JPH07111490A - Transmission line test support device - Google Patents

Abstract

(57) [Abstract] [Object] The present invention relates to a transmission path test support device which is provided at both ends of a specific section of a transmission path and is used for confirmation of transmission characteristics in the section. The purpose of this is to conduct a confirmation test on a channel-by-channel basis based on comprehensive transmission characteristics between the two ends of the transmission section consisting of a plurality of transmission lines. [Structure] A switch 11 for switching transmission information and two transmission lines 1 for transmitting transmission information by different transmission methods.
Transmission line interface means 15 ₁ and 15 _2, which are arranged at the connection points of 3 ₁ and 13 ₂ and individually take an interface between these transmission lines and the switch 11, and transmission lines 13 ₁ and
Test interface means 19 which acts as an interface between the switch 11 and the tester 17 which transmits and receives the pseudo transmission information through the individual channels formed on the transmission line 13 ₂ and tests these transmission lines based on a predetermined standard. And is configured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission line test support device which is arranged at both ends of a specific section of a transmission line and is used for confirmation of transmission characteristics in the section.

[0002]

2. Description of the Related Art In recent years, digital transmission systems have been adopted in many communication networks, and existing analog transmission lines are being remodeled into new digital transmission lines one after another. As for the section where the analog transmission line remains due to such renovation, various items are checked prior to the start of operation to confirm that the transmission quality equal to or higher than that of the analog transmission line before the renovation can be obtained. Will be tested.

FIG. 10 is a diagram showing a conventional transmission line confirmation test method. In the figure, an analog type terminal 101
₁ and data terminal 102 ₁
The (TDM) 103 ₁ is connected via a digital transmission line (hereinafter, simply referred to as “transmission line”) 104 to the time division multiplexer 1.
03 ₂ (TDM). Time division multiplexer 103
₂ is an analog type terminal 101 ₂ and a data terminal 102
Accommodates ₂ and. Time Division Multiplexers 103 ₁ , 103
₂ is the bit error rate measuring devices 105 ₁ and 105 _{2 respectively.}
Connected to.

In the time division multiplexer 103 ₁ , the terminal 101
₁ and the data terminal 102 ₁ are a terminal interface unit (CHIF) 106 ₁ and a time switch (TSI) 107.
₁ and a transmission line interface (LIF) 108 ₁ to connect to the transmission line 104. Further, a predetermined port of the time switch 107 ₁ is connected to the test board (TEST) 1
09 ₁ is connected to the bit error rate measuring device 105 ₁ . Since the time-division multiplex device 103 ₂ has the same configuration as the time-division multiplex device 103 ₁ , the same reference number with the subscript “ ₂ ” is given to each corresponding constituent element. Then, the explanation is omitted.

In the transmission line confirmation test using the test circuit having such a configuration, if it is assumed that both ends of the transmission line 104 are sections modified from the analog type transmission line, both ends of the transmission line 104 are transmitted. Road interface unit 108 ₁ , 1
08 ₂ and time switches 107 ₁ and 107 ₂ are connected to bit error rate measuring devices 105 ₁ and 105 ₂ .

In such a state, the bit error rate measuring devices 105 ₁ and 105 ₂ generate bit strings (for example, PN code) of a predetermined series and send them to the bit error rate measuring devices facing each other. . Bit error rate measuring instrument 1
05 ₁ and 105 _{2 take} in such a bit string, compare it with a preset known bit string, and measure the bit error rate based on the result of the comparison.

Regarding the remaining analog transmission line connected to such a digital transmission line, the transmission line 104
By turning back at the connection point with and connecting a predetermined measuring device (not shown) to the connection point of the analog transmission line,
The group band level and the SN ratio are measured, and the transmission quality is confirmed and maintained based on the measurement result.

[0008]

However, since such a conventional transmission line confirmation test is performed separately for each section having a different transmission method, the test process is divided into a plurality of steps and the work efficiency is improved. However, it was not possible to grasp the comprehensive transmission line characteristics of that section. Further, especially for a communication network that is configured by complicatedly connecting a digital transmission line and an analog transmission line in series, a lot of man-hours are required for maintenance and operation, and there are test methods and devices that can significantly reduce the man-hours. It was requested.

The present invention provides a transmission line test support that enables a channel unit confirmation test based on comprehensive transmission characteristics between both ends of a transmission section consisting of a plurality of transmission lines which are different in transmission system and are connected in series. The purpose is to provide a device.

[0010]

FIG. 1 is a block diagram showing the principle of the invention described in claim 1. In FIG. The present invention is arranged at a connection point between a switch 11 that switches a transmission destination of transmission information and two transmission paths 13 ₁ and 13 ₂ that transmit transmission information by different transmission methods, and between the transmission path and the switch 11. The transmission line interface means 15 ₁ and 15 ₂ for individually taking an interface for each channel and the pseudo transmission information corresponding to the transmission information are transmitted and received to be monitored, and the transmission lines 13 ₁ and 13 ₂ are channeled based on the result of the monitoring. A tester 17 that tests each time,
And a test interface means 19 for interfacing with the switch 11.

FIG. 2 is a block diagram showing the principle of the invention described in claim 2. According to the present invention, the switch 21 for switching the transmission destination of the transmission information and the end of the transmission path 23 for transmitting the transmission information by a predetermined transmission method are connected to each other to form an interface for each channel between the transmission path and the switch 21. An interface is provided between the switch 21 and the transmission line interface means 25, a tester 17 that sends and receives pseudo transmission information corresponding to the transmission information to monitor, and tests the transmission line 23 for each channel based on the result of the monitoring. And a test interface means 27.

[0012]

The transmission line test support apparatus according to the present invention is individually arranged at the connection point of the transmission lines 13 ₁ and 13 ₂ and the other end of the test section having the connection point as one end. . In these transmission line test support devices, the transmission line interface means 15 ₁ and 15 ₂ serve as an interface between the test section and the switch 11 in conformity with the transmission method at each end of the test section described above. Switch 11
Forms a transmission information path between the test section and the test interface means 19 for the channel to be tested.

That is, at both ends of the test section, the two testers 17 face each other via the test interface means 19, the switch 11 and the transmission interface means 15 ₁ , 15 ₂ (15 ₂ , 15 ₁ ), respectively.

Therefore, by using these testers, pseudo transmission information is mutually transmitted and received at both ends of a test section constituted by connecting a plurality of transmission lines having different transmission systems in series, and comprehensive monitoring is performed. A test based on various transfer characteristics can be performed.

The transmission line test support device according to the invention of claim 2 is arranged at the end of the transmission line 23, and the invention or claim of claim 1 is provided at the other end of the test section having the end as one end. The transmission line test support device according to the present invention according to item 2 is arranged.

In the transmission test apparatus according to the second aspect of the present invention, the transmission line interface means 25 takes an interface between the test section and the switch 21 in conformity with the transmission method at the end of the test section. . The switch 21 forms a transmission information path between the test section and the test interface means 27 for the channel to be tested.

That is, at both ends of the test section, the test interface means 27, the switch 21, the transmission path interface means 25, the test section set in the transmission path 23, the transmission path interface means 15 ₁ (15 ₂ , 25),
Switch 11 (21) and test interface means 1
Two testers 17 face each other through 9 (27).

Therefore, by using these testers, pseudo transmission information is mutually transmitted and received at both ends of a test section constituted by connecting a plurality of transmission lines having different transmission systems in series, and comprehensive monitoring is performed. Testing based on transfer characteristics can be performed.

[0019]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 3 is a diagram showing a first embodiment corresponding to the invention described in claim 1.

The difference between this embodiment and the conventional example shown in FIG. 10, time-division multiplexing apparatus 103 _1, 103 ₂ division multiplexing apparatus when the configuration in terms of later differs instead (TDM) 30 _1, 3
0 ₂ comprises a, in place of the bit error rate measuring unit 105 _first low-frequency tester (OSC / LM) 31 ₁ and provided with a signaling tester 32 _1, instead of the bit error rate measuring unit 105 _second low-frequency tester ( The OSC / LM) 31 ₂ and the signaling tester 32 ₂ are provided.

The time division multiplexer 30 ₁ is a test board 109 ₁
In place of PCM codec 33 ₁ , ADPCM codec 34 ₁ and signaling test board 35 ₁ ,
CM codec 33 ₁ and ADPCM codec 34
_A low frequency tester 31 ₁ is connected to ₁ . A signaling tester 32 ₂ is connected to the signaling test board 35 ₁ . Since the time-division multiplexing device 30 ₂ has the same configuration as the time-division multiplexing device 30 ₁ , the same reference numeral with the subscript “ ₂ ” is given to the corresponding component, The description is omitted.

Regarding the correspondence between this embodiment and the block diagram shown in FIG. 1, the switch 107 is the switch 11
The transmission line 104 corresponds to the transmission lines 13 ₁ and 13 ₂ , and the terminal interface unit 106 and the transmission line interface unit 108 correspond to the transmission line interface units 15 ₁ and 1 1.
5 ₂ corresponds, the low-frequency tester 31 and signaling tester 32 corresponds to the tester 17, PCM codec 3
3, ADPCM codec 34 and signaling test board 35 correspond to the test interface means 19.

The operation of this embodiment will be described below. The low-frequency testers 31 ₁ and 31 ₂ each generate an analog test signal at a specified level according to the level diagram of the transmission line 104, and the signaling testers 32 ₁ and 32 ₂ each include a signaling signal (line) having a specified pattern. Signals) in chronological order. At both ends of the transmission path 104, the PCM codecs 33 ₁ , 33 ₂ (or ADPCM) for the channels to be subjected to the confirmation test are respectively transmitted via the transmission path interface units 108 ₁ , 108 ₂ and the time switches 107 ₁ , 107 _2. Codec 34
₁ , 34 ₂ ) and the signaling test boards 35 ₁ , 35 ₂ are connected. The time switches 107 ₁ and 107 ₂
In the inside, the call signal (transmission information) and the signaling signal are separated and combined based on the format of the passing PCM signal.

In such a state, the low frequency tester 31 ₁
The test signal sent from the PCM codec 33 ₁ is converted into a PCM signal, and the signaling signal generated from the signaling tester 32 _{1 in} parallel is sent through the signaling test board 35 ₁ to the P format of the above-mentioned format.
It is converted into a CM signal. The time switch 107 ₁ multiplexes the PCM signal applied in this way, and passes the time switch 107 ₁ via the transmission line interface unit 108 ₁ , the transmission line 104, and the transmission line interface unit 108 _2.
Give to _two .

The time switch 107 ₂ separates the call signal and the signaling signal by performing the processing opposite to the above-described multiplexing processing on the PCM signal thus provided. PCM codec 33 ₂ (or ADPCM
The codec 34 ₂ ) decodes the speech signal separated in this way, and the low-frequency tester 31 ₂ measures the level and SNR of the test signal restored by such decoding and outputs the result of the measurement. Output. Further, the signaling test board 35 ₂ supplies the signaling tester 32 ₂ with a signaling signal separated from the above-mentioned call signal.
The signaling tester 32 ₂ determines whether or not such a signaling signal is obtained in the above-described prescribed pattern, and outputs the result of the determination.

Further, between the time division multiplexers 30 ₁ and 30 ₂ , the above-mentioned operations are performed in parallel or alternately via the transmission line 104. Therefore, the low frequency tester 3
1 ₁ and the signaling tester 32 ₁ have a transmission line 104.
Similar measurement and judgment results can be obtained based on the total transmission characteristics in the opposite directions.

As described above, according to this embodiment, the time-division multiplexer is provided with a means for internally inserting and developing the PCM signal for each channel to interface with the low-frequency tester or the like. , Transmission line 104
It is possible to perform a confirmation test based on comprehensive transmission characteristics between both ends of the.

In this embodiment, the PCM codec 3
The confirmation test has been performed using _{one of} 3 ₁ (33 ₂ ) and ADPCM codec 34 ₁ (34 ₂ ).
The method is not limited to such a method, and may be appropriately selected and used according to the transmission method of the transmission path or the transmission method of the terminal that accesses the channel to be tested.

Further, in the present embodiment, the above-mentioned means is added to the time division multiplexer, but the present invention is not limited to such a constitution, and for example, the constitution of the time division multiplexer is modified. Instead, a transmission line test support device composed of equalizing means may be arranged in series with the time division multiplexer.

FIG. 4 is a diagram showing a second embodiment corresponding to the invention described in claim 1. In FIG. In the figure, the difference from the embodiment shown in FIG. 3 is that a time division multiplexer (TDM) 42 that interfaces with a transmission line 41 adapted to a 2 MHz PCM interface (primary group (eg, PCM 24, PCM 30)). It is provided in place of the time division multiplexer 30 ₂ .
The point is that a tester 43 is provided between the time division multiplexer 42 and the low frequency tester 31 ₂ and the signaling tester 32 ₂ .

Further, time division multiplexing apparatus 42 and the difference between division multiplexing apparatus 103 ₂ when shown in FIG. 10, PCM described above
Terminal interface part (CH
IF) 44 _{2 in place} of the terminal interface unit 106 ₂ to provide an interface with the tester 43.
5 ₂ is provided in place of the test panel 109 ₂ . The time division multiplexer 42 is connected via a transmission line 41 to a digital trunk accommodated in another station.

Regarding the correspondence between this embodiment and the block diagram shown in FIG. 1, the test board 45 ₂ and the tester 4
Reference numeral 3 corresponds to the test interface means 19, and the rest is the same as the embodiment shown in FIG.

The operation of this embodiment will be described below. The operation on the side of the time division multiplexer 30 ₁ is the same as that of the embodiment shown in FIG. 3, and therefore its explanation is omitted here.

In the time division multiplexer 42, the time switch 1
07 ₂ is a time division multiplexer 30 ₁ via the transmission line 104.
The insert / develop process is performed on a single channel, which is the target of the confirmation test, among the plurality of channels formed between the test channel 43 and the test channel 45 ₂ . Accessible.

In such a state, the tester 43 converts the analog test signal sent from the low frequency tester 31 ₂ into a digital signal suitable for the above-mentioned PCM interface, and further sends it from the signaling tester 32 _2. Test board 4 after being combined with the signal
5 ₂ , the time switch 107 ₂ , the transmission line interface unit 108 ₂ and the transmission line 104, and the time division multiplexer 3
0 ₁ is transmitted. Further, the tester 43 takes in the test signal and the signaling signal received via the transmission path 104, converts the test signal into an analog test signal and gives the analog test signal to the low-frequency tester 31 _2, and the signaling test for the signaling signal. To the vessel 32 ₂ .

As described above, according to this embodiment, the transmission line 10
No. 4, the test signal and the signaling signal are transmitted and received at a relay point between the transmission line and the transmission line 41 suitable for the primary group, and the signal level, the SN ratio, and other predetermined values are determined for these signals. A confirmation test can be performed based on the determined criteria.

FIG. 5 is a diagram showing a third embodiment corresponding to the invention described in claim 1. In FIG. In the figure, the difference from the conventional example shown in FIG.
And A / D converter via the (A / DTR) 51 is connected to the transmission path 52 adapted to existing FDM channel, that the low-frequency tester 31 ₂ is connected to a test terminal of the A / D converter 51 It is in. The tester 43 and the signaling tester 32 ₂ are not used.

In the A / D converter 51, the transmission line 41 is P
It is connected to the input of the conversion unit (CONV) 54 via the CM interface unit (PCMINF) 53, and its output is connected to the first input / output of the add / drop unit (D / I) 55.
The second input / output of the add / drop unit 55 is connected to the transmission line 52 via the FDM interface unit (FDMINF) 56, and the third input / output of the add / drop unit 55 is a low frequency test via the test terminal described above. Connected to the container 31 ₂ .

Regarding the correspondence relationship between this embodiment and the block diagram shown in FIG. 3, the add / drop unit 55 has the switch 11
Corresponding to the test interface means 19 and the transmission line 1
04, the time division multiplexer 42 and the transmission line 41 are the transmission line 1
3 ₁ , the transmission path 52 corresponds to the transmission path 13 ₂ , P
The CM interface section 53 and the conversion section 54 correspond to the transmission path interface means 15 ₁ , the FDM interface section 56 corresponds to the transmission path interface means 15 ₂ .
The low frequency tester 31 ₂ corresponds to the tester 17.

The operation of this embodiment will be described below. The operation on the side of the time division multiplexer 30 ₁ is the same as that of the embodiment shown in FIG. 3, and therefore its explanation is omitted here.

The time division multiplex device 42 includes transmission lines 104, 4 and 4.
A demultiplexing process suitable for the first transmission method is performed, and relay between these transmission lines is performed. A / D converter 51
Then, the PCM interface unit 53 separates / combines the PCM signal transmitted / received via the transmission line 41 for each channel based on the format of the signal. Converter 5
4 is for the PCM signal separated in this way,
A / D conversion processing and D / A conversion processing are performed in parallel.
The add / drop unit 55 relays, through the FDM interface unit 56 and the transmission path 52, the channels that are not subjected to the confirmation test among the channels converted into analog by the conversion unit 54, and are the target of the confirmation test. The low-frequency tester 31 ₂
Detour to.

As described above, according to this embodiment, it is suitable for the primary group.
Transmission adapted to the group band of the combined transmission line 41 and FDM line
At the relay point with the path 52, the time division multiplexer shown in FIG.
Thirty ₂Send and receive test signals in the same manner as
About signal level, signal-to-noise ratio and other predetermined
Confirmation test based on disconnection criteria for transmission lines 104 and 41
You can do it.

FIG. 6 is a diagram showing an embodiment corresponding to the invention described in claim 2. In FIG. In the figure, the difference from the embodiment shown in FIG. 3 is that the test section of the transmission line confirmation test is the transmission line 10
4 is provided between one end and the intermediate point, the distribution frame (IDF) 61 is provided at the intermediate point of the digital transmission path, and the transmission path test support device 62 is connected through the distribution frame. In point. Transmission line test support device 62
Is configured by deleting the terminal interface unit 106 ₂ from the described time division multiplexing device 30 ₂ .

Therefore, the operation of the transmission line confirmation test in this embodiment is the same as that of the embodiment shown in FIG. 3, and therefore its explanation is omitted here. It should be noted that the present embodiment is similarly subjected to the transmission line confirmation test regarding the existing section prior to the extension at the terminal end of the extension of the transmission line 104. Further, in such a transmission line confirmation test, instead of the transmission line test support device 62, for example, a time division multiplexer 30 ₂ including a terminal interface unit 106 ₂ as shown by a dotted line in FIG. 6 may be used.

Therefore, the above-mentioned embodiments are applied.
As a result, for example, as shown in FIG.
1₁Channel conversion from the analog transmission line 71 accessed by
Device (CHTR) 72, Group conversion device (GTR) 73₁,
Supergroup conversion device (SGTR) 74₁, Transmission line 75, supergroup change
Exchange device (SGTR) 74₂, Group conversion device (GTR) 73
₂And through a group pass filter (GTHF) 76
Group conversion device (GTR) 73₃Analog method
For the transmission line of, renovate to the digital transmission line
If the analog transmission line 71 is connected in cascade,
Split multiplexer 30 ₁, Staff multiplexing device 77₁, Transmission line 1
04, staff multiplexing device 77₂, Time division multiplexer 42
And time-division by replacing with A / D converter 51
Multiplexer 30₁And the A / D conversion device 51
The actual path is set for each individual channel.
A confirmation test can be performed in the state.

By combining the above-described embodiments, for example, for a transmission section whose both ends are connected to an analog transmission path, an arbitrary channel CH
For the section, a confirmation test is performed regardless of the combination of transmission methods in the section (Fig. 8 (a)-), and the same applies to the case where one or both of the sections is the transmission line 41 suitable for the primary group. A confirmation test can be performed (FIGS. 8B to 8C).

Further, regarding such a transmission line confirmation test, when the transmission line 104 is extended from its end or intermediate point, even if the transmission system of the extended section is an analog system (see FIG. 9 (a),) and a digital method using a primary group (FIG. 9 (b)) can be surely performed in the same manner.

[0048]

As described above, according to the present invention, with respect to a transmission section constituted by connecting a plurality of transmission lines having different transmission systems in series, a path is actually set between both ends to transmit and receive transmission information. , And monitoring, a confirmation test is performed based on the overall transmission characteristics of the transmission section.

Therefore, in the repair, maintenance, and operation of the transmission line, the work is simplified and the required man-hours are reduced as compared with the conventional example in which the transmission line confirmation test is performed by dividing the sections having the same transmission method. Therefore, the working environment can be improved and the cost can be reduced while improving the accuracy of the test.

[Brief description of drawings]

FIG. 1 is a principle block diagram of the invention according to claim 1.

FIG. 2 is a principle block diagram of the invention described in claim 2.

FIG. 3 is a diagram showing a first embodiment corresponding to the invention described in claim 1.

FIG. 4 is a diagram showing a second embodiment corresponding to the invention described in claim 1.

FIG. 5 is a diagram showing a third embodiment corresponding to the invention described in claim 1.

FIG. 6 is a diagram showing an embodiment corresponding to the invention described in claim 2.

FIG. 7 is a diagram illustrating a line repairing method to which the present invention is applied.

FIG. 8 is a diagram (1) showing a method of a transmission line confirmation test to which the present invention is applied.

FIG. 9 is a diagram (2) showing a method of a transmission line confirmation test to which the present invention is applied.

FIG. 10 is a diagram showing a conventional transmission line confirmation test method.

[Explanation of symbols]

 11,21 switch 13,23,41,52,71,75 transmission line 15,25 transmission line interface means 17 tester 19,27 test interface means 30,42,103 time division multiplexer (TDM) 31 low frequency tester (OSC / LM) 32 Serialing tester 33 PCM codec 34 ADPCM codec 35 Signaling test board 43 Tester 44, 106 Terminal interface unit (CHIF) 45, 109 Test board (TEST) 51 A / D converter (A / DTR) 53 PCM interface unit (PCMINF) 54 conversion unit (CONV) 55 separation / extraction unit (D / I) 56 FDM interface unit (FDMINF) 61 distribution frame (IDF) 62 transmission path test support device 72 speech path conversion device (CHTR) 73 group Conversion equipment (GTR) 74 Super-group converter (SGTR) 76 Group-pass filter (GTHF) 77 Staff multiplexer 101 Telephone terminal 102 Data terminal 104 Digital transmission line 105 Bit error rate measuring instrument 107 Time switch (TSI) 108 Transmission line interface unit ( LIF)

Claims (2)

[Claims] 1. A switch for switching a transmission destination of transmission information.
(11) and two transmission paths for transmitting the transmission information by different transmission methods
Transmission line interface means (15 ₁ , 15) arranged at connection points of (13 ₁ , 13 ₂ ) and individually taking an interface for each channel between these transmission lines and the switch (11).
₂ ) and pseudo transmission information corresponding to the transmission information are transmitted and received for monitoring, and the transmission path (13 ₁ , 13 ₂ ) is based on the result of the monitoring.
A transmission line test support device, comprising: a tester (17) for testing each channel for each channel; and a test interface means (19) for interfacing with the switch (11). 2. A switch for switching a transmission destination of transmission information.
(21) and a transmission path (23) for transmitting the transmission information by a predetermined transmission method
A transmission line interface means (25) connected to the end of the transmission line and serving as an interface for each channel between the transmission line and the switch (21), and transmitting and receiving pseudo transmission information corresponding to the transmission information for monitoring. A tester (17) for testing the transmission path (23) for each channel based on the result of the monitoring, and a switch (2)
1) A transmission line test support device, comprising: a test interface means (27) for interfacing with 1).