Optical communication system, optical transmitting / receiving device, and optical communication method

Abstract

According to the present invention, an optical switch receives, from a first port, an input of an optical signal transmitted by a first optical communication device, and outputs an optical signal from a second port connected to a first optical transmission line included in an optical pathway in which a light path is set between the first optical communication device and a second optical communication device. An optical branching unit causes a portion of an optical signal transmitted through the first optical transmission line to branch and outputs the branched optical signal to a second optical transmission line. An optical transceiver has a receiving unit, a transmitting unit, and a light blocking unit. The receiving unit receives an input of the optical signal branched by the optical branching unit from the second optical transmission line and acquires, from the received optical signal, a signal of a destination different from the second optical communication device. The transmitting unit uses light emitted by a light source and generates an optical signal. The light blocking unit prevents the light from the light source from entering the second optical transmission line.

Description

[Technical Field]

[0001] The present invention relates to an optical communication system, an optical transmitting / receiving device, and an optical communication method. [Background technology]

[0002] An optical communication system relays optical signals between subscriber devices. FIG. 5 is a diagram showing an example of the configuration of a conventional optical communication system. Subscriber devices are connected via one or more optical switches (SWs). The optical SWs are also connected via an optical communication network (NW). FIG. 5 shows an example of two optical SWs. The optical SW is an optical switching device that outputs signal light input from each port to another port. The other ports from which the signal light is output are connection ports that are connected to the port that input the signal light. Specifically, the optical SW has multiple first ports and multiple second ports. Each first port is connected to a subscriber device via an optical fiber transmission line. Each second port is connected to a control unit or an optical communication NW via an optical fiber transmission line. The optical SW outputs an optical signal input from the first port to a second port with which it is connected, and outputs an optical signal input from the second port from the first port with which it is connected. The connection relationship between ports can be freely set and changed.

[0003] In the following, the two optical SWs will be referred to as optical SW #1 and optical SW #2, and the subscriber device connected to optical SW #n (n is an integer greater than or equal to 1 and less than or equal to N) will be referred to as subscriber device #kn-n (kn is an integer greater than or equal to 1).

[0004] Using Figure 5, we will explain an optical path opening method for connecting subscriber device #k1-1 to its communication partner subscriber device #k2-2 via the optical fiber transmission line and optical SW, taking the case where k1 = 1 and k2 = 1 as an example. When initially connecting subscriber device #1-1, the optical SW control unit of the control unit sets up a port-to-port connection of the optical SW #1 so that subscriber device #1-1 communicates with the subscriber device management and control unit. At this time, information required for registering and authenticating subscriber device #1-1 is transmitted and received between subscriber device #1-1 and the subscriber device management and control unit, and instructions on the emission wavelength to be used are sent from the subscriber device management and control unit to subscriber device #1-1. An auxiliary management and control channel (AMCC) can be used as a channel for transmitting and receiving such management and control information.

[0005] As soon as the subscriber device management and control unit completes the registration and authentication of subscriber device #1-1 and the wavelength setting, the optical switch control unit changes the port connection settings of optical switch #1. Specifically, the optical switch control unit changes the port connection settings so that the optical signal transmitted from subscriber device #1-1 is forwarded to the communicating subscriber device #1-2. This opens an optical path that directly connects subscriber device #1-1 and subscriber device #1-2. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Takuya Kanai and six others, "Photonic Gateway Supporting All-Photonics Network," Institute of Electronics, Information and Communication Engineers General Conference, B-8-20, p.141, March 2021 Summary of the Invention [Problem to be solved by the invention]

[0007] In conventional optical communication systems, once an optical path is established, there is no control channel for transmitting control signals from the subscriber device to the control unit, so the subscriber device cannot transmit requests to the control unit.

[0008] In view of the above circumstances, the present invention aims to provide an optical communication system, an optical transmitting / receiving device, and an optical communication method that are capable of transmitting and receiving signals using an optical path between a communication partner device and another device, while transmitting signals to another device other than the communication partner device. [Means for solving the problem]

[0009] An optical communication system of one embodiment of the present invention comprises an optical switch that inputs an optical signal transmitted by a first optical communication device from a first port and outputs the optical signal from a second port connected to a first optical transmission line included in an optical route in which an optical path is set between the first optical communication device and a second optical communication device; an optical branching unit that branches a portion of the optical signal transmitted through the first optical transmission line and outputs the branched optical signal to a second optical transmission line; and an optical transmitter / receiver that inputs the optical signal branched by the optical branching unit from the second optical transmission line, wherein the optical transmitter / receiver comprises a receiving unit that obtains a signal having a destination other than that of the second optical communication device from the optical signal input from the second optical transmission line, a transmitting unit that generates an optical signal using light emitted by a light source, and a blocking unit that prevents light from the light source from being input to the second optical transmission line.

[0010] An optical transceiver according to one embodiment of the present invention comprises: a receiving unit that receives an optical signal from a second optical transmission line obtained by branching a portion of an optical signal transmitted from the first optical communication device using an optical branching unit provided in a first optical transmission line included in an optical path in which an optical path is set between a first optical communication device and a second optical communication device; a transmitting unit that generates an optical signal using light emitted by a light source; and a blocking unit that prevents light from the light source from being input to the second optical transmission line.

[0011] An optical transceiver according to one embodiment of the present invention comprises a receiving unit that receives an optical signal transmitted from a destination device, which is a destination optical communication device, via an optical transmission path, and a transmitting unit that generates an optical signal carrying a first signal destined for the destination device and a second signal destined for a different destination device, and outputs the optical signal to the optical transmission path.

[0012] An optical communication method of one embodiment of the present invention includes a switching step in which an optical switch inputs an optical signal transmitted by a first optical communication device from a first port and outputs the optical signal from a second port connected to a first optical transmission line included in an optical route in which an optical path between the first optical communication device and a second optical communication device is set; a branching step in which an optical branching unit branches a portion of the optical signal transmitted on the first optical transmission line and outputs the branched optical signal to a second optical transmission line; a receiving step in which a receiving unit of an optical transmitting / receiving device inputs the optical signal branched by the optical branching unit from the second optical transmission line and obtains a signal having a destination other than that of the second optical communication device from the input optical signal; and a blocking step in which a blocking unit of the optical transmitting / receiving device prevents light from a light source used by a transmitting unit of the optical transmitting / receiving device to transmit an optical signal from being input to the second optical transmission line.

[0013] An optical communication method of one embodiment of the present invention includes a receiving step in which a receiving unit inputs an optical signal from a second optical transmission line obtained by branching a portion of an optical signal transmitted from the first optical communication device using an optical branching unit provided in a first optical transmission line included in an optical route in which an optical path is set between a first optical communication device and a second optical communication device, and obtains a signal having a destination other than that of the second optical communication device from the input optical signal; and a blocking step in which a blocking unit prevents light from a light source used by a transmitting unit to transmit an optical signal from being input to the second optical transmission line.

[0014] An optical communication method of one embodiment of the present invention includes a receiving step in which a receiving unit inputs an optical signal transmitted by a communication destination device, which is a communication destination optical communication device, from an optical transmission path and receives the input optical signal, and a transmitting step in which a transmitting unit generates an optical signal carrying a first signal destined for the communication destination device and a second signal destined for a different destination device, and outputs the optical signal to the optical transmission path. [Effects of the Invention]

[0015] According to the present invention, it is possible to transmit a signal to a device other than the communication partner device while transmitting and receiving a signal using an optical path between the communication partner device and the device. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a diagram illustrating an example of the configuration of an optical communication system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating a configuration example of an optical transceiver according to the embodiment. [Figure 3] FIG. 2 is a diagram illustrating a configuration example of an optical transceiver according to the embodiment. [Figure 4] 2 is a diagram showing the connection relationship between optical transceivers in the optical communication system according to the embodiment. FIG. [Figure 5] FIG. 1 is a diagram illustrating an example of the configuration of a conventional optical communication system. [Figure 6] FIG. 1 is a diagram illustrating an example of the configuration of an optical communication system. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the same parts in the drawings are designated by the same reference numerals, and the description thereof will be omitted.

[0018] In the conventional optical communication system configuration shown in Figure 5, once an optical path is opened, the subscriber device cannot transmit a request to the control unit. Therefore, the optical communication system configuration shown in Figure 6 can be considered. In the optical communication system shown in Figure 6, an optical branching unit is installed in the transmission path between the optical SW #1 and the optical communication NW. The optical branching unit branches the power of the optical signal output from the subscriber device #k1-1 and outputs the branched optical signal to the control unit. With this configuration, when the subscriber device outputs a control signal to transmit a request to the control unit, the control signal is input to the control unit. The control signal receiving unit of the control unit receives the control signal included in the optical signal branched by the optical branching unit.

[0019] However, when the optical transceiver (TRx) in the control signal receiving unit emits light, that light passes through the optical branching unit and merges with the main signal, potentially causing interference. Specifically, the light carrying the main signal from subscriber unit #1-2 to subscriber unit #1-1 merges with the light emitted from the optical transceiver in the control signal receiving unit at the optical branching unit. When the wavelength of the light carrying the main signal is the same as the wavelength of the light from the optical transceiver, interference occurs regardless of the frequency of the signal carrying the main signal. As a result, subscriber unit #1-1 cannot correctly receive the main signal. Therefore, it is desirable to transmit a signal to a control unit other than the communicating subscriber unit while reducing the impact on the signal transmitted and received using the optical path between the communicating subscriber unit and the communicating subscriber unit.

[0020] FIG. 1 is a diagram showing an example of the configuration of an optical communication system 1 according to an embodiment of the present invention. The optical communication system 1 includes N (N is an integer equal to or greater than 1) optical SWs 10, a subscriber device 20, and a control system 30. The optical SWs 10 may be the conventional optical SWs shown in FIG. 5. FIG. 5 shows an example where N=2. The nth (n is an integer equal to or greater than 1 and equal to or less than N) optical SW 10 is referred to as optical SW10-n. The control system 30 includes one or more control units 31. In this embodiment, the control unit 31 connected to the optical SW 10-n is referred to as control unit 31-n. Note that one control unit 31 may be connected to two or more optical SWs 10.

[0021] The optical SW10 has a plurality of first ports 11 and a plurality of second ports 12. The first ports 11 are connected to the subscriber device 20 via an optical fiber transmission line 41. The second ports 12 are connected to the control unit 31 or the optical communication network (NW) 60 via an optical fiber transmission line 42. The optical SW10 outputs an optical signal input from the first port 11 to the second port 12 with which a connection relationship has been established, and outputs an optical signal input from the second port 12 from the first port 11 with which a connection relationship has been established. The connection relationship between the ports can be changed and set as desired.

[0022] The subscriber device 20 transmits and receives optical signals to and from another subscriber device 20, which is a communication partner. The subscriber device 20 includes an optical transceiver (TRx) 21. The optical transceiver 21 is an AMCC (Auxiliary Management and Control Channel)-compatible optical TRx. An AMCC-compatible TRx has the capability of transmitting and receiving control signals using AMCC. In the electrical domain, the AMCC signal and the main signal use different frequencies, while in the optical domain, the AMCC signal and the main signal use the same wavelength. For example, the optical transceiver 21 combines an electrical main signal with an electrical AMCC signal and converts the combined signal into an optical signal to generate a high-speed main signal on which a low-frequency AMCC signal is superimposed. The optical transceiver 21 may generate an optical signal that carries only the main signal without a control signal superimposed thereon, or it may generate an optical signal that carries no main signal but a control signal. The optical transceiver 21 outputs the generated optical signal to the optical fiber transmission line 41 and receives the optical signal output by the optical SW10 to the optical fiber transmission line 41. Hereinafter, the knth (kn is an integer equal to or greater than 1) subscriber device 20 connected to the optical SW10-n will be referred to as subscriber device 20-kn-n, and the optical transceiver 21 included in the subscriber device 20-kn-n will be referred to as optical transceiver 21-n.

[0023] An optical fiber transmission line 42 connecting the optical SW10 and the optical communication network 60 is provided with an optical branching unit 50. The optical branching unit 50 is connected to the control unit 31 by the optical fiber transmission line 43. The optical branching unit 50 branches a part of the optical signal transmitted through the optical fiber transmission line 42 and outputs it to the optical fiber transmission line 43. The optical branching unit 50 is, for example, an optical coupler. Hereinafter, the optical fiber transmission line 42 connected to the optical SW10-n will be referred to as the optical fiber transmission line 42-n, the optical branching unit 50 provided in the optical fiber transmission line 42-n will be referred to as the optical branching unit 50-n, and the optical fiber transmission line 43 connected to the optical branching unit 50-n will be referred to as the optical fiber transmission line 43-n.

[0024] The control unit 31 of the control system 30 has a subscriber device management and control unit 32, an optical SW control unit 33, and a control signal receiving unit 34. The subscriber device management and control unit 32 is connected to the second port 12 of the optical SW 10 via an optical fiber transmission line 42. The subscriber device management and control unit 32 transmits and receives information necessary for registering and authenticating the subscriber device 20 before the subscriber device 20 starts optical communication with the destination device. The subscriber device management and control unit 32 also determines the optical path from the subscriber device 20 to the destination device, and allocates resources such as wavelengths to the subscriber device 20 to use for communication with the destination device.

[0025] The optical SW control unit 33 determines the inter-port connection of the optical SW 10 according to the optical path assigned to the subscriber device 20 by the subscriber device management control unit 32. The inter-port connection is the connection relationship of which first port 11 an optical signal input from is connected to which second port 12, and which second port 12 an optical signal input from is output to the other first port 11. The optical SW control unit 33 controls the optical SW 10 to switch the optical signal according to the determined inter-port connection.

[0026] The control signal receiving unit 34 is connected to the optical branching unit 50 via an optical fiber transmission line 43. The control signal receiving unit 34 includes an optical transceiver (TRx) 35. The optical transceiver 35 is an AMCC-compatible TR. The optical transceiver 35 receives the optical signal branched by the optical branching unit 50 and extracts the control signal of the AMCC signal from the received optical signal. The control signal receiving unit 34 performs predetermined processing based on the control signal extracted by the optical transceiver 35.

[0027] Next, an example of the configuration of the optical transceiver 35 will be described. FIG. 2 is a diagram showing an example of the configuration of a single-core optical transceiver 70. FIG. 2 shows only functional units related to this embodiment. The optical transceiver 70 is used as the optical transceiver 35. The optical transceiver 70 includes a port 71, a demultiplexer 72, a receiver (Rx) 73, a transmitter (Tx) 74, and a power supply controller 76. The port 71 receives an optical signal from the optical fiber transmission line 43 and outputs it to the demultiplexer 72. The demultiplexer 72 then outputs the optical signal to the optical fiber transmission line 43. The demultiplexer 72 demultiplexes the optical signal by wavelength. The demultiplexer 72 outputs the optical signal received by the port 71 from the optical fiber transmission line 43 to the receiver 73, and outputs the optical signal output by the transmitter 74 from the port 71 to the optical fiber transmission line 43. The receiver 73 receives the optical signal demultiplexed by the demultiplexer 72 and converts it into an electrical signal. A wavelength filter that passes an optical signal of a wavelength received by the receiver 73 may be provided between the receiver 73 and the separator 72. The transmitter 74 has a light source 75. The transmitter 74 generates an optical signal by modulating light emitted by the light source 75 with an electrical signal. The transmitter 74 outputs the generated optical signal to the separator 72. The light source 75 may be a wavelength-tunable light source. The power supply controller 76 controls whether or not to supply current to the light source 75.

[0028] FIG. 3 is a diagram showing an example of the configuration of a dual-core optical transceiver 80. FIG. 3 shows only functional units related to this embodiment. The optical transceiver 80 is used as the optical transceiver 35. In FIG. 3, the same components as those of the optical transceiver 70 shown in FIG. 2 are designated by the same reference numerals, and their description will be omitted. The optical transceiver 80 includes an input port 81, an output port 82, a receiver 73, and a transmitter 74. The input port 81 receives an optical signal from the optical fiber transmission line 43 and outputs it to the receiver 73. A wavelength filter may be provided between the input port 81 and the receiver 73 to pass an optical signal of the wavelength received by the receiver 73. The output port 82 outputs the optical signal output by the transmitter 74 to the optical fiber transmission line 43.

[0029] Conventional optical transceivers can receive optical signals in a link-up state, in which a signal transmitted from an optical communication device into which the optical transceiver is inserted reaches another optical communication device into which another optical transceiver is inserted, which is the communication destination. The optical transceiver 35 of this embodiment can receive optical signals regardless of whether the optical communication device into which the optical transceiver is inserted is in a link-up state. In other words, the optical transceiver 35 can receive optical signals even if the optical signal it transmitted has not yet reached the other optical transceiver.

[0030] The optical transceiver 21 included in the subscriber device 20 may also have a configuration similar to the optical transceiver 70 shown in FIG. 2 or the optical transceiver 80 shown in FIG. 3. By using a tunable light source as the light source 75, the transmitter 74 can transmit an optical signal with a wavelength assigned by the subscriber device management and control unit 32. The optical transceiver 21 is an optical transceiver that can transmit control signals regardless of whether or not it has received control signals from other optical transceivers. The optical transceiver 21 can transmit control signals to the optical transceiver 35 even when it cannot receive signals from the optical transceiver 35.

[0031] 4 is a diagram showing the connection relationship between the optical transceiver 21-n of the subscriber unit 20-kn-n shown in FIG. 1, the optical transceiver 21-m of the subscriber unit 20-km-m (m is an integer between 1 and N, and km is an integer greater than or equal to 1), and the optical transceiver 35 provided in the control signal receiving unit 34 of the control unit 31-n. Note that the control signal C and main signal M shown in FIG. 4 indicate the relationship between the signal source and destination, and do not represent optical signals. Below, the operation of the optical communication system 1 will be explained using FIG. 1 and FIG. 4, taking the case where n=1 and m=2 as an example.

[0032] The optical communication system 1 opens an optical path P between the subscriber device 20-k1-1 and the subscriber device 20-k2-2 using a procedure similar to that of the conventional technology. That is, the optical SW control unit 33 of the control unit 31-1 sets up a port-to-port connection in the optical SW 10-1 between the first port 11 connected to the subscriber device #k1-1 and the second port 12 connected to the subscriber device management and control unit 32. The subscriber device management and control unit 32 performs registration and authentication based on information received from the subscriber device 20-k1-1. Furthermore, the subscriber device management and control unit 32 determines an optical path between the subscriber device 20-k1-1 and the subscriber device 20-k2-2, the communication destination notified by the subscriber device 20-k1-1, and assigns a wavelength to be used. The subscriber device management and control unit 32 notifies the subscriber device 20-k1-1 of the assigned wavelength. The optical SW control unit 33 changes the setting of the optical SW 10-1 so as to perform a port-to-port connection according to the optical path determined by the subscriber device management and control unit 32. This allows an optical path P that directly connects subscriber device #k1-1 and subscriber device #k2-2 to be opened. The optical path of the optical path P includes an optical fiber transmission line 41-1, an optical SW10-1, an optical fiber transmission line 42-1, an optical communication NW 60, an optical fiber transmission line 42-2, an optical SW10-2, and an optical fiber transmission line 41-2.

[0033] The optical transceiver 21-1 of the subscriber device 20-k1-1 and the optical transceiver 21-2 of the subscriber device 20-k2-2 transmit and receive optical signals via the optical path P. The optical transceiver 21-1 converts an electrical main signal M addressed to the subscriber device 20-k2-2 into an optical signal and outputs it to the optical path P. When transmitting a control signal C to the control unit 31-n, the optical transceiver 21-1 generates an optical signal by superimposing the electrical main signal M addressed to the subscriber device 20-k2-2 on the electrical control signal C addressed to the control unit 31-n, and outputs it to the optical path P.

[0034] An optical branching unit 50 provided in an optical fiber transmission line 42-1 constituting the optical path of the optical path P branches an optical signal transmitted through the optical fiber transmission line 42-1 and outputs the branched optical signal to an optical fiber transmission line 43-1. An optical transceiver 35 included in a control signal receiving unit 34 of the control unit 31-1 receives an optical signal from the optical fiber transmission line 43-1. A receiver 73 of the optical transceiver 35 converts the received optical signal into an electrical signal and obtains a control signal C from the converted electrical signal.

[0035] On the other hand, the optical transceiver 21-2 of the subscriber device 20-k2-2 inputs an optical signal that has propagated along the optical path P. The optical transceiver 21-2 converts the input optical signal into an electrical signal and obtains the main signal M from the converted electrical signal. The optical transceiver 21-2 of the subscriber device 20-k2-2 also converts the electrical main signal M addressed to the subscriber device 20-k1-1 into an optical signal and outputs it to the optical path P. The optical transceiver 21-1 of the subscriber device 20-k1-1 inputs the optical signal that has propagated along the optical path P. The optical transceiver 21-1 converts the input optical signal into an electrical signal and obtains the main signal M from the converted electrical signal.

[0036] The optical transceiver 35 included in the control signal receiver 34 of the control unit 31-1 prevents light emitted from the light source 75 of the transmitter 74 from being input to the optical fiber transmission line 43. For example, if the transmitter 74 is the optical transceiver 70 shown in FIG. 2, the power supply controller 76 cuts off the current supply to the light source 75. The cutoff of the current supply turns off the light emission of the light source 75. The light source 75 may be kept off at all times. By turning off the light emission of the light source 75, interference between the signal light of the main signal M transmitted by the optical transceiver 21-2 and the light emission of the light source 75 of the optical transceiver 35 is avoided. Furthermore, if the optical transceiver 35 is a dual-core optical transceiver 80 with separate input and output optical ports as shown in FIG. 3, the output port 82 from which the control signal receiver 34 outputs the optical signal may be left open. Specifically, the output port 82 is not connected to the optical fiber transmission line 43-1. By opening the output port 82, interference between the signal light of the main signal M transmitted by the optical transceiver 21-2 and the light emitted from the optical transceiver 35 can be avoided.

[0037] When transmitting a control signal from the optical transceiver 35 to the subscriber device 20-k1-1, an optical modulator is inserted into the optical fiber transmission line 42-1. The optical transceiver 35 transmits the control signal to the optical modulator. The optical modulator modulates the light carrying the main signal M, which is transmitted from the optical transceiver 21-2 of the subscriber device 20-k2-2 to the optical transceiver 21-1 of the subscriber device 20-k1-1, with the low-frequency control signal. This allows the control signal to be superimposed as AMCC.

[0038] The control signal transmitted from the subscriber device 20 may be, for example, an optical path switching request or a notification upon abnormality detection, but is not limited to these and may be any signal. Conventional AMCC-compatible optical transceivers are intended for use in WDM (Wavelength Division Multiplex)-PON (Passive Optical Network). In this case, the control unit 31 and the subscriber device 20 have a master-slave relationship. A slave optical transceiver cannot transmit a control signal if it cannot receive a control signal from a master optical transceiver. The optical transceiver 21 of this embodiment can transmit a control signal to the optical transceiver 35 even if it cannot receive a control signal from the master optical transceiver 35. Thus, in this embodiment, by eliminating the master-slave relationship, the optical transceiver 21 of the subscriber device 20 can transmit a control signal regardless of whether it receives a signal from an optical transceiver of another device. Furthermore, the optical transceiver 35 of the control signal receiver 34 can receive a control signal regardless of the link-up state.

[0039] In the above-described embodiment, the optical branching unit 50 is provided on the optical fiber transmission line 42, but the optical branching unit 50 may be provided on the optical fiber transmission line 41. In this way, the optical branching unit 50 only needs to be provided on the optical fiber transmission line in which at least a part of the optical path P between the subscriber devices 20 is set.

[0040] According to the above-described embodiment, in the optical communication system, after an optical path between subscriber devices is opened, an optical branching unit provided in the optical transmission line branches the power of an optical signal transmitted from the subscriber device and outputs the branched power to a control unit. The optical transceiver in the control unit turns off light emission and receives the branched optical signal. Alternatively, if the optical transceiver in the control unit has a two-core configuration, the optical branching unit inputs and receives the branched optical signal from the input port, while opening the output port that outputs the optical signal. This configuration prevents interference caused by the optical branching unit merging light from the optical transceiver in the control unit with the main signal transmitted and received between the subscriber devices. Therefore, after the optical path is opened, it becomes possible to transmit a control signal from the subscriber device to the control unit while normally transmitting and receiving the main signal between the subscriber devices.

[0041] According to the embodiment described above, the optical communication system includes an optical switch, an optical branching unit, and an optical transmission / reception device. For example, the optical transmission / reception device is an optical transceiver 35. The optical switch inputs an optical signal transmitted by a first optical communication device from a first port. The optical switch outputs the input optical signal from a second port connected to a first optical transmission line included in an optical route on which an optical path for transmitting an optical signal between the first optical communication device and a second optical communication device is set. For example, the first optical communication device and the second optical communication device are subscriber devices 20-k1-1 and 20-k2-2. The optical branching unit branches a portion of the optical signal from the first optical transmission line that transmits the optical signal output from the second port, and outputs the branched optical signal to the second optical transmission line. For example, the first optical transmission line is an optical fiber transmission line 42, and the second optical transmission line is an optical fiber transmission line 43. The optical transmission / reception device is connected to the optical branching unit by the second optical transmission line, and inputs the optical signal branched by the optical branching unit. The optical transmission / reception device includes a receiving unit, a transmitting unit, and a blocking unit. The receiving unit obtains a signal having a destination different from that of the second optical communication device from the optical signal input from the second optical transmission path. The transmitting unit generates an optical signal using light emitted by the light source. The blocking unit prevents light from the light source included in the transmitting unit from being input to the second optical transmission path.

[0042] The cutoff unit is, for example, the power supply control unit 76. The cutoff unit stops the light emission of the light source. In addition, when the optical transceiver has an input port that inputs light from the second optical transmission path and outputs it to the receiving unit, and an output port that outputs the light output by the transmitting unit to the second optical transmission path, the cutoff unit may be an open output port.

[0043] The first optical communication device may include an optical transceiver having a receiving unit that receives an optical signal transmitted from a destination device, which is the optical communication device with which the communication is being made, via an optical transmission path, and a transmitting unit that generates an optical signal carrying a first signal addressed to the destination device and a second signal addressed to a destination different from the destination device, and outputs the optical signal to the optical transmission path.

[0044] According to this embodiment, it is possible to transmit a signal to a device other than the communication partner device while reducing the influence on the signal transmitted and received using the optical path between the communication partner device.

[0045] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configurations are not limited to these embodiments, and include designs within the scope of the gist of the present invention. [Explanation of symbols]

[0046] 1...Optical communication system 10-1, 10-2...optical switches 11...First port 12...Second port 20-1-1, 20-2-1, 20-3-1, 20-1-2, 20-2-2, 20-3-2...Subscriber equipment 21-1, 21-2...Optical transceiver 30...Control system 31-1, 31-2...Control section 32...Subscriber device management control unit 33...Optical SW control section 34...Control signal receiving unit 35...Optical transceiver 41-1, 41-2, 42-1, 42-2, 43-1, 43-2...Optical fiber transmission line 50-1, 50-2...Optical branching section 60...Optical communication network 70...Optical transceiver 71...Port 72…Separation part 73...Receiver 74...Transmitter 75...Light source 76...Power supply control unit 80...Optical transceiver 81...input port 82...Output port

Claims

1. an optical switch that receives, from a first port, an optical signal transmitted from a first optical communication device, the optical signal having a main signal destined for a second optical communication device and a control signal destined for a different destination from the second optical communication device superimposed thereon, and outputs the optical signal from a second port connected to a first optical transmission line included in an optical route in which an optical path between the first optical communication device and the second optical communication device is set; an optical branching unit that branches a part of the optical signal transmitted through the first optical transmission line and outputs the branched optical signal to a second optical transmission line; an optical transmitting / receiving device that receives the optical signal branched by the optical branching unit from the second optical transmission line, The optical transceiver comprises: a receiving unit that acquires the control signal from the optical signal input from the second optical transmission line; a transmitter that generates an optical signal using light emitted by the light source; a blocking unit that prevents light from the light source from being input to the second optical transmission line, Optical communication system.

2. an optical switch that receives an optical signal transmitted by a first optical communication device from a first port and outputs the optical signal from a second port connected to a first optical transmission line included in an optical route in which an optical path between the first optical communication device and a second optical communication device is set; an optical branching unit that branches a part of the optical signal transmitted through the first optical transmission line and outputs the branched optical signal to a second optical transmission line; an optical transmitting / receiving device that receives the optical signal branched by the optical branching unit from the second optical transmission line, The optical transceiver comprises: a receiving unit that acquires a signal having a destination different from that of the second optical communication device from the optical signal input from the second optical transmission line; a transmitter that generates an optical signal using light emitted by the light source; a blocking unit that prevents light from the light source from being input to the second optical transmission line; an input port that receives light from the second optical transmission line and outputs the light to the receiving unit; an output port that outputs the light output by the transmitter to the second optical transmission line, The blocking unit is the output port that is opened. Optical communication system.

3. a receiving unit that receives, from a second optical transmission line, an optical signal obtained by an optical branching unit provided in a first optical transmission line included in an optical route in which an optical path between a first optical communication device and a second optical communication device is set, the optical signal being transmitted from the first optical communication device and obtained by the second optical communication device branching a portion of the optical signal on which a main signal addressed to the second optical communication device and a control signal addressed to a different destination from the second optical communication device are superimposed, and that acquires the control signal from the input optical signal; a transmitter that generates an optical signal using light emitted by the light source; a blocking unit that prevents light from the light source from being input to the second optical transmission line; An optical transceiver comprising:

4. The blocking unit stops the light emission of the light source.

4. The optical transmitter / receiver according to claim 3.

5. The optical transceiver comprises: an input port that receives light from the second optical transmission line and outputs the light to the receiving unit; an output port that outputs the light output by the transmitter to the second optical transmission line, The blocking unit is the output port that is opened.

4. The optical transmitter / receiver according to claim 3.

6. a receiving unit that receives an optical signal from a second optical transmission line, the optical signal being obtained by branching a portion of an optical signal transmitted from the first optical communication device using an optical branching unit provided in a first optical transmission line included in an optical route in which an optical path is set between a first optical communication device and a second optical communication device, and that obtains a signal having a destination different from that of the second optical communication device from the received optical signal; a transmitter that generates an optical signal using light emitted by the light source; a blocking unit that prevents light from the light source from being input to the second optical transmission line; an input port that receives light from the second optical transmission line and outputs the light to the receiving unit; an output port that outputs the light output by the transmitter to the second optical transmission line; Equipped with The blocking unit is the output port that is opened. Optical transmitter and receiver.

7. a switching step in which an optical switch inputs, from a first port, an optical signal transmitted from a first optical communication device, on which a main signal destined for a second optical communication device and a control signal destined for a different destination from the second optical communication device are superimposed, and outputs the optical signal from a second port connected to a first optical transmission line included in an optical route in which an optical path between the first optical communication device and the second optical communication device is set; a branching step in which an optical branching unit branches a part of the optical signal transmitted through the first optical transmission line and outputs the branched optical signal to a second optical transmission line; a receiving step in which a receiving unit of an optical transmitting / receiving device receives the optical signal branched by the optical branching unit from the second optical transmission line and acquires the control signal from the received optical signal; a blocking step in which a blocking unit of the optical transceiver prevents light from a light source used by a transmitting unit of the optical transceiver to transmit an optical signal from being input to the second optical transmission path; An optical communication method comprising:

8. a receiving step in which a receiving unit inputs, from a second optical transmission line, a branched optical signal obtained by an optical branching unit provided in a first optical transmission line included in an optical route in which an optical path between a first optical communication device and a second optical communication device is set, the branched optical signal being an optical signal transmitted from the first optical communication device and having a main signal addressed to the second optical communication device and a control signal addressed to a different destination from the second optical communication device superimposed thereon, and acquires the control signal from the input optical signal; a blocking step in which a blocking unit prevents light from a light source used by a transmitting unit to transmit an optical signal from being input to the second optical transmission line; An optical communication method comprising:

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