JPS6115444A - Loopback control system - Google Patents

Abstract

PURPOSE:To stabilize the system while holding the loopback constitution by transmitting a constitution holding signal from a central station device to each terminal station when single loop reconstitution is made by a terminal loopback control due to both terminal station system-down. CONSTITUTION:If both systems of terminal stations TDS2 are in system-down, both adjacent stations detect a fault of optical reception, apply loopback control then the system is subject to a reconstitution loopback by a system control section SYS to constitute a stable single loop as shown in broken lines. The system control section SYS transmits the constitution holding signal to a specific control channel on both system optical loops via central control sections CSCTL0, CSCTL1 to keep stably the loopback constitution, thereby preventing the effect of temporary restoration.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a ring optical communication network that connects a central office device and a plurality of distributed end station devices depending thereon, and particularly relates to a double loop optical communication network. This invention relates to a system reconfiguration loopback control method when optical power is down on both terminal stations in a communication network.

[Prior art]

Conventionally, in this type of ring optical communication network, when a certain terminal station's optical system goes down, the 0 system and 1 system loops run in opposite directions. is not received. The terminal station that detects an optical synchronization error and detects a 1-system loose optical reception abnormality in hardware branches the light transmission side of the 0-system loop and sends the 0-system loose light to the 1-system loose.
The terminal station that detects an optical reception abnormality in the 0-system loop performs loopback control to branch the transmission side of the 1-system loop and send out the loose light of the 1-system to the 0-system loop. In this way, the system control unit monitors and controls both loops within the central office equipment.

When both systems of a certain terminal station are optically down, the terminal station performs loopback control and performs loopback reconfiguration control of the entire optical transmission line configured as a single loop.

[Problem that the invention seeks to solve]

Therefore, there is no problem if a certain terminal station's optical system goes down continuously, but it becomes a problem when that terminal station automatically goes down and recovers repeatedly. In other words, the terminal stations on both sides of the failed terminal station.

When light is received normally, the loopback is canceled and the loop returns to the normal loop immediately. If light is received abnormally immediately thereafter, the loopback operation is performed. As a result, the abnormal operation of the faulty terminal station constantly affects all the terminal stations through repeated abnormal operations, resulting in a drawback in stable operation after the reconfiguration control operation.

The present invention provides a configuration maintenance signal (hereinafter referred to as HOL
The present invention attempts to provide a control method that solves the above-mentioned drawbacks by transmitting a signal (referred to as a D signal) and preventing the loopback configuration from being canceled immediately even after the optical reception abnormality that is the cause of the loopback configuration is restored. be.

[Means and effects for solving the problems] In the present invention,
A central office device that monitors and controls the entire optical communication network and a plurality of terminal devices that monitor and control the accommodated terminal lines are distributed, and these central office devices and terminal devices have a redundant configuration of 0 system and 1 system, respectively. When the optical system of both terminal stations goes down in a 92-way loop transmission line, the hardware control of the terminal station performs a loopback operation when the optical reception is abnormal, and the system control unit in the central station equipment performs a loopback operation using the loopback operation. Bank reconfiguration control is performed, but in order to prevent abnormal operation of the failed terminal station from affecting loopback reconfiguration, the system control unit sends a HOLD signal to both loops using a specific control channel. , HOLD until the failed terminal station is completely restored.
The signal is configured to maintain loopback operation of the end station.

〔Example〕

Next, nine embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram of the entire optical loop communication network according to the present invention, and includes a system control unit sys that monitors and controls the entire optical loop in both systems within the central station CS.

0 system central control unit C3CTL0. 1 system central control unit C5C
TL 1 and a plurality of terminal stations TDS1°TDS2 . 0 system terminal station control unit TDS I in TDS3
C.T.L.O.

TDS2CTLO, TDS5CTL0. 1 system terminal station control unit TDSICTLl, TDS2CTL1. TDS
3CTL1 is connected by an optical transmission line (0 system loop) 4 and (1 system loop) 5 as a double loop in opposite directions.

FIG. 2 shows an example when a certain terminal station (TDS2 in this case) has both optical systems down. As shown in the figure, in the terminal stations on both sides of the faulty terminal station TDS2, the terminal station control unit TDS CTL detects an optical reception abnormality and performs a loopback operation, and then the system control unit SYS performs reconfiguration loopback control, and the central Control unit C3CTLO.

A bypass or loopback instruction is given to C3CTL1 so as to form a stable-heavy loop as shown by the broken line.

Conventionally, as shown in Figure 3 (,), when a faulty terminal station (terminal station with optical down on both systems) repeatedly goes down and recovers due to abnormal operation, the loop badge operation and normal operation are repeated to other normal terminal stations. It had a big influence. Therefore, after being reconfigured and looped back as shown in the right diagram of Fig. 3(a), the system control unit SYS sends a HOLD signal to a specific control channel on both optical loops via the central control units C3CTLO and C3CTL1. Send and keep loopback operation intact.

This allows the reconfiguration loopback state to remain stable even when the faulty terminal station operates abnormally. The HOLD signal sent from the central station CS is controlled by the terminal station and instructs the terminal station loopback control section on the other side to maintain the configuration.

FIG. 4 shows a configuration diagram of a terminal station (TDSL in this case).

OPT C0NTO indicates an optical 0 system control unit, which sends out branched light from the 1 system loop sending side from the 0 system side according to a loopback instruction, detects optical abnormalities, and notifies the outside. The optical 1 system control unit OPT C0NT 1 also has a similar function. HOLD recognition control unit TDSCONTO, TDSC
The ONTl recognizes the HOLD signal sent from the central station cs and controls instructions using the HOLD signal to other systems. Loopback control unit LPBCTLO, LP
BCTLI recognizes the optical abnormality notified from the optical 0 system control unit 0PTCONTO and the optical 1 system control unit 0PTCONT1, and instructs the control units 0PTCONTO and 0PTCONT1 to loop back, and also
Even if the optical abnormality disappears, the loopback instruction is maintained until the instruction by the HOLD signal disappears, as instructed by the OLD signal. By controlling like this.

The loopback configuration is maintained in a stable state until the faulty terminal station (optical down terminal station of both systems) is completely restored and becomes normal, thereby preventing the influence on other terminal stations.

〔Effect of the invention〕

As explained above, the present invention provides H
By sending out the OLD signal from the central office device, there is an effect of preventing an abnormal operation of a faulty terminal station (for example, continuous repetition of down and recovery) from affecting other terminal stations.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an optical loop communication network to which the present invention is applied;
Figure 2 is a configuration diagram showing the connection at the time of failure, Figure 6 (a)
, (b) are the conventional loopback configuration and 2, respectively.
Figure 4 for comparison with the loopback configuration of the present invention.
The figure shows an example of the configuration of a terminal station. In the figure, C8 is the central station equipment, sys is the system control unit,
TDSl, TDS2. TDS3tll, C3C
TLOC8CTL1 is the central control unit. Agent (7127) Patent attorney Yosuke Goto Central office equipment yIl+) Figure 1 Figure 2 (Q) (b) Figure 3

Claims (1)

[Claims] 1. A central office device that monitors and controls the entire optical communication network and a plurality of terminal devices that monitor and control the accommodated terminal lines are distributed, and these central office devices and terminal devices are divided into two systems, 0 system and 1 system, respectively.
In loopback control for system reconfiguration when both systems at a certain terminal station go down in a double loop transmission line with a duplex configuration, when both systems at a certain terminal station go down, the 0 system and 1 system loops are in opposite directions. When the terminal station is down, the terminal stations on both sides of the terminal station detect that the light is not being received and
When a reception error occurs in the system (or 0 system) loop, the transmission side of the 1 system (or 0 system) loop has a loopback means that branches the light transmission side of the 0 system (or 1 system) loop and sends it out. In the central station equipment, when the optical system of both systems goes down at a certain terminal station, a system control unit that monitors and controls both loops performs loopback reconfiguration control of the entire optical transmission line configured as a single loop using a terminal station loopback function. The system control unit sends a configuration holding signal to all terminal devices using a specific control channel, and the terminal device that receives this signal controls the other system to detect an optical reception abnormality due to the loopback configuration factor. 1. A loopback control method, comprising means for maintaining the loopback configuration without canceling it even if the configuration is restored, and returning the configuration to the normal configuration by deleting the configuration retention signal.