JPH08256110A - Light wavelength multiplex transmission device - Google Patents

Abstract

PURPOSE: To confirm the routing normalcy of light wavelength in a light wavelength multiplex transmission network without interrupting the user signal. CONSTITUTION: A transmission means consists of a routing management part 31, an electro-optical conversion part 36, a routing information multiplexing part 32 and a light wavelength multiplexing part 33. Then the optical signal of the user signal multiplexed by the routing information R1 is transmitted to a light wavelength multiplex transmission network. A separation multiplex means consists of a light wavelength separation part 34, a photoelectric conversion part 37, a routing information separation part 38, a routing information multiplexing part 32 and a light wavelength multiplexing part 33. Then the routing information R2 of the passing tested light wavelength is separated and sent to the part 31, and this tested light wavelength is multiplexed by the information R1. Furthermore, the parts 34, 37 and 38 constructs a separation means against the terminating tested light wavelength. Thus the information R2 is separated and sent to the part 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical wavelength division multiplex transmission device for performing a routing normality test of each optical wavelength in an optical wavelength division multiplex transmission network without interruption of user signals.

[0002]

2. Description of the Related Art In an optical wavelength division multiplexing transmission network, a plurality of optical wavelengths are multiplexed on one optical fiber transmission line to transmit a user signal. At this time, the user signal is modulated with light having a wavelength of a limited frequency component and converted into an optical signal. At each node in the optical wavelength division multiplexing transmission network, each multiplexed optical signal is switched to a different path for each optical wavelength of the optical signal. That is, each node switches the path based on the optical wavelength of the input optical signal. The transmission of the optical signal by switching the path for each of the optical signals having different optical wavelengths is hereinafter referred to as "optical wavelength routing". FIG. 2 is a diagram showing an example of an optical wavelength division multiplexing transmission network. This optical wavelength multiplexing transmission network has six nodes N10 to N15, and each of the nodes N10 to N15 is provided with an optical wavelength multiplexing transmission device for transmitting and receiving a user signal by optical wavelength multiplexing. An optical fiber F connects between the nodes N10 to N15. In this optical wavelength division multiplexing transmission network, for example, the optical signal OP20 transmitted from the optical wavelength division multiplexing transmission device of the node N10 after the user signal is modulated at the optical wavelength λ1 is transmitted to the node N.
11 and the node N14, the optical wavelength is routed to the node N15 and terminated at the optical wavelength multiplex transmission device of the node N15. The optical signal OP21 transmitted from the node N10 after the user signal is modulated with the same optical wavelength λ1 as the optical signal OP20 passes through the node N13 and is terminated at the node N14. On the other hand, the optical signals OP20 and OP
The optical signal OP22 transmitted from the node N10 after the user signal is modulated with the optical wavelength λ2 different from that of the node 21 is
The optical wavelength is routed to the node N12 via 11 and further terminated at the node N15 via the node N12.

Conventionally, in such an optical wavelength multiplex transmission network, when confirming the normality of the routing of the optical wavelength of each optical wavelength, the transmission of the user signal is stopped and a test pattern having the same optical wavelength as the user signal is sent. I went there. For example, when checking the path of the optical signal OP22, first, the optical signal O
The user signal using the optical wavelength of P22 is switched to the optical signal OP20 of another optical wavelength, or the user signal is stopped so that the test pattern can flow. In this state, the test pattern is flown, and each passing node N11, N
At 12, an optical wavelength under test of a plurality of multiplexed optical wavelengths is branched by the optical wavelength multiplexing transmission device. One of the branched optical wavelengths under test passes through the nodes N11 and N12, and the other is received by the nodes N11 and N12 and demodulated into electric signals. As a result, it is confirmed that the test pattern passes through the nodes N11 and N12. On the other hand, during transmission of a user signal, it is possible to confirm that the optical wavelength is passing through the node by branching the optical signal at the transit node and converting the optical wavelength of the one that does not pass into the electrical signal. . However, the normality of optical wavelength routing could not be confirmed. For example, the route of the optical signal OP20 originally transmitted at the same optical wavelength λ1 is node N10 → N11 → N14 → N15, and the route of the optical signal OP21 is node N10 → N13 → N14. However, when transmitting the user signal, the nodes N10 and N
14 may perform routing of an abnormal optical wavelength due to a failure or the like. FIG. 3 is a diagram showing an example of incorrect optical wavelength routing with respect to FIG. In FIG. 3, the route of the optical signal OP20 is node N10 → N13 → N14 → N.
15 and the route of the optical signal OP21 is node N10 → N
11 → N14. In this case, even if it is attempted to confirm the normality of the routing of the optical wavelength without interruption of the user signal, it can be confirmed that the optical wavelength of λ1 passes through each of the nodes N11 and N13. It is not possible to confirm whether the signal is OP20 or OP21.

[0004]

The conventional optical wavelength multiplex transmission device has the following problems. Even when the normality of the routing of the optical wavelength was checked while the user signal was being transmitted, it was not possible to confirm through which node the optical wavelength reached the target node. That is, it can be confirmed that the optical wavelength of λ1 passes through each of the nodes N11 and N13 in FIG. 3, but it is not possible to determine whether the optical wavelength is the optical signal OP20 or the optical signal OP21. , Node N15
It was not possible to confirm whether the optical signal terminated with the optical signal OP20 or the optical signal OP21. If I tried to check the route, I had to interrupt the user signal.

[0005]

In order to solve the above-mentioned problems, a first invention is an optical wavelength division multiplex transmission apparatus which is installed in each node of an optical wavelength division multiplexing transmission network and which transmits and receives a user signal by optical wavelength division multiplexing. , The following measures are taken. That is, the optical wavelength division multiplexing transmission apparatus generates routing information for detecting a routing path of an optical wavelength when transmitting the user signal, modulates the user signal into an optical signal, and then frequency band of the user signal. And a transmission means for multiplexing the routing information into the user signal, which has become an optical signal, in a frequency band different from that for transmitting to the optical wavelength division multiplexing transmission network. In addition, the optical wavelength division multiplexing transmission device branches the optical wavelength under test that passes through the node, converts one of the branched optical wavelengths under test into an electrical signal, and then routes the electrical signal. The information is separated, the route of the optical wavelength under test is confirmed from the routing information, the frequency band used for the optical wavelength under test is confirmed, and the information is sent to the routing management unit that generates the routing information of the own node. Demultiplexing and multiplexing means for modulating the other branched optical wavelength under test, multiplexing the routing information of the own node in a frequency band different from the frequency band of the optical wavelength under test, and transmitting the multiplexed information to the optical WDM transmission network. Is equipped with. Further, the optical wavelength multiplexing transmission device is provided with a separating means for demodulating the optical wavelength under test to be terminated into an electric signal and then separating the routing information from the electric signal and sending the separated routing information to the routing management unit.

[0006]

According to the first aspect of the invention, since the optical wavelength division multiplex transmission device is configured as described above, the transmitting means generates the user signal and transmits the optical wavelength in a frequency band different from the frequency band of the user signal. The routing information is multiplexed and transmitted. The demultiplexing / multiplexing unit separates the routing information from the optical wavelength under test passing through the node and sends the routing information to the routing management unit, and outputs the optical wavelength under test in a frequency band different from the frequency band of the optical wavelength under test passing through the node. Routing information is added and multiplexed and sent. The separating means separates the routing information from the terminating optical wavelength under test and sends it to the routing management unit. Therefore, the route of the optical wavelength routing in the optical wavelength multiplexing transmission network is confirmed without interrupting the user signal. Therefore, the above problem can be solved.

[0007]

1 is a functional block diagram of an optical wavelength division multiplexing transmission apparatus showing an embodiment of the present invention. The optical wavelength division multiplexing transmission device is installed in each node of the optical wavelength division multiplexing transmission network to transmit and receive user signals by optical wavelength division multiplexing, and includes a routing management unit 31. The routing management unit 31 has a function of communicating with a network management center that manages the entire routing of the optical wavelength multiplexing transmission network, and transmits from the installed own node in order to detect the route of the optical wavelength routing. Has a function of generating the routing information R1 to be read, a function of reading the input routing information R2 and confirming the routing path of the optical wavelength, a function of instructing the optical wavelength of the signal transmitted from the own node, and the like. . The routing information R1 from the routing management unit 31 is supplied to the routing information multiplexing unit 32. The routing information multiplexer 32 receives the optical signal OPR passing through the node or the source node (that is,
First, an optical signal of a user signal S1 transmitted from a node that first generates an optical signal from an electric signal is modulated with a subcarrier frequency by an internal optical intensity modulator (not shown) so that the frequency bands do not overlap. It has a function to multiplex. The output signal S32 of the routing information multiplexer 32 is input to the optical wavelength multiplexer 33. Further, this optical wavelength division multiplexing transmission device is provided with an optical wavelength demultiplexing unit 34 for inputting an optical signal transmitted by wavelength division multiplexing in an optical fiber and transmitting it, and demultiplexing the optical signal for each optical wavelength. The output is connected to the optical space switch section 35. The electro-optical conversion unit 36 has a function of converting the user signal S1 transmitted from its own node from an electric signal to an optical signal. The output side of the electro-optical conversion unit 36 is connected to the optical space switch unit 35. Optical space switch unit 35
The output side of is divided into two routes. That is, one output side of the optical space switch section 35 is connected to the photoelectric conversion section 37, and the other output side is connected to the routing information multiplexing section 32. The routing information separating section 38 responds to the output signal EIR of the photoelectric conversion section 37 by routing information R
It has a function of separating the two and transmitting the separated routing information R2 to the routing information demodulation unit 39.
The routing information demodulation unit 39 demodulates the routing information R2 modulated by the subcarriers to the baseband,
It has a function of sending to the routing management unit 31.

FIGS. 4A, 4B and 4C are diagrams for explaining the operation of the optical space switch section in FIG. The optical space switch unit 35 has a function of switching the output to the optical space under the control of the routing management unit 31. For example, when transmitting a user signal, the optical space switch unit 35 converts the signal from the electro-optical conversion unit 36 into a signal shown in FIG.
As shown in FIG. 4B, for the wavelength of the light under test that is supplied to the routing information multiplexer 32 as shown in FIG. It has a function of branching a wavelength and transmitting it to the photoelectric conversion unit 37 and the routing information multiplexing unit 32. When the optical wavelength obtained through the optical wavelength demultiplexing unit 34 is terminated at its own node, the optical space switch unit 35 transmits the output signal to the photoelectric conversion unit 37 as shown in (c) of FIG. It has a function to do. As a result, the routing management unit 31, the electro-optical conversion unit 36, the routing information multiplexing unit 32, and the optical wavelength multiplexing unit 33 constitute a sending unit, which sends the optical signal of the user signal multiplexed with the routing information. It has the function of sending to the wavelength division multiplexing transmission network. In addition, the optical wavelength demultiplexing unit 34, the photoelectric conversion unit 37, the routing information demultiplexing unit 3
8, routing information multiplexer 32, and optical wavelength multiplexer 3
3, the demultiplexing / multiplexing means is constituted, and the demultiplexing / multiplexing means has a function of separating the routing information of the wavelengths of the light under test to be transmitted to the routing management unit 31 and multiplexing the routing information to the wavelengths of the light under test to be passed. Have Further, the optical wavelength demultiplexing unit 34, the photoelectric conversion unit 37, and the routing information demultiplexing unit 38 constitute demultiplexing means for the optical wavelengths, and the demultiplexing means demultiplexes the routing information and sends it to the routing management section 31. have. Next, the operation of the optical wavelength multiplex transmission device of FIG. 1 in the normality test of the optical wavelength routing will be described. The node that transmits the optical signal OPS of the user signal S1 in which the routing information R1 is multiplexed is a node Ni, the node that transmits the optical signal OPS in which the routing information R1 is multiplexed to the received optical signal OPR is a node Nj, and the received optical signal OPR is A node that terminates is defined as a node Nk. FIG. 5 is a diagram illustrating multiplexing of a user signal to be transmitted and routing information. This figure and Figure 1
The operation of the optical wavelength division multiplexing transmission apparatus of FIG. 1 at the node Ni will be described with reference to FIG.

In the optical WDM transmission apparatus of FIG. 1 in the node Ni, the routing information R1 including the address of the node Ni generated by the routing management unit 31 is multiplexed by the routing information multiplexing unit 32 into the user signal S1.
The user signal S1 becomes an optical signal modulated into an optical wavelength based on the instruction of the routing management unit 31 by the electro-optical conversion unit 36, and is transferred to the routing information multiplexing unit 32. The routing information multiplexing unit 32 multiplexes the user information S1 of the optical signal and the routing information R1 as shown in FIG. That is, the user signal S1 of the optical signal is modulated using the subcarrier frequency, and the routing information R1 is placed in a frequency band different from the frequency band of the user signal S1.
Are multiplexed. Routing information R1 and user signal S1
The optical signal OPS in which is multiplexed is output to the optical wavelength multiplexer 33. The optical wavelength multiplexing unit 33 multiplexes the optical signal OPS to the optical wavelength multiplexing transmission network and sends it. FIG. 6 is a diagram for explaining multiplexing / separation of passing user signals and routing information. The operation of the optical WDM transmission apparatus of FIG. 1 in the node Nj will be described with reference to this figure and FIG.

The optical wavelength demultiplexing unit 34 in the optical wavelength multiplexing transmission device of FIG. 1 installed in the node Nj demultiplexes the input optical wavelength group transmitted by optical wavelength multiplexing in the optical fiber F for each optical wavelength. The optical wavelength under test OPR in the input optical wavelength group is branched by the optical space switch section 35 and transferred to the photoelectric conversion section 37 and the routing information multiplexing section 32. The opto-electric conversion unit 37 demodulates the optical wavelength under test OPR into an electric signal to obtain an electric signal ElR. The optical wavelength under test ElR demodulated into this electric signal is sent to the routing information separating unit 38. The routing information separating section 38 separates the user information S2 and the routing information R2 from the optical wavelength under test ElR converted into an electric signal by using an electric filter as shown in FIG. The separated routing information R2 is sent to the routing information demodulation unit 39. The routing information demodulation unit 39 demodulates the routing information R2 modulated by the subcarriers to the baseband, and the routing management unit 3
Send to 1. The routing management unit 31 reads the routing information R2, confirms the transmitting node and the passing node of the optical signal under test OPR, further confirms the frequency band used of the optical signal under test OPR, and includes the address of the node under test including the address of its own node. A band in which the routing information R1 of the optical wavelength can be newly multiplexed is determined. The routing information R1 generated by the routing management unit 31 is multiplexed by the routing information multiplexing unit 32 with the optical signal under test OPR passing through the own node. Multiplexing of the optical signal under test OPR and the routing information R1 in the routing information multiplexer 32 is performed as shown in FIG. That is, the optical signal under test OP using the subcarrier frequency
R is modulated, and the routing information R1 is multiplexed in a frequency band different from the frequency band of the optical signal under test OPR. The optical signal OPS in which the routing information R1 and the optical signal under test OPR are multiplexed is output to the optical wavelength multiplexer 33. The optical wavelength multiplexing unit 33 multiplexes the optical signal OPS to the optical wavelength multiplexing transmission network and sends it out.

FIG. 7 is a diagram for explaining multiplexing / demultiplexing of a terminating user signal and routing information. This figure and Figure 1
The operation of the optical wavelength division multiplexing transmission apparatus in FIG. 1 in the node Nk will be described with reference to FIG. The optical wavelength demultiplexing unit 34 in the optical wavelength multiplexing transmission device of FIG. 1 installed in the node Nk is
The input optical wavelength group transmitted by being wavelength-multiplexed in the optical fiber F is separated for each optical wavelength. The optical wavelength under test OPR in the input optical wavelength group is transferred to the photoelectric conversion unit 37 by the optical space switch unit 35. The opto-electric converter 37 demodulates the optical wavelength under test OPR into an electric signal ElR. The optical wavelength under test ElR demodulated into this electric signal is the routing information separating unit 3
Sent to 8. The routing information separating unit 38 separates the optical wavelength under test ElR converted into an electric signal into user information S2 and routing information R2 by using an electric filter as shown in FIG. The separated routing information R2 is sent to the routing information demodulation unit 39. The routing information demodulation unit 39 demodulates the routing information R2 modulated by the subcarriers into a baseband and sends it to the routing management unit 31. Routing management unit 3
1 reads the routing information R2 and confirms the transmission node and passage node of the optical wavelength under test.

The above test results are transmitted from the routing management unit 31 of the node Nk to the network management center to confirm the normality of the optical wavelength routing. As described above, in the present embodiment, the node Ni multiplexes the routing information R1 on the user signal S1 and sends it out to the optical wavelength division multiplexing transmission network, and the node Nj additionally adds the routing information R1 and multiplexes it at the node Nk. The routing information R2 included in the optical wavelength from the optical wavelength multiplexing transmission network is separated, and the routing management unit 31 confirms the route of the optical wavelength routing.
Therefore, the normality of optical wavelength routing is collectively confirmed without interrupting the user signals S1 and S2.
The present invention is not limited to the above embodiment, and various modifications can be made. For example, routing information R1 and R2 prepared for confirming the normality of optical wavelength routing
Can be multiplexed with the user signal S1 not only when performing a test but also during normal operation. That is, normally, the node Ni multiplexes the routing information R1 and R2 with the user signal S1, the transit node Nj multiplexes additional routing information with these multiplexed signals, and the routing management unit 30 monitors this. If this is done, it becomes possible to easily detect the occurrence of a failure in each node, optical fiber, or the like.

[0013]

As described in detail above, according to the first invention, a user signal is generated in an optical wavelength division multiplexing transmission device, and an optical wavelength is routed to a frequency band different from the frequency band of the user signal. A transmission means for multiplexing and transmitting information, and a frequency band different from the frequency band of the optical wavelength under test which transmits routing information by separating the routing information from the optical wavelength under test passing through the node Since there is provided demultiplexing means for adding the routing information of the optical wavelength under test and transmitting the multiplexed information, and demultiplexing means for separating the routing information from the optical wavelength under test and transmitting it to the routing management unit, The route of the optical wavelength routing in the optical wavelength multiplexing transmission network can be confirmed without interrupting the signal, and the reliability of the optical wavelength multiplexing transmission network can be improved. According to the second invention, the routing management unit collectively collects the confirmation result of the route of the routing of the optical wavelength under test in the optical wavelength multiplexing transmission network obtained from the multiplexed routing information of the first invention. Since it has a function of notifying the network management center that manages the multiplex transmission network, the network management center can confirm the route of the optical wavelength routing in a short time.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an optical wavelength division multiplexing transmission apparatus showing an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an optical wavelength division multiplexing transmission network.

FIG. 3 is a diagram showing erroneous optical wavelength routing for FIG. 2.

FIG. 4 is a diagram for explaining the operation of the optical space switch section in FIG.

FIG. 5 is a diagram illustrating multiplexing of a user signal to be transmitted and routing information.

FIG. 6 is a diagram illustrating multiplexing / demultiplexing of a passing user signal and routing information.

FIG. 7 is a diagram illustrating multiplexing / demultiplexing of a terminating user signal and routing information.

[Explanation of symbols]

31 routing management unit 32 routing information multiplexing unit 33 optical wavelength multiplexing unit 34 optical wavelength demultiplexing unit 35 optical space switch unit 36 electro-optical conversion unit 37 photoelectric conversion unit 38 routing information demultiplexing unit 39 routing information demodulation unit S1, S2 user information OPS , OPR Optical signal R1, R2 Routing information

Claims (2)

[Claims] 1. An optical wavelength division multiplex transmission apparatus installed in each node of an optical wavelength division multiplex transmission network for transmitting and receiving a user signal by optical wavelength division multiplexing, for detecting an optical wavelength routing path when transmitting the user signal. Of the routing information is generated, the user signal is modulated into an optical signal, and then the routing information is multiplexed with the user signal that has become an optical signal in a frequency band different from the frequency band of the user signal. A sending means for sending to the network, and a branch is performed for the optical wavelength under test that passes through the node, and one of the optical wavelengths under test that has been branched is converted into an electrical signal, and then the routing information is obtained from the electrical signal. The route is separated and the route of the optical wavelength under test is confirmed from the routing information and the frequency band used for the optical wavelength under test is confirmed to determine the route of the own node. To the routing management unit that generates the ringing information, and modulates the other branched optical wavelength under test to multiplex the routing information of the local node into a frequency band different from the frequency band of the optical wavelength under test. Demultiplexing means for sending to the optical wavelength division multiplexing transmission network, and demultiplexing means for demodulating the optical wavelength under test to be terminated into an electric signal and then separating the routing information from the electric signal and sending it to the routing management section, An optical wavelength division multiplex transmission device characterized by being provided. 2. The routing management unit collectively confirms the result of confirmation of the route of the optical wavelength under test routing in the optical wavelength division multiplexing transmission network obtained from the multiplexed routing information. The optical wavelength division multiplex transmission device according to claim 1, having a function of notifying to a network management center for management.