Optical communication system, management control device, and control signal transmission method

Abstract

This optical communication system comprises: a management / control device that manages communication between at least one first subscriber device and at least one second subscriber device provided at a position facing the first subscriber device. The management / control device comprises: a control signal generation unit that generates a control signal used for control and management for transmission to the first subscriber device; and an optical communication unit that converts the control signal, which has been generated by the control signal generation unit, into an optical signal having a different wavelength that of a main signal transmitted by the second subscriber device which communicates with the first subscriber device, and that transmits the optical signal. The management / control device also comprises an optical multiplexing unit that is provided on a communication path between the first subscriber device and the second subscriber device, and that multiplexes the main signal transmitted by the second subscriber device and the optical signal transmitted from the optical transmission unit.　

Description

[Technical Field]

[0001] The present invention relates to an optical communication system, a management control device, and a control signal transmission method. [Background technology]

[0002] In a conventional optical communication system, a subscriber device needs to open an optical path to connect to a subscriber device with which it will communicate in order to perform communication. Figures 7 and 8 are diagrams for explaining a method for opening an optical path in a conventional optical communication system 100. As shown in Figure 7, the conventional optical communication system 100 includes a plurality of subscriber devices 200-1 to 200-3, a plurality of subscriber devices 300-1 to 300-3, a plurality of control units 400-1 to 400-2, and a plurality of optical SWs 500-1 to 500-2.

[0003] The subscriber devices 200-1 to 200-3 are connected to an optical SW 500-1 via an optical transmission line, and the subscriber devices 300-1 to 300-3 are connected to an optical SW 500-2 via an optical transmission line. The optical SW 500-1 and the optical SW 500-2 are connected via an optical communication NW 600 configured by an optical transmission line. The control unit 400-1 manages the subscriber device 200 and controls the operation of the optical SW 500-1. The control unit 400-2 manages the subscriber device 300 and controls the operation of the optical SW 500-2.

[0004] Assume now that the optical switch 200-1 is newly connected to the optical SW 500-1. When the optical switch 200-1 is initially connected, the optical switch control unit 410 sets up a connection between the ports of the optical SW 500-1 so that the optical switch 200-1 communicates with the optical switch management and control unit 420. This allows the optical switch 200-1 and the optical switch management and control unit 420 to exchange information necessary for registering and authenticating the optical switch 200-1, and allows the optical switch management and control unit 420 to instruct the optical switch 200-1 on the emission wavelength. In this way, a control signal called an Auxiliary Management and Control Channel (AMCC) is used as a signal for managing and controlling the optical switches. The AMCC signal includes status information indicating, for example, the transmission and reception wavelengths, transmission optical intensity, and temperature of the optical transceiver.

[0005] When the registration and authentication of the subscriber device 200-1 and the wavelength setting are completed, the optical SW control unit 410 changes the setting of the inter-port connection of the optical SW 500-1 so that the optical signal transmitted from the subscriber device 200-1 is forwarded to the subscriber device 300-1, which is the communication partner. Similarly, the control unit 400-2 changes the setting of the inter-port connection of the optical SW 500-2 so that the optical signal transmitted from the subscriber device 200-1 is forwarded to the subscriber device 300-1, which is the communication partner. This makes it possible to open an optical path that directly connects the subscriber devices 200-1 and 300-1, as shown in FIG. 8.

[0006] However, in the configuration of the conventional optical communication system 100, once an optical path is opened, there is no control channel for transmitting a control signal from the control unit 400-1 or 400-2 to the subscriber device. Therefore, conventionally, as shown in Figure 9, a control signal superimposing unit is provided in the optical transmission path, and the control signal from the control unit is superimposed as AMCC on the optical signal output from the subscriber device 200 to the subscriber device 300, thereby making it possible to transmit a control signal from the control unit to a subscriber device for which an optical path has already been opened.

[0007] 9 is a diagram showing a configuration in which a control signal superimposing unit is provided in a conventional optical communication system 100. As shown in FIG. 9, the optical communication system 100a includes multiple subscriber units 200-1 to 200-3, multiple subscriber units 300-1 to 300-3, multiple control units 400a-1 to 400a-2, multiple optical switches 500-1 to 500-2, multiple optical branching units 650-1 to 650-3, and multiple control signal superimposing units 660-1 to 660-3. The optical branching units 650-1 to 650-3 are provided on each optical transmission line and branch optical signals transmitted from the subscriber units 200-1 to 200-3. The optical signals branched by the optical branching units 650-1 to 650-3 are output to the control signal receiving unit 430 of the control unit 400a-1 and the control signal superimposing units 660-1 to 660-3.

[0008] The control signal receiving unit 430 acquires control signals from the optical signals branched by the optical branching units 650-1 to 650-3. The control signal superimposing units 660-1 to 660-3 superimpose the control signals transmitted from the control unit 400a-2 onto the optical signals branched by the optical branching units 650-1 to 650-3. The optical signals on which the control signals have been superimposed by the control signal superimposing units 660-1 to 660-3 are transmitted to the subscriber device 300 via the optical SW 500-2. [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] Takuya Kanai, Kazuaki Honda, Yasunari Tanaka, Makoto Kaneko, Kazutaka Hara, Junichi Kani, and Tomoaki Yoshida, "Photonic Gateway Supporting All-Photonics Network," IEICE General Conference, B-8-20, March 2021. Summary of the Invention [Problem to be solved by the invention]

[0010] 9, however, the control signal from the control unit 400a-2 to the subscriber device 300 needs to be superimposed on the optical signal transmitted from the subscriber device 200, which is the counterpart device of the subscriber device 300. Therefore, if the optical signal transmitted from the subscriber device 200 does not reach the control signal superimposing units 660-1 to 660-3, the control signal cannot be transmitted. For example, if a transmitter failure occurs in the subscriber device 200, a break in the optical transmission line occurs, or a port connection error or malfunction occurs in the optical SW 500-1 along the path, the optical signal transmitted from the subscriber device 200 will not reach the control signal superimposing units 660-1 to 660-3. In such cases, there is a problem in that the control signal cannot be transmitted to the subscriber device.

[0011] In view of the above circumstances, the present invention aims to provide a technology that can transmit a control signal to a subscriber device even when an optical signal transmitted from the subscriber device does not reach the opposing subscriber device. [Means for solving the problem]

[0012] One aspect of the present invention is an optical communication system comprising: one or more first subscriber devices; and a management control device that manages communication between the first subscriber devices and one or more second subscriber devices located opposite the first subscriber devices. The management control device comprises: a control signal generating unit that generates a control signal used for management and control to be transmitted to the first subscriber device; an optical transmitting unit that converts the control signal generated by the control signal generating unit into an optical signal of a wavelength different from the wavelength of a main signal transmitted by a second subscriber device that communicates with the first subscriber device, and transmits the optical signal; and an optical multiplexing unit that is located on the communication path between the first subscriber device and the second subscriber device and multiplexes the main signal transmitted by the second subscriber device with the optical signal transmitted from the optical transmitting unit.

[0013] One aspect of the present invention is a management control device that manages communications between one or more first subscriber devices and one or more second subscriber devices located opposite the first subscriber devices, and includes: a control signal generating unit that generates a control signal used for management and control to be transmitted to the first subscriber device; and an optical transmitting unit that converts the control signal generated by the control signal generating unit into an optical signal of a wavelength different from the wavelength of a main signal transmitted by a second subscriber device that communicates with the first subscriber device, and transmits the optical signal to an optical multiplexing unit that is located on the communication path between the first subscriber device and the second subscriber device and multiplexes the main signal transmitted by the second subscriber device with another optical signal.

[0014] One aspect of the present invention is a control signal transmission method in an optical communication system including a management control device that manages communication between one or more first subscriber devices and one or more second subscriber devices located opposite the first subscriber devices, wherein the management control device generates a control signal used for management and control to be transmitted to the first subscriber device, converts the generated control signal into an optical signal of a wavelength different from the wavelength of a main signal transmitted by a second subscriber device that communicates with the first subscriber device, and transmits the optical signal, and an optical multiplexing unit is provided on the communication path between the first subscriber device and the second subscriber device, and multiplexes the main signal transmitted by the second subscriber device with the optical signal transmitted from the management control device. [Effects of the Invention]

[0015] According to the present invention, even if an optical signal transmitted from a subscriber unit does not reach the opposite subscriber unit, it is possible to transmit a control signal to the subscriber unit. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram illustrating an example of the configuration of an optical communication system according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating a configuration of a subscriber device in the first embodiment. [Figure 3] FIG. 3 is a sequence diagram showing a processing flow of the optical communication system according to the first embodiment. [Figure 4] FIG. 4 is a diagram showing another configuration of a subscriber device in the first embodiment. [Figure 5] FIG. 10 is a diagram illustrating an example of the configuration of an optical communication system according to a second embodiment. [Figure 6] FIG. 10 is a diagram illustrating an example of the configuration of an optical communication system according to a third embodiment. [Figure 7] FIG. 1 is a diagram for explaining a method for opening an optical path in a conventional optical communication system. [Figure 8] FIG. 1 is a diagram for explaining a method for opening an optical path in a conventional optical communication system. [Figure 9] FIG. 1 is a diagram showing a configuration in which a control signal superimposing unit is provided in a conventional optical communication system. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (First embodiment) Fig. 1 is a diagram showing an example of the configuration of an optical communication system 1 in the first embodiment. The optical communication system 1 includes a subscriber device 10, a subscriber device 20, a management control device 30, and an optical multiplexing unit 40. Although Fig. 1 shows a configuration in which the optical communication system 1 includes one subscriber device 10 and one subscriber device 20, a plurality of subscriber devices 10 and one subscriber device 20 may be included.

[0018] 1, a subscriber device 10 and a subscriber device 20 are connected via an optical transmission path 45. The optical transmission path 45 is, for example, an optical fiber. In the first embodiment, a configuration in which an optical signal is transmitted from the subscriber device 10 to the subscriber device 20 will be described.

[0019] The subscriber device 10 converts the main signal into an optical signal of wavelength λs (s is an integer equal to or greater than 1) and transmits it to the optical transmission line 45. Specifically, the subscriber device 10 converts the main signal into an optical signal of wavelength λs, which is the wavelength instructed by the management control device 30, and transmits it to the optical transmission line 45.

[0020] The subscriber device 20 is a device that communicates with the subscriber device 10. The subscriber device 20 receives the optical signal output from the optical multiplexing unit 40. The optical signal received by the subscriber device 20 is the optical signal multiplexed by the optical multiplexing unit 40. The subscriber device 20 may, for example, separate the received optical signal into a main signal and a control signal having different wavelengths, and then detect and demodulate the main signal and the control signal to receive the main signal and the control signal. If the control signal is an AMCC signal whose frequency band does not overlap with that of the main signal, the subscriber device 20 may, for example, detect the received optical signal, convert it into an electrical signal, branch it into the main signal and the control signal, and demodulate each of the branched electrical signals to receive the main signal and the AMCC signal.

[0021] The management control device 30 controls the subscriber devices 10 and 20, monitors control signals, and performs control based on the control signals. Here, controlling the subscriber devices 10 and 20 includes, for example, issuing instructions to the subscriber devices 10 and 20 to stop optical transmission, to change wavelengths, etc. The management control device 30 includes an optical transmitter 31 and a control signal generator 32. The optical transmitter 31 is composed of a control signal transmitter 33. The optical transmitter 31 and the optical multiplexer 40 are connected via an optical transmission path.

[0022] The control signal generator 32 generates a control signal for a destination to be controlled (in the first embodiment, the subscriber device 20). The control signal generated by the control signal generator 32 includes information such as "communication termination notification to the destination device (instruction to stop light emission)", "wavelength change due to destination switching or route switching", and "response to request to the subscriber device". The AMCC signal is an example of a control signal.

[0023] The control signal transmitter 33 converts the control signal generated by the control signal generator 32 into an optical signal having a wavelength (for example, wavelength λc) different from the wavelength λs of the optical signal (main signal) transmitted by the subscriber device 10. The control signal transmitter 33 transmits the converted optical signal to the optical multiplexer 40. For example, the control signal transmitter 33 identifies the wavelength of the optical signal transmitted by the subscriber device 10 based on information about the wavelength used by the subscriber device 10 stored in a memory (not shown).

[0024] The optical multiplexer 40 receives an optical signal with wavelength λs transmitted by the subscriber device 10 and an optical signal with wavelength λc transmitted by the control signal transmitter 33. The optical multiplexer 40 multiplexes the input optical signal with wavelength λs and the optical signal with wavelength λc. The optical multiplexer 40 outputs the multiplexed optical signal to the subscriber device 20 via the optical transmission path 45. If an optical signal from the subscriber device 10 is not input to the optical multiplexer 40, the optical multiplexer 40 outputs only the optical signal with wavelength λc transmitted by the control signal transmitter 33 to the subscriber device 20 via the optical transmission path 45. The optical multiplexer 40 may be an optical multiplexing means without wavelength selectivity (e.g., an optical coupler) or a wavelength multiplexing means with wavelength selectivity (e.g., a wavelength filter).

[0025] FIG. 2 is a diagram showing the configuration of the subscriber device 20 in the first embodiment. FIG. 2 shows the configuration of an optical receiving unit that receives an optical signal in the subscriber device 20. The subscriber device 20 includes an optical receiving unit 21. The optical receiving unit 21 is made up of a wavelength demultiplexing unit 22, PD23-1, and PD23-2. The wavelength demultiplexing unit 22 demultiplexes the input optical signal according to wavelength. PD23-1 and PD23-2 are connected to the wavelength demultiplexing unit 22. For example, an optical signal with a wavelength λs is output to PD23-1, and an optical signal with a wavelength λc is output to PD23-2.

[0026] PD23-1 converts the input optical signal with wavelength λs into an electrical signal, thereby enabling the subscriber device 20 to acquire the main signal. PD23-2 converts the input optical signal with wavelength λc into an electrical signal, thereby enabling the subscriber device 20 to acquire the control signal. PD23-1 and 23-2 are examples of receiving units. The configuration shown in FIG. 2 is a configuration for direct detection using a photodiode, but a similar configuration can also be used when coherent reception is applied. Note that when the subscriber device 20 has the configuration shown in FIG. 2, the frequency band of the control signal may be different from or overlap with that of the main signal.

[0027] FIG. 3 is a sequence diagram showing the flow of processing in the optical communication system 1 in the first embodiment. The subscriber device 10 transmits an optical signal with wavelength λs to the optical transmission line 45 (step S101). The optical signal with wavelength λs transmitted from the subscriber device 10 is input to the optical multiplexer 40 via the optical transmission line 45.

[0028] The control signal generating unit 32 of the management control device 30 generates a control signal to be transmitted to the subscriber device 20 (step S102). The control signal generating unit 32 outputs the generated control signal to the control signal transmitting unit 33. The control signal transmitting unit 33 converts the control signal output from the control signal generating unit 32 into an optical signal with a wavelength λc, which is different from the wavelength λs of the optical signal transmitted by the subscriber device 10. The control signal transmitting unit 33 transmits the converted optical signal with the wavelength λc to the optical multiplexing unit 40 (step S103).

[0029] The optical multiplexer 40 receives an optical signal with wavelength λs transmitted by the subscriber device 10 and an optical signal with wavelength λc transmitted by the control signal transmitter 33. The optical multiplexer 40 multiplexes the input optical signal with wavelength λs with the optical signal with wavelength λc (step S104). The optical signal multiplexed by the optical multiplexer 40 is input to the subscriber device 20 via the optical transmission path 45. The wavelength separator 22 of the subscriber device 20 wavelength-separates the input optical signal (step S105). For example, the wavelength separator 22 demultiplexes the input optical signal into an optical signal with wavelength λs and an optical signal with wavelength λc.

[0030] The PD 23-1 converts into an electric signal the optical signal with wavelength λs demultiplexed by the wavelength demultiplexer 22. The PD 23-2 converts into an electric signal the optical signal with wavelength λc demultiplexed by the wavelength demultiplexer 22 (step S106).

[0031] In the optical communication system 1 configured as described above, the management and control device 30 converts the control signal into an optical signal of a wavelength different from that of the optical signal transmitted from the subscriber device 10, and the optical multiplexing unit 40 multiplexes the control signal with the optical signal transmitted from the subscriber device 10. When the optical signal transmitted from the subscriber device 10 is input, the optical multiplexing unit 40 multiplexes the input optical signal with an optical signal of the different wavelength and outputs the multiplexed signal to the subscriber device 20. On the other hand, when the optical signal transmitted from the subscriber device 10 is not input, the optical multiplexing unit 40 outputs only the optical signal of the control signal transmitted from the management and control device 30 to the subscriber device 20. In this way, in the optical communication system 1, even when the optical signal transmitted from the subscriber device 10 does not reach the opposite subscriber device 20, it is possible to transmit the control signal to the subscriber device 20.

[0032] Furthermore, in the optical communication system 1, it is not necessary to provide an in-line control signal superimposing unit for each subscriber device that is the destination of a control signal in order to transmit the control signal, as in the conventional system. In addition, in the optical communication system 1, with a simple configuration in which an optical multiplexing unit 40 is provided on the optical transmission path 45 between subscriber device 10 and subscriber device 20, it becomes possible to transmit a control signal to a subscriber device even after the optical path has been opened.

[0033] (Modification of the first embodiment) When the control signal is an AMCC signal whose signal band does not overlap with the signal band of the main signal, the subscriber device 20 may be configured to include an optical receiving unit 21 shown in FIG. 4. FIG. 4 is a diagram showing another configuration of the subscriber device 20 in the first embodiment. FIG. 4 shows the configuration of the optical receiving unit that receives an optical signal in the subscriber device 20. The subscriber device 20 includes an optical receiving unit 21a. The optical receiving unit 21a includes a PD 23 and an LPF 24. The PD 23 converts the input optical signal into an electrical signal. The electrical signal converted by the PD 23 is branched and input to the LPF 24. The LPF 24 separates the AMCC signal from the main signal in the electrical stage to obtain the AMCC signal.

[0034] As described above, in the configuration of Figure 4, the wavelength carrying the main signal and the wavelength carrying the AMCC signal are detected together, then branched and demodulated separately, making it possible to receive both the main signal and the AMCC signal with a simple optical receiving unit configuration. Note that the wavelength of the AMCC signal must be set in the management and control device 30 so that the beat components of the wavelength carrying the main signal and the wavelength carrying the AMCC signal do not overlap with the AMCC signal component and the main signal component. The wavelength of the AMCC signal only needs to satisfy this condition, and in an optical communication system in which multiple optical paths are wavelength-multiplexed, it is not necessary to change the wavelength of the AMCC signal for each optical path.

[0035] Here, when the subscriber device 10 transmits a control signal for the management control device 30 as an AMCC signal by superimposing it on a frequency whose signal band does not overlap with that of the main signal, the management control device 30 sets the transmission timing or frequency of the AMCC signal in the subscriber device 10 so that the AMCC signal is time division multiplexed (TDM) or frequency division multiplexed (FDM) after detection so that the AMCC signal remaining at the same wavelength as the main signal and the AMCC signal carried at a wavelength different from that of the main signal (for example, λc) do not interfere with each other after detection in the optical receiving unit 21 of the subscriber device 20 shown in Figure 4.

[0036] The processes of steps S102 and S103 shown in FIG. 3 may be executed before the process of step S101.

[0037] (Second embodiment) In the second embodiment, a configuration for performing two-way communication will be described. Fig. 5 is a diagram showing an example of the configuration of an optical communication system 1a in the second embodiment. The optical communication system 1a includes a subscriber device 10, a subscriber device 20, a management and control device 30a, and multiple optical multiplexing units 40-1 and 40-2. Although Fig. 5 shows a configuration in which the optical communication system 1a includes one subscriber device 10 and one subscriber device 20, multiple subscriber devices 10 and multiple subscriber devices 20 may be included.

[0038] In the second embodiment, the subscriber device 10 converts the main signal into an optical signal with a wavelength λs1 and transmits it to the optical transmission line 45. Specifically, the subscriber device 10 converts the main signal into an optical signal with a wavelength λs1, which is the wavelength instructed by the management control device 30a, and transmits it to the optical transmission line 45.

[0039] In the second embodiment, the subscriber device 20 converts the main signal into an optical signal with a wavelength λs2 and transmits it to the optical transmission line 45. Specifically, the subscriber device 20 converts the main signal into an optical signal with a wavelength λs2, which is the wavelength instructed by the management control device 30a, and transmits it to the optical transmission line 45.

[0040] The subscriber devices 10 and 20 have the configuration of the optical receiving unit 21 shown in FIG. 2 or the optical receiving unit 21a shown in FIG.

[0041] The management control device 30a includes a plurality of optical transmitters 31-1 to 31-2 and a plurality of control signal generators 32-1 to 32-2. The optical transmitter 31-1 is configured with a control signal transmitter 33-1. The optical transmitter 31-1 and the optical multiplexer 40-1 are connected via an optical transmission path. The optical transmitter 31-2 is configured with a control signal transmitter 33-2. The optical transmitter 31-2 and the optical multiplexer 40-2 are connected via an optical transmission path.

[0042] The control signal generator 32-1 generates a control signal for a destination to be controlled (in the second embodiment, the subscriber device 20). The control signal transmitter 33-1 converts the control signal generated by the control signal generator 32-1 into an optical signal with a wavelength (for example, wavelength λc2) different from the wavelength λs1 of the optical signal (main signal) transmitted by the subscriber device 10. The control signal transmitter 33-1 transmits the converted optical signal to the optical multiplexer 40-1.

[0043] The control signal generator 32-2 generates an AMCC signal for the destination to be controlled (in the second embodiment, the subscriber device 10). The control signal transmitter 33-2 converts the control signal generated by the control signal generator 32-2 into an optical signal with a wavelength (for example, wavelength λc1) different from the wavelength λs2 of the optical signal (main signal) transmitted by the subscriber device 20. The control signal transmitter 33-2 transmits the converted optical signal to the optical multiplexer 40-2.

[0044] 5, optical multiplexers 40-1 and 40-2 are provided on an optical transmission line 45. An optical signal with wavelength λs1 transmitted by the subscriber device 10 and an optical signal with wavelength λc2 transmitted by the control signal transmitter 33-1 are input to the optical multiplexer 40-1. The optical multiplexer 40-1 multiplexes the input optical signal with wavelength λs1 with the optical signal with wavelength λc2. The optical multiplexer 40-1 outputs the multiplexed optical signal to the subscriber device 20 via the optical transmission line 45. Note that if an optical signal from the subscriber device 10 is not input to the optical multiplexer 40-1, the optical multiplexer 40-1 will output only the optical signal with wavelength λc2 transmitted by the control signal transmitter 33-1 to the subscriber device 20 via the optical transmission line 45.

[0045] The optical multiplexer 40-2 receives an optical signal with wavelength λs2 transmitted by the subscriber device 20 and an optical signal with wavelength λc1 transmitted by the control signal transmitter 33-2. The optical multiplexer 40-2 multiplexes the input optical signal with wavelength λs2 with the optical signal with wavelength λc1. The optical multiplexer 40-2 outputs the multiplexed optical signal to the subscriber device 10 via the optical transmission path 45. Note that if an optical signal from the subscriber device 20 is not input to the optical multiplexer 40-2, the optical multiplexer 40-2 will output only the optical signal with wavelength λc1 transmitted by the control signal transmitter 33-2 to the subscriber device 10 via the optical transmission path 45.

[0046] According to the optical communication system 1a of the second embodiment configured as above, it is possible to obtain the same effects as those of the first embodiment in bidirectional communication.

[0047] (Modification of the second embodiment) The optical communication system 1a may be modified in the same manner as the first embodiment. FIG. 5 shows a configuration in which optical signals transmitted and received in both directions flow through the same optical fiber core, but the configuration may also include a section in which optical signals transmitted and received in both directions flow through different optical fiber cores.

[0048] (Third embodiment) In the third embodiment, a configuration will be described in which, in addition to the configuration of the second embodiment, a plurality of optical switches are provided between subscriber devices. 6 is a diagram showing an example of the configuration of an optical communication system 1b according to the third embodiment. The optical communication system 1b includes a plurality of subscriber devices 10-1 to 10-N (N is an integer equal to or greater than 2), subscriber devices 20-1 to 20-N, a management and control device 30b, a plurality of optical multiplexing units 40-1-1 to 40-1-N and 40-2-1 to 40-2-N, and a plurality of optical SWs 50-1 to 50-2.

[0049] In the third embodiment, each subscriber device 10 is connected to an optical SW 50-1 via an optical transmission line, and each subscriber device 20 is connected to an optical SW 50-2 via an optical transmission line. The optical SW 50-1 and the optical SW 50-2 are connected via multiple optical transmission lines 45-1 to 45-N. Each subscriber device 10 converts a main signal into an optical signal and transmits it to the optical SW 50-1. Each subscriber device 20 converts a main signal into an optical signal and transmits it to the optical SW 50-2. In the configuration shown in FIG. 6, the optical SW 50-1 and the optical SW 50-2 are connected via multiple optical transmission lines 45-1 to 45-N, but they may also be connected via a single optical transmission line using wavelength division multiplexing. In this case, each subscriber device 10 converts a main signal into an optical signal with a different wavelength and transmits it to the optical SW 50-1. Each subscriber device 20 converts a main signal into an optical signal with a different wavelength and transmits it to the optical SW 50-2.

[0050] The management control device 30b includes a plurality of optical transmitters 31b-1 to 31b-2, a plurality of control signal generators 32b-1 to 32b-2, and a plurality of controllers 34-1 to 34-2. The optical transmitter 31b-1 is composed of a plurality of control signal transmitters 33-1-1 to 33-1-N. In this manner, the optical transmitter 31b-1 includes the same number of control signal transmitters 33-1 as the number of optical transmission paths 45. Each control signal transmitter 33-1 is connected to a respective optical multiplexer 40-1 provided on the optical transmission path 45 via the optical transmission path. The optical transmitter 31b-2 is composed of a plurality of control signal transmitters 33-2-1 to 33-2-N. In this manner, the optical transmitter 31b-2 includes the same number of control signal transmitters 33-2 as the number of optical transmission paths 45. Each control signal transmitter 33-2 is connected to a respective optical multiplexer 40-2 provided on the optical transmission path 45 via the optical transmission path.

[0051] The control signal generator 32b-1 generates a control signal for each of the destinations to be controlled (in the third embodiment, the subscriber devices 20-1 to 20-N). The control signal generator 32b-1 outputs the generated control signal to a control signal transmitter 33-1 connected to an optical multiplexer 40-1 provided in an optical transmission path 45 to which the destination subscriber device 20 is connected.

[0052] The control signal generating unit 32b-1 may store information indicating which optical transmission path 45 each subscriber device 20 is connected to, and identify the optical transmission path 45 to which the destination subscriber device 20 is connected.

[0053] The control signal transmitters 33-1-1 to 33-1-N convert the control signal generated by the control signal generator 32b-1 into an optical signal having a wavelength different from the wavelength of the optical signal (main signal) transmitted by the subscriber devices 10-1 to 10-N. For example, each of the control signal transmitters 33-1-1 to 33-1-N converts the control signal generated by the control signal generator 32b-1 into an optical signal having a wavelength different from the wavelength of the optical signal (main signal) transmitted by the subscriber device 10 connected to the optical transmission path 45 on which the optical multiplexer 40-1 is connected.

[0054] The control signal generator 32b-2 generates a control signal for each of the destinations to be controlled (in the third embodiment, the subscriber devices 10-1 to 10-N). The control signal generator 32b-2 outputs the generated control signal to a control signal transmitter 33-2 connected to an optical multiplexer 40-2 provided in an optical transmission path 45 to which the destination subscriber device 10 is connected.

[0055] The control signal generating unit 32b-2 may store information indicating which optical transmission path 45 each subscriber device 10 is connected to, and identify the optical transmission path 45 to which the destination subscriber device 10 is connected.

[0056] The control signal transmitters 33-2-1 to 33-2-N convert the control signals generated by the control signal generator 32b-2 into optical signals with wavelengths different from the wavelengths of the optical signals (main signals) transmitted by the subscriber devices 20-1 to 20-N. For example, each of the control signal transmitters 33-2-1 to 33-2-N converts the control signals generated by the control signal generator 32b-2 into optical signals with wavelengths different from the wavelengths of the optical signals (main signals) transmitted by the subscriber devices 20 connected to the optical transmission path 45 on which the optical multiplexer 40-2 is connected.

[0057] The control unit 34-1 includes an optical SW control unit 35-1 and a subscriber device management control unit 36-1. The optical SW control unit 35-1 sets up connections between ports of the optical SW 50-2. The subscriber device management control unit 36-1 opens an optical path when a new subscriber device 20 is connected to the optical SW 50-2.

[0058] The control unit 34-2 includes an optical SW control unit 35-2 and a subscriber device management control unit 36-2. The optical SW control unit 35-2 sets up connections between ports of the optical SW 50-1. The subscriber device management control unit 36-2 opens an optical path when a new subscriber device 10 is connected to the optical SW 50-1. The control units 34-1 and 34-2 may be configured with one or more processors.

[0059] The optical SW50-1 has a plurality of first ports and a plurality of second ports. A plurality of subscriber devices 10-1 to 10-N are connected to the first port of the optical SW50-1 via optical transmission lines, and a plurality of optical transmission lines 45-1 to 45-N are connected to the second port of the optical SW50-1. An optical signal input to one port of the optical SW50-1 is output from another port. For example, an optical signal input to the first port of the optical SW50-1 is output from the second port.

[0060] The optical SW50-2 has a plurality of first ports and a plurality of second ports. A plurality of subscriber devices 20-1 to 20-N are connected to the first port of the optical SW50-2 via optical transmission lines, and a plurality of optical transmission lines 45-1 to 45-N are connected to the second port of the optical SW50-2. An optical signal input to one port of the optical SW50-2 is output from another port. For example, an optical signal input to the first port of the optical SW50-2 is output from the second port.

[0061] 6, the subscriber device 10-1 is connected to the optical transmission line 45-1 via the optical SW 50-1, and is connected to the subscriber device 20-1 via the optical SW 50-2. Consider the process of multiplexing a control signal addressed to the subscriber device 20-1 with an optical signal transmitted from the subscriber device 10-1 to the subscriber device 20-1. The control signal transmitter 33-1-1 of the management and control device 30b converts the control signal generated by the control signal generator 32b-1 into an optical signal with a wavelength different from the wavelength of the optical signal (main signal) transmitted by the subscriber device 10-1. The control signal transmitter 33-1-1 transmits the converted optical signal to the optical multiplexer 40-1-1.

[0062] The optical multiplexer 40-1-1 receives the optical signal transmitted by the subscriber device 10-1 and the optical signal transmitted by the control signal transmitter 33-1-1. The optical signal transmitted by the subscriber device 10-1 and the optical signal transmitted by the control signal transmitter 33-1-1 are optical signals of different wavelengths. The optical multiplexer 40-1-1 multiplexes the input optical signal with the optical signal. The optical signal multiplexed by the optical multiplexer 40-1-1 is output to the subscriber device 20-1 via the optical transmission path 45 and the optical SW 50-2.

[0063] According to the optical communication system 1b of the third embodiment configured as above, even when a plurality of subscriber devices 10 and 20 are provided, it is possible to obtain the same effects as those of the first embodiment.

[0064] (Modification of the third embodiment) The optical communication system 1b may be modified in the same manner as the first embodiment. 6, the management control device 30b needs to include the same number of control signal transmitters 33-1 and 33-2 as the number of optical transmission paths 45. Therefore, in order to reduce the number of control signal transmitters 33-1 and 33-2, an optical switch may be provided between the optical transmitter 31b-1 and each of the optical multiplexers 40-2-1 to 40-2-N, and between the optical transmitter 31b-2 and each of the optical multiplexers 40-1-1 to 40-1-N. In this configuration, each of the optical transmitters 31b-1 and 31b-2 may include one control signal transmitter 33-1 and 33-2. The output of the control signal transmitter 33-1 may be switched by the optical switch to output it to one of the optical multiplexers 40-1-1 to 40-1-N, and the output of the control signal transmitter 33-2 may be switched by the optical switch to output it to one of the optical multiplexers 40-2-1 to 40-2-N. As a result, it is possible to reduce the number of control signal transmitters.

[0065] Some of the functional units of the management control devices 30, 30a, and 30b in the above-described embodiments may be implemented by a computer. In this case, a program for implementing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed. Note that the term "computer system" here includes hardware such as an OS and peripheral devices.

[0066] Furthermore, "computer-readable recording media" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Furthermore, "computer-readable recording media" may also include devices that dynamically store programs for a short period of time, such as communication lines used when transmitting programs over networks like the Internet or over communication lines like telephone lines, or devices that store programs for a fixed period of time, such as volatile memory within the computer systems that serve as servers or clients. Furthermore, the programs may be programs that implement some of the aforementioned functions, or may be programs that can realize the aforementioned functions in combination with programs already stored in the computer system, or may be programs that are implemented using programmable logic devices such as FPGAs.

[0067] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention. [Industrial Applicability]

[0068] The present invention is applicable to optical communication systems that use control signals (for example, AMCC signals). [Explanation of symbols]

[0069] 10, 10-1 to 10-N... subscriber device, 20, 20-1 to 20-N... subscriber device, 21, 21a... optical receiver, 22... wavelength demultiplexer, 23-1, 23-2... PD, 24... LPF, 30, 30a, 30b... management and control device, 31, 31-1, 31-2, 31b-1, 31b-2... optical transmitter, 32, 32-1, 32-2, 32b-1, 32b-2... control signal generator, 33, 33-1, 33-2, 33-1-1 to 33-1-N, 33-2-1 to 33-2-N... control signal transmitter, 34-1, 34-2... control unit, 35-1, 35-2... optical SW control unit, 36-1, 36-2... subscriber device management and control unit, 40, 40-1, 40-2, 40-1-1~40-1-N, 40-2-1~40-2-N...Optical multiplexing section, 50-1, 50-2...Optical SW

Claims

1. An optical communication system comprising a management control device that manages communications between one or more first subscriber devices and one or more second subscriber devices provided at positions opposite the first subscriber devices, The management control device a control signal generating unit for generating a control signal to be transmitted to the first subscriber device and used for management and control; an optical transmitter that converts the control signal generated by the control signal generator into an optical signal having a wavelength different from that of a main signal transmitted by a second subscriber unit that communicates with the first subscriber unit, and transmits the optical signal; Equipped with an optical multiplexing unit that is provided on a communication path between the first subscriber device and the second subscriber device and at a location different from the management control device, and that multiplexes a main signal transmitted by the second subscriber device and the optical signal transmitted from the optical transmitting unit of the management control device; Equipped with When the control signal is an AMCC (Auxiliary Management and Control Channel) signal whose signal band does not overlap with the signal band of the main signal, the first subscriber device a receiving unit that converts the optical signal multiplexed by the optical multiplexing unit into an electrical signal; a filter for obtaining the control signal from the electrical signal; An optical communication system comprising:

2. An optical communication system comprising a management control device that manages communications between one or more first subscriber devices and one or more second subscriber devices provided at positions opposite the first subscriber devices, The management control device a control signal generating unit for generating a control signal to be transmitted to the first subscriber device and used for management and control; an optical transmitter that converts the control signal generated by the control signal generator into an optical signal having a wavelength different from that of a main signal transmitted by a second subscriber unit that communicates with the first subscriber unit, and transmits the optical signal; Equipped with an optical multiplexing unit that is provided on a communication path between the first subscriber device and the second subscriber device and at a location different from the management control device, and that multiplexes a main signal transmitted by the second subscriber device and the optical signal transmitted from the optical transmitting unit of the management control device; Equipped with When a plurality of the first subscriber devices and a plurality of the second subscriber devices are provided, the number of optical multiplexing units is equal to the number of communication paths between the first subscriber unit and the second subscriber unit; an optical switch provided between the optical transmitting unit and each optical multiplexing unit, which receives an optical signal transmitted from the optical transmitting unit as an input and switches a path to connect a port through which the optical signal is input to an output port to which each optical multiplexing unit is connected; The optical communication system further comprises:

3. the first subscriber device a wavelength demultiplexing unit that demultiplexes the optical signal multiplexed by the optical multiplexing unit into a first optical signal and a second optical signal; a first receiving unit that converts the first optical signal into a main electrical signal; a second receiving unit that converts the second optical signal into an electrical control signal; The optical communication system of claim 2 , comprising:

4. When a plurality of the first subscriber devices and a plurality of the second subscriber devices are provided, the number of the optical transmitters and the optical multiplexers is equal to the number of communication paths between the first subscriber unit and the second subscriber unit; 2. The optical communication system according to claim 1, wherein each optical transmitter converts the control signal generated by the control signal generator into an optical signal having a wavelength different from the wavelength of a main signal transmitted by the second subscriber device in each communication path, and transmits the optical signal.

5. the control signal generating unit includes a first control signal generating unit and a second control signal generating unit; the optical transmitter includes a first optical transmitter and a second optical transmitter, the optical multiplexing unit includes a first optical multiplexing unit and a second optical multiplexing unit, the first control signal generating unit generates a control signal to be transmitted to the first subscriber device and used for management and control; the first optical transmitter converts the control signal generated by the first control signal generator into an optical signal having a wavelength different from the wavelength of a main signal transmitted by the second subscriber device, and transmits the optical signal; the first optical multiplexing unit is provided on a communication path between the first subscriber unit and the second subscriber unit, and multiplexes a main signal transmitted by the second subscriber unit with the optical signal transmitted from the first optical transmitting unit; the second control signal generating unit generates a control signal to be transmitted to the second subscriber device and used for management and control; the second optical transmitter converts the control signal generated by the second control signal generator into an optical signal having a wavelength different from the wavelength of a main signal transmitted by the first subscriber device, and transmits the optical signal; 5. The optical communication system according to claim 1, wherein the second optical multiplexing unit is provided on a communication path between the first subscriber unit and the second subscriber unit, and multiplexes a main signal transmitted by the first subscriber unit with the optical signal transmitted from the second optical transmitting unit.

6. A management control device that manages communications between one or more first subscriber devices and one or more second subscriber devices provided at positions opposite the first subscriber devices, a control signal generating unit for generating a control signal to be transmitted to the first subscriber device and used for management and control; an optical transmitter that converts the control signal generated by the control signal generator into an optical signal having a wavelength different from that of a main signal transmitted by a second subscriber device that communicates with the first subscriber device, and transmits the optical signal to an optical multiplexer that is provided on a communication path between the first subscriber device and the second subscriber device and at a location different from the management control device, and that multiplexes the main signal transmitted by the second subscriber device and the optical signal transmitted by the management control device; Equipped with When the control signal is an AMCC (Auxiliary Management and Control Channel) signal whose signal band does not overlap with the signal band of the main signal, the first subscriber unit includes a receiving unit that converts the optical signal multiplexed by the optical multiplexing unit into an electrical signal, and a filter that acquires the control signal from the electrical signal; A management control device comprising:

7. A management control device that manages communications between one or more first subscriber devices and one or more second subscriber devices provided at positions opposite the first subscriber devices, a control signal generating unit for generating a control signal to be transmitted to the first subscriber device and used for management and control; an optical transmitter that converts the control signal generated by the control signal generator into an optical signal having a wavelength different from that of a main signal transmitted by a second subscriber device that communicates with the first subscriber device, and transmits the optical signal to an optical multiplexer that is provided on a communication path between the first subscriber device and the second subscriber device and at a location different from the management control device, and that multiplexes the main signal transmitted by the second subscriber device and the optical signal transmitted by the management control device; Equipped with When a plurality of the first subscriber devices and a plurality of the second subscriber devices are provided, the number of optical multiplexing units is equal to the number of communication paths between the first subscriber unit and the second subscriber unit; an optical switch is provided between the optical transmitter and each optical multiplexer, which receives an optical signal transmitted from the optical transmitter and switches a path to connect a port that receives the optical signal and an output port to which each optical multiplexer is connected; Management control device.

8. A control signal transmission method in an optical communication system having a management control device that manages communications between one or more first subscriber devices and one or more second subscriber devices provided at positions opposite the first subscriber devices, comprising: The management control device generating a control signal used for management and control purposes to be transmitted to the first subscriber device; converting the generated control signal into an optical signal having a wavelength different from the wavelength of a main signal transmitted by a second subscriber device communicating with the first subscriber device, and transmitting the optical signal; an optical multiplexing unit is provided on a communication path between the first subscriber device and the second subscriber device and at a position different from the management control device, and multiplexes a main signal transmitted by the second subscriber device and the optical signal transmitted from the management control device; When the control signal is an AMCC (Auxiliary Management and Control Channel) signal whose signal band does not overlap with the signal band of the main signal, the first subscriber device: converting the optical signal multiplexed by the optical multiplexing unit into an electrical signal; A control signal transmission method for acquiring the control signal from the electrical signal.

9. A control signal transmission method in an optical communication system having a management control device that manages communications between one or more first subscriber devices and one or more second subscriber devices provided at positions opposite the first subscriber devices, comprising: The management control device generating a control signal used for management and control purposes to be transmitted to the first subscriber device; converting the generated control signal into an optical signal having a wavelength different from the wavelength of a main signal transmitted by a second subscriber device communicating with the first subscriber device, and transmitting the optical signal; an optical multiplexing unit is provided on a communication path between the first subscriber device and the second subscriber device and at a position different from the management control device, and multiplexes a main signal transmitted by the second subscriber device and the optical signal transmitted from the management control device; When a plurality of the first subscriber devices and a plurality of the second subscriber devices are provided, the number of optical multiplexing units is equal to the number of communication paths between the first subscriber unit and the second subscriber unit; an optical switch is provided between an optical transmitter that transmits the optical signal and each optical multiplexer, and switches a path using the optical signal transmitted from the optical transmitter as an input so as to connect a port that inputs the optical signal with an output port to which each optical multiplexer is connected; Control signal transmission method.

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