JPH10303816A - Monitoring control system for wavelength multiplex communication network - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the reception of a monitoring control signal for a repeater and also to monitor an optional repeater via an end office without affecting a main signal by receiving the monitoring control signal that is sent to an optical repeater from a 1st end office at a 2nd end office via its optical multiplexer/demultiplexer and then transferring the received monitoring control signal to a 3rd end office via the optical multiplexer/demultiplexer. SOLUTION: A pair of incoming and outgoing optical fibers OPC1 and OPC2 are connected to four end offices A to D via the optical multiplexing/ demultiplexing devices 1 and 2. When the signal light of wavelength W2 , for example, is modulated by a monitoring control signal and transmitted from the office A, the control signal can be transmitted to only the repeaters (not shown in the figure) that are placed between the offices A and C. However, the repeater placed between the offices C and D can also receive the monitoring control signal when the control signal is transferred to the office D from the office C. The signal light which is modulated by the monitoring control signal can use a main signal and also an exclusive monitoring control signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to wavelength division multiplexing (WD).
M) A monitoring control system for monitoring an optical amplification repeater in an optical communication network to which the technology is applied.

[0002]

2. Description of the Related Art In recent years, research and development of optical communication networks to which wavelength division multiplexing (WDM) technology has been applied have been activated. In such an optical communication network, large-capacity transmission is enabled by wavelength-multiplexed optical signals.

[0003] On the other hand, failures in optical amplification repeaters are serious for optical communication networks. Therefore, in an optical transmission system using an optical amplification repeater, means for monitoring the state of the optical amplification repeater is required.

Here, the state of the optical amplifier repeater to be monitored is a bias current of an optical input / output power, a temperature of the pump power pump laser diode (LD), and a bias current of the pump LD.

In a conventional optical transmission system, FIG.
9, one terminal A or at least one optical multiplexer / demultiplexer, a plurality of terminals connected to the at least one optical multiplexer / demultiplexer through an optical transmission line, and a plurality of terminals placed on the optical transmission line. A second terminal station receives, via the optical multiplexer / demultiplexer, a supervisory control signal for the optical repeater sent from a first terminal station of the plurality of terminal stations, and At least one optical multiplexer / demultiplexer configured to transfer the monitored control signal to the third terminal through the optical multiplexer / demultiplexer, and an optical transmission line connected to the at least one optical multiplexer / demultiplexer. A plurality of terminal stations connected through the optical transmission line, having a plurality of optical repeaters placed on the optical transmission line, a supervisory control signal for the optical repeater sent from a first terminal station of the plurality of terminal stations, A second terminal receives through the optical multiplexer / demultiplexer, and transmits the received supervisory control signal to the optical multiplexer / demultiplexer. If the terminal B is configured to be transferred to a third terminal through a filter, the other terminal B is connected point-to-point through a plurality of optical repeater amplifiers REP1 to REP4. POINT) type transmission line configuration has been adopted.

In the supervisory control system in such an optical transmission system, a supervisory control signal (command signal for the optical amplifier repeater) is transmitted from the terminal station A to the optical amplifier repeater REP1. Optical amplification repeater REP1 that has received the monitoring control signal
Performs control corresponding to the received supervisory control signal, directs a response signal containing the status information of the optical amplifier repeater to the terminal station B together with the supervisory control signal, and transmits the response signal to the adjacent optical amplifier repeater R.
Send to EP2. In this way, the monitoring control signals are sequentially sent.

Here, as a method for transmitting the monitoring control signal and the response signal to the optical amplification repeater, a data signal to be transmitted is transmitted.
There is a wavelength multiplexing method in which a supervisory control signal (a command signal for controlling an optical amplification repeater) is superimposed on (main signal) a supervisory control signal having a wavelength different from that of the main signal.

FIG. 21 is a diagram for explaining an operation example of the optical amplification repeater in the superposition method. As shown in FIG. 21A, for example, a main signal M of 2.5 to 20 Gb / s is modulated with a monitoring control signal SV of 1 to several tens of MHz to generate a superimposed signal, which is sent to the optical fiber transmission line OP. .

In the optical amplifying repeater, as shown in FIG. 21B, an optical signal obtained by intensity-modulating the main signal M by the monitoring control signal SV is branched by the branching means BR. The branched optical signal is converted into an electric signal by a light receiving element PD such as a photodiode.

From the electric signal converted by the light receiving element PD, only the monitoring control signal SV is extracted by the filter FIL and guided to the control circuit CONT. Control circuit CONT
Controls the optical amplifying repeater based on the extracted monitoring control signal SV, and outputs a response signal SV ′ of a predetermined frequency corresponding to the state of the optical amplifying repeater. The pump laser diode LD is driven by the response signal SV '.

Here, the gain of the optical fiber amplifier AMP is proportional to the pump power. Therefore, the response signal S
The pump power proportional to V 'is pump laser diode LD
And the optical signal input to the optical fiber amplifier AMP is intensity-modulated in proportion to the response signal SV ′. Due to this operation, the response signal SV ′ is transmitted from the optical amplification repeater to FIG.
As shown in FIG. 1 (c), the signal can be superimposed on the input main signal M and the supervisory control signal SV and transmitted to the next optical amplification repeater.

FIG. 22 is a diagram for explaining an operation example of an optical amplifying repeater in a system in which a supervisory control signal SV having a wavelength different from that of the main signal M is wavelength-multiplexed. FIG. 22A shows an optical spectrum, which indicates that the supervisory control signal SV having a wavelength different from the wavelength of the main signal M is wavelength-multiplexed.

As shown in FIG. 22 (b), the wavelength-multiplexed optical signal is input, branched by the branching means BR, and the monitoring control signal SV is extracted by the filter FIL.
The extracted supervisory control signal SV is guided to the supervisory control signal receiving circuit SVREC, where it is photoelectrically converted and demodulated.

As in the example of FIG. 21, the optical amplifier repeater is controlled in accordance with the demodulated monitoring control signal SV, and a response signal SV 'having a predetermined frequency corresponding to the state is output. . The pump laser diode LD is driven by the response signal SV '.

The pump power proportional to the response signal SV 'is output from the pump laser diode LD, and the input optical signal of the optical fiber amplifier AMP is intensity-modulated in proportion to the response signal SV'. This operation makes it possible to send the response signal SV 'from the optical amplification repeater to the next optical amplification repeater together with the main signal M and the supervisory control signal SV.

FIG. 23 is a diagram showing an example of an optical transmission system (WDM network system) networked using the wavelength division multiplexing (WDM) technique. The transmission path uses at least one pair of optical fiber pair cables OPC for upstream and downstream communication lines, and a plurality of optical amplification repeaters REP are arranged to compensate for the loss.

Each of the plurality of optical amplifying repeaters REP includes two optical amplifiers FF and FR for up and down lines. Further, in the configuration shown in FIG. 23, an optical multiplexer / demultiplexer OSEP is arranged between the terminal stations A and D, and terminal stations B and C for dropping and inserting signals are connected to the optical multiplexer / demultiplexer OSEP. From each of the terminal stations A, B, C, and D, a plurality of signal lights having different wavelengths are wavelength-multiplexed,
The WDM signal is transmitted to one optical fiber.

The WDM signal is transmitted from, for example, the terminal station A, its output path is sorted for each wavelength by the optical multiplexer / demultiplexer OSEP, and is transmitted to the corresponding receiving terminal station B, C, or D. That is, in the system of FIG. 23, a different signal wavelength is assigned to each communication path.

FIG. 24 shows an example in which the network is formed in a ring shape. In this example as well, as in FIG. 23, at least one pair of optical fiber pair cables OPC is used on the transmission line for the upstream and downstream communication lines, and a plurality of optical amplification repeaters REP are arranged to compensate for the loss. . WDM
The output path of the signal is distributed for each wavelength by the optical multiplexing / demultiplexing apparatus OSEP, and is sent to the corresponding receiving terminal station.

The WDM networks shown in FIGS. 23 and 24 have the following features. A plurality of signal lights (WDM signals) having different wavelengths pass through one fiber. The main signal (WDM signal) is multiplexed / demultiplexed in the transmission path by the optical branching device OSEP. There are a plurality of terminal stations in one system, and a plurality of communication paths (optical paths) connecting them.

[0021]

However, first of all, FIG.
1. When the monitoring control signal transmission / reception method described with reference to FIG. 22 is applied to the system of FIGS. 23 and 24,
For example, the following problem occurs. A. Problems when the superposition method is applied to a WDM network: Even if a supervisory control signal is superimposed on a signal light of a certain wavelength, the signal light may not pass through all transmission paths. For this reason, it is impossible to send a supervisory control signal from one terminal station to all the relay amplifiers in the network.

For example, FIG. 25 shown corresponding to FIG.
In, among the upper and lower lines, shows only one line, it superimposes the monitor control signal from the terminal station A to the wavelength W _3, even when transmitted, passing path of the monitoring control signal terminal station A-
The monitor control signal can be transmitted only to the relay amplifier REP arranged between C.

Further, since the signal light power of a wavelength different from that of the signal light modulated by the monitor control signal is large, the ratio of the monitor control signal power to the total signal light power is reduced, and the received power is lower than that during single-wave transmission. . B. Problems in the case of using the wavelength division multiplexing method: A problem similar to the above A occurs when a communication path formed for main signal transmission is diverted as a communication path dedicated to a supervisory control signal. Further, when a communication path connecting the terminal station and all the repeaters is formed exclusively for monitoring and control, signal lights of a plurality of wavelengths are required only for monitoring and control.

For example, in the example shown in FIG. 26, only one side of the upper and lower lines is shown as in FIG. 25, but between the terminal A and the terminals AB, AC, and AD. All repeaters R
If the EP to send supervisory control signal, it is necessary to at least three band W ₁ to _W-3. On the other hand, there is a method of branching the signal light for monitoring and control as shown in FIG. 27, but it requires the same number of wavelengths as the number of terminal stations. Therefore, there is a problem that the transmission band cannot be used effectively.

Further, in order to improve the reception power of the supervisory control signal in the repeater, an optical filter may be used in the supervisory control signal receiving section of the repeater to extract only the signal light for the supervisory control signal. However, when a plurality of wavelengths are modulated by the supervisory control signal as described above, this method cannot be used.

Further, when the wavelength division multiplexing method is used, the same problem as the above A occurs. Accordingly, an object of the present invention is to provide a monitoring and controlling system for a wavelength division multiplexing communication network satisfying the following conditions.

First, the reception power of the supervisory control signal in the repeater is high. That is, it is easy for the repeater to receive the monitoring control signal, secondly, there is no influence on the main signal, thirdly, any repeater can be monitored from the terminal station,
Furthermore, a signal transmission band is used effectively.

[0028]

A first configuration of a monitoring and controlling system for a wavelength division multiplex communication network according to the present invention, which achieves the above object when employing a wavelength division multiplex communication network, comprises at least one optical multiplexer / demultiplexer, The at least one
A plurality of terminal stations connected to one optical multiplexer / demultiplexer through an optical transmission line, and a plurality of optical repeaters placed on the optical transmission line,
A second terminal station receives a supervisory control signal for the optical repeater sent from a first terminal station of the plurality of terminal stations through the optical multiplexer / demultiplexer, and divides the received supervisory control signal into the optical multiplexer / demultiplexer. And transmitting the data to the third terminal through a wave device.

According to a second aspect of the monitoring and control system for a wavelength division multiplexing communication network according to the present invention, in the first configuration, the first terminal station transmits the monitoring and control signal to a communication line allocated for main signal data. The second terminal station, which has transmitted to the second terminal station and received the supervisory control signal, modulates at least one wavelength of signal light by the supervisory control signal and uses the modulated at least one A signal light having a wavelength is multiplexed with another signal light and transferred to a third terminal station using a communication line allocated for the main signal data.

Further, a third configuration of the supervisory control system for the wavelength division multiplexing communication network according to the present invention, in the first configuration, wherein the first terminal station transmits the signal light of at least one wavelength by the supervisory control signal. Modulates the signal light having a plurality of wavelengths including the modulated signal light, wavelength-multiplexes the signal light, and sends the multiplexed signal light to the second terminal station. The second terminal station selects a wavelength from the received signal light and performs the monitoring. The third terminal station receives a control signal, modulates at least one wavelength of signal light with the received monitoring control signal, and wavelength-multiplexes a plurality of wavelengths of signal light including the modulated signal light. It is characterized by being transferred to

In a fourth configuration of the monitoring and control system for a wavelength division multiplexing communication network according to the present invention, in the first configuration, the first terminal station transmits signal light of at least one wavelength using the monitoring and control signal. The signal is modulated and sent to the second terminal station, and the second terminal station converts the wavelength of the received signal light into a different wavelength and transfers the converted signal light to the third terminal station.

Further, in a fifth configuration of the wavelength division multiplexing communication network monitoring and control system according to the present invention, in the third configuration, the second terminal station may include the monitor transmitted from the first terminal station. Reproducing the monitoring control signal by photoelectrically converting the signal light of at least one wavelength modulated by the control signal,
The reproduced supervisory control signal modulates a signal light having a wavelength different from the at least one wavelength.

Further, in a sixth configuration of the monitoring and control system for a wavelength division multiplexing communication network according to the present invention, in the third configuration, the second terminal station determines whether or not transfer is required based on the monitoring and control signal. When the transfer is unnecessary, the transfer of the monitor control signal is not performed.

According to a seventh aspect of the wavelength division multiplexing communication network supervisory control system according to the present invention, in the sixth aspect, the supervisory control signal is a signal transmitted from any terminal station to any optical repeater. The second terminal station reads the identification information of the monitor control signal, and if the corresponding optical repeater is present in the signal transmission direction, the second terminal station performs the monitor control The signal is transferred, and when the corresponding repeater does not exist, the monitor control signal is not transferred.

Still further, an eighth configuration of the monitoring and control system for the wavelength division multiplexing communication network according to the present invention, in the first or third configuration, wherein the plurality of monitoring control signals transmitted from the first terminal station are the plurality of monitoring control signals. Like passing through an optical repeater
A combination of optical paths is formed.

Further, a ninth configuration of the wavelength division multiplexing communication network supervisory control system according to the present invention comprises a first and a second terminal, a first optical transmission line connecting the first and the second terminal, At least one optical multiplexer / demultiplexer provided in the first optical transmission line;
And at least one third terminal connected to the at least one optical multiplexer / demultiplexer through a second optical transmission line, and an optical repeater disposed on the first and second optical transmission lines. And a wavelength division multiplexing communication network for performing optical wavelength division multiplexing communication between the first and second terminal stations and the at least one third terminal station, wherein the first terminal station is adjacent to the third terminal. Sending an optical signal on which the supervisory control signal for the optical repeater is superimposed to one of the stations; the third terminal sequentially transmitting the optical signal on which the supervisory control signal is superimposed to an adjacent terminal; Transferring an optical signal on which the monitor control signal is superimposed from the last terminal station of the third terminal station to the adjacent second terminal station;
Is characterized in that an optical path is formed so as to send an optical signal in which the supervisory control signal is superimposed on the first terminal station.

According to a tenth configuration of the wavelength division multiplexing communication network supervisory control system according to the present invention, in the ninth configuration, the network passes between the first and second terminal stations and at least one third terminal station. The optical signal on which the monitoring control signal is superimposed is an optical signal having the same wavelength.

Still further, an eleventh configuration of the wavelength division multiplexing communication network monitoring and control system according to the present invention comprises
A second terminal station, first upstream and downstream optical transmission lines connecting the first and second terminal stations, and at least one optical multiplexer / demultiplexer provided in the first upstream and downstream optical transmission lines , At least one third terminal connected to the at least one optical multiplexer / demultiplexer through second upstream and downstream optical transmission lines, respectively, and
And an optical repeater arranged on second upstream and downstream optical transmission lines, and further performs optical wavelength multiplex communication between the first and second terminal stations and the at least one third terminal station. In a wavelength division multiplexing communication network, each of the first and second terminals and the at least one third terminal is connected to an adjacent terminal through the at least one optical multiplexer / demultiplexer in a corresponding upstream and downstream direction. An optical signal in which a supervisory control signal for the optical repeater is superimposed is transmitted through a path passing through the optical transmission line.

In a twelfth configuration of the wavelength division multiplexing communication network monitoring and control system according to the present invention, in the eleventh configuration, the second terminal station and the at least one third terminal station are input. The optical wavelength of the supervisory control signal is output at a wavelength different from the input wavelength.

A thirteenth configuration of the wavelength division multiplexing communication network monitoring and control system according to the present invention comprises a first terminal station and an optical multiplexer / demultiplexer for optically demultiplexing an optical signal sent from the first terminal station. A second and a third terminal for receiving the optical signal branched by the optical multiplexer / demultiplexer; and a branch from the optical multiplexer / demultiplexer from the first terminal to the optical multiplexer / demultiplexer. First optical paths to be respectively reached to the second and third terminal stations;
Each of the second and third terminal stations leads to the optical multiplexer / demultiplexer, and is combined by the optical multiplexer / demultiplexer to form a second optical path to the first terminal. The signal light modulated by the supervisory control signal is passed through the first and second optical paths.

Further, a fourteenth configuration of the wavelength division multiplexing communication network monitoring and control system according to the present invention comprises a first and a second configuration.
And at least one first optical multiplexer / demultiplexer provided in an upstream and downstream optical transmission line connecting the first and second terminal stations, and the at least one first optical multiplexer / demultiplexer. A first path having at least one third terminal station connected to each of the devices through upstream and downstream optical transmission paths, a fourth and a fifth terminal station, and between the fourth and the fifth terminal stations. And at least one second optical multiplexer / demultiplexer provided in the upstream and downstream optical transmission lines, and at least one second optical multiplexer / demultiplexer connected to the at least one second optical multiplexer / demultiplexer through the upstream and downstream optical transmission lines, respectively. In an optical wavelength division multiplexing communication network having a second path having one sixth terminal station and performing optical wavelength division multiplexing communication on the first path and the second path, the first terminal station has: Sending an optical signal superimposed with a supervisory control signal to one of the adjacent third terminal stations,
The third terminal sequentially transfers an optical signal in which the supervisory control signal is superimposed to an adjacent terminal, and further transmits a signal from the last terminal of the third terminal to the adjacent second terminal. The second terminal station transmits an optical signal with the supervisory control signal superimposed thereon to the fourth terminal station, and the fourth terminal station is adjacent to the fourth terminal station. An optical signal on which a supervisory control signal is superimposed is sent to one of the sixth terminal stations, and the sixth terminal station sequentially transmits an optical signal on which the supervisory control signal is superimposed to an adjacent terminal station, ,
An optical path is formed such that an optical signal on which the monitor control signal is superimposed is transferred from the last terminal station of the sixth terminal station to the fifth terminal station adjacent thereto.

According to a fifteenth configuration of the supervisory control system for a wavelength division multiplexing communication network according to the present invention, in the fourteenth configuration, the wavelength of the light on which the supervisory control signal passing between the terminal stations is superimposed is the same wavelength. Light.

Further, a sixteenth configuration of the monitoring and controlling system for a wavelength division multiplexing communication network according to the present invention comprises a plurality of optical multiplexers / demultiplexers connected on a ring by an optical transmission line, and each of the plurality of optical multiplexers / demultiplexers. In a wavelength division multiplexing communication system having a plurality of terminal stations connected to a plurality of terminal stations and performing optical wavelength division multiplexing at the terminal stations, light on which a supervisory control signal is superimposed is transmitted through the plurality of optical multiplexer / demultiplexers to the adjacent plurality of An optical path is formed so as to pass between the terminal stations.

Further, a seventeenth configuration of the supervisory control system for the wavelength division multiplexing communication network according to the present invention is the sixteenth configuration, wherein the light on which the supervisory control signal is superimposed uses the same wavelength light at each terminal station. It is characterized by.

An eighteenth configuration of the wavelength division multiplexing communication network supervisory control system according to the present invention comprises a plurality of terminal stations connected to each of the plurality of optical multiplexers / demultiplexers, and the plurality of optical multiplexers / demultiplexers. In a wavelength division multiplexing communication system which is connected in a ring shape by an upstream optical transmission line and a downstream optical transmission line and performs optical wavelength division multiplexing communication between the respective terminal stations, an optical signal on which the supervisory control signal is superimposed is converted into an optical signal. The path between the adjacent terminal stations connected via a demultiplexer is connected to an upstream optical transmission path, and the path between the adjacent terminal stations connected via the optical multiplexer / demultiplexer is connected to a path connected via a downstream optical transmission path. Characteristic monitoring and control system for WDM networks.

In a nineteenth configuration of the wavelength division multiplexing communication network monitoring and control system according to the present invention, in the eighteenth configuration, the wavelength of the monitoring control signal flowing in the upstream optical transmission line and the wavelength of the monitoring control signal flowing in the downstream optical transmission line are different. The wavelength of light is different.

Further, a twentieth configuration of the wavelength division multiplexing communication network monitoring and control system according to the present invention comprises a plurality of optical multiplexer / demultiplexers, a plurality of terminal stations connected to each of the plurality of optical multiplexer / demultiplexers, In a wavelength division multiplexing communication system in which the plurality of optical multiplexer / demultiplexers are connected in a ring shape by an upstream optical transmission line and a downstream optical transmission line, and optical wavelength multiplex communication is performed between the terminal stations, two adjacent terminal stations are connected. And upstream and downstream optical paths, which are connected to each other, and the upstream and downstream paths are allocated to different fibers, and the optical main signal modulated by the supervisory control signal is passed through the optical path.

Further, the twenty-first configuration of the monitoring and control system for a wavelength division multiplexing communication network according to the present invention comprises a twentieth configuration.
Is characterized in that the signal wavelengths of the 2N optical paths selected for transmitting the supervisory control signal are the same.

Further, a twenty-second configuration of the wavelength division multiplexing communication network supervisory control system according to the present invention comprises
In any one of the configurations (1), the signal light for supervisory control is
It is characterized by being modulated with a data signal, and a supervisory control signal is superimposed on the data signal.

A twenty-third configuration of the wavelength division multiplexing communication network monitoring and control system according to the present invention comprises
In any one of the above configurations, the signal light for supervisory control is dedicated to the supervisory control signal.

Further, the monitoring and control system for a wavelength division multiplexing communication network according to the present invention is characterized in that the first and second embodiments are the same.
In any one of the constitutions (1), the monitor control signal receiving section of the repeater includes a filter that transmits only the signal light modulated by the monitor control signal.

Further, a twenty-fifth configuration of the wavelength division multiplexing communication network monitoring and control system according to the present invention is the first, second or third configuration in which the optical repeater is composed of a plurality of optical amplifiers, and each optical amplifier is One optical amplifier that has received a supervisory control signal has a function of transferring the supervisory control signal to another optical amplifier.

According to a twenty-sixth configuration of the wavelength division multiplexing communication network monitoring and control system according to the present invention, in the eleventh configuration, at least one optical multiplexer / demultiplexer and an optical transmission line are connected to the at least one optical multiplexer / demultiplexer. A plurality of terminal stations connected through the optical transmission line, having a plurality of optical repeaters placed on the optical transmission line, a supervisory control signal for the optical repeater sent from a first terminal station of the plurality of terminal stations, The second station is configured to receive through the optical multiplexer / demultiplexer, and to transfer the received supervisory control signal through the optical multiplexer / demultiplexer to a third terminal. The optical wavelength of the supervisory control signal passing between them is the same at all the terminal stations.

Further, a twenty-seventh configuration of the monitoring and control system for a wavelength division multiplexing communication network according to the present invention is the eighteenth configuration, wherein the optical wavelength of the monitoring control signal flowing through the upstream optical transmission line and the downstream optical transmission line The monitoring control signal flowing through the same uses the same optical wavelength.

A twenty-eighth configuration of the wavelength division multiplexing communication network supervisory control system according to the present invention is the system of any one of the first to twenty-seventh aspects, wherein the supervisory control signal is modulated by a supervisory control signal in accordance with the position of the repeater to be monitored. It is characterized in that the signal wavelength to be switched is switchable.

Further, in a twenty-ninth configuration of the wavelength division multiplexing communication network supervisory control system according to the present invention, in the twenty-eighth configuration, the supervisory control signal receiving unit of the repeater is configured such that only the signal light modulated by the supervisory control signal is transmitted. Characterized by having a filter that transmits light.

[0057]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or similar components will be described with the same reference numerals or reference symbols.

Before describing each embodiment,
For easy understanding of the present invention, a basic concept configuration of the present invention will be described.

FIG. 1 is a block diagram illustrating the transfer of a supervisory control signal as a first feature of the present invention. Here, the transfer of the supervisory control signal means that the supervisory control signal transmitted by a certain terminal station is once received by another terminal station, and the supervisory control signal is transferred from the other terminal station to the repeater. In FIG. 1, a pair of upstream and downstream optical fibers OPC1 and OPC2 are connected to four terminal stations A to D through optical multiplexing / demultiplexing devices 1 and 2, respectively.

For example, considering the case where the signal light of the wavelength W ₂ is modulated by the supervisory control signal and transmitted from the terminal station A, a repeater (not shown) disposed between the terminal stations A and C is considered. ) Can only send a supervisory control signal. However, if the supervisory control signal is transferred from the terminal station C to the terminal station D, the supervisory control signal, which is a command signal, is also sent to a repeater (not shown) disposed between the terminal stations C and D. Becomes possible.

The signal light to be modulated by the monitoring control signal may be a main signal or may be dedicated to the monitoring control signal. By providing a function of transferring a supervisory control signal to each terminal station, the supervisory control signal can be transmitted.

FIG. 2 is a diagram showing an example of a schematic configuration of a terminal station having the function of transferring the monitoring control signal. In this example,
Monitor control signal is superimposed on the main signal wavelength W _D. In the end station, to the wavelength separating a signal light having a wavelength W _D modulated by the supervisory control signal from a WDM signal by the demultiplexer 10. Light of other wavelengths is input to a main signal processing unit (not shown) of a corresponding wavelength, and a main signal modulated at each wavelength is extracted.

In the optical branching circuit 4, a main signal and a supervisory control signal are branched from the optical signal of the wavelength W _D , and the branched main signal is input to a main signal processing unit (not shown). The signal is input to the signal processing unit 5.

In the supervisory control signal processor 5, the optical signal is converted into an electric signal by the photoelectric converter 50, and the supervisory control signal reproducer 51 reproduces the supervisory control signal.

Thereafter, the supervisory control signal reproduced by the supervisory control signal reproducing section 51 is converted by the signal processing circuit 52 into a signal superimposed on the bias current of the laser 7 emitting at a predetermined wavelength of the transmission processing section 6. .

Therefore, the transmission processing section 6 uses the drive current in which the monitoring control signal is superimposed on the bias current to obtain the wavelength W.
_U drives a laser diode LD that emits light. Further, the emission output of the laser diode LD is controlled by an external modulator 3.
Is modulated by the main signal transmitted from the terminal station.

Next, the output of the external modulator 3 is
1 is input. The multiplexer 11 multiplexes the optical signal from the transmission processing unit of another wavelength and the input light from the external modulator 3 and outputs the multiplexed signal to the optical transmission line.

In the terminal having such a configuration, the signal processing circuit 52
It is also possible to transmit its own monitoring and control signal.

A second feature of the present invention is that the range in which the supervisory control signal reaches the optical repeater can be expanded. That is, the configuration is such that the monitoring control signal is sent to all the optical repeaters in the network.

Therefore, in the present invention, an optical path for a supervisory control signal is formed so that a supervisory control signal transmitted from an arbitrary terminal passes through the entire network, and this is combined with a terminal having a supervisory control signal transfer function. Thus, an optical transmission path is formed so that the monitoring control signal passes through all the optical repeaters.

As an example, as shown in FIG. 3, an optical path of the supervisory control signal in which a thick arrow line is formed is shown. A transmission path is selected so as to connect all the terminal stations, and an optical path is formed.

In FIG. 3, the optical path for the supervisory control signal may be a combination of optical paths passing through all the transmission paths from among the optical paths already formed for the main signal.
Also, it may be newly provided exclusively for monitoring control.

At this time, the optical paths of the supervisory control signal do not overlap as much as possible in one fiber, the distance of each optical path is as short as possible, the number of wavelengths used is as small as possible, It is necessary to consider conditions such as the same wavelength as much as possible.

Here, the wavelength band in which signal transmission is possible is mainly limited by the gain wavelength band of the optical amplifier. In order to make effective use of this transmission band, it is preferable that the number of wavelength multiplexes spent for monitoring and control be as small as possible. It is also desirable that the wavelengths used for monitoring and control be the same. For example,
When an optical filter is used in an optical repeater to receive a supervisory control signal, the transmission wavelength of the optical filter can be unified in all repeaters if the wavelength is the same.

It is easy to form an optical path for a supervisory control signal so as to satisfy such a condition, especially in a linear or ring type WDM network. For example, in the network of FIG. 3, a wavelength W _3, W _4, W ₂ and is used for monitoring the control signals, by assigning a wavelength as in Fig. 4 this, the wavelength for the supervisory control W ₄ one It is possible to unify the two.

When the supervisory control signal superimposition method described with reference to FIG. 21 is used, the optical path for the supervisory control signal is also used for the main signal. In the example of the network of FIGS. 3 and 4, the number of optical paths for the main signal is the same. That is, the change of the wavelength assignment does not limit the optical path of the main signal.

An embodiment for realizing the features of the present invention will be described below.

FIG. 5 is a conceptual diagram showing a first embodiment of the present invention. Terminal stations A to D are connected to the optical multiplexing / demultiplexing devices 1 and 2 through an optical repeater amplifier (not shown).
Now, when transmitting a supervisory control signal to the repeater in the terminal station B-D section, the supervisory control signal is transmitted from the terminal station A to the terminal station B. Next, the supervisory control signal is transferred from the terminal station B to the optical repeater amplifier to be monitored between the terminal stations BD.

Here, as a method of transmitting the monitoring control signal from the terminal station A to the terminal station B, a method using electric communication means is possible. For example, in a transmission system using an SDH code, a part of main signal data can be used as a monitoring communication line (order wire). Therefore, WD
In the M network, when a communication path for a main signal exists between two terminal stations, it is possible to transfer a supervisory control signal using an order wire.

FIG. 6 is an example block diagram of the embodiment of FIG. The signal light having the wavelength W ₂ among the wavelength multiplexed (WDM) signals is modulated by the monitoring control signal and transmitted from the terminal station A. The terminal station signal light having a wavelength W ₂ B, selected wavelength to receive a monitoring control signal. Terminal station B modulates the signal light having a wavelength W ₄ in the monitor control signal further received, and sends the multiplexed with other signal light.

As a result, it becomes possible to send a supervisory control signal from the terminal station A to a repeater (not shown) in the BD section. The signal light modulated by the monitoring control signal may use a main signal or may be dedicated to the monitoring control signal.

Therefore, in order to realize this method, a new optical transmitting / receiving terminal having a function of transferring a supervisory control signal to the repeater is required.

FIG. 7 is a block diagram of a configuration example for realizing the function of transferring the monitoring control signal in the optical transmitting / receiving terminal. It has a splitter 10, a multiplexer 11, and a wavelength converter 3. WDM of a plurality of wavelengths W _{1 to} W _n received from a transmission line
The signal splitter 10 separates the signal light of the wavelength (W _D ) modulated by the supervisory control signal from the signal. The signal light of another wavelength is sent to a processing unit of another wavelength as it is.

[0084] The signal light separated wavelength W _D is converted by the wavelength converter 30 to the signal light of the W _U. Then, the WDM signal from the processor of another wavelength is wavelength-multiplexed by the multiplexer 11 and transmitted to the transmission line. As the wavelength converter 30,
A circuit to which a semiconductor optical amplifier is applied can be used.

FIG. 8 is a block diagram showing an example of the configuration of the wavelength converter 3 of the optical transmitting / receiving terminal having the supervisory control signal transfer function of FIG. In this terminal station configuration, as described in FIG. 7, the wavelength W _D modulated from the WDM signal by the supervisory control signal is used.
Is separated by the splitter 10 in wavelength.

When the monitoring control signal is superimposed on the main signal, the signal light is branched by the optical branching circuit 4 to a main signal processing unit (not shown) and the monitoring control signal processing unit 5. If the signal light is dedicated to the monitoring control signal, the optical branch circuit 4 is not necessary.

In the monitoring control signal processor 5, the signal light is photoelectrically converted by the photoelectric converter 50. Next, the monitoring control signal converted into the electric signal is received and reproduced by the monitoring control signal receiver 51. Further, a current superimposed on the bias current of the laser diode is generated by the signal processing circuit 52 in accordance with the received and reproduced monitoring control signal.

Therefore, in the transmission processing section 6, the current corresponding to the monitoring control signal is superimposed on the bias current from the bias current source 70, and drives the laser diode LD which emits light of the wavelength Wu. As a result, the laser diode LD outputs light of the wavelength Wu whose intensity is modulated by the monitoring control signal. The emission output from the laser diode LD is further modulated by a main signal by the external modulator 3 and output from the transmission processing unit 6.

The output light of the external modulator 3 is multiplexed with a signal of another wavelength by the multiplexer 11 and transmitted to the transmission line.
Note that the signal processing circuit 52 can output the monitoring control signal sent from the repeater as it is, perform only wavelength conversion, and send it out to the transmission line.

FIG. 9 shows a modification of the configuration shown in FIG.
In Figure 8, it is branched received light having a wavelength W _D is the optical branch circuit 4, a configuration in which a supervisory control signal and the main signal are extracted in a separate circuit. On the other hand, the configuration in FIG. 9 is a configuration in which the main signal processing unit 9 extracts a main signal and a supervisory control signal. Therefore, the optical branch circuit 4 of FIG. 8 is not provided in FIG.

Further, the configuration of the main signal processing section 9 in FIG. 9 is basically the same as the configuration of the monitoring control signal processing section 5 in FIG. That is, in the monitoring control signal processing unit 5 in FIG. 8 and the main signal processing unit 9 in FIG. 9, the photoelectric converters 50 and 60 and the signal processing circuits 52 and 62 have the same functions, respectively.

Further, the monitor control signal receiver 51 shown in FIG.
Although only the function of receiving and reproducing the monitoring control signal from the electric signal converted by the photoelectric converter 50 is provided, the monitoring control signal extraction circuit 61 in FIG. 9 reproduces the main signal in addition to the function of receiving and reproducing the monitoring control signal. It has a function to output.

Also, in FIG. 9, the functional operation after the signal processing circuit 62 is the same as that in FIG. 8, and the description will not be repeated. In FIG. 9, an optical amplifier 8 is provided between the transmission processing unit 6 and the multiplexer 11. This is provided as necessary according to the level of the light emission output of the laser diode 7.

Here, the signal processing circuit 5 shown in FIGS.
2 and 62 can be configured using a CPU. As a function of the signal processing circuit, it is determined whether or not the transfer of the monitor control signal is necessary, and if not necessary, the transfer of the monitor control signal is not performed.

[0095] In the monitoring control signal, information for identifying which signal is transmitted from which terminal to which repeater is described. Therefore, if there is a repeater to be monitored in a direction in which the signal processing circuits 52 and 62 read the identification information and transmit the signal light, the monitoring control signal is transferred. If it does not exist, it is possible not to transfer.

Such a function is necessary to prevent the monitoring control signals input to the respective repeaters from overlapping.

FIG. 10 illustrates a WDM network.
Form a combination of optical paths that pass through all transmission paths,
FIG. 2 is a block diagram illustrating an example of a configuration for performing monitoring control of a WDM network that allows a signal light modulated with a monitoring control signal to pass through a formed optical path and enables a terminal to monitor a repeater in the network.

In FIG. 10, the wavelength of the optical signal is changed from the terminal station A to the terminal station C by the wavelength W ₃ , and from the terminal station C to the terminal station B by the wavelength W ₄ using the supervisory control configuration of FIG. the wavelength W ₂ from the terminal station B to the terminal station D, and set the optical path so as to further monitor the control signals by the wavelength W ₄ from the terminal station D to the terminal station a to pass through all the optical transmission path.

Therefore, for example, it becomes possible to send a supervisory control signal from the terminal station A to all the repeaters. Here, FIG.
The optical path for the supervisory control signal that enables the transmission of the supervisory control signal to all the repeaters as described above must satisfy the following conditions.

The optical paths for monitoring and control in one optical fiber should not overlap as much as possible. This is to prevent the same supervisory control signal from reaching the same repeater more than once.

The distance of each optical path is as short as possible. This is because the shorter the distance, the higher the SN of the supervisory control signal.
This is because R is good and reception is easy.

The number of wavelengths used is as small as possible. This is to effectively use the transmission band.
Furthermore, the wavelengths used should be as identical as possible. For example, when an optical filter is used in a repeater for receiving a monitoring control signal, if the wavelength is the same, the center wavelength of the optical filter can be unified in all repeaters.

It is relatively easy to form an optical path for a supervisory control signal so as to satisfy the above condition in the linear or ring type WDM network described with reference to FIGS.

Next, an embodiment for forming an optical path for such a supervisory control signal will be described.

FIG. 11 shows an example, and FIG.
This is a linear WDM network having four terminal stations including terminal stations A and B at both ends, which is configured using the optical multiplexing / demultiplexing apparatuses 1 and 2 described in (a). Three optical paths connecting two adjacent terminals and passing a signal from terminal A to terminal B, and one optical path connecting terminals A and B at both ends and passing a signal from B to A. One optical path is formed for transmitting a supervisory control signal.

That is, in FIG. 11, the terminal station A moves to the adjacent terminal station C, the terminal station C moves to the adjacent terminal station D, and the terminal station D moves to the terminal station B.
, And an optical path for a supervisory control signal is formed from the terminal station B to the terminal station A. Therefore, the signal light modulated by the supervisory control signal passes through a total of four formed optical paths.

Further, when the optical path is formed as described above, the optical wavelength of the monitor control signal is the same (W _{4 in} the example of FIG. 11).
It is possible to

FIG. 12 is different from the embodiment of FIG. 11 in that the optical path in the downstream direction, that is, from the terminal station B to the terminal station A is not direct but passes through the terminals D and C. At this time, in the example of FIG. 12 wavelengths W ₁ is used in the downlink.

When the optical path is formed as described above, the terminal station A
The signal light wavelengths of three optical paths through which signals pass from the terminal station B to the terminal station B are denoted by W _d (W _{4 in} FIG. 12). By setting the signal light wavelength of the path to W _U (W _{1 in} FIG. 12), it is possible to limit the signal wavelength for monitoring and control to two wavelengths.

Although the number of required wavelengths is increased by one as compared with the embodiment of FIG. 11, the distance of each optical path can be minimized.

Here, in the configuration shown in FIG. 12, the signal wavelength for monitoring and control is used as the upstream wavelength, and another wavelength is used for the downstream. However, the optical multiplexing / demultiplexing circuit having the configuration shown in FIG. If used, the transmission lines connected to the terminal stations C and D require two fiber transmission lines, but the wavelengths can be the same in the upstream and downstream directions.

FIG. 13 shows an embodiment obtained by further modifying FIG. In the optical path configuration of FIG. 12, it is necessary to use two wavelengths for the supervisory control signal. If the optical path through which the supervisory control signal passes is dedicated to the supervisory control signal, it is possible to send the supervisory control signal to all the optical repeaters using only one wavelength.

In this method, an optical path is formed as shown in FIG. The signal light having a wavelength W ₄ is a supervisory control from the terminal station. The signal light for monitoring and control transmitted from the terminal station A is
In the optical multiplexing / demultiplexing devices 1 and 2, power is branched and guided to two terminal stations B and C adjacent to each other. The signal light for monitoring and control transmitted from the two adjacent terminal stations B and C is power-coupled by the optical multiplexing / demultiplexing devices 1 and 2 and enters the terminal station A.
By adopting such an optical path in all the terminal stations, it becomes possible to send the supervisory control signal to all the repeaters with only one wavelength.

Here, the optical multiplexer / demultiplexer 1 in FIG.
FIG. 14 shows an example of a configuration for realizing the branching and coupling of the signal light for monitoring and control in 2. As shown, the optical demultiplexer 10
1 to 103, optical multiplexers 104 to 106, and optical coupler 10
7, 108.

The wavelength W ₁ transmitted by the optical fiber transmission line
WDM optical signal to _W-4 is separated into each wavelength signal in the optical demultiplexer 101. Among them, the optical signal of one wavelength, that is, the optical signal of wavelength W ₄ in FIG. 9 is branched in power by the optical coupler 107 and input to the adjacent optical multiplexer 106.

The WDM optical signal input to the optical demultiplexer 103 is separated into respective wavelength signals. An optical signal of one of the wavelengths is input to the optical coupler 108, is branched in power, and is input to the optical multiplexers 104 and 105. The configuration shown in FIG. 13 can be realized by using such an optical multiplexer / demultiplexer.

FIG. 15 is a diagram showing two adjacent WDM networks in a linear WDM network composed of a plurality of fiber pairs and having N terminals.
The upstream and downstream optical paths (2N-2 total) connecting the terminal stations are formed, the upstream and downstream lines are allocated to different fiber transmission lines, and the signal light modulated by the supervisory control signal passes through this optical path. This is an example.

FIG. 15 shows an example in which two optical fiber pairs OFP1 and OFP2 are used. The terminal station x-1 and the terminal station x-2 (x = A, B, C, D) are installed in the same station. Terminal station x-1 is for optical fiber pair OFP1, terminal station x-
2 is used as a terminal for the optical fiber pair OFP2.

Further, the optical fiber pair OFP1 and the optical fiber pair OFP2 exist in the same cable.

In this manner, in a linear WDM network having a number N of terminal stations composed of a plurality of fiber pair lines, an upstream optical path and a downstream optical path (total 2N−2) connecting two adjacent terminal stations are formed. Assign downstream lines to different fibers.

The signal light modulated by the monitor control signal passes through a total of N optical paths. In the embodiment of FIG. 13, it is necessary to use two wavelengths for the supervisory control signal. However, when two fiber pairs OFP1 and OFP2 can be used, an optical path can be formed as shown in FIG. 15 to make the signal light wavelengths for monitoring and control the same.

It is to be noted that it is possible to easily realize the present invention on a ring type network based on the above-described embodiments of the linear network shown in FIGS.

Further, by combining the embodiments described above, it is possible to send a supervisory control signal from any terminal station to any repeater in at least a linear or ring WDM network. 1 to 13 and FIG.
In FIG. 5, a bold line portion of each terminal station indicates a supervisory control signal to be transferred.

In the above embodiment, the optical paths for monitoring and control do not overlap as much as possible in one fiber.
The distance of each optical path is as short as possible. Use as few wavelengths as possible. Furthermore, the condition that the wavelengths used are as identical as possible is fulfilled.

Here, the signal light for monitoring and control may be modulated with a main signal (data signal) and superimposed thereon, or may be dedicated to the monitoring and control signal. When the optical path for the main signal has a full mesh configuration (a configuration with an optical path between all two terminal stations), the optical path can also be used for main signal transmission. It is more effective to use the superimposition method.

Further, in order to improve the receiving sensitivity of the supervisory control signal in the repeater, it is effective to equip the supervisory control signal receiving section of the repeater with an optical filter to remove unnecessary wavelength components. In this case, the signal light for monitoring and control is set to 1
By setting the wavelength, an optical filter can be used, and the center wavelength can be unified for all repeaters.

Here, returning to FIG.
To send a supervisory control signal to a repeater between terminal stations DB. In the terminal station A, and sends the modulated signal light having a wavelength W ₄ in the monitor control signal. End station C receives the signal light having a wavelength W _4, and sends modulates the supervisory control signal is again the signal light having a wavelength W _4. That is, the monitoring control signal is transferred.

The terminal D also transfers the supervisory control signal in the same manner as the terminal C. In this way, the monitoring control signal is transmitted to the terminal D
-Reach the repeater between B. However, in this state, the terminal station permanently transfers the supervisory control signal, and the same supervisory control signal reaches the repeater many times. Further, when the optical paths overlap as shown in FIG. 12, there is a problem that the monitoring control signal reaches the same repeater twice.

Thus, identification information is used as one method for solving this problem. That is, the signal light having a wavelength W ₄ after reaching the relay between the end stations D-B, to reach the terminal station B. Therefore, the terminal station B recognizes that the data has been sent from the terminal station A to the repeater between the terminal stations DB based on the identification information included in the monitoring control signal. Then, it is determined that it is meaningless to further transfer the monitor control signal, and the transfer of the monitor control signal is stopped. This prevents one repeater from receiving the same monitoring control signal twice.

Further, considering the configuration in FIG. 15, since two optical fiber pairs are used, four
Two optical amplifiers are equipped. However, not all four optical amplifiers can receive the supervisory control signal.
Therefore, it is possible to use the repeater of FIG. 16 to solve this problem.

That is, FIG. 16 shows a configuration in which the supervisory control signal can be received even in the optical amplifier of the repeater which cannot directly receive the supervisory control signal. One optical amplifier 11
When 0 receives the supervisory control signal, it transfers the supervisory control signal from the optical amplifier 110 to the other optical amplifiers 111 to 113. This makes it possible to receive the supervisory control signal even in an optical amplifier that cannot directly receive the supervisory control signal.

Further, FIG. 17 shows an example of the configuration of an optical transmitting / receiving terminal capable of switching the signal wavelength modulated by the monitoring control signal depending on the location of the repeater to be monitored, that is, capable of routing the monitoring control signal. is there.

[0133] If the repeater that is between end stations A-B sends a supervisory control signal, and sends the modulated signal light having a wavelength W ₂ in the monitor control signal. Further, when the repeater is in between the optical multiplexing and demultiplexing device 1 end station C sends a monitoring control signal is sent by modulating the signal light having a wavelength W ₃ in the monitor control signal.

[0134] Therefore, between the end stations A- optical multiplexing and demultiplexing device 1 it is possible that the two wavelengths W ₂ and W ₃ is used for monitoring and control. In this case, one of the wavelengths (W _{2 in} the example of FIG. 17) can be set in advance by the switch 20 or the like so as to use one of the wavelengths (W _{2 in} the example of FIG. 17) for monitoring the repeater in this section.

Alternatively, by providing an optical filter for extracting only the supervisory control signal light to be received by the repeater, the supervisory control signal can be received by paying attention to only one wavelength of the signal light. It is possible to This makes it easy to design and manufacture the optical filter provided in the repeater.

Here, in each of the embodiments described in detail above, the optical multiplexing / demultiplexing device has been described as a configuration schematically shown in FIG. That is, in FIG. 18A, it is configured to include three sets of add / drop circuits ADM1 to ADM3. Each add / drop circuit is configured as shown in FIG. 19 as an example, and has two input terminals I1 and I2 and two output terminals O1 and O2.

Further, in FIG. 19, the add / drop circuit has circulators 100 and 101 and fiber grating filters 102 and 103. The fiber grating filters 102 and 103 are filters having a property of reflecting light of a specific wavelength.

[0138] Thus, a fiber grating filters 102 and 103 for example, when designed to reflect light of wavelength lambda _1, when the wavelength multiplex signals of four wavelengths lambda ₁ to [lambda] ₄ is input, the fiber grating filter 10
The input light of wavelength λ ₁ reflected by 2 is branched (dropped) by circulator 100 in a direction different from the input.

The light having the wavelength λ ₁ input to the circulator 101 is
And is added (added) to the wavelength multiplexed signal of wavelengths λ _{2 to} λ ₄ through the circulator 101.
Therefore, the wavelength λ is output as the output of the circulator 101.
Wavelength multiplexed signals ₁ to [lambda] ₄ appears.

When three such add / drop circuits are used to form the optical branching circuit 1 as shown in FIG. 18A, as shown in the previous embodiment, the branch / insertion connected to the terminal station C is performed. The transmission line can be a pair of fiber transmission lines. However, in such a case, 1 is connected to the terminal station C.
It is necessary to set the upstream and downstream of the transmission path of the pair of fibers to different wavelengths.

On the other hand, if the configuration shown in FIG. 18B is used by using two add / drop circuits, the add / drop transmission line connected to the terminal station C has two pairs of fiber transmission lines C1 , C2, the light traveling from terminal station A to C (upward direction) and the light traveling from terminal station C to A (downward direction) can be set to the same wavelength.

Further, in the above description, a passive WDM network in which signal wavelength conversion (optical cross connect and wavelength routing) is not mainly performed by an optical multiplexer / demultiplexer is described as a model system. However, the present invention can achieve the same effect even when an active WDM network is used.

Further, in the above-described embodiment, the network of the linear type and the combination thereof has been described as a model system. However, the present invention can be applied to any network having these basic types. For example, as in the case of FIG. 24, by adopting the configuration of FIGS. 11 and 12, even in a ring network, a supervisory control signal can be sent from any terminal to the repeater.

[0144]

As described above, according to the present invention, it becomes possible to send a supervisory control signal from an arbitrary terminal to an arbitrary repeater in a WDM network.

Further, according to the present invention, the number of signal wavelengths used for supervisory control can be made within two wavelengths, and the signal wavelength for supervisory control can be used for the main signal as needed. Therefore, the transmission wavelength band can be used effectively.

Further, the number of signal wavelengths used for monitoring and control is set to 2
Since the wavelength can be within the wavelength range, an optical filter is used for the monitoring control signal receiving section of the repeater, and the reception power of the monitoring control signal in the repeater is increased by extracting only the signal light for monitoring control. Becomes possible. That is, it becomes easy for the repeater to receive the monitoring control signal.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating transfer of a supervisory control signal as a first feature of the present invention.

FIG. 2 is a diagram illustrating a supervisory control signal transfer function in a terminal station.

FIG. 3 is a diagram illustrating an example of forming an optical path so that a monitoring control signal passes through all transmission paths.

FIG. 4 is a diagram illustrating an example of assignment of wavelengths for monitoring and control.

FIG. 5 is a conceptual diagram showing the first embodiment of the present invention.

FIG. 6 is an example block diagram for the embodiment of FIG. 5;

FIG. 7 is a block diagram of a principle configuration for realizing a function of transferring a supervisory control signal in the optical transmitting / receiving terminal.

8 is a block diagram showing a configuration example of an optical transmitting / receiving terminal having a monitoring control signal transfer function configuration shown in FIG. 7;

9 is a block diagram showing another example of the configuration of the optical transmitting / receiving terminal having the supervisory control signal transfer function configuration shown in FIG. 7;

FIG. 10 is a block diagram showing a configuration example in which a repeater in a network can be monitored from one terminal station.

FIG. 11 is a block diagram of an embodiment for forming an optical path for a supervisory control signal.

FIG. 12 is a block diagram of an embodiment in which the embodiment of FIG. 11 is modified.

FIG. 13 is a block diagram of an embodiment in which the embodiment of FIG. 12 is further modified.

FIG. 14 is a configuration example that realizes branching and coupling of signal light for monitoring and control in the optical multiplexer / demultiplexers 1 and 2 in FIG.

FIG. 15 is a block diagram of an embodiment in which upstream and downstream optical paths connecting two adjacent terminal stations are formed, and a signal light modulated by a supervisory control signal is passed.

FIG. 16 is a block diagram of a configuration example in which a monitoring control signal can be received even in an optical amplifier of a repeater that cannot directly receive a monitoring control signal.

FIG. 17 is a block diagram illustrating a configuration example of an optical transmitting / receiving terminal station capable of routing a supervisory control signal.

FIG. 18 is a diagram illustrating a configuration example of an optical multiplexing / demultiplexing device in each embodiment.

19 is a block diagram illustrating a configuration example of an optical ADM included in the optical multiplexer / demultiplexer of FIG. 18;

[Figure 20] Point-to-point
FIG. 3 is a diagram illustrating a T) type transmission path configuration.

FIG. 21 is a diagram illustrating an operation example of the optical amplification repeater in the superimposition method of the monitoring control signal.

FIG. 22 is a diagram illustrating an operation example of an optical amplifying repeater in a wavelength multiplexing method of a supervisory control signal.

FIG. 23 is a diagram illustrating an example of a serial type optical transmission system networked using a wavelength division multiplexing (WDM) technique.

FIG. 24 is a diagram illustrating an example of a ring-type optical transmission system networked using wavelength division multiplexing (WDM) technology.

25 is a diagram illustrating an example of a passage path of a monitoring control signal in the optical transmission system of FIG.

26 is a diagram illustrating another example of the passage of the monitoring control signal in the optical transmission system of FIG.

FIG. 27 is a diagram showing still another example of the passage of the monitoring control signal in the optical transmission system of FIG. 23;

[Explanation of symbols]

 1, 2 optical multiplexer / demultiplexer OPC1, OPC2 optical fiber pair 3 modulator 4 optical demultiplexer 5 supervisory control signal processor 50, 60 photoelectric converter 51, 61 supervisory control signal reproducer 52, 62 signal processor 6 main signal Processing unit 7 Laser diode 8 Optical amplifier 10 Demultiplexer 11 Combiner

Claims (29)

[Claims] 1. An optical multiplexer / demultiplexer comprising: at least one optical multiplexer / demultiplexer; a plurality of terminal stations connected to the at least one optical multiplexer / demultiplexer through an optical transmission line; and a plurality of optical repeaters disposed on the optical transmission line. The second terminal station receives a monitoring control signal transmitted from the first terminal station of the plurality of terminal stations through the optical multiplexer / demultiplexer, and receives the received monitoring control signal. A monitoring and controlling system for a wavelength division multiplexing communication network, wherein the system is configured to transfer the data to a third terminal through an optical multiplexer / demultiplexer. 2. The supervisory control system according to claim 1, wherein the first terminal station sends the supervisory control signal to the second terminal station using a communication line allocated for main signal data. Upon receiving the signal, the second terminal modulates at least one wavelength of signal light by the monitoring control signal, multiplexes the modulated at least one wavelength of signal light with another signal light, and modulates the main signal. A monitoring and control system for a wavelength division multiplexing communication network, wherein the data is transferred to a third terminal station using a communication line allocated for data. 3. The monitor according to claim 1, wherein the first terminal modulates at least one wavelength of the signal light with the monitoring control signal, and converts the plurality of wavelengths of the signal light including the modulated signal light into wavelengths. Multiplexes the signal to the second terminal station, the second terminal station selects the wavelength from the received signal light, receives the monitor control signal, and receives at least one wavelength of the monitor control signal by the received monitor control signal. The signal light is modulated, and the signal light having a plurality of wavelengths including the modulated signal light is wavelength-multiplexed.
A monitoring and control system for a wavelength division multiplexing communication network, wherein the system control information is transferred to a terminal station. 4. The first terminal station according to claim 1, wherein the first terminal station modulates at least one wavelength of signal light with the supervisory control signal and sends the modulated signal light to the second terminal station. And converting the wavelength of the received signal light to a different wavelength and transferring the converted signal light to the third terminal station. 5. The monitoring device according to claim 3, wherein the second terminal station performs photoelectric conversion on at least one wavelength of the signal light modulated by the monitoring control signal sent from the first terminal station. A supervisory control system for a wavelength division multiplexing communication network, wherein a supervisory signal is reproduced, and a signal light having a wavelength different from the at least one wavelength is modulated by the reproduced supervisory control signal. 6. The system according to claim 3, wherein the second terminal station determines whether or not the transfer is necessary based on the monitor control signal, and does not transfer the monitor control signal when the transfer is unnecessary. A monitoring and control system for a wavelength division multiplexing communication network. 7. The monitoring control signal according to claim 6, wherein the monitoring control signal includes identification information for identifying a signal transmitted from any terminal to which optical repeater, and the second terminal includes: The identification information of the supervisory control signal is read, and the supervisory control signal is transferred when the corresponding optical repeater is present in the direction in which the signal is transmitted, and when the relevant repeater does not exist, the supervisory control signal is transmitted. A supervisory control system for a wavelength division multiplexing communication network, characterized in that transmission of data is not performed. 8. The optical communication system according to claim 1, wherein a combination of optical paths is formed so that the monitor control signal transmitted from the first terminal station passes through the plurality of optical repeaters. Characteristic monitoring and control system for WDM communication networks. 9. A first and second terminal, a first optical transmission line connecting the first and second terminal, and at least one optical multiplexer / demultiplexer provided in the first optical transmission line. And at least one third terminal connected to the at least one optical multiplexer / demultiplexer through a second optical transmission line, respectively, and an optical repeater disposed on the first and second optical transmission lines. Further, in a wavelength division multiplexing communication network for performing optical wavelength division multiplexing communication between the first and second terminal stations and the at least one third terminal station, the first terminal station is adjacent to the third terminal station. Sending an optical signal superimposed with a supervisory control signal for the optical repeater to one of the terminal stations; the third terminal station sequentially transmits an optical signal superimposed with the supervisory control signal to an adjacent terminal station; Further, an optical signal in which the monitor control signal is superimposed is transferred from the last terminal station of the third terminal station to the adjacent second terminal station, End station of said second, Monitoring of WDM communication network, characterized in that the optical path so as transmitting light signal obtained by superimposing the monitoring control signals to the first terminal station is formed. 10. The optical signal according to claim 9, wherein the optical signal superimposed with the monitor control signal passing between the first and second terminal stations and at least one third terminal station is an optical signal having the same wavelength. A monitoring and control system for a wavelength division multiplexing communication network. 11. A first and second terminal station, a first upstream and downstream optical transmission line connecting the first and second terminal stations, and a first upstream and downstream optical transmission line. At least one optical multiplexer / demultiplexer;
At least one third terminal connected to the at least one optical multiplexer / demultiplexer through second upstream and downstream optical transmission lines, respectively, and disposed on the first and second upstream and downstream optical transmission lines; A wavelength division multiplexing communication network for performing optical wavelength division multiplexing communication between the first and second terminal stations and the at least one third terminal station, the first and second terminal stations comprising: A terminal and each of the at least one third terminal are connected to the adjacent terminal through the at least one optical multiplexer / demultiplexer by a path passing through a corresponding upstream and downstream optical transmission line. A monitoring and control system for a wavelength division multiplexing communication network, which transmits an optical signal superimposed with a monitoring and control signal. 12. The apparatus according to claim 11, wherein said second terminal station and said at least one third terminal station output an optical wavelength of said input supervisory control signal at a wavelength different from an input wavelength. A wavelength division multiplexing communication network monitoring and control system. 13. A supervisory control system for a wavelength division multiplexing communication network, comprising: a first terminal, an optical multiplexer / demultiplexer for optically demultiplexing an optical signal sent from the first terminal, and an optical multiplexer / demultiplexer. Second and third terminal stations for receiving the branched optical signals; and the first and second terminal stations leading to the optical multiplexer / demultiplexer, and branched from the optical multiplexer / demultiplexer to receive the second and third terminals. A first optical path reaching each of the first and second terminal stations; and a second optical path from each of the second and third terminal stations to the optical multiplexer / demultiplexer, which is combined by the optical multiplexer / demultiplexer to form the first terminal station. A supervisory control system for a wavelength-division multiplexing communication network, characterized in that a second optical path leading to the optical path is formed, and signal light modulated by a supervisory control signal is passed through the formed first and second optical paths. 14. A first and second terminal station, and at least one first optical multiplexer / demultiplexer provided in an upstream and downstream optical transmission line connecting the first and second terminal stations, A first path having at least one third terminal connected to the at least one first optical multiplexer / demultiplexer through upstream and downstream optical transmission paths, respectively, a fourth and a fifth terminal; At least one second optical multiplexer / demultiplexer provided in the upstream and downstream optical transmission lines connecting the fourth and fifth terminal stations; An optical wavelength division multiplex communication having a second path having at least one sixth terminal station connected through a downstream optical transmission line, wherein the first path and the second path perform optical wavelength division multiplex communication. In the network, the first terminal is an optical signal in which a supervisory control signal is superimposed on one of the adjacent third terminals. The third terminal sequentially transmits the optical signal in which the supervisory control signal is superimposed to the adjacent terminal, and further transmits the second terminal adjacent to the third terminal from the last terminal of the third terminal. An optical signal having the monitor control signal superimposed thereon is transmitted to a station, the second terminal station sends an optical signal having the monitor control signal superimposed to the four terminal stations, and the fourth terminal station has: An optical signal in which a supervisory control signal is superimposed is sent to one of the adjacent sixth terminal stations, and the sixth terminal station
An optical signal in which the supervisory control signal is superimposed is sequentially transferred to an adjacent terminal station, and further, the optical signal in which the supervisory control signal is superimposed on a fifth terminal station adjacent to the last terminal station of the sixth terminal station. An optical wavelength division multiplexing communication network for performing optical wavelength division multiplexing communication, wherein an optical path is formed so as to transfer a signal. 15. The supervisory control system for a wavelength division multiplexing network according to claim 14, wherein the wavelengths of the superimposed supervisory control signals passing between the terminal stations are light having the same wavelength. 16. A plurality of optical multiplexer / demultiplexers connected on a ring by an optical transmission line, and a plurality of terminal stations connected to each of the plurality of optical multiplexer / demultiplexers. In a wavelength division multiplexing communication system for performing wavelength division multiplexing, an optical path is formed such that light on which a supervisory control signal is superimposed passes between the plurality of adjacent terminal stations through the plurality of optical multiplexer / demultiplexers. Characteristic monitoring and control system for WDM networks. 17. The supervisory control system for a wavelength division multiplexing network according to claim 16, wherein the light on which the supervisory control signal is superimposed uses light having the same wavelength at each terminal station. 18. A plurality of optical multiplexers / demultiplexers, a plurality of terminal stations connected to each of the plurality of optical multiplexers / demultiplexers, and the plurality of optical multiplexers / demultiplexers connected by an upstream optical transmission line and a downstream optical transmission line. In a wavelength division multiplexing communication system which is connected in a ring shape and performs optical wavelength division multiplexing communication between the terminal stations, an optical signal on which the monitor control signal is superimposed is connected to the adjacent terminal via the optical multiplexer / demultiplexer. A supervisory control system for a wavelength-division multiplexing network, characterized in that a path connected between stations via an upstream optical transmission line and a path connected between adjacent terminal stations via the optical multiplexer / demultiplexer are connected via a downstream optical transmission line. . 19. The supervisory control of a wavelength division multiplexing network according to claim 18, wherein a wavelength of said supervisory control signal flowing through said upstream optical transmission line and a wavelength of light flowing through said downstream optical transmission line are different from each other. system. 20. A plurality of optical multiplexers / demultiplexers, a plurality of terminal stations connected to each of the plurality of optical multiplexers / demultiplexers, and the plurality of optical multiplexers / demultiplexers connected by an upstream optical transmission line and a downstream optical transmission line. In a wavelength division multiplexing communication system which is connected in a ring shape and performs optical wavelength division multiplexing communication between the terminal stations, an upstream and downstream optical path connecting two adjacent terminal stations is formed, and the upstream and downstream paths are formed. A wavelength division multiplexing network, wherein the optical fiber is assigned to different fibers, and an optical main signal modulated by a supervisory control signal is passed through the optical path. 21. The supervisory control system for a wavelength division multiplexing communication network according to claim 20, wherein the signal wavelengths of the 2N optical paths selected for transmitting supervisory control signals are the same. 22. The signal light for monitoring and controlling according to claim 1, wherein the signal light for monitoring and control is modulated by a data signal.
A supervisory control system for a wavelength division multiplexing communication network, wherein a supervisory control signal is superimposed on the data signal. 23. A supervisory control system for a wavelength division multiplexing communication network according to claim 1, wherein the supervisory control signal light is dedicated to supervisory control signals. 24. The monitoring control signal receiving section of a repeater according to claim 1, wherein the monitoring control signal receiving section of the repeater has a filter that transmits only the signal light modulated by the monitoring control signal. Monitoring and control system for WDM communication networks. 25. The optical repeater according to claim 1, wherein the optical repeater comprises a plurality of optical amplifiers, wherein each optical amplifier receives the supervisory control signal, and the other optical amplifier controls the other optical amplifier. A wavelength division multiplexing communication network system having a function of transferring a signal. 26. The at least one optical multiplexer / demultiplexer, a plurality of terminal stations connected to the at least one optical multiplexer / demultiplexer through an optical transmission line, and a plurality of terminal stations placed on the optical transmission line An optical repeater, wherein the second terminal receives, via the optical multiplexer / demultiplexer, a monitoring control signal for the optical repeater sent from a first terminal of the plurality of terminals, and The supervisory control signal is configured to be transferred to the third terminal through the optical multiplexer / demultiplexer, and the optical wavelength of the supervisory control signal passing between the terminals is the same for all the terminals. A wavelength division multiplexing network supervisory control system using wavelengths. 27. The wavelength according to claim 18, wherein the monitor control signal flowing through the upstream optical transmission line and the monitor control signal flowing through the downstream optical transmission line use the same optical wavelength. Monitoring and control system for multiple networks. 28. A wavelength division multiplexing communication network according to claim 1, wherein the signal wavelength modulated by the supervisory control signal is switchable according to the position of the repeater to be monitored. Monitoring and control system. 29. The monitoring of a wavelength division multiplexing communication network according to claim 28, wherein each repeater is provided with an optical filter for extracting only the supervisory control signal light to be received in said repeater. Control system.