Optical transceiver, optical communication system, optical transmission device, and optical transceiver setting method and program

Abstract

According to the present invention, this optical transceiver can autonomously set the channels of transmitted and received light signals. A wavelength-variable light transmission unit (10) is configured to be able to transmit a first channel setting light signal including first channel information indicating a channel of the first channel setting light signal. A wavelength-variable light reception unit (20) transmits second channel information included in a second channel setting light signal and indicating a channel of a second channel setting light signal, when the second channel setting light signal is received from another optical transceiver. A control unit (30) controls the wavelength-variable light transmission unit (10) and the wavelength-variable light reception unit (20). The control unit (30) sets, as a channel of a light signal received by the wavelength-variable light reception unit (20), a first channel indicated by the second channel information on the basis of the second channel information transmitted by the wavelength-variable light reception unit (20).

Description

[Technical field]

[0001] The present invention relates to an optical transceiver, an optical communication system, an optical transmission device, an optical transceiver setting method, and a computer-readable medium. [Background technology]

[0002] Optical communication systems that enable optical communication by connecting land base stations via optical cables are widely used. Each base station is equipped with optical transmission equipment equipped with one or more optical transceivers. When starting to use an optical transceiver, an initial setting is performed for the optical transceiver.

[0003] A technology has been disclosed in which optical transceivers adjust the transmission speed, data format, and transmission format before starting data communication between them (Patent Document 1). In this technology, a test signal in which the transmission speed and transmission format between the optical transceivers are set is transmitted and received between the optical transceivers. The transmission speed is set by comparing the transmission speed used to transmit the test signal with the transmission speed of the received test signal. The transmission format is set corresponding to the transmission path state estimated in response to error detection in the test signal. The data format is determined by transmitting and receiving information related to the data format after the transmission speed and transmission format have been determined. After these are determined, communication between the optical transceivers is started.

[0004] Also, a method has been proposed for starting two-way communication of data packets between optical transceivers that are not yet in communication (Patent Document 2). In this method, prior to two-way communication of data packets, a connection packet that has specific information about each optical transceiver and is transmitted between the optical transceivers at a speed lower than the transmission speed of the data packets via an optical fiber transmission line. Then, according to the specific information of the connection packet received by each optical transceiver, one of the optical transceivers is set as a master and the other as a slave, and the transmission method set by the master optical transceiver is notified to the slave optical transceiver by a setting packet. Two-way communication between the optical transceivers is performed using the transmission method set by this notification.

[0005] Furthermore, a method has been proposed for negotiating the wavelength used for communication between optical modules in a PON (Passive Optical Network) system consisting of an OLT (Optical Line Terminal) and an ONU (Optical Network Unit) (Patent Document 3). In this method, an optical module (referred to as a first optical module) periodically transmits a wavelength idle signal of a selected first wavelength to a counterpart optical module (referred to as a second optical module). This wavelength idle signal indicates that the selected first wavelength is available for use, and the second optical module, upon receiving the wavelength idle signal, transmits a wavelength request message of a second wavelength corresponding to the first wavelength to the first optical module. Upon receiving the wavelength request message, the first optical module transmits a wavelength permission message to the second optical module to permit the use of the selected wavelength. This determines the wavelength to be used for transmitting and receiving optical signals between the two optical modules. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2005-229298 A [Patent Document 2] JP 2005-229299 A [Patent Document 3] Special Publication No. 2017-539142 Summary of the Invention [Problem to be solved by the invention]

[0007] In general, optical transmission equipment is equipped with multiple optical transceivers, and it is necessary to perform initial settings to set the channel (wavelength) that each optical transceiver uses for transmission and reception. In this case, if the channel settings of the multiple optical transceivers installed in the optical transmission equipment are performed manually, the setting work takes a lot of time. Therefore, from the viewpoint of reducing the work time, it is desirable to be able to autonomously set the channel of the optical signal that the optical transceiver transmits and receives as the initial setting when the optical transceiver is installed in the optical transmission equipment.

[0008] In the method of Patent Document 3, the channel (wavelength) to be used for transmission and reception can be set by performing wavelength negotiation between two optical modules (optical transceivers), but this is premised on the fact that optical signals of a specific channel can be transmitted and received between the two optical modules in the first place. In other words, the first and second wavelengths to be used must be assigned manually. In other words, the method of Patent Document 3 merely uses the assigned channel to confirm that the transmission and reception path is available, and cannot autonomously set the channel to be used.

[0009] The present invention has been made in view of the above circumstances, and has an object to autonomously set a channel for an optical signal transmitted and received by an optical transceiver. [Means for solving the problem]

[0010] An optical transceiver according to one embodiment of the present invention comprises a tunable optical transmitter configured to be capable of transmitting a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal, a tunable optical receiver that, when receiving a second channel setting optical signal from another optical transceiver, transfers second channel information indicating a channel of the second channel setting optical signal that is included in the second channel setting optical signal, and a control unit that controls the tunable optical transmitter and the tunable optical receiver, and the control unit sets the first channel indicated by the second channel information as the channel of the optical signal received by the tunable optical receiver, based on the second channel information transferred by the tunable optical receiver.

[0011] An optical communication system according to one embodiment of the present invention includes a first optical transmission device having a plurality of optical transceivers including a first optical transceiver and a first optical multiplexer / demultiplexer that multiplexes and outputs optical signals output by the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels; a second optical transmission device having a plurality of optical transceivers including a second optical transceiver and a second optical multiplexer / demultiplexer that multiplexes and outputs optical signals output by the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels; and an optical cable connecting the first optical transmission device and the second optical transmission device, wherein the first optical transceiver is a first the wavelength-tunable optical transmitting unit configured to be capable of transmitting a first channel setting optical signal including first channel information indicating a channel of the channel setting optical signal; a wavelength-tunable optical receiving unit configured to transfer second channel information indicating a channel of the second channel setting optical signal, which is included in the second channel setting optical signal when the second channel setting optical signal is received from the second optical transceiver; and a control unit configured to control the wavelength-tunable optical transmitting unit and the wavelength-tunable optical receiving unit, wherein the control unit sets the first channel indicated by the second channel information as the channel of the optical signal received by the wavelength-tunable optical receiving unit, based on the second channel information transferred by the wavelength-tunable optical receiving unit.

[0012] An optical transmission device according to one embodiment of the present invention comprises a plurality of optical transceivers, and an optical multiplexer / demultiplexer that multiplexes and outputs optical signals output by the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels, each of the plurality of optical transceivers comprising a tunable optical transmitter configured to transmit a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal, a tunable optical receiver that transfers second channel information indicating a channel of the second channel setting optical signal that is included in the second channel setting optical signal when the second channel setting optical signal is received from another optical transceiver provided in another optical transmission device, and a control unit that controls the tunable optical transmitter and the tunable optical receiver, and the control unit sets the first channel indicated by the second channel information as the channel of the optical signal received by the tunable optical receiver based on the second channel information transferred by the tunable optical receiver.

[0013] A method for configuring an optical transceiver that is one aspect of the present invention includes transmitting a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal, and upon receiving a second channel setting optical signal from another optical transceiver, forwarding second channel information contained in the second channel setting optical signal indicating the channel of the second channel setting optical signal, and setting the first channel indicated by the second channel information as the channel of the optical signal to be received based on the forwarded second channel information.

[0014] A non-transitory computer-readable medium having a program stored thereon that is one aspect of the present invention causes an optical transceiver having a control unit configured as an arithmetic unit capable of controlling a tunable optical transmitting unit and a tunable optical receiving unit to execute the following operations: transmitting a first channel setting optical signal from the tunable optical transmitting unit, the first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal; when receiving a second channel setting optical signal from another optical transceiver, transferring second channel information included in the second channel setting optical signal and indicating the channel of the second channel setting optical signal by the tunable optical receiving unit; and setting the first channel indicated by the second channel information as the channel of the optical signal received by the tunable optical receiving unit based on the second channel information transferred by the tunable optical receiving unit. Effect of the Invention

[0015] According to the present invention, an optical transceiver can autonomously set a channel for transmitting and receiving optical signals. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram illustrating a basic configuration of an optical communication system according to a first embodiment. [Diagram 2] 1 is a diagram illustrating a schematic configuration of an optical transmission device according to a first embodiment and an example of transmission and reception of an optical signal; [Diagram 3] FIG. 2 is a diagram illustrating a configuration of a channel setting optical signal. [Figure 4] FIG. 1 is a diagram illustrating a basic configuration of an optical transceiver according to a first embodiment. [Diagram 5] FIG. 2 is a diagram illustrating a more detailed configuration of the optical transceiver according to the first embodiment. [Figure 6] 1 is a diagram illustrating transmission of a channel setting optical signal in the optical transceiver according to the first embodiment. FIG. [Figure 7] FIG. 2 illustrates reception of a channel setting optical signal in the optical transceiver according to the first embodiment. [Figure 8] 1A and 1B are diagrams illustrating an example of a channel setting optical signal transmitted and received between two optical transceivers in a channel setting process. [Figure 9] FIG. 11 is a diagram showing state transitions in a channel setting process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same elements are given the same reference numerals, and duplicated explanations will be omitted as necessary.

[0018] First embodiment An optical communication system 1000 according to a first embodiment will be described. FIG. 1 shows a schematic diagram of a basic configuration of the optical communication system 1000 according to the first embodiment. In the optical communication system 1000, optical transmission devices 1 and 2 are provided in land terminal stations BS1 and BS2, respectively. The optical transmission devices 1 and 2 are connected by optical cables C1 and C2. The optical cables C1 and C2 may be laid on land or on the seabed. In this example, the optical cable C1 is used as a cable for transmitting an optical signal transmitted from the optical transmission device 1 to the optical transmission device 2. The optical cable C2 is used as a cable for transmitting an optical signal transmitted from the optical transmission device 2 to the optical transmission device 1. Note that one or more optical amplifiers AMP may be inserted into the optical cables C1 and C2 to compensate for optical signals attenuated by transmission.

[0019] 1 shows a simplified configuration of the optical communication system for the sake of simplicity, and for example, one optical transmission device may be communicably connected to two or more optical transmission devices via an optical cable. Also, an optical add / drop device that adds / drops optical signals may be inserted into the optical cable as necessary to branch a branch path from the trunk path. However, this is merely an example, and it goes without saying that the optical communication system may be configured to have any path (trunk path and branch path) that enables optical communication between any number of optical transmission devices.

[0020] The configuration of the optical transmission device will be explained. The optical transmission device has multiple optical transceivers, an optical multiplexer that multiplexes optical signals to be transmitted and outputs a multiplexed optical signal, and an optical demultiplexer that demultiplexes the received multiplexed optical signal to each optical transceiver. In the following, for simplicity, the optical multiplexer and optical demultiplexer are integrated and treated as one optical multiplexer / demultiplexer.

[0021] 2 shows a schematic diagram of an example of the configuration of optical transmission devices 1 and 2 according to the first embodiment and transmission and reception of optical signals. The optical transmission device 1 includes a plurality of optical transceivers and an optical multiplexer / demultiplexer M1 (also referred to as a second optical multiplexer / demultiplexer). In this example, the optical transmission device 1 includes 25 optical transceivers A1 to A25. Two different channels are assigned to each of the optical transceivers A1 to A25.

[0022] The number of ports of the optical multiplexer / demultiplexer M1 connected to the optical transceivers is equal to the number of channels, and the transmission port of the optical transceiver Ai (i is an integer between 1 and 25) is connected to the port of the channel CH(2i-1) of the optical multiplexer / demultiplexer M1, and the reception port is connected to the port of the channel CH(2i). In other words, the optical transceiver Ai is assigned the transmission channel CH(2i-1) and the reception channel CH(2i). That is, the optical transceivers A1, A2, A3, . . . , A25 are assigned the channels CH1 and CH2, CH3 and CH4, CH5 and CH6, . . . , CH49 and CH50. In this way, a specific channel is assigned to each of the two ports of the optical transceiver without overlapping within the optical transmission device.

[0023] The optical transmission device 2 has a similar configuration to the optical transmission device 1. That is, the optical transmission device 2 has 25 optical transceivers B1 to B25 and an optical multiplexer / demultiplexer M2 (also referred to as a first optical multiplexer / demultiplexer).

[0024] The number of ports of the optical multiplexer / demultiplexer M2 connected to the optical transceivers is equal to the number of channels, and the receiving port of the optical transceiver Bi is connected to the port of channel CH(2i-1) of the optical multiplexer / demultiplexer M2, and the transmitting port is connected to the port of channel CH(2i). In other words, the optical transceiver Bi is assigned a transmitting channel CH(2i) and a receiving channel CH(2i-1). That is, the optical transceivers B1, B2, B3, . . . , B25 are assigned channels CH1 and CH2, CH3 and CH4, CH5 and CH6, . . . , CH49 and CH50. In this way, a specific channel is assigned to each of the two ports of the optical transceiver without overlapping within the optical transmission device.

[0025] With the above configuration, two common channels are assigned to the optical transceiver Ai and the optical transceiver Bi, and optical signals can be transmitted and received using these two channels.

[0026] In this example, the transmission and reception paths of optical signals are shown, focusing on optical transceiver A2 in optical transmission device 1 and optical transceiver B2 in optical transmission device 2. Optical transceiver A2 transmits an optical signal using channel CH3, and the transmitted optical signal on channel CH3 is received by optical transceiver B2. Optical transceiver B2 transmits an optical signal using channel CH4, and the transmitted optical signal on channel CH4 is received by optical transceiver A2.

[0027] In FIG. 2, attention is focused on only the optical transceiver A2 and the optical transceiver B2 for the sake of simplicity of explanation, and it goes without saying that the other optical transceivers can also transmit and receive optical signals using two channels in a similar manner.

[0028] In this way, in order to transmit and receive optical signals of a specific channel, the channel to be used is set in the transmitting optical transceiver and the receiving optical transceiver. Generally, the task of setting the channel in the optical transceiver is performed as part of the initial setting task when the optical transceiver is installed in the optical transmission device.

[0029] However, when using a maximum of 50 channels as in the above-mentioned optical communication system, it is necessary to perform the setting work for two channels for each of the total 50 optical transceivers in the two optical transmission devices, that is, 100 times. However, if this setting work is performed manually, there is a problem that the required work time is enormous. In addition, since it is necessary to perform a large number of setting tasks without making any mistakes, there may be a problem in terms of reliability when performing the setting work manually.

[0030] In this embodiment, in order to address such problems, an optical transceiver that autonomously performs channel setting processing when the optical transceiver is attached to an optical transmission device will be described.

[0031] For example, when the optical transceiver A2 and the optical transceiver B2 are installed in an optical transmission device, the optical transceiver A2 and the optical transceiver B2 autonomously execute channel setting processing. At this time, a channel setting optical signal is transmitted and received between the optical transceiver A2 and the optical transceiver B2.

[0032] Fig. 3 shows a schematic configuration of a channel setting optical signal. The channel setting optical signal S includes at least local channel information L and remote channel information R held in the optical transceiver. The local channel information L is information indicating the channel of the channel setting optical signal S transmitted by the optical transceiver when the optical transceiver transmits the channel setting optical signal S in the channel setting process. The remote channel information R is information indicating the channel of the channel setting optical signal S received by the optical transceiver when the optical transceiver receives the channel setting optical signal S in the channel setting process. The channel setting optical signal S may include other information as necessary. Fig. 3 shows an example in which the channel setting optical signal S includes header information OH.

[0033] Here, the configuration of the optical transceiver according to the present embodiment will be described. Fig. 4 shows a schematic diagram of the basic configuration of the optical transceiver according to the first embodiment. Fig. 5 shows the configuration of the optical transceiver according to the first embodiment in more detail. Note that since the optical transceivers A1 to A25 and B1 to B25 have the same configuration, the optical transceiver 100 having the same structure as these will be described as a representative.

[0034] The optical transceiver 100 includes a tunable optical transmitter 10, a tunable optical receiver 20, and a controller 30. The controller 30 controls the operations of the tunable optical transmitter 10 and the tunable optical receiver 20 in response to, for example, a command signal INS provided from an optical transmission device in which the optical transceiver 100 is implemented.

[0035] The wavelength-tunable optical transmitter 10 is configured to be able to change the wavelength of the optical signal to be transmitted, i.e., the channel. The wavelength-tunable optical transmitter 10 has a driver 11 and an optical signal transmitter 12. The driver 11 outputs a drive signal DRV to the optical signal transmitter 12 based on a received main signal (data signal) IN. The wavelength-tunable optical signal transmitter 12 is configured as, for example, a TOSA (Transmitter Optical Sub-Assembly), and is configured to be able to output an optical signal LS1 modulated in response to the drive signal DRV.

[0036] The tunable optical receiving unit 20 is configured to be able to change the wavelength of the received optical signal, i.e., the channel. The tunable optical receiving unit 20 has an amplifier 21 and an optical signal receiving unit 22. The tunable optical signal receiving unit 22 is configured, for example, as a ROSA (Receiver Optical Sub-Assembly), and converts the received optical signal LS2 into an output signal DAT, which is an electrical signal, and outputs it to the amplifier 21. The amplifier 21 is configured, for example, as a limiting amplifier, and amplifies the output signal DAT to a predetermined amplitude, and outputs the amplified output signal OUT to the outside of the optical transceiver 100, for example, to an optical transmission device in which the optical transceiver 100 is implemented.

[0037] Next, the transmission of the channel setting optical signal in the optical transceiver 100 will be described. FIG. 6 shows the transmission of the channel setting optical signal SA in the optical transceiver 100. The control unit 30 superimposes a low-speed (low-frequency) signal on the drive signal DRV output by the drive unit 11 by providing a control signal CON to the drive unit 11. For example, the drive signal DRV can be on / off modulated, that is, the amplitude can be set to 0 or 1, by connecting the serial port of the control unit 30 to the output amplitude Disable terminal of the drive unit 11 and outputting the control signal CON to the output amplitude Disable terminal. The optical signal transmission unit 12 can output the channel setting optical signal SA that has been on / off modulated in response to the drive signal DRV that has been low-speed modulated in order to transmit the channel setting optical signal SA. At this time, by carrying the local channel information L and the remote channel information R on the control signal CON, the channel setting optical signal SA output by the optical signal transmission unit 12 includes the local channel information L and the remote channel information R.

[0038] Next, the reception of the channel setting optical signal in the optical transceiver 100 will be described. FIG. 7 shows the reception of the channel setting optical signal SB in the optical transceiver 100. When the optical signal receiving unit 22 receives the channel setting optical signal SB generated as described above, the amplitude of the output signal DAT rises and falls according to the amplitude of the on / off modulated channel setting optical signal SB. The amplifying unit 21 detects the amplitude of the output signal DAT and outputs a detection signal DET indicating the detection result to the control unit 30. This allows the control unit 30 to receive the local channel information L and the remote channel information R regardless of the channel of the channel setting optical signal SB, simply by monitoring the amplitude of the channel setting optical signal SB.

[0039] Next, the channel setting process of the optical transceiver using the above-mentioned channel setting optical signal will be described. The optical transceiver A2 and the optical transceiver B2 determine the channel to be used for transmitting and receiving optical signals between each other by changing the local channel information L, i.e., by transmitting the channel setting optical signal while sweeping the local channel, in the procedure shown below. Figure 8 shows an example of the channel setting optical signal transmitted and received between the optical transceiver A2 and the optical transceiver B2 in the channel setting process. Figure 9 shows the state transition in the channel setting process.

[0040] At the start of the channel setting process, the optical transceivers A2 and B2 are in an unknown state of the transmission channel and reception channel to be set (hereinafter, state EU: Each channel Unknown). In other words, both the optical transceiver of the transmission partner and the optical transceiver that transmits the optical signal to be received have not been specified.

[0041] Thereafter, the optical transceivers A2 and B2 repeatedly transmit the channel setting optical signal while sweeping the local channels. Here, the local channels are assumed to be swept in ascending order starting from channel CH1.

[0042] In the following, the optical transceiver B2 is also referred to as the first optical transceiver, and the optical transceiver A2 is also referred to as the second optical transceiver. The channel setting optical signal output by the optical transceiver B2 is also referred to as the first channel setting optical signal. The channel setting optical signal output by the optical transceiver A2 is also referred to as the second channel setting optical signal.

[0043] Channel CH3 is also referred to as the first channel, and channel CH4 is also referred to as the second channel.

[0044] The local channel information LB of the optical transceiver B2 is also referred to as the first channel information, and the local channel information LA of the optical transceiver A2 is also referred to as the second channel information. The remote channel information RB of the optical transceiver B2 is also referred to as the third channel information, and the local channel information LA of the optical transceiver A2 is also referred to as the second channel information.

[0045] (1) SA1 / LA:CH1,RA:NONE In the example of Fig. 8, the optical transceiver A2 first transmits a channel setting optical signal SA1 of channel CH1, whose local channel information LA is channel CH1 and whose remote channel information RA is empty (NONE). In this example, channel CH1 is the channel used for transmission from the optical transceiver A1 to the optical transceiver B1. That is, the port of channel CH1 of the optical multiplexer / demultiplexer M2 of the optical transmission device 2 is connected to the receiving port of the optical transceiver B1. Therefore, the channel setting optical signal SA1 is blocked by the optical multiplexer / demultiplexer M2 and does not reach the optical transceiver B2.

[0046] (2) SB1 / LB:CH1,RB:NONE Next, optical transceiver B2 transmits a channel setting optical signal SB1 for channel CH1, whose local channel information LB is channel CH1 and whose remote channel information RB is empty (NONE). Since the transmission port of optical transceiver A1 is connected to the port for channel CH1 of optical multiplexer / demultiplexer M1 of optical transmission device 1, the channel setting optical signal SB1 is blocked by optical multiplexer / demultiplexer M1 and does not reach optical transceiver A2.

[0047] (3) SA2 / LA:CH2,RA:NONE Next, the optical transceiver A2 transmits a channel setting optical signal SA2 of channel CH2, whose local channel information LA is channel CH2 and whose remote channel information RA is empty (NONE). In this example, channel CH2 is the channel used for transmission from the optical transceiver B1 to the optical transceiver A1. That is, the port of channel CH2 of the optical multiplexer / demultiplexer M2 of the optical transmission device 2 is connected to the transmission port of the optical transceiver B1. Therefore, the channel setting optical signal SA2 is blocked by the optical multiplexer / demultiplexer M2 and does not reach the optical transceiver B2.

[0048] (4) SB2 / LA:CH2,RA:NONE Next, the optical transceiver B2 transmits a channel setting optical signal SB2 for channel CH2, whose local channel information LB is channel CH2 and whose remote channel information RB is empty (NONE). Because the receiving port of the optical transceiver A1 is connected to the port for channel CH2 of the optical multiplexer / demultiplexer M1 of the optical transmission device 1, the channel setting optical signal SB2 is blocked by the optical multiplexer / demultiplexer M1 and does not reach the optical transceiver A2.

[0049] (5)SA3 / LA:CH3,RA:NONE, state transition: EU→PK Next, the optical transceiver A2 transmits a channel setting optical signal SA3 for channel CH3, whose local channel information L is channel CH3 and whose remote channel information R is empty (NONE). In this example, channel CH3 is the channel used for transmission from the optical transceiver A2 to the optical transceiver B2. That is, the port for channel CH3 of the optical multiplexer / demultiplexer M2 of the optical transmission device 2 is connected to the receiving port of the optical transceiver B2. Therefore, the channel setting optical signal SA3 for channel CH3 is received by the optical transceiver B2 via the optical multiplexer / demultiplexer M2.

[0050] This allows the optical transceiver B2 to receive channel CH3 as the local channel information LA of the optical transceiver A2. Since the local channel information LA of the optical transceiver A2 is remote channel information RB for the optical transceiver B2, the optical transceiver B2 fixes the remote channel information RB to channel CH3.

[0051] At this time, the optical transceiver B2 enters a state in which it has detected the transmission channel of the partner optical transceiver A (state PK: Partner CH Known), and the state transitions from EU to PK.

[0052] (6)SB4 / LB:CH3,RB:NONE Next, optical transceiver B2 transmits a channel setting optical signal SB3 for channel CH3, whose local channel information LB is for channel CH3 and whose remote channel information RB is for channel CH3. Since the transmitting port of optical transceiver A2 is connected to the port for channel CH3 of optical multiplexer / demultiplexer M1 of optical transmission device 1, the channel setting optical signal SB3 for channel CH3 is blocked by optical multiplexer / demultiplexer M1 and does not reach optical transceiver A2.

[0053] (7) SA4 / LA:CH4,RA:NONE Next, the optical transceiver A2 transmits a channel setting optical signal SA4 for channel CH4, whose local channel information LA is channel CH4 and whose remote channel information RA is empty (NONE). In this example, channel CH4 is the channel used for transmission from the optical transceiver B2 to the optical transceiver A2. That is, the port for channel CH4 of the optical multiplexer / demultiplexer M2 of the optical transmission device 2 is connected to the transmission port of the optical transceiver B2. Therefore, the channel setting optical signal SA4 for channel CH4 is blocked by the optical multiplexer / demultiplexer M2 and does not reach the optical transceiver B2.

[0054] (8) SB4 / LB: CH4, RA: CH3, state transition: EU → EK Next, the optical transceiver B2 transmits a channel setting optical signal SB4 for channel CH4, whose local channel information LB is for channel CH4 and whose remote channel information RB is for channel CH3. The receiving port of the optical transceiver B2 is connected to the port for channel CH4 of the optical multiplexer / demultiplexer M1 of the optical transmission device 1. Therefore, the channel setting optical signal SB4 for channel CH4 is received by the optical transceiver A2 via the optical multiplexer / demultiplexer M1.

[0055] This allows the optical transceiver A2 to receive channel CH4 as the local channel information LB of the optical transceiver B2. Since the local channel information LB of the optical transceiver B2 is the remote channel information RA for the optical transceiver A2, the optical transceiver A2 fixes the remote channel information RA to channel CH4.

[0056] In addition, the optical transceiver A2 can receive channel CH3 as the remote channel information RB of the optical transceiver B2. Since the remote channel information RB of the optical transceiver B2 is local channel information LA for the optical transceiver A2, the optical transceiver A2 fixes the local channel information LA to channel CH3. Since fixing the local channel information LA to channel CH3 sets the transmission channel of the optical transceiver A2, the optical transceiver A2 stops channel sweeping.

[0057] At this time, the optical transceiver A2 enters a state in which it has detected the transmission channel of the partner optical transceiver B2 and the channel available for transmission from the optical transceiver A2 to the optical transceiver B2 (state EK: Each CH Known), and the state transitions from EU to EK.

[0058] (9) SA0 / LA:CH3, RA:CH4, state transition:PK→EK Next, the optical transceiver A2 transmits a channel setting optical signal SA0 for channel CH3, in which the local channel information LA is fixed to channel CH3 and the remote channel information RA is fixed to channel CH4. The channel setting optical signal SA0 for channel CH3 is received by the optical transceiver B2.

[0059] In this case, the optical transceiver B2 can receive channel CH4 as the remote channel information RA of the optical transceiver A2. Since the remote channel information RA of the optical transceiver A2 is local channel information LB for the optical transceiver B2, the optical transceiver B2 fixes the local channel information LB to channel CH4. Since fixing the local channel information LB to channel CH4 sets the transmission channel of the optical transceiver B2, the optical transceiver B2 stops channel sweeping.

[0060] At this time, the optical transceiver B2 enters a state (state EK) in which it has detected the transmission channel of the partner optical transceiver A2 and a channel available for transmission from the optical transceiver B2 to the optical transceiver A2, and the state transitions from PK to EK.

[0061] (10) SB0 / LB: CH4, RB: CH3, state transition: EK → LE Next, the optical transceiver B2 transmits a channel setting optical signal SB0 for channel CH4, in which the local channel information LB is fixed to channel CH4 and the remote channel information RB is fixed to channel CH3. The channel setting optical signal SB0 for channel CH4 is received by the optical transceiver A2.

[0062] In this case, the optical transceivers A2 and B2 can confirm that the local channel information LA of the optical transceiver A2 and the remote channel information RB of the optical transceiver B2 match on channel CH3, and that the local channel information LB of the optical transceiver B2 and the remote channel information RA of the optical transceiver A2 match on channel CH4. Therefore, in this case, the optical transceivers A2 and B2 can confirm that the channel to be used for transmission and the channel to be used for reception have been determined. Therefore, since no further channel setting processing is required, the optical transceivers A2 and B2 end the channel setting processing assuming that the connection has been established (state LE: Link Established).

[0063] As a result, after the channel setting process is completed, the optical transceiver A2 and the optical transceiver B2 can transmit and receive optical signals using the channels CH3 and CH4.

[0064] As described above, according to this configuration, the optical transceiver can autonomously set the channel of the optical signal to be transmitted and the channel of the optical signal to be received by referring to the information contained in the channel setting signal that it receives.

[0065] This makes it possible to reduce the time required for channel setting in the optical transceiver, even when many channels are used, such as in the optical communication system described above.

[0066] In manual channel setting work, it may take minutes to set one channel, for example about 10 minutes. In contrast, with this configuration, although this varies depending on the configuration of the optical communication system, automatic setting of one channel is possible in seconds, for example about a few seconds. Thus, it can be seen that with this configuration, the time required for channel setting of an optical transceiver can be significantly reduced.

[0067] In addition, by having the optical transceiver autonomously perform channel setting, not only can the manual work by workers be reduced, but the workers can perform other tasks while the channel setting process is in progress, which is also advantageous in terms of labor savings.

[0068] Furthermore, since the optical transceiver can autonomously perform channel setting, it is possible to prevent mistakes such as setting the wrong channel that can occur when channel setting is done manually, thereby improving the reliability of channel setting.

[0069] In addition, there may be a case where an optical transmission device is started with fewer optical transceivers than the maximum number of transceivers, and then additional optical transceivers are added. In this case, manual channel setting requires cumbersome work such as investigating channels that are already in use and setting channels other than the channels that are in use. In contrast, the optical transceiver according to the present embodiment can autonomously set channels even if the channels that are already in use are not known, which is advantageous in terms of reducing the time and labor required for adding additional optical transceivers.

[0070] In the above description, the optical transceivers A2 and B2 have been focused on, but it goes without saying that the channel setting process can be similarly performed for the other optical transceivers A1, A3 to A25, B1, and B3 to B25.

[0071] In the above description, the optical transceiver changes the channel of the channel setting optical signal in ascending order starting from channel CH1, but this is merely an example. For example, the optical transceiver may change the channel of the channel setting optical signal in descending order. Also, for example, the optical transceiver may change the channel of the channel setting optical signal in any order other than descending order or ascending order.

[0072] Other embodiments The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present invention. For example, the optical transmission device may be connected to various networks including trunk routes and branch routes, in addition to the network shown in FIG.

[0073] The numbers of optical transceivers and channels provided in the optical transmission device are merely examples, and any number of optical transceivers and any number of channels may be provided.

[0074] In the above-described embodiment, it has been described that wavelength multiplexed signals are transmitted between optical transmission devices. However, it goes without saying that various multiplexing methods other than wavelength multiplexing can be applied to the transmitted optical signals, and various modulation methods can be applied.

[0075] The configuration of the optical transceiver described above is simplified in order to explain the optical transceiver according to the above embodiment, and it goes without saying that it may include various components, such as a CDR (Clock Data Recovery) unit.

[0076] In the above description, an example has been described in which an optical signal obtained by on / off modulation is used as the channel setting optical signal. However, an optical signal obtained by phase shift keying other than on / off modulation may also be used as the channel setting optical signal.

[0077] In the above embodiment, the present invention has been described as a hardware configuration, but the present invention is not limited to this. The present invention can also be realized by having a CPU (Central Processing Unit) execute a computer program to control the wavelength-tunable optical transmitter and the wavelength-tunable optical receiver by the control unit and the channel setting process shown in Figs. 8 and 9. The above-mentioned program can be stored using various types of non-transitory computer readable medium and supplied to the computer. The non-transitory computer readable medium includes various types of tangible storage medium. Examples of the non-transitory computer readable medium include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROM (Read Only Memory), CD-R, CD-R / W, and semiconductor memory (e.g., mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). The program may also be supplied to the computer by various types of transitory computer readable medium. Examples of the temporary computer-readable medium include an electric signal, an optical signal, and an electromagnetic wave. The temporary computer-readable medium can provide the program to the computer via a wired communication path such as an electric wire or an optical fiber, or a wireless communication path.

[0078] The present invention has been described above, but it can also be described as follows.

[0079] (Supplementary Note 1) An optical transceiver comprising: a tunable optical transmitter configured to be capable of transmitting a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal; a tunable optical receiver that, when receiving a second channel setting optical signal from another optical transceiver, transfers second channel information indicating a channel of the second channel setting optical signal, which is included in the second channel setting optical signal; and a control unit that controls the tunable optical transmitter and the tunable optical receiver, wherein the control unit sets the first channel indicated by the second channel information as the channel of an optical signal received by the tunable optical receiver, based on the second channel information transferred by the tunable optical receiver.

[0080] (Supplementary Note 2) The optical transceiver described in Supplementary Note 1, wherein the control unit controls the wavelength-tunable optical transmitting unit so that the first channel information and third channel information indicating the first channel are included in the first channel setting optical signal.

[0081] (Supplementary Note 3) The optical transceiver of Supplementary Note 2, wherein when the second channel setting optical signal includes the second channel information and fourth channel information indicating the second channel based on the third channel information indicating a second channel different from the first channel included in the first channel setting optical signal by the other optical transceiver, the wavelength-tunable optical receiving unit transfers the fourth channel information, and the control unit sets the second channel as the channel of the optical signal transmitted by the wavelength-tunable optical transmitting unit based on the fourth channel information transferred by the wavelength-tunable optical receiving unit.

[0082] (Supplementary Note 4) The optical transceiver according to Supplementary Note 3, wherein the control unit controls the wavelength-tunable optical transmitting unit to stop transmitting the first channel setting optical signal.

[0083] (Supplementary Note 5) The optical transceiver described in any one of Supplementary Notes 1 to 4, wherein, when the control unit is not receiving the second channel setting optical signal, the control unit changes the channel of the first channel setting optical signal to a channel that has not yet been set as the channel of the first channel setting optical signal, and outputs the first channel setting optical signal.

[0084] (Supplementary Note 6) The optical transceiver according to any one of Supplementary Notes 1 to 5, wherein the control unit is configured such that the first and second channel setting optical signals are on / off modulated optical signals.

[0085] (Supplementary Note 7) The optical transceiver described in Supplementary Note 6, wherein the wavelength-tunable optical transmitter unit has a driver unit that outputs a drive signal corresponding to an input signal, and a wavelength-tunable optical output unit that outputs an optical signal modulated according to the drive signal, and the control unit controls the driver unit so that the first channel setting optical signal modulated on / off according to the drive signal is output from the wavelength-tunable optical output unit.

[0086] (Supplementary Note 8) A first optical transmission device having a plurality of optical transceivers including a first optical transceiver and a first optical multiplexer / demultiplexer that multiplexes and outputs optical signals output by the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels; a second optical transmission device having a plurality of optical transceivers including a second optical transceiver and a second optical multiplexer / demultiplexer that multiplexes and outputs optical signals output by the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels; and an optical cable connecting the first optical transmission device and the second optical transmission device, wherein the first optical transceiver is a first channel setting optical signal. a tunable optical transmitting unit configured to be capable of transmitting a first channel setting optical signal including first channel information indicating a channel of a second channel setting optical signal, a tunable optical receiving unit configured to transfer second channel information indicating a channel of the second channel setting optical signal, the second channel information being included in the second channel setting optical signal when the second channel setting optical signal is received from the second optical transceiver, and a control unit for controlling the tunable optical transmitting unit and the tunable optical receiving unit, wherein the control unit sets the first channel indicated by the second channel information as a channel of an optical signal received by the tunable optical receiving unit, based on the second channel information transferred by the tunable optical receiving unit.

[0087] (Supplementary Note 9) An optical transmission device comprising: a plurality of optical transceivers; and an optical multiplexer / demultiplexer that multiplexes and outputs optical signals output by the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels, each of the plurality of optical transceivers comprising: a tunable optical transmitter configured to be able to transmit the first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal; a tunable optical receiver that transfers second channel information indicating a channel of the second channel setting optical signal, the second channel information being included in the second channel setting optical signal when the second channel setting optical signal is received from another optical transceiver provided in another optical transmission device; and a control unit that controls the tunable optical transmitter and the tunable optical receiver, wherein the control unit sets the first channel indicated by the second channel information as the channel of the optical signal received by the tunable optical receiver, based on the second channel information transferred by the tunable optical receiver.

[0088] (Supplementary Note 10) A method for configuring an optical transceiver, comprising: transmitting a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal; when receiving a second channel setting optical signal from another optical transceiver, forwarding second channel information indicating the channel of the second channel setting optical signal, which is included in the second channel setting optical signal; and setting the first channel indicated by the second channel information as the channel of a received optical signal based on the forwarded second channel information.

[0089] (Supplementary Note 11) In an optical transceiver having a control unit configured as an arithmetic unit capable of controlling a wavelength-tunable optical transmitting unit and a wavelength-tunable optical receiving unit, a non-transitory computer-readable medium having a program stored thereon causes the control unit to execute the following operations: transmitting from the wavelength-tunable optical transmitting unit a first channel setting optical signal including first channel information indicating a channel of a first channel setting optical signal; transferring by the wavelength-tunable optical receiving unit second channel information indicating a channel of the second channel setting optical signal, which is included in the second channel setting optical signal, when a second channel setting optical signal is received from another optical transceiver; and setting by the control unit, based on the second channel information transferred by the wavelength-tunable optical receiving unit, the first channel indicated by the second channel information as a channel of an optical signal received by the wavelength-tunable optical receiving unit.

[0090] Although the present invention has been described above with reference to the embodiment, the present invention is not limited to the above. Various modifications that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the invention. [Explanation of symbols]

[0091] 1, 2 Optical transmission equipment 10 Tunable optical transmitter 11 Drive unit 12 Optical signal transmitter 20 Tunable optical receiver 21 Amplification section 22 Optical signal receiving section 30 Control section 100, A1~A25, B1~B25 Optical transceiver 1000 Optical Communication Systems AMP Optical Amplifier BS1, BS2 terminal station C1, C2 Optical Cable CON Control Signal DAT Output Signal DET Detection signal DRV drive signal IN main signal INS command signal L, LA, LB Local channel information LS1, LS2 optical signal M1, M2 optical multiplexer / demultiplexer OH Header Information OUT Output signal R, RA, RB Remote channel information S, SA, SA0~SA4, SB, SB0~SB4 Optical signals for channel setting

Claims

1. A wavelength-tunable optical transmitter configured to be capable of autonomously transmitting a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal when attached to an optical transmission device; a wavelength-tunable optical receiving unit that, when receiving a second channel setting optical signal from another optical transceiver, transfers second channel information that is included in the second channel setting optical signal and indicates a channel of the second channel setting optical signal; a control unit for controlling the wavelength-tunable optical transmitter and the wavelength-tunable optical receiver, The control unit sets, based on the second channel information transferred by the wavelength-tunable optical receiving unit, a first channel indicated by the second channel information as a channel of an optical signal to be received by the wavelength-tunable optical receiving unit; the first channel setting optical signal is superimposed on the optical signal transmitted by the wavelength-tunable optical transmitter by modulating the optical signal transmitted by the wavelength-tunable optical transmitter by a phase modulation method other than an on / off modulation method that is different from a modulation method applied to a data signal; the second channel setting optical signal is superimposed on the optical signal received by the wavelength-tunable optical receiving unit by modulating the optical signal received by the wavelength-tunable optical receiving unit using a phase modulation method other than the on / off modulation method; Optical transceiver.

2. the control unit controls the wavelength-tunable optical transmission unit so that the first channel information and third channel information indicating the first channel are included in the first channel setting optical signal.

2. The optical transceiver of claim 1.

3. when the second channel setting optical signal includes the second channel information and fourth channel information indicating the second channel based on the first channel information indicating a second channel different from the first channel, which is included in the first channel setting optical signal received by the other optical transceiver, the wavelength-tunable optical receiving unit transfers the fourth channel information; the control unit sets the second channel as a channel of the optical signal to be transmitted by the wavelength-tunable optical transmission unit based on the fourth channel information transferred by the wavelength-tunable optical reception unit.

3. The optical transceiver according to claim 2.

4. the control unit controls the wavelength-tunable optical transmission unit to stop transmitting the first channel setting optical signal.

4. The optical transceiver according to claim 3.

5. the control unit, when not receiving the second channel setting optical signal, changes the channel of the first channel setting optical signal to a channel that has not yet been set as a channel of the first channel setting optical signal, and outputs the first channel setting optical signal.

5. An optical transceiver according to claim 1.

6. a first optical transmission device having a plurality of optical transceivers including a first optical transceiver, and a first optical multiplexer / demultiplexer that multiplexes and outputs optical signals output by the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels; a second optical transmission device including a plurality of optical transceivers including a second optical transceiver, and a second optical multiplexer / demultiplexer that multiplexes and outputs optical signals output by the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels; an optical cable connecting the first optical transmission device and the second optical transmission device; The first optical transceiver includes: a wavelength-tunable optical transmitter configured to be able to autonomously transmit the first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal when the first optical transceiver is attached to the first optical transmission device; a wavelength-tunable optical receiving unit that, when receiving a second channel setting optical signal from the second optical transceiver, transfers second channel information that is included in the second channel setting optical signal and indicates a channel of the second channel setting optical signal; a control unit for controlling the wavelength-tunable optical transmitter and the wavelength-tunable optical receiver, The control unit sets, based on the second channel information transferred by the wavelength-tunable optical receiving unit, a first channel indicated by the second channel information as a channel of an optical signal to be received by the wavelength-tunable optical receiving unit; the first channel setting optical signal is superimposed on the optical signal transmitted by the wavelength-tunable optical transmitter by modulating the optical signal transmitted by the wavelength-tunable optical transmitter by a phase modulation method other than an on / off modulation method that is different from a modulation method applied to a data signal; the second channel setting optical signal is superimposed on the optical signal received by the wavelength-tunable optical receiving unit by modulating the optical signal received by the wavelength-tunable optical receiving unit using a phase modulation method other than the on / off modulation method; Optical communication system.

7. A plurality of optical transceivers; an optical multiplexer / demultiplexer that multiplexes and outputs optical signals output by the plurality of optical transceivers and demultiplexes received optical signals to the plurality of optical transceivers according to channels; Each of the plurality of optical transceivers comprises: a wavelength-tunable optical transmitter configured to be capable of autonomously transmitting a first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal when the optical transceiver is attached to an optical transmission device; a wavelength-tunable optical receiving unit that, when receiving a second channel setting optical signal from another optical transceiver provided in another optical transmission device, transfers second channel information that is included in the second channel setting optical signal and indicates a channel of the second channel setting optical signal; a control unit for controlling the wavelength-tunable optical transmitter and the wavelength-tunable optical receiver, The control unit sets, based on the second channel information transferred by the wavelength-tunable optical receiving unit, a first channel indicated by the second channel information as a channel of an optical signal to be received by the wavelength-tunable optical receiving unit; the first channel setting optical signal is superimposed on the optical signal transmitted by the wavelength-tunable optical transmitter by modulating the optical signal transmitted by the wavelength-tunable optical transmitter by a phase modulation method other than an on / off modulation method that is different from a modulation method applied to a data signal; the second channel setting optical signal is superimposed on the optical signal received by the wavelength-tunable optical receiving unit by modulating the optical signal received by the wavelength-tunable optical receiving unit using a phase modulation method other than the on / off modulation method; Optical transmission equipment.

8. When attached to an optical transmission device, an optical fiber cable comprising: a first channel setting optical signal; and an optical fiber cable comprising: a first channel setting optical signal; when receiving a second channel setting optical signal from another optical transceiver, transferring second channel information included in the second channel setting optical signal, the second channel information indicating a channel of the second channel setting optical signal; Based on the transferred second channel information, set the first channel indicated by the second channel information as a channel of the optical signal to be received; the first channel setting optical signal is superimposed on the optical signal to be transmitted by modulating the optical signal to be transmitted by a phase modulation method other than an on / off modulation method, which is different from a modulation method applied to a data signal; the second channel setting optical signal is superimposed on the received optical signal by modulating the received optical signal by a phase modulation method other than the on / off modulation method; How to configure an optical transceiver.

9. An optical transceiver having a control unit configured as a calculation unit capable of controlling a wavelength tunable optical transmitter and a wavelength tunable optical receiver, a process of autonomously transmitting, when the optical transceiver is attached to an optical transmission device, the first channel setting optical signal, the first channel setting optical signal including first channel information indicating a channel of the first channel setting optical signal, from the wavelength-tunable optical transmitter; a process of transferring, when receiving a second channel setting optical signal from another optical transceiver, second channel information, which is included in the second channel setting optical signal and indicates a channel of the second channel setting optical signal, by the wavelength-tunable optical receiving unit; the control unit executes a process of setting, based on the second channel information transferred by the wavelength-tunable optical receiving unit, a first channel indicated by the second channel information as a channel of an optical signal to be received by the wavelength-tunable optical receiving unit; the first channel setting optical signal is superimposed on the optical signal transmitted by the wavelength-tunable optical transmitter by modulating the optical signal transmitted by the wavelength-tunable optical transmitter by a phase modulation method other than an on / off modulation method that is different from a modulation method applied to a data signal; the second channel setting optical signal is superimposed on the optical signal received by the wavelength-tunable optical receiving unit by modulating the optical signal received by the wavelength-tunable optical receiving unit using a phase modulation method other than the on / off modulation method; program.

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