JPH02246635A - Characteristic evaluation system for repeater - Google Patents

Abstract

PURPOSE:To evaluate the characteristic of a repeater by using a pulse trio signal as a trigger signal for forming a loopback loop and inputting an evaluation measuring signal via a repeater in the loopback loop formed in this way to a line measuring instrument. CONSTITUTION:A pulse trio signal having a specific frequency component assigned to a repeater 331 is sent from a line measuring instrument 34 at first, which detects whether or not the pulse trio signal is looped back normally from the repeater 331. When the pulse is normally looped back, the instrument 34 sends an evaluation measuring signal for evaluating the characteristic for the repeater 331 to measure the characteristic. Then the pulse trio signal having a specific frequency component assigned to a repeater 338 is sent from the line measuring instrument 34, which detects the loopback to measure the characteristic of the repeater 338. Similarly, the measurement of the characteristic of each repeater is sequentially repeated in the direction of a repeater 33n.

Description

[Detailed Description of the Invention] (II Required) A simple and inexpensive a
In addition to evaluating and measuring various characteristics of the repeater,
A plurality of bidirectional terminals connected in tandem between the first primary group terminal 8 device and the second primary group terminal device are used for the purpose of monitoring the repeater up to the frequency limit of the filter. In a method for performing evaluation measurement of a repeater, one of a pulse trio signal and an evaluation measurement signal is selectively transmitted from at least one of the first and second primary group terminal equipment, and・Equipped with a line measuring device that receives the signal input to the primary group terminal equipment and performs various measurements, and a repeating frequency component of the pulse trio signal is assigned to each of the plurality of repeaters. A detection circuit for detecting whether the natural frequency is detected, and a switching means that is triggered by an output detection signal of the detection circuit when detecting the natural frequency and loops back the input signal for a fixed period m, After the signal is looped back and input, a predetermined evaluation measurement signal is sent out, and the evaluation measurement of the predetermined repeater is performed based on the evaluation measurement signal that is looped back and input via the predetermined repeater. Configure.

[Industrial application field]

The present invention relates to a method for evaluating the characteristics of a repeater, and more particularly to five methods for evaluating and measuring the characteristics of two-way intermediate repeaters connected in tandem and operated.

In recent years, as the frequency of use of transmission lines for data communication has increased, early detection and repair of faulty sections of primary group intermediate relay transmission lines in the event of line failure has become an urgent need.

For this reason, it is necessary for the maintenance station to use a general-purpose pulse trio generator to evaluate and measure the characteristics of the repeater for 7 ortho-O catering in the @ line state.

[Conventional technology]

FIG. 4 shows a block diagram of an example of the conventional method.

In the figure, various data from the subscriber 10 are stored in the primary group PCM.
The signal is supplied to a multiplex converter (MUX) 12 in the end station equipment 11, where it is supplied to a multiplex converter (MUX) 12 in the terminal equipment 11, where the pulse code change W(
PCM) data 24 channels is 1.544M
has or 30 channels of data is 2.048M
The data is multiplexed into bps and becomes primary group multiplexed data.

This primary group multiplexed data is transmitted to the terminal relay equipment (LTE) 13.
After the signal is amplified, superimposed with a feeding current, converted into a bipolar signal, etc., it is sent to the first-stage repeater 161 via 3out15.

As for the repeaters, n repeaters are connected in tandem as shown by 161 to 161, and monitoring filters 17+ to 171 are connected to each of the middle W units 16+ to 161, respectively.

The repeater 16+ includes amplifiers 18a, 18b, etc., and reproduces the same signal as the undistorted transmission signal and outputs it. The repeaters 162 to 161 also have the same configuration as the repeater 16+.

Also, monitoring filters 171 to 17? I have the same configuration, so to explain the monitoring filter 17+ as a representative, from the primary group PCM terminal device 11 to the primary group PCM
A band pass filter (hereinafter referred to as BPF) 19a is supplied with the input digital signal of the amplifier 18a that amplifies the digital signal transmitted toward the terminal 8 device 20, and -order group PC
MjEi station equipment! It consists of a BPF 19b to which an input digital signal of an amplifier 18b for amplifying the digital signal folded back and transmitted in the direction from 20 to 11 is supplied.

Here, the BPFs 19a and 19b are each configured to pass only signals of predetermined specific frequencies that are different from each other. Similarly, monitoring filters 172 to 171 provided corresponding to other repeaters 162 to 161 each have two B filters.
All of them are configured to pass only signals of a predetermined specific frequency.

The digital signal taken out from the repeater 1611 is supplied to the primary group PCM1 station device i20, where it is looped back and inputted again to the repeater 161, while being converted into a unipolar signal, reproduced and separated, etc. It is transmitted to the subsequent subscriber 21.

In such a digital transmission device, when the number of lines is set, the pulse trio generator 1 in the primary group PCM terminal equipment M11
The pulse trio signal generated in step 4 is sent to the transmission line via 5out15. Here, the pulse trio generator 14
is 3g where the two shown in Figure 5 (A) are positive and 1WJ is negative.
The first basic pulse (pulse trio) of one set of IJ and the second pulse of one set of three pulses, two of which are negative and one of which is positive, as shown in Figure (B).
This circuit generates a pulse pattern by alternately repeating the basic pulses (pulse trio) in sets corresponding to a predetermined cycle.

In other words, the transmission speed of the digital signal transmitted through the transmission line between the primary group PCM terminal equipment 511 and 20 is 1.54.
4M bps or 2.048M bps, and a pulse trio signal is transmitted as a signal for transmitting low frequency components at this transmission speed.

There are a total of 2n BPs in the monitoring filters 171 to 171.
Since the repetition frequency of the above-mentioned pulse trio signal is set to one of the 20 unique passing frequencies respectively determined in F, even if the repeater corresponding to the repetition frequency of the pulse trio signal at that time is normal. For example, the repetitive frequency component of the pulse trio signal is input to the measuring device 24 via the 5Vli 23, which is a monitoring line, and if a failure occurs in the corresponding repeater, the repetitive frequency component of the pulse trio signal is measured. It is not input to the device 24.

Therefore, the period of the pulse trio signal (low frequency repetition frequency) is changed sequentially, and the input signal level of the measuring device 24 is measured each time.If it is lower than the normal level, the repeater or repeater section at that point is faulty. If there is, it will be possible to locate it.

[Problem to be solved by the invention]

However, since the above conventional method only measures the level of the repeat frequency component of the pulse trio signal using the measuring device 24, it is only possible to locate a fault in the repeater or repeater section, and it does not directly measure the bit error rate or jitter. However, in order to measure them, it was necessary to separately provide a dedicated measuring means.

In addition, conventionally, the low-frequency repetitive frequency component of the pulse trio signal is transferred to the primary group PGM station equipment 11, which is a maintenance station, without repeating via the 5VI 123, so in the case of long-distance transmission, the Sv line A circuit is required to amplify the above-mentioned repetitive frequency component sent to R13, and since the repeaters 16+ to 161 do not have a JR source, the power supply current from the terminal repeater R13 is also increased due to the addition of the above-mentioned amplification circuit. There was a problem that if it were to be made large, the f1 would be expensive.

The present invention has been made in view of the above points, and provides a repeater that can evaluate and measure various characteristics of a repeater using a simple and inexpensive 4I, and also monitor the repeater up to the limit of the filter frequency. The purpose is to provide a method for evaluating the characteristics of

(Means for solving the problem With the device,
Relays 331 to 331 are connected in tandem between these. Reference numeral 34 denotes a line measuring device which sends out a pulse trio signal or an evaluation measurement signal from the primary group terminal 8 equipment 31, receives signals input from the repeater 331, and performs various measurements.

Note that this time 89'ls regulator 34 may be installed in the second primary group terminal equipment ff32, and both primary group terminal equipment 31
．． 32 may be present.

Furthermore, in the present invention, each of the repeaters 33+ to 33π is provided with detection circuits 351 to 35η and switching means 361 to 361. The detection circuits 351 to 351 detect whether the repetition frequency component of the pulse trio is a natural frequency assigned to itself.

The switching means 361 to 361 are triggered by the output detection in@ of the detection circuits 35+ to 35m when detecting the natural frequency, and return the input signal for a certain period wI.

[Effect]

The pulse trio signal sent out by the line measuring device 34 is sent out with its repetition frequency set to one of the frequencies unique to each of the detection circuits 351-351. For example, if the repetition frequency of this pulse trio signal is the natural frequency assigned to the detection circuit 351 in the repeater 331, then n-1(iR repeater 3
31 to 33111 (however, repeater 33 stop is not shown)
The pulse trio signal inputted to the repeater 331 in sequence is inputted to the detection circuit 351 via the switching means 361,
Here, the repetitive frequency component is detected. As a result, the detection circuit 35Tl outputs a detection signal to the switching means 3.
61, the pulse trio signal output to the second primary group terminal device 32 via the repeater 331 is returned by the repeater 331 and output to the repeater 33 direction. Therefore, for a certain period of time after the above-mentioned switching 11 is performed, there is no input signal to the second primary group terminal device 32, and the first primary group terminal station 1!
l[31→Repeater 331→...→Repeater 33π→Repeater 33 system→...→First primary group terminal device! 31 closed loops are formed.

The above folded pulse trio signal is sent to the repeater 3311.
.about.33+ and is input to the line measuring device 34. Thereby, the line measuring device 34 switches the signal to be sent to a predetermined evaluation measurement signal. This evaluation ilI+ measurement signal passes through the closed loop described above and is again used for 1-wire measurement s! 34.

Therefore, according to the present invention, loopback is performed at a repeater specified by the repetition frequency of the pulse trio signal,
The evaluation measurement signal via the repeater in the leap loop thus formed can be input to the 01m determiner 34. Further, since the pulse trio signal and the evaluation measurement signal are transmitted using the main signal system, a special amplification circuit for evaluation measurement is not required.

〔Example〕

FIG. 2 shows a block diagram of one embodiment of the inventive system. In the figure, the same components as in FIG. 1 are designated by the same reference numerals, and the same components as in FIG. 4 are designated by the same symbols, and their explanations will be omitted. In Fig. 2, 40 is the primary group PCM
A terminal device, which corresponds to the first primary group terminal device 31,
It is equipped with a line measuring device 34, and is configured to send the output signal of the line measuring device 34 to the 5ouL 15 and input the received signal from the Rout 41 to the line measuring device 34.

Further, 42 is a primary group PCM station device, which corresponds to the second primary group terminal station 32, and is a terminal station relay device (LTE).
43 and a multiplex converter (MUX) 44. nll! between the primary group PCM terminal devices 40 and 42! Repeater 3
3+ to 33n are connected in tandem.

In this embodiment, the line measuring device 34 first sends out a pulse trio signal having a repetitive frequency component of the natural frequency assigned to the repeater 331, and checks whether the pulse trio signal is returned normally from the repeater 2333+. To detect. If the signal is returned, an evaluation measurement signal for evaluating the characteristics of the repeater 33+ is sent out to measure the characteristics.

Next @l! The measuring device 34 sends out a pulse trio signal having a repetitive frequency component of the natural frequency assigned to the repeater 332, and the repeater 332 detects the return of the pulse trio signal.
Hereinafter, in the same manner, the characteristic measurements of each repeater are sequentially repeated in the direction of the relay 833η. Here, when forming a return loop using the pulse trio signal, which is performed in the order of repeaters 331 → 332 → ... → 33Tl, if there is a faulty repeater, the return loop at that time will not be formed. , since the pulse trio signal is not returned, it is possible to identify the repeater where the fault has occurred.

The repeaters 331 to 33TI described above are each ta-*, and have a configuration as shown in FIG. 3, for example.

In FIG. 3, AOIIT at A1 is an input terminal for signals transmitted from the primary PCM terminal device 40 in 42 directions.

Output terminals BIN and BOtjT are input terminals and output terminals for signals transmitted in the reverse direction. 46A and 46B are large regenerative relay circuits, and a transformer T+ is connected to the input terminal A1 from BIN.
, Ts, and performs bipolar-unipolar conversion (BU conversion) to convert the digital signal into transistor-transistor logic (T'r
L ) level unipolar signal.

47 is a switching circuit, 48A, 488G is a tU-8 converter, and the switching circuit 47 connects the output end of the regenerative relay circuit 46A to U-B.
*1! I! Either of the circuits 48A and 48B is connected to one of the input terminals, and the output terminal of the regenerative relay circuit 46B is connected to the U
-8 converters 48B and 48A are switched and connected to the input end of either one.

Each of the transformers Tz and T4 has an auxiliary winding, and the auxiliary winding is a band pass filter (BPF) 49A.

49B, connected to timers 51A and 51B via low frequency component detection circuits 50A and 50B, respectively, and switching circuit 4
It is connected to terminals LB (A) and LB (B) of 7. BPF49A passes the frequency fx, and BPF49B
is configured to pass the frequency t'y (?fX), and fx and fy are set to frequencies within the range of 1005H2 to 3016H2. These frequencies fx and fy are natural frequencies assigned to the repeater 33 in advance.

Tie v'51A, 51B is a low frequency component detection circuit 50A,
50B, and at the time of the trigger, a signal is output to the terminals SET (A) and SET (B) of the switching circuit 47, and after a predetermined period of time has elapsed, the signal is output to the set terminal RESET (
A), RESET (B) Outputs a reset signal.

As a result, the switching circuit 47 connects the output end of the regenerative relay circuit 46A to the input end of the U-8 converter 48B only at the above-mentioned fixed time interval, and connects the output end of the regenerative relay circuit 46B to the U-8 converter 48B.
Connect to the 8A input terminal.

The above BPFs 49A and 49B can be configured using switched capacitors, and the low frequency component detection circuits 50A and 50
BLtDPLL (Digital Phase,
0Cked L, OOD), and the tie v
Since 51A and 51B can be constructed using counters, and the switching circuit 47 can be constructed using a switch circuit, they are constructed from a large-scale integrated circuit (LSI) 52. This embodiment is characterized by having this LSI 52.

Among the circuits in this LSI 52, the BPF 49A, low frequency component detection circuit 50A, BPF 49B and low frequency component detection circuit 50B constitute the detection circuit 35 (any one of 351 to 351), and the timers 51A, 51B and switching The circuit 47 constitutes the switching means 36 (any one of 36+ to 361).

Next, the operation of the repeater 33 shown in FIG. 3 will be explained.

Assuming that the repetition frequency of the pulse trio signal to be transmitted is fx, the pulse trio signal input from the input end AIM to the regenerative repeater 46A via the transformer °[I is amplified, and the unipolar signals +DATA, -DAT
A, and the clock component CLK is extracted and input to the switching circuit 47.

Since the switching circuit 47 is normally connected to output the unipolar signal from the regenerative relay circuit 46A to the U-8 converter 48A, the unipolar signal described above is output to the U-8 converter 4.
8, where it is converted into a bipolar signal and then output to the output terminal A OUT via the transformer T2.

Further, only the low frequency component of the output bipolar signal (pulse trio signal here) of the U-8 converter 48 is input to the BPF 49A via the auxiliary winding of the transformer T2. As described above, since the repetition frequency of this input pulse trio signal is fX, the BPF 49A selects the low frequency component of this repetition frequency fx and supplies it to the low frequency component detection circuit 5OA.

As a result, the low frequency component detection circuit 50A outputs a detection signal, and the switching circuit 47 is connected to the output terminal of the regenerative relay circuit 46A.
-B converter 48B so as to be switched and connected to the input terminal, and also trigger timer 51A to maintain the connected state for a certain period of time determined by timer 51A.

As a result, the unipolar signal output from the regenerative relay circuit 46A is inputted to the U-8 converter 48B via the switching circuit 47, where it is converted into a pulse trio signal of bipolar signals, and then output 1B via the transformer T4. Output to OUT. Therefore, the time AI determined by the timer 51A
The digital signal input to M is turned back from B OUT.

When the returned pulse trio signal is received by the primary group PCM terminal device 40, as described above, an evaluation measurement signal is sent out from the line measuring device 34 and sent to the AI via the transmission path.
N, transformer T1 → regenerative repeater 46A → switching circuit 47 → U-8 converter 488 → transformer T4 → B O
It is turned back along the route UT.

The characteristics of the repeater in the return loop can be measured based on the evaluation measurement signal within the time determined by the timer 51A. The characteristics that can be measured include jitter, code error rate, etc., and this makes it possible to monitor the state of the repeater with higher accuracy.

By the way, during the folding loop formed using the pulse trio signal, the primary group PC equipped with the 11th measuring device 34
M terminal equipment is included. Therefore, the above case is a case where the primary group PCMI station equipment ff40 is equipped with the line measuring device 34 as shown in FIG.

On the other hand, if the primary group PCM terminal equipment 42 is equipped with a line measuring device 34, the line measuring device 34
When forming a loop that is folded back at the repeater shown in FIG. 3, the repetition frequency of the pulse trio signal is set to fy. As a result, the pulse trio signal is transferred to the primary group PCM [equipped with fi
The signal is transmitted in 42 directions, is looped back at the PCM terminal device 42, and is input to its ff1BIN.

The pulse trio signal input to BKH is transferred to transformer T3→
Regeneration relay circuit 46B → switching circuit 47 → U-8 conversion terminal 48
B→Transformer 4→B 0tlT is output, and the BPF 49B extracts the repetition frequency ry, so the detection signal is extracted from the low frequency component detection circuit 50B, triggers the timer 51B, and outputs the signal to the switching circuit 4.
7 is turned off and the output terminal of the regenerative relay circuit 46B is converted to U-8 for the time determined by the timer 51B. ! 48
It is kept in the off-N connection state connected to the input terminal of A.

After this, the signal input to BIN is changed to transformer T3 → regenerative relay circuit 46B → switching circuit 47 → U-B converter 48-
→Transformer T2→A OUT via the repeater 33
The signal is then looped back and transmitted toward the primary group PCM terminal device 42. As a result, the timer 5 is set in the same manner as above.
Medium WIN can be evaluated and measured within a certain period of time determined by 1B.

Note that after a certain period of time determined by the timers 51A and 51B has elapsed, the switching circuit 47 automatically returns to the original connection state by a reset signal output from the timers 51A and 51B.

〔Effect of the invention〕

As described above, according to the present invention, the pulse trio signal is used as a signal by the pulse trio signal for forming the folded loop, and the evaluation measurement signal transmitted through the middle M device in the folded loop thus formed is determined once. Since the input signal is input to the repeater, it is possible to evaluate the characteristics of the repeater, and the first and second detection circuits provided in the repeater can be combined with the cutting means 81, so that the main signal of system, it is possible to monitor up to the filter frequency limit even over long distances, there is no need for a pulse trio amplifier, and the above LSI
This system has features such as a simpler and cheaper configuration than the conventional one, and the ability to more accurately locate faults in repeaters or repeater sections using existing line measuring equipment.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a block diagram of an embodiment of the method of the present invention, Fig. 3 is a block diagram of an embodiment of the main part of the present invention, and Fig. 4 is a diagram of the conventional method. An example block diagram, FIG. 5, is a waveform explanatory diagram of a pulse trio. In the figure, 31 is the first primary group terminal device, 32 is the second primary group terminal device, 331 to 33 T1.33 is a repeater, 34 is a line measuring device, 351 to 351 is a detection circuit, 361 ~36Tl is a switching means, 47 is a switching circuit, 49A, 49B are bandpass filters (BPF), 50A, 5
0B is a low frequency component detection circuit, and 51A and 51B are timers.

Claims (1)

[Claims] A plurality of bidirectional repeaters (33_1 to 33_n), at least the first and second primary group terminal equipment (31,
32) selectively sends out one of the pulse trio signal and the evaluation measurement signal, and receives the signal input to the primary group terminal equipment (31 or 32) of the other, and performs various measurements. a detection circuit for each of the plurality of repeaters (33_1 to 33_n) to detect whether the repetitive frequency component of the pulse trio signal is a natural frequency assigned to the repeater; (35_1～
35_n) and the detection circuit (35_n) when detecting the natural frequency.
switching means (36_1 to 36_n) that is triggered by the output detection signal of
), after the pulse trio signal is input back by the line measuring device (34), a predetermined evaluation measurement signal is sent out, and the evaluation measurement signal is returned and input via a predetermined repeater. A characteristic evaluation method for a repeater, characterized in that an evaluation measurement of the predetermined repeater is performed based on a signal.