JPH06350482A - Transmitter - Google Patents

Abstract

PURPOSE:To reduce the cost of a device by remarkably simplifying the constitution of a control system and to enable a line to be quickly relieved by shortening switching time. CONSTITUTION:The monitor control parts 20, 30, and 40 of a system in current use, when detecting the fault of the system in current use, insert transmission control information to the overhead of a transmission signal advancing a spare transmission line 101 by using switching control information insertion circuits 24, 34, and 44. The monitor control parts 20, 30, and 40 of a downstream system always monitor the overhead of the transmission signal received from an upstream system by using switching control information monitoring circuits 25, 35, and 45, and transfer the switching control information to the downstream system by switching a change-over switch by a time slot when the switching control information is inserted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission device, and more particularly to a standby switching system for a transmission device used for digital communication.

[0002]

2. Description of the Related Art Conventionally, a transmission apparatus is composed of one spare system and N (N is a positive integer) active system, and has a transmission / reception bidirectional spare switching function.
In the case of a large-capacity transmission device, in order to connect a transmission signal of each active system to a backup transmission line, a configuration in which 2-input 1-output selectors provided in each active system are connected in series is widely used. There is.

That is, as shown in FIG. 2, in the case of a transmission apparatus composed of, for example, one spare system and three active systems, the spare transmission lines 101 and 102 are connected to the spare transmission / reception unit 5 of the spare system. The active transmission lines 103 to 108 are connected to the active transceivers 6 to 8 of the active systems, respectively.

Selectors 61, 71 and 81, overhead insertion circuits 62, 72 and 82 for working signals and overhead termination circuits 63 and 7 are provided in the working transceivers 6 to 8, respectively.
3 and 83 are mounted.

Each of the selector sections 61, 71, 81 comprises a transmission direction changeover switch (2-input 1-output selector), a reception direction signal branch circuit, and a reception-direction changeover switch (2-input 1 output selector).

Depending on which side of the standby transmission line 101 and the working transmission lines 103, 105, 107 the changeover switch in the transmission direction of each of the selectors 61, 71, 81 is switched, that is, depending on the combination of the switching states. ,
The working signal connected to the backup transmission line 101 is determined.

Further, the selector switches in the receiving directions of the selector sections 61, 71, 81 either receive the signals of the backup transmission line 101 by the active transmission / reception sections 6-8, or the signals of the active transmission channels 104, 106, 108. Is to decide what to receive.

The standby switching control unit 9 collects the reception status of each transmission line and the in-device monitoring results of the standby system and the working system, and detects an abnormality in the received signal and an in-device monitoring result error.

When the standby switching control unit 9 detects an abnormality in the working system, it inserts switching control information into the overhead of the backup transmission line transmission signal in the main signal, so that each working transmission line 103 to
The opposite device (not shown) connected to 108 is requested to connect the working signal to the backup transmission lines 101 and 102 (opposite device connection request).

The backup switching control unit 9 is inserted into the overhead of the backup transmission line transmission signal and confirms the connection with the remote device by monitoring the switching control information sent from the remote device. Switch the receiving direction changeover switch of ~ 8.

At the same time, the spare switching control unit 9 switches the changeover switch in the transmission direction and sends the connection information to the spare transmission line 10.
It is transmitted to the opposite device by using the overhead of the main signal of 1. Upon confirming this connection information, the opposite device switches the reception direction changeover switch of the own device to complete the bidirectional changeover control.

When the switching request from the opposite device and the failure of the self apparatus occur at the same time, or when a plurality of failures occur in the apparatus, the standby switching control unit 9 judges their priorities. , Switching control is executed according to the switching request having the highest priority.

SDH (Synchronous D
digital Hierarchy) transmission device, K
The 2-byte overhead of 1 and K2 is allocated for switching control, and is recommended by CCITT G. 783 defines the bit assignment and control sequence.

[0014]

In the conventional backup switching control system described above, one backup switching control unit in the device collects the transmission path and the in-device monitoring result for the backup system and all the active systems, Based on the collected information, the execution of the switching control is determined, each switching switch is controlled, and the insertion and termination of the switching control information in the overhead of the main signal are collectively controlled.

In a large-scale transmission device, the range for collecting information is wide, and the changeover switches to be controlled are often dispersed in a large number of packages. Therefore, changeover triggers (fault information) are collected, and their judgment and switching are performed. In order to control the switch, a complicated control circuit that covers the entire device is required,
There is a problem that the device becomes expensive.

Further, collection of switching triggers (fault information),
Since it takes a lot of time for the determination and the control of the changeover switch, there is a problem that the changeover time is increased and it is difficult to quickly rescue the line.

Therefore, the object of the present invention is to solve the above-mentioned problems, to greatly simplify the structure of the control system, to reduce the cost of the apparatus, and to shorten the switching time and speed up the operation. It is to provide a transmission device capable of line relief.

[0018]

A transmission device according to the present invention comprises a backup circuit connected to a backup transmission line and a transmission circuit connected in series to each of the backup transmission lines and connected to its own circuit. A transmission device including N (N is a positive integer) switching circuits for switching between a protection line and the spare transmission line, the transmission device being provided in each of the spare circuit and the N switching circuits and corresponding to its own circuit. And a monitoring means for monitoring the inside of the transmission line and the inside of the circuit, and a transmission request which is provided in each of the N switching circuits and which transmits a request for switching the transmission line corresponding to the own circuit to the backup transmission line to a circuit in the subsequent stage Means for detecting the switching request from the circuit at the preceding stage, and N for each of the N switching circuits,
The control means controls to switch between the transmission path connected to the own circuit and the backup transmission path according to the monitoring result of the monitoring means and the detection result of the detecting means.

[0019]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In the figure, a transmission apparatus according to an embodiment of the present invention is composed of one standby system and three active systems.

The backup transmission / reception unit 1 of the backup system is connected to backup transmission lines 101 and 102, and the active transmission / reception units 2 to 4 of each active system are connected to active transmission lines 103 to 108, respectively.

Each of the active transmitter / receivers 2 to 4 has a selector unit 21, 31, 41, an overhead insertion circuit 22, 32, 42 for an active system signal, and an overhead termination circuit 23, 3 respectively.
3, 43 and are mounted.

The selector units 21, 31, 41 are each a transmission direction changeover switch (2-input 1-output selector), a reception direction signal branch circuit, a reception-direction changeover switch (2-input 1-output selector), and changeover control. Information insertion circuit 24, 3
4, 44 and switching control information monitor circuits 25, 26, 3
5,36,45,46.

Depending on which side of the standby transmission line 101 and the active transmission lines 103, 105, 107 the changeover switch in the transmission direction of each of the selectors 21, 31, 41 is switched, that is, depending on the combination of the switching states. ,
The working signal connected to the backup transmission line 101 is determined.

The selector switches in the receiving directions of the selectors 21, 31, 41 receive the signals of the backup transmission line 101 from the active transmission / reception units 2-4, or the signals of the active transmission lines 104, 106, 108. Is to decide what to receive.

The standby transmission / reception unit 1 and the active transmission / reception units 2 to 4 are equipped with independent monitoring control units 10, 20, 30, 40, respectively.
0 monitors each transmission line and monitors the insides of the standby system and the working system.

Monitoring and control units 20, 30, 40 of a certain working system
Detects a failure of the active system (abnormal reception signal or abnormal monitoring result in device), the monitoring control unit 2
0, 30, 40 are switching control information insertion circuits 24, 34, 4
4 is used to insert the switching control information into the overhead of the transmission signal going to the backup transmission line 101.

Downstream system (spare transmission lines 101, 10
The monitoring control units 20, 30, and 40 of the system close to 2 use the switching control information monitor circuits 25, 35, and 45 to overhead the transmission signal received from the upstream system (the system far from the backup transmission lines 101 and 102). Is constantly monitored.

When the switching control information is inserted in the overhead of this transmission signal, the monitoring control units 20, 30, 40
Switches the changeover switch at that time slot and transfers the changeover control information to the downstream system.

As a result, each working transmission line 103 to 10
8 to the opposite device (not shown) connected to the backup signal transmission line 10 of the working signal from the system in which the failure has occurred.
A connection request to 1, 102 is made.

On the other hand, the supervisory control units 20, 30, 40 confirm the connection with the opposite device by monitoring the switching control information inserted in the overhead of the transmission signal received from the backup transmission line 102, and then the active transmission / reception. Change the receiving direction changeover switch of the units 2 to 4.

At the same time, the supervisory control units 20, 30, 40 switch the transmission direction changeover switch to transmit the connection information to the opposite device by using the overhead of the main signal toward the backup transmission line 101. Upon confirming this connection information, the opposite device switches the reception direction changeover switch of the own device to complete the bidirectional changeover control.

When the switching request from the opposite device and the failure of the own system occur at the same time, the monitoring control units 20, 3
0 and 40 determine the priority and execute switching control according to the switching request having the highest priority.

When a plurality of active systems have a failure, the supervisory control units 20, 30, 40 of each active system.
Rewrites the overhead switching control information of the main signal according to the priority of the switching request so that the switching request with the highest priority is transmitted to the opposite device.

For example, if a failure occurs in the active transmitter / receiver units 2 and 3 at the same time, first, the monitoring control unit 30 of the active transmitter / receiver unit 3 is started.
Uses the switching control information insertion circuit 34 of the selector unit 31 to insert the switching control information into the overhead of the transmission signal going to the backup transmission path 101 and send it to the selector unit 21 of the active transmission / reception unit 2.

In the active transmission / reception unit 2, the selector unit 21
When the switching control information monitor circuit 25 of 1 detects that the switching control information is inserted in the overhead of the transmission signal from the active transmission / reception unit 3, the monitoring control unit 20 causes the active transmission / reception unit 3 to operate.
And the switching control information of its own system are compared.

When the switching control information of the own system has a higher priority than the switching control information of the active transmission / reception unit 3, the supervisory control unit 20 inserts the active transmission / reception unit inserted in the overhead of the transmission signal toward the backup transmission line 101. The switching control information of No. 3 is rewritten to the switching control information of the own system.

Further, when the switching control information of the active transmission / reception unit 3 has a higher priority than the switching control information of its own system, the supervisory control unit 20 inserts the active signal inserted in the overhead of the transmission signal toward the backup transmission line 101. The switching control information of the transmission / reception unit 3 is sent to the standby transmission / reception unit 1 without being rewritten.

Therefore, in the overhead of the transmission signal sent from the spare transmission / reception unit 1 to the spare transmission line 101, the connection request with the highest priority is set until the spare transmission line 101 is reached.

As described above, the three supervisory control units 20, 30, 40 corresponding to the respective active systems are dispersedly arranged in the apparatus, and the supervisory control units 20, 30, 40 correspond to the active system transmission lines. 103-108 and the inside of the device are monitored, and by controlling the changeover switches of the respective selector units 21, 31, 41, and by controlling the insertion and termination of the changeover control information defined in the overhead of the main signal. As in the prior art, a switching control unit that collects failure information from the entire apparatus and performs comprehensive determination and processing regarding execution of switching becomes unnecessary.

Therefore, the configuration of the control system in a large-scale transmission device can be greatly simplified, and the device design and manufacturing cost can be reduced. Further, the collection range of the changeover trigger (fault information) is narrowed, the changeover switch can be easily controlled, the processing time can be shortened, and quick line rescue can be performed.

[0042]

As described above, according to the present invention, each of the N switching circuits for switching between the transmission line connected to the own circuit and the backup transmission line is provided with the transmission line and the circuit corresponding to the own circuit. A monitoring means for monitoring, a sending means for sending a request for switching the transmission path corresponding to the own circuit to the backup transmission path to a circuit in a subsequent stage, and a detecting means for detecting a switching request from the circuit in the preceding stage,
The configuration of the control system is greatly simplified by including control means for controlling switching between the transmission path connected to the own circuit and the backup transmission path according to the monitoring result of the monitoring means and the detection result of the detection means. Therefore, there is an effect that the cost of the device can be reduced, and the switching time can be shortened to enable quick line relief.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional example.

[Explanation of symbols]

1 standby transmission / reception circuit 2-4 active transmission / reception circuit 10, 20, 30, 40 monitoring control unit 21, 31, 41 selector unit 22, 32, 42 overhead insertion circuit 23, 33, 43 overhead termination circuit 24, 34, 44 switching control Information insertion circuit 25, 26, 35, 36, 45, 46 Switching control information monitor circuit 101, 102 Backup transmission line 103-108 Working transmission line

Claims (3)

[Claims] 1. A backup circuit connected to a backup transmission line,
A transmission apparatus including N (N is a positive integer) switching circuits for switching between the transmission lines connected to the spare transmission line in series with each other and connected to the own circuit and the spare transmission line. And a monitoring unit provided in each of the backup circuit and the N switching circuits, for monitoring the transmission line corresponding to the own circuit and the inside of the circuit, and provided in each of the N switching circuits.
Sending means for sending a request for switching the transmission path corresponding to the own circuit to the backup transmission path to a circuit at a subsequent stage, and N switching circuits provided in each of the N switching circuits and detecting the switching request from the circuit at the previous stage. And a switching means provided in each of the N switching circuits for switching between the transmission path connected to the own circuit and the backup transmission path according to the monitoring result of the monitoring means and the detection result of the detecting means. A transmission device having control means for controlling. 2. The control means is configured to perform a switching control according to a preset priority when a competition of the switching requests is detected from the monitoring result of the monitoring means and the detection result of the detecting means. The transmission device according to claim 1, wherein: 3. The sending means is configured to send the switching request by inserting it into the overhead of the main signal to the spare circuit, and the detecting means, the detecting means being the main signal from the circuit at the preceding stage to the spare circuit. 3. The transmission device according to claim 1 or 2, wherein the switching request inserted in the overhead of is detected.