terminal and which sends signals to and receives signals from the data terminal. The control circuit uses line coding techniques to measure signals and noise at the receiving end and adjusts the signal amplitude according to the signal and noise, thereby optimizing signal performance.

EP 1 337 062 A discloses a method and a system for connection adaptation. A communication link is established between a central office (CO - central office) modem and a customer premise equipment (CPE) modem. The CO modem evaluates the performance of the communication link based on e.g. B. an SMR measurement, based on AGC (automatic gain control) levels, bit error rates or input power. Impairments to the communication link (e.g. crosstalk or eavesdropping bridges) are identified on the basis of the evaluation results. Setting parameters for improving the performance of the communication link are then determined. The CPE modem is modified in accordance with the specified setting parameters to provide an adapted communication connection

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AT 13 387 U2 2013-11-15 fertilize between the CO modem and the CPE modem, z. B. by a new carrier frequency for the uplink band or a new power level for the CPE modem (PBO - power back off - regulation of the power). This makes it possible to avoid impairments such as listening bridges and crosstalk.

US 6 327 677 describes a system and a method for monitoring a network environment. The system collects current data related to the operation of the network environment, and the network environment is analyzed by comparing the collected data with historical data associated with the operation of the network environment. The system determines whether a problem or a potential problem exists based on this analysis of the network environment. The system periodically updates the historical data to include the most recently collected data. The collected data can include network performance data, network configuration data, traffic flow data, network usage data or network misinformation. When the system determines that there is a problem, it generates an alarm.

Systems, devices, methods and techniques that enable users to dynamically adjust and adapt transmission power reception margins, power spectral densities and the like to changing DSL environmental and operating situations would represent a significant advance in the field of DSL operations. Furthermore, monitoring and evaluating the performance, headroom, etc., used in the DSL environment and in service, by an independent entity, can and would support, direct and (in some cases) control the activities and devices of users represent a significant advance in DSL operations.

It is now the object of the invention to propose a method for a controller and a corresponding controller for a digital subscriber line modem pair with which or with which an adjustment of parameters, such as transmission power, power-spectral density, etc., is made possible in changing DSL situations; Furthermore, a monitoring and evaluation of performance, reception latitude, etc., in particular with the help of an independent unit, should be made possible in order to support the subscriber modems.

Accordingly, the invention provides a control method or a controller as defined in the independent claims. Advantageous embodiments and developments are specified in the dependent claims.

In particular, a method is thus proposed in which operating data of the DSL modem pair, namely current and historical operating data, are collected, after which at least part of the collected operating data is analyzed and a parameter set related to the reception margin is generated on the basis of the analyzed operating data; the pair of modems are then instructed to operate in accordance with this generated set of parameters.

In a corresponding manner, a control or a controller for monitoring several pairs of modems for digital subscriber lines (DSL) is provided, which has a collecting module for collecting current and historical operating data from at least one DSL modem pair, an analysis module connected to the collecting module for analyzing at least part of the collected operating data and a with has instruction signal generation module connected to the analysis module, which is set up, to generate a reception margin-related parameter set on the basis of this analysis in order to instruct a DSL modem pair or several DSL modem pairs to operate in accordance with this generated parameter set.

The invention can be used in connection with ADSL1, ADSL2, ADSL2 + and VDSL systems as well as other types of DSL systems.

The controller can be a DSM center, an intelligent modem and / or a computer system. The controller and / or other components can be a computer-implemented device or a combination of devices. In some embodiments

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AT 13 387 U2 2013-11-15, the control is in a location far away from the modem. In other cases, the controller may reside in the same location with either or both of the modems as equipment directly attached to a modem, creating an intelligent modem.

The reception margin-related parameter value can be a PSD-related value, such as the MAXNOMPSD or MAXNOMATP parameter, which is used by various ADSL systems. In some embodiments, the margin related parameter value may be a shaped spectral mask for use in transmissions and / or may represent upper bounds or thresholds in bit overlay for frequencies used in transmissions between the modems. In some cases, preference bands can be imposed to direct modems to favor and / or avoid certain frequencies.

The operating data may include one or more modem operating parameters that are the same as or different from the reception margin related parameter, the value of which is regulated by the controller. The historical data can be kept in a database. The operational data can also include data collected by the DSL system in which the modem pair operates, for example from one or more MIBs or other data sources. The operating data can be sent to the controller through a communication medium, internally and / or externally of the DSL system itself. Some other types of operational data that can be evaluated include data relating to crosstalk between the modem pair and neighboring DSL lines, a history of the reception margin previously used by the modem pair, relearning counts (which indicate that the MAXSNRM is too low can be set when relearn counts are high), transmit power levels previously used by the modem pair, data rates, previously used by the modem pair and / or obtaining data relating to a previous failure of the modem pair.

Further details and advantages of the invention will become apparent from the following detailed description and the accompanying drawings.

The invention will be more readily understood from the following detailed description in conjunction with the accompanying drawings, in which like reference characters designate like structural elements; show it:

Figure 1

Figure 2

3 shows the reference model system according to the G.997.1 standard in a schematic block diagram;

is a schematic block diagram showing a general, exemplary DSL installation;

Figure 3 is a schematic block diagram of one embodiment in a DSL system using a controller such as a DSM center;

4A, 4B and 4C comparative representations of performance-adaptive, rate-adaptive and reception margin-adaptive implementations of DSL systems;

Figure 5A

Figure 5B

Figure 6A

Figure 6B

Figure 7 is a flow and schematic diagram showing the operation of an ADSL1 system according to an embodiment of the invention;

Fig. 3 is a flow and schematic diagram showing the operation of an ADSL1 system according to an embodiment of the invention;

Fig. 3 is a flow and schematic diagram showing the operation of an ADSL2 system according to an embodiment of the invention;

Fig. 3 is a flow and schematic diagram showing the operation of an ADSL2 system according to an embodiment of the invention;

a flow chart showing a method according to an embodiment of the invention;

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Fig

[0059] FIG

Fig

Figure 2 is a block diagram of a typical computer system suitable for implementing embodiments of the invention;

a pair of bit-loading energy tables;

an example of a reception margin distribution for a particular data rate estimated on the basis of collected operational data;

a method according to an embodiment of the invention that uses the estimated distribution of one or more performance-related parameters such as reception margin; and one embodiment of the invention showing an intelligent modem unit with a controller that has a processor and memory integrated with a DSL modern.

In general, embodiments of the invention are described below in connection with the operation of a DSL system with a controller (e.g. a computer system, an intelligent modem, a dynamic spectrum manager, a spectrum management center (SMC) and / or a dynamic spectrum management center (DSM center - Dynamic Spectrum Management Center) as described in publications and other documents pertaining to the field, or any other suitable control device and / or unit, including a computer system). When the term control is used herein, it is intended to refer to any or all of these or other suitable control means. A controller can be a single unit or combination of components that is a computer-implemented system, device, or combination of devices that perform the functions described below.

As will be apparent to one skilled in the art after reading the present specification, embodiments of the invention can be adapted to work in various DSL and other communication systems known to those skilled in the art. A dynamic spectrum manager or other controller using a communication system using one or more embodiments of the invention may be a service provider and / or operator (which in some cases may be a CLEC, ILEC, or other service provider) or may be one Be a party that is partially or fully independent of the system operator (s).

If several parameters are monitored and are adjustable in a communication system and are not set statically, the performance can generally be improved, often dramatically (for example higher data rates can be achieved, more users can be served, less power can be consumed, etc.) . That is, if system settings are adjusted adaptively as a function of line or channel performance, adaptive changes to system operation can improve data rates and other services to users. For example, there is currently no system for dynamic monitoring of a large number of parameters, key figures etc. and support for operators and users in optimizing DSL services. Some operators have developed rudimentary forms of collecting DSL line data and have attempted to either:

Increase the data rate available after an initial service installation until a well-functioning, acceptable rate is observed (referred to as provisioning); and or

Observe a line bit error rate over time to determine if it needs to be redeployed at a lower data rate.

In particular, the rules for increasing or decreasing data rates are in these

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Systems often overly simplified, fixed functions of one or very few input parameters. Systems according to embodiments of the invention that accept and analyze multiple inputs and essentially become dynamic functions of some parameters based on the observation and processing of the many other observed parameters and the line's performance history represent a significant improvement in this area.

To reduce performance problems of various types, including crosstalk interference, many communication systems limit the power used by transmitters sending data in a particular system. The margin of a transmission system is the level of transmission power (usually expressed in dB) versus the minimum power required to achieve a desired performance (e.g. a threshold bit error rate or BER of the system). The basic goal is to use sufficient power to correct and / or compensate for noise-induced errors and interference-induced errors, while minimizing the power required for transmission to reduce the potential problems caused by excessive levels the transmission power. In many cases, however, equipment manufacturers, system operators, and others use such excessive power (resulting in excessive reception margins) in an effort to provide high data rates and to find an easier strategy for dealing with potential problems such as crosstalk.

The invention uses information about line properties (e.g., operational data) to more carefully evaluate acceptable problem / interference avoidance and data rates in performance adaptive systems and methodologies. This is done by analyzing the information and / or operational data available and then training and setting modems to operate at power transmission levels (and hence margins) that provide sufficient performance for acceptable data transmission while minimizing the adverse effects that can occur can have a line of one user on lines of other users. In particular, embodiments of the present invention may generate headroom-related parameters and direct at least one modem in a modem pair to use one or more such headway-related parameters to assist the modem pair in meeting a particular headroom goal.

Figure 1 shows a reference model system with which embodiments of the present invention can be used in accordance with the G.997.1 standard (also known as G.ploam), which is well known to those skilled in the art. This model applies to all ADSL systems that meet the various standards that may or may not contain subdivisions, such as ADSL1 (G.992.1), ADSL-Lite (G.992.2), ADSL2 (G.992.3), ADSL2-Lite G. .992.4, ADSL2 + (G.992.5) and the VDSL standards derived from G.993.x, as well as the G.991.1 and G.991.2 SHDSL standards, all with or without bonding. This model is well known to those skilled in the art.

The G.997.1 standard specifies the management of the physical layer for ADSL transmission systems on the basis of the clear, embedded operational channel (EOC), as defined in G.997.1, and the use of indicator bits and EOC messages as defined in G.992.X standards. In addition, G.997.1 specifies the content of network management elements for configuration, error and performance management. In performing these functions, the system uses a range of operational data (including performance data) available at an access node (AN).

In FIG. 1, a user terminal 110 (sometimes also referred to as customer premises equipment or CPE) is coupled to a home network 112, which in turn is coupled to a network termination unit (NT) 120. The NT 120 contains an ATU-R 122 (for example a transceiver which is defined by one of the ADSL standards) or another suitable network termination modem, a

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AT 13 387 U2 2013-11-15 another transceiver or another communication unit. The NT 120 also includes a Management Entity (ME) 124. The ME 124 may be any suitable hardware device, such as a microprocessor, microcontroller, or circuit state machine in firmware or hardware capable of operation is required by applicable standards and / or other criteria. The ME 124 collects and stores, among other things, operational data in its MIB, which is a database of information maintained by each ME and accessible through network management protocols such as SNMP (Simple Network Management Protocol), a management protocol used to collect information from a network device, to be sent to an administrator console / program or via TL1 commands, TL1 being a long established command language used for programming responses and commands between telecommunication network elements.

Each ATU-R in a system is coupled to an ATU-C in a CO or other central location. In FIG. 1, the ATU-C 142 is located at an access node (AN) 140 in a CO 146. An ME 144 also maintains an MIB of operating data belonging to the ATU-C 142. The AN 140 may be coupled to a broadband network 170 or other network as would be apparent to those skilled in the art. The ATU-R 122 and ATU-C 142 are coupled to one another by a loop 130 which, in the case of ADSL, is usually a twisted pair telephone that also carries other communication services.

Several of the interfaces shown in FIG. 1 are used to determine and collect operating data. The Q interface 155 provides the interface between the network management system (NMS) 150 of the operator and the ME 144 in the AN 140. All parameters that are specified in the G.997.1 standard apply to the Q interface 155. The near-end parameters supported in the ME 144 are derived from the ATUC 142, while the far-end parameters from the ATU-R 122 can be derived from one of the two interfaces via the U interface. Indicator bits and EOC messages sent using an embedded channel 132 and provided at the PMD level can be used in the ME 144 to generate the required ATU-R 122 parameters. However, the operations, administration and maintenance (OAM) channel and a suitable protocol for obtaining the parameters from the ATU-R 122 can also be used if these are requested by the ME 144. The far-end parameters of the ATU-C 142 can also be derived from one of two interfaces via the U interface. Indicator bits and EOC messages provided at the PMD level can be used to generate the required ATU-C 142 parameters in the ME 122 of the NT 120. However, the OAM channel and a suitable protocol can also be used to obtain the parameters from the ATU-C 142 if these are requested by the ME 124.

On the U-interface (which is essentially the loop 130) there are two management interfaces, one on the ATU-C 142 (the UC interface 157) and one on the ATU-R 122 (the UR interface 158) . The UC interface 157 supplies ATU-C near-end parameters for the ATU-R 122, which are obtained via the UR interface 130. The U-R interface 158 also supplies ATU-R near-end parameters for the ATU-C 142, which are obtained via the U interface 130. The applicable parameters can depend on the transmitter / receiver standard used (e.g. BG992.1 or G.992.2). The G.997.1 standard specifies an optional OAM communication channel over the U-interface 130. When this channel is implemented, ATU-C and ATU-R pairs can use it for the transport of OAM messages on the physical layer. Thus, the transceivers 122, 142 of such a system share various operational data held in their respective MIBs.

As will be apparent to those skilled in the art, at least some of the parameters described in these documents can be used in connection with embodiments of the invention. Furthermore, at least some of the system descriptions are also in embodiments / 54

<img file="AT13387U2_D0011.tif" />

AT 13 387 U2 2013-11-15 of the invention applicable. Various types of operational data available from a DSL NMS can be found in it; others may be known to those skilled in the art.

In a typical topology of a DSL system in which a number of transmitter-receiver pairs operate and / or are available, a part of each subscriber loop with the loops of other users is in a multiple pair connection (or a bundle) merged. After the base, very close to the Consumer Equipment (CPE), the loop takes the form of a drop wire (lead-in line) and emerges from the bundle. Therefore, the subscriber loop crosses two different environments. Part of the loop can be inside the link, where the loop is sometimes shielded from external electromagnetic interference but is subject to crosstalk. After the socket, the drop wire is often not affected by crosstalk because it is far from other active pairs for most of the drop, but transmission can also be more significantly affected by electromagnetic interference because the drop wires are not are shielded. Many drop wires have 2 to 8 twisted pairs in them, and in multiple service situations in a home or when bonding (multiplexing and demultiplexing a single service) these lines, there may be additional substantial crosstalk between these lines in the drop segment.

A general, exemplary DSL installation scenario in which embodiments of the invention can be used is shown in FIG. All subscriber loops from a total of (L + M) users 291,292 go through at least one common connection. Although the loops in Figure 2 are shown to be approximately the same length, it is more likely that the loops of a particular system will be of different lengths and, in some cases, very different lengths. Each user is connected to a central office 210, 220 by a dedicated line. However, each subscriber loop can run through different environments and media. In FIG. 2, L users 291 are connected to the CO 210 with a combination of optical fiber 213 and twisted copper pairs 217, which is generally referred to as fiber to the cabinet (FTTCab) or fiber to the curb (glass fiber is routed to the cable distributor). For signals from the transceiver 211 in the CO 210, their signals from the optical line connection 212 and optical network connection 215 in the CO 210 and the optical network unit (ONU) 218, which can also be referred to as a remote terminal (RT) , transformed. Modems 216 in ONU 218 serve as transceivers for signals between ONU 218 and users 291.

The loops 227 of the remaining M users 292 are only twisted copper pairs, a scenario that is referred to as Fiber to the Exchange (FTTEx). If possible and economically practical, FTTCab is preferable to FTTEx, as this reduces the length of the copper part of the subscriber loop and thus increases the achievable rates. The presence of FTTCab loops can cause problems with FTT Ex-Schi eiten. FTTCab is also expected to become an increasingly popular topology in the future. This type of topology can lead to significant crosstalk interference and can mean that the lines of the different users have different data transport and performance capacities due to the specific environment in which they operate. The topology can be such that fiber optic cable distributor lines and exchange lines can be mixed in the same connection. Users L + 1 to L + M could be a remote connection (instead of a CO) and users 1 to L could be even closer to customers, possibly being served by a line connection or another connection supplied with fiber optics (hence two connections supplied with fiber optics of which one is closer to the customer than the other).

As can be seen in FIG. 2, the lines from the CO 220 to the users 292 share the connection 222, which is not used by the lines between the CO 210 and the users 291. Furthermore, a different connection 240 is common to all lines to / from CO 210 and CO 220 and their respective users 291,292.

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AT 13 387 U2 2013-11-15

According to one embodiment shown in FIG. 3, a reception margin and performance analyzer 300 may be part of an independent unit that monitors a DSL system as controller 310 (for example, a dynamic spectrum manager or dynamic spectrum management center), the user and / or supports one or more system operators or providers in optimizing or otherwise controlling their use of the system. (A dynamic spectrum manager can also be referred to as a dynamic spectrum management center, DSM center, system maintenance center, or SMC). In some embodiments, the controller 310 may be operated by an ILEC or CLEC that operates DSL lines from a CO or other location. In other embodiments, such as the example in Fig. 12, an intelligent modem unit 1200 has a controller 800 '(including, for example, a processor and memory) that is integrated with a modem 1210 at a user site, central office, or other individual site. As can be seen by dashed line 346 in FIG. 3, the controller 310 can be in or part of the CO 146, or can be external to and independent of the CO 146 and any party operating in the system. Furthermore, the controller 310 can be connected to and / or control multiple COs. Likewise, components of the controller 310 may or may not be in the same location and / or in the same device and / or may instead be accessible to the controller in different locations.

In the exemplary system of FIG. 3, the analysis device 300 includes collection means 320 (which can also perform monitoring if desired) and analysis means 340. As can be seen in FIG. 3, the collection and / or monitoring means 320 can be at sources in the DSL system, such as the NMS 150, ME 144, connected to the AN 140 and / or the MIB 148, which is managed by the ME 144, and collect data through and from them. The data can also be collected from external sources by means 320 over the broadband network 170 (e.g., via the TCP / IP protocol or other means outside of the normal internal data communication systems in a particular DSL system). For example, the controller can collect operational data from an ATU-R over the internet or even an ATU-C over the internet if the EMS is hostile or bandwidth is limited. Operational data can also be collected from the service provider's NMS, which itself can collect from various sources.

The analysis means 340 and / or monitoring / collection means 320 may also be coupled to a source 345 of received margin performance or history, such as a database or memory, which may or may not be part of the analyzer 300 or controller 310. One or more of the analyzer connections enable analyzer 300 to collect operational data. The data can be collected once (for example, during a single transceiver training session) or over time. In some cases, monitor 320 collects data on a periodic basis, although it may collect data on demand or on some other non-periodic basis so that analyzer 300 can update its user and line data as desired.

The analysis means 340 can analyze supplied data to determine whether instructions need to be sent to one or more modems in order to assist the modems in achieving a certain reception margin target. The analysis means 340 of the analysis device 300 is coupled to an instruction signal generation means 350 in the controller 310. A signal generator 350 is configured to accept a reception margin-related parameter value generated by the analysis means 340 for use by a modem, the reception margin-related parameter value being based on the operating data and calculated to be at least one modem in the fulfillment of a Receiving margin target and instruction signals (for example a requested or required MAXNOMPSD value, sends a PSDMASK setting or other instructions such as CARMASK, MAXSNRM, MINSNRM, TSNRM, MAXNOMATP, MAXRXPWR or any rate-adaptive reception margins or timers) to users in the communication system (for example ADSL transceivers such as ATU-Cs). How through that

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<img file="AT13387U2_D0013.tif" />

AT 13 387 U2 2013-11-15 indicated by dashed line 347, the instruction signal generating means 350 may or may not be part of the analyzer 300 and / or may be implemented in the same hardware as a computer system. The command signal generator 350 provides a means for regulating one or more reception margin related parameter values ​​in the modem pair.

As will be apparent to those skilled in the art, if the controller is a fully independent entity (ie, not owned and / or operated by the company that owns and / or operates lines in the CO), much of the configuration can and operating information of the DSL system may not be available. Even in cases where a CLEC or ILEC is operating and / or acting as controller 310, much of this data may be unknown. Various techniques can be used to estimate the data and / or information required. An example of such techniques can be found in U.S. Application No. 10 / 817,128.

In some embodiments, the analysis device 300 can be implemented in a computer such as a PC, a workstation or the like (an example of this is disclosed in connection with FIG. 8). The collecting means 320, analyzing means 340 and / or instruction signal generating means 350 can be software modules, hardware modules or a combination of both, as is obvious to one skilled in the art. For example, these components can all reside in the same computer system or can reside in different devices. Databases can be introduced to manage large numbers of lines and used to manage the volume of data generated by the lines and the controller.

The configuration of Figure 3 can be used to implement power adaptive systems and methods in accordance with embodiments of the present invention. As can be seen in Figure 4A, power adaptive systems, such as those included in the present invention, reduce and / or minimize power consumption while maintaining a target data rate (e.g., a minimum data rate) and a target noise reception margin. Rate adaptive systems and methods illustrated in Figure 4B use all of the available power (the total transmit PSD, usually at a fixed level) to maximize the data rate while maintaining the target receive margin level. Reception margin adaptive systems and methods as shown in Fig. 4C also use all of the available power, in this case to maximize the reception margin while maintaining a fixed data rate. The actual installation of an ADSL usually follows the headroom adaptive techniques of Figure 4C, often to the detriment of users and operators. Once excess power is used, either to unnecessarily increase the data rate or to provide an excessive level of reception headroom, crosstalk and other problems can arise for users and operators. Unlike the excessive power systems, power adaptive techniques such as those of the present invention offer reliable data rates, minimal power consumption and sufficient reception margin to guarantee reliable error and interference avoidance.

The ADSL field operation has taught that modems, while often claiming compliance with a plethora of emerging, volatile DSL standards, often all of the different quantities, rules and guidelines in different ways for different manufacturers (and indeed for different ones Generations and versions of hardware and software from the same manufacturer). Furthermore, various interoperability tests, including those currently about to be released, do not adequately address all of the various possible configurations and performance levels, leaving a great deal of uncertainty about actual field conditions. Using the present invention, a controller provides and enforces consistent operating policies and implementations to decrease, increase, and / or maintain power and / or PSD levels to avoid problems such as excessive crosstalk between modems. Furthermore, the controller can experiment with various settings normally made by or during the expected operation of the standard Kon14 / 54

<img file="AT13387U2_D0014.tif" />

AT 13 387 U2 2013-11-15 form products are not set up to determine cause / effect and time variation of DSL environments, so that combinations of rate / performance / price offers for a DSL service to customers in connections with different degrees of crosstalk and a Customer topology can generate maximum service and / or maximum return.

Time variation information and techniques correspond to ADSL2 modes known as dynamic rate adjustment. The specific parameters in G.997.1 for this are known as RAUSNRMus / ds and RA-DSNRMus / ds (rate adaptive up / down signal-to-noise ratio reception margin, uplink or downlink) and enable a setting of a reception margin target that must be achieved before the rate can be increased or decreased. RA-USNRMus is a level with which the calculated reception margin of the modem is compared. If this calculated reception margin exceeds USNRMus for a period of RA-UTIME or longer, the data rate can be increased without relearning in the ADSL2. After the rate increase, the reception margin is smaller than before the rate increase. If the calculated reception margin is now less than USNRMus, the modem's calculated reception margin is compared to RA-DSNRMus, and if it is greater than this value, the modem stays at the same data rate. If the reception margin is below RA-DSNRMus now or at any time for a period of time which exceeds RADTIMEus, the modem data rate is reduced until the reception margin again exceeds RA-DSNRMus. There is always a maximum rate at which the rate adaptation stops and then MAXSNRM applies here. The reception margin targets must be maintained for a period of time which is specified by the DSM center via another control parameter RA-UTIMEus / ds or RADTIMEus / ds (rate adaptive up / down time, upstream or downstream).

In general, as shown in the example of FIG. 7, the controller collects operational data (usually relating to the DSL modem pair of interest) at 710. The operating data can include the historical reception margin performance of the DSL system, historical performance data (such as previously measured and known reception margin levels for the modem pair and other performance-related information), current performance data relating to the DSL Modern, relearning count data, other data relating to a Refer to the modem learning process, or contain error data.

Data can be collected using the internal communication system (s) and / or using external communication (e.g. the Internet). The operational data could include information regarding one or more modem operational parameter values ​​used or set by the modem pair collected at 720.

At 730, the controller analyzes the operational data to determine which receive margin related parameter values ​​could assist the modem pair in meeting a receive margin goal or otherwise improve the performance of the modem pair. The controller can then generate a receive margin related parameter value at 740. The receiving margin related parameter value may be for a modem operating parameter that the controller has taken into account, or it may be another receiving margin related parameter. At 750, the controller generates an instruction signal representing the margin related parameter value and sends it to at least one modem in the modem pair, instructing the modem pair to accept the margin related parameter value for use in training or normal operation, depending on the circumstances.

The controller can update the operation of the modem pair more than once by performing such an analysis, as shown by the dotted arrow in FIG. 7, or can only do this at certain times, such as immediately before the modem training. As will be discussed in detail below, the parameters with which the controller works and operating data that are available to the controller vary depending on

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<img file="AT13387U2_D0015.tif" />

AT 13 387 U2 2013-11-15 on the type of DSL system in which the modem pair works. Again, the modem operating parameter (s) used by the controller in the analysis of the modem reception margin performance may or may not be the same parameters as those for which the reception margin related parameter value is generated and sent to the modem. Although the embodiments of the present invention are not limited to such types, they are useful in supporting modems using ADSL1, ADSL2, ADSL2 +, and / or VDSL. Using the controller can help ensure standards-compliant modems remain compliant. Furthermore, embodiments of the present invention can be used to boost the performance of one or more DSL lines, taking into account operational data such as crosstalk effects and other information that may have a detrimental effect on DSL performance.

The basic idea is that the spectrum level, power, spectrum shape, etc. can all be changed depending on the reported reception margin / distribution. In other words, after evaluating data on the previous performance of a modem pair and knowing one or more parameters of the modem pair related to the reception range, a controller or the like can be used. Encourage or force the modem pair to adopt operational values ​​that assist the modems in meeting one or more reception margin goals, whether or not required by a standard.

In some embodiments of the present invention, a controller coupled to the ATU-C side of a modem pair dynamically controls the receive margin settings and adjustments for each line (e.g. in an ADSL2 system by setting and / or changing the MAXSNRM Parameter, by imposing a different MAXNOMPSD level or by setting the PSDMASK in an ADSL2 + modem or by combinations of some or all of these or some of the others, previously mentioned parameters such as CARMASK, MAXSNRM, TSNRM, MINSNRM, RA reception margins / timers). Such dynamic reception margin adjustment by applying a deeper mask is not part of any standard. Even those attempting to comply with the reception margin and performance rules may be limited by the range of PCBs allowed or may be limited by lack of information history from previous training and line usage (possibly with other modems and / or other customers, that were previously at the end of the line). Thus, in another embodiment, the controller may determine from a history of reported receive margin measurements that the line is exceeding a desired receive margin target and thereby apply a lower PSD level during or prior to training through the mechanisms discussed above. This was not done in previous systems because users and operators did not really know the anticipated power level and did not want to unnecessarily weaken a modem should it experience a high level of noise during operation. Likewise, if for some reason a modem is not using sufficient power and / or receiving headroom and is experiencing excessive noise and error problems, the controller can instruct the modem to use a higher PSD level during the learning process or operation for better operation make possible.

As stated above, in some systems it may be preferred to use a historical, previously measured, and / or known reception margin to seed the training process so that an appropriate performance degradation is implemented during the training process. The controller may maintain or have access to a performance history so that the controller can continuously improve estimates and decisions as to which PSD or other reception margin-related parameters to use to instruct the modem when the modem is reset or relearned (whichever, as required , forced or recommended). For example, a service provider or controller may wait until the line is inactive - for example, count the ATM cells or other customer information measures to determine whether the line is active or not - and then reset to use the newer one (s) PSD (s) in

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<img file="AT13387U2_D0016.tif" />

AT 13 387 U2 2013-11-15 in a way that is completely transparent to a user. In other situations, the service provider can simply relearn at a time when the system is unlikely to be in use (for example, in the middle of the night). In some embodiments, the controller may use this historical information that tells the one or both modems in the modem pair (e.g., the ATU-C) which initial PSD level should be used so that an available PCB value or any other setting (for example, a -14.5 dBm decrease from the ATU-R) has a chance of meeting the reception headroom specification.

In some embodiments, programming is based on either prior use or training. The previous usage may be more important in some cases. A second pass through the training process, which can also be used, is essentially a quick solution for the modem vendors themselves, especially for downstream transmission at the DSLAM vendors, with the modems essentially stopping the current training process and then starting the training process Being able to start over a second time with a different, lower NOMPSD, which means that the reception margin is then smaller than MAXSNRM.

Some embodiments of the present invention incorporate adherence to the ADDNMR limit by initializing the PSDMASK setting using prior knowledge. Optimal spectrum management (OSM), which is known to those skilled in the art, has been investigated and has some gains from level-2 coordinated spectrum management by a dynamic spectrum manager, a DSM center or other control over already large gains from theoretical iterative water filling which was dealt with in previous systems. Level 2 means that a controller such as a DSM center can jointly coordinate the spectrum levels (for example on the basis of a perceived crosstalk between two or more lines). Level 1 means that the spectrum is adjusted based only on observations from the same one line. Level 0 means no possibility for a DSM. More information about OSM can be found in various papers to the T1E1.4 Working Group of ANSI, including papers T1E1.4 / 2003/325, T1E 1.4 / 2004/459 and TIE 1.4 / 2004/460.

However, the central coordination necessary for an OSM makes it difficult to achieve the gains in a practical system because the spectra must be centrally controlled. In embodiments of the present invention, the use of the PSDMASK from G.997.1 for the newly appearing DSM report from ANSI T1E1.4 and probably for VDSL2 enables the usual separate integer water filling to achieve essentially comparable performances as OSM by simply adding some flat PSD masks can be set up in different segments of the frequencies used by a DSL modern. The levels of these bands can be increased or decreased until a desired combination of data rates is achieved among users who continue to proceed with bit swapping or bit loading in the normal manner while observing the particular PSDMASK constraints imposed on each tone are valid. Reported reception margins can correspond to worst case reception margins and MAXSNRM is usually only applied to the tone with the smallest reception margin. Manufacturers could not use the best loading or bit change algorithms, which leads to variations and interpretations of the applied PSDMASK. Thus, a preferred band (or PREFBAND) bit or a reference to the EM of a modem pair can be sent to inform them that a separate water-filling application or an approximation to this is desired and that the MAXSNRM parameters apply to the reception margins that should be found for all tones (and not just the worst tone). This PREFBAND notice is part of this invention.

As stated above, for ADSL1 systems, the MAXNOMPSD value is usually set by the operator. However, using an embodiment of the present invention, an example of which is shown in Figure 5A, a controller 510 sees one

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<img file="AT13387U2_D0017.tif" />

AT 13 387 U2 2013-11-15 reception margin-related parameter value (for example a MAXNOMPSD value) for the ATU-C 530. The controller 510 can send instructions or otherwise communicate with the system using the NMS and / or element management system, which can accept the MAXNOMPSD or PSDMASK values ​​from the controller 510. The instruction signal (e.g. from the instruction signal generating means 350) can be sent to the ATU-C 530 via the NMS, element management system, email, ftp, or in any suitable manner as will be apparent to those skilled in the art. The controller may also provide a MAXNOMATP value in addition to or in place of the MAXNOMPSD value (es) in some embodiments. In some cases, the ADSL1 CARMASK procedure (a simple on / off indicator for each tone that is standardized and allowed for an operator specification in ADSL1) can be used instead of or in addition to MAXNOMATP / PSD to switch off carriers in a band that create excessive crosstalk in other DSL systems.

In embodiments of the present invention applicable to ADSL1, the controller 510 calculates a reception margin related parameter value used by modems (e.g., the MAXNOMPSD value) based on operational data collected by the controller ( e.g. data from a MIB 525 or a historical data module 520) for a transmitter-receiver training, which leads to a suitable reception margin during the SHOW-TIME operation. (NOMPSD is chosen by the sender and not a MIB controlled setting; but NOMPSD must be less than MAXNOMPSD and the field practice for this sender is to set the NOMPSD at the same level as a MAXNOMPSD if that value can be implemented. Some MAXNOMPSDs, e.g. -40 dBm / Hz delivered to an RT that can only implement -44 dBm / Hz can actually be higher than the NOMPSD). History / library 520 receives data from operator MiB 525 and any other available sources of relevant data on system performance. The controller 510 forwards the MAXNOMPSD value or some other receive margin related parameter value to the ATU-C 530. The MAXNOMPSD value provided by the controller can be calculated so that the system realizes the TSNRM / TARSNRM reception margin value, the MAXSNRM reception margin value, a reception margin value between the two, or any other desired reception margin target. The controller may decide to test or project line performance under a number of different types of noise situations that have occurred, are currently occurring, or may be occurring, particularly to simulate situations where other adjacent lines also have programmed PSDs.

Since modem 510 often uses MAXNOMPSD as its NOMPSD value, the new MAXNOMPSD value provided by controller 510 will likely become the NOMPSD value used by ATU-C modem 530. Even if the MAXNOMPSD value supplied by the controller is not selected as the NOMPSD value by the ATU-C, the NOMPSD value cannot be higher than the supplied MAXNOMPSD value and there will still be excessive reception margins during normal SHOWTIME operation avoided.

The control thereby enforces an upper limit value for the NOMPSD, even if the control cannot enforce the NOMPSD value directly. Therefore, if -52 is the desired NOMPSD value, the controller sets MAXNOMPSD to -52. Since NOMPSD cannot be higher than MAXNOMPSD, setting MAXNOMPSD to -52 limits the value of NOMPSD, which in turn limits the level of any resulting reception margin and avoids excessive reception margin utilization. Usually MAXNOMPSD is the NOMPSD in the very first transceiver training section of ADSL1 training, although this is up to the seller, and the controller can thus indirectly enforce the NOMPSD value used by the ATU-C.

As can be seen in Fig. 5A, after the ATU-C 530 has received its MAXNOMPSD value (and reset if necessary), it uses its control-induced or control-influenced NOMPSD to measure the upstream power over 18/54

<img file="AT13387U2_D0018.tif" />

AT 13 387 U2 2013-11-15 transmission from the ATU-R 540 and thus for estimating the loop length. Based on this estimate, the ATU-C 530 calculates its PCB performance degradation, if any (for example in accordance with Appendix A of the ADSL1 standard) and informs the ATU-R 540 of this value, setting REFPSD = NOMPSD - PCB, as in step 550 shown in Figure 5A. Using embodiments of the present invention, the PCB value is less likely to cause non-compliance with receive margin requirements due to consideration and use of historical data 520 maintained by controller 510 regarding the line on which modems 530, 540 operate.

The ATU-R 540 then calculates the reception margin, bits (b,) and gains (g,) after the transceiver learning process and the channel analysis using the REFPSD value. The values ​​of g ,, which are permitted under ADSL1 are -14.5 dB to +2.5 dB. As can be seen in step 560 of Figure 5A, the final PSD value for tone i is PSD, = NOMPSD - PCB + g, which is subject to the MAXNOMPSD constraint initially imposed by the controller 510. (In some embodiments of the present invention, the g-values ​​can be the reception margin related parameter values ​​and can be indirectly controlled by the controller via an instruction signal from the controller to a receiver telling it to decrease gains). Therefore, if NOMPSD equals MAXNOMPSD, the PCB is 2 dB, and g, for a large group of adjacent tones is +2.5 dB, with the final PSD values ​​for all of these tones being limited to MAXNOMPSD on average by the MAXNOMPSD constraint, even if the calculated PSD would be 0.5 dB above MAXNOMPSD (although this is unlikely given the analysis of historical data and the controller's choice of MAXNOMPSD due to previous operating characteristics). In theory, this could apply to any tone. However, ADSL1 allows MAXNOMPSD to be exceeded by up to 2.5 dB on individual tones, but MAXNOMPSD must be met over a group of tones on average. In all cases where the combination of PCB and g, is not positive, the PSD, - value is at or below NOMPSD.

In this way, the controller-driven NOMPSD seeds this entire process, thereby enabling the controller 510 to reconcile the eventual receive margin and any excessive receive margin with the MIB-provided MAXSNRM levels specified in the ADSL1 standard (or any other imposed limit value) are defined. Finally, settings can still be made during SHOWTIME, whereby the gain change capacities of ADSL1 are used.

There is no MIB parameter that directly tells the controller 510 what the NOMPSD value is in ADSL1. The controller can base its recommendation / instruction on a training sequence that has just been completed (with the modem pair going directly into a relearn procedure) or other historical data to which the controller has access.

For an upward power reduction, as shown in the example of Figure 5B, the ATU-R 540 begins sending a test signal to the ATU-C 53 0 at a PSD value selected in advance, for example -38 dBm / Hz. The ATU-C 530 measures the line attenuation and estimates the loop length and sends this information back to the ATU-R 540. The ATU-C 530 also calculates the reception headroom, bits and gains for its own operation. The second transmission of the ATU-R 540 is still at its original PSD value. After receiving a second transmission from the ATU-R 540, the ATU-C 530 calculates its gains and can command a drop in power of up to 14.5 dB, so an initial PSD value of -38 is used by the ATU-R 540, and then the final PSD of the ATU-R 540 is between -52.5 and -38.

While the upward and downward training / degradation are separate events, one embodiment of the invention lowers the upward PSD under the control of the controller when the previous reception margin is high. Upstream crosstalk is generally not bad in DSL, but the high power signal upstream can cause a stronger echo that is found in downlink signals in user modems

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AT 13 387 U2 2013-11-15 leaked. By reducing this echo with the lower, non-standard, uplink PSD, the downlink power can be increased by several dB (possibly up to 10 dB) when one echo dominates another noise, as is sometimes the case with bridged taps available. When using this embodiment, a modem performs better than current modems on long loops, where this local echo in the user modem seems to be the dominant, area-limiting effect most often.

Once the modems enter the SHOWTIME, further adjustments to gains can be made using a gain change.

In ADSL1 and other systems, a simple option in accordance with an embodiment of the present invention is to measure the reception margin immediately before the SHOWTIME. If the measured reception margin just before the modems enter the SHOWTIME is higher than a prescribed limit (a MAXSNRM of 16 dB for example), training is started again and the modems relearn in a second pass, using the permitted reduction values become. Such an implementation could in most situations not be controlled by the DSM center and could instead be carried out in an owner mode in the modems themselves, e.g. B. by a method according to an embodiment of the present invention in a software module or the like.

Embodiments of the present invention, which are implemented under the ADSL2 standard, examples of which are shown in Figures 6A and 6B, again use a controller 610, the process of an initialization, a handshake, a channel discovery, a transceiver -Training process, can initiate a channel analysis and an exchange using one or more reception margin-related parameter values ​​provided by the controller for the modems.

Due to the range of available PCB values ​​(0, 1, ..., 40 dB) and the fact that either the ATU-R or ATU-C can command a reduction, ADSL2 has a mechanism that has a wider range a power reduction that can be used to instruct the transmitter to reduce the initial PSD when consistently high reception margins have been previously observed. The value of the PCB of the transmitter can be calculated starting with the MAXNOMPSD parameter that the controller supplies. Embodiments of the present invention thus use an earlier history to aid in setting the MAXNOMPSD and / or the PCB / tssi through proprietary levels lower than -60 dBm / Hz PSDs.

As noted above, the transmitter may decrease one PCB if directed to do so by a DSM center, operator, or other controller. In the ADSL2, the transmitters can impose a PCB because the modems must use the larger of the two PCBs requested by the transmitter and receiver. Usually compliance with an operator-supplied MAXNOMPSD would have occurred and the NOMPSD could already be below -40 dBm / Hz before the PCB is used early in the learning process. The actual NOMPSD value transmitted in one of the very first messages sent between the sender and receiver in a section known as the G.hs section of the ADSL2 learning process appears before a notification from the PCB. Then the downstream transmitter can impose a more substantial PCB for several reasons (for example, if upstream signals look so large that the transmitter wants to ensure that MAXSNRM is adhered to, or because the transmitter has ordered the operator to PCB through a proprietary mode of the manufacturer use). However, the external MIB for very low PSD values ​​is not in the ADSL2 standard (MAXNOMPSD&gt; -60 in ADSL2).

Using the present invention, an adjustment of up to 40 dB may be necessary due to previously reported high line reception margins or line history. The transmitter can enable the controller (e.g. a DSM center)

<img file="AT13387U2_D0020.tif" />

AT 13 387 U2 2013-11-15 it is necessary to specify that the transmitter wants a PSD lower than -60 dBm / Hz (which is basically not required in the ADSL2 standard). MAXNOMPSD cannot be less than -60 dBm / Hz in ADSL2, so that a controller (e.g. a DSM center or operator) can demand an additional reduction through the PCB or the tssi parameters. The tssi parameters are available in the ADSL2, but cannot be specified by a controller or an operator in the ADSL2 (only the modem manufacturer can set the tssi in the ADSL2). (ADSL2 + does not allow tssi to be specified by the operator using the PSDMASK MIB parameters. In the ADSL2 +, a controller, operator or DSM center can force tssi values ​​using the so-called PSDMASK MIB parameters. The PSDMASK-MIB parameter is not available in the ADSL2 and the manufacturer can instead set a tssi value if he so wishes). In summary, the PCB is actually under the control of the transmitter. The controller (for example the DSM center or the operator) can specify the PCB indirectly via a very small setting for the transmission of the PSD if the ADSL2 modem gives the operator or DSM center a setting of a PSD below -60 in a proprietary mode enables. (Some ADSL1 DSLAMS have a software update that goes beyond the G.992.1 standard and allows the MAXNOMPSD value to be set to -80 dBm / Hz by a controller / DSM center. In principle, the line only looks longer at the ATU-R, which is not aware that this has been done, but is still working well. Otherwise, the PCB can instead be set in conformity with the standard with tssi in ADSL2 + via PSDMASK, which is specified in ADSL2 + MB).

Only in the upstream direction can the PCB, which is sent from the receiver (ATU-C) to the transmitter, also be required that the upstream received power is less than a value known as MAXRXPWR, which is determined by the operator or the controller (for example a DSM center) can be set in ADSL2. Thus, the controller using MAXRXPWR can cause the PCB to be implemented through an instruction from the DSM center or the like. However, the downstream position requires the use of proprietary functions to force less than -60 (with either PCB or tssi).

The present invention includes either setting the level with tssi or implementing a DSM intelligent transmitter that bypasses the need for control commands and initially sets the PSD level with PCB or both.

In Figures 6A and 6B, the ADSL2 standard enables a receiving modem to command a power reduction (PCB) by 0, 1, 2, ..., 40 dB as part of a training session. These additional, available maximum 40 dB are not available in ADSL1 transmission systems. The sender can also decide to lower the power and tell the receiver that it has done so so that each modem can specify the PCB value. Of particular importance is the fact that the ATU-R can do this for a downlink transmission and the ATU-C for an uplink transmission.

In the example of Figure 6A, the controller 510 begins by providing a receive margin related parameter value (for example a MAXNOMPSD value) with the modem pair (for example by sending the same to a single modem such as the ATU-C 630) in step 645 . The ADSL2 and 'G.ploam (G.997.1) standards also allow performance to be limited externally by an operator or controller (such as a DSM center) as specified by a MAXNOMATP parameter which has an effect similar to the MAXNOMPSD Parameters could have. According to ADSL2, NOMPSD must be between -60 and -40 for each tone i for which CARMASK is 1, which allows selective use of frequencies within the usable band or bands. As with ADSL1, the NOMPSD value is usually set to MAXNOMPSD to allow the use of a maximum allowable reception margin.

The controller 510 can consult a receiving margin performance history 520 (such as a library, database, memory, or computer module), which can obtain its information from any suitable source, for example a system estimate / 54

<img file="AT13387U2_D0021.tif" />

AT 13 387 U2 2013-11-15 or the MIB 525, which in turn receives its data from the ATU-C 630, from one or more administrative units 544 or from another source, as is obvious to the person skilled in the art. Using collected operating data and possibly one or more modem operating parameters, the controller 510 may analyze the operating data and then generate one or more receiving margin related parameter values ​​and send the modified receiving margin related parameter value (s) to the modem pair for implementation. The reception margin-related parameter (here for example the MAXNOMPSD value that is sent to the ATU-C 630) is selected and calculated in such a way that it leads to a suitable reception margin level after a transmitter-receiver training prior to operation, etc. Assist modem in meeting one or more reception latitude goals.

The ATU-C 630 sends the initial NOMPSD value during the handshake phase of the training according to §8.13.2 of the ADSL2 standard to the ATU-R 640. During the channel discovery phase 650 of the pre-operational training, both the ATU-C 630 and measure ATU-R 640 the line power and suggest a PCB value. The largest PCB value (ie the greatest decrease in performance) is assumed by the modem pair 630, 640, which establishes a REFPSD for each frequency used, where REFPSD = NOMPSD - PCB, meaning that the lowest of the two REFPSD values ​​received by the two modems ( Sender and receiver) are proposed is used. In the ADSL2, the NOMPSD level can be set by the operator or the controller 610 (such as a DSM center) to any level between -60 dBm / Hz and -38 dBm / Hz in 0.1 dB steps. A REFPSD level of only -100 dBm / Hz could thus arise if the ADSL2 receiver MAXSNR correctly observes and commands a necessarily large PCB value. This of course assumes that the modem manufacturer has correctly implemented the PCB for MAXSNRM, but often this parameter is neither correctly implemented nor is it tested and measured in existing modem interoperability / conformance tests.

During transceiver training 655 and channel analysis 660, the system adjusts its equalizers and echo cancellers and measures the SNR in both the downward and upward directions. The final stage before SHOWTIME is the exchange in step 665. During this final pre-operational phase, the ATU-R can command a further power setting in the range of -14.5 and + 2.5 + EXTGI. The system then goes into its normal SHOWTIME mode, in which MAXSNRM is observed and adhered to and in which further settings can be made using permissible gain changes.

In ADSL2, nominally the same gain values ​​from -14.5 dB to +2.5 dB that are permissible for the steady state are used as are found in ADSL1. In ADSL2, however, the reinterpretation of a sync symbol power level at the same level as data symbols allows this full -14.5dB to +2.5dB range of gains to be performed, while ADSL1 modems are usually within +2.5dB or -2 , 5 dB of the initial power level offset of -40, -42, ... or -52 from the initial levels of the training gains g, are limited during the change. The ADSL2-EXTGI parameter enables the gains to be increased above 2.5 dB up to +18.0 dB in addition to the levels that are nominally used when switching to ADSL2. EXTGI is determined and / or set by the DSLAM manufacturer outside the influence of an operator, a controller and / or a dynamic spectrum manager and is transmitted to the reception modem during initialization. A high EXTGI value can confuse different PSD levels, as neither the MAXNOMPSD nor the PSDMASK (ADSL2 +) should be exceeded, even if this EXTGI is sufficiently large. Some manufacturers might ignore the mask and implement mask-ignoring EXTGI due to the confused intentions specified by a large EXTGI value and decreased masks (although the ADSL2 standard does not allow this).

Some current modems and / or systems periodically fail to use correct settings, and the MAXSNRM limit often cannot in ADSL2 modems

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AT 13 387 U2 2013-11-15 must be implemented correctly. Thus, by providing a MAXNOMPSD defined by the controller, the sender ATU-C side can impose a PCB (and / or tssi in ADSL2) value while an initialization message transports the downstream PCB value, effectively forcing the reception margin to decrease by an amount equal to the proposed downstream PCB (and based on an earlier history of receive margin observation). In particular, in one or more embodiments of the present invention, the controller 510 may pass a MAXNOMPSD level to the ATU-C 630 that is intentionally below -60 dBm / Hz to force deeper receive margins and bring them closer to the commanded MAXSNRM or the commanded MAXSNRM (possibly based on a history of receiving margin activity, which a single training of the line would not indicate to the PCB-determining algorithm of the receiver modem).

In addition, when the PCB values ​​are swapped, the exact level of power degradation necessary to meet MAXSNRM may not be known, which means that the PCB values ​​may then be too conservative. Thus, again in ADSL2 it may be necessary for controller 510 to observe and / or query the reception margin history 520 and to impose a lower PSD on the line than the MAXNOMPSD of -52 for ADSL1 or -60 for ADSL2. This would then be observed by the modems through the PCB to the REFPSD = NOMPSD - PCB &lt;MAXNOMPSD used. Furthermore, ADSL2 and the complementary G.997.1 standard enable a DSL system operator or a controller to impose a MAXNOMPSD parameter that reduces the REFPSD level to only -60 dBm / Hz or down to -38 dBm / Hz (depending on the applicable appendix, some of which only allow -40).

In some cases, the MAXNOMPSD (effectively the NOMPSD) could be set up to 34 dBm / Hz (which is non-standard). The controller can instruct a DSLAM to use very long lines in these cases, where the current -40 dBm Hz would only have caused 12 or 13 dBm or similar of a transmission power to be used (the long lines with low reception margins and low data rates are the only ones that really need full power). The actual PSD, which is lower than this -60 dBm / Hz, has to be specified by a PSDMASK parameter which is only observed as a MIB control parameter in the ADSL2 +. However, the controller can notify a participating ATU-C or ATU-R to warn this unit itself in the ADSL2 in a standard-compliant manner to use a PCB (or tssi) value that further reduces the -60dBm / Hz. The MAXNOMPSD parameter is routed to both sides of the DSL line before the ADSL learning process initiates a procedure known as a handshake (according to ITU Standard G.994.1). The PSDMASK parameter is only MIB specified in ADSL2 + (it is transported in ADSL2, but at the discretion of the sender and not controlled or specified by the operator), but can be conveyed in other ways (for example by file transfer programs (ftp) or a simple e-mail message via the Internet to an agreed IP address between the controller and the ATU-C or ATU-R).

One skilled in the art will find that the ADSL2 + standard has all of the ADSL2 capabilities specified above, up to doubling the spectrum or doubling the number of DMT tones used. Thus, degradation comments and capabilities discussed in connection with ADSL2 systems also apply to ADSL2 + systems. Additionally, some embodiments of the present invention relating to ADSL2 + use a concept known as Spectrum Toolbox that enables an operator and / or controller to use a potentially non-flat initial PSDMASK quantity that includes multiple flat spectrum regions specified a number of cutoff frequencies and power levels. The PSDMASK can range from as little as -96 dBm / Hz to -32 dBm / Hz. This ability has sometimes been ignored, misunderstood, or destroyed by transmission systems, to the detriment of such systems. By using a previous history of a line, a controller can use some of the ADSL2 + capabilities to implement embodiments of the present invention.

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In ADSL2 + up to 32 stop points (about 8 bands) are allowed, but the mechanism for their transmission in the G.994.1 initialization actually allows ADSL2 +, if desired, a PSDMASK level specification for all 512 downward and all 64 upward Sounds. Thus, a controller such as a DSM center or operator can upgrade or downgrade different bands by imposing a PSDMASK, starting with the beginning of the training and continuing through all further training and SHOWTIME BitA / reinforcement changes. PCB can still be used, but becomes more of a receiver mechanism for the implementation of MAXSNRM, since PSDMASK essentially replaces MAXNOMPSD from ADSL2 (although this parameter is still present and a PSDMASK cannot exceed it). The equivalent of PSDMASK is also upward permitted under G.992.5, with the exception that it must be implemented by direct specification of the upward tssi parameters (while the downward link is either a direct specification of tssi or the lighter direct specification the PSDMASK enables). The PREFBAND bit of the DSM report is in addition to G.992.5 and addresses the additional ambiguity of the PSDMASK when observing MAXSNRM - that is, the reception margin calculation in G.992.5 with bit caps (which are at the limit value for Example 15 or less, but a finite value) is usually defined as the worst reception margin over all tones. Thus, the loading algorithm could increase the reception margin in a preferred (i.e., good or used) frequency band to a very high level, while the reception margin is limited to a smaller value in a less preferred band with lower PSD. Since the worst reception margin then occurs in the least preferred band, this is reported and then essentially prevents the application of the MAXSNRM principle. If instead the PREFBAND is active, this means that all reception margins of tones must be smaller than MAXSNRM, not just the worst. Thus, the receiver cannot misunderstand the intent of the PSDMASK, whether it is being used for band preference or for some other reason. The imposing of the PSDMASK is then indicated to the modems by the operator with PREFBAND ON. The EIN indication essentially prevents the seller's proprietary charging procedures from thwarting the intent of preferential band treatment that is intended by imposing the PSDMASK with PREFBAND turned on.

For example, in the downlink, the ATU-R loading algorithm could see that the reception margin on one tone is anywhere in the 7 dB band and all others are 30 dB or more. Since this is the worst reception margin, the modem then demands compliance with the reception margin target MAXSNRM. However, PSDMASK is set in such a way that no reception margin for a tone exceeds MAXSNRM. PREFBAND ON means the modem manufacturer must implement all of this compliance and be able to display 7dB not just on one tone and 30 anywhere else - they must observe MAXSNRM on all tones while PREFBAND is ON.

Typically, low levels are used in PSDMASK to specify bands that should be avoided and / or little used. A flat, low PSDMASK &lt;60 dBm / Hz specified by the operator / DSM center, however, forces the NOMPSD to this specified level (which can be as little as 96 dBm / Hz) in the invention, whereby a consequently equally low level above the low initial NOMPSD level Reception margin is enforced (even before the modems used PCB to do the same). This very low PSD is invoked or enforced by the controller, operator, or DSM center as specified, thereby anticipating that some manufacturer modems might do a poor job of receiving margin and spectrum management, even when standards call for better management. Together with the available NMS communication, a controller can pass the PSDMASK as the reception margin-related parameter value to the modems via the Internet (for example e-mail and / or ftp communication). Since the PSDMASK did not get to the modems via the element management system, the modems would then have to make settings with PCB and / or g (within (-14.5) to (EXTGI + 2.5) limits) to the REFPSD value .

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AT 13 387 U2 2013-11-15

Thus, as an example of a DSL line that allows EXTGI of 18 dB and a lowest MAXNOMPSD of -60 dBm / Hz required in the standards, the ATUR could use the PSD in a band that is -58 dBm / Hz is initialized by setting g to -14.5 dB in this band set to -72.5 dBm / Hz. The same ATU-R could also set a PSD of -40 dBm / Hz in another band by setting g i = +18 dB in that other band. The resulting band preference would then be 32.5 dB (the difference between the two levels). It should be noted that this is done without direct use of the PSDMASK in the element management system MIB, but the recipient who implements a loading is informed of the PSDMASK or the degree of band preference via the Internet, who then knows how to use the full g-range, to meet the range even if no initial PSDMASK-PSD setting was allowed. Thus, an intelligent ATU-R essentially forces a standards-compliant ADSL2 ATU-C modem (where no PSDMASK is used) to implement a band preference. This would use the entire available g-range, so of course tssi, if available, is a better implementation. However, like in ADSL2, Tssi might not always be available. If, on the other hand, the PSDMASK works in the MIB of an ADSL2 + modem, this procedure would not be necessary and tssi could be used instead.

Some manufacturers allow an external specification of the MAXNOMPSD up to -80 in their new ADSL1 and ADSL2 software in recognition that this is a (slightly) non-standard operating mode, but which does not really do any harm, other than the fact that the operator then knows how to set certain parameters like Hlog and Attenuation calculated on the basis of -52 (or -60).

In the VDSL there is a reference noise uplink PSD (referred to herein as REFNOISE) that can be used to bring the PSDs to certain settings. In some embodiments of the present invention, control works backwards from an initial REFNOISE value to an implied PSDMASK as a modified receive margin related parameter value. Thus, with some translations and unconventional use of the Ref-Noise PSD, the present invention can be used in connection with the VDSL system and can achieve the same effects as in the ADSLs.

Band preference is important to achieve gains in the OSM and can be defined as the emphasis of a band in an uncoordinated loading that continues the usual bit and gain swap procedures necessary in practical systems without loss of performance. A dynamic spectrum manager cannot be expected to react fast enough and switch bit distributions and it would certainly be slower than the modem reactions themselves, which is one of the reasons that OSM proponents are in favor of water filling or approximations taken by Modems performed in a distributed fashion (sometimes referred to as iterative water-filling) are good enough. The band preference essentially tells the receiving modem to watch a PSDMASK in a band defined by the PSDMASK or the tss parameter of the ADSL2 + G.992.5 Spectral Toolbox as the reception margin related parameter value in order to give preference, thereby creating a Priority is generally possible for some tapes in water filling and loading is prevented to levels that could interfere with other DSLs. The theoretical water filling procedure solves the equations:

E._n = - σ \ = constant n = 1, ..., NSC equation (1) for non-negative energies E._n on each of the tones (NSC is the maximum number of tones). The gap Γ is a constant that is determined by code selection and the desired reception margins at a certain bit error rate in DSLs. The channel attenuation on each frequency is given by | H_n|² is specified and the noise energy at each tone is given by σ² specified, both of which will be measured during training (or it will be their ratio directly

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<img file="AT13387U2_D0025.tif" />

AT 13 387 U2 2013-11-15) and updated during SHOWTIME operation. This procedure is considered to be continuous in time with updates at periodic intervals or change intervals on the channel.

This theoretical water-filling procedure is well known in DSL and can be approximated in numerous ways, including various greedy algorithms (also known as Levin-Campello procedures) for single integer bit constraints where consecutive bits are at the the least energy-consuming bit positions are applied to all tones, until the desired maximum bit rate limit is reached with no more than a maximum specified receive margin (often known as MAXSNRM in various DSL standards) and no less than a minimum or target receive margin (often known as TARSNRM or TSNRM in various DSL standards) . A frequency-dependent bit cap and a frequency-dependent TSNRM [n] for expanding existing systems are then transmitted via ftp and / or e-mail to the receiving modem, which implements the loading algorithm. These can also be useful when FEC cannot be adaptive and the system is forced to provide frequency dependent protection from discontinuous / impulse noise that does not occur frequently but is large when it does and the range of frequencies it encounters is known.

Impact algorithms calculate the number of bits b [n] for each tone and the g, gain (g_n) Factor for each tone. There are many variants of loading algorithms that are well known to those skilled in the art. At any specified data rate (or maximum data rate, if rate adaptive), the modem vendor can attempt to minimize approximately the amount of power required by a particular MAXSNRM. If the reception margin is less than MAXSNRM, but the spectrum generated and reported seems to be different, a controller such as a DSM center can propose a PSD mask to be observed when changing bits and applying in the invention.

An enactment procedure is provided herein for use with embodiments of the present invention. The loading depends essentially on two vector quantities: a vector of incrementally normalized energies, the components of which are A (b); and a channel related noise vector or channel normalized mean square errors (MSEs) v_n. The latter size v_n can be calculated as

MSE [n] MSE '[n]

<img file="AT13387U2_D0026.tif" />

Equation (2) where W_n is the frequency domain equalizer (FEQ) coefficient on tone n when an FEQ is used. The energy to send another bit on tone n when tone n is already b_n Bits carries is

AE_n(b_n + 1) = A (b_n + 1) - v_n Equation (3) where the function A (b) does not depend on the tone index n, but on the ADSL constellations and the target reception margin TSNRM. The function A (b) defines the incremental (additional) energy that is necessary to transmit the b-th bit on any channel, where v_n = 1 in relation to the (b - l)^te Bit is. Thus, by storing this function A (b), which requires up to BCAP digits (never more than 15 in ADSL, so that Δ (16) = °° and Δ (0) = 0), and by calculating / updating and storing of the NSC channel-dependent variables v_n, n = 1, ..., NSC, the additional energy for sending the additional energy on a channel can be calculated by the product of the two functions as in equation (3).

After computing equation (3), the total energy obtained on the tone must be compared to any applicable MAXNOMPSD or PSDMASK constraint, and if that limit is greater than 2.5 dB (or some other precision-based number that the designer is in favor of less than 2.5 dB), then ΔΕ applies_η (b_n + 1) = °° (that is, the incremental energy is reset to a maximum number that is in

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AT 13 387 U2 2013-11-15 the loading implemented by the processor can be displayed). Such PSDMASK restrictions can often be imposed in ADSL systems. Storing such masks usually requires an additional 1 (MAXNOMPSD only) to about 20 digits (PSDMASK level for different tones in ADSL2 +). Table 1 of FIG. 9 lists the incremental energies A (b) and the total energies for the case that no PSDMASK is reached, and again v_n = 1 if no trellis codes are used for the constellations of G.992.1 / 3/5 ADSL (ADSL1 does not allow b = 1, so the value of Δ (2) is the first of interest on any tone n in ADSL1 is). The quantity ε is a normalized reference energy which is calculated as ε_{= 1} q0.95 + tsnrm-codgain equation (4) where CODGAIN = 3.8 + 3J-b_ave dB is for the use of FEC only, and is about 3.8 dB nominally for coding gain plus an additional 6% parity bits (so an offset is given with respect to a system that has an overall data rate as a reference, and this reference so treated as having no parity or code).

The ba_V.e-value is the average (estimated) number of bits per tone obtained from an estimate of the total conduction rate by dividing the total number of bits per symbol (BMAX) by the number of tones and then multiplying the result by the premium percentage and then the nominal 3 dB / bit effort can be calculated. Usually this CODGAIN value is around 5 dB. This additional gain of over 3.8 dB is necessary because a line bit rate is applied by the algorithm described here.

The parity surcharge size \ -] &lt;0.08 for this rule to work. The rule becomes optiVNistic if more parity is used, and the CODGAIN value should not exceed 5 dB in the line bit rate loading. The limit of 5 dB can reduce the calculated line bit rate-total bit BMAX (i.e. the real coding gain can still be higher than 8 dB, but not as high as the formula indicates), but when a large parity fraction is used , the line is dominated by impulsive or discontinuous noise and pessimistic coding is advisable.

When chronic lines use larger parity fractions, the CODGAIN (gain) is usually higher, but no stationary noise dominates the performance and so underestimating the coding gain is not a serious error on chronic lines.

In ADSL1, the tones are rearranged for a coder progression from tones with the lowest number of bits to the highest number of bits. Instead, ADSL2 enables the receiver to rearrange the tones for a transmitter coder progression according to the tone reordering desired and specified by the receiver. This tone rearrangement is transmitted to the transmitter during the learning process. In ADSL2 and ADSL2 + this reordering can be used to simplify exposure search algorithms, but embodiments of the invention assume that it has been implemented in the relevant standardized manner and does not address the exact transceiver ordering used. The reference loading algorithm provided herein is applicable to any specified ranking.

An example of a reference training application algorithm follows:

Adding each bit in turn to the tone that has a minimum AE_n(b_n +1) has, over all tones, until one of two stop criteria is met:

(1) the maximum network rate has been reached; or

(2) the total permissible energy has been exceeded.

If criterion (1) is met, the energy for all tones can be up to the ratio of

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PSDMASK (or MAXNOMPSD), which is applicable at any frequency. The smallest such increase in dB plus TSNRM is the current reported SNRM. If the smallest such increase is such that TSNRM plus increase exceeds MAXSNRM, then the energy of all tones should instead be increased by MAXSNRM-TSNRM dB.

The following is an example of a reference SHOWTIME application algorithm:

At the current data rate, search for the tone that has a minimum AE_n(b_n +1) has, over all tones and saving the tone index n. Search again for the tone that has a maximum AE_m(b_m) has, and storing the index m. Change of a bit from tone m to tone n, if and only if AE_n(b_n + I) &lt;AE_m(b_m).

The total energy can be maintained if the reception margin for the new bit distribution does not exceed MAXSNRM. If MAXSNRM has now been exceeded on this tone and this is the tone with minimal reception margin, then the energy on all tones should be reduced by the factor by which the reception margin of the tone n MAXSNRM exceeds.

The ADSL1 and ADSL2 standards have a bit changing mechanism that enables a bit to change from tone m to tone n.

At the end of each procedure, the total energy on each tone is calculated by τ = ΣΜ (0 = E_n(b "-1) + ΔΕ_η(b_n) Equation (5) z = l

This energy level can result in a gain level g_n as will be apparent to those skilled in the art.

A trellis coding means a somewhat higher complexity when applying, but follows the same basic principle. The application of a trellis coding to the DMT transmission system forms sub-channel groups of two tones each. The two tones within a group are consecutive tones in the order that was used. There is always an even number of tones used and thus an integer number of groups if trellis coding is used in ADSL. The incremental energy tables then become the incremental energy for adding a trellis-encoded bit to a group (and not just a tone) of two tones. Up to 29 bits can be assigned in a group (15 for the first tone plus 15 for the second tone minus an additional bit which is required in the trellis coding) if BCAP = 15 for all tones.

Within a group of two tones it can be assumed without loss of generality that v_n+ i&gt; v_n (Otherwise only re-indexing is to be carried out in the loading algorithm for the calculation and the re-indexing is to be canceled when the loading algorithm is exited). The incremental energy for adding a bit to a group is then always the smallest energy for adding this bit within the two tones, knowing that if a group starts with 0 bits, the first added information bit is actually two bits is (an additional first bit for adding a bit / group in the trellis coding), which were added to tone n. Each subsequent added bit costs only one incremental energy unit instead of the two incremental energy units for the first bit. The loading tables are those shown in Table 2 of FIG.

Thus, in the investigation of the group of tones (n n + 1) for each bit after the first, added to tone n, the application algorithm adds possibly the bit to the single tone with group, n \ group, n +1) = min (v "· Δ (ά" + l), v_{H + 1} · Δ (ά "₊₁ +1)) n, n + \

Equation (6)

To clear a bit, the 4D examines the trellis loading algorithm instead of 28/54

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AT 13 387 U2 2013-11-15 of which

AE group, n) group, n \ group, n ^:max (v "n, n + l ^A.(bn \ vn + r^Δ(δ "+ ι))

Equation (7)

If only trellis coding is used, the CODGAIN in equation (4) should be 4.2 + 1.5 = 5.7 dB. If both trellis and FEC are used, the CODGAIN should be 5.5 + 1.5 + 3 · | - | b_ave which can be estimated at around 8 dB. The same applies here

J &lt;0.08 for this rule to work. The rule becomes optimistic when more parity is used, and the CODGAIN should not exceed 8 dB in the line bit rate overlay. The 8 dB limit may exceed the calculated line bit rate-total bits BMAX, but if a large parity fraction is used, impulse or discontinuous noise dominates the line and pessimistic coding gain is advisable.

The implementation of the application algorithm can lead to a jagged or sawtooth-like energy characteristic due to the jumps in the energy, since there are only integer bits per tone. Thus, one reason for adjusting the gain is to equalize the reception margin on all tones. Usually this is a minor effect, but it can provide slightly more modem / line reception headroom - it does not need to be implemented and is often not implemented by the modem manufacturer. Once a bit distribution is set, some tones may have a slightly higher reception margin than others (the reported reception margin is the worst of all tones). In fact, the tone to which a next bit is added when another bit is to be loaded has the highest reception margin, the next, other tone thereafter the next highest reception margin, and so on. Reinforcements on these tones with higher reception margins than the last tone that receives a bit when applied could transmit a slightly lower energy overall and the tone with the last applied bit could transmit more (as long as the PSD mask is not violated).

ADSL1 and ADSL2 both allow the gain to be specified in the range of [-14.5, + 2.5 + EXTGI] dB during training (where EXTGI = 0 always applies to ADSL1). ADSL2 allows the same area during SHOWTIME operation, and the exact g_nValue is sent through the overhead channel. ADSL1 limits the range during SHOWTIME to -2, -1, 1.2 or 3 dB changes relative to the value that was last set during training or during a previous gain change, in particular the exact precision value of the gain after a gain change of / 7 // 77 / (512.-IO '' '' '²⁰, where around means an adjustment to the nearest whole value. Cascading gain changes should not cause a violation of the range [-14.5, + 2.5 + EXTGI].

Modem vendors should know that ADSL1 modems have a synch symbol that does not degrade in performance every 17 ms. Thus, if the rest of the signal is reduced in power by an application procedure (such as a gain change in particular), the intersymbol interference (ISI) from the ADSL1 synch symbol can appear relatively large and dominate all other noise. This ISI can be deleted in many ways including, since the synch symbol is known, by effectively redesigning the ISI and removing it. Another solution is to change the time domain equalization settings as the gap between synch symbol energy and normal symbol energy increases. The ADSL1 standard recommends, but does not require, that the SHOWTIME gain changes keep the total symbol energy at ± 2.5 dB of the established SynchSymbol power spectral density levels.

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For ADSL1, the basic loading step can be followed by a reception margin equalization step. This receive margin equalization step occurs after a data rate has been set (with either the desired rate being achieved in a fixed rate ADSL or being set to a maximum rate in the rate adaptive ADSL).

The algorithm listed here can be used for an ADSL1 reception margin equalization during the SHOWTIME (ADSL1 gain change) and assumes for a SHOWTIME gain change that gains have already been set during training so that the MAXSNRM is not exceeded (if MAXSNRM is exceeded during the initial teach-in process, no gain change is necessary). For a fixed rate application, the energy used is less than the total allowable energy (or the modem will be retrained or possibly operate at &lt;TSNRM, in which case this procedure can and should be used, with TSNRM being retrained to the current lower SNRM is set). The calculation of the reception margin for each tone is well known to those skilled in the art. The steps are:

1. Sequence of the tones in the sense of SNRM [n] from smallest to largest (and remembering the sequence) and storage of MAXS = max SNRM [n] &lt;MAXSNRM.

n

2. Increase each following tone by 1 dB up to the index m, where SNR [m]&gt; MAXS, as long as the total energy (or PSDMASK / MAXNOMPSD) is not exceeded, and then reset MAXS min (SNRM [m] + 1, MAXSNRM) dB. For those tones that would have exceeded the PSDMASK / MAXNOMPSD, remove them from further considerations.

3. Re-ranking the tones again as in step 1 (maintaining the ranking)

4. Repeat step 2 for newly ranked tones. 5. Repeat step 3

6. Repeat step 4

7. Removal of the entire sequence and renewed insertion of all tones that would have previously exceeded PSDMASK / MAXNOMPSD.

All gain changes are then implemented. By the end of this procedure, up to 3 dB will have been added to those tones that had the lowest reception margins. The bit distribution has not changed, but the reception margins may have increased by 1, 2 or 3 dB on some tones. The new minimum reception margin is no less than that before the procedure was carried out and is usually 1 dB or better.

The same procedure as the ADSL1 SHOWTIME follows for ADSL1 reception headroom equalization during initialization (and ADSL2 gain change for training or SHOWTIME), except that the designer can use an increment smaller than 1 dB, for example 0.5 dB so that the algorithm can run up to 5 passes (instead of 3), with each pass potentially providing an additional 0.5 dB on an increasingly smaller subset of tones. Here too, if MAXSNRM has been exceeded (only ADSL1) or reached (ADSL1 or ADSL2), no gain change is necessary.

In all of the changeover methods, a first bit change and then again a gain change can of course be carried out, since the channel noise (MSE) changes over time. Even if no bit change is necessary, a gain change may be necessary if the MSE has changed.

The algorithms discussed above are slightly modified for BCAP [n] and TSNRM [n]. For a non-uniform BCAP [n] &lt;15 then A (b_n) = °° for b_n &gt; BCAP [n] before multiplying A (b_n) with V_n being tested to AE_n(b_n) to obtain. With the Trellis30 / 54

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AT 13 387 U2 2013-11-15

Coding applies BCAP [n] for information bits, so that, as in Table 2 of FIG. 9, the last entry corresponds to ΔΕ_η (BCAP [n]) = °° in the column for v_n is, while ΔΕ_{η +}ι {BCAP [n +1] + 1) = °° for the column for v_n+ i is.

For the non-uniform TSNRM [n] it is according to

TSNRM [n]

TSNRM

Equation (8) simpler (less memory), every v_n instead of changing Δφ), where TSNRM is the single (uniform) reception margin that is specified (usually 6 dB). Both BCAP [n] and TSNRM [n] can be used for various improvements on specific lines.

In greedy algorithms, tones that have already been subjected to a maximum bit cap have an infinite (high) effort to add additional bits, thereby avoiding bits / tones that exceed the bit cap. The present invention recognizes that tones for which adding a bit would cause the defined PSDMASK to be exceeded should also have infinite (high) cost in these positions, which may or may not be implemented by different manufacturers. Changes in the channel and / or noise are monitored and the algorithms run continuously, allowing the DMT transmitter to move bits around to maintain good energy usage and reception margin. The infinite overhead associated with exceeding an imposed spectral mask is maintained in SHOWTIME mode, so that bits are not reassigned to a PSDMASK-limited band, even if this band were more attractive than other bands with a theoretical water-filling.

The PSDMASK's imposition of an essentially infinite cost of adding bits on a particular tone when the existing energy of that tone is already at or near the mask level is used in the band preference. In essence, adding a bit in a non-preferred band is not too cumbersome because of the PSDMASK constraint, which affects or forces the individual water-filling algorithm (i.e., the greedy algorithm) to apply the same bit in a preferred band where the PSDMAS K can be higher, thus promoting loading of more bits. The PSDMASK can thus be set well below the permissible MAXNOMPSD mask in some bands in order to indicate a preference for the use of other bands, presumably because the control and / or the dynamic spectrum manager (also here, for example, an SMC or DSM center or manager) determined that such a band preference is valuable to the lines. Centralized control of bit distribution is likely to be impractical because of the speed of response required to change the bit distribution required or appropriate for time-varying channel effects (such as changes in crosstalk, etc.). Instead, the band preference is specified at the time of initialization by the controller and / or the dynamic spectrum manager; presumably through a deliberate choice of the PSDMASK levels (or possibly through tsSn levels), which are specified in ADSL2 + and are currently being proposed for VDSL2.

The energy on a particular tone, E_n, is determined by 3 components as follows:

^E.n = E, n-gn-tSS^£n

Equation (9) where E₀,_n is the REFPSD level. For example, an ADSL modem without a power reset and without using a PSDMASK would have an energy E₀,_nthat is -40 dBm / Hz (or any other value set forth in the various appendices of standards or designated by a controller in accordance with an embodiment of the present invention as NOMPSD / 54

<img file="AT13387U2_D0032.tif" />

AT 13 387 U2 2013-11-15) that would be known to both the sender and the recipient. The size g?

specifies a g gain calculated by the receiver, which is usually between -14.5 dB and +2.5 dB for ADSL standards and could theoretically be any non-negative (linear) value. This gain is fed to the transmitter through a control reverse channel in DMT DSL either when the initialization is exchanged or during the bit change in the live mode of the modem. The to? Parameter is defined by the MIB for each use of the modem and can be between 0 and 1. In theoretical water filling, the tss parameter is almost useless as the gain parameter could cancel any tss effect and adjust the energy levels to the desired water filling levels (if gains g_n would not have an upper limit). Of course, a tss = O value would prevent the use of the tone and could not be reversed. In practice, the upper limit of the possible gain selections by 2.5 dB or by EXTGI allows the tss to affect the limit values ​​of the application algorithm and is thus a useful tool. In particular, an upper limit of the gain at +2.5 dB prevents a significant reversal (if this limit is increased by EXTGI, greater reversal is possible and a value of EXTGI = 18.0 dB could perhaps inadvertently reintroduce the band preference reversal of a theoretical water -Fillings lead). The unmodified WaterFilling procedure would restore a band by a positive gain value when tss is low. The situation when E_O + 2.5 dB is maximum in equation (1) above, corresponds directly to an infinite (high in finite precision) effort associated with adding an extra bit to this tone in a single application. This non-linearity of a single application is important to the band preference.

In a system where PSDMASK values ​​were intentionally set lower in an otherwise good band, the infinite effort associated with applying multiple bits beyond those levels that reach the mask in that band forces the application algorithm to do so to instead set bits in other available transmission bands that have not yet reached the PSDMASK PSD limit value, these other bands are then essentially preferred or favored. This can essentially also be done with the non-standard BCAP [n] concept (the variable bit capping frequency). For example, in certain ADSL CO / RT mixed situations and VDSL upstream examples, the theoretical water filling is ineffective as it tries to continue with the application in the lower frequency band, which looks more attractive (but is then limited by the crosstalk that the second User is generated on the longer line). For the same situations, if the receiver also knows the PSD-MASK setting, a single water filling would cover the infinite effort for exceeding the PSDMASK, if it is set at the appropriate low level in order to prevent crosstalk into the longer line ( or if bit caps are kept at a certain number of maximum bits, which is less than the usual 15). Thus, the single water filling would then start with adding bits to the second higher frequency band on the shorter line in both examples and achieve the same results as OSM. Significant improvements can be achieved if the dynamic spectrum manager knows that certain lines are mutual interferers (for example using one of the estimation methods of the invention described above).

In some embodiments, PREFBAND is a 1-bit unsigned integer for which 1 specifies that the effort to charge bits above the PSDMASK should be infinite (or effectively forbidden) and that MAXSNRM on all tones and not just that Sound with the worst reception margin should be applied. It will be apparent to those skilled in the art that this embodiment of the invention could also be effectively used in VDSL2. The determination of the imposed PSDMASK levels is the domain of a controller such as a DSM center. For the control it might be necessary to know the Hlog and noise power spectrum density centrally as well as the Xlog amplifications of the DSM report so that it can centrally determine good PSDMASK levels that are in the band preference

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AT 13 387 U2 2013-11-15. One method for such a determination that avoids the high computational and convergence problems of OSM is to try to determine some gross spectrum levels and band edge frequencies in a simulated iterative single water-filling of all channels using the Hlog, Xlog and noise power spectral densities which settings will give an acceptable line performance improvement.

OSM algorithms, and to a lesser extent band preference, require at least a knowledge of the crosstalk transfer functions between interfering lines. In an ADSL2 system or in any system (e-mail / ftp) where all relevant connection insertion losses and crosstalk-insertion loss transfer functions are available to or can be calculated by the controller, a central algorithm can determine the levels to be used in the Band preference can be used. These levels are then transmitted to the ATU-C and / or ATU-R and implemented by the PSDMASKs and / or the band preference bit.

Measurements such as forward error correction and a bit error rate in DSL systems are intended to help the DSL service to reliably provide high data rates for DSL customers. While both reliability (in some cases fewer relearns, reduced possibility of throughput degradation due to high code violation (CV) counts, etc. as high data rates are important, there is no clear way of finding a compromise for these two, and service providers often come up with a mixture of unreliable lines (i.e., for example, frequent retraining, high CV numbers) and low-performance lines (low data rates). Operators have also found that these reliability and service / performance issues add to repair vulnerabilities and expense (e.g., upgrades) and to customer satisfaction and loyalty, including customer sales. Embodiments of the present invention include methods and techniques for achieving desired data rates with minimal reception headroom or maximizing desired data rates while maintaining one or more minimal reliability conditions. That is, using embodiments of the present invention where the maximum data rate (for good lines) can be maintained, adaptive power / receive headroom controls can be used to optimize performance. If the maximum data rate cannot be achieved (on bad lines), adaptive data rate controls can be implemented in order to implement the best possible data rate, which is based on one or more performance-related parameters and / or goals (e.g. CV number, Relearning processes, etc.) is compliant.

In current systems and standards, the data rate is selected by the modem during training (or sometimes in the SHOWTIME in ADSL2) when the dynamic rate adaptation is ON. This selected data rate cannot exceed the maximum rate for which the customer pays and is therefore fixed on good lines at this maximum rate. For bad lines, the rate is less than the maximum and is used for a certain reception margin level (e.g. 6th dB reception margin) selected during training. In other words, adaptive data rate control only applies when a line cannot reach the maximum rate in the customer's roster (e.g. 1.5-3 Mbps).

If the maximum data rate can be reliably achieved with an appropriate reception margin, there is no need to adaptively control the data rate (the maximum rate is simply chosen) and instead control of the reception margin is to avoid excess levels (while maintaining the maximum rate becomes) the subject. In such cases, the receive margin target for performance degradation may need to be determined adaptively for each line so that a desired performance parameter and / or target (e.g. retraining / CV criteria) for the line can be met during the interference to other lines is minimized. For example, for a line that does not experience fluctuation in noise power, a reception margin target of 6 dB might be sufficient. However, for a line that experiences a noise power fluctuation of up to 10 dB, a suitable reception margin to be selected could be 16 dB. So far, however, has been a

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AT 13 387 U2 2013-11-15 specified reception margin target at the time of training was used and only the noise power at the time of training was chosen as the basis for selecting the power reset (i.e. the course or distribution of the noise power was not taken into account).

Similar problems exist with poor conduction under current practices. If the maximum data rate cannot be reliably achieved with a suitable reception margin, there is no need to adaptively control the power (only select the maximum power). Instead, the issue here is controlling data rates to avoid excess rates (while maintaining receive margin levels). For example, for a line that is not experiencing fluctuations in noise power, a data rate of 2.0 Mbps might be appropriate to meet the desired retraining / CV or other performance-related criteria. However, for a line that often experiences a higher level of noise power, a data rate of 1.6 Mbps might be suitable instead. However, heretofore, a fixed reception margin target at the time of training has been used, and only the noise power at the time of training has been entered to select the data rate (i.e., the history or distribution of the noise power has not been taken into account). The following examples describe methods and techniques that use history and / or distribution.

Various operating data can be collected periodically or aperiodically for an ADSL line of interest. This data can contain the current reception margin, the current data rate, the current maximum achievable data rate, FEC correction numbers, CV numbers, retraining numbers, channel transfer functions and noise spectra. Furthermore, using collected operating data, the probability distributions of the reception margin, the maximum achievable data rate, FEC correction numbers, CV numbers, retraining numbers, etc. can be estimated as a function of the data rate. The channel transfer function and noise spectrum might not be immediately available to a controller if the operational data is only collected from the ATU-C side of an ADSL1 system, but at least some of the useful data can be estimated in such situations. Techniques for determining such estimates can be found in U.S. Application No. 10 / 817,128.

An example of a reception margin distribution curve is shown in FIG. For a specific collection data rate Rcollect, for example 3 Mbps, operating data is collected over time to determine the percentage of time that certain reception margins are used when a DSL line is operating at Rcollect. In the example of Figure 10, the DSL line uses a 16 dB reception margin to operate at 3 Mbps approximately 50% of the time. Likewise, for the same collection data rate, the DSL line uses a reception margin of 10 dB for approximately 10% of the time and a reception margin of 4 dB for approximately 1-2% of the time. By adding the total percentages for given reception margin ranges, the likelihood of operating at or below the uppermost reception margin in rate can be determined.

Reception margin is closely related to CV count, retraining rates, maximum data rates, and other related performance parameters. For example, high CV numbers and / or retraining rates can be statistically related to the number of upgrades required for a particular DSL line. Likewise, customer satisfaction (measured for example by the number of customers who forego a service from a specific operator) can be statistically correlated in the same way with the CV number and / or the retraining rates. Therefore, after determining the distribution (s) of one or more performance parameters (s) as a function of the data rate, the probability of a line failure (re-training of the line) and the probability that the CV number exceeds a threshold value can then also be calculated as a function of the data rate become. When performance thresholds / targets are of particular concern to an operator or other party, the present invention enables that party to adaptively control the data rate and / or use of the power / reception headroom around one or more of these

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Achieve goals.

The maximum power degradation (the minimum reception margin) or the maximum data rate can then be chosen while at the same time meeting the reliability criteria (e.g. the number of retrainings and the number of CVs exceeding a specified threshold).

For example, several thresholds for the number of retrains and the CV numbers can be used and the criteria can be as follows:

- Number of retraining sessions (per day) &lt;1 with a probability of 50% or more; and

- Number of retraining sessions (per day) &lt;3 with a probability of 90% or more; and

- Number of retraining sessions (per day) &lt;5 with a probability of 99% or more; and

CV number (per 15 minute period) &lt;2000 with a probability of 99% or more; and

- CV number (per 15 minute period) &lt;1000 with a probability of 95% or more; and

- CV number (per 15 minute period) &lt;500 with a probability of 90% or more.

The maximum power degradation or the highest data rate that meets all six criteria is then chosen.

A method 1100 in accordance with an embodiment of the present invention is illustrated in FIG. First, operating data for one or more data rates Rcollect is collected at 1110. Using this collected data, one or more distributions of a performance parameter (such as receive margin, as shown in Figure 10) are plotted at 1120 as a function of the given data rate used to collect the data. The highest data rate R that meets one or more performance goals is then selected at 1130. If at decision box 1140 the highest data rate that achieves the performance goal (s) is the maximum data rate (Rmax), then the performance parameter is optimized at 1150 to achieve this maximum rate (for example, by decreasing the reception margin or increasing the power reset). maintain. If the highest data rate the the achievement target (s) achieved, at 1130 not R_M.ax, the DSL line works at the selected R, and the performance parameter follows its distribution. To ensure that reliance on one or more distributions remains valid, the system can update itself, as shown in FIG. 11.

As illustrated in Figure 10, there is a general tradeoff between receive margin and data rate, and receive margin values ​​decrease as the data rate is increased. Based on the estimated and / or collected information, a controller can find a distribution of direct performance parameters of the DSL line, such as numbers of forced retraining, CVs, code error corrections, etc., based on the same data set used to estimate the distributions of various Performance parameter is used for a specific data rate. Then the retraining and CV criteria can also be implemented and interpreted in terms of scope for reception. On the basis of the above retraining and CV criteria, for example, the following reception leeway criteria can be applied to the management:

Reception margin must be over 3 dB 99% of the time

Reception margin must be over 5dB 95% of the time

Reception margin must be over 6dB 90% of the time

On the basis of the reception margin distribution, the maximum power reset or the maximum data rate can be chosen so that all three reception margin criteria are met for the DSL line under consideration. It is also possible to use the six Neut35 / 54

<img file="AT13387U2_D0036.tif" />

AT 13 387 U2 2013-11-15 to combine reinings and CV criteria with the three reception margin criteria in such a way that the risk associated with the estimation error can be reduced.

Embodiments of the invention can also be used analogously in situations in which a line experiences two different states with long dwell periods in both states. In such cases, two sets of reception margin distribution criteria can be formed and the appropriate set of criteria can be applied in detecting the current state. Obviously, the invention can also be extended to lines with three or more states.

In general, embodiments of the invention employ various processes involving data that is stored or transmitted in one or more modem (s) and / or computer system (s). Embodiments of the present invention also relate to a hardware device or other apparatus for performing these operations. This apparatus may be specially designed for the purposes required or it may be a general purpose computer selectively activated or reconfigured by a computer program and / or data structure stored in the computer. The processes presented here do not in themselves relate to a specific computer or other apparatus. In particular, various general purpose machines can be used with programs written in accordance with the present teachings, or it may be more practical to construct more specialized apparatus to carry out the required process steps. A particular structure for a number of these machines will be apparent to one of ordinary skill in the art from the following description.

Embodiments of the invention as described above utilize various method steps involving data stored in computer systems. These steps are those that require physical manipulation of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, or otherwise manipulated. It is sometimes convenient, principally for reasons of common usage, to refer to these signals as bits, bit streams, data signals, instruction signals, values, elements, variables, characters, data structures, or the like. It should be remembered, however, that all of these and similar terms are intended to be associated with the correct physical quantities and are simply practical labels given to those quantities.

Furthermore, the manipulations carried out are often referred to using terms such as identifying, adapting or comparing. In each of the modes of operation described herein that form part of the invention, these operations are machine operations. Machines useful for performing the operations of embodiments of the present invention include general purpose computers, processors, modems, or other similar devices. In all cases, the distinction between the operating procedures when operating a computer and the calculation procedure itself should be observed. Embodiments of the present invention relate to method steps for operating a computer in processing electrical or other physical signals to generate other desired physical signals.

In addition, embodiments of the invention further relate to computer readable media containing program instructions for performing various computer implemented operations. The media and program instructions can be those specially designed and constructed for the purposes of the present invention or can be of the type well known and available to those skilled in the computer software art. Examples of computer readable media include, but are not limited to, magnetic media such as hard drives, floppy disks, and magnetic tape; optical media such as CD-ROM discs; magneto-optical media such as floptical disks; and hardware devices specially configured to store and execute program instructions, such as read only memory devices (ROM) and random access memory (RAM).

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Examples of program instructions contain both machine code as generated by a compiler and files which contain higher level code which is executed by the computer with the aid of an interpreter.

Figure 8 shows a typical computer system used by a user and / or controller in accordance with one or more embodiments of the invention. Computer system 800 includes any number of processors 802 (also referred to as central processing units or CPUs) coupled to storage devices that include primary memory 806 (usually random access memory or RAM) and primary memory 804 (usually read-only memory). Memory or ROM) included. As is well known in the art, primary memory 804 is used to unilaterally transfer data and instructions to the CPU, and primary memory 806 is typically used to transfer data and instructions in a bi-directional manner. These two primary storage devices can contain any suitable one of the computer readable media described above. A bulk storage device 808 is also bidirectionally coupled to the CPU 802 and provides additional data storage capacity and may contain any of the computer readable media described above. The mass storage device 808 can be used to store programs, data, and the like, and is typically a secondary storage medium, such as a hard drive, that is slower than primary storage. It will be appreciated that the information held in the mass storage device 808 may, in appropriate cases, be incorporated by default as part of the primary storage 806 as virtual storage. A specific mass storage device such as a CD-ROM can also route data unidirectionally to the CPU.

The CPU 802 is also coupled to an interface 810 which has one or more input / output devices such as video monitors, trackballs, mice, keyboards, microphones, touch-sensitive displays, converter card readers, magnetic or tape readers, tablets , Input pens, speech or handwriting recognition devices, or other well-known input devices such as other computers, of course. Finally, the CPU 802 may optionally be connected to a computer or telecommunications network using a network connection, as shown generally at 812. Link 812 can be used for communication with the DSL system and / or modems of interest. In some cases, the computer system 800 may have a proprietary, dedicated, and / or other specific connection with the DSL system, possibly through facilities (e.g., a CO) of the operator or in some other suitable manner (e.g., through a connection to the NMS of a specific DSL system). With such connections it is considered that the CPU can receive information from the network and / or DSL system or can output information to the network and / or DSL system in the course of the execution of the method steps described above. The devices and materials described above are known to those skilled in the computer hardware and software arts. The hardware elements described above can define multiple software modules for carrying out the operations of this invention. For example, instructions for operating a receive margin monitoring and regulation controller may be stored on a mass storage device 808 (which may be or include a CD-ROM) and on a CPU 802 in conjunction with primary storage 806 and a suitable computer program product residing on the system 800 is used. In a preferred embodiment, the control is divided into software sub-modules.

Within the scope of the present invention, modifications and changes are possible for one skilled in the art, and the invention is not to be limited to the exact construction and operation as illustrated and described. Therefore, the described embodiments should be considered exemplary, and the invention should not be limited to the details given herein, but rather be defined by the claims and their full scope of equivalents.