Optical communication system and optical communication method

Abstract

With regard to this optical communication system comprising a subscriber device which is optically connected to another subscriber device in an End-to-End manner, and a management control device which controls each of the subscriber devices, the subscriber devices each include: an optical signal transmission unit which transmits an optical signal; an optical signal reception unit which receives the optical signal transmitted from the other subscriber device; and an output function unit which outputs, to an optical transmission line, the optical signal output from the optical signal transmission unit regardless of wavelength, and outputs the optical signal input from the optical transmission line to the optical signal reception unit regardless of wavelength. The management control device allocates a wavelength so that a transmission wavelength of the subscriber device is a reception wavelength of the other subscriber device, and a transmission wavelength of the other subscriber device is a reception wavelength of the subscriber device.　

Description

[Technical Field]

[0001] The present invention relates to an optical communication system and an optical communication 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 6 and 7 are diagrams for explaining a method for opening an optical path in a conventional optical communication system 100. As shown in Figure 6, 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] It is assumed that the subscriber device 200-1 is not connected to the optical SW 500-1, the subscriber devices 200-2 to 200-3 are connected to the optical SW 500-1 via optical transmission paths, and the subscriber devices 300-1 to 300-3 are connected to the optical SW 500-2 via optical transmission paths. The optical SW 500-1 and the optical SW 500-2 are connected via an optical communication NW 600 configured by the optical transmission path. 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 that when a user attempts to start communication via the subscriber device 200-1, the subscriber device 200-1 is newly connected to the optical SW 500-1. At the initial connection of the subscriber device 200-1, the optical SW control unit 410 sets up a connection between the ports of the optical SW 500-1 so that the subscriber device 200-1 communicates with the subscriber device management and control unit 420. This allows the subscriber device 200-1 and the subscriber device management and control unit 420 to exchange information necessary for registering and authenticating the subscriber device 200-1, and allows the subscriber device management and control unit 420 to instruct the subscriber device 200-1 on the emission wavelength to be used for transmission and reception. A control signal called an Auxiliary Management and Control Channel (AMCC) can be used as a signal for managing and controlling the subscriber devices. 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 (e.g., subscriber device 300-1) with which it will communicate. 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 (e.g., subscriber device 300-1) with which it will communicate. This makes it possible to open an optical path connecting the subscriber devices 200-1 and 300-1, as shown in FIG. 7. [Prior art documents] [Non-patent literature]

[0006] [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]

[0007] Conventional communication networks generally consist of an access network (access NW), a metro network (metro NW), and a core network (core NW), with these networks connected in a hierarchical structure, as shown in Figure 8. In conventional communication networks, optical signals are converted into electrical signals at the boundary between the access network and the metro network, and at the boundary between the metro network and the core network, and then concentration and multiplexing are performed to carry a larger number of users and services over wider bandwidth optical paths.

[0008] In most cases, conventional optical access systems that connect subscriber devices (ONUs (Optical Network Units)) with accommodation devices (OLTs (Optical Line Terminals)) in accommodation buildings use single-fiber bidirectional transmission in which upstream and downstream optical signals are directional-multiplexed using WDM (Wavelength Division Multiplexing) to achieve cost-effectiveness. Here, as mentioned above, the optical path is temporarily terminated at the boundary between the access network and the metro network, and direct communication between subscriber devices under the same accommodation device is not assumed, so it is unlikely that the transmission wavelength of one subscriber device will be the receiving wavelength of another subscriber device.

[0009] Therefore, as shown in Figure 9, by using a wavelength demultiplexing unit with different wavelength ranges transmitted between each port, it is possible to realize a single product type of optical transceiver for single-fiber bidirectional transmission for a subscriber device. Figure 9 is a diagram showing an example of the configuration of a subscriber device 200 equipped with a conventional optical transceiver for single-fiber bidirectional transmission. Note that subscriber device 300 also includes the optical transceiver shown in Figure 9. The wavelength demultiplexing unit has transmission characteristics as shown in the balloon in Figure 9 and has the function of multiplexing or demultiplexing optical signals of different wavelengths across a certain wavelength. Figure 9 shows an example in which the short wavelength side is the transmission wavelength of the transmitting port (dashed line) and the long wavelength side is the transmission wavelength of the receiving port (solid line). Figure 10 is a diagram for explaining the issues with conventional optical communication systems.

[0010] When an optical path is opened using the optical transceiver shown in Figure 9 to communicatively connect the subscriber device 200-1 accommodated in the optical SW 500-1 and the subscriber device 300-1 accommodated in the optical SW 500-2 as shown in Figure 10, the optical signal transmitted by the subscriber device 200-1 is not transmitted by the wavelength demultiplexing unit in the optical transceiver of the subscriber device 300-1, and therefore the subscriber device 300-1 cannot receive the optical signal transmitted by the subscriber device 200-1.

[0011] Similarly, the subscriber device 200-1 cannot receive the optical signal transmitted by the subscriber device 300-1. The same applies when an optical path is opened to communicably connect the subscriber devices 200-2 and 200-3 accommodated in the optical SW 500-1, and the subscriber devices 200-2 and 200-3 cannot receive the optical signal from the opposite device.

[0012] While communication between opposing subscriber devices is possible if the wavelength transmission characteristics of the wavelength demultiplexing units in the optical transceivers of the opposing subscriber devices are made opposite to each other, this does not allow for the use of a single type of optical transceiver. Furthermore, communication is only possible between subscriber devices whose wavelength transmission characteristics of the wavelength demultiplexing units in the optical transceivers of the subscriber devices are opposite to each other. Thus, in the past, there was a problem in that it was not possible to achieve end-to-end optical connection between any subscriber devices using optical transceivers for a single type of subscriber device.

[0013] In view of the above circumstances, an object of the present invention is to provide a technique that can realize end-to-end optical connections between any number of subscriber devices using optical transceivers for a single type of subscriber device. [Means for solving the problem]

[0014] One aspect of the present invention is an optical communication system including a subscriber device that is optically connected to other subscriber devices end-to-end, and a management and control device that controls each subscriber device, wherein the subscriber device comprises an optical signal transmitting unit that transmits optical signals, an optical signal receiving unit that receives optical signals transmitted from the other subscriber devices, and an output function unit that outputs optical signals output by the optical signal transmitting unit to an optical transmission path regardless of wavelength, and outputs optical signals input from the optical transmission path to the optical signal receiving unit regardless of wavelength, and the management and control device assigns wavelengths so that the transmitting wavelength of the subscriber device becomes the receiving wavelength of the other subscriber devices, and the transmitting wavelength of the other subscriber devices becomes the receiving wavelength of the subscriber device.

[0015] One aspect of the present invention is an optical communication method in an optical communication system that optically connects a subscriber device to other subscriber devices that communicate with the subscriber device end-to-end and includes a management control device that controls each subscriber device, wherein the management control device assigns wavelengths so that the transmission wavelength of the subscriber device becomes the receiving wavelength of the other subscriber devices and the transmission wavelength of the other subscriber devices becomes the receiving wavelength of the subscriber device, the subscriber device outputs an optical signal to an optical transmission path regardless of wavelength, the other subscriber devices receive the optical signal transmitted from the subscriber device via the optical transmission path, and the other subscriber devices output the optical signal input from the optical transmission path to an optical signal receiving unit regardless of wavelength. [Effects of the Invention]

[0016] According to the present invention, it is possible to realize end-to-end optical connections between any number of subscriber devices using optical transceivers for a single type of subscriber device. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of an optical communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram showing a configuration example (part 1) of a subscriber device in an embodiment. [Figure 3] FIG. 2 is a diagram showing a second example of the configuration of a subscriber device in the embodiment. [Figure 4] FIG. 1 is a sequence diagram (part 1) showing a processing flow of an optical communication system according to an embodiment. [Figure 5] FIG. 2 is a sequence diagram (part 2) showing the flow of processing in the optical communication system according to the embodiment. [Figure 6] FIG. 1 is a diagram for explaining a method for opening an optical path in a conventional optical communication system. [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 illustrating the architecture of a conventional communication network. [Figure 9] FIG. 1 is a diagram showing an example of the configuration of a subscriber device equipped with a conventional optical transceiver for single-core bidirectional transmission. [Figure 10] FIG. 1 is a diagram for explaining a problem in a conventional optical communication system. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 is a diagram showing an example of the configuration of an optical communication system 1 according to an embodiment. The optical communication system 1 includes one or more subscriber devices 10 (e.g., subscriber devices 10-1 to 10-3), one or more subscriber devices 35 (e.g., subscriber devices 35-1 to 35-3), a management and control device 20, and a plurality of optical SWs 30-1 to 30-2. Optical transmission paths are used to connect the subscriber device 10 and the optical SW 30-1, the optical SW 30-1 and the optical SW 30-2, and the optical SW 30-2 and the subscriber device 35. The optical transmission paths are, for example, optical fibers. An optical communication NW 40 is configured between the optical SW 30-1 and the optical SW 30-2.

[0019] The subscriber device 10 includes an optical transceiver, and transmits and receives optical signals using the optical transceiver. The subscriber device 10 is, for example, an ONU installed in a subscriber's home.

[0020] The subscriber device 35 is a device that communicates with the subscriber device 10. The subscriber device 35 is equipped with an optical transceiver. The subscriber device 35 transmits and receives optical signals using the optical transceiver. The subscriber device 35 is, for example, an ONU installed in a subscriber's home.

[0021] The optical SWs 30-1 to 30-2 have M (M is an integer of 2 or more) first ports and N (N is an integer of 2 or more) second ports. In the embodiment, the numbers M and N are described as 4. An optical signal input to a port of the optical SWs 30-1 to 30-2 is output from another port. For example, an optical signal input to the first port of the optical SW 30 is output from the second port.

[0022] 1, a subscriber device 10 is connected to a first port of the optical SW30-1 via an optical transmission line, and an optical SW30-2 is connected to a second port of the optical SW30-1 via an optical transmission line. In the example shown in FIG. 1, a subscriber device 35 is connected to a first port of the optical SW30-2 via an optical transmission line, and an optical SW30-1 is connected to a second port of the optical SW30-2 via an optical transmission line.

[0023] The management control device 20 controls at least the subscriber devices 10 and 35 and the optical SW 30. Here, the control of the subscriber devices 10 and 35 includes, for example, allocating emission wavelengths to the subscriber devices 10 and 35, issuing instructions to stop light, and issuing instructions to change wavelengths. The control of the optical SW 30 includes, for example, switching connections between ports of the optical SW 30 and setting optical paths.

[0024] The management control device 20 includes a plurality of control units 21 (for example, control units 21-1 to 21-2) and a storage unit 22. Each control unit 21 controls each optical SW 30 and the subscriber device 10 or 35 accommodated in each optical SW 30. For example, the control unit 21-1 controls the optical SW 30-1 and the subscriber device 10 accommodated in the optical SW 30-1. For example, the control unit 21-2 controls the optical SW 30-2 and the subscriber device 35 accommodated in the optical SW 30-2.

[0025] The control unit 21-1 includes an optical SW control unit 23-1 and a customer equipment management control unit 24-1. The control unit 21-2 includes an optical SW control unit 23-2 and a customer equipment management control unit 24-2. The control units 21-1 and 21-2 perform similar processing except for the objects they control, so they will be described as the optical SW control unit 23 and the customer equipment management control unit 24 without distinction.

[0026] The optical SW control unit 23 sets and switches the connections between ports of the optical SW 30 and sets up optical paths. For example, in the optical communication system 1, when an optical path is opened end-to-end, the subscriber devices 10 and 35 have the configuration shown in Fig. 2 or 3. The configurations of the subscriber devices 10 and 35 will be described later.

[0027] As shown in FIG. 1, when an optical path is opened to communicably connect the subscriber device 10-1 accommodated in the optical SW 30-1 and the subscriber device 35-1 accommodated in the optical SW 30-2, the management control device 20 sets the transmission wavelength (λ m ) is the receiving wavelength of the subscriber device 35-1, and the transmitting wavelength (λ n ) is assigned to the end-end optical path as the receiving wavelength of the subscriber device 10-1.

[0028] Similarly, when an optical path is opened to communicably connect the subscriber device 10-2 and the subscriber device 10-3 accommodated in the optical SW 30-1, the management control device 20 sets the transmission wavelength (λ h ) is the receiving wavelength of the subscriber device 10-3, and the transmitting wavelength (λ k ) is assigned to the end-end optical path as the receiving wavelength of the subscriber device 10-2.

[0029] When a new subscriber device is connected to the optical SW 30, the subscriber device management and control unit 24 identifies to which port of the optical SW 30 the newly connected subscriber device is connected, and performs processing to open an optical path, such as specifying a wavelength to the subscriber device. Note that the optical path opening processing in the subscriber device management and control unit 24 is the same as in the past, and therefore a description thereof will be omitted. The functions of the optical SW control unit 23 and the subscriber device management and control unit 24 may be realized by one or more processors executing programs.

[0030] The memory unit 22 stores subscriber information. The subscriber information is information relating to the subscriber devices 10 and 35. The subscriber information includes, for example, information indicating to which port of the optical SW 30 the subscriber devices 10 and 35 are connected, and information on wavelengths assigned to the subscriber devices 10 and 35.

[0031] 2 is a diagram showing a configuration example (part 1) of the subscriber devices 10 and 35 in the embodiment. Since the subscriber devices 10 and 35 have the same configuration, the subscriber device 10 will be described as an example in FIG. 2. The subscriber device 10 includes an optical transceiver 11. The optical transceiver 11 includes an optical signal transmitter 12, a circulator 13, and an optical signal receiver 14.

[0032] The optical signal transmitting unit 12 transmits an optical signal having a wavelength assigned by the management control device 20 via a circulator 13 .

[0033] The circulator 13 has a first port 131, a second port 132, and a third port 133. The first port 131 of the circulator 13 is connected to the optical signal transmitter 12. The second port 132 of the circulator 13 is connected to the optical transmission path. The third port 133 of the circulator 13 is connected to the optical signal receiver 14. An optical signal input to the first port 131 is output from the second port 132. An optical signal input to the second port 132 is output from the third port 133.

[0034] In this way, the circulator 13 has directionality and port selectivity but does not have wavelength selectivity. Therefore, the optical signal output by the optical signal transmitter 12 can be output to the optical transmission line regardless of the wavelength of the optical signal. Furthermore, the circulator 13 can transfer the optical signal input from the optical transmission line to the optical signal receiver 14 regardless of the wavelength of the optical signal. Furthermore, the directionality and port selectivity of the circulator 13 can prevent the optical signal input from the optical transmission line from being input to the optical signal transmitter 12. The circulator 13 is one aspect of an output function unit.

[0035] The optical signal receiving unit 14 receives the optical signal transferred from the circulator 13. For example, the optical signal receiving unit 14 is a PD (Photo Diode) or the like.

[0036] FIG. 3 is a diagram showing a second example of the configuration of the subscriber devices 10 and 35 according to the embodiment. Since the subscriber devices 10 and 35 have the same configuration, FIG. 3 will explain the subscriber device 10 as an example. The subscriber device 10 includes an optical transceiver 11. The optical transceiver 11 is made up of an optical signal transmitter 12, an optical signal receiver 14, an isolator 15, an optical multiplexer / demultiplexer 16, and a wavelength tunable selector 17. The same reference numerals are used for the components explained in FIG. 2, and explanations thereof will be omitted.

[0037] The isolator 15 is a signal isolator that has directionality and transmits optical signals output from the optical signal transmitting unit 12 to the optical multiplexing / demultiplexing unit 16, while blocking the input of optical signals output from the optical multiplexing / demultiplexing unit 16. In other words, the isolator 15 has the function of transmitting optical signals in a first direction from the optical signal transmitting unit 12 to the optical multiplexing / demultiplexing unit 16, and blocking optical signals in a second direction from the optical multiplexing / demultiplexing unit 16 to the optical signal transmitting unit 12. Note that if the optical signal transmitting unit 12 includes an isolator function, the subscriber device 10 does not need to include the isolator 15.

[0038] The optical multiplexing / demultiplexing unit 16 has the function of multiplexing or branching input optical signals. For example, the optical multiplexing / demultiplexing unit 16 multiplexes optical signals input from a first port to which the isolator 15 is connected and a second port to which the wavelength tunable selection unit 17 is connected, and outputs the multiplexed signal to a third port to which an optical transmission line is connected, and branches the optical signal input from the third port, and outputs the branched signal to the first and second ports. The optical multiplexing / demultiplexing unit 16 is one aspect of an output function unit.

[0039] By including the optical multiplexing / demultiplexing unit 16, the subscriber device 10 can output the optical signal output by the optical signal transmitting unit 12 to the optical transmission line regardless of the wavelength of the optical signal. Furthermore, by including the optical multiplexing / demultiplexing unit 16, the subscriber device 10 can transfer the optical signal input from the optical transmission line to the wavelength tunable selecting unit 17 regardless of the wavelength of the optical signal. The optical multiplexing / demultiplexing unit 16 can be an optical coupler configured by optical fiber, PLC (Planar Lightwave Circuit), or the like.

[0040] The tunable wavelength selection unit 17 transmits only optical signals having wavelengths within a set wavelength range. In the case of single-fiber bidirectional transmission, the wavelength of the optical signal output by the optical signal transmission unit 12 differs from the wavelength of the optical signal received by the optical signal reception unit 14. Therefore, by providing the tunable wavelength selection unit 17, it is possible to block the optical signal output from the optical signal transmission unit 12 that returns to the optical transceiver 11 due to reflections in the optical transmission path, thereby preventing degradation of reception characteristics.

[0041] Fig. 4 is a sequence diagram (part 1) showing the processing flow of the optical communication system 1 in the embodiment. In the explanation of Fig. 4, the case where the subscriber devices 10 and 35 have the configuration shown in Fig. 2 will be explained. Furthermore, at the start of the processing of Fig. 4, it is assumed that the connection relationship between the ports of the optical SW30-1 and 30-2 is set to the connection relationship shown in Fig. 1.

[0042] The optical signal transmitter 12 of the subscriber device 10 outputs an optical signal (step S101). The optical signal output by the optical signal transmitter 12 is input to the first port 131 of the circulator 13. The optical signal input to the first port 131 of the circulator 13 is output to the optical transmission line from the second port 132. The optical signal output from the subscriber device 10 in this manner is input to the first port of the optical SW30-1 via the optical transmission line.

[0043] The optical signal input to the first port of optical SW30-1 is output from the second port connected to the first port. The optical signal output from the second port of optical SW30-1 is input to the second port of optical SW30-2 (step S102). The optical signal input to the second port of optical SW30-2 is output from the first port connected to the second port. The optical signal output from the first port of optical SW30-2 is input to the subscriber device 35 (step S103).

[0044] The optical signal input to the second port of the circulator of the subscriber device 35 is output to the optical signal receiving unit from the third port of the circulator (step S104). The optical signal receiving unit of the subscriber device 35 receives the input optical signal (step S105).

[0045] Fig. 5 is a sequence diagram (part 2) showing the processing flow of the optical communication system 1 in the embodiment. In the explanation of Fig. 5, the case where the subscriber devices 10 and 35 have the configuration shown in Fig. 3 will be explained. Furthermore, at the start of the processing of Fig. 5, it is assumed that the connection relationship between the ports of the optical SW30-1 and 30-2 is set to the connection relationship shown in Fig. 1.

[0046] The optical signal transmitting unit 12 of the subscriber device 10 outputs an optical signal (step S201). The optical signal output by the optical signal transmitting unit 12 is input to the optical multiplexing / demultiplexing unit 16 via the isolator 15. The optical signals input to the optical multiplexing / demultiplexing unit 16 are multiplexed and output to the optical transmission line. The optical signal output from the subscriber device 10 in this manner is input to the first port of the optical SW30-1 via the optical transmission line.

[0047] The optical signal input to the first port of optical SW30-1 is output from the second port connected to the first port. The optical signal output from the second port of optical SW30-1 is input to the second port of optical SW30-2 (step S202). The optical signal input to the second port of optical SW30-2 is output from the first port connected to the second port. The optical signal output from the first port of optical SW30-2 is input to the subscriber device 35 (step S203).

[0048] The optical signal input to the optical multiplexing / demultiplexing unit of the subscriber device 35 is branched and output to the isolator and the wavelength tunable selection unit (step S204). The optical signal output to the isolator is blocked. The wavelength tunable selection unit transmits an optical signal having a wavelength within the set wavelength range (step S205). If the optical signal input to the wavelength tunable selection unit has a wavelength outside the wavelength range set in the wavelength tunable selection unit, the wavelength tunable selection unit does not transmit the input optical signal. The optical signal receiving unit of the subscriber device 35 receives the input optical signal (step S206).

[0049] The optical communication system 1 configured as described above enables end-to-end optical connections between any two or more subscriber devices using optical transceivers for a single type of subscriber device. Specifically, in the optical communication system 1, the subscriber devices 10 and 35 installed at the end and end serve as optical transceivers for the subscriber device, and each has the function of outputting an optical signal output from its optical signal transmitter to an optical transmission line regardless of wavelength, and forwarding an optical signal input from the optical transmission line to its optical signal receiver regardless of wavelength. Furthermore, the management and control device 20 provided in the optical communication system 1 assigns wavelengths so that the transmission wavelength of the subscriber device 10 matches the reception wavelength of the subscriber device 35, and vice versa. This enables end-to-end optical connections between any two or more subscriber devices using optical transceivers for a single type of subscriber device.

[0050] In the optical communication system 1, the subscriber devices 10 and 35 installed end-to-end each have a circulator as an optical transceiver for the subscriber device, as shown in Figure 2. By providing each of the subscriber devices 10 and 35 with a circulator in this way, the circulator's directivity and port selectivity enable the optical signal output from the optical signal transmitter to be output to the optical transmission line regardless of the wavelength of the optical signal, and the optical signal input from the optical transmission line to the optical signal receiver regardless of the wavelength of the optical signal. This makes it possible to achieve end-to-end optical connections between any subscriber devices using a single type of optical transceiver for the subscriber device.

[0051] In the optical communication system 1, the subscriber devices 10 and 35 installed end-to-end each include an optical multiplexer / demultiplexer, an isolator, and a wavelength tunable selector as a subscriber device optical transceiver, as shown in Figure 3. As such, by each of the subscriber devices 10 and 35 being equipped with an optical multiplexer / demultiplexer, an isolator, and a wavelength tunable selector, the optical signal output from the optical signal transmitter can be output to the optical transmission line regardless of the wavelength of the optical signal, and the optical signal input from the optical transmission line can be forwarded to the optical signal receiver regardless of the wavelength of the optical signal. This makes it possible to realize end-to-end optical connections between any subscriber devices using a single type of subscriber device optical transceiver.

[0052] Some of the functional units of the subscriber devices 10, 35 and the management control device 20 in the above-described embodiments may be realized by a computer. In this case, a program for realizing 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" includes hardware such as an OS (Operating System) and peripheral devices.

[0053] Furthermore, "computer-readable recording media" refers to portable media such as flexible disks, optical magnetic disks, ROMs (Read Only Memory), 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 communication lines like telephone lines, or devices that store programs for a fixed period of time, such as volatile memory within 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 (Field Programmable Gate Arrays).

[0054] 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]

[0055] The present invention can be applied to an optical communication system that sets up an optical path end-to-end. [Explanation of symbols]

[0056] 10, 35... subscriber device, 11... optical transceiver, 12... optical signal transmitting unit, 13... circulator, 14... optical signal receiving unit, 15... isolator, 16... optical multiplexing / demultiplexing unit, 17... wavelength tunable selecting unit, 20... management control device, 21-1, 21-2... control unit, 22... memory unit, 23-1, 23-2... optical SW control unit, 24-1, 24-2... subscriber device management control unit, 30-1, 30-2... optical SW, 40... optical communication NW

Claims

1. An optical communication system including a subscriber device that is optically connected to other subscriber devices in an end-to-end manner, and a management control device that controls each subscriber device, The subscriber device an optical signal transmitting unit that transmits an optical signal; an optical signal receiving unit for receiving an optical signal transmitted from the other subscriber device; an output function unit that outputs an optical signal output from the optical signal transmitting unit to an optical transmission line regardless of wavelength, and outputs an optical signal input from the optical transmission line to the optical signal receiving unit regardless of wavelength; Equipped with The management control device assigning wavelengths so that the transmission wavelength of the subscriber device becomes the reception wavelength of the other subscriber device, and the transmission wavelength of the other subscriber device becomes the reception wavelength of the subscriber device; the output function unit is an optical multiplexing / demultiplexing unit that multiplexes or demultiplexes input optical signals, the optical multiplexing / demultiplexing unit has a first port, a second port, and a third port; the first port is connected to the optical signal transmitting unit; the second port is connected to the optical signal receiving unit; the third port is connected to the optical transmission line; the optical multiplexing / demultiplexing unit multiplexes the optical signal input to the first port and the optical signal input to the second port, and outputs the multiplexed signal to the optical transmission path connected to the third port, and branches the optical signal input to the third port, and outputs the branched signal to the optical signal transmitting unit connected to the first port and the optical signal receiving unit connected to the second port; The subscriber device further comprising a signal isolator between the optical signal transmission unit and the optical multiplexing / demultiplexing unit, which transmits an optical signal in a first direction from the optical signal transmission unit to the optical multiplexing / demultiplexing unit and blocks an optical signal in a second direction from the optical multiplexing / demultiplexing unit to the optical signal transmission unit; Optical communication system.

2. The subscriber device a wavelength variable selection unit that transmits an optical signal having a wavelength within a preset wavelength range, between the optical signal receiving unit and the optical multiplexing / demultiplexing unit; 2. The optical communication system according to claim 1.

3. An optical communication method in an optical communication system including a management and control device that optically connects a subscriber device and another subscriber device that communicates with the subscriber device in an end-to-end manner and controls each subscriber device, the management control device assigns wavelengths so that the transmission wavelength of the subscriber device becomes the reception wavelength of the other subscriber device, and the transmission wavelength of the other subscriber device becomes the reception wavelength of the subscriber device; the subscriber device outputs the optical signal output by the optical signal transmitter to the optical transmission line regardless of wavelength by the output function unit; the other subscriber device receives the optical signal transmitted from the subscriber device via the optical transmission path; the subscriber device outputs the optical signal input from the optical transmission line to an optical signal receiving unit regardless of wavelength, the output function unit is an optical multiplexing / demultiplexing unit that multiplexes or demultiplexes an input optical signal, the optical multiplexing / demultiplexing unit has a first port, a second port, and a third port, the first port is connected to the optical signal transmitting unit; the second port is connected to the optical signal receiving unit; the third port is connected to the optical transmission line; the optical multiplexing / demultiplexing unit multiplexes the optical signal input to the first port and the optical signal input to the second port, and outputs the multiplexed signal to the optical transmission path connected to the third port, and branches the optical signal input to the third port, and outputs the branched signal to the optical signal transmitting unit connected to the first port and the optical signal receiving unit connected to the second port, the subscriber device: a signal isolator is provided between the optical signal transmission unit and the optical multiplexing / demultiplexing unit to transmit an optical signal in a first direction from the optical signal transmission unit to the optical multiplexing / demultiplexing unit and to block an optical signal in a second direction from the optical multiplexing / demultiplexing unit to the optical signal transmission unit; Optical communication method.

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