JP3464749B2 - Wavelength division type optical communication path - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a switching device (cross-connect device) for switching wavelength-multiplexed signal light input from a plurality of input optical transmission lines and cross-connecting to a predetermined output optical transmission line. The present invention relates to a wavelength division type optical communication path that includes a system and a standby system, and has a redundant configuration that does not require switching from the standby system to the active system (hereinafter referred to as "switchback") at the time of failure recovery.

[0002]

2. Description of the Related Art FIG. 10 shows the configuration of a conventional wavelength division type optical communication path using an optical space switch. Here, in the case where the number of input / output optical transmission lines is N and the number of wavelength multiplexing is M, M × N signal channels are replaced with each other with the same wavelength.
In the figure, the input optical transmission line 11 _j (j = 1, 2, ..., N)
The wavelength-multiplexed signal light of M waves input from is demultiplexed into signal lights of wavelengths λ _{1 to} λ _{M by} the optical demultiplexer 21 _j of M output. The signal light of wavelength λ _i (i = 1, 2, ..., M) is input to the optical space switch 51 _i having N inputs and N outputs, and a predetermined output destination is selected for each. The signal light output from the output port j of the optical space switch 51 _i is wavelength-multiplexed by the M-input optical multiplexer 22 _j and output to the output optical transmission line 12 _j .

FIG. 11 shows another structure of a conventional wavelength division type optical communication path using an optical space switch. Here, in the case where the number of input / output optical transmission lines is N and the number of wavelength multiplexing is M, a configuration is shown in which M × N signal channels are switched while performing wavelength conversion. In the figure, the input optical transmission line 11 _j (j = 1,
2, ..., N), the wavelength multiplexed signal light of M waves is
The optical demultiplexer 21 _j of M output demultiplexes the signal light of each wavelength of λ ₁ to λ _M , and the corresponding wavelength conversion circuits 15 _ji (i
, 1, 2, ..., M) to the optical space switch 52 _j having M inputs (2M−1) output. Wavelength conversion circuit 15
_{In ji} , each signal channel is converted into a predetermined wavelength so that the signal wavelengths do not have the same wavelength on the output optical transmission line 12 _j . The signal light of each wavelength is an optical space switch 5 of M input (2M-1) output.
2 _j and N input N output optical space switches 51 _{1 to} 51
Predetermined output destinations are respectively selected via _2M-1 . The signal light output from the optical space switch 51 ₁ ~51 _2M-1 output port j is output to the (2M-1) is merged with the input of the optical power multiplexer 44 _j output optical transmission line 12 _j.

Here, the difference between the optical demultiplexer and the optical combiner will be briefly described. The optical demultiplexer has a configuration in which signal light is coupled to one output port by utilizing the difference in reflection angle for each wavelength due to the grating. The optical combiner has a configuration in which signal light is coupled to one output port using an optical coupler. It is possible to replace the optical multiplexer with the optical multiplexer, but the optical multiplexer has a larger insertion loss than the optical multiplexer.

Incidentally, the conventional wavelength division type optical communication path shown in FIG. 10 or FIG. 11 does not have a redundant configuration with respect to the optical space switch. Therefore, when the optical space switch fails, the signal channel accommodated in the optical space switch needs to be switched to the backup path in the entire network or in the nodes before and after. Ie 1
The influence range of the two optical space switches on the failure is large, and the reliability against the failure cannot be said to be high.

Here, the prior art shown in FIG. 10 or FIG.
Redundant Structure of Optical Space Switch in Wavelength Division Optical Communication Line
An example is shown in FIG. 12 or FIG. In FIG.
If there is no failure in the component parts, the input optical transmission line 11_jOr
The M-wavelength multiplexed signal light input from the
1) Corresponding to each via the output optical space switch 61
Optical demultiplexer 21_jAre input to the respective wavelength λ₁~ Λ _M
Demultiplexed into the signal light of. Each optical demultiplexer 21_jWas demultiplexed with
The signal light is an optical space switch 64 of M input (M + 1) output.
_jThrough the wavelength λ_iSignal light is (N + 1) input N output
Optical space switch 53_iAre input to the specified output
The destination is selected. Optical space switch 53_iOutput port
The signal light output from j is an (M + 1) input optical combiner.
43_jOutput optical transmission line 12_jIs output to
It At this time, the optical demultiplexer 21_{N + 1}, M input (M + 1) output
Power light space switch 64_{N + 1}, (N + 1) input N output
Optical space switch 53_{M + 1}, And the dashed line in the figure
It is a system and is not used.

Next, a case where the optical space switch 53 ₁ fails will be described. Of the signal lights input to the M input (M + 1) output optical space switches 64 ₁ to 64 _N , the wavelength λ
All ₁ signal lights are guided to the (N + 1) input N output optical space switch 53 _{M + 1} , and the optical space switch 53 ₁ selects the output optical transmission line 12 _j selected before the failure. Thus, even if the optical space switch 53 ₁ fails, it can be switched without affecting other signal channels. Further, even if the failure of the optical space switch 53 ₁ is repaired, it is not necessary to switch back the channel accommodated in the optical space switch 53 _{M + 1} to the optical space switch 53 ₁ , and the optical space switch 53 ₁ becomes a standby system. Become.

In FIG. 13, when there is no failure in each component, the M-wavelength multiplexed signal light input from the input optical transmission line 11 _j passes through the N-input (N + 1) -output optical space switch 61. Are input to the corresponding optical demultiplexers 21 _j and demultiplexed into signal lights of wavelengths λ _{1 to} λ _M , respectively. The signal light demultiplexed by each optical demultiplexer 21 _j is converted into a predetermined wavelength by the corresponding wavelength conversion circuit 15 _ji , and the optical space switches 52 _j and (N + 1) with M inputs (2M−1) outputs are converted. ) Input N output optical space switches 53 _{1 to} 53
Predetermined output destinations are respectively selected via _2M-1 . The signal lights output from the optical space switches 53 _{1 to} 53 _2M-1 are wavelength-multiplexed by the (2M-1) input optical combiner 44 _j and output to the output optical transmission line 12 _j . At this time, the optical demultiplexer 21 _{N + 1} , the wavelength conversion circuit 15 _{(N + 1) i} , the M input (2M-
1) The output optical space switch 52 _{N + 1} and the broken line path in the figure are spare systems and are not used.

Next, the optical space switch 52₁When
The case will be described. Optical space switch 52₁Housed in
The signal channel that is being used is the input optical transmission line 11₁Entered from
It was the one. Therefore, N input (N + 1) output optical sky
The setting of the inter-switch 61 is changed and the input optical transmission line 11₁Or
The wavelength division multiplexed signal light input from the optical demultiplexer 21_{N + 1}Led to
Ku. Optical demultiplexer 21_{N + 1}The signal light demultiplexed by is wavelength converted
Circuit 15 _{(N + 1) i}Are converted to the respective predetermined wavelengths by
Power (2M-1) output optical space switch 52_{N + 1}Entered in
Be done. Optical space switch 52_{N + 1}Is the optical space switch before the failure.
Switch 52₁Is set to the same as the setting of, and each signal light is (N +
1) Input N output optical space switch 53₁~ 53_2M-1,light
Merger 44_jOutput optical transmission line 12_jIs output to
It As a result, the optical space switch 52₁Even if
You can switch without affecting other signal channels.
You can

Further, even if the failure of the optical space switch 52 ₁ is repaired, it is not necessary to switch back the channel accommodated in the optical space switch 52 _{N + 1} to the optical space switch 52 ₁ .
Therefore, it is not necessary to change the setting of the optical space switch 61, and the optical demultiplexer 21 ₁ , the wavelength conversion circuit 15 _1i , and the optical space switch 52 ₁ serve as a standby system. The (N + 1) input N output optical space switches 53 _{1 to} 532 _M-1 have a redundant configuration as a whole, and even if one of them fails, the preceding M input (2M-1) output optical space switches are provided. Switches 52 _{1 to} 52 _{N + 1}
It is possible to form an optical communication path that avoids a faulty part by switching the output ports of.

[0011]

As described above, FIG.
The wavelength division type optical communication path shown in FIG. 0 or FIG. 11 can easily take a redundant configuration like the wavelength division type optical communication path shown in FIG. 12 or FIG. By the way, the circuit scale of the (N + 1) input N output optical space switch 53 depends on the number N of input / output optical transmission lines, but the number depends on the number M of wavelength multiplexing. On the other hand, the number of M input (M + 1) output optical space switches 64 and the number of M input (2M-1) output optical space switches 52 depend on the number N of input / output optical transmission lines.
Therefore, when the number N of input / output optical transmission lines is changed due to fluctuations in traffic demand, the number of optical space switches 64 and 52 may be changed according to N.
3 needs to replace everything regardless of N. Alternatively, if a large-scale one is used in advance, the wavelength multiplexing number M
It is necessary to prepare only the number according to. That is, the conventional optical space switch 53 of the wavelength division type optical communication path shown in FIG. 12 or FIG. 13 needs a number depending on the number of wavelength multiplexing M regardless of the increase or decrease of the number N of input / output optical transmission lines. It can be said that the scalability is low with respect to the increase in the number of input / output optical transmission lines.

According to the present invention, in a wavelength division type optical communication line having a redundant configuration in which it is not necessary to switch back from the standby system to the working system at the time of failure recovery, the scalability with the increase of the input / output optical transmission lines is achieved with a small amount of hardware. It is an object of the present invention to provide a wavelength division type optical communication path capable of improving the communication efficiency.

[0013]

According to a first aspect of the present invention, there is provided a wavelength division type optical communication path having N inputs (N) connected to N input optical transmission paths.
+ H) output optical space switch, (N + H) M output optical demultiplexers, (N + H) M input N output converging switches, and N output optical transmission lines connected to N Of (N
+ H) input optical multiplexer, and H optical demultiplexers and junction switches are used as a standby system.

When the converging type switch fails, it is switched to any one of the H optical demultiplexers and the converging type switch prepared as a standby system via the optical switch, so that the failure occurs in the own node. It can be avoided. Further, since it is not necessary to switch back even after the recovery of the failed switch, the interruption of communication can be avoided. Furthermore, (N
+ H) M input / N output merging type switches depend on the number of input / output optical transmission lines N, so the number of input / output optical transmission lines N can be increased or decreased with the minimum required configuration. can do. That is, the expandability with respect to the increase or decrease in the number of input / output optical transmission lines can be improved.

In the wavelength division type optical communication path of claim 2, N input (N +) input ports are connected to N input optical transmission paths.
H) output first optical space switch and (N + H) M
Output optical demultiplexer, (N + H) M input (N + H ) output merging type switches, (N + H ) (N + H) input optical merging devices, and N output ports A second optical space switch having (N + H ) inputs and N outputs connected to the transmission line is used, and H optical demultiplexers, merging switches, and optical merging devices are used as a standby system.

When the converging type switch fails, the failure can be avoided in the own node via the first optical switch as in the wavelength division type optical communication path of claim 1. If the optical combiner fails, through the second optical switch,
A failure can be avoided in the own node by switching to any one of the H optical multiplexers prepared as a standby system. Further, since it is not necessary to switch back even after the recovery of the failed optical multiplexer, it is possible to avoid communication interruption. Further, the (N + H) M-input / N-output merging type switch depends on the number N of input / output optical transmission lines in terms of the circuit scale and the number thereof, and therefore, the minimum necessary amount for increasing or decreasing the number N of input / output optical transmission lines The configuration can accommodate this. That is, the expandability with respect to the increase or decrease in the number of input / output optical transmission lines can be improved.

[0017] Wavelength division type optical communication path according to claim 3, in place of the first optical space switch in a wavelength division type optical communication path according to claim 2 (N + H) input (N + H) third space optical output < A switch is used instead of the second optical space switch (N +
H) Input (N + H) output fourth optical space switch is used to measure the signal characteristics between the H output ports of the fourth optical space switch and the H input ports of the third optical space switch, respectively. Connect the parts. As a result, it is possible to simultaneously deal with the failure of the merging type switch or the optical merging device and monitor the signal channel of the input / output optical transmission line.

Further, between the optical demultiplexer and the converging type switch, M pieces of regenerative repeater circuits for amplifying the demultiplexed signal light of each channel, waveform shaping and other regenerating processing, or converting wavelengths. M wavelength conversion circuits may be inserted (claims 4 and 5).

[0019]

DETAILED DESCRIPTION OF THE INVENTION

(First Embodiment) FIGS. 1 and 2 show a first embodiment of a wavelength division type optical communication path of the present invention. In the figure, input optical transmission lines 11 _j (j = 1, 2, ..., N) each transmit wavelength-multiplexed signal light of M waves. The input optical transmission line 1 is connected to the input port j of the N input (N + 1) output optical space switch 61.
1 _j is connected to the output port j, and the optical demultiplexer 2 with M output is connected to the output port j.
An M-input / N-output merging type switch 31 _j is connected via 1 _j , and a standby optical demultiplexer 21 is connected to the output port N + 1.
And coupling the switch 31 N _{+ 1} of M input N output is connected via the _{N + 1.} An (N + 1) -input optical combiner 41 _j connected to the output optical transmission line 12 _j is connected to each output port j of the combining switches 31 _{1 to} 31 _{N + 1} .

The feature of this embodiment is that the M input (M + 1) output optical space switch 6 in the redundant configuration example shown in FIG.
4 ₁ to 64 _{N + 1} and (N + 1) input N output optical space switches 53 _{1 to} 53 _{M + 1} are replaced by M input N output merge switches 31 _{1 to} 31 _{N + 1} (M + 1) In place of the input optical combiners 43 ₁ to 43 _N , (N + 1) input optical combiners 41 _{1 to} 41 _N are used.

Here, an example of operation when there is no failure in each component will be described with reference to FIG. Optical demultiplexer 21
The merged switch 31 _{N + 1} having _{N + 1} and M inputs and N outputs is used as a standby system. The wavelength-multiplexed signal light of M waves input from the input optical transmission line 11 _{j is} input to the corresponding optical demultiplexer 21 _j via the N input (N + 1) output optical space switch 61, and the wavelength λ ₁ ~ Demultiplexed to λ _M signal light. The signal light demultiplexed by each optical demultiplexer 21 _j is input to the corresponding M input N output merging type switch 31 _j , and is distributed to the output port j corresponding to the output optical transmission line 12 _j . Signal light output from the merging switch 31 _j merges with optical combiners 41 _j provided to each output optical transmission line 12 _j, it is outputted to the output optical transmission path 12 _j.

Next, the merging type switch 31₁When
The case will be described with reference to FIG. Merge type switch
31₁The signal channel accommodated in the input optical transmission line
11₁It was input from. Therefore, N input (N
+1) Change the setting of the output optical space switch 61 and input
Optical transmission line 11₁Wavelength division multiplexed signal light input from
Bowl 21_{N + 1}Lead to. Optical demultiplexer 21_{N + 1}Signal demultiplexed by
Light is a merge switch 31_{N + 1}Entered in. Confluence type
Switch 31_{N + 1}Is the confluent switch 31 before failure ₁Set up
The signal light is set to be the same as_jJoin at
And output optical transmission line 12_jIs output to. This allows
Flow type switch 31₁Even if a fault occurs, the other signal channels
You can switch without affecting.

Further, even if the malfunction of the merge switch 31 ₁ is repaired, it is not necessary to switch back the channel accommodated in the merge switch 31 _{N + 1} to the merge switch 31 ₁ .
Therefore, it is not necessary to change the setting of the optical space switch 61, and the optical demultiplexer 21 ₁ and the merging type switch 31 ₁ serve as a standby system. It should be noted that the present embodiment shows a configuration in which one spare set is provided for the N working sets. Similarly, to provide a spare H set for the working N sets, the optical space switch 6
This is possible by providing (N + H) the number of output ports of 1 and (N + H) each of the optical demultiplexer 21 and the merging type switch 31 and setting the number of input ports of the optical merging unit 41 to (N + H).

Also, the working N sets shown in FIGS. 1 and 2 and the spare 1
By setting one set as a unit and preparing this as an H unit, it is possible to correspond to a total of (N × H) input / output optical transmission lines. However, the number of output ports of the merge-type switch 31 is (N × H), and the number of input ports of the optical combiner 41 is ((N
+1) × H). In this case, there is a spare H set for the working (N × H) set.

(Second Embodiment) FIGS. 3 and 4 show a second embodiment of the wavelength division type optical communication path of the present invention. The feature of this embodiment is that it can cope with the failure of the optical combiner 41 in the first embodiment shown in FIGS. That is, M input (N + 1) as a merge switch
Using the output merging switches 32 _{1 to} 32 _{N + 1} , (N +
1) Input optical multiplexers 41 _{1 to} 41 _{N + 1} and output optical transmission line 1
An optical space switch 62 having (N + 1) inputs and N outputs is provided between the two and 2 _j .

Here, an operation example when there is no failure in each component will be described with reference to FIG. Optical demultiplexer 21
_{N + 1} , the merging type switch 32 _{N + 1} , and the optical merging device 41 _{N + 1} are used as a standby system. The wavelength-multiplexed signal light of M waves input from the input optical transmission line 11 _{j is} input to the corresponding optical demultiplexer 21 _j via the N input (N + 1) output optical space switch 61, and the wavelength λ ₁ ~ Demultiplexed to λ _M signal light. The signal lights demultiplexed by the respective optical demultiplexers 21 _j are merged type switches 32 _{j having} corresponding M input (N + 1) outputs.
And is distributed to the output port j corresponding to the output optical transmission line 12 _j . The signal lights output from the merging type switch 32 _j are merged by the optical merging unit 41 _j provided for the output optical transmission line 12 _j , and the (N + 1) input N output optical space switch 62, The wavelength multiplexed signal light input to the input port j is output to the output optical transmission line 12 _j .

Next, a case where the optical combiner 41 ₁ fails will be described with reference to FIG. The signal channel accommodated in the optical combiner 41 ₁ is output to the output optical transmission line 12 ₁ from each output port 1 of the combined switch 32 _j . Therefore, of the N × M signal channels accommodated in the merge switch 32 _j , the merge switch 32
All the settings of the signal channel output to the output port 1 of _j are switched to the output port (N + 1). This allows
The signal light that has been input to the optical combiner 41 ₁ before the failure can be input to the optical combiner 41 _{N + 1} . Optical combiner 41
_The signal light output from _{N + 1} is input to the input port (N + 1) of the (N + 1) input N output optical space switch 62, so that the signal light is output to the output port 1.
The setting of the (N + 1) input N output optical space switch 62 is changed. At this time, the setting of the N input (N + 1) output optical space switch 61 is not changed. As a result, the optical combiner 4
Even if 1 ₁ fails, it can be switched without affecting other signal channels.

Further, the optical combiner 41₁Has been repaired
Also, optical combiner 41_{N + 1}The channels housed in
Sink 41₁There is no need to switch back to. Therefore, the light space
It is not necessary to change the setting of the switch 62, and the optical demultiplexer 2
1_{N + 1}, Merge switch 31 _{N + 1}, Optical combiner 41₁Is
Be prepared. Also, make sure that each component is
Flow type switch 32₁In case of failure, the first embodiment
Similarly to the state, the optical space switch 6 with N inputs (N + 1) outputs
This can be dealt with by changing the setting of 1. Combined
Flow type switch 31₁After the malfunction of the repaired, the optical demultiplexer
21₁, Merge switch 31₁, Optical combiner 41_{N + 1}Is
Be prepared. Confluence type switch 31₁And optical combiner 41₁But
If both fail at the same time, change the settings of the above parts.
It can be dealt with by matching.

The present embodiment shows a configuration in which one spare set is provided for the working N sets. Similarly, the working N
To provide a spare H group for the group, the optical space switch 61
And (N + H) the number of output ports of the optical space switch 62 and the number of input ports of the optical space switch 62 and (N + H) M-type (N + H) output merging switches that replace the optical demultiplexer 21 and the merging type switch 32. Replaces the merger 41 (N
This is possible by providing (N + H) optical couplers with + H) inputs.

Also, the working N sets shown in FIGS. 3 and 4 and the spare 1
By setting one set as a unit and preparing this as an H unit, it is possible to correspond to a total of (N × H) input / output optical transmission lines. However, the number of output ports of the merging type switch 32 is ((N + 1) × H) and the number of input ports of the optical merging device 41 is ((N + 1) × H). In this case, the current (N
XH) becomes a spare H set.

(Third Embodiment) FIGS. 5 and 6 show a third embodiment of the wavelength division type optical communication path of the present invention. The feature of this embodiment is that the quality (bit error rate etc.) of a signal channel in a specific optical transmission line is changed by using the components provided as a backup system in the second embodiment shown in FIGS. 3 and 4. It is in the place where it can be measured. That is, instead of the optical space switches 61, 62, (N + 1) input (N +
1) The output optical space switches 63 ₁ and 63 ₂ are provided, and the signal characteristic measuring unit 100 is connected between the output port (N + 1) of the optical space switch 63 _{2 and} the input port (N + 1) of the optical space switch 63 _1. It is characterized by having done.

In this configuration, the operation when there is no failure and when there is a failure is the same as that of the second embodiment. Here, the case where the quality of the signal channel accommodated on the output optical transmission line 12 ₁ is measured when there is no failure in the component will be described with reference to FIG. Optical demultiplexer 21 _{N + 1} , merging type switch 32 _{N + 1} , optical merging device 41 _{N + 1}
Shall be prepared as a backup system.

The (N + 1) input (N + 1) output optical space switch 63 ₂ is set to output the signal light input from the input port 1 to the output port (N + 1). Thereby, the wavelength-multiplexed signal light output to the output optical transmission line 12 ₁ can be input to the signal characteristic measuring unit 100. The signal characteristic measuring unit 100 performs a predetermined measurement on the wavelength division multiplexed signal light, and outputs the wavelength division multiplexed signal light with the (N + 1) input (N + 1) output optical space switch 63 ₁
Input to the input port (N + 1). The optical space switch 63 ₁ is set to output the signal light input from the input port (N + 1) to the output port (N + 1).
The signal light is input to the merging type switch 32 _{N + 1} via the optical demultiplexer 21 _{N + 1} . The confluent switch 32 _{N + 1} is
All signal lights from input ports 1 to M are output ports (N +
Set to output from 1). Merge switch 32
_The signal light output from the N + 1 output port (N + 1) is
It is input to the input port (N + 1) of the optical space switch 63 ₂ via the optical combiner 41 _{N + 1} . Optical space switch 63 ₂
Sets the signal light input from the input port (N + 1) to the output port 1. As a result, the output optical transmission line 1 does not affect other signal channels.
It is possible to measure the quality of the signaling channel accommodated on 2 ₁ .

Next, the case where the quality of the signal channel accommodated on the input optical transmission line 11 ₁ is measured when there is no failure in the component parts will be described with reference to FIG. Optical demultiplexer 21 _{N + 1} , merging type switch 32 _{N + 1} , optical merging device 4
1 _{N + 1} shall be prepared as a backup system. Merging switch 32 ₁ which handles the signaling channel is accommodated on the input optical transmission lines 11 _1, input port 1
It is set so that all the signal lights of to M are output from the output port (N + 1). The signal light output from the output port (N + 1) of the merging type switch 32 ₁ is supplied to the optical combiner 41 _{N + 1.}
Is input to the input port (N + 1) of the (N + 1) input (N + 1) output optical space switch 63 ₂ . The optical space switch 63 ₂ is set to output the signal light input from the input port (N + 1) to the output port (N + 1). As a result, the wavelength division multiplexed signal light input from the input optical transmission line 11 ₁ can be input to the signal characteristic measuring unit 100.

The signal characteristic measuring section 100 performs a predetermined measurement on the WDM signal light and inputs the WDM signal light to the input port (N + 1) of the optical space switch 63 ₁ . The optical space switch 63 ₁ outputs the signal light input from the input port (N + 1) to the output port (N +
Set to output to 1). Optical space switch 63 ₁
The signal light output from the optical fiber is input to the merging type switch 32 _{N + 1} via the optical demultiplexer 21 _{N + 1} . Merge switch 3
2 _{N + 1} is set to be the same as the setting of the merging switch 32 ₁ before the measurement is started, and each signal light is sent to the optical combiner 41 _j corresponding to the same output optical transmission line 12 _j as before the measurement is started. It
The signal lights combined by the optical combiner 41 _j are output to the output optical transmission line 12 _j via the optical space switch 63 ₂ . As a result, the quality of the signal channel accommodated on the input optical transmission line 11 ₁ can be measured without affecting other signal channels.

With such a configuration, it is possible to identify a node in which quality deterioration has occurred, or to periodically or irregularly observe the characteristics of the signal channel at each node to detect time-dependent quality deterioration. It is possible to prevent the communication from being stopped. Although the third embodiment shown in FIGS. 5 and 6 shows the configuration in which one signal characteristic measuring unit 100 is provided for the number N of input / output optical transmission lines, a plurality of H signal characteristic measuring units are provided. It is also possible to provide. In this case, (N + H) M output optical demultiplexers 21 are provided, and (N + H) M input (N + H) output merging switches are provided instead of the M input (N + 1) output merging switches 32. , (N + 1) input optical combiner 41 is replaced by (N + H) input optical combiner (N +
H), and the number of input / output ports of the optical space switches 63 ₁ and 63 ₂ is changed to (N + H).

FIG. 7 shows a configuration example of the signal characteristic measuring section 100. As shown in (a), the signal characteristic measuring section 100 is composed of a detecting section 101 for inputting / outputting signal light and a measuring section 102 connected to the detecting section 101. Detection unit 101
Measures the information of the signal light by probing with light.
There is a configuration for transmitting the signal light to the measurement unit 102, a configuration for performing optical demultiplexing and optical insertion, and a configuration for branching a part of the signal light to the measurement unit 102 by using the optical branching circuit 103 as shown in (b). The measuring unit 102
The quality of each signal light is measured by including means for selecting or demultiplexing a part or all of the wavelength-multiplexed signal light to be measured. Further, when the measurement result shows that there is an error in the signal, the detection unit 101 may perform error correction on a part or all of the wavelength-multiplexed signal light. Further, the detection unit 101 may include an opto-electric converter and an electro-optical converter, and the electric signal may be sent to the measurement unit 102.

(Combination of the Second and Third Embodiments) In each of the embodiments shown in FIGS. 3 to 6, (N + 2) M output optical demultiplexers 21 are provided and M inputs (N + 1).
(N + 2) M input (N + 2) output merging switches are provided instead of the output merging switch 32, and (N + 2) input optical merging devices are (N + 2) instead of the (N + 1) input optical merging device 41. One set is provided for the current system, one set is for the standby system, and one set is for the signal characteristic measurement. Further, the number of input / output ports of the optical space switches 63 ₁ and 63 ₂ is changed to (N + 2). As a result, it is possible to measure the signal characteristics while providing the standby system. Similarly, a plurality of sets may be provided for each of the standby system and the signal characteristic measuring device.

(Fourth Embodiment) First Embodiment (Fig.
1, FIG. 2), the second embodiment (FIGS. 3, 4), and the third embodiment.
Embodiment (FIGS. 5 and 6), and the second embodiment and the third embodiment
In the combination of the embodiments, as shown in FIG.
The regenerative repeater circuit 14 is connected to each output line of the output optical demultiplexer 21. ₁~
14_MInsert. As a result, the input / output signal light
Amplification of signal light and waveform shaping when intensity is low
Other processing can be performed.

(Fifth Embodiment) First Embodiment (FIG.
1, FIG. 2), the second embodiment (FIGS. 3, 4), and the third embodiment.
Embodiment (FIGS. 5 and 6), and the second embodiment and the third embodiment
In the combination of the embodiments, as shown in FIG.
The wavelength conversion circuit 15 is connected to each output line of the output optical demultiplexer 21. ₁~
15_MInsert. This changes the wavelength of the input signal light.
It can be exchanged and connected.

[0041]

As described above, the wavelength division type optical communication path of the present invention can improve reliability against failure due to the redundant configuration which does not require switching back from the standby system to the working system at the time of failure recovery. . Further, with the configuration using the merging type switch, it is possible to flexibly cope with an increase or decrease in the number of input / output transmission lines by increasing or decreasing the components of the optical communication path. That is, it is possible to economically configure a wavelength division type optical communication path that is highly expandable with respect to fluctuations in traffic demand.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment (when there is no failure).

FIG. 2 is a block diagram showing the _first embodiment (when the merge-type switch 31 ₁ has a failure).

FIG. 3 is a block diagram showing a second embodiment (when there is no failure).

FIG. 4 is a block diagram showing a second embodiment (when the optical combiner 41 ₁ is out of order).

FIG. 5 is a block diagram showing a third embodiment (when measuring the quality of a signal channel on the output optical transmission line 12 ₁ ).

FIG. 6 is a block diagram showing a third embodiment (when measuring the quality of a signal channel on the input optical transmission line 11 ₁ ).

7 is a block diagram showing a configuration example of a signal characteristic measuring section 100. FIG.

FIG. 8 is a block diagram showing a fourth embodiment.

FIG. 9 is a block diagram showing a fifth embodiment.

FIG. 10 is a block diagram showing a configuration of a conventional wavelength division type optical communication path using an optical space switch.

FIG. 11 is a block diagram showing another configuration of a conventional wavelength division type optical communication path using an optical space switch.

12 is a block diagram showing a redundant configuration example of an optical space switch in the conventional wavelength division type optical communication path shown in FIG.

13 is a block diagram showing an example of a redundant configuration of an optical space switch in the conventional wavelength division type optical communication path shown in FIG.

[Explanation of symbols]

11 Input optical transmission line 12 output optical transmission line 14 Regenerative relay circuit 15 Wavelength conversion circuit 21 M output optical demultiplexer 31 M input N output merge switch 32 M input (N + 1) output merging type switch 41 (N + 1) input optical combiner 61 N input (N + 1) output optical space switch 62 (N + 1) input N output optical space switch 63 (N + 1) input (N + 1) output optical space switch 100 Signal characteristics measurement unit 101 detection unit 102 measuring unit 103 Optical branch circuit

Continuation of the front page (56) Reference JP-A-7-67153 (JP, A) JP-A-53-118907 (JP, A) JP-A-59-19497 (JP, A) Atsushi Watanabe, Satoshi Okamoto, High reliability Optical Path Cross-Connect System Configuration, Proc. Of the 1996 IEICE General Conference, Japan, The Institute of Electronics, Information and Communication Engineers, March 1996, Communications (2), B-1151, p. 583 Atsushi Watanabe, Satoshi Okamoto, Study on reliable N + 1 redundant OPXC system, Proceedings of the 1997 IEICE General Conference, Japan, The Institute of Electronics, Information and Communication Engineers, March 1997, Communications (2) Volume, B- 10-220, p. 729 (58) Fields investigated (Int.Cl. ⁷ , DB name) H04Q 3/52

Claims (5)

(57) [Claims] 1. A plurality of M channels of wavelength-division multiplexed signal light are respectively input from a plurality of N input optical transmission lines, the signal channels are switched, and N output optical transmissions are respectively performed as M-channel wavelength multiplexed signal lights. In the wavelength division type optical communication path that outputs to the optical path, the N input optical transmission paths are connected to the input ports and
Output the wavelength multiplexed signal light from the optical power transmission line to the (N + H) route .
N inputs that are assigned to N routes among the power ports
An (N + H) output optical space switch (where H is an integer of 1 or more), each connected to an output port of the optical space switch , and
(N + H) M outputs that input the signal light output from the optical space switch and demultiplex it into M channel signal lights.
Of the optical demultiplexers and the (N + H) optical demultiplexers , respectively,
(N + H) M-input / N-output converging type switches for allocating the M outputs of the device to N routes according to wavelengths, and the signal light for each route output from the (N + H) converging type switches. An optical combiner with N (N + H) inputs that combine and output to the N output optical transmission lines corresponding to each path is provided, and H optical demultiplexers are provided by switching the optical space switch. A wavelength division type optical communication path characterized by using a switch and H converging type switches as a standby system. 2. A plurality of M-channel wavelength-multiplexed signal lights are respectively input from a plurality of N optical input transmission lines, the signal channels are switched, and N output optical transmissions are respectively performed as M-channel wavelength-multiplexed signal lights. In the wavelength division type optical communication path that outputs to the optical path, the N input optical transmission paths are connected to the input ports and
Exiting the wavelength-multiplexed signal light from the force optical transmission line (N + H) route
N inputs that are assigned to N routes among the power ports
A (N + H) output first optical space switch (where H is an integer greater than or equal to 1), each connected to an output port of the first optical space switch.
And (N + H) M output optical demultiplexers for inputting the signal light output from the optical space switch and demultiplexing the signal lights into M channel signal lights, respectively, and the (N + H) optical demultiplexers. Each optical demultiplexer
(N + H) M inputs (N ) for allocating M outputs of the device to N routes among (N + H) routes according to wavelengths.
+ H) output merging switch and (N + H) (N + H) inputs that combine the signal light for each route output from the (N + H) merging switches.
Of the optical multiplexer and the (N + H) optical multiplexers to distribute the wavelength-division-multiplexed signal light output to the N output optical transmission paths corresponding to the respective routes (N + H) An optical space switch, the first optical space switch and the second light
A wavelength division type optical communication path characterized by using H optical demultiplexers, H merging type switches and H optical merging devices as a standby system by switching space switches . 3. The wavelength division type optical communication path according to claim 2, wherein instead of the first optical space switch, the signal light of (N + H) input ports is distributed to each of (N + H) output ports. A third optical space switch having (N + H) input (N + H) output is used, and the signal light of (N + H) input ports is replaced with (N + H) output ports instead of the second optical space switch. A fourth optical space switch having (N + H) input (N + H) output that is distributed to each of the three optical space switches is used, and H output ports of the fourth optical space switch and H output ports of the third optical space switch are used. 4th between input port
An input section for inputting the signal light output from the optical space switch, an output section for outputting the signal light as the signal light of the same format or a different format, and a measuring section for measuring the characteristics of the input signal light. A wavelength division type optical communication path characterized in that H signal characteristic measuring units having are connected. 4. In the wavelength division type optical communication path according to claim 1, amplification of signal light of each channel demultiplexed between an optical demultiplexer and a converging type switch. , A wavelength division type optical communication path having a configuration in which M regenerative repeating circuits for performing reshaping processing such as waveform shaping are inserted. 5. The wavelength of the signal light of each channel demultiplexed between the optical demultiplexer and the converging type switch in the wavelength division type optical communication path according to any one of claims 1 to 3. A wavelength division type optical communication path having a configuration in which M number of wavelength conversion circuits for converting the wavelengths are inserted.