CN101741426B - Method, device and system for enhancing stability of DSL circuit - Google Patents

Abstract

The invention provides a method, a device and a system for enhancing stability of DSL circuit. The method comprises the following steps: obtaining actual noise of a receiver end on the DSL subcarrier; performing statistical analysis to the actual noise of the receiver; determining reference virtual noise according to the statistical analysis of the obtained actual noise of the receiver on the subcarrier and relevant parameters of SOS mechanism for urgent speed reduction and configuring a user template according to the related parameters of SOS and the determined reference virtual noise. The scheme of the invention needs not to set the virtual noise at the maximum, when the actual noise is lower than the virtual noise, the speed of the user can be avoided from losing too much, and when the condition for starting urgent speed reduction mechanism SOS is satisfied, the urgent speed reduction mechanism SOS can be started to ensure the stability of user service.

Description

A kind of method, Apparatus and system that improves the DSL track stability

Technical field

The present invention relates to the communications field, relate in particular to a kind of method, Apparatus and system of the DSL of raising track stability.

Background technology

the DSL technology is a kind of twisted pair telephone that passes through, it is the high speed transmission technology that unshielded twisted pair is carried out transfer of data, comprise ADSL (Asymmetric Digital Subscriber Line) (Asymmetrical Digital Subscriber Line, ADSL), Very-high-speed Digital Subscriber Line (Very-high-bit-rate Digital Subscriber Line, VDSL), based on integrated services digital network (Integrated Services Digital Network, ISDN) number line (ISDN Digital Subscriber Line, IDSL), single-line high speed digital subscriber line (Single-pair High-bit-rate Digital Subscriber Line, SHDSL), second generation ADSL (Asymmetric Digital Subscriber Line) (Asymmetrical Digital Subscriber Line 2, ADSL2), the second generation ADSL (Asymmetric Digital Subscriber Line) of extended frequency band (Asymmetrical Digital Subscriber Line2plus, ADSL2plus), second high-speed digital user wire (Very-high-bit-rate DigitalSubscriber Line 2, VDSL2) etc.

In various digital user line technologies (xDSL), except the DSL of the baseband transmission such as IDSL and SHDSL, adopt the DSL of passband transmission to utilize frequency multiplexing technique to make DSL and Plain Old Telephone Service (Plain Old Telephone Service, POTS) coexist in on a pair of twisted-pair feeder, wherein DSL occupies high band, POTS takies the following baseband portion of 4KHz, POTS signal and DSL signal by separate/integrator (Splitter) separates or merges.

Each line of twisted-pair feeder of using due to DSL between be non-shielding, the electromagnetic interference between line pair can cause the signal on a pair of twisted-pair feeder that the signal on other a pair of twisted-pair feeder is exerted an influence, and namely crosstalks.Along with the development of DSL technology, speed is more and more higher, and spectral range is more and more wider.In the DSL of a new generation technology VDSL2, the maximum two-way 200Mbps of line speed, spectral range can reach 30MHz.So wide spectral range causes VDSL2 very responsive to the noise of crosstalking between cable, the coupling such as radio frequency interference (RFI) is come, and the error rate can occur in actual applications high, the situations such as drop rate height.

Virtual noise (Virtual Noise) scheme is a kind of method that improves track stability wherein.In the pre-configured transmitting terminal reference virtual of the transmitting terminal of DSL, reference virtual will pass to receiving terminal in the process of DSL training, receiving terminal can obtain the attenuation characteristic Hlog (f) of each subcarrier in training process, and calculates the reference virtual at receiving terminal.Receiving terminal is got wherein maximum with the receiving terminal actual noise and the receiving terminal reference virtual that obtain in training process, determine again bit and the gain of the distribution on each subcarrier, thereby guarantee after the DSL line activation, have higher noise margin on each subcarrier, can resist contingent noise jamming, improve the stability of circuit.

The inventor finds, although use above-mentioned virtual noise technology can improve to a certain extent the stability of circuit, also sacrificed the line speed of user's focus attentions equally on when guaranteeing to greatest extent circuit stable.

Summary of the invention

The object of the present invention is to provide a kind of method, Apparatus and system of the DSL of raising track stability, when can avoid improving track stability in prior art, sacrifice the transmission rate of subscriber's line.

Technical scheme of the present invention:

A kind of method that improves the DSL track stability, the method comprising the steps of:

Obtain the actual noise of the receiving terminal on the DSL subcarrier;

Described receiving terminal actual noise is carried out statistical analysis;

According to the statistical analysis of the receiving terminal actual noise of the receiving terminal actual noise of the described subcarrier that obtains and the described subcarrier that obtains and the relevant parameter that urgent speed reduces machine-processed SOS, determine reference virtual;

According to the relevant parameter of SOS and the reference virtual configure user template of determining.

A kind of in DSL the method for configure user template, the method comprising the steps of:

A, the relevant parameter that reduces machine-processed SOS according to urgent speed are determined reference virtual;

B, according to the relevant parameter of described SOS and definite reference virtual configure user template.

A kind of Digital Subscriber Line Access Multiplexer comprises housing, transmitting element and receiving element, and described transmitting element and receiving element are arranged in housing, is used for the sending and receiving of data, it is characterized in that, this Digital Subscriber Line Access Multiplexer comprises:

The noise acquiring unit is used for obtaining the receiving terminal actual noise on the DSL subcarrier;

Statistical analysis unit is carried out statistical analysis to described receiving terminal actual noise;

Computing unit is used for determining reference virtual according to the statistical analysis of the receiving terminal actual noise of the receiving terminal actual noise of the described subcarrier that obtains and the described subcarrier that obtains and the relevant parameter that urgent speed reduces machine-processed SOS.

A kind of broadband network system comprises:

Local side apparatus;

Ustomer premises access equipment, and;

The reference virtual determination module is arranged in local side apparatus or network management system, and this reference virtual determination module has: the noise acquiring unit is used for obtaining the receiving terminal actual noise on the DSL subcarrier; Statistical analysis unit is carried out statistical analysis to described receiving terminal actual noise; And computing unit, be used for determining reference virtual according to the statistical analysis of the receiving terminal actual noise of the receiving terminal actual noise of the described subcarrier that obtains and the described subcarrier that obtains and the relevant parameter that urgent speed reduces machine-processed SOS.

Beneficial effect of the present invention: embodiments of the invention arrange virtual noise in conjunction with the characteristic of SOS; when using virtual noise; coordinate SOS; with regard to unnecessary virtual noise arrange very large; in the situation that noise is less than virtual noise; can avoid the too much unnecessary loss of user rate, in the situation that noise greater than virtual noise, can start the stability that SOS protects customer service.Simultaneously, due to the setting that virtual noise is arranged, the startup of SOS can be so not frequent yet, and the number of times of rate reduction has obtained effective control.Can give full play to like this strong point of virtual noise technology and SOS technology, avoid defective separately, can guarantee that track stability does not lose again the purpose of too much transmission rate thereby reach.

Description of drawings

Fig. 1 is the system architecture schematic diagram of the embodiment of the present invention;

Fig. 2 is the method flow diagram of the embodiment of the present invention.

Embodiment

As shown in Figure 1, the broadband network system of the embodiment of the present invention, comprise: ustomer premises access equipment 12 and local side apparatus 16, ustomer premises access equipment 12 is generally digital subscriber link modem, it links with local side apparatus 16, ustomer premises access equipment 12 can send message to local side apparatus 16, also can receive and process the message that local side apparatus 16 sends simultaneously.

Local side apparatus 16 is specially Digital Subscriber Line Access Multiplexer (DSLAM, Digital SubscriberLine Access Multiplexer), Digital Subscriber Line Access Multiplexer comprises housing, transmitting element and receiving element, described transmitting element and receiving element are arranged in housing, are used for the sending and receiving of data.

The reference virtual determination module of the embodiment of the present invention can be arranged in local side apparatus 16 or in network management system according to actual needs, also can be independent of miscellaneous equipment and arrange separately.The reference virtual determination module specifically comprises: the noise acquiring unit is used for obtaining the receiving terminal actual noise on the DSL subcarrier; Statistical analysis unit is carried out statistical analysis to described receiving terminal actual noise; And computing unit, be used for receiving terminal actual noise and the statistical analysis of the receiving terminal actual noise of the subcarrier that obtains and the relevant parameter that urgent speed reduces machine-processed SOS according to the subcarrier that obtains, determine reference virtual.

As shown in Figure 2, the method for the embodiment of the present invention comprises the following steps:

S201, noise acquiring unit obtain the actual noise of the receiving terminal on the DSL subcarrier, and be as shown in table 1 below:

Table 1

Wherein K represents the number of tone, and T represents the number of times of collection parameter.

In this step, the method of obtaining the receiving terminal actual noise of DSL has multiple, the noise acquiring unit can by direct measurement or by indirect calculation or read the actual noise that data with existing obtains the receiving terminal on the DSL subcarrier, wherein can have following three kinds of methods by indirect calculation at least:

Method one: enable in advance online reconfiguration (On-Line Reconfiguration, OLR) characteristic, and monitoring period is set; In monitoring period, collect the parameter of each subcarrier after online reconfiguration is adjusted, utilization is collected reshuffles the calculation of parameter of each subcarrier that obtains in the parameter of each subcarrier after adjustment and training process, by calculating the receiving terminal actual noise on each subcarrier of DSL.

Defined the online reconfiguration characteristic in the DSL standard, in line condition or the slow variation of external noise environment generation, allow DSL under the prerequisite that does not go offline, automatically adjust current configuration parameter, to guarantee that DSL still can keep performance and stability preferably.The online reconfiguration characteristic mainly comprises: bit exchange (Bit Swapping, BS); Dynamic rate correction (Dynamic RateRepartition, DRR); Seamless rate adjustment (Seamless Rate Adaptation, SRA) etc.

Wherein, bit exchange refers to according to the signal to noise ratio on current each subcarrier, redistribute the bit (Bi on each subcarrier, 0＜i≤subcarrier number) and the gain (Gi, 0＜i≤subcarrier number), namely adjust Bi and Gi, but total speed (∑ Lp) remains unchanged, wherein Lp is each physical medium relevant (sublayer) (Physical Media Dependent (sublayer), PMD) bit number of p time-delay passage carrying in the symbol; DRR refers to according to the signal to noise ratio on current each subcarrier, redistributes the bit of each time delay passage, namely adjusts Lp, but total speed (∑ Lp) remains unchanged; SRA refers to according to the signal to noise ratio on current each subcarrier, redistributes the bit of each time delay passage, namely adjusts Lp, adjusts simultaneously bit and the gain of each subcarrier, in other words, adjusts Bi and Gi, and this moment, total speed (∑ Lp) can change.

The online reconfiguration characteristic allows DSL in the process that activates, variation and predefined target noise margin according to the line conditions generation, adjust within the specific limits bit carrying number and transmitted power on each subcarrier, adapt to the circuit noise variation thereby reach, keep the purpose of track stability.Conversely, the noise situation of change on the circuit has also been reacted in the adjustment of online reconfiguration.Therefore, each parameter after adjusting by the collection online reconfiguration, and the parameter of each subcarrier that obtains in training process can calculate the size of circuit noise, i.e. the receiving terminal actual noise of each subcarrier at this moment.By the statistics of a period of time (i.e. default monitoring period), can draw the maximum noise value of the receiving terminal actual noise of each subcarrier on circuit.Can determine reference virtual according to this maximum noise value, utilize the reference virtual of determining that DSL reference virtual parameter is configured, thereby the DSL circuit noise tolerance limit after having guaranteed to activate can be resisted contingent noise jamming.

Wherein, the parameter of each collected subcarrier comprises: the bit of the power spectral density of each subcarrier, signal to noise ratio surplus and distribution; The parameter of each subcarrier that obtains in training process comprises: the attenuation characteristic of each subcarrier.Perhaps, the parameter of each collected subcarrier comprises: the signal to noise ratio surplus of each subcarrier, bit and the gain of distribution; The parameter of each subcarrier that obtains in training process comprises: the attenuation characteristic of each subcarrier and reference power spectrum density.

Method two: set in advance the retraining monitoring period, or the retraining number of times; In the retraining monitoring period, or in the retraining number of times, collect the parameter of each subcarrier after training; The calculation of parameter of each subcarrier that utilization is collected is by calculating the receiving terminal actual noise on each subcarrier of DSL.

Because in the training process of DSL, receiving terminal can be measured the characteristic of channel, obtain attenuation characteristic Hlog (i) and the receiving terminal actual noise Actual_Received_Noise (i) of each subcarrier on channel, thereby calculate the signal to noise ratio snr (i) of each subcarrier, and calculate the bit (Bi of the distribution of each subcarrier, 0＜i≤subcarrier number) and the gain (Gi, 0＜i≤subcarrier number).Conversely, transmitting terminal and receiving terminal be by modulation system and the agreement of standard code, and exchange parameter mutually obtains the Bi of receiving terminal, Gi, and Hlog (i) etc. can calculate receiving terminal actual noise Actual_Received_Noise (i).Through " repeatedly retraining ", can draw the maximum noise value of the receiving terminal actual noise of each subcarrier on circuit.

Wherein, the parameter of each subcarrier after collected training can comprise: bit and the attenuation characteristic of the power spectral density of each subcarrier, signal to noise ratio surplus, distribution; The parameter of each subcarrier after collected training also can comprise: the signal to noise ratio surplus of each subcarrier, the bit of distribution, gain, attenuation characteristic and reference power spectrum density.

Method three: set in advance DELT number of Dual-Ended Loop Test; In the Dual-Ended Loop Test number of times, from the test result of Dual-Ended Loop Test, obtain the receiving terminal actual noise on each subcarrier of DSL.

Because defined the Dual-Ended Loop Test characteristic in DSL, the Dual-Ended Loop Test characteristic is in the DSL training process, entry-line diagnostic mode (Loop Diagnostic mode) carries out, and the Output rusults of Dual-Ended Loop Test comprises the parameters such as static noise QLN (i) on circuit, and this static noise is the receiving terminal actual noise on the corresponding subcarrier of DSL.Through carrying out repeatedly Dual-Ended Loop Test, can draw the maximum noise value of the receiving terminal actual noise of each subcarrier on circuit.Can determine reference virtual according to this maximum noise value, utilize definite reference virtual that the reference virtual parameter of DSL is configured, thereby the DSL circuit noise tolerance limit after having guaranteed to activate can be resisted contingent noise jamming.

Therefore, carry out the single or multiple Dual-Ended Loop Test in the method, and obtain the receiving terminal actual noise on each subcarrier of DSL from test result.

In practical application, above-mentioned three kinds of methods can also be used in combination, and for example, make up wherein any two kinds, or use simultaneously above-mentioned three kinds.Receiving terminal actual noise on collected DSL subcarrier some are better often.

S202, statistical analysis unit are carried out statistical analysis according to the receiving terminal actual noise on collected DSL subcarrier to actual noise.

Can carry out statistical analysis according to the noise of each subcarrier, also can merge several subcarriers in groups, group is carried out statistical analysis.In this step, with all the receiving terminal actual noise sequences on each subcarrier or in each group, then statistical computation parameter:

Suppose that virtual noise is Noise (i),

Be illustrated on k subcarrier or k group in Noise the probability of VN+Margin (dB), as shown in table 2 below:

Table 2

Owing to noise allowance (Margin) being arranged with the stability of protection circuit when the line activation; so when Noise occurring in certain the subcarrier k on circuit or certain group k〉during the situation of VN+Margin (dB); cyclic redundancy check (CRC) in subcarrier k or group k increases, and threatens the stability of circuit.

S203, computing unit determine reference virtual according to the statistical analysis of the receiving terminal actual noise of the receiving terminal actual noise of the described subcarrier that obtains and the described subcarrier that obtains and the relevant parameter that urgent speed reduces machine-processed SOS.The parameter that SOS is relevant comprises one of startup probability of SOS subcarrier number SOS_NTONES or SOS cyclic redundancy check (CRC) SOS_CRC or SOS at least.In the present embodiment, the parameter that SOS is relevant is the target start probability of SOS_NTONES and SOS.

SOS is the another kind of method that improves track stability, after activating (showtime), certain section interior interference due to noise of time, surpass maximum constraints and the cyclic redundancy check (CRC) (CRC that sets in advance when the number of these subcarriers, cyclic redundancy check) surpass the maximum that sets in advance, to start SOS, and reduce the error rate and exceed the bit that loads on these subcarriers of normal level, and make these subcarriers have more capacity of Noise.

Reduce the retraining that can avoid the DSL circuit to cause due to noise effect after mechanism (SOS) starts due to urgent speed, but can reduce the speed of DSL circuit, so, in conjunction with SOS, a virtual noise is set and can maximizes the speed that the user can reach.

According to the statistics of step S202 to actual noise, when $\mathrm{VN}={\mathrm{Noise}}_i^k,$ The probability that k subcarrier may cause SOS is So the startup probability of SOS and SOS-NTONES and

Relevant and obedience item distributes, and can represent with following expression formula so start the probability of SOS:

${\mathrm{Psos}}_i^k=\underset{t=N:K}{\mathrm{\Σ}}{C}_K^t\·{\left(p_i^k\right)}^t\·{(1-p_i^k)}^{K-t}$

If on k subcarrier different

As VN, can obtain different Then obtain different

Traversal owns

Make respectively different

Be VN, calculate one for each VN

Again all VN are calculated

Compare with user's SOS target start probability, find out with SOS target start probability and approach the most

Should

Fixed VN is required reference virtual.

Specifically can carry out according to the following steps:

Get i=1, $p_i^k=p_1^k,$ ${\mathrm{VN}}^k={\mathrm{Noise}}_1^k,$ k∈K

1, calculate ${\mathrm{Psos}}_i^k=\underset{t=N:K}{\mathrm{\Σ}}{C}_K^t\·{\left(p_i^k\right)}^t\·{(1-p_i^k)}^{K-t}$

2, relatively

Target start probability with SOS:

If 3 ${\mathrm{Psos}}_i^k<\mathrm{SOS}$ The target start probability, i=i+1, repeating step 1～3;

If ${\mathrm{Psos}}_i^k=\mathrm{SOS}$ The target start probability,

It is exactly required virtual noise;

If ${\mathrm{Psos}}_i^k>\mathrm{SOS}$ The target start probability, It is exactly required virtual noise.

The size of virtual noise can be adjusted according to user's requirement: if the user is not very high to the requirement of transmission rate, also do not wish frequent starting SOS, can suitably strengthen virtual noise; If the user has relatively high expectations to transmission rate, and can tolerate the frequent starting of SOS, can suitably reduce virtual noise, in order to have a higher message transmission rate in the situation that actual noise is less.

It is more accurate that those of ordinary skill in the art should be known in by above-mentioned steps S201, S202 and the resulting reference virtual of S203, but the flow process relative complex some.The technical staff is in the situation that consideration SOS determines roughly rule of thumb that directly the empirical value of a reference virtual also is fine.

S204: according to reference virtual and the SOS relevant parameter configure user template determined.

Owing to determining that in the step S204 of the present embodiment virtual noise is the startup probability according to parameter S OS_NTONES and SOS.So when the configure user template, come the configure user template according to the startup probability of the SOS_NTONES that obtains and SOS and the reference virtual that calculates.

And the configuration of the SOS_CRC parameter in template is as far as possible little, so just can make SOS_NTONES become the major parameter whether control starts SOS.

Certainly, if start SOS, after reducing the speed of DSL circuit, when the error rate on subcarrier still exceeded normal level, transmitting terminal and receiving terminal can restart to activate, and further increased the virtual noise that sends.

Embodiments of the invention arrange virtual noise in conjunction with the characteristic of SOS, when using virtual noise, coordinate SOS, with regard to unnecessary virtual noise arrange very large, in the situation that noise is less than virtual noise, can avoid the too much unnecessary loss of user rate, in the situation that noise greater than virtual noise, can start the stability that SOS ensures customer service.Simultaneously, due to the setting that virtual noise is arranged, the startup of SOS can be so not frequent yet, and the number of times of rate reduction has obtained effective control.Can give full play to like this strong point of virtual noise technology and SOS technology, avoid defective separately, can guarantee that track stability does not lose again the purpose of too much transmission rate thereby reach.

Be more than the explanation to the specific embodiment of the invention, can be improved appropriately the solution of the present invention in concrete implementation process, to adapt to the needs of concrete condition.Therefore, the specific embodiment of the present invention just plays an exemplary role, not in order to limit protection scope of the present invention.

Claims (8)

1. method that improves the DSL track stability, the method comprising the steps of:

Obtain the actual noise of the receiving terminal on the DSL subcarrier;

Described receiving terminal actual noise is carried out statistical analysis;

Calculate according to the statistical analysis of the receiving terminal actual noise of the receiving terminal actual noise of the described subcarrier that obtains and the described subcarrier that obtains and start the startup probability that urgent speed reduces machine-processed SOS under the different virtual noise

With described

Compare with user's SOS target start probability, find out with described SOS target start probability and approach the most

Determine describedly to approach the most

Corresponding virtual noise is reference virtual;

According to the relevant parameter of SOS and the reference virtual configure user template of determining.

2. method according to claim 1, it is characterized in that, receiving terminal actual noise on the described DSL of obtaining subcarrier is specially: enable in advance the online reconfiguration characteristic, and monitoring period is set, in monitoring period, collect the parameter of each subcarrier after online reconfiguration is adjusted, utilize the calculation of parameter of each subcarrier that obtains in the parameter of reshuffling each subcarrier after adjustment collected and training process, by calculating the receiving terminal actual noise on each subcarrier of DSL; Or

Set in advance the Dual-Ended Loop Test number of times, in the Dual-Ended Loop Test number of times, obtain the receiving terminal actual noise on each subcarrier of DSL from the Dual-Ended Loop Test result.

3. method according to claim 1, it is characterized in that, receiving terminal actual noise on the described DSL of obtaining subcarrier is specially: set in advance retraining monitoring period or retraining number of times, collect the parameter of each subcarrier after training in the retraining monitoring period or in the retraining number of times, the calculation of parameter of each subcarrier that utilization is collected is by calculating the receiving terminal actual noise on each subcarrier of DSL.

4. method according to claim 3, is characterized in that, the parameter of each subcarrier after the training of described collection comprises: bit and the attenuation characteristic of the power spectral density of each subcarrier, signal to noise ratio surplus, distribution; The parameter of each subcarrier after collected training comprises: the signal to noise ratio surplus of each subcarrier, the bit of distribution, gain, attenuation characteristic and reference power spectrum density.

5. a Digital Subscriber Line Access Multiplexer, comprise housing, transmitting element and receiving element, and described transmitting element and receiving element are arranged in housing, is used for the sending and receiving of data, it is characterized in that, this Digital Subscriber Line Access Multiplexer comprises:

The noise acquiring unit is used for obtaining the receiving terminal actual noise on the DSL subcarrier;

Statistical analysis unit is carried out statistical analysis to described receiving terminal actual noise;

Computing unit is used for statistical analysis according to the receiving terminal actual noise of the receiving terminal actual noise of the described subcarrier that obtains and the described subcarrier that obtains and calculates and start the startup probability that urgent speed reduces machine-processed SOS under the different virtual noise

With described

Compare with user's SOS target start probability, find out with described SOS target start probability and approach the most

Determine describedly to approach the most

Corresponding virtual noise is reference virtual.

6. Digital Subscriber Line Access Multiplexer according to claim 5, is characterized in that, the receiving terminal actual noise on the described DSL of obtaining subcarrier is specially: directly measure and obtain or obtain or read the data with existing acquisition by indirect calculation.

7. broadband network system comprises:

Local side apparatus;

Ustomer premises access equipment, and;

The reference virtual determination module is arranged in local side apparatus or network management system, and this reference virtual determination module has: the noise acquiring unit is used for obtaining the receiving terminal actual noise on the DSL subcarrier; Statistical analysis unit is carried out statistical analysis to described receiving terminal actual noise; And computing unit, be used for statistical analysis according to the receiving terminal actual noise of the receiving terminal actual noise of the described subcarrier that obtains and the described subcarrier that obtains and calculate and start the startup probability that urgent speed reduces machine-processed SOS under the different virtual noise

With described

Compare with user's SOS target start probability, find out with described SOS target start probability and approach the most

Determine describedly to approach the most

Corresponding virtual noise is reference virtual.

8. broadband network system according to claim 7, is characterized in that, described local side apparatus is Digital Subscriber Line Access Multiplexer DSLAM specifically.

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