JP2741985B2 - Line quality measurement / transmission method and its implementation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a two-wire public line,
Line quality measurement that uses line-type leased lines or 4-wire-type leased lines and automatically measures group delay distortion and attenuation distortion by remote control in a point-to-point or multi-drop connection mode. The present invention relates to a transmission method and an apparatus for implementing the method.

[0002]

2. Description of the Related Art Normally, when a modem is installed, a person in charge of installation measures the distortion of an analog line using a line distortion measuring device. Thereafter, when an abnormality occurs in the line, the maintenance person measures the distortion of the analog line using the line distortion measuring device.

[0003] As a method of distortion measurement, CCITT 0.
81, IEEE 743, and the like, and CCITT V series as a data communication system. Since the distortion measuring device and the data communication device are independent, a manual switching operation is required.

[0004]

As described above, since a person goes to the station to install and measure, there is a problem that it takes at least several hours from the occurrence of a line abnormality to the completion of the measurement.

Further, the line distortion measuring device has a complicated circuit configuration and is expensive in order to improve the measurement accuracy.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to measure and transmit a line quality capable of shortening a work time from occurrence of a line abnormality to completion of measurement. It is to provide a method and a device for implementing it.

Another object of the present invention is to provide a line quality measuring / transmitting apparatus which simply makes the circuit configuration inexpensive and satisfies the required measuring accuracy.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0009]

In order to achieve the above object, a line quality measuring and transmitting method according to the present invention measures a group delay distortion and an attenuation distortion of an analog line and transmits the measurement result. In the transmission method, a measurement transmission / reception signal transmitted / received to measure the group delay distortion and the attenuation distortion, and a measurement result transmission / reception signal transmitting the measurement result, the step of dividing time in the same frequency band, and And the step of automatically measuring the group delay distortion and the attenuation distortion of the entire band by remote control by this switching.

[0010] Further, when measuring the attenuation distortion, a step of adjusting a transmission level of the transmission signal for measurement is provided.

A line quality measuring / transmitting apparatus according to the present invention is a line distortion measuring / transmitting apparatus having a distortion measuring means for measuring group delay distortion or attenuation distortion of an analog line and a modem for transmitting a measurement result. A measuring means / modem switching means which uses the same transmission / reception signal for measurement and the transmission signal for measurement result in the same frequency band by dividing the time; and the group delay distortion and attenuation of the entire band automatically by remote control by this means. And a group delay distortion / attenuation distortion measuring means for measuring distortion.

[0012]

According to the above-mentioned means, the modem is normally operating. When there is a measurement start instruction, first, a measurement completion detection timer is started, the mode is switched from the modem to the measuring means, the group delay distortion and the attenuation distortion are measured, and when the measurement is completed, the measuring means is switched to the modem, and the measurement result is obtained. Is transmitted. After this, the modem operates again. By doing so, it is possible to recognize the start and end of the distortion measurement, switch between the measurement means and the modem for transmitting the measurement result, and automatically measure the distortion of the analog line by remote control. The working time from the occurrence of an abnormality to the completion of measurement can be reduced.

If there is an attenuation distortion characteristic due to the component characteristics of the transmission / reception unit, the distortion due to the component characteristics of the transmission / reception unit is measured in advance, and the level of the measurement signal is adjusted to the inverse characteristic to obtain the final characteristic. Since errors in the measurement results can be corrected, the circuit configuration can be simply made inexpensive, and the required measurement accuracy can be satisfied.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram for explaining an embodiment of a line quality measuring and transmitting apparatus according to the present invention.
Is a transmitting section of the modem, 2 is a transmitting section of the signal for measuring distortion, 3 is a transmitting section switch, 4 is a receiving section of the modem, 5 is a receiving section of the signal for measuring distortion, 6 is a receiving section switch, and 7 is the center. Arithmetic processing unit (C
PU), a measurement completion detection timer for detecting completion of group delay distortion and attenuation distortion measurement, and 9 a programmable ROM (PROM). The PROM 9 stores a predetermined transmission level for each frequency for correcting distortion caused by the characteristics of the transmission unit 2 and the reception unit 5 of the distortion measurement signal.

Next, the operation of the line quality measuring / transmitting apparatus according to the present embodiment will be described.

In FIG. 1, the control unit 7 normally puts the transmitting unit switch 3 on the transmitting unit 1 side of the modem and the receiving unit switch 6
Is switched to the receiving section 4 side of the modem. Thus, data transmission and reception are performed.

When measuring the group delay distortion and the attenuation distortion, the control unit 7
Switches the transmission unit switch 3 to the distortion measurement signal transmission unit 2 side and switches the reception unit switch 6 to the distortion measurement signal reception unit 5 side. At this time, the transmission level for each frequency refers to that stored in the PROM 9 so as to correct the distortion of the signal for distortion measurement due to the characteristics of the transmission unit 2 and the reception unit 5.
When the characteristics of the transmission unit 2 and the reception unit 5 of the distortion measurement signal are different, the contents of the PROM 9 are changed to cope with this.

The completion signal of the measurement of the group delay distortion and the attenuation distortion is generated when the timeout of the measurement completion detection timer 8 is notified to the control unit 7. The control unit 7 switches the transmission unit switching unit 3 to the transmission unit 1 side of the modem and the reception unit switching unit 6 to the reception unit 5 side of the modem by the completion signal of the measurement of the group delay distortion and the attenuation distortion. And the measurement result is transmitted by the modem.

A method for switching between the measuring means and the modem means according to this embodiment will be described with reference to FIG. 2 (flow chart).

Normally, the modem function is operating (step 101). When there is a measurement start instruction (Step 10
2) First, the measurement completion detection timer 6 is started (step 103). Next, the mode is switched from the modem unit to the measuring unit (step 104), and the group delay distortion and the attenuation distortion are being measured (step 105). This state continues until the measurement completion detection timer 8 times out (step 106). When a timeout occurs, the current time is switched from the measuring means to the modem means (step 107), and the measurement result is transmitted (step 108). Thereafter, the modem means operates again (step 101).

It is assumed that there is an attenuation distortion characteristic as shown in FIG. In contrast, FIG.
When the transmission level characteristic as described above is provided, the final measurement result is a characteristic in which an error is corrected as shown in FIG.

As can be seen from the above description, the start and end of the distortion measurement are recognized, the measurement means and the modem for transmitting the measurement result are switched, and the distortion of the analog line can be automatically measured by remote control. Therefore, the working time from the occurrence of a line abnormality to the completion of measurement can be reduced.

If there is an attenuation distortion characteristic due to the component characteristics of the transmission / reception unit, the distortion due to the component characteristics of the transmission / reception unit is measured in advance, and the level of the signal for measurement is adjusted to the inverse characteristic to obtain the final characteristic. Since errors in the measurement results can be corrected, the circuit configuration can be simply made inexpensive, and the required measurement accuracy can be satisfied.

Although the present invention has been described in detail with reference to the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments and can be variously modified without departing from the scope of the invention. .

[0026]

As described above, according to the present invention, the group delay distortion and the attenuation distortion of each line can be automatically measured remotely, so that the working time from the occurrence of a line abnormality to the completion of the measurement can be reduced. Can be shortened.

Further, since the error of the final measurement result can be corrected, the circuit configuration can be made simple and inexpensive.
Moreover, the required measurement accuracy can be satisfied.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining an embodiment of a line quality measuring and transmitting apparatus according to the present invention;

FIG. 2 is a flowchart for explaining a method of switching between a measuring unit and a modem unit according to the embodiment;

FIG. 3 is a diagram illustrating attenuation distortion characteristics due to component characteristics of a transmission / reception unit of the present embodiment;

FIG. 4 is a diagram showing transmission level characteristics corresponding to the attenuation distortion characteristics shown in FIG.

FIG. 5 is a diagram showing characteristics in which errors in final measurement results of the present embodiment are corrected.

[Explanation of symbols]

1. Transmitter of modem 2. Transmitter of distortion measurement signal 3.
Transmission section switcher, 4 ... Modem reception section, 5 ... Distortion measurement signal reception section, 6 ... Reception section switcher, 7 ... Control section, 8 ... Measurement completion detection timer, 9 ... Programmable ROM (PRO)
M).

Claims (3)

(57) [Claims] 1. A transmission / reception signal for transmission / reception for measuring said group delay distortion and attenuation distortion in a line quality measurement / transmission method for measuring group delay distortion and attenuation distortion of an analog line and transmitting the measurement result. And the step of dividing the time in the same frequency band between the measurement result transmission / reception signals transmitting the measurement result, the step of using this to switch the distortion measurement means and the measurement result transmission modem, and the remote control by this switching. And automatically measuring the group delay distortion and the attenuation distortion of the entire band. 2. The line quality measuring and transmitting method according to claim 1, further comprising a step of adjusting a transmission level of the transmission signal for measurement when measuring the attenuation distortion. Method. 3. A transmission / reception signal for measurement and said measurement result in a line distortion measurement / transmission device having a distortion measurement means for measuring group delay distortion or attenuation distortion of an analog line and a modem for transmitting a measurement result. Measuring means / modem switching means for use in the same frequency band with transmission signals separated by time, and group delay distortion / attenuation for automatically measuring the group delay distortion and attenuation distortion of the entire band by remote control by this means A line quality measuring / transmitting device comprising a distortion measuring means.