JPH05236105A - Subscriber line fault monitoring system - Google Patents

Abstract

(57) [Abstract] [Purpose] Regarding a subscriber line fault monitoring system for confirming the normality of an ISDN subscriber line accommodated in a digital exchange, to improve reliability and maintainability of the digital exchange as much as possible. To aim. In the subscriber line accommodation device 100, the elapsed time is measured when the subscriber line 2 is unused, and the subscriber line test means 103 is activated every time a predetermined time elapses. The time establishing means 102 and the communication establishing means 2 in the same process as the communication establishing means 101 each time the time establishing means is activated.
01, confirms the normality of the subscriber line, and when the normality of the subscriber line is confirmed, the time limit means is provided with the subscriber line test means 103 for restarting the measurement of the elapsed time. The line test means is configured to immediately stop the operation of confirming the normality of the subscriber line when a call via the subscriber line occurs.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a subscriber line fault monitoring system for confirming the normality of a subscriber line for an integrated service digital network (hereinafter referred to as ISDN) accommodated in a digital exchange.

[0002]

2. Description of the Related Art FIG. 4 is a diagram showing an example of a conventional digital exchange, FIG. 5 is a diagram showing an example of a signal flowing through a subscriber line in FIG. 4, and FIG. 6 is a conventional subscriber line fault monitoring. It is a figure which shows an example of a process.

In FIG. 4, a subscriber line 2 for ISDN is used.
Is terminated at both ends by a digital subscriber circuit (DLC) 12 provided in the digital exchange 1 and a network terminating device (NT) 31 provided in the subscriber premises 3, and the digital subscriber circuit (DLC) 12 is , The subscriber line 2 is accommodated in the network (NW) 11, and the network terminator (NT) 3
1 connects one or a plurality of terminal devices (DT) 33 installed in a subscriber's home 3 to a subscriber's line 2 via a home communication path 32.

The digital subscriber circuit (DLC) 12 is
5 to the network terminating device (NT) 31 via the subscriber line 2.
, The downlink signal S _D is repeatedly transmitted at a constant cycle (frame F), and the network terminating device (NT) 31 sends the digital subscriber circuit (DLC) 12 via the subscriber line 2.
In addition, the upstream signal S _U as shown in FIG. 5 is repeatedly transmitted at a constant cycle (frame F).

Each frame F of the downlink signal S _D and the uplink signal S _U is provided with two sets of information channels B1 and B2, one set of control channel D and miscellaneous information channel X. In the miscellaneous information channel X of S _D, the activation signal START and the activation signal A each consisting of 1 bit
CT and a deactivation signal DEACT are included, and the miscellaneous information channel X of the upstream signal S _U includes a synchronization establishment signal SYN and an activation signal ACT each consisting of 1 bit.

In FIGS. 4 to 6, when no call is set up via the subscriber line 2, the digital subscriber circuit (DLC) 12 receives the start signal STA in the downlink signal S _D.
RT, activation signal ACT and deactivation signal DEACT are all set to logic "0", information transmission / reception via information channels B1 and B2 in downlink signal S _D , and various controls via control channel D Power consumption is suppressed by stopping signal transmission and reception.

The network terminating device (NT) 31 also receives a downlink signal S transmitted from the digital subscriber circuit (DLC) 12.
_When the activation signal START, the activation signal ACT, and the deactivation signal DEACT in D are all set to logic "0", the synchronization establishment signal SYN and the activation signal ACT in the upstream signal S _U are both logic. Set to “0” and the upstream signal S
Transmission and reception of information via the information channels B1 and B2 in _U and transmission and reception of various control signals via the control channel D are stopped to suppress power consumption.

In such a state, for example, the digital exchange 1
When an incoming call occurs via the subscriber line 2 to the digital subscriber circuit (DLC) 12, the digital subscriber circuit (DLC) 12 sets the activation signal START and the deactivating signal DEACT in the downlink signal S _D to the logic "1".

In the network terminating device (NT) 31, the activation signal START and the deactivating signal DEACT in the downlink signal S _D transmitted from the digital subscriber circuit (DLC) 12 are set to logic "1". , The synchronization establishment signal SYN in the upstream signal S _U is first changed to the logic “1” and then the activation signal ACT is changed to the logic “1” to cancel the suppression of the power consumption. It enables transmission / reception of information via the information channels B1 and B2 in the upstream signal S _U and transmission / reception of various control signals via the control channel D.

The digital subscriber circuit (DLC) 12 is
After changing the setting of the start signal START and the deactivating signal DEACT in the down signal S _D to logic "1" respectively,
Within a predetermined time (for example, 15 seconds), the synchronization establishment signal SYN in the upstream signal S _U transmitted from the network terminating device (NT) 31 is set and changed to the logic “1”, and the predetermined time is further set. Activation signal AC within (for example, 0.5 seconds)
When it is detected that T has been changed to the logic "1", it is determined that the communication path has been normally established via the subscriber line 2,
Setting and change the activation signal ACT in the downlink signal S _D to a logic "1", the information channels in the downlink signal S _D B1 and B2
, And the control signal is started via the control channel D.

The digital subscriber circuit (DLC) 12
Within a predetermined time (for example, 15 seconds) after changing the setting of the start signal START and the deactivating signal DEACT in the downlink signal S _D to logic "1", respectively, within the network terminating device (NT) 31 If the synchronization establishment signal SYN in the upstream signal S _U transmitted from the device is not changed to the logic “1”, it is determined that the communication path has not been normally established via the subscriber line 2 and Subscriber line 2 for unmaintained maintenance equipment
Notify of failure.

The terminal device (DT) 33 in the subscriber's home 3
From the digital subscriber circuit (D) through the subscriber line 2 to the digital exchange 1 as well.
The LC) 12 confirms the normality of the communication path passing through the subscriber line 2 in substantially the same process, and then the information channels B1 and B2.
, And the control signal is started via the control channel D.

[0013]

As is apparent from the above description, in the conventional digital exchange 1, when the call is not set up via the subscriber line 2, the communication via the subscriber line 2 is performed. Since the normality of the communication path passing through the subscriber line 2 was confirmed for the first time after the call via the subscriber line 2 occurred, the normality of the path was not confirmed. When a failure occurs, the call that has occurred cannot be set up, and there is a problem that the reliability and maintainability of the digital exchange 1 are degraded.

An object of the present invention is to improve the reliability and maintainability of the digital exchange as much as possible.

[0015]

FIG. 1 is a diagram showing the principle of the present invention. In FIG. 1, 2 is a subscriber line, 100 is a subscriber line accommodation device provided inside the office of a digital exchange and terminating the subscriber line 2, and 200 is provided in a subscriber's house and terminates the subscriber line 2. Network terminators, 101 and 2
Reference numeral 01 is a communication establishing means for confirming the normality of the communication path when a call is set up via the subscriber line 2.

Reference numeral 102 is a time limit means provided in the subscriber line accommodation device 100 according to the present invention. 103 is a subscriber line test means provided in the subscriber line accommodation device 100 according to the present invention.

[0017]

When the subscriber line 2 is in an unused state, the time limit means 102 measures the elapsed time and activates the subscriber line test means 103 every time a predetermined time elapses.

The subscriber line test means 103 is a time limit means 10
Each time it is activated by 2, the normality of the subscriber line 2 is confirmed with the communication establishing means 201 in the same process as the communication establishing means 101, and when the normality of the subscriber line 2 is confirmed, the time limit is set. The means 102 is restarted to measure the elapsed time.

It is considered that the subscriber line test means 103 immediately stops the operation of confirming the normality of the subscriber line 2 when a call via the subscriber line 2 occurs. Therefore, with no call set up via the subscriber line,
Since the normality of the communication path through the subscriber line is always confirmed, it is possible to detect a failure that occurs on the subscriber line before a call occurs, and perform appropriate diagnosis and repair processing. Greatly improves reliability and maintainability.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 2 is a diagram showing a digital exchange according to an embodiment of the present invention, and FIG. 3 is a diagram showing an example of a subscriber line fault monitoring process in FIG. The same reference numerals denote the same objects throughout the drawings. The signal flowing through the subscriber line is shown in FIG.
As shown in.

In FIG. 2, a digital subscriber circuit (DLC) 1 is used as the subscriber line accommodation device 100 in FIG.
2 is shown in the digital exchange 1, a network terminating device (NT) 31 is shown in the subscriber's premises 3 as the network terminating device 200 in FIG. 1, and a timer circuit (TM) 121 is shown as the timing means 102 in FIG. A subscriber line test section (TST) 12 provided in the digital subscriber circuit (DLC) 12 and serving as the subscriber line test means 103 in FIG.
2 are provided in the digital subscriber circuit (DLC) 12.

In FIG. 2, the digital subscriber circuit (DL) is used in the state where no call is set up via the subscriber line 2.
C) 12 transmits miscellaneous information channel X for each frame F to network terminating device (NT) 31 via subscriber line 2.
The activation signal START, the activation signal ACT, and the deactivation signal DEACT are all set to logic "0", and the network terminator (NT) 31 switches the subscriber line 2 for each frame F. Via Digital Subscriber Circuit (DLC)
The synchronization establishment signal SYN and the activation signal ACT in the miscellaneous information channel X, which are being transmitted to 12, are both set to logic "0", and the digital subscriber circuit (DLC) 12
The network terminator (NT) 31 suppresses power consumption.

In such a state, the digital subscriber circuit (D
The LC) 12 activates the timer circuit (TM) 121 when a call is not set up via the subscriber line 2.
The started timer circuit (TM) 121 starts measuring the elapsed time, and starts the subscriber line test unit (TST) 122 when a predetermined time (for example, 1 minute) elapses.

The activated subscriber line test section (TST) 12
In the same process as when an incoming call to the subscriber's line 2 occurs in the digital exchange 1, 2 sets and changes the activation signal START and the deactivating signal DEACT in the downlink signal S _D to logic "1".

In the network terminating device (NT) 31, the activation signal START and the deactivating signal DEACT in the downlink signal S _D transmitted from the digital subscriber circuit (DLC) 12 are set to logic "1". , The synchronization establishment signal SYN in the upstream signal S _U is first changed to the logic “1” and then the activation signal ACT is changed to the logic “1” to reduce the power consumption. The suppression is released to enable transmission / reception of information via the information channels B1 and B2 in the upstream signal S _U , and transmission / reception of various control signals via the control channel D.

In the digital subscriber circuit (DLC) 12, the subscriber line test section (TST) 122 has the downlink signal S.
Starting in the _D signals START and extinguishing signal DEACT
Within a predetermined time (for example, 15 seconds) after changing the setting of each to "1".
The synchronization establishment signal SY in the upstream signal S _U transmitted from 31
When it is detected that N has been changed to the logical "1", it is determined that the communication path is normally established via the subscriber line 2,
The start signal START and the deactivating signal DEACT in the downlink signal S _D are set and changed to the logic “0” again.

In the network terminator (NT) 31, the activation signal START and the deactivating signal DEACT in the downlink signal S _D transmitted from the digital subscriber circuit (DLC) 12 are set and changed to logic "0". , The synchronization establishment signal SYN and the activation signal ACT in the upstream signal S _U are respectively set to logic “0”, and information is transmitted / received via the information channels B1 and B2 in the upstream signal S _U again. Transmission and reception of various control signals via the control channel D are stopped to suppress power consumption.

In the digital subscriber circuit (DLC) 12, the subscriber line test unit (TST) 122 sends the synchronization establishment signal SYN and activation signal ACT in the upstream signal S _U transmitted from the network terminating device (NT) 31. When it detects that the setting has been changed to logic "0", the timer circuit (TM)
121 is activated.

The started timer circuit (TM) 121 is
The measurement of the elapsed time is started again, and when a predetermined time (for example, 1 minute) has elapsed, the subscriber line test unit (TS
T) 122 is activated.

The subscriber line test section (TST) 122 is
After changing the setting of the start signal START and the deactivating signal DEACT in the down signal S _D to logic "1" respectively,
If the synchronization establishment signal SYN in the upstream signal S _U transmitted from the network terminating device (NT) 31 is not changed to the logical “1” within a predetermined time (15 seconds in the previous example), It is determined that the communication path has not been normally established via the subscriber line 2, and a failure for the subscriber line 2 is notified to a maintenance device (not shown).

The subscriber line test section (TST) 122 is
When an incoming call or an outgoing call via the subscriber line 2 occurs during activation, the operation is immediately stopped and the digital subscriber circuit (DLC) 12 can execute the call setting operation.

As is apparent from the above description, according to the present embodiment, the timer circuit (TM) 121 periodically (1 in the previous example) in a state where no call is passing through the subscriber line 2.
Start the subscriber line test unit (TST) 122 (in minutes),
The subscriber line test unit (TST) 122 is the digital exchange 1
Since it is confirmed that the communication path is normally established via the subscriber line 2 in the same process as when the incoming call to the subscriber line 2 occurs, the failure occurring in the subscriber line 2 is It is possible to detect the incoming call or outgoing call via the subscriber line 2 without waiting for the occurrence of the incoming call or the outgoing call, and the diagnosis and repair processing can be executed promptly.

It is to be noted that FIGS. 2, 3 and 5 are merely examples of the present invention until now, and the signals flowing through the subscriber line 2 and the timing time are not limited to those shown in the drawings. Although other various modifications are considered, the effect of the present invention does not change in any case. Further, the configuration of the subscriber line accommodation device 100 is not limited to the digital subscriber circuit (DLC) 12 shown in the figure, and many other modifications can be considered. In any case, the effect of the present invention is obtained. does not change. Further, it goes without saying that the configuration of the digital exchange subject to the present invention is not limited to that shown in the drawings.

[0034]

As described above, according to the present invention, in the digital exchange, the normality of the communication path passing through the subscriber line is always confirmed in a state where the call is not set up through the subscriber line. As a result, a failure occurring in the subscriber line can be detected before a call occurs, appropriate diagnosis and repair processing can be performed, and the reliability and maintainability of the digital exchange can be greatly improved.

[Brief description of drawings]

FIG. 1 is a diagram showing the principle of the present invention.

FIG. 2 is a diagram showing a digital exchange according to an embodiment of the present invention.

FIG. 3 is a diagram showing an example of a subscriber line fault monitoring process in FIG.

FIG. 4 is a diagram showing an example of a conventional digital exchange.

5 is a diagram showing an example of a signal flowing through a subscriber line in FIG.

FIG. 6 is a diagram showing an example of a conventional subscriber line fault monitoring process.

[Explanation of symbols]

 1 Digital Switch 2 Subscriber Line 3 Customer's Home 11 Network (NW) 12 Digital Subscriber Circuit (DLC) 13 Central Processing Unit (CP) 14 Digital Subscriber Control Circuit (DLCC) 31, 200 Network Terminator (NT) 32 in-home communication path 33 terminal device (DT) 100 subscriber line accommodation device 101, 201 communication establishing means 102 time limit means 103 subscriber line testing means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nao Koga 3-9-18 Shin-Yokohama, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture Fujitsu Communication Systems Limited (72) Inventor Toshiaki Oishi San-Yokohama, Kohoku-ku, Yokohama-shi, Kanagawa 9-18, Fujitsu Communication Systems Limited (72) Inventor, Sumie Morita 1015 Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Fujitsu Limited

Claims (2)

[Claims] 1. A subscriber line (2) for ISDN which is terminated by a subscriber line accommodation device (100) provided inside the office and a network terminating device (200) provided inside the subscriber premises. When establishing a call via the communication establishment means (101) provided in the subscriber line accommodation device (100)
And a communication establishment means (201) provided in the network terminating device (200) for confirming the normality of a communication path. When the passenger line (2) is in an unused state, the elapsed time is measured,
A time limit means (102) that activates the subscriber line test means (103) every time a predetermined time elapses, and a communication establishment means (101) each time the time limit means (102) activates. When the normality of the subscriber line (2) is confirmed with the communication establishing means (201) in the process of, and the normality of the subscriber line (2) is confirmed, the time limit means (102) A subscriber line fault monitoring system, further comprising: a subscriber line test means (103) for restarting the measurement of the elapsed time. 2. The subscriber line test means (103) immediately stops the operation of confirming the normality of the subscriber line (2) when a call via the subscriber line (2) occurs. The subscriber line fault monitoring system according to claim 1.