DE10102867A1 - Analysis method for the data transfer properties of a data carrier in the form of twin wire cable uses remotely controlled modem with fast Fourier transform module for analysis of signal - Google Patents

Abstract

Method for analysis of a data carrier between its two ends using a modem (1) that comprises a transceiver amplifier (2), a data and program memory, a signal processor (3) and a spectrum analyzer (5) in the form of a FFT module for analysis of an incoming signal. The modem can be requested from its remote end to carry out a spectrum analysis of the data carrier (7) and to transmit characteristic values back to the remote end. Independent claims are also included for: (1) A modem for transferring digital data between two ends of a data carrier; (2) The use of a data transfer modem as an analysis device for determining the quality of a twin wire connection.

Description

The invention relates to a method for analyzing the data transmission properties of a data line, a modem for Performing this procedure and using a da transmission modems for this method.

For the transmission of data over long distances, especially re between two computers connected via data line generally known modems in analog and digital form. On Analog modem is for example in the German patent DE 34 16 818 described. An example of a digi tales multiton modem is in the European patent application EP 0 863 644 discloses. Both modems include a FFT module (FFT = Fast Fourier Analysis = real-time Fourier Analysis), which is used to generate and detect the data carrier signals is used.

Furthermore, special measuring systems are known which are used for measuring solution of the line properties can be used. This system me work if they are only used at one end of the line in reflectometer mode. The disadvantage here is that associated inaccuracy of results because that reflected Signal is attenuated on the way there and back.

Also known methods that the measurement results evaluate both ends of the line are with a maintenance connected to the line terminal, resulting in high staff costs through the calibration process. Here is a measurement device connected to the two ends of a data transmission link,  to the quality of the data transmission link determine and the maximum possible data transfer rate measure, or for possible faults on this To be able to locate data transmission route and to to verify.

So when analyzing a data link, it is previously required by appropriate staff who are physically to the two end points of the data link is going to connect the measuring devices mentioned above and here with possible interference influences or directly correspond to the maximum possible data transfer rate de Applying data signals to the transmission link to verify.

This method requires a lot of labor and is therefore with the currently growing number of Da cables are very difficult to carry out.

It is an object of the invention to provide a method for analyzing the Transmission quality of a data line and a match de device to find this, which allow ge lower costs to measure the data lines.

The object of the invention is through the features of the unab pending claims solved.

The inventor has recognized that the currently available standing modems, which via a spectral analysis module, usually a module for real-time Fourier transformation possible is to use this existing module to correspond either routinely from the software or through ei A measurement task of the maintenance team directly activated requirement  on the other hand, an analysis of the existing Da separate connection on the way there and back, where the measurement result of the Fourier analysis as a data file Maintenance team is transferred. This will make an fake result of performance from the far end Average: The characteristic values obtained from the spectral analysis (e.g. Fourier constants or parameters) can thus become "far analyze "the interference situation on the transmission link NEN.

For this it is necessary to close the known modem design that it corresponds from one opposite side to another accordingly trained initialization device or a command sequence is put into an analysis mode, in which it is its existing spectral analysis module activated to the interference signals of a certain connection o which is also a specific signal sent from the opposite side to analyze its frequency characteristics and to send the determined characteristic values back to the opposite side. If a Fourier analysis is carried out as a spectral analysis, then the characteristic values are the Fourier constants.

This can be the usual way for a maintenance technician to the customer of a data network operator and a we considerable savings. A realization of the invented Modems according to the invention can, for example, be purely software done so that in addition to the additional programming effort no further additional costs to a currently commercially available Modem arise.

The inventor strikes in accordance with this inventive idea before, the known method for analyzing a data line between a first and a second page with a modem  perform, the modem with at least one Sen the / receiver amplifier, at least one memory for data and / or programs, at least one signal processor and egg equipped with a means for spectral analysis of incoming signals tet is, according to the invention the modem from the opposite side is asked to do a spectral analysis of the data lines perform and characteristic values of the result of the spectralana send lysis back to the other side.

The characteristic values can preferably be based on the analyzed data line itself. In addition, as Spectral analysis is usually a harmonic analysis (Fou rier analysis), preferably in real time.

As mentioned earlier, spectral analysis can be done at one time point without data transfer, so that only the Interference signals are detected. On the other hand, there is also Possibility to differentiate signals during spectral analysis Licher frequency to transmit the damping characteristic to determine the data line.

Furthermore, the spectral analysis at the beginning of the verb development are carried out so that each individual ell, according to the results of the spectral analysis, the Use the highest possible data rate when transferring data can be detected.

According to the idea of the invention, the inventor proposes In addition, the well-known modem for the transmission of digital data between a first and a second te, over a 2-wire line, the modem with at least a transmitter / receiver amplifier, at least one memory for data and / or programs, at least one signal processor  and means for spectral analysis of incoming signals is equipped to improve that on the first modem located is designed such that on request, characteristic values of a self-conducted Spectral analysis of the connection to the second side to one Receiver on the second side via the 2-wire line ü berträgt.

The means for spectral analysis can be, for example, a pro be gram module, which corresponds to the signal processor controls, the spectral analysis mostly on a Fourier Transformation based and preferably pre-in real time is taken. As a signal processor, both a special suitable DSP (digital signal processor) or also any microprocessor with appropriate programming tion and peripherals can be used.

The modem can also be used as a "discrete multitone data menu transmission "modem be formed, since this data over transmission method interference signals particularly unfavorable to the possible maximum data transfer rate.

According to the idea of the invention, it is therefore possible that an integrated spectralana in a data transmission modem lyse module is used to measure the quality of a data line determine.

Further features of the invention result from the Unteran say and the following description of the execution examples with reference to the drawings.

In the following the invention with reference to in the drawings illustrated embodiments and applications nä described here. The individual shows:

Fig. 1: Functional structure of a known modem;

FIG. 2 shows functional structure of a modem according to the invention;

Fig. 3: Modem according to the invention in data transmission mode;

Fig. 4: Inventive modem in the analysis mode;

Fig. 5: Application example of the modem according to the invention.

Fig. 1 shows the functional structure of a known modem 1 , which is connected to an a / b line 7 of a Fernmeldenet zes and the user is connected to a personal computer 8 .

The modem 1 has for input and output of the data via a transmitter / receiver amplifier 2 , which receives the data to be sent from a digital signal processor 3 or passes the received data to this digital signal processor 3 . The digital signal processor 3 has access to a data / program memory 4 with an integrated FFT module 5 . The digital signal processor 3 is connected to a personal computer (PC) 8 via an interface 6 . If a modem comes into operation, the PC sends digital data to interface 6 of the modem. From there, they are routed to the digital signal processor 3 , which converts the data with the help of an FFT module 5 into signals of different frequencies with the aid of a suitable program on the data / program memory 4 and transmits these via the transmitter / receiver amplifier 2 to the a / b line 7 of the communication network transmits. On the opposite side is a corresponding modem, which in turn receives the frequencies via a transmitter / receiver amplifier 2 , forwards it to the digital signal processor 3 , which in turn converts these signals into digital data and uses the interface via the FFT module 5 6 the PC 8 connected to the modem 1 .

The basic functioning of such a modem is for example for an analog modem from the above mentioned German patent application DE 34 16 818 and for a Multiton modem from European patent application EP 0 863 644 known. Regarding the mathematical background to Fourier analysis is based on the detailed description of a discrete Fourier transform from the lecture "Discrete Fourier Transformation and Applications "by Marcus Bäckmann on the website http: / / www.baeckmann.de/wavelet_fourier.htm pointed.

FIG. 2 shows the structure of a modem according to the invention, which differs from FIG. 1 by the additional analysis module 9 .

FIGS. 3 and 4 demonstrate the difference of the loading operating condition of the modem 1 according to the invention in the data transfer mode and the analysis mode. The function blocks marked in bold represent the function blocks that are active in the respective mode.

In Fig. 3 it can be seen that in Datenübertragungsmo dus the transmission / reception amplifier 2, the DSP are activated 3, the data / program memory 4 to the FFT module 5 and the interface to the PC 6, while the analysis module 9 , via which the evaluation of the FFT takes place and the characteristic values of the spectral analysis are transmitted, is not activated.

In contrast to this, FIG. 4 shows an operating state of the modem 1 , in which the analysis module 9 is additionally activated and uses the FFT module, in which it activates it and exchanges the calculated characteristic values of the FFT and after their calculation via the a / b line 7 sends to the opposite station.

Fig. 5 shows by way of schematic drawing of the dung OF INVENTION proper function of the modem 1 for the analysis of an a / b connection 7 between a provider and a customer 10. 11 To analyze the a / b connection between provider 10 and customer 11 , provider 10 establishes a data connection to the customer via customer-side modem 1 and provider-side modem 1 '. Then the customer's modem is initialized, for example by a corresponding initialization code, for the analysis mode, whereupon the customer's modem activates its analysis module and with the help of the FFT module 5 he makes a spectral analysis of the noise on the data line 7 and then the characteristic values of the Spectral analysis, i.e. the Fourier constant, is transmitted to the provider 10 via the data line 7 .

Through these measures there is the possibility of interference and interference signals on the data connection between provider and Customers in a simple way and with the least amount of personnel allowed to recognize. This makes it possible the maximum possible to determine the data transfer rate, or even specifically to eliminate certain interferences.

Furthermore, by sending another command sequence, the provider can inform the customer's modem that it should now carry out an analysis of a specific transmitted frequency spectrum, the frequency spectrum being generated by the provider-side modem 1 '. The customer's modem 1 then carries out the spectral analysis of the received frequency spectrum and sends the calculated characteristic values back to the provider 10 . It can also be agreed between the modems that the customer's modem generates a certain frequency spectrum and transmits it on the data line, which is then analyzed by the modem 1 'on the provider side.

With this measurement, the damping characteristic of the Da tenleitung be measured, or certain Damage or weaknesses of the data line can be determined without that a maintenance technician personally goes to the customer got to. The measurement of the damping characteristic on both Pages carried out, so the irradiation can be correct interference signals, knowing the damping properties ten of the line from the ratio of the two lines the measured amplitudes.

It is understood that the above features of Invention not only in the specified combination, but also in other combinations or alone can be used without departing from the scope of the invention.

Overall, the inventive method and he inventive modem a very inexpensive way to Maintenance and definition of an existing data line, whereby it is also characterized by the fact that kei ne special hardware changes in the appropriate Modems are necessary, since it is sufficient, only the Pro programming of the modem to the inventive method to fit.  

LIST OF REFERENCE NUMBERS

1

modem

1

'Provider-side modem

2

Transmitter / receiver amplifier

3

digital signal processor

4

Data / Program Memory

5

FFT module

6

Interface to the PC

7

a / b line

8th

PC

9

Analysis Module

10

provider

11

customer

Claims (17)

1. A method for analyzing a data line ( 7 ) between a first and a second side with a modem ( 1 , 1 '), which has at least one transmitter / receiver amplifier ( 2 ), at least one memory ( 4 ) for data and / or programs, at least one signal processor ( 3 ) and a means for spectral analysis ( 5 ) of incoming signals, characterized in that the modem ( 1 ) is asked by the opposite side to carry out a spectral analysis of the data line ( 7 ) and characteristic values of the result the spectral analysis to the opposite side ( 1 '). 2. The method according to the preceding claim 1, characterized in that the characteristic values are sent back via the analyzed data line ( 7 ) itself. 3. The method according to any one of the preceding claims 1-2, characterized, that for spectral analysis a harmonic analysis (Fouriera analysis), preferably in real time. 4. The method according to any one of the preceding claims 1-3, characterized, that the spectral analysis at a time without data wearing takes place. 5. The method according to any one of the preceding claims 1-4, characterized,  that signals are different during spectral analysis Frequency are transmitted and the damping characteristic the data line is determined. 6. The method according to any one of the preceding claims 1-5, characterized, that the spectral analysis at the beginning of a connection establishment is carried out. 7. The method according to any one of the preceding claims 1-6, characterized, that spectral analysis on both sides of the data line is carried out and a comparison of the characteristics on one side values from both sides. 8. Modem ( 1 , 1 ') for transmitting digital data between a first and a second side, the two sides being connected to a 2-wire line ( 7 ), with at least one transmitter / receiver amplifier ( 2 ), at least one memory ( 4 ) for data and / or programs, at least one signal processor ( 3 ) and a means for spectral analysis ( 5 ) of incoming signals, characterized in that the modem ( 1 ) located on the first side is designed in such a way that, on request, it transmits characteristic values of a self-performed spectral analysis of the connection to the second side to a receiver ( 1 ') on the second side via the 2-wire line ( 7 ). 9. Modem according to the preceding claim 8, characterized in that the means ( 5 ) for spectral analysis is a program module. 10. Modem according to one of the preceding claims 8-9, characterized, that the spectral analysis ba on a Fourier transform Siert. 11. Modem according to one of the preceding claims 8-10, characterized, that the spectral analysis is a real time analysis. 12. Modem according to one of the preceding claims 8-11, characterized in that the modem ( 1 ) is a digital modem. 13. Modem according to one of the preceding claims 8-11, characterized in that the modem ( 1 ) is an analog modem. 14. Modem according to one of the preceding claims 8-13, characterized, that it out as a "discrete multitone data transmission" modem is formed. 15. Use of a data transmission modem ( 1 ) with an integrated spectral analysis module ( 5 ), preferably with an FFT module (FFT = real-time Fourier transform), for the quality determination of a data line ( 7 ). 16. Computer program product with program code means to at least the steps according to at least one of the claims 1-7 when the program code means in a pro processor.   17. Data carrier with a computer program with program code Means to perform at least the steps of at least one of claims 1-7 when the program code means run in a processor.