JPH11355231A - Multiplexing terminal station equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of an alarm even without masking when not connecting any additional terminal by looping back the corresponding output signal of an auxiliary system interface(I/F) means for main terminal to the input port of the auxiliary system I/F means for main terminal when not connecting any additional terminal. SOLUTION: When an additional terminal 3-1 is disconnected or is not connected from the beginning, it is detected by a control part and a selector 11-1 respectively switches relays 803 and 804 to the side of terminal T and switches relays 703 and 704 to the side of terminal E. Thus, a part time signal (single dotted line) sent from an auxiliary system I/F part 10-1 for main terminal is returned (looped back) to the input port of the auxiliary system I/F part 10-1 for main terminal while keeping the transmission line of a main signal. Thus, the presence of input is continuously detected at the auxiliary system I/F part 10-1 for main terminal and the generation of the alarm caused by input interruption can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multiplexing terminal equipment used in, for example, an optical communication system and having a duplex structure for ensuring reliability.

[0002]

2. Description of the Related Art In an optical communication system requiring high reliability, a multiplexing terminal device and a transmission line are often provided in a duplex configuration in order to avoid a system failure due to a device failure or a transmission line failure.

In this type of duplex system, when the main signal is being transmitted via the working transmission line (that is, normal), the protection transmission line is vacant. Therefore, in order to effectively use the backup transmission line, a multiplexing terminal device that can transmit and receive a signal different from the main signal (hereinafter, referred to as a part-time signal) using the backup transmission line is provided. Have been.

[0004] Such a multiplexing terminal device includes a selection device, and the selection device controls a transmission path of a main signal and a part-time signal. FIG.
1 shows a configuration of a conventional selection device.

In FIG. 6, a main terminal for transmitting and receiving a main signal and an additional terminal for transmitting and receiving a part-time signal are connected to a main terminal working system interface (I / F) via a selection device.
And a backup terminal interface (I / F) for the main terminal. Here, the working I / F for the main terminal and the protection I / F for the main terminal have an interface function for the main terminal, and are both provided inside the multiplexing terminal equipment.

The selection device is a three-terminal relay 701-7.
The transmission path of each signal is switched by switching these relays 701 to 704. In the drawings, N, E, and P are reference numerals assigned to switching terminals of each relay for convenience, N means (Normal), E means (Emergency), and P means (Part-time). .

In a normal state, the relays 701 and 702 are switched to the N side, and the relays 703 and 704 are switched to the P side. As a result, a main signal (solid line in the figure) is exchanged between the working I / F for the main terminal and the main terminal, and a part-time signal is transmitted between the protection I / F for the main terminal and the additional terminal. (Dotted line in the figure) is exchanged. On the other hand, the active I / O for the main terminal
When a fault occurs in the F section, as shown in FIG. 7, each of the relays 701 to 704 is switched to the opposite side, the main signal is guided to the main terminal standby I / F section, and the part time signal is cut off. .

As described above, when a failure occurs in the active system, the main signal is immediately switched to the standby system and rescued, but instead, the part-time signal is disconnected. That is, transmission of a part-time signal is not guaranteed. Due to such circumstances, the additional terminal may not be connected.

However, when the additional terminal is not connected, there is no signal input to the standby I / F section for the main terminal in the normal state of FIG. Is detected, and the multiplexing terminal device enters an alarm state. In order to prevent this, when the additional terminal is not connected, it is necessary to mask the alarm softly. Further, in the standby system switching state shown in FIG. 7, the masking had to be released, and when the state was switched back to the normal state, the masking had to be set again.

As described above, when the additional terminal is not connected, the masking of the alarm must be set / released each time the active / standby system is switched, and the operation is complicated. To make matters worse, if the alarm is masked, even if a fault actually occurs in the backup I / F for the main terminal, it cannot be detected. For this reason, there is no guarantee that information communication can be reliably performed when switching to the standby system.
The significance of duplicating the system will be lost.

In the standby system switching state shown in FIG. 7, since the input and output of the main terminal working I / F section are electrically disconnected, the main terminal working I / F section is left as it is. Even if the repair is completed, the operation check test cannot be performed. For this reason, work such as routing a coaxial cable between the input and output of the working I / F unit for the main terminal has conventionally been required, and the burden on the operator and the labor at the time of installation have been large.

[0012]

As described above, in the conventional multiplexing terminal equipment, when the additional terminal is not connected, the masking of the alarm is set / released every time the active / standby system is switched. And the operation was complicated. In addition, the backup system I / F for the main terminal is masked.
Since a failure of a part cannot be detected, there is no guarantee that a system down can be reliably avoided in the event of a failure in the active system. In addition, a complicated operation is required when performing an operation check test of the main terminal working I / F section, and the burden on the operator and the labor for installation are large.

The present invention has been made in view of the above circumstances,
A first object of the present invention is to provide a multiplexing terminal device which prevents an alarm from being generated even when masking is not performed when an additional terminal is not connected, thereby facilitating operation. It is a second object of the present invention to provide a multiplexing terminal device that can easily perform an operation check test of an active I / F unit for a main terminal.

[0014]

In order to achieve the above object, a first aspect of the present invention is to separate a multiplexed signal transmitted through a high-speed transmission line duplexed into an active system and a standby system into a plurality of channels, A multiplexing terminal device for multiplexing a signal from a low-speed terminal and transmitting the multiplexed signal to the high-speed transmission line, wherein the multiplexing / reception is performed on a signal transmitted through a working high-speed transmission line.
An active system device for performing demultiplexing, and a standby system device for performing multiplexing / demultiplexing on a signal transmitted via a standby high-speed transmission line;
A plurality of main terminal working system interface means provided in the working system device for each of the channels and interfacing with each of the separated signals; and the separation device provided in the protection system device for each of the channels. A plurality of standby interface means for the main terminal for interfacing with each of the received signals, and main terminals for transmitting and receiving the main signal, which are provided according to the respective channels, are connected to each other and transmit and receive a part-time signal. Selecting means for connecting the additional terminals as needed and selectively switching the transmission paths of the main signal and the part-time signal, wherein when the additional terminal is not connected, the corresponding backup interface for the main terminal The output signal of the means
It is characterized in that it is turned back to the input port of the standby interface means for the main terminal.

By taking such means, a signal input is always supplied to the main terminal standby system interface means even when no additional terminal is connected. As a result, a state in which the input is interrupted can be avoided, so that an alarm indicating a failure state is not generated.

Accordingly, since the necessity of masking is eliminated, the trouble associated with the masking can be omitted, and a fault that has actually occurred in the standby interface means for the main terminal can be immediately detected.

Further, the second invention separates a multiplexed signal transmitted via a high-speed transmission line duplexed into an active system and a standby system into a plurality of channels, and multiplexes a signal from a low-speed terminal. A multiplexing terminal device for transmitting to a high-speed transmission line, wherein the multiplexing / demultiplexing is performed on a signal transmitted through the working high-speed transmission line, and the multiplexing / demultiplexing signal is transmitted through the protection high-speed transmission line. A standby system device for performing multiplexing / demultiplexing on signals, a plurality of main terminal active system interface means provided in the active system device according to each of the channels and interfacing with each of the separated signals; A plurality of main terminal spare system interface means provided in the spare system device according to the channel and interfacing with each of the separated signals; provided in accordance with each of the channels; A main terminal for transmitting and receiving a main signal is connected to each other, and an additional terminal for transmitting and receiving a part-time signal is connected as necessary, and a selection path for selectively switching the transmission path of the main signal and the part-time signal is selected. Means for connecting a corresponding main terminal and the main terminal protection system interface means corresponding to the main terminal when a failure occurs in the main terminal working system interface means. An output port and an input port of the working interface means are connected.

By taking such means, the output port and the input port of the active interface means for the main terminal in which the fault has occurred are connected inside the selecting means.
As a result, the transmission test can be performed in a state in which the main terminal working system interface means is incorporated in the apparatus without removing the working interface means from the housing, thereby facilitating operation.

[0019]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a configuration of an optical communication system according to an embodiment of the present invention. This optical communication system is realized, for example, as an international synchronous transmission system. A plurality of multiplexing terminal devices (hereinafter, referred to as nodes) A to F are connected to a duplicated high-speed transmission line 1-0, 1-1.
In the form of a ring. Where 1
-0 indicates the active high-speed transmission line, and 1-1 indicates the standby high-speed transmission line.

The active high-speed transmission line 1-0 transmits a main signal related to ordinary information communication, such as an audio signal and an image signal. The protection system high-speed transmission line 1-1 is used for rescuing the active system high-speed transmission line 1-0, and in a normal state (when there is no failure), information (part-time signal Used to transmit). The part-time signal includes, for example, backup traffic of another system.

Each of the nodes A to F includes, for example, a node A in FIG.
As shown in the figure, the main terminals 2-1 to 2- which exchange the main signal.
n are connected via the main terminal low-speed lines 4-1 to 4-n. If necessary, the additional terminals 3-1 to 3-n for transmitting and receiving part-time signals are connected to the additional terminal low-speed line 5.
These are connected via -1 to 5-n, respectively.

That is, each of the nodes A to F extracts a signal of a predetermined channel from the signals transmitted through the high-speed transmission lines 1-0 and 1-1, and outputs the signals of the low-speed lines 4-1 to 4-n,
Terminals 2-1 to 2-n, 3-1 via 5-1 to 5-n
To 3-n. In addition, each of the terminals 2-1 to 2-n and 3-1 to 3-n is connected to each of the low-speed lines 4-
1 through 4-n, 5-1 through 5-n,
It is multiplexed (added) to a predetermined channel of each high-speed transmission line 1-0, 1-1.

FIG. 2 shows a main configuration of each of the nodes A to F. In other words, each of the nodes A to F has a redundant configuration, and the active device 6-0 is connected via the active high-speed transmission line 1-0, and the standby device 6-1 is connected to the standby high-speed transmission line 1-1. Are connected to adjacent nodes, respectively.

The active system high-speed transmission line 1 is connected to the active system device 6-0.
The higher-order group signal from the adjacent node input via -0 is introduced to the working multiplex / demultiplex unit 8-0 via the working transmission line interface (I / F) unit 7-0. In the working-system demultiplexing unit 8-0, the high-order group signals are separated into low-order group signals for n channels, and the main-terminal working system interface (I / F) units 9-1 to 9-9 provided for each channel. n.

Similarly, in the standby system device 6-1, a higher-order group signal from an adjacent node input via the standby high-speed transmission line 1-1 is transmitted to the standby transmission line interface (I / I).
F) The signal is introduced into the standby multiplexing / demultiplexing unit 8-1 via the unit 7-1 and is separated into low-order group signals for n channels. And
The data is guided to the main terminal standby system interface (I / F) units 10-1 to 10-n provided for each channel.

The low-order group signals output from the main terminal working system I / F sections 9-1 to 9-n are selected by selecting devices 11-1 to 11-n provided corresponding to n channels, respectively. Is input to Similarly, the backup I / F units 10-1 to 10-1 for the main terminal
The low-order group signals output from 0-n are also input to the selection devices 11-1 to 11-n, respectively. That is, each of the selection devices 11-1 to 11-n is provided with the active high-speed transmission line 1 respectively.
−0 and the high-speed transmission line 1 for the standby system.
-1 separated from the low-order group signal.

In the selection devices 11-1 to 11-n, the output destinations of both low-order group signals are selected according to the presence or absence of a failure in the main terminal working I / F units 9-1 to 9-n. You. That is, when there is no failure, the low-order group signals separated from the working high-speed transmission line 1-0 are sent to the main terminals 2-1 to 2-n and the low-order group signals separated from the protection high-speed transmission line 1-1. The next group signal is guided to each of the additional terminals 3-1 to 3-n. When a failure occurs, only low-order group signals separated from the protection system high-speed transmission line 1-1 are guided to the main terminals 2-1 to 2-n.

On the other hand, the low-order group signals transmitted from the main terminals 2-1 to 2-n and the additional terminals 3-1 to 3-n are transmitted to the main terminals by the selectors 11-1 to 11-n. System I / F units 9-1 to 9-n and standby system I / F unit 10-1 for main terminal
To 10-n. Working I / F section 9-1 for main terminal
9-n are multiplexed into higher-order group signals by the working-system multiplexing / demultiplexing unit 8-0 and transmitted to adjacent nodes via the working-system transmission line I / F unit 7-0. Is done. Similarly, the low-order group signals output via the main terminal protection I / F units 10-1 to 10-n are multiplexed into the high-order group signals by the protection system demultiplexing unit 8-1, and the protection system transmission is performed. Road I / F 7-1
Is transmitted to the adjacent node via

Next, the selecting device 1 in each of the nodes A to F
The configuration of 1-1 to 11-n will be described using the selection device 11-1 as an example. FIG. 3 is a diagram showing the configuration. The other selection devices 11-2 to 11-n have the same configuration.

That is, the selecting devices 11-1 to 11-n in the present embodiment are provided with new relays 801 to 804 in addition to the conventional configuration shown in FIGS. Here, the symbol T given to one of the switching terminals of each of the relays 801 to 804 means (Test).

Now, in FIG. 2, the active system devices 6-0,
The control of the standby system device 6-1 and the selection devices 11-1 to 11-n is performed by the control unit 12. The control unit 12 includes, for example, a microcomputer as its main control unit. In addition to known control functions related to channel separation / multiplexing and clock extraction, the control unit 12 includes a loopback control unit 1.
2a.

The loop-back control means 12a is a processing function implemented as software stored in, for example, a program memory, and determines whether there is a failure in the main terminal working I / F sections 9-1 to 9-n. Also, the additional terminals 3-1 to 3-1
-N selection devices 11-1 to 11-
n for controlling the switching state of the relays 701 to 704 and 801 to 804.

Next, the operation in this embodiment will be described with reference to FIG.
This will be described with reference to FIGS. FIG. 3 shows the additional terminal 3-1.
5 shows the switching state of each relay and the flow of signals when the main terminal working system I / F unit 9-1 is connected and there is no failure. That is, in the steady state, the relays 701, 7
02, 801 and 802 have been switched to terminal N,
As a result, a main signal (solid line in the figure) is exchanged between the main terminal 2-1 and the main terminal working I / F unit 9-1. Further, the relays 703 and 704 are switched to the terminal P side,
As a result, a part-time signal is exchanged between the additional terminal 3-1 and the backup I / F unit 10-1 for the main terminal. In addition,
In FIG. 3, the relays 803 and 804 do not participate in the signal flow, and therefore may be connected to any of the terminals E and T.

Now, when the additional terminal 3-1 is removed from this state, or when it is not connected from the beginning,
The control unit 12 detects this fact and sets the switching state of each of the relays 701 to 704 and 801 to 804 in the selection device 11-1 as shown in FIG. That is, the relay 80
3 and 804 are switched to the terminal T side, and the relays 703 and 704 are switched to the terminal E side. As a result, the main signal protection I / F unit 10-1 is maintained while the main signal transmission path is maintained.
The part-time signal (dashed line in the figure) sent from
It is looped back (looped back) to the input port of the backup I / F unit 10-1 for the main terminal.

Thus, the backup I / F section 10 for the main terminal is provided.
In the case of -1, the presence of the input is continuously detected, and it is possible to prevent the occurrence of an alarm due to the disconnection of the input. Next, the main system working I / F section 9-
1, when each of the relays 701 to 704, 8
01 to 804 are switched as shown in FIG. That is, the main unit working I / F unit 9-1 is controlled by the control unit 12.
When a failure is detected in the relays 701 and 7
02, 803, 804, 703, 704 on the terminal E side,
The relays 801 and 802 are switched to the terminal T side. As a result, the main signal (solid line in the figure) is guided from the main terminal 2-1 to the main terminal standby system I / F unit 10-1 to rescue a fault and to use the main terminal active system I / F unit 9 as well. -1 output port and input port are electrically connected.

As a result, while the main signal is rescued from the fault, the signal (two-dot chain line in the figure) output from the main terminal working system I / F unit 9-1 is output from the main unit inside the selection device 11-1. This is returned to the input port of the working I / F unit 9-1 for the terminal. Therefore, the transmission test of the main terminal working I / F unit 9-1 can be performed without having to remove the main terminal working system I / F unit 9-1.

As described above, in the present embodiment, the additional terminal 3
-1 to 3-n are not connected, the standby terminal I /
Selection unit 11-1 selects output signals of F units 10-1 to 10-n
To 11-n, and a backup I / F 1 for the main terminal
The input ports are guided to input ports 0-1 to 10-n.

Because of this, the additional terminals 3-1 to 3-1
−n is not connected, and the backup I / F unit 10 for the main terminal is connected.
In 1 to 10-n, a signal input is always detected. Therefore, an alarm of input disconnection does not occur, and the necessity of masking is eliminated. Thereby, the additional terminal 3-1
It is not necessary to cancel / set the masking of the alarm every time connection / disconnection of .about.3-n is required, and the operation software can be simplified. Further, since the alarm is not masked, the backup I / F unit 10- for the main terminal is used.
When a failure occurs in 1 to 10-n, it can be detected immediately. Thereby, the standby system I for the main terminal
/ F units 10-1 to 10-n are no longer left in a faulty state, and the main system working I / F units 9-1 to 9-n
The main signal can be reliably rescued at the time of active / standby switching due to the failure.

Also, in the present embodiment, the main terminal active system I
At the time of working / spare switching due to a failure of the / F units 9-1 to 9-n, the input ports and output ports of the main terminal working system I / F units 9-1 to 9-n are selected by the selecting devices 11-1 to 11-n. 11-n. With this configuration, the operation test can be performed without removing the main terminal working I / F sections 9-1 to 9-n from the apparatus housing. As a result, it is possible to greatly reduce the labor required for the operation test, which is very convenient.

The present invention is not limited to the above embodiment. For example, in the above-described embodiment, a new relay is incorporated inside the conventional selection device.
A loopback may be performed by adding a switching module to the outside without changing the configuration of the conventional selection device. By doing so, the configuration can be simplified, and a new system can be constructed by utilizing the existing configuration. In addition, various modifications can be made without departing from the spirit of the present invention.

[0041]

As described above in detail, according to the present invention, when the additional terminal is not connected, the output of the main terminal standby system interface means is turned back to the input side of the same main terminal standby system interface means. As a result, it is possible to avoid the occurrence of an alarm indicating that the input has been interrupted, eliminating the need for masking. This eliminates the need for masking each time the active / standby switchover is performed, and makes it possible to immediately detect a failure of the primary terminal standby system interface means, thereby ensuring the rescue of the main signal when the active system fails. Become. Therefore, operational convenience can be achieved.

Further, according to the present invention, when a failure occurs in the working interface means for the main terminal, the input port and the output port of the working interface means for the main terminal are connected. An operation check test of the main terminal active interface means can be easily performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an optical communication system according to an embodiment of the present invention.

FIG. 2 is a diagram showing a main part configuration of each multiplexing terminal device (node) A to F according to the embodiment of the present invention.

FIG. 3 shows a selection device 11- according to the embodiment of the present invention.
The figure which shows the structure of 1-11-n.

FIG. 4 is a diagram illustrating an additional terminal 3 according to the embodiment of the present invention.
The figure which shows the flow of the signal when not connecting 1-3-n.

FIG. 5 is a diagram showing a signal flow when a failure occurs in the main terminal working I / F units 9-1 to 9-n in the embodiment of the present invention.

FIG. 6 is a diagram showing a configuration of a conventional selection device.

FIG. 7 shows a conventional selection device, in which an active system I for a main terminal is used.
FIG. 5 is a diagram showing a signal flow when a failure occurs in the / F section.

[Explanation of symbols]

A to F: nodes (multiplexing terminal equipment) 1-0: working high-speed transmission line 1-1: protection high-speed transmission line 2-1 to 2-n main terminal 4-1 to 4-n main terminal Low-speed line 3-1 to 3-n additional terminal 5-1 to 5-n low-speed line for additional terminal 6-0 working device 6-1 standby device 7-0 working transmission line interface ( I / F) section 8-0: working system demultiplexing section 9-1 to 9-n: working interface for main terminal (I / F)
F) unit 10-1 to 10-n: standby system interface (I / F) unit for main terminal 11-1 to 11-n: selecting device 12: control unit 12a: loopback control means 701 to 704, 801 to 804 …relay

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H04L 12/28 H04L 11/20 C

Claims (2)

[Claims] 1. A multiplexed signal transmitted via a high-speed transmission line duplexed to a working system and a protection system is separated into a plurality of channels, and a signal from a low-speed terminal is multiplexed and transmitted to the high-speed transmission line. A multiplexing terminal device that performs multiplexing / demultiplexing on a signal transmitted through a working high-speed transmission line, and a multiplexing / demultiplexing device related to a signal transmitted via a protection high-speed transmission line. A standby system device for performing separation, a plurality of main terminal working system interface means provided in the working system device in accordance with each of the channels, and interfacing with each of the separated signals; and A plurality of main terminal standby system interface means provided in the standby system device and interfacing with each of the separated signals; and Selection means connected to each of the main terminals for transmitting and receiving the part signals, and additional terminals for performing the transmission and reception of the part-time signals, each of which is connected as necessary, and selectively switching the transmission path of the main signal and the part-time signal. In the multiplexing terminal device comprising: when the additional terminal is not connected, the output signal of the corresponding main terminal standby interface means is looped back to the input port of the main terminal standby interface means. A multiplexing terminal device characterized by the above-mentioned. 2. A multiplexed signal transmitted via a high-speed transmission line duplexed to a working system and a protection system is separated into a plurality of channels, and a signal from a low-speed terminal is multiplexed and transmitted to the high-speed transmission line. A multiplexing terminal device that performs multiplexing / demultiplexing on a signal transmitted through a working high-speed transmission line, and a multiplexing / demultiplexing device related to a signal transmitted via a protection high-speed transmission line. A standby system device for performing separation, a plurality of main terminal working system interface means provided in the working system device in accordance with each of the channels, and interfacing with each of the separated signals; and A plurality of main terminal standby system interface means provided in the standby system device and interfacing with each of the separated signals; and Selection means connected to each of the main terminals for transmitting and receiving the part signals, and additional terminals for performing the transmission and reception of the part-time signals, each of which is connected as necessary, and selectively switching the transmission path of the main signal and the part-time signal. In the multiplexing terminal device comprising: when a failure occurs in the main terminal working system interface means, the corresponding main terminal and the main terminal protection system interface means corresponding to the main terminal are connected and ,
A multiplexing terminal device, wherein an output port and an input port of the working interface means for the main terminal are connected.