JPH1022961A - 1-to-n optical line switch system using adm device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a 1-to-N optical line switch system using ADM devices having minimum system constitution without a control line between an optical switch and respective ADMs(add drop multiplexer) devices and without an optical switch. SOLUTION: In the 1-to-N optical line switch system using the ADM devices 101 to 104 and using one spare line 205 between opposed stations to prevent the disconnection of service against a fault caused in either one of plural active lines 201 to 204, the spare lines 301 of the plural ADM devices 101 to 104 generally called add drop multiplexes being communication equipments provided with an active/spare instantly switching function and executing slowly branching multiplexed repeating are connected in a spitting state in a station.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical line switch system, and more particularly to a 1: N optical line switch system using an ADM apparatus.

[0002]

2. Description of the Related Art A conventional one-to-N optical line switch system uses one backup line between opposing stations to protect against traffic service interruption due to a failure occurring in one of N working lines. Used for

FIG. 4 is a block diagram showing an example of a conventional one-to-N optical line switch system. Optical line terminal devices (hereinafter referred to as TERM devices) 111 to 114 for terminating the optical lines terminate the working lines 201 to 204, respectively, and the TERM device 115 for the backup line 2
05 is terminated. The spare lines 311 to 315 of each TERM device are connected to the optical switch 401, and the optical switch 401 selects one from N lines. In addition, each T
The ERM device and the optical switch 401 are connected to control lines 501 to 50.
5 is connected. Further, each TERM device has a function of branching and outputting the traffic from the low speed side to each of the working line and the protection line, and selecting one of the traffic from the working line and the protection line and outputting the traffic to the low speed side.

FIG. 5 is a block diagram showing an example of use of a conventional 1: N optical line switch system in a network.

Next, the operation will be described. First, an outline of how the 1: N line switching is performed in the network will be described. For example, when the active line 202 becomes an obstacle, the switching is performed according to the following procedure.

1) A request is made to the opposite station to branch the working line 202 to the protection line 205, and the opposite station branches.

2) When the own station is notified of the completion of the branch of the opposite station, it selects a backup line. At the same time, the current line 202 on the own station side is branched, and this is notified to the opposite station.

3) The opposite station selects the backup line 205. These three operations will be described with reference to FIG.

First operation. The TERM device 112 that has detected the failure of the working line 202 outputs a selection request to the optical switch 401 through the control line 502. Optical switch 40
1 outputs a request to switch the working line 202 to the TERM device 115 via the control line 505 based on the request. The TERM device 115 requests the one-to-N line protection system of the opposite station to branch the working line 202 at the opposite station to the protection line via the protection line 205. In the opposite station, when the TERM device 115 receives the branch request for the working line 202 through the protection line 205, it notifies the optical switch 402. The optical switch 402 selects 322 from the TERM device 122 and outputs it to 325. TE
In the RM device 125, the spare line 325 is connected to the spare line 20.
5 is output. Then, the completion of the branch of the working line 202 is notified to the own station through the backup line 205.

Second operation. The TERM device 115 that has received the completion of the branch at the opposite station notifies the optical switch 401 of the fact through the control line 505 and outputs the signal of the backup line 205 to the backup line 315. The optical switch 401 converts the signal of the backup line 315 into the backup line 312.
To the TERM device 112 to select the signal of the backup line 312 via the backup line 205 and output the signal to the low-speed side. In the TERM device 112, the spare line 3
Twelve signals are output to the low-speed side. Optical switch 401
Outputs the signal from the backup line 312 to the backup line 315, and outputs the signal to the backup line 205 by the TERM device 115. In the TERM device 115, the spare line 315
And outputs it to the backup line 205. At the same time, the own station notifies the opposite station that the branch of the working line 202 has been completed.

Third operation. The opposite station receiving the completion of the branch of the working line 202 in its own station outputs the traffic of the backup line 205 to the low-speed side of the TERM device 122 by the same operation as described in the second operation.

[0012]

Since the conventional one-to-N optical line switch system uses a TERM device, there are only two optical lines for each TERM device: a working line and a spare line. Is used for exchanging signals with the optical switch, which requires N eleven TERM devices, and also requires an optical switch to switch between the active and standby units.

Furthermore, since the optical switch is composed of passive elements, it exchanges optical signals with each TERM device. However, since this cannot be used as a control signal transmitting means, the optical switch and each TERM device can be used. There is a problem that a control signal is required between the devices and that the hardware of the conventional TERM device needs to be changed.

An object of the present invention is to use an ADM apparatus which does not require an optical switch and has a minimum system configuration.
An N-to-N optical line switch system is provided.

Another object of the present invention is to provide an optical switch and each AD.
An object of the present invention is to provide a highly reliable 1: N optical line switch system that does not require a control line between M devices.

[0016]

SUMMARY OF THE INVENTION A 1-to-N optical line switch system using an ADM apparatus according to the present invention has a 1
Communication device for low-speed branch multiplex relay having a function of immediately switching between active and standby systems in a 1-to-N optical line switch system for preventing service interruption for a failure occurring in any of a plurality of active lines using the standby line ADMs commonly called add-drop multiplexers
The backup line of the apparatus is connected in a skewered manner in the office.

Also, a 1-to-N ratio using the ADM apparatus of the present invention is described.
The optical line switch system uses a single protection line between a plurality of opposing stations to prevent a service interruption against a failure occurring in any of a plurality of working lines. The N optical line switch system is characterized in that backup lines of the plurality of ADM devices are connected in a skewered manner in each station between the opposing stations.

[0018]

Next, a first embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of a 1: N optical line switch system according to the present invention. FIG. 2 is a block diagram showing a configuration of the ADM apparatus in FIG. FIG. 3 is a block diagram showing a system configuration for explaining the operation of the 1: N optical line switch system of the present invention.

The ADM device 101 to the ADM device 104
Has a standby line access function having an active standby immediate switching function. With this function, each AD
The M-device separates the traffic of the backup line from the high-speed side (line) or low-speed side (tributary) independently of the working line.
Time-division switch. That is, as shown in FIG. 2, it is possible to input and output a transparent signal between the backup line 603 and the backup line 604 while the traffic of the working line is being input and output on the low-speed side.

As shown in FIG. 3, each of the ADM devices 101 to 104 terminates the working lines 201 to 204 and outputs the same to the low-speed side. A spare line 30 for each ADM device
As shown in the figure, 1 is connected in a skewered manner to each ADM device of the own station. The ADM device 104 further includes a backup line 20
5 to the counter office. Communication between each of the ADM devices 101 to 103 and the ADM device 104 is made by the Kl and K2 bytes of the SDH signal on the skewered backup line 301. Also, each of the ADM devices 101 to 104
Holds the number of the working line of the own station that is terminated as information.

Next, the operation when a failure occurs in the working line 202 of FIG. 3 will be described. As described in the related art, the 1: N optical line switch is executed by the following three operations.

1) A request is made to the opposite station to branch the working line 202 to the protection line 205, and the branch is made at the opposite station.

2) When the own station is notified of the completion of the branch of the opposite station, it selects a backup line. At the same time, the current line 202 on the own station side is branched, and this is notified to the opposite station.

3) The opposite station selects the backup line 205.

First operation. The ADM device 102 detects a failure in the working line 202 and notifies the skewer-like backup line 3 that the working line terminating at the own device has a failure.
01 and the ADM device 104
Notify. The Kl and K2 bytes are transparently transmitted to the ADM device 103 from the middle of the ADM device 102 on the way. Further, in the ADM device 104, the Kl and K2 bytes are transparently transmitted on the spare line 205. Kl,
Since the K2 byte contains information on what line is in what kind of fault state, there is no problem if it is transmitted transparently. The ADM device 104 of the opposite station transparently transmits the received Kl and K2 bytes to the spare line on the skewers. The ADM device 103 from the middle of the ADM device 102 in the middle does not cause a failure in the terminal line of the ADM device 102, and thus transmits the K1 and K2 bytes transparently as it is. In this way, the ADM device 102 of the opposite station knows the failure state of the signal output from the own device. Then, the ADM device 102 of the opposite station uses the time division switch function to branch and output the low-speed side traffic to a skewered backup line. Also,
At the same time, the branch is notified to the local station side by the Kl and K2 bytes. From the ADM device 103 of the opposing station to the AD of the opposing station
In the M device 104, the signal and the Kl and K2 bytes are transmitted transparently on the skewered spare line, and the branch state is notified to the own station side.

Second operation. Working line 202 from the opposite station
Is notified, the ADM apparatus 103 transmits the signal from the spare line 205 and the Kl and K2 bytes in a skewered manner to the spare line 3 from the ADM apparatus 104 of the own station.
01 is transmitted. Then, the ADM device 102 outputs a signal from the skewered backup line 301 to its own low connection side. At the same time, the traffic on the low-speed side of the device is skewered using the time-division switch function.
01, and the Kl and K2 bytes are used to notify the opposite station through the skewered spare line 301. The signal from the ADM device 102 and the Kl and K2 bytes are stored in the ADM devices 103 to 104 of the own station and A
The ADM device 103 is transmitted transparently from the DM device 104.

Third operation. The ADM device 102 of the opposite station outputs a signal from the skewered backup line 301 to the low-speed side of the own device based on the received Kl and K2 bytes.

It is to be noted that a 1-to-N ratio using the ADM apparatus of the present invention
The optical line switch system uses one backup line between each of the opposing stations to prevent service interruption for a failure occurring in any of the plurality of working lines. It goes without saying that if the 1: N optical line switch system of the present invention is provided, it can be applied to an optical network having a plurality of opposing stations.

[0030]

According to the present invention, a 1-to-N optical line switch system using an ADM apparatus which does not require an optical switch and has a minimum system configuration can be realized.
Reliable 1: N without the need for control lines between DM devices
There is an effect that an optical line switch system can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a 1: N optical line switch system according to the present invention.

FIG. 2 is a block diagram showing a configuration of each ADM device in FIG.

FIG. 3 is a block diagram showing a system configuration for explaining the operation of the 1: N optical line switch system of the present invention.

FIG. 4 is a block diagram showing an example of a conventional 1: N optical line switch system.

FIG. 5 is a block diagram showing an example of use of a conventional 1: N optical line switch system in a network.

[Explanation of symbols]

101-104 ADM device 111-115, 121-125 TERM device 201-204 Working line in 1-to-N switch system 205 Spare line in 1-to-N switch system 301 Spare line 311 to connect each ADM device in a skewered manner 315, 321 to 325 A spare line for connecting each TERM device and an optical switch in a star shape 401, 402 Optical switch 501 to 505 A control line for connecting each TERM device and an optical switch in a star shape 601 to 602 Working line of ADM device 603 604 ADM equipment backup line 605-606 ADM equipment low-speed interface

Claims (2)

[Claims] 1. A 1-to-N optical line switch system for preventing a service interruption from occurring in any one of a plurality of working lines by using one protection line between opposing stations. One-to-N optical communication system using an ADM device, characterized in that a plurality of ADM device backup lines commonly referred to as add-drop multiplexers are connected in a station in a skewered manner. Line switch system. 2. A method of using a single protection line between a plurality of opposing stations to prevent a service interruption from occurring in any of a plurality of working lines.
The 1-to-N optical line using an ADM apparatus according to claim 1, wherein in the optical-to-N optical line switch system, backup lines of the plurality of ADM apparatuses are connected in a skewered manner in the office for each of the opposing stations. Switch system.