JPH04345219A - Optical repeater station and optical terminal station - Google Patents

Abstract

PURPOSE:To stop the output of an optical signal at a transmission side automatically at the interrupting of an input optical signal due to the fault of a transmission line. CONSTITUTION:The optical optical repeater 12 of an optical repeater 4 of the optical duplex transmission system monitors an input optical signal from a transmission line 6 and outputs monitoring information 103 such as input optical signal interruption. An optical repeater 103 repeater 13 inserts the monitoring information 103 to an output optical signal outputted to the transmission line 9 and transfers the result. The optical repeater 12 detects the monitoring information from the input optical signal when the input optical signal is not interrupted. When the monitoring information information detected by the optical repeater 12 is a signal representing the interruption of the input optical signal, the optical repeater 13 uses the monitoring information 103 to stop the transmission of the output optical signal. The operation is implemented similarly even in other optical repeater station 3 and optical terminal stations 1, 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical repeater station and an optical terminal station in an optical fiber transmission system, and more particularly to an optical repeater station and an optical terminal station having a function of transferring a transmission line monitoring signal.

0002

[Background Art] In conventional optical fiber transmission systems, when a failure occurs in a transmission line using optical fibers, if the receiving side of the failed relay section is an intermediate optical repeater, the optical signal input is cut off and the optical signal is The transmission of the data will also be stopped. Furthermore, when the receiving side of the faulty relay section is an optical terminal station, the optical signal input is interrupted. On the other hand, on the transmission side of the failed relay section, the upstream intermediate optical repeater including the optical terminal station operates normally and continues to send out optical signals.

A conventional example will be explained below using the block diagram of FIG. In this optical fiber transmission system, between the optical terminal station 21 and the optical terminal station 22, the optical relay station 2
Transmission lines 25 to 25 at optical repeaters 201 and 202 in 3 and 24
It is relayed and transmitted via 27. From the optical terminal station 22 to the optical terminal station 21 (hereinafter this transmission direction is referred to as downlink), the optical repeaters 203 and 204 in the optical relay stations 24 and 23 perform relay transmission via the transmission lines 28 to 30. are doing. Optical repeater 201
and 204, 202, and 203 are uplink and downlink pairs, respectively, and are accommodated in the same optical relay stations 23 and 24, respectively, and constitute one system. In this configuration, for example, the upstream transmission line 26
If a failure occurs in the optical repeater 202, the input of the optical signal is cut off, and the output optical signal to the transmission line 27 is also cut off. However, even in this case, the transmitting optical repeater 2 in the faulty relay section
At 01, the optical signal continues to be transmitted normally.

0004

[Problem to be solved by the invention] In these optical relay stations and optical terminal stations, the transmission side of the faulty relay section continues to send optical signals even during the fault, so fault recovery workers may mistakenly identify the transmission path. There was a risk of eye damage when looking into the end face of the optical fiber. Furthermore, during restoration work, the level of the optical signal input to the optical repeater on the receiving side becomes unstable, so the state of the transmission path also becomes unstable. To prevent this, it is conceivable to turn off the device power so as to cut off the output optical signal of the optical repeater on the transmitting side, but with high-density packaging, power is supplied to multiple systems from one power supply source. Due to the current state of affairs, turning off the power often also turns off the power of other systems unrelated to the failure, making this method virtually impossible.

[0005]

[Means for Solving the Problems] In the alarm transfer system of the present invention, when a fault occurs in the uplink transmission line, the link between the uplink optical repeater and the downlink optical repeater is transmitted to the faulty relay section. By transferring failure detection information to the transmitting optical repeater or, in some cases, to the optical terminal station, the transmission of optical signals by the transmitting optical repeater is stopped. Conversely, if a failure occurs on the downlink transmission path, failure detection is sent from the downlink optical repeater to the transmitting optical repeater in the faulty relay section or, in some cases, to the optical terminal station, via the uplink optical repeater. It has means for stopping the transmission of optical signals by the transmission-side optical repeater by transferring information.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram of one embodiment of the present invention.

[0007] The optical transmission system shown in FIG. 1 transmits data between an optical terminal station 1 and an optical terminal station 2 in the direction from the optical terminal station 1 to the optical terminal station 2 (hereinafter, this transmission direction is referred to as upstream). , transmission line 5, optical relay station 3
optical repeater 11, transmission line 6, optical repeater 12 of optical repeater station 4
, relay transmission is carried out through the transmission line 7. On the other hand, optical terminal station 2
In the direction from the optical terminal station 1 (hereinafter, this transmission direction is referred to as downlink), there are the transmission line 8, the optical repeater 13 of the optical repeater station 4, the transmission line 9, the optical repeater 14 of the optical repeater station 3, and the transmission line 8. Relay transmission is carried out through route 10. Optical fibers are used for the transmission lines 5-10. The optical terminal station 1 includes a transmitter 15 that sends out an optical signal to the transmission line 5 and a receiver 16 that receives the optical signal from the transmission line 10. Similarly, the optical terminal station 2 includes a transmitter 18 that sends out optical signals to the transmission line 8 and a receiver 17 that receives optical signals from the transmission line 7. Optical repeaters 11 and 14 included in optical repeater station 3 and optical repeaters 12 and 13 included in optical repeater station 4 form uplink and downlink pairs, respectively.
One system of intermediate optical relay stations is configured.

The monitoring information 101 is monitoring information indicating whether the input optical signal at the optical repeater 11 is normal or abnormal such as disconnection, or monitoring information about the transmitter 15 of the optical terminal station 1, the transmission line 5, and the optical repeater 11.
The monitoring information of the optical input signal at the receiving section 16 of the optical repeater 1 is the monitoring information transferred to the optical repeater 14 via the optical repeater 1 . The monitoring information to be transferred is inserted into surplus bits of the optical communication signal on the transmission path 5. The monitoring information 102 is monitoring information of the input optical signal at the optical repeater 14, or from the optical repeater 13 via the transmission path 9 and the optical repeater 14,
The monitoring information of the input optical signal of the optical repeater 12 is the monitoring information transferred to the optical repeater 11. Similarly, the monitoring information 103 is monitoring information of an input optical signal at the optical repeater 12, or monitoring information of an input optical signal at the optical repeater 14 via the optical repeater 11, the transmission line 6, and the optical repeater 12. The information is monitoring information transferred to the optical repeater 13. The monitoring information 104 is monitoring information of the input optical signal at the optical repeater 13, or monitoring information of the input optical signal of the optical terminal station 2 from the optical terminal station 2 via the transmission path 8 and the optical repeater 13. This is monitoring information transferred to the device 12. The monitoring information 105 is the monitoring information of the input optical signal of the optical terminal station 1 or the monitoring information of the input optical signal of the optical repeater 11 via the optical repeater 14, the transmission line 10, and the receiving section 16 of the optical repeater 1. This is the monitoring information to which the information is transferred. The monitoring information 106 is the monitoring information of the input optical signal of the optical terminal station 2, or the monitoring information of the optical repeater 12, the transmission line 7, and the receiving section 17 of the optical terminal station 2.
The monitoring information of the input optical signal of the optical repeater 13 is the monitoring information transferred. That is, each optical terminal station 1, 2 and optical repeater 11 to 14 inserts the state of the optical signal in the opposite direction into, for example, surplus bits of the communication signal and transfers it to the downstream optical repeater or optical terminal station. At the same time, the monitoring information transferred from the optical repeater or optical terminal station upstream of the received optical signal is read out. The read monitoring information is then transferred to a transmitter in the case of an optical repeater or optical terminal station in the opposite direction within the same system. Each of the optical repeaters 11 to 14 or the optical terminal stations 1 and 2 stops outputting the optical signal when monitoring information indicating the input optical signal is transferred from the destination via the above route.

[0009] If an optical signal interruption failure occurs in the transmission line 6 between the uplink optical repeater 11 and the optical repeater 12, the input optical signal will be interrupted at the optical repeater 12, and the input optical signal will be interrupted. This monitoring information is transferred from the optical repeater 13 to the optical repeater 12 and then to the optical repeater 11. Optical repeater 1
1, upon receiving this monitoring signal 102, the transmission optical signal to the transmission line 6 is stopped. There is no failure in the transmission line 6, and the optical repeater 1
When the input optical signal is normally input to the optical repeater 2, the optical repeater 12 detects the monitoring information 102 that is emitted from the optical repeater 14 and transmitted via the optical repeater 11 and the transmission line 6. When the optical repeater 12 detects a signal in the monitoring information 102 indicating that the input optical signal to the optical repeater 14 is disconnected due to an abnormality in the transmission line 9, the optical repeater 12 detects this signal in the monitoring information 102.
Transfer by 3. As a result, the optical repeater 13 stops sending out the output optical signal.

0010

As explained above, in the present invention, optical terminal stations and optical repeaters transmit information about the state of an input optical signal to an optical signal by using surplus bits of an optical communication signal on a transmission path in the opposite direction. The transmitting side of the optical terminal station and optical repeater is configured to stop the optical signal being transmitted when the destination transmits information that the input optical signal is disconnected. This has the effect that when the input optical signal is cut off, the optical signal output on the transmitting side can be automatically stopped.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment according to the invention.

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

[Explanation of symbols]

1, 2, 21, 22 Optical terminal station 3, 4, 23, 24 Optical relay station 5-10, 25-30 Transmission line 11-14, 201-204 Optical repeater 15, 1
8 Transmitting units 16, 17 Receiving units 101 to 106 Monitoring information

Claims (2)

[Claims] Claim 1: In an optical relay station using two-way optical fiber transmission system that uses two transmission lines with different transmission directions, the first transmission line is connected in the first transmission direction to the second transmission line. a first optical repeater that relays an optical signal; and a first optical repeater that relays an optical signal from a third transmission path in a second transmission direction opposite to the first transmission direction to a fourth transmission path. 2 optical repeaters, the first optical repeater has monitoring information output means for monitoring the input optical signal from the first transmission line and outputting monitoring information, and a monitoring information output means for monitoring the input optical signal from the first transmission line and outputting monitoring information, and a supervisory signal detection means for detecting a first supervisory signal from the input optical signal when the input optical signal is not detected, and the second optical repeater transmits the supervisory information to the output light output from the fourth transmission path. a transfer means for inserting the signal into the signal and transmitting it as a second monitoring signal; and an output optical signal stopping means for stopping the transmission of the output optical signal when the first monitoring signal is a signal indicating disconnection of the input optical signal. An optical relay station characterized by having: 2. In an optical terminal station of a bidirectional optical fiber transmission system using two transmission lines with different transmission directions, a receiver receiving an input optical signal from a first transmission line in a first transmission direction. and a transmitting unit that transmits an output optical signal from a second transmission path in a second transmission direction that is opposite to the first transmission direction, and the receiving unit transmits the input optical signal. monitoring information output means for monitoring signals and outputting monitoring information;
supervisory signal detection means for detecting a first supervisory signal from the input optical signal when the input optical signal is not disconnected; An optical terminal station comprising: means for transmitting a supervisory signal; and means for stopping transmission of the optical signal when the first supervisory signal is a signal indicating disconnection of the input optical signal.