JPH07202991A - Digital line switching system - Google Patents

Abstract

PURPOSE:To discriminate the digital lines of an active system and a standby system from the side of the digital lines by disconnecting the digital line of the standby system on the side of the digital line. CONSTITUTION:This system is provided with an administration report transmitting means 10 in a terminal 1, a line disconnecting means 30 in a line connector 3, and digital transmission lines 2-1 to 2-3. Thus, respective terminals 1-1 and 1-2 are provided with the administration report transmitting means 10 for transmitting an operational report showing the operation and nonoperation for each connected digital line, and line connectors 3-1a, 3-1b, 3-2a and 3-2b arranged in the digital lines are provided with the line interrupting means 30 for recognizing the administration reports transmitted from the administration report transmitting means 10 of the terminals 1-1 and 1-2 and interrupting the digital line decided as non-administration. Then, the digital line of the standby system is recognized and interrupted by the line connectors 3-1a, 3-1b, 3-2a and 3-2b based on the operational reports transmitted from the terminals 1-1 and 1-2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital line switching system for switching a plurality of digital lines set between terminals.

[0002]

2. Description of the Related Art FIG. 11 shows a basic configuration of a digital line transmission system. In the figure, the output signal of the terminal 1-1 is the digital transmission line 2-1, the line connection device 3-1, the digital transmission line 2-2, the line connection device 3-2, the digital transmission line 2-3, the line connection device. It is transmitted to the opposite terminal 1-2 via the digital transmission path 2-4. The same applies to the opposite direction.

The terminal 1-1 and the terminal 1 configured as described above
The two-way transmission line between -2 is called a digital line. In the example shown here, two lines of digital lines are provided as shown by adding a and b to each symbol, and one of them is selected by the line switching means provided in each terminal. As a result, even if a failure occurs in the active digital line, communication can be continued by switching to the other system. Also, a test involving disconnection of the digital line can be easily performed by switching the operation system to the non-test side.

[0004]

However, in the conventional digital line transmission system, it is not possible to discriminate the digital line currently in operation from the digital line side. Therefore, when performing a test that involves disconnection of the digital line, the operator of the digital line inquires of the terminal operator which digital line is the operating system, and if necessary the terminal I had to ask the operator to switch the operating system.

The present invention addresses such a problem, and is capable of discriminating an active digital line from the digital line side and switching the active digital line from the digital line side. The purpose is to provide a scheme.

[0006]

According to a first aspect of the present invention, in a digital line switching system for switching a plurality of digital lines set between terminals having line switching means, each terminal is connected. The operation notification transmitting means for transmitting operation notification indicating operation or non-operation for each digital line is provided, and the line connection device arranged in the digital line recognizes the operation notification transmitted from the operation notification transmitting means of the terminal. However, it is provided with a line disconnecting means for disconnecting the non-operating digital line.

According to a second aspect of the present invention, in a digital line switching system for switching a plurality of digital lines set between terminals having line switching means, each terminal operates for each connected digital line. Or equipped with operation notification recognition means for recognizing operation notification indicating non-operation,
The line connection device arranged in the digital line is provided with an operation notification sending unit for sending an operation notification indicating the operation or non-operation to the connected digital line and a line cutoff unit for cutting off the non-operational digital line. Prepare

[0008]

In the digital line switching system according to the first aspect, the line connection device recognizes the non-operational digital line based on the operation notification sent from the terminal, and cuts off the digital line. Further, in the digital line switching system according to the second aspect, the line connection device determines the working and non-working digital lines, notifies the terminal, and disconnects the non-working digital line. As a result, it is possible to distinguish the working and non-working digital lines from the digital line side. Further, since the non-operation system digital line is cut off, the operator of the digital line can perform a test involving disconnection of the digital line without confirming the operating state of the digital line on the terminal side. .

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a first basic configuration of a digital line transmission system according to claim 1. The features of the present invention are:
The terminal 1 is provided with the operation notification transmitting means 10, and the line connection device 3
In addition, the circuit breaker 30 is provided. Here, the terminal 1 including the operation notification transmitting means 10 and the line disconnecting means 3
The configuration of each embodiment of the line connecting device 3 including 0 is shown in FIGS. 2 and 3. 2-1, 2-2, 2-3 are digital transmission lines, 3-1 and 3-2 are line connection devices, and digital lines of each system are distinguished by a and b.

In FIG. 2, the terminal 1 recognizes the frame termination section 11 and the frame generation section 12 connected to the digital line (digital transmission line 2-1) and the failure information sent from the line connection device 3 to detect a failure. Information recognition unit 13
And an operation notification recognizing unit 14 for recognizing an operation notification sent from the opposite terminal, and an operation notification sending unit 15 for sending an operation notification to the line connection device 3 and the opposite terminal, two systems corresponding to each digital line. (Distinguished by a and b in the figure).
Further, a digital line for transmitting a main signal is selected based on the information of the failure information recognition unit 13 and the operation notification recognition unit 14 of each system, and an operation notification is sent to the operation notification sending unit 15 corresponding to the digital line. At the same time, the control circuit 1 for controlling the switching of the line switching means 16 for switching the main signal.
7 is provided. The failure information recognition unit 13, the operation notification recognition unit 14, the operation notification transmission unit 15, and the control circuit 17 constitute the operation notification transmission unit 10.

In FIG. 3, the line connection device 3 includes frame terminating units 31 and 32 connected to input terminals and frame generating units 33 and 34 connected to output terminals.
And the operation notification recognition unit 3 connected to the frame termination unit 31.
5, the operation notification recognition unit 36 connected to the frame termination unit 32, the control circuit 37 connected to the operation notification recognition units 35 and 36, and the frame termination unit 3 under the control of the control circuit 37.
The circuit breaker circuit 38 blocks the main signal from the frame generator 33 to the frame generator 33, and the circuit breaker circuit 39 blocks the main signal from the frame terminal 32 to the frame generator 34 under the control of the control circuit 37. . The operation notification recognition units 35, 36, the control circuit 37, and the line disconnection circuit 3
The line breaker 30 is composed of 8, 39.

The line switching operation in this embodiment will be described below with reference to FIGS. The control circuit 17 of the terminal 1 monitors the failure state of each digital line via the failure information recognition units 13a and 13b, and the operation notification recognition unit 14
The opposite terminal recognizes the digital line currently selected as the active system via a and 14b. Here, the control circuit 1
If one of the digital lines is out of order, 7 designates the digital line of the system not out of order as the active system, and 2
If both lines are normal, the digital line selected by the remote terminal as the active system is designated as the active system. Then, the operation notification sending unit 15 corresponding to the digital line designated as the operation system is controlled to send the operation notification via the frame generation unit 12. On the other hand, the operation notification is not sent to the non-operational digital line.

When the terminal 1 does not know the failure of the digital line and does not know the status of the opposite terminal and autonomously selects the digital line to be the active system, the failure information recognition unit 13 and the operation The notification recognition unit 14 is unnecessary.

Frame termination units 31, 3 of the line connection device 3
Reference numeral 2 processes the input signal of the input terminal, and the operation notification recognition units 35 and 36 recognize the operation notification sent from the terminal. The control circuit 37 determines whether to send the main signal (data) to the output terminal, depending on the presence or absence of the operation notification. That is, when the operation notification is received, the line interruption circuits 38 and 39 are not operated, and when the operation notification is not received, the line interruption circuits 38 and 39 are operated to interrupt the main signal.

The operation notification is sent to the terminal 1 separately from the main signal.
Is transmitted to each line connection device 3. To this end, a transmission line dedicated to operation notification is provided, or a method of multiplexing and transmitting to a main signal is adopted.

As described above, each line connection device 3 can cut off the digital line that is the non-operation system based on the operation notification transmitted from the terminal 1. As a result, it becomes possible to easily identify the working system or the non-working system from the digital line side. In this embodiment, the control circuit 37 of each line connection device determines whether or not to disconnect the digital line, but all line connection devices may share one control circuit. A second basic configuration corresponding to this is shown in FIG. 4, and an example configuration of the line connection device is shown in FIG. As shown here, a communication circuit 41 is arranged in place of the control circuit 37 of each line connection device,
The communication circuit 41 is connected to the control circuit 42 via a communication line.

The operating conditions of the line disconnecting circuits 38 and 39 in the line connecting device 3 will be described with reference to Tables 1 to 4.

[0018]

[Table 1] The operating conditions shown in Table 1 are from the bidirectional input terminals,
That is, the main signal is transmitted without operating both of the line disconnecting circuits 38 and 39 only when the operation notifications are received from both terminals facing each other. In other cases, that is, when at least one of the terminals does not send an operation notification,
The digital circuit of the system is set as a non-operation system, and both the circuit interruption circuits 38 and 39 are operated to interrupt the main signal.

[0019]

[Table 2] The operating conditions shown in Table 2 are the line disconnecting circuit on the side that receives the operation notification, that is, the line disconnecting circuit 38 when the operation notification is received from the input terminal, and the line disconnecting circuit when the operation notification is received from the input terminal. The main signal is transmitted without operating 39. On the other hand, the line disconnecting circuit on the side not receiving the operation notification, that is, the line disconnecting circuit 38 is activated when the operation notification is not received from the input terminal, and the line disconnecting circuit 39 is activated when the operation notification is not received from the input terminal. Shut off the main signal. The operation notification under such operating conditions becomes a control signal for the terminal to transmit the main signal.

[0020]

[Table 3] The operating conditions shown in Table 3 are the line disconnecting circuit on the side opposite to the side receiving the operation notification, that is, the line disconnecting circuit 39 when the operation notification is received from the input terminal, and the operation notification when the operation notification is received from the input terminal. The main signal is transmitted without operating the line break circuit 38. On the other hand, the line blocking circuit on the side opposite to the side not receiving the operation notification, that is, the line blocking circuit 39 when the operation notification is not received from the input terminal, and the line blocking circuit 38 when the operation notification is not received from the input terminal To shut off the main signal. The operation notification under such operating conditions becomes a control signal for receiving the main signal transmitted from the opposite terminal.

[0021]

[Table 4] The operating conditions shown in Table 4 are that, when an operation notification is received from either one of the input terminals, that is, from either of the opposite terminals, both of the line interruption circuits 38 and 39 are not activated and the main signal is output. Transmission. In other cases, that is, only when the operation notifications are not sent from both terminals, the digital circuit of the system is set as the non-operation system and both the circuit interruption circuits 38 and 39 are operated to interrupt the main signal.

FIG. 6 shows a first basic configuration of the digital line transmission system according to the second aspect. The feature of the present invention is that the terminal 1 is provided with the operation notification recognition means 50, and the line connection device 3 is provided with the operation notification transmission means 60 and the line disconnection means 70. Here, the terminal 1 including the operation notification recognizing means 50, the operation notification transmitting means 60, and the line disconnecting means 7
The configuration of each embodiment of the line connection device 3 including 0 is shown in FIGS. 7 and 8.

In FIG. 7, the terminal 1 recognizes the frame termination section 11 and the frame generation section 12 connected to the digital line (digital transmission line 2-1) and the failure information sent from the line connection device 3 to detect a failure. Information recognition unit 51
And an operation notification recognizing unit 52 for recognizing an operation notification sent from the line connection device 3 corresponding to each digital line.
A system is provided (distinguished by a and b in the figure). Further, a control circuit 53 for selecting a digital line for transmitting a main signal based on the information of the failure information recognizing unit 51 and the operation notification recognizing unit 52 of each system and performing switching control of the line switching means 16 for switching the main signal. Prepare The failure information recognition unit 51, the operation notification recognition unit 52, and the control circuit 53 constitute an operation notification recognition unit 50.

In FIG. 8, the line connection device 3 includes frame terminating units 31 and 32 connected to input terminals and frame generating units 33 and 34 connected to output terminals.
And the failure state recognition unit 6 connected to the frame termination unit 31.
1, a failure state recognition unit 62 connected to the frame terminating unit 32, a communication circuit 63 connected to the failure state recognition units 61 and 62, and a control circuit 64 shared by each line connection device connected to the communication circuit 63. An operation notification sending unit 65, 66 for sending an operation notification under the control of the control circuit 64;
4. The line blocking circuit 38 for blocking the main signal from the frame terminating unit 31 to the frame generating unit 33 under the control of 4 and the line blocking for blocking the main signal from the frame terminating unit 32 to the frame generating unit 34 under the control of the control circuit 64. And a circuit 39. The failure state recognition units 61 and 62, the communication circuit 63, the control circuit 64, and the operation notification transmission units 65 and 6
The operation notification sending means 60 is constituted by 6. Further, the communication circuit 63, the control circuit 64, and the line cutoff circuits 38, 3
The line disconnecting means 70 is constituted by 9.

The line switching operation in this embodiment will be described below with reference to FIGS. 6 to 8. The frame termination units 31 and 32 of the line connection device 3 process the input signals of the input terminals, and the failure state recognition units 61 and 62 determine whether or not there is a failure state. The result is transferred to the control circuit 64 via the communication circuit 63. The control circuit 64 collects failure information from all the line connection devices 3, selects a digital line in which no failure has occurred, and notifies the line connection device of the digital line. The operation notification sending units 65 and 66 of the line connection devices, which are set to the operating system, send the operation notifications through the frame generation units 33 and 34. On the other hand, the line connection device of the digital line that has become the non-operation system does not send the operation notification. Further, the control circuit 64 does not operate the line disconnecting circuits 38 and 39 of the line connecting device that is the operating system, but operates the line disconnecting circuits 38 and 39 of the line connecting device that is the non-operating system to block the main signal. .

The control circuit 53 of the terminal 1 recognizes the operation notice sent from the line connection device of the digital line which is the operation system through the operation notice recognizing units 52a and 52b, and thereafter, sets the digital line as the operation system. Treat it and recognize the other digital line as a non-operation system. The operation notification is transmitted from each line connection device 3 to the terminal 1 separately from the main signal. To do this, provide a dedicated transmission line for operation notification, or
A method of multiplexing and transmitting to the main signal is adopted.

As described above, in each line connection device 3, it is possible to determine the digital line to be the active system in accordance with the line state and to cut off the digital line to be the non-operation system.
As a result, it becomes possible to easily identify the working system or the non-working system from the digital line side.

In this embodiment, the control circuit 64 shared by each line connection device determines the digital line to be the active system or the non-operation system, but each line connection device has its own control circuit. Can be A second basic configuration corresponding to this is shown in FIG. 9, and an example configuration of the line connection device is shown in FIG. As shown here, instead of the communication circuit 63 of each line connection device, the control circuit 6
7 is arranged, but it is necessary to exchange the failure information recognized by the control circuit 67 of each line connection device. For that purpose, a communication line for connecting all the control circuits 67 is provided, or as shown in FIG. 9, failure information is multiplexed with a main signal and transmitted between the same lines, and communication is performed only between the line connection devices at each point. Set up a line.

[0029]

As described above, in the digital line switching system of the present invention, the non-operating digital line is cut off on the digital line side. As a result, the digital line side can discriminate the working and non-working type digital lines, and the operator of the digital line can disconnect the digital line without checking the operating state of the digital line on the terminal side. It is possible to perform various tests.

[Brief description of drawings]

FIG. 1 is a diagram showing a first basic configuration of a digital line transmission system according to claim 1.

FIG. 2 is a diagram showing a configuration of an embodiment of a terminal 1 in the first basic configuration.

FIG. 3 is a diagram showing a configuration of an embodiment of the line connection device 3 in the first basic configuration.

FIG. 4 is a diagram showing a second basic configuration of the digital line transmission system according to claim 1;

FIG. 5 is a diagram showing an example configuration of a line connecting device 3 in a second basic configuration.

FIG. 6 is a diagram showing a first basic configuration of the digital line transmission system according to claim 2;

FIG. 7 is a diagram showing an example configuration of the terminal 1 in the first basic configuration.

FIG. 8 is a diagram showing a configuration of an embodiment of the line connection device 3 in the first basic configuration.

FIG. 9 is a diagram showing a second basic configuration of the digital line transmission system according to claim 2;

FIG. 10 is a diagram showing a configuration of an embodiment of the line connection device 3 in the second basic configuration.

FIG. 11 is a diagram showing a basic configuration of a digital line transmission system.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 terminal 2 digital transmission line 3 line connection device 10 operation notification transmission means 11 frame termination section 12 frame generation section 13 failure information recognition section 14 operation notification recognition section 15 operation notification transmission section 16 line switching means 17 control circuit 30 line disconnection means 31 , 32 Frame terminating unit 33, 34 Frame generating unit 35, 36 Operation notification recognizing unit 37 Control circuit 38, 39 Line disconnecting circuit 41 Communication circuit 42 Control circuit 50 Operation notification recognizing means 51 Failure information recognizing unit 52 Operation notification recognizing unit 53 Control Circuit 60 Operation notification sending means 61, 62 Failure state recognition section 63 Communication circuit 64 Control circuit 65, 66 Operation notification sending section 67 Control circuit 70 Line disconnecting means

Claims (2)

[Claims] 1. A digital line switching system for switching a plurality of digital lines set between terminals having a line switching means, wherein each terminal is provided with an operation notification indicating operation or non-operation for each connected digital line. And a line connection device arranged in the digital line,
A digital line switching system comprising: a line disconnecting unit that recognizes an operation notification transmitted from an operation notification transmitting unit of the terminal and disconnects an inoperative digital line. 2. In a digital line switching system for switching a plurality of digital lines set between terminals having line switching means, each terminal is provided with an operation notification indicating operation or non-operation for each connected digital line. Is provided with an operation notification recognizing means, the line connection device arranged in the digital line,
A digital line switching system comprising: an operation notice sending unit for sending an operation notice indicating operation or non-operation to the connected digital line; and a line cutoff unit for cutting off the non-operational digital line.