JPH0281548A - Transmission characteristic measuring method - Google Patents

Abstract

PURPOSE:To shorten time required for the measurement by using a MODEM for the transmission reception of a control data with lots of transmission quantity and the transmission reception of a measured data and using a tone code transmission reception means for the transmission reception of the control data with less transmission quantity. CONSTITUTION:MODEMs 13, 23 and tone code transmission reception means 16, 25 are provided as communication means, the MODEMs 13, 23 are used for the transmission reception of control data at the start of measurement with lots of transmission quantity and the transmission reception of measurement data and the tone code transmission reception means 16, 25 are used for the transmission reception of the control data with less transmission quantity. Thus, the number of times of usage of the MODEMs 13, 23 is reduced for one measurement and the time required for the changeover when the MODEM 13 in a measuring instrument 10 and a signal measuring means 12 at the receiver side use the circuit in common is reduced and the measuring time is shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a transmission characteristic measuring method capable of automatically measuring the transmission characteristics of a telephone line between offices or between an office and a terminal.

(Prior Art) A conventional general method for measuring the transmission characteristics of a telephone line will be described below.

FIG. 3 is a schematic diagram for explaining a conventional transmission characteristic measuring method. In this figure, 10 is a measuring device on the receiving side, 1
1, 12, 13, 14.15 are the measuring instruments 1o, respectively.
Signal sending means and signal measuring means within. Modemo as a means of communication. Automatic call receiving means, DSP (Digital
2o is a measuring device on the transmitting side that controls the measurement, and 21, 22, 23, and 24 are a signal sending means, a signal measuring means, and a communication means in the measuring device 20, respectively. The control means 24 is for controlling the measuring instrument 20 and the measurement sequence. 30a and 30b are two-wire telephone lines for sending and receiving calls.

Now, as shown in FIG. 3, there is a transmitting station equipped with a transmitting measuring device 20 that controls the measurement sequence, and a measuring device 10 whose measuring sequence is controlled by the transmitting measuring device 20.
If the telephone lines 30a and 30b are to be measured between stations on the receiving side equipped with the following, the measurement sequence will be as shown in FIG.

Next, the sequence will be explained in detail.

First, when the control means 24 in the measuring instrument 20 makes a call to the measuring instrument 10, the automatic receiving means 14 in the measuring instrument 10 automatically receives the call and closes the DC loop.

At this time, the control means 24 in the measuring device 20 detects that an incoming call has been received, for example, due to polarity reversal. Next, an audible sound of 1020 Hz is sent out as a pass check signal from the signal sending means 11 in the measuring instrument 1o. Next, when the control data is sent from the control means 24 in the measuring instrument 20 to the measuring instrument 10 via the modem 23, the measuring instrument 10 changes from the modem communication state to the measurement signal sending state, and the signal sending means 11 A measurement signal for a specific frequency is sent out. That is, if this measurement signal is measured by the signal measuring means 22 in the measuring device 20, the telephone line 3 at this frequency is
You can know the loss etc. of 0b.

Next, the measuring device 10 stops sending out the measurement signal from the signal sending means 11 and returns to the modem connection state, but the measuring device 2
The measurement state of the transmission characteristics is determined by receiving control data sent from the control means 24 within the control section 23 via the modem 23. Then,
This time, the signal sending means 21 in the measuring device 20 sends out a measurement signal regarding a certain frequency to the measuring device 10 via the telephone line 30a. This measurement signal is
The signal is measured by the signal measuring means 12 in the device, and then sent again from the modem 13 to the measuring device 20 as measurement data. Therefore, from this measurement data, it is possible to know the loss etc. of the telephone line 30a at this frequency.

Thereafter, measurements are repeated in the same manner while sequentially changing the frequency, and the telephone line 30a is automatically measured.

Measurement of the transmission characteristics of 30b is performed. After the measurement is completed, the DC loop is released from the measuring instrument 20, and accordingly, the measuring instrument 10 also releases its DC loop.

[Problem to be solved by the invention]

In the conventional transmission characteristic measurement method as described above, modemo 13
．． 23 used to exchange control data and measurement data between the measuring instruments 20 and 10, but in the measuring instrument 10 on the receiving side used for conventional measurement of transmission characteristics, the modem 13
and the signal measuring means 12 are composed of the same DSP (digital signal processing circuit) circuit, and each is operated by switching the control program.
There is a problem in that it is difficult and time-consuming to switch circuits when measuring transmission characteristics, and the time required for measurement becomes longer.

Also, instead of using a modem for sending and receiving control data and measurement data, tone codes (for example, MFC: Muiti
Frequency Cord, etc.) could be considered, but there was a problem that it would not be possible to cope with the large amount of transmission.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a transmission characteristic measuring method that can shorten the measurement time and can cope with an increase in the amount of transmission.

[Means for Solving the Problems] The transmission characteristic measuring method according to the present invention uses a modem for exchanging measurement data and exchanging control data with a large amount of transmission,
Tone code exchange means is used to exchange control data with a small amount of transmission.

(Function) In the present invention, a tone code exchange means is used to exchange control data with a small amount of transmission, and by reducing the number of times a modem is used in one measurement, circuit switching can be reduced.

〔Example〕

FIG. 1 is a schematic diagram for explaining an embodiment of the transmission characteristic measuring method of the present invention. In this figure, the same reference numerals as in FIG. 3 indicate the same parts. Reference numeral 16.25 is a tone code sending/receiving means, which sends/receives, for example, MFC or a single tone of a specific frequency.

The transmission characteristic measuring method of this invention is also as shown in FIG.
Basically, the sequence is the same as the conventional example shown in FIG. However, in this invention, modemo 1 is used as a means of communication.
3.23 and tone code exchange means 16.25,
Modemo 13.23 is used to send and receive measurement data and control data at the start of measurement where there is a large amount of transmission, and tone code sending and receiving means 16.25 is used to send and receive control data where there is a small amount of transmission.
The difference is that it uses In other words, the number of times the modemos 13 and 23 are used in - measurements is reduced, and the time required for switching when the modemos 13 and the signal measuring means 12 in the measuring device 10 on the receiving side share a circuit is reduced. This makes it possible to shorten measurement time.

〔Effect of the invention〕

As explained above, this invention uses a modem for sending and receiving measurement data and control data with a large amount of transmission, and uses a tone code sending and receiving means for sending and receiving control data with a small amount of transmission. The number of times of use can be reduced, and when the modem and signal sending means circuits are shared, the time required for switching is reduced, and the time required for measurement can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining the transmission characteristic measuring method of the present invention, FIG. 2 is a diagram showing the measurement sequence in the present invention, and FIG. 3 is a schematic diagram for explaining the conventional transmission characteristic measuring method. FIG. 4 is a diagram showing the measurement sequence. In the figure, 10 is a measuring device on the receiving side, 20 is a measuring device on the transmitting side,
11.21 is a signal sending means, 12.22 is a signal measuring means, 13.23 is a modemo, 14 is an automatic call receiving means, 15.2
4 is a control means, 16.25 is a tone code exchange means, 3
0a and 30b are telephone lines. Sword figure 3 30a, 30b:? iEK fortune telling system

Claims (1)

[Claims] A receiving side measuring instrument having a signal sending means, a signal measuring means, a communication means, an automatic call receiving means, a control means for controlling the operation, the signal sending means, the signal measuring means, the communication means, and the operation. and a transmitting-side measuring device having a control means for controlling a measurement sequence, and measuring the transmission characteristics of a telephone line between the transmitting-side measuring device and the receiving-side measuring device, the transmission characteristic measuring device comprising: Equipped with a modemo and tone code exchange means as a means of communication between the receiving side and the transmitting side,
A method for measuring transmission characteristics, characterized in that the modem is used for transmitting and receiving measurement data and for transmitting and receiving a large amount of control data, and the tone code transmitting and receiving means is used for transmitting and receiving a small amount of control data.