Optical communication device and optical communication path opening method

Abstract

An optical communication device is provided with: a first optical multiplexer / demultiplexer unit that branches and outputs a control signal and a main signal light transmitted at different wavelengths from at least one newly connected subscriber device; an optical distribution unit having a plurality of first ports and a plurality of second ports, the optical distribution unit inputting at least the main signal light output by the first optical multiplexing / demultiplexing unit from any one of the plurality of first ports and outputting the main signal light from any one of the plurality of second ports; a detection unit which is provided inside or outside the light distribution unit and detects the main signal light; a subscriber device management control unit that identifies, on the basis of the main signal light detected by the detection unit, a port of the light distribution unit to which at least one newly connected subscriber device is connected; and an optical distribution control unit that controls the connection between the ports of the optical distribution unit such that the primary signal light transmitted from the newly connected at least one subscriber device is transferred to the subscriber device that is the communication partner.

Description

Technical Field

[0001] The invention relates to an optical communication device and an optical communication path opening method. Background Art

[0002] In conventional optical communication systems, in order for a subscriber device to communicate, it is necessary to open an optical path for connecting to a subscriber device that is a communication partner. Figure 8 and Fig. 9 1 is a diagram for explaining a method of opening an optical path in a conventional optical communication system 100. Figure 8 As shown, 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, a plurality of optical distribution units 500-1 to 500-2, and a plurality of wavelength multiplexing and demultiplexing units 550-1 to 550-2.

[0003] In addition, it is assumed that the subscriber device 200-1 is not connected to the optical distribution unit 500-1, the subscriber devices 200-2 to 200-3 are connected to the optical distribution unit 500-1 via an optical transmission path, and the subscriber devices 300-1 to 300-3 are connected to the optical distribution unit 500-2 via an optical transmission path. The optical distribution unit 500-1 and the optical distribution unit 500-2 are connected via the optical communication NW 600 and the wavelength multiplexing / demultiplexing units 550-1 to 550-2 constituted by the optical transmission path. The control unit 400-1 manages the subscriber device 200 and controls the operation of the optical distribution unit 500-1. The control unit 400-2 manages the subscriber device 300 and controls the operation of the optical distribution unit 500-2.

[0004] Assume that when a user wants to start communication via the subscriber device 200-1, the subscriber device 200-1 is newly connected to the optical distribution unit 500-1. At the time of the initial connection of the subscriber device 200-1, the optical distribution control unit 410 sets the connection between the ports of the optical distribution unit 500-1 so that the subscriber device 200-1 communicates with the subscriber device management control unit 420. As a result, the information required for registration and authentication of the subscriber device 200-1 can be exchanged between the subscriber device 200-1 and the subscriber device management control unit 420, or the subscriber device management control unit 420 can instruct the subscriber device 200-1 on the light wavelength used for transmission and reception. A control signal called AMCC (Auxiliary Management and Control Channel) can be used as a signal for management and control of the subscriber device. The AMCC signal includes, for example, status information indicating the transmission and reception wavelength of the optical transceiver, the transmission light intensity, the temperature, etc.

[0005] When the registration and authentication of the subscriber device 200-1, the wavelength setting, etc. are completed, the optical distribution control unit 410 Fig. 9 As shown in FIG. 1 , the port connection settings of the optical distribution unit 500-1 are changed so that the optical signal transmitted from the subscriber device 200-1 is forwarded to the subscriber device 300 (for example, the subscriber device 300-1) as the communication partner. Similarly, the control unit 400-2 changes the port connection settings of the optical distribution unit 500-2 so that the optical signal transmitted from the subscriber device 200-1 is forwarded to the subscriber device 300 (for example, the subscriber device 300-1) as the communication partner. As a result, as shown in FIG. Fig. 9 As shown, an optical path connecting the subscriber device 200-1 and the subscriber device 300-1 can be opened.

[0006] However, in Figure 8 and Fig. 9 In the structure of the optical communication system 100 shown in FIG. 1 , once the optical path is opened, there is no control channel for transmitting control signals between the control unit 400 and the subscriber devices 200 and 300. Fig.10 The structure of the optical communication system 150 shown is such that the control unit 400 can exchange control signals with the plurality of subscriber devices 200 and 300 even after the optical path is once opened.

[0007] Fig.10 1 is a diagram showing a configuration example of a conventional optical communication system 150. Fig.10 As shown, the conventional optical communication system 150 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, a plurality of optical distribution units 500-1 to 500-2, a plurality of wavelength multiplexing / demultiplexing units 550-1 to 550-2, a plurality of first optical multiplexing / demultiplexing units 610-1 to 610-3, a second optical multiplexing / demultiplexing unit 620, a plurality of first optical multiplexing / demultiplexing units 630-1 to 630-3, and a second optical multiplexing / demultiplexing unit 640. The optical communication system 150 is configured to Figure 8 and Fig. 9 The optical communication system 100 shown in the figure is additionally provided with a plurality of first optical multiplexing / demultiplexing sections 610 - 1 to 610 - 3 , a second optical multiplexing / demultiplexing section 620 , a plurality of first optical multiplexing / demultiplexing sections 630 - 1 to 630 - 3 , and a second optical multiplexing / demultiplexing section 640 .

[0008] A plurality of first optical multiplexing / demultiplexing sections 610-1 to 610-3 are arranged between a plurality of subscriber devices 200-1 to 200-3 and an optical distribution section 500-1. A second optical multiplexing / demultiplexing section 620 is arranged between a plurality of first optical multiplexing / demultiplexing sections 610-1 to 610-3 and a control section 400-1. A plurality of first optical multiplexing / demultiplexing sections 630-1 to 630-3 are arranged between a plurality of subscriber devices 300-1 to 300-3 and an optical distribution section 500-2. A second optical multiplexing / demultiplexing section 640 is arranged between a plurality of first optical multiplexing / demultiplexing sections 630-1 to 630-3 and a control section 400-2.

[0009] The subscriber devices 200-1 to 200-3 output uplink control signals to the control unit 400-1 at a wavelength different from that of the optical carrier carrying the main signal (hereinafter referred to as "main signal light"). The plurality of first optical multiplexing / demultiplexing units 610-1 to 610-3 forward the uplink control signals sent from the subscriber devices 200-1 to 200-3 to the second optical multiplexing / demultiplexing unit 620. The second optical multiplexing / demultiplexing unit 620 multiplexes the uplink control signals forwarded from the plurality of first optical multiplexing / demultiplexing units 610-1 to 610-3, and outputs them to the control unit 400-1. The control unit 400-2 outputs downlink control signals to the plurality of subscriber devices 300-1 to 300-3 at a wavelength different from that of the main signal light. The second optical multiplexing / demultiplexing unit 640 branches the downlink control signals output from the control unit 400-2, and outputs them to the plurality of first optical multiplexing / demultiplexing units 630-1 to 630-3. The plurality of first optical multiplexing / demultiplexing sections 630-1 to 630-3 wavelength-multiplex the downlink control signal and the main signal light, and output the multiple signal signals to the plurality of subscriber devices 300-1 to 300-3.

[0010] According to the above structure, the control units 400-1 to 400-2 exchange registration and authentication information and information required for opening the optical path with the subscriber devices 200 and 300 before the optical path is opened, via the plurality of first optical multiplexing and demultiplexing units 610-1 to 610-3 and the second optical multiplexing and demultiplexing units 620, or the plurality of first optical multiplexing and demultiplexing units 630-1 to 630-3 and the second optical multiplexing and demultiplexing units 640. Similarly, the control units 400-1 to 400-2 can exchange control information with the subscriber devices 200 and 300 after the optical path is opened, via the plurality of first optical multiplexing and demultiplexing units 610-1 to 610-3 and the second optical multiplexing and demultiplexing units 620, or the plurality of first optical multiplexing and demultiplexing units 630-1 to 630-3 and the second optical multiplexing and demultiplexing units 640.

[0011] Prior art literature Non-patent literature Non-patent document 1: Takuya Kanai, Kazuki Honda, Yasuki Kaneko, Shinhara Kazuki, Junichi Yoshida, "All-Photonics Network Photonic Gateway," Xinkai Association Conference, B-8-20, March 2021. Summary of the invention

[0012] Problems to be solved by the invention In order to open an optical path for a newly connected subscriber device, after completing registration and authentication of the newly connected subscriber device, wavelength setting, etc., the optical distribution control unit needs to set the port-to-port connection of the optical distribution unit so that the main signal light sent from the newly connected subscriber device is forwarded to the subscriber device that becomes the communication partner. At this time, in order for the optical distribution control unit to appropriately change the port-to-port connection setting of the optical distribution unit, the control unit needs to identify which port of the optical distribution unit the newly connected subscriber device is connected to via the optical transmission path. However, in Fig.10 In the conventional structure shown, since the control unit cannot recognize to which port of the optical distribution unit the newly connected subscriber device is connected via the optical transmission path, there is a problem that the optical path as the optical path cannot be opened.

[0013] In view of the above situation, an object of the present invention is to provide a technology that can open an optical path that communicatively connects a newly connected subscriber device with a subscriber device that becomes a communication partner in an optical communication system having an optical multiplexing / demultiplexing unit between an optical distribution unit or a control unit and the subscriber device.

[0014] Solutions to Solve Problems One embodiment of the present invention is an optical communication device, which comprises: a first optical multiplexing / demultiplexing section, which branches and outputs a control signal and a main signal light sent from at least one newly connected subscriber device at different wavelengths; an optical distribution section, which has a plurality of first ports and a plurality of second ports, which inputs at least the main signal light branched by the first optical multiplexing / demultiplexing section from any one of the plurality of first ports, and outputs it from any one of the plurality of second ports; a detection section, which is arranged inside or outside the optical distribution section, and detects the main signal light; a subscriber device management control section, which identifies the port of the optical distribution section to which at least one newly connected subscriber device is connected based on the main signal light detected by the detection section; and an optical distribution control section, which controls the connection between the ports of the optical distribution section so that the main signal light sent from the at least one newly connected subscriber device is forwarded to the subscriber device serving as the communication partner.

[0015] One embodiment of the present invention is a method for opening an optical communication path, wherein a control signal and a main signal light sent from at least one newly connected subscriber device at different wavelengths are branched and output; an optical distribution unit having a plurality of first ports and a plurality of second ports inputs at least the branched main signal light from any one of the plurality of first ports, and outputs it from any one of the plurality of second ports; the main signal light is detected inside or outside the optical distribution unit; based on the detected main signal light, the port of the optical distribution unit to which the at least one newly connected subscriber device is connected is identified; and the connection between the ports of the optical distribution unit is controlled so that the main signal light sent from the at least one newly connected subscriber device is forwarded to the subscriber device serving as the communication partner.

[0016] Effects of the Invention According to the present invention, in an optical communication system including an optical multiplexing / demultiplexing unit between an optical distribution unit or a control unit and a subscriber device, an optical path can be opened to communicatively connect a newly connected subscriber device with a subscriber device serving as a communication partner. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a diagram showing a configuration example of the optical communication system according to the first embodiment. Figure 2 It is a sequence diagram showing the flow of the optical path opening process of the optical communication system according to the first embodiment. Figure 3 It is a sequence diagram showing the flow of the optical path opening process of the optical communication system according to the first embodiment. Figure 4 This is a diagram showing a configuration example of an optical communication system in Modification 1 of the first embodiment. Figure 5 This is a diagram showing a configuration example of an optical communication system in Modification 2 of the first embodiment. Figure 6 It is a diagram showing a configuration example of an optical communication system according to the second embodiment. Figure 7 It is a diagram showing a configuration example of the optical communication system after the optical path is opened according to the second embodiment. Figure 8 This is a diagram for explaining a method of opening an optical path in a conventional optical communication system. Fig. 9 This is a diagram for explaining a method of opening an optical path in a conventional optical communication system. Fig.10 This is a diagram showing a configuration example of a conventional optical communication system. DETAILED DESCRIPTION

[0018] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

[0019] (First Embodiment) Figure 1 1 is a diagram showing a configuration example of an optical communication system 1 according to a first embodiment. The optical communication system 1 includes a plurality of subscriber devices 10 (e.g., subscriber devices 10-1 to 10-3), a plurality of subscriber devices 15 (e.g., subscriber devices 15-1 to 15-3), a plurality of first optical multiplexing / demultiplexing sections 20 (e.g., first optical multiplexing / demultiplexing sections 20-1 to 20-3), a second optical multiplexing / demultiplexing section 30, a plurality of optical distribution sections 40 (e.g., optical distribution sections 40-1 to 40-2), a plurality of wavelength multiplexing / demultiplexing sections 50 (e.g., wavelength multiplexing / demultiplexing sections 50-1 to 50-2), a plurality of first optical multiplexing / demultiplexing sections 60 (e.g., first optical multiplexing / demultiplexing sections 60-1 to 60-3), a second optical multiplexing / demultiplexing section 70, and a management and control device 80. In the first embodiment, the case where the subscriber device 10 transmits an optical signal and the subscriber device 15 receives an optical signal transmitted from the subscriber device 10 is described as an example.

[0020] In the following description, the direction from the subscriber devices 10 and 15 toward the management control device 80 is referred to as the uplink direction, and the direction from the management control device 80 toward the subscriber devices 10 and 15 is referred to as the downlink direction. The number of subscriber devices 10, subscriber devices 15, first optical multiplexing / demultiplexing units 20 and 60, second optical multiplexing / demultiplexing units 30 and 70, optical distribution unit 40, and wavelength multiplexing / demultiplexing unit 50 included in the optical communication system 1 is not limited to Figure 1 Quantity shown.

[0021] The subscriber device 10 and the first optical multiplexing / demultiplexing unit 20, the first optical multiplexing / demultiplexing unit 20 and the second optical multiplexing / demultiplexing unit 30, the second optical multiplexing / demultiplexing unit 30, 70 and the management control device 80, the first optical multiplexing / demultiplexing unit 20 and the optical distribution unit 40-1, the optical distribution unit 40-1 and the wavelength multiplexing / demultiplexing unit 50-1, the wavelength multiplexing / demultiplexing unit 50-1 and the wavelength multiplexing / demultiplexing unit 50-2, the wavelength multiplexing / demultiplexing unit 50-2 and the optical distribution unit 40-2, the optical distribution unit 40-2 and the first optical multiplexing / demultiplexing unit 60, the first optical multiplexing / demultiplexing unit 60 and the subscriber device 15, and the first optical multiplexing / demultiplexing unit 60 and the second optical multiplexing / demultiplexing unit 70 are connected by an optical transmission path. For example, the optical transmission path is an optical fiber. The wavelength multiplexing / demultiplexing unit 50-1 and the wavelength multiplexing / demultiplexing unit 50-2 are connected by an optical communication NW75.

[0022] The subscriber device 10 includes an optical transceiver. The optical transceiver is, for example, a coherent transceiver. The subscriber device 10 transmits and receives optical signals such as a main signal and a control signal through the optical transceiver. The subscriber device 10 before the optical path is opened transmits light of a wavelength reaching the optical distribution unit 40-1 at any timing before, during, or after the exchange of information required for registration and authentication and optical path opening with the management control device 80.

[0023] The information required for opening the optical path is, for example, information on the wavelength used in transmission and reception, information on the subscriber device 15 to be communicated with, etc. In the following, the main signal light transmission timing is described without distinguishing any timing before the start of the exchange of registration and authentication and information required for opening the optical path with the management control device 80, during the exchange, or after the exchange is completed. The light of the wavelength reaching the optical distribution unit 40-1 refers to the light within the wavelength range transmitted from the port on the subscriber device 10 side of the input / output port of the first optical multiplexing / demultiplexing unit 20 to the port on the optical distribution unit 40-1 side.

[0024] The subscriber device 10 transmits light of a wavelength reaching the optical distribution unit 40-1 at the main signal light transmission timing. When the subscriber device 10 transmits light of a wavelength reaching the optical distribution unit 40 at the main signal light transmission timing, the subscriber device 10 may determine the transmission timing itself or may transmit after receiving a transmission command from the management control device 80 through a downlink control signal.

[0025] When the subscriber device 10 determines the transmission timing by itself, two or more subscriber devices 10 may transmit light of the same wavelength at the same time. On the other hand, when the transmission is performed after receiving a transmission command from the management control device 80 via a downlink control signal, if the management control device 80 sends a transmission command to each subscriber device 10, the possibility of transmitting light of the same wavelength at the same time can be avoided.

[0026] The subscriber device 10 outputs the uplink control signal to the management control device 80 as an optical signal of a wavelength different from that of the main signal light. The wavelength of the uplink control signal sent by the subscriber device 10 is within the wavelength range transmitted from the port on the subscriber device 10 side of the input / output port of the first optical multiplexing / demultiplexing unit 20 to the port on the second optical multiplexing / demultiplexing unit 30 side. In addition, the wavelengths of the uplink control signals sent by each subscriber device 10 may all be the same. The subscriber device 10 is, for example, an ONU (Optical Network Unit) installed in a subscriber's residence. In the following description, it is assumed that the subscriber device 10-1 is a subscriber device newly connected to the optical distribution unit 40-1.

[0027] The subscriber device 15 is a device that communicates with the subscriber device 10. The subscriber device 15 includes an optical transceiver. The subscriber device 15 transmits and receives optical signals such as main signals and control signals through the optical transceiver. As a process before the optical path is opened, the subscriber device 15 also performs the same process as the subscriber device 10. The subscriber device 15 receives the downlink control signal sent from the management control device 80 and the main signal light transmitted in the optical transmission path 86. The subscriber device 15 is installed in the subscriber's residence, for example.

[0028] The first optical multiplexing / demultiplexing unit 20 is provided between the subscriber device 10 and the optical distribution unit 40-1. The first optical multiplexing / demultiplexing unit 20 branches and outputs the uplink control signal and the main signal light transmitted from each subscriber device 10 at different wavelengths. In the following description, the branching performed by the first optical multiplexing / demultiplexing unit 20 includes the case of separating the uplink control signal and the main signal light, and the case of branching the uplink control signal and the main signal light at a prescribed ratio. In the case of separating the uplink control signal and the main signal light, the first optical multiplexing / demultiplexing unit 20 separates the uplink control signal and the main signal light in wavelength, outputs the separated uplink control signal to the second optical multiplexing / demultiplexing unit 30, and outputs the separated main signal light to the optical distribution unit 40-1. In the case of branching the uplink control signal and the main signal light at a prescribed ratio, the first optical multiplexing / demultiplexing unit 20 branches the uplink control signal and the main signal light at a prescribed ratio, and outputs them to the second optical multiplexing / demultiplexing unit 30 and the optical distribution unit 40-1. In the first embodiment, an optical multiplexing / demultiplexing device (for example, a wavelength filter) having wavelength selectivity is used in the first optical multiplexing / demultiplexing section 20 .

[0029] The second optical multiplexing / demultiplexing unit 30 is provided between the first optical multiplexing / demultiplexing unit 20 and the control unit 81-1. The second optical multiplexing / demultiplexing unit 30 multiplexes the uplink control signals transferred from the first optical multiplexing / demultiplexing units 20 and outputs the multiplexed signals to the control unit 81-1. The second optical multiplexing / demultiplexing unit 30 is, for example, an optical coupler.

[0030] The optical distribution unit 40-1 has P (P is an integer greater than or equal to 2) ports 41-1, Q (Q is an integer greater than or equal to 2) ports 42-1, and an optical detection unit 43-1. Since the optical distribution unit 40-2 has the same structure as the optical distribution unit 40-1, the structure of the optical distribution unit 40-1 is used as an example for explanation. An optical signal input to a port of the optical distribution unit 40 is output from another port. For example, an optical signal input to the port 41-1 of the optical distribution unit 40 is output from the port 42-1. The optical distribution unit 40 in the first embodiment is an FXC (Fiber Cross Connect) that outputs light input from each port to a port for which a connection relationship is set as a connection port for the port regardless of the wavelength. As the optical distribution unit 40 in the first embodiment, a spatial optical switch using, for example, a MEMS (Micro Electro Mechanical Systems) or a piezoelectric actuator is used. Port 41-1 is a mode of the first port, and port 42-1 is a mode of the second port.

[0031] The optical detection unit 43-1 detects an optical signal input to the port 41-1. When the optical signal is detected, the optical detection unit 43-1 notifies the management control device 80 of the detection result including the port where the optical signal is detected. The notification from the optical detection unit 43-1 to the management control device 80 may also be performed via the wire connecting the management control device 80 and the optical distribution unit 40-1. Through the notification sent from the optical detection unit 43-1, the management control device 80 can recognize the input of light to the port to which the subscriber device 10 is newly connected.

[0032] The wavelength multiplexing / demultiplexing unit 50 multiplexes or demultiplexes the input optical signal according to the wavelength. For example, the wavelength multiplexing / demultiplexing unit 50-1 multiplexes the optical signals of multiple wavelengths output from the optical distribution unit 40-1 to generate a multiplexed signal. The wavelength multiplexing / demultiplexing unit 50-1 outputs the generated multiplexed signal to the optical transmission path. For example, the wavelength multiplexing / demultiplexing unit 50-2 demultiplexes the multiplexed signal input via the optical transmission path according to each wavelength and outputs it. The wavelength multiplexing / demultiplexing unit 50 is, for example, AWG (Arrayed Waveguide Grating) or WSS (Wavelength Selective Switch).

[0033] The first optical multiplexing / demultiplexing section 60 is provided between the subscriber device 15 and the optical distribution section 40-2. The first optical multiplexing / demultiplexing section 60 wavelength-multiplexes the main signal light transmitted in the optical transmission path and the downlink control signal output from the second optical multiplexing / demultiplexing section 70, and outputs the multiplexed signals to the subscriber device 15. In the first embodiment, an optical multiplexing / demultiplexing device (e.g., a wavelength filter) having wavelength selectivity is used in the first optical multiplexing / demultiplexing section 60.

[0034] The second optical multiplexing / demultiplexing section 70 is provided between the first optical multiplexing / demultiplexing section 60 and the control section 81-2. The second optical multiplexing / demultiplexing section 70 branches the downlink control signal output from the control section 81-2 and outputs it to each first optical multiplexing / demultiplexing section 60. The second optical multiplexing / demultiplexing section 70 is, for example, an optical coupler.

[0035] The management control device 80 controls at least the subscriber devices 10 and 15 and the optical distribution unit 40. Here, the control of the subscriber devices 10 and 15 includes, for example, control of the transmission timing of the control signal, allocation of the light emission wavelength to the subscriber devices 10 and 15, light stop instruction, and wavelength change instruction. The control of the optical distribution unit 40 includes, for example, connection switching between ports of the optical distribution unit 40. The management control device 80 includes a plurality of control units 81 (for example, control units 81-1 to 81-2). Each control unit 81 controls each optical distribution unit 40 and the subscriber devices 10 and 15 accommodated in each optical distribution unit 40. For example, the control unit 81-1 controls the optical distribution unit 40-1 and the subscriber device 10 accommodated in the optical distribution unit 40-1. For example, the control unit 81-2 controls the optical distribution unit 40-2 and the subscriber device 15 accommodated in the optical distribution unit 40-2.

[0036] The control unit 81-1 includes an optical distribution control unit 82-1 and a subscriber device management control unit 83-1. The control unit 81-2 has the same structure as the control unit 81-1. The control unit 81-1 and the control unit 81-2 perform the same processing except that the control objects are different, so the optical distribution control unit 82-1 and the subscriber device management control unit 83-1 are used as examples for description.

[0037] The optical distribution control unit 82 - 1 sets and switches the connection between the ports of the optical distribution unit 40 and sets the optical path.

[0038] When a subscriber device 10 is newly connected to the optical distribution unit 40, the subscriber device management control unit 83-1 transmits a search signal for requesting a reply response signal to the subscriber device 10 newly connected to the optical distribution unit 40. The subscriber device management control unit 83-1 may periodically transmit the search signal, or may transmit the search signal only when the connection of the subscriber device 10 requesting the opening of the optical path is detected. The subscriber device management control unit 83-1 measures the round trip time (RTT) between the subscriber device 10 and the subscriber device management control unit 83-1 by exchanging the search signal, the response signal, and the subsequent signals with the subscriber device 10.

[0039] The subscriber device management control unit 83-1 performs photoelectric conversion on the uplink control signal transmitted from the subscriber device 10, and then uses the identifier included in the uplink control signal to identify the subscriber device 10 that is the transmission source of the received uplink control signal. Examples of the identifier include an ID assigned to the subscriber device 10 by the subscriber device management control unit 83-1 and a MAC (Media Access Control) address of the subscriber device 10.

[0040] When uplink control signals are sent simultaneously from multiple subscriber devices 10, there is a possibility that the uplink control signals collide. Therefore, in order to realize that the subscriber device management control unit 83-1 exchanges control signals with multiple subscriber devices 10, for example, a PON (Passive Optical Network) method can be applied. The subscriber device 10 outputs an uplink control signal including a control signal only during a time period permitted by the subscriber device management control unit 83-1, and stops outputting the uplink control signal during other time periods. That is, the uplink control signal is a burst signal light.

[0041] The subscriber device management control unit 83-1 recognizes the RTT between each subscriber device 10 and the subscriber device management control unit 83-1. Therefore, the subscriber device management control unit 83-1 refers to the RTT value and provides each subscriber device 10 with permission to transmit an uplink control signal so that the uplink control signal from the subscriber device 10 as a burst signal light does not arrive at the subscriber device management control unit 83-1 in the same time period as the uplink control signal from other subscriber devices 10.

[0042] In addition, the subscriber device management and control unit 83-1 provides permission for sending an uplink control signal to the subscriber device 10 for which the optical path has been opened, with reference to the RTT value between each subscriber device 10 and the subscriber device management and control unit 83-1, so that the uplink control signal from the subscriber device 10 for which the optical path has been opened will not arrive at the subscriber device management and control unit 83-1 during a period when an uplink control signal including a response signal may arrive at the subscriber device management and control unit 83-1, wherein the response signal is a reply from the subscriber device 10 (for example, the subscriber device 10-1) before the optical path is opened in response to a search signal from the subscriber device management and control unit 83-1.

[0043] According to the above structure, the subscriber device management control unit 83-1 exchanges registration and authentication information and information required for opening the optical path with the subscriber device 10 before the optical path is opened via the first optical multiplexing / demultiplexing unit 20 and the second optical multiplexing / demultiplexing unit 30. In addition, the subscriber device management control unit 83-1 exchanges control information with the subscriber device 10 after the optical path is opened via the first optical multiplexing / demultiplexing unit 20 and the second optical multiplexing / demultiplexing unit 30.

[0044] Furthermore, when a subscriber device 10 is newly connected to the optical distribution unit 40, the subscriber device management control unit 83-1 determines which port of the optical distribution unit 40 the subscriber device 10 newly connected to the optical distribution unit 40 is connected to based on the detection result transmitted from the optical distribution unit 40. The subscriber device management control unit 83-1 performs processing for opening an optical path by switching the connection relationship of the optical distribution unit 40 so that the determined port and the port of the subscriber device 15 to which the communication object is connected can communicate.

[0045] In the process of exchanging information required for registration, authentication, and optical path opening with a newly connected subscriber device 10, the subscriber device management control unit 83-1 takes the time point when the connection of the new subscriber device 10 is identified as a reference, and within a specified time before, after, or before and after the reference time, the port of the optical distribution unit 40-1 where the optical input is newly detected is identified as the port to which the newly connected subscriber device 10 is connected, based on the detection result obtained from the optical distribution unit 40.

[0046] The control unit 81-2 sends a downlink control signal to the subscriber device 15. The wavelength of the downlink control signal sent by the control unit 81-2 is within the wavelength range transmitted from the port on the side of the second optical multiplexing / demultiplexing unit 70 among the input / output ports of the first optical multiplexing / demultiplexing unit 60 to the port on the side of the subscriber device 15. The downlink control signal is a signal light that has been time-multiplexed with the downlink control signals sent to each subscriber device 15. After performing photoelectric conversion on the downlink control signal, the subscriber device 15 uses the identifier included in the downlink control signal to selectively receive the downlink control signal sent to the device from the time-multiplexed downlink control signal. As an identifier, for example, there can be cited an ID assigned to the subscriber device 15 by the subscriber device management control unit 83-2 possessed by the control unit 81-2, a MAC address of the subscriber device 15, and the like. The functions of the control unit 81 can be implemented by executing a program by one or more processors.

[0047] Figure 2 and Figure 3 1 is a sequence diagram showing the flow of the optical path opening process of the optical communication system 1 in the first embodiment. Figure 2 and Figure 3 In the description, it is assumed that the main signal light transmission timing is any timing during the period in which information required for registration, authentication, and optical path opening is exchanged between the subscriber device 10 and the management control device 80.

[0048] Assuming that the user connects the subscriber device 10-1 to the optical distribution unit 40-1 via the optical transmission path 85-1, the subscriber device 10 is connected to the optical distribution unit 40-1 via the optical transmission path 85-1 (step S101). The subscriber device management control unit 83-1 included in the control unit 81-1 periodically or upon receiving detection of the connection of the subscriber device 10, transmits a search signal (step S102).

[0049] After sending the search signal, the subscriber device management control unit 83-1 controls the transmission timing of the uplink control signal of the subscriber device 10 for which the optical path is already opened (step S103). Specifically, the subscriber device management control unit 83-1 refers to the RTT value of the subscriber device 10 for which the optical path is already opened, and provides transmission permission to each of the subscriber devices 10 for which the optical path is already opened, so that the transmission of the uplink control signal from other subscriber devices 10-1 does not arrive at the subscriber device management control unit 83-1 during the period when the uplink control signal including the response signal may arrive at the subscriber device management control unit 83-1, and the response signal is the response signal that the subscriber device 10-1 replies to the search signal. In this way, it is possible to avoid that when the subscriber device management control unit 83-1 receives the uplink control signal including the response signal from the subscriber device 10-1, the uplink control signal from other subscriber devices 10 arrives at the subscriber device management control unit 83-1, and the uplink control signal cannot be received.

[0050] The search signal sent from the subscriber device management control unit 83-1 is input to the second optical multiplexing / demultiplexing unit 30. The second optical multiplexing / demultiplexing unit 30 branches and outputs the input search signal. The search signal branched by the second optical multiplexing / demultiplexing unit 30 is input to each first optical multiplexing / demultiplexing unit 20. Each first optical multiplexing / demultiplexing unit 20 outputs the input search signal to the connected subscriber device 10 via the optical transmission path 85. Thus, each subscriber device 10 receives the search signal sent from the subscriber device management control unit 83-1.

[0051] The subscriber device 10-1 generates an uplink control signal including a response signal in response to receiving the search signal transmitted from the subscriber device management control unit 83-1. The subscriber device 10-1 transmits the generated uplink control signal to the optical transmission path 85-1 (step S104). The uplink control signal transmitted from the subscriber device 10-1 is input to the first optical multiplexing / demultiplexing unit 20-1 via the optical transmission path 85-1.

[0052] The first optical multiplexing / demultiplexing section 20-1 outputs the input uplink control signal to the second optical multiplexing / demultiplexing section 30. Since the wavelength of the uplink control signal transmitted by the subscriber device 10 is within the wavelength range transmitted from the port on the subscriber device 10 side among the input / output ports of the first optical multiplexing / demultiplexing section 20 to the port on the second optical multiplexing / demultiplexing section 30 side, the uplink control signal input to the first optical multiplexing / demultiplexing section 20-1 is output to the second optical multiplexing / demultiplexing section 30. In addition, in the case where the wavelength of the uplink control signal transmitted by the subscriber device 10 is not within the wavelength range transmitted from the port on the subscriber device 10 side among the input / output ports of the first optical multiplexing / demultiplexing section 20 to the port on the optical distribution section 40-1 side, the uplink control signal input to the first optical multiplexing / demultiplexing section 20-1 is not output to the optical distribution section 40-1.

[0053] The second optical multiplexing / demultiplexing section 30 multiplexes the uplink control signals output from the first optical multiplexing / demultiplexing sections 20 and outputs the multiplexed uplink control signals to the control section 81-1. Thus, the uplink control signals transmitted from the subscriber device 10-1 are transferred to the control section 81-1.

[0054] The subscriber device management control unit 83-1 included in the control unit 81-1 obtains the response signal included in the uplink control signal transmitted from the subscriber device 10-1 (step S105). Thereafter, the subscriber device management control unit 83-1 exchanges information required for optical path opening with the subscriber device 10-1 (step S106). While exchanging information required for optical path opening, the subscriber device management control unit 83-1 measures the RTT between the subscriber device management control unit 83-1 and the subscriber device 10-1 (step S107). The subscriber device management control unit 83-1 stores the measured RTT value in association with the identifier of the subscriber device 10-1.

[0055] The subscriber device 10 transmits the main signal light of the wavelength reaching the optical distribution unit 40-1 to the optical transmission path 85-1 at any timing during the exchange of registration and authentication and information required for opening the optical path with the management control device 80 (step S108). The main signal light transmitted from the subscriber device 10 is input to the first optical multiplexing / demultiplexing unit 20-1 via the optical transmission path 85-1.

[0056] The first optical multiplexing / demultiplexing unit 20-1 outputs the input main signal light to the optical distribution unit 40-1. Since the wavelength of the main signal light transmitted by the subscriber device 10 is within the wavelength range transmitted from the port on the subscriber device 10 side among the input / output ports of the first optical multiplexing / demultiplexing unit 20 to the port on the optical distribution unit 40-1 side, the main signal light input to the first optical multiplexing / demultiplexing unit 20-1 is output to the optical distribution unit 40-1. The optical detection unit 43 of the optical distribution unit 40-1 detects the main signal light output from the first optical multiplexing / demultiplexing unit 20-1 (step S109). For example, the optical detection unit 43 detects the main signal light output from the first optical multiplexing / demultiplexing unit 20-1 at the port 41-1-1. The optical detection unit 43 sends the detection result indicating that light is detected at the port 41-1 to the control unit 81-1 (step S110).

[0057] The subscriber device management control unit 83-1 included in the control unit 81-1 obtains the detection result transmitted from the optical detection unit 43. The subscriber device management control unit 83-1 identifies the port to which the subscriber device 10-1 newly connected to the optical distribution unit 40-1 is connected based on the obtained detection result (step S111). Specifically, when the subscriber device management control unit 83-1 obtains the detection result within a predetermined time before, after, or before and after the reference time, it identifies that the subscriber device 10-1 newly connected to the optical distribution unit 40-1 is connected to the port (for example, port 41-1-1) indicated by the port information included in the detection result.

[0058] On the other hand, when the detection result is not obtained within a specified time before, after, or before and after the reference time, the subscriber device management control unit 83-1 recognizes that the subscriber device 10-1 newly connected to the optical distribution unit 40-1 is not connected to the port (for example, port 41-1-1) indicated by the port information included in the detection result.

[0059] The optical distribution control units 82-1 and 82-2 set the connection relationship between the ports of the optical distribution units 40-1 and 40-2 based on the identified ports and the information of the subscriber device 15 (for example, the subscriber device 15-1) with which the subscriber device 10-1 communicates (step S112). Specifically, the optical distribution control unit 82-1 sets the connection relationship of the optical distribution unit 40-1 so that the port 41-1-1 to which the subscriber device 10-1 is connected and the port 42-1-2 connected to the optical distribution unit 40-2 to which the subscriber device 15-1 is connected are connected. The optical distribution control unit 82-1 generates a control signal for connecting the port 41-1-1 and the port 42-1-2. The optical distribution control unit 82-1 sends the generated control signal to the optical distribution unit 40-1 (step S113).

[0060] Similarly, the optical distribution control unit included in the control unit 81-2 sets the connection relationship of the optical distribution unit 40-2 so that the port to which the subscriber device 15-1 is connected and the port to which the optical distribution unit 40-1 connected to the subscriber device 10-1 is connected are connected. The optical distribution control unit included in the control unit 81-2 generates a control signal for connecting the port to which the subscriber device 15-1 is connected and the port to which the optical distribution unit 40-1 connected to the subscriber device 10-1 is connected. The optical distribution control unit included in the control unit 81-2 transmits the generated control signal to the optical distribution unit 40-2.

[0061] The optical distributors 40-1 and 40-2 set the connection relationship between the ports based on the control signal sent from the management control device 80 (step S114). As a result, an optical path is opened between the subscriber device 10-1 and the subscriber device 15-1. As a result, the subscriber device 10-1 and the subscriber device 15-1 can communicate with each other.

[0062] According to the optical communication system 1 configured as described above, the control unit 81 can identify which port of the optical distribution unit 40 the newly connected subscriber device 10 is connected to via the optical transmission path. As a result, the optical distribution control units 82-1 and 82-2 set the connection between the ports of the optical distribution units 40-1 and 40-2 so that the main signal light transmitted from the newly connected subscriber device 10 is forwarded to the subscriber device 15 that is the communication partner. Thus, in an optical communication system having an optical multiplexing / demultiplexing unit between the optical distribution unit or the control unit and the subscriber device, an optical path that can communicatively connect the newly connected subscriber device and the subscriber device that is the communication partner can be opened.

[0063] (Variant 1) exist Figure 1 In the structure shown, the main signal light sent from the subscriber device 10 to the subscriber device 15 and the main signal light sent from the subscriber device 15 to the subscriber device 10 flow in the core wire of the same optical transmission path. Conversely, it can also be configured so that there is a section in which the main signal light sent from the subscriber device 10 to the subscriber device 15 and the main signal light sent from the subscriber device 15 to the subscriber device 10 flow in the core wires of different optical transmission paths.

[0064] Figure 4 1 is a diagram showing a configuration example of an optical communication system 1a in a modification example 1 of the first embodiment. The optical communication system 1a includes a plurality of subscriber devices 10 (e.g., subscriber devices 10-1 to 10-3), a plurality of subscriber devices 15 (e.g., subscriber devices 15-1 to 15-3), a plurality of first optical multiplexing / demultiplexing sections 20 (e.g., first optical multiplexing / demultiplexing sections 20-1 to 20-3), a second optical multiplexing / demultiplexing section 30, a plurality of optical distribution sections 40 (e.g., optical distribution sections 40-1 to 40-2), a plurality of first optical multiplexing / demultiplexing sections 60 (e.g., first optical multiplexing / demultiplexing sections 60-1 to 60-3), a second optical multiplexing / demultiplexing section 70, and a management control device 80. The difference in configuration between the optical communication system 1a and the optical communication system 1 is that the optical communication system 1a does not include a wavelength multiplexing / demultiplexing section 50. The differences from the optical communication system 1 are described below.

[0065] exist Figure 4 In the case of the structure shown, the optical distribution unit 40 has a function of being able to set a transmission path for each wavelength. For example, WSS can be used as the optical distribution unit 40. This eliminates the need for the wavelength multiplexing / demultiplexing unit 50.

[0066] The subscriber device management control unit 83-1 sets the wavelengths of the signal lights in different directions to different wavelengths or provides transmission permission to the signal lights in different directions at different timings in order to prevent the reception characteristics of the signal lights in opposite directions from being deteriorated due to reflection in the optical transmission path when there is a section where the signal lights in different directions flow in the core of the same optical transmission path. When there is no section where the signal lights in different directions flow in the core of the same optical transmission path, the wavelengths of the signal lights in different directions can be set to the same wavelength.

[0067] (Variant 2) The optical communication system 1 may be configured to use an optical multiplexer / demultiplexer without wavelength selectivity as the first optical multiplexer / demultiplexer 20 , 60 , instead of using an optical multiplexer / demultiplexer with wavelength selectivity. Figure 5 1 is a diagram showing a configuration example of an optical communication system 1b in a second variant of the first embodiment. The optical communication system 1b includes a plurality of subscriber devices 10 (e.g., subscriber devices 10-1 to 10-3), a plurality of subscriber devices 15 (e.g., subscriber devices 15-1 to 15-3), a plurality of first optical multiplexing / demultiplexing sections 20b (e.g., first optical multiplexing / demultiplexing sections 20b-1 to 20b-3), a second optical multiplexing / demultiplexing section 30, a plurality of optical distribution sections 40 (e.g., optical distribution sections 40-1 to 40-2), a plurality of wavelength multiplexing / demultiplexing sections 50 (e.g., wavelength multiplexing / demultiplexing sections 50-1 to 50-3), a plurality of first optical multiplexing / demultiplexing sections 60b (e.g., first optical multiplexing / demultiplexing sections 60b-1 to 60b-3), a second optical multiplexing / demultiplexing section 70, a management control device 80, a wavelength filter 90, and a wavelength filter 91.

[0068] The optical communication system 1b differs from the optical communication system 1 in that it includes first optical multiplexing / demultiplexing sections 20b and 60b instead of the first optical multiplexing / demultiplexing sections 20 and 60 and newly includes wavelength filters 90 and 91. The differences from the optical communication system 1 will be described below.

[0069] The first optical multiplexing / demultiplexing section 20b is provided between the subscriber device 10 and the optical distribution section 40-1. The first optical multiplexing / demultiplexing section 20b branches and outputs the uplink control signal and the main signal light transmitted from each subscriber device 10 at different wavelengths. In the first optical multiplexing / demultiplexing section 20b, an optical multiplexing / demultiplexing device (e.g., an optical coupler) without wavelength selectivity is used. Therefore, the first optical multiplexing / demultiplexing section 20b branches the uplink control signal and the main signal light transmitted from each subscriber device 10 at a prescribed ratio, and outputs them to the second optical multiplexing / demultiplexing section 30 and the optical distribution section 40-1.

[0070] The first optical multiplexing / demultiplexing section 60b is provided between the subscriber device 15 and the optical distribution section 40-2. The first optical multiplexing / demultiplexing section 60b wavelength-multiplexes the main signal light transmitted in the optical transmission path and the downlink control signal output from the second optical multiplexing / demultiplexing section 70, and outputs the same to the subscriber device 15. In the first optical multiplexing / demultiplexing section 60b, an optical multiplexing / demultiplexing device (e.g., an optical coupler) without wavelength selectivity is used.

[0071] The wavelength filter 90 is provided between the second optical multiplexing / demultiplexing unit 30 and the management control device 80. The wavelength filter 90 cuts off the wavelength of the main signal light.

[0072] The wavelength filter 91 is provided between the second optical multiplexing / demultiplexing unit 70 and the management control device 80. The wavelength filter 91 cuts the wavelength of the main signal light.

[0073] After the optical path is opened, the first optical multiplexing / demultiplexing unit 20b branches off a part of the uplink control signal sent from the subscriber device 10 to the management and control device 80, and forwards it to the second optical multiplexing / demultiplexing unit 30. After the optical path is opened, the first optical multiplexing / demultiplexing unit 60b wavelength multiplexes the downlink control signal sent from the management and control device 80 to the subscriber device 15 with the main signal light. Since the first optical multiplexing / demultiplexing unit 20b is a wavelength multiplexer / demultiplexer without wavelength selectivity, the uplink control signal is also forwarded to the wavelength multiplexing / demultiplexing unit 50 side.

[0074] However, since the wavelength of the uplink control signal is different from that of the main signal light, it is cut off by the wavelength multiplexing / demultiplexing section 50 and does not pass through the wavelength multiplexing / demultiplexing section 50. Therefore, the uplink control signal and the downlink control signal will not be mixed. Figure 1 As in the structure shown, when there is no section where signal lights in different directions flow in the core of the same optical transmission path, the wavelengths of the uplink control signal and the downlink control signal can be set to the same wavelength.

[0075] In the optical communication system 1, 1a, 1b, it is also possible to configure a second optical distribution unit instead of the second optical multiplexing / demultiplexing unit 30, 70, and the optical distribution control unit 82-1 dynamically sets the connection relationship between the ports of the second optical distribution unit so that the uplink control signal reaching the second optical multiplexing / demultiplexing unit 30 is transmitted to the subscriber device management control unit 83-1. Specifically, for the subscriber device 10-1 before the optical path is opened, the existence of the subscriber device 10-1 is not known in advance in the management control device 80. Therefore, the path of the optical distribution unit can be set for the unopened ports regularly. Alternatively, when the optical detection unit 43 detects the input of light on a new port, the path of the optical distribution unit can be set for each unopened port to search for the subscriber device 10 that exchanges the control signal.

[0076] (Variant 3) In the optical communication system 1, the first optical multiplexing / demultiplexing section 20, the second optical multiplexing / demultiplexing section 30, the optical distribution section 40-1, the wavelength multiplexing / demultiplexing section 50-1, and the control section 81-1 may also constitute an optical communication device. Similarly, the first optical multiplexing / demultiplexing section 60, the second optical multiplexing / demultiplexing section 70, the optical distribution section 40-2, the wavelength multiplexing / demultiplexing section 50-2, and the control section 81-2 may also constitute an optical communication device.

[0077] In the optical communication system 1a, the first optical multiplexing / demultiplexing section 20, the second optical multiplexing / demultiplexing section 30, the optical distribution section 40-1, and the control section 81-1 can also be configured as an optical communication device. Similarly, the first optical multiplexing / demultiplexing section 60, the second optical multiplexing / demultiplexing section 70, the optical distribution section 40-2, and the control section 81-2 can also be configured as an optical communication device.

[0078] In the optical communication system 1b, the first optical multiplexing / demultiplexing part 20b, the second optical multiplexing / demultiplexing part 30, the optical distribution part 40-1, the wavelength multiplexing / demultiplexing part 50-1, the control part 81-1, and the wavelength filter 90 can also constitute an optical communication device. Similarly, the first optical multiplexing / demultiplexing part 60b, the second optical multiplexing / demultiplexing part 70, the optical distribution part 40-2, the wavelength multiplexing / demultiplexing part 50-2, the control part 81-2, and the wavelength filter 91 can also constitute an optical communication device.

[0079] (Second Embodiment) In the first embodiment, a structure in which the light detection unit is provided inside the light distribution unit is described. In the second embodiment, a structure in which the light detection unit is provided outside the light distribution unit is described.

[0080] Figure 6 1 is a diagram showing a configuration example of an optical communication system 1c according to a second embodiment. The optical communication system 1c includes a plurality of subscriber devices 10 (e.g., subscriber devices 10-1 to 10-3), a plurality of subscriber devices 15 (e.g., subscriber devices 15-1 to 15-3), a plurality of first optical multiplexing / demultiplexing sections 20 (e.g., first optical multiplexing / demultiplexing sections 20-1 to 20-3), a second optical multiplexing / demultiplexing section 30, a plurality of optical distribution sections 40c (e.g., optical distribution sections 40c-1 to 40c-2), a plurality of optical detection sections 43 (e.g., optical detection sections 43c-1 to 43c-2), a plurality of wavelength multiplexing / demultiplexing sections 50 (e.g., wavelength multiplexing / demultiplexing sections 50-1 to 50-3), a plurality of first optical multiplexing / demultiplexing sections 60 (e.g., first optical multiplexing / demultiplexing sections 60-1 to 60-3), a second optical multiplexing / demultiplexing section 70, and a management control device 80.

[0081] The optical communication system 1c differs from the optical communication system 1 in that the optical distribution units 40-1 and 40-2 are replaced with optical distribution units 40c-1 and 40c-2 and a plurality of light detection units 43 are provided outside.

[0082] The optical distribution unit 40c-1 has P ports 41-1 and Q ports 42-1. Since the optical distribution unit 40c-2 has the same structure as the optical distribution unit 40c-1, the structure of the optical distribution unit 40c-1 is used as an example for explanation. The difference between the structure of the optical distribution unit 40c-1 and the optical distribution unit 40-1 is that the optical detection unit 43-1 is not provided. The optical detection unit 43-1 is connected to the port 42-1-1 of the optical distribution unit 40c-1. In addition, the port connected to the optical detection unit 43-1 can be any port of the port 42-1. In the following description, it is assumed that the optical detection unit 43-1 is connected to the port 42-1-1 of the optical distribution unit 40c-1.

[0083] The optical distribution unit 40c-1 switches the connection relationship between the ports according to the control of the optical distribution control unit 82-1 so that each port 41-1 that does not open the optical path and the port 42-1-1 connected to the optical detection unit 43-1 are connected in sequence. The optical detection unit 43-1 detects the optical signal output from the connected port 42-1-1. When the optical detection unit 43-1 detects the optical signal, it notifies the management control device 80 of the detection result indicating the detection of the optical signal.

[0084] The structure and processing of the management control device 80 are basically the same as those of the first embodiment. For example, regarding the management control device 80, Figure 3 The processing after step S111 shown and the processing performed by the optical distribution control unit 82-1 after the transmission of the search signal are different from those in the first embodiment.

[0085] For example, after sending the search signal, the optical distribution control unit 82-1 controls the connection relationship between the ports of the optical distribution unit 40c-1 so that the ports 41-1 of the optical distribution unit 40c-1 that do not open the optical path and the port 42-1-1 connected to the optical detection unit 43-1 are connected in sequence. In addition, the optical distribution control unit 82-1 may always control the connection relationship between the ports of the optical distribution unit 40c-1, instead of controlling the connection relationship between the ports of the optical distribution unit 40c-1 after sending the search signal.

[0086] After acquiring the detection result from the optical detection unit 43-1, the subscriber device management control unit 83-1 recognizes, at the time of acquiring the detection result, the port 41-1 connected to the port 42-1-1 to which the optical detection unit 43-1 is connected as the port to which the newly connected subscriber device 10 is connected. At this time, if the subscriber device management control unit 83-1 acquires the detection result within a predetermined time before, after, or before or after the reference time, at the time of acquiring the detection result, it recognizes that the subscriber device 10-1 newly connected to the optical distribution unit 40-1 is connected to the port 41-1 connected to the port 42-1-1 to which the optical detection unit 43-1 is connected.

[0087] For example, when the subscriber device management control unit 83-1 recognizes that the port 41-1-1 is the port to which the newly connected subscriber device 10-1 is connected, the optical distribution control units 82-1 and 82-2 set the connection relationship between the ports of the optical distribution units 40-1 and 40-2 based on the recognized port 41-1-1 and the information of the subscriber device 15 (for example, the subscriber device 15-1) with which the subscriber device 10-1 communicates. Specifically, the optical distribution control unit 82-1 sets the connection relationship of the optical distribution unit 40-1 so that the port 41-1-1 to which the subscriber device 10-1 is connected and the port 42-1-2 connected to the optical distribution unit 40-2 to which the subscriber device 15-1 is connected are connected. The optical distribution control unit 82-1 generates a control signal for connecting the port 41-1-1 and the port 42-1-2. The optical distribution control unit 82-1 sends the generated control signal to the optical distribution unit 40-1.

[0088] Similarly, the optical distribution control unit included in the control unit 81-2 sets the connection relationship of the optical distribution unit 40-2 so that the port to which the subscriber device 15-1 is connected and the port to which the optical distribution unit 40-1 connected to the subscriber device 10-1 is connected are connected. The optical distribution control unit included in the control unit 81-2 generates a control signal for connecting the port to which the subscriber device 15-1 is connected and the port to which the optical distribution unit 40-1 connected to the subscriber device 10-1 is connected. The optical distribution control unit included in the control unit 81-2 transmits the generated control signal to the optical distribution unit 40-2.

[0089] The optical distribution units 40-1 and 40-2 set the connection relationship between the ports based on the control signal sent from the management control device 80. Figure 7 As shown, an optical path is opened between the subscriber device 10-1 and the subscriber device 15-1. As a result, communication can be performed between the subscriber device 10-1 and the subscriber device 15-1.

[0090] According to the optical communication system 1c configured as described above, the same effects as those of the first embodiment can be obtained.

[0091] (Variant 1) The optical communication system 1c may be modified like the optical communication system 1a or 1b shown in the first embodiment.

[0092] (Variant 2) The optical communication system 1c may also be configured to include a header detection unit instead of the light detection units 43-1 and 43-2. ​​The header detection unit is composed of a photoelectric conversion unit and a header information acquisition unit. The header detection unit is one form of a detection unit that detects the main signal light. The photoelectric conversion unit converts the optical signal output from the optical distribution units 40c-1 and 40c-2 into an electrical signal. The header information acquisition unit detects and reads the header from the electrical signal. The header information acquisition unit sends the read header information as a detection result to the management control device 80. In the case where a plurality of subscriber devices 10 simultaneously transmit light of the same wavelength, the light detection unit 43c-1 cannot distinguish between the two lights.

[0093] For example, when an uplink control signal and a signal carried by the light of the wavelength reaching the optical distribution unit 40c-1 are transmitted in Ethernet frames, the source MAC addresses of the headers of the frames including the respective signals are made the same. Thus, when the source MAC addresses of the header read out from the uplink control signal by the management control device 80 and the header read out from the signal carried by the light of the wavelength reaching the optical distribution unit 40c-1 by the header information acquisition unit are the same, the management control device 80 can identify from which port 41-1 of the optical distribution unit 40c-1 the light of the wavelength reaching the optical distribution unit 40c-1 outputted by the subscriber device 10 having the source MAC address is input and forwarded to the header information acquisition unit. As a result, it is possible to cope with a case where a plurality of subscriber devices 10 transmit the same wavelength at the same time.

[0094] (Variant 3) In the optical communication system 1c, the first optical multiplexing / demultiplexing section 20, the second optical multiplexing / demultiplexing section 30, the optical distribution section 40c-1, the optical detection section 43-1, the wavelength multiplexing / demultiplexing section 50-1, and the control section 81-1 can also constitute an optical communication device. Similarly, the first optical multiplexing / demultiplexing section 60, the second optical multiplexing / demultiplexing section 70, the optical distribution section 40c-2, the optical detection section 43-2, the wavelength multiplexing / demultiplexing section 50-2, and the control section 81-2 can also constitute an optical communication device.

[0095] The functional units of a part of the management control device 80 in the above-mentioned embodiment may also be realized by a computer. In this case, the program for realizing the function may be recorded in a computer-readable recording medium, and the computer system may read and execute the program recorded in the recording medium. In addition, the "computer system" mentioned here includes hardware such as OS (Operating System) and peripheral devices.

[0096] In addition, "computer-readable recording medium" refers to removable media such as floppy disks, magneto-optical disks, ROM (Read Only Memory), CD-ROMs, and storage devices such as hard disks built into computer systems. In addition, "computer-readable recording medium" may also include: a medium that dynamically maintains a program in a short period of time, such as a communication line when a program is sent via a network such as the Internet or a communication line such as a telephone line, and a medium that maintains a program for a certain period of time, such as a volatile memory inside a computer system that becomes a server or client in this case. In addition, the above program may be a program for realizing a part of the above functions, or a program that realizes the above functions by combining with a program already recorded in a computer system, or a program that is realized using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0097] As mentioned above, although the embodiment of the present invention is described in detail with reference to the drawings, the specific structure is not limited to this embodiment, and also includes the design etc. within the scope which does not deviate from the summary of the present invention.

[0098] Industrial Applicability The present invention can be applied to the technology for opening an optical path.

[0099] Description of Reference Numerals 1, 1a, 1b, 1c…optical communication system, 10, 15, 10-1~10-3, 15-1~15-3…subscriber device, 20, 20-1~20-3, 60, 60-1~60-3…first optical multiplexing / demultiplexing unit, 30, 70…second optical multiplexing / demultiplexing unit, 40-1, 40-2, 40c-1, 40c-2…optical distribution unit, 43-1, 43-2, 43c-1, 43c-2…optical detection unit, 50-1, 50-2…wavelength multiplexing / demultiplexing unit, 80…management control device, 81-1, 81-2…control unit, 82-1…optical distribution control unit, 83-1…subscriber device management control unit, 85-1~85-3, 86-1~86-3…optical transmission path, 90, 91…wavelength filter.

Claims

1. An optical communication device, wherein: have: A first optical multiplexing and demultiplexing section branches and outputs a control signal and a main signal light transmitted at different wavelengths from at least one newly connected subscriber device; An optical distribution unit having a plurality of first ports and a plurality of second ports, inputting at least the main signal light branched by the first optical multiplexing / demultiplexing part from any one of the plurality of first ports, and outputting from any one of the plurality of second ports; A detection unit, disposed inside or outside the optical distribution unit, and detecting the main signal light; a subscriber device management control section that identifies, based on the main signal light detected by the detection section, a port of the optical distribution section to which at least one newly connected subscriber device is connected; as well as The optical distribution control unit controls the connection between the ports of the optical distribution unit so that the main signal light transmitted from the at least one newly connected subscriber device is transferred to the subscriber device as the communication partner.

2. The optical communication device according to claim 1, wherein: In the case where the detection unit is disposed inside the light distribution unit, The detection unit detects the main signal light input to the plurality of first ports of the optical distribution unit, respectively, and outputs a detection result including information of the first port at which the main signal light is detected to the subscriber device management control unit.

3. The optical communication device according to claim 1, wherein: In the case where the detection unit is arranged outside the optical distribution unit, the detection unit is connected to any one of the plurality of second ports, and the optical distribution control unit performs control so that a first port of the plurality of first ports of the optical distribution unit that does not have an optical path opened and a second port connected to the detection unit are switched and connected in sequence, When the detection unit detects the main signal light, the detection unit outputs the detection result to the subscriber device management control unit.

4. The optical communication device according to claim 3, wherein: The subscriber device management control unit identifies, at the time point when the detection result output from the detection unit is obtained, a first port having no optical path opened among the plurality of first ports of the optical distribution unit connected to the second port connected to the detection unit as a port to which the at least one newly connected subscriber device is connected.

5. The optical communication device according to claim 3, wherein: The detection unit is composed of the following: a photoelectric conversion unit that converts the main signal light into an electrical signal; and a header information acquisition unit, detecting and reading the header from the electrical signal, The header information acquisition unit outputs the read header information as the detection result to the subscriber device management control unit, The subscriber device management control section identifies the port of the optical distribution section to which the at least one newly connected subscriber device is connected based on the information of the header and the control signal included in the detection result.

6. The optical communication device according to any one of claims 1 to 5, wherein: The subscriber device management control unit recognizes that the at least one newly connected subscriber device is connected to the optical distribution unit when the detection result detected by the detection unit is obtained within a predetermined time before, after, or before or after a reference time.

7. The optical communication device according to any one of claims 1 to 5, wherein: The subscriber device management control unit controls the sending timing of the control signal for one or more subscriber devices to which the optical path has been opened so that the control signal from the one or more subscriber devices to which the optical path has been opened will not arrive within a period during which a control signal including a response signal may arrive, and the response signal is a search signal sent for at least one of the newly connected subscriber devices and replied in response to the search signal.

8. A method for opening an optical communication path, wherein: branching and outputting a control signal and a main signal light transmitted at different wavelengths from at least one newly connected subscriber device; The optical distribution unit having a plurality of first ports and a plurality of second ports inputs at least the branched main signal light from any one of the plurality of first ports and outputs the branched main signal light from any one of the plurality of second ports; detecting the main signal light inside or outside the optical distribution unit; identifying, based on the detected main signal light, a port of the optical distribution section to which at least one newly connected subscriber device is connected; The connection between the ports of the optical distribution section is controlled so that the main signal light transmitted from the at least one newly connected subscriber device is transferred to the subscriber device as the communication partner.

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