Optical cross-connect switching system and switching method

Abstract

The optical cross-connect switching system and switching method of the present invention pertain to an optical cross-connect having an optical switch that can select one of a plurality of channels, using a rotary mechanism, in an optical fiber network where a first node (N1) and a second node (N2) are disposed. A first controller (CP1) of the first node (N1) receives, as a target combination, a combination of two ports selected from among optical cross-connect ports to which an optical fiber is connected and extracts a target optical switch and a target channel corresponding to the target combination. Furthermore, a control signal is output that drives the rotary mechanism of the target optical switch to select the target channel, on the basis of the current channel, which is a currently selected channel in the target optical switch, and the target channel. A second controller (CP2) of the second node (N2) receives a control signal and drives the rotary mechanism.

Description

[Technical Field]

[0001] The present disclosure relates to a switching system and a switching method for optical cross-connects. [Background technology]

[0002] Non-Patent Document 1 discloses a system that is comprised of an optical fiber network (multi-stage loop network) consisting of multiple loop networks, an optical node (in-station node) installed in an environment where commercial power can be used within a communications building, and one or more optical nodes (out-station node) installed outdoors. In the out-station node of the system, an optical switch of an optical cross-connect is controlled based on a control signal superimposed on a power supply light via an optical fiber, and the power obtained by photoelectric conversion of the power supply light is used as a power source to switch between the core wires of the optical fiber.

[0003] Non-Patent Document 2 discloses a rotating ferrule optical switch that achieves power saving and miniaturization in an optical cross-connect that switches between optical fiber cores. With this rotating ferrule optical switch, optical fibers are arranged in a circular shape in a ferrule used in an optical connector, and the rotation of the ferrule switches the channels of the optical switch, changing the connection destination of the optical fiber. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 2021 IEICE Society Conference, BK-2-3, 2021, "Remote Optical Path Switching Nodes Operating in Multistage Loop-Type Optical Access Networks" [Non-patent document 2] Institute of Electronics, Information and Communication Engineers, Optical Fiber Application Technology Study Group OFT2022-6, 2022, "Study on multi-core cylindrical ferrules for remotely controlled optical fiber rotary switches" Summary of the Invention [Problem to be solved by the invention]

[0005] According to the technology described in Non-Patent Document 1, since the off-site node is operated with low power consumption, there is a restriction that the current state of the optical switch cannot be maintained at the off-site node. Under this restriction, it is not clear what data regarding the state of the optical switch should be maintained at the on-site node. Furthermore, according to the technology described in Non-Patent Document 2, there is a problem that if a deviation occurs in the rotation direction of the ferrule when multiple switching operations are performed in a ferrule rotating optical switch, twists accumulate in the optical fiber placed in the ferrule, which may cause the optical fiber to break.

[0006] The present disclosure has been made in view of the above-mentioned problems, and aims to provide a switching system and a switching method for an optical cross-connect that can suppress deviation in the rotation direction of a rotation mechanism and suppress accumulation of twist in an optical fiber and breakage of the optical fiber even when switching is performed multiple times in an optical switch having a rotation mechanism. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, one embodiment of the present disclosure provides a switching system and a switching method for an optical cross-connect, which is provided in an optical fiber network in which a first node and a second node are located, and which includes an optical switch capable of selecting one of a plurality of channels using a rotation mechanism. A first controller of the first node receives a target combination of two ports selected from the ports of the optical cross-connect to which optical fibers are connected, and extracts a target optical switch and a target channel corresponding to the target combination. Then, based on the current channel and the target channel currently selected in the target optical switch, the first controller outputs a control signal to drive the rotation mechanism of the target optical switch to select the target channel. A second controller of the second node receives the control signal and drives the rotation mechanism. [Effects of the Invention]

[0008] According to the present disclosure, even when multiple switching operations are performed in an optical switch having a rotation mechanism, it is possible to suppress bias in the rotation direction of the rotation mechanism, and to suppress accumulation of twist in the optical fiber and breakage of the optical fiber. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a switching system according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of an optical cross-connect. [Figure 3] FIG. 3 is a diagram illustrating an example of the configuration of an optical switch. [Figure 4] FIG. 4 is a diagram illustrating an example of a setting table of the optical switch. [Figure 5] FIG. 5 is a diagram illustrating an example of a state table of the optical switch. [Figure 6] FIG. 6 is a diagram illustrating an example of a control signal table of the optical switch. [Figure 7] FIG. 7 is a diagram showing an example of a display of the connection state between ports in an optical cross-connect. [Figure 8] FIG. 8 is a flowchart showing the processing of the switching system according to an embodiment of the present disclosure. [Figure 9] FIG. 9 is a diagram illustrating a hardware configuration of the controller. DETAILED DESCRIPTION OF THE INVENTION

[0010] Next, embodiments of the present disclosure will be described in detail with reference to the drawings. In the description, the same components are designated by the same reference numerals and redundant description will be omitted.

[0011] [Switching system configuration] An example of the configuration of a switching system according to this embodiment will be described with reference to Fig. 1. As shown in Fig. 1, the switching system 1 includes an in-station controller CP1 (first controller), a database DB, and an off-station controller CP2 (second controller). In addition, the switching system 1 may include a display unit 81 and an operation unit 83.

[0012] The switching system 1 is an optical cross-connect XC switching system in an optical fiber network in which an in-station node N1 (first node) and an off-station node N2 (second node) are arranged. For example, the optical fiber network includes an upper loop LP1 and a lower loop LP2 configured by a plurality of optical fibers. The in-station node N1 is arranged in the upper loop LP1, and the off-station node N2 is arranged at a location where the upper loop LP1 and the lower loop LP2 meet. Note that the optical fiber network in which the in-station node N1 and the off-station node N2 are arranged is not limited to the above example.

[0013] Furthermore, the optical cross connect XC is placed in the off-site node N2. The optical cross connect XC has ports to which the optical fibers constituting the upper loop LP1 and the lower loop LP2 are connected. The optical cross connect XC is capable of mutually switching the optical fibers of the four-way paths (paths D1, D2, D3, and D4) included in the two loops, the upper loop LP1 and the lower loop LP2. For example, the optical fibers of the paths D1 and D2 may be optical fibers of the upper loop LP1. The optical fibers of the paths D3 and D4 may be optical fibers of the lower loop LP2.

[0014] The optical fibers switchable by the optical cross connect XC are not limited to those constituting the upper loop LP1 and the lower loop LP2. The optical cross connect XC may be capable of mutually switching optical fibers from M directions (M is an integer of 2 or more).

[0015] [Optical cross-connect configuration] As shown in Figure 2, the optical cross connect XC has ports P11, P12, P21, P22, P31, P32, P41, and P42 as ports to which optical fibers are connected. Ports P11 and P12 are connected to the optical fiber of path D1. Ports P21 and P22 are connected to the optical fiber of path D2. Ports P31 and P32 are connected to the optical fiber of path D3. Ports P41 and P42 are connected to the optical fiber of path D4.

[0016] In the above example, each route is assumed to be composed of two optical fibers, and the optical cross connect XC is assumed to have two ports for each route, for a total of eight ports, but this embodiment is not limited to this. For M routes (M is an integer of 2 or more) in each direction, if each route is composed of N optical fibers (N is an integer of 1 or more), the optical cross connect XC may have N ports for each route, for a total of "M x N" ports.

[0017] The optical cross connect XC has an optical switch for each of the above-mentioned ports. More specifically, the optical cross connect XC has optical switches SW11, SW12, SW21, SW22, SW31, SW32, SW41, and SW42 corresponding to ports P11, P12, P21, P22, P31, P32, P41, and P42, respectively. For M (M is an integer of 2 or more) directional routes, if each route is made up of N (N is an integer of 1 or more) optical fibers, the optical cross connect XC may be equipped with "M x N" optical switches.

[0018] Each optical switch is configured to be able to select one of multiple channels. The optical switches in an optical cross-connect XC are connected to other optical switches via channels. Figure 2 shows how the optical switches are connected to each other in a matrix via optical wiring paths GL beyond the channels.

[0019] Fig. 3 is a diagram showing an example of the configuration of an optical switch, showing both a cross section passing through a rotation axis AS of the optical switch and a cross section perpendicular to the rotation axis AS.

[0020] For example, as shown in Figure 3, each optical switch has six channels (channels CH1, CH2, CH3, CH4, CH5, and CH6). One optical switch has six channels for connection with other optical switches that belong to a different direction from the direction to which the port corresponding to that optical switch belongs. For M directions (M is an integer of 2 or more), if each direction is composed of N optical fibers (N is an integer of 1 or more), each optical switch may have "(M-1) x N" channels.

[0021] Each optical switch is configured to be able to select one of multiple channels using a rotation mechanism. For example, each optical switch is a multi-core cylindrical ferrule rotary optical switch. The multi-core cylindrical ferrule rotary optical switch has a multi-core cylindrical ferrule MFF in which multiple single-mode fibers are arranged as channels (channels CH1, CH2, CH3, CH4, CH5, and CH6) at the ferrule end face at the same circumferential distance from the rotation axis AS, and a single-fiber ferrule SFF in which a single-mode fiber TF is arranged at the same circumferential distance from the rotation axis AS as the single-mode fiber of the multi-core cylindrical ferrule MFF.

[0022] In each optical switch, the multiple channels may be arranged around the rotation axis AS of the rotation mechanism in the order of numbers that identify the channels. As shown in Fig. 3, in each optical switch, channels CH1, CH2, CH3, CH4, CH5, and CH6 are arranged in order around the rotation axis AS. Channels CH1, CH2, CH3, CH4, CH5, and CH6 are identified by numbers "1," "2," "3," "4," "5," and "6," respectively.

[0023] The multi-fiber cylindrical ferrule MFF and single-fiber ferrule SFF are inserted into the sleeve SB so that their end faces face each other, and a rotation mechanism is formed that switches between them by rotating either one with a motor, etc. When rotating the single-fiber ferrule SFF or multi-fiber cylindrical ferrule MFF, a gap is provided between the fiber end faces to prevent damage to the fiber end faces due to rotation.

[0024] In the example shown in Figure 3, the single-mode fiber TF of the single-fiber ferrule SFF faces the channel CH1 of the multi-core cylindrical ferrule MFF, thereby allowing communication light to be transmitted between the single-mode fiber TF and the channel CH1. When a channel of interest faces the single-mode fiber TF, the channel of interest is said to be "selected" or "to be selected." In the optical switch shown in Figure 3, channel CH1 is selected.

[0025] The channel selected by each optical switch of the optical cross-connect XC is changed by an off-site controller CP2, which will be described later. More specifically, the off-site controller CP2 drives the rotation mechanism of each optical switch so that a predetermined channel is selected.

[0026] The rotation direction of the rotation mechanism has two patterns: direction AR1 (counterclockwise direction) and direction AR2 (clockwise direction). When the channel selected in an optical switch is changed multiple times, if only one of the rotation directions, direction AR1 or direction AR2, is selected unevenly, twists will accumulate in the optical fiber. In the worst case, this may lead to breakage of the optical fiber. Therefore, when the channel selected in an optical switch with a rotation mechanism is changed multiple times, it is necessary to control it so that both direction AR1 and direction AR2 are selected as evenly as possible.

[0027] Database Configuration The database DB is connected to a first controller, which will be described later. The database DB also stores, for each combination of two ports selected from the ports of the optical cross-connect XC, a predetermined optical switch selected from the optical switches and a predetermined channel selected in the predetermined optical switch. The database DB stores, in the form of a setting table, the predetermined optical switch and the predetermined channel selected in the predetermined optical switch for each combination of two ports.

[0028] Fig. 4 is a diagram showing an example of a setting table of an optical switch. In the setting table of Fig. 4, information is stored in the format of "(A, B)" for each combination of two ports selected from the ports of the optical cross-connect XC. Here, A and B are numbers that identify a specific channel. Since the optical switch shown in Fig. 3 has six channels CH1 to CH6, A and B are integers from 1 to 6.

[0029] For example, refer to row LN and column CL in the setting table of FIG. 4. "P11" is entered in the first column of row LN, and "SW11" is entered in the second column of row LN. Therefore, it can be seen that the optical switch SW11, which is a predetermined optical switch, is stored in correspondence with port P11. "P22" is entered in the first row of column CL, and "SW22" is entered in the second row of column CL. Therefore, it can be seen that the optical switch SW22, which is a predetermined optical switch, is stored in correspondence with port P22.

[0030] Next, refer to the column where row LN and column CL intersect. This column contains "(2,1)." From this column, it can be seen that channel CH2, which is a predetermined channel, is stored in association with optical switch SW11. Furthermore, from this column, it can be seen that channel CH1, which is a predetermined channel, is stored in association with optical switch SW22.

[0031] In this way, the following can be seen from the entry "(A, B)" in the noteworthy column in the setting table of FIG. (1) The specified channel of the optical switch described in the second column of the row containing the column of interest is the channel identified by the number "A." (2) The specified channel of the optical switch listed in the second row of the column containing the column of interest is the channel identified by the number "B."

[0032] Using the configuration table in which the information is stored as described above, the database DB stores, for each combination of two ports selected from the ports of the optical cross-connect XC, a specified optical switch selected from the optical switches and a specified channel selected at the specified optical switch.

[0033] The rotation mechanism of a specified optical switch is driven by a "control signal" described later so that a specified channel is selected in the specified optical switch, resulting in two ports selected from the ports of the optical cross-connect XC being connected to each other.

[0034] Furthermore, the database DB stores, for each optical switch of the optical cross-connect XC, the channel currently selected in the optical switch as the current channel. The database DB stores the current channel in the form of a state table.

[0035] Figure 5 is a diagram showing an example of an optical switch status table. For example, referring to the row of the status table in Figure 5 where the port name is "P11," the current channel is listed as "CH1." From this entry, it can be seen that the channel currently selected in the optical switch SW11 corresponding to port P11 is channel CH1.

[0036] Every time the channel selected in the optical switch is changed, the information about the current channel stored in the status table is changed based on a command from the in-house controller CP1, which will be described later.

[0037] Alternatively, the database DB may store the predetermined rotation direction and predetermined rotation amount of the rotation mechanism in the target optical switch for each combination of the current channel and the target channel corresponding to the target optical switch. The database DB stores the predetermined rotation direction and predetermined rotation amount of the rotation mechanism in the form of a control signal table. The database DB may store a control signal table for each optical switch included in the optical cross-connect XC.

[0038] Fig. 6 is a diagram showing an example of a control signal table of an optical switch. In the control signal table of Fig. 6, channels CH1 to CH6 are shown as "current channels" that may be selected, and channels CH1 to CH6 are shown as "target channels" that may be selected.

[0039] The numerical entries in the control signal table indicate the predetermined rotation direction and predetermined rotation amount of the rotation mechanism required to change the state in which the "current channel" is selected in the optical switch to the state in which the "target channel" is selected. For example, the entry "+K" (K is an integer greater than or equal to 1) indicates that the rotation direction of the rotation mechanism of the optical switch is direction AR1, and the rotation amount is "K". The entry "-K" (K is an integer greater than or equal to 1) indicates that the rotation direction of the rotation mechanism of the optical switch is direction AR2, which is opposite to direction AR1, and the rotation amount is "K". The entry "0" indicates that the rotation amount of the rotation mechanism is 0.

[0040] In the control signal table, the number found by subtracting the number identifying the "current channel" from the number identifying the "target channel" is the number entered in the control signal table. For example, the number in the column where the "current channel" is "channel CH1" in the column where the "target channel" is "channel CH3" is "+2." This corresponds to the result of the calculation "3 - 1 = 2."

[0041] Because the numbers in the control signal table are preset in this way, bias in the rotation direction of the rotation mechanism is suppressed even when the off-site controller CP2 (described later) drives the rotation mechanism to switch the optical switch multiple times. For example, consider a case where an optical switch whose "current channel" is "channel CH6" is switched to "channel CH1" adjacent to "channel CH6." In this case, because of the setting of the numbers in the control signal table described above, the optical switch does not rotate by one channel from "channel CH6" toward "channel CH1." Instead, it rotates by five channels in the opposite direction, suppressing bias in the rotation direction of the rotation mechanism. In other words, the rotation mechanism rotates in a direction that suppresses twisting so that the twist in the optical fiber does not exceed a predetermined amount.

[0042] [In-house controller configuration] The on-site controller CP1 (an example of a control unit or a processing unit) is a general-purpose computer equipped with a CPU (Central Processing Unit), a memory, and an input / output unit. A computer program (switching program) is installed in the on-site controller CP1 to cause it to function as part of the switching system 1. By executing the computer program, the on-site controller CP1 functions as an information processing circuit that realizes multiple functions described below.

[0043] It is also possible to configure the information processing circuit by preparing dedicated hardware for executing each of the information processes described below. Also, multiple information processing circuits may be configured with individual hardware.

[0044] First, the local office controller CP1 receives a combination of two ports selected from the ports of the optical cross-connect XC as a target combination. For example, the local office controller CP1 may be connected to an operation unit 83 through which a user inputs an operation, and may acquire the target combination based on the user's operation. Alternatively, the local office controller CP1 may receive the target combination transmitted from an external management server or the like.

[0045] In the following description, it is assumed that the in-house controller CP1 has acquired the combination of "port P11, port P22" as the target combination.

[0046] Furthermore, the in-house controller CP1 refers to the database DB and extracts a predetermined optical switch and a predetermined channel corresponding to the target combination as a target optical switch and a target channel, respectively.

[0047] When the target combination is "port P11, port P22," the local office controller CP1 refers to row LN and column CL in the setting table shown in Fig. 4. Then, the local office controller CP1 extracts "optical switch SW11" as the target optical switch based on row LN, and extracts "optical switch SW22" as the target optical switch based on column CL. In the setting table, the column where row LN and column CL intersect has "(2, 1)" written, and based on this, the local office controller CP1 extracts "channel CH2" as the target channel for "optical switch SW11" and "channel CH1" as the target channel for "optical switch SW22."

[0048] Furthermore, the central office controller CP1 generates a control signal for driving the rotation mechanism of the target optical switch to select the target channel, based on the current channel and the target channel corresponding to the target optical switch. In particular, the central office controller CP1 may generate a control signal for specifying the rotation direction and the rotation amount of the rotation mechanism in the target optical switch, based on the current channel and the target channel corresponding to the target optical switch.

[0049] When the target combination is "port P11, port P22," the local controller CP1 refers to the row with the port name "P11" and the row with the port name "P22" in the state table shown in Fig. 5. Then, based on the row with the port name "P11," the local controller CP1 extracts that the current channel of "optical switch SW11" is "channel CH1." Furthermore, based on the row with the port name "P22," the local controller CP1 extracts that the current channel of "optical switch SW22" is "channel CH5."

[0050] From the above, it can be seen that for the target optical switch "optical switch SW11," the current channel "channel CH1" should be changed to the target channel "channel CH2." Also, it can be seen that for the target optical switch "optical switch SW22," the current channel "channel CH5" should be changed to the target channel "channel CH1."

[0051] Here, the on-site controller CP1 may refer to the database DB to extract a predetermined rotation direction and a predetermined rotation amount corresponding to the combination of the current channel and the target channel corresponding to the target optical switch, and set the extracted predetermined rotation direction and predetermined rotation amount as the rotation direction and rotation amount of the rotation mechanism in the target optical switch, respectively.

[0052] When the target combination is "port P11, port P22," the local controller CP1 refers to the control signal table shown in Figure 6 and extracts "+1" for "optical switch SW11" and "-4" for "optical switch SW22." Therefore, the local controller CP1 sets the rotation direction of "optical switch SW11" to "direction AR1" and the rotation amount to "1" (the angle amount for one channel) for "optical switch SW11." Furthermore, the local controller CP1 sets the rotation direction of "optical switch SW22" to "direction AR2" and the rotation amount to "4" (the angle amount for four channels) for "optical switch SW22."

[0053] Alternatively, the local office controller CP1 may set the rotation direction and rotation amount of the rotation mechanism in the target optical switch by calculation, instead of referring to the database DB. More specifically, the local office controller CP1 may calculate the difference between a first number identifying the current channel corresponding to the target optical switch and a second number identifying the target channel. The local office controller CP1 may then set the rotation direction so that the rotation direction set when the difference is negative is opposite to the rotation direction set when the difference is positive, and set the rotation amount based on the difference.

[0054] When the target combination is "port P11, port P22," the local office controller CP1 calculates the difference between the first number "1" identifying the current channel "channel CH1" and the second number "2" identifying the target channel "channel CH2" for the target optical switch "optical switch SW11," and obtains "+1." Then, the local office controller CP1 may set the rotation direction of the "optical switch SW11" to "direction AR1" and the rotation amount to "1" (the angle amount for one channel).

[0055] Furthermore, the local office controller CP1 calculates the difference between the first number "5" identifying the current channel "channel CH5" and the second number "1" identifying the target channel "channel CH1" for the "optical switch SW22" that is the target optical switch, and obtains "-4." The local office controller CP1 may then set the rotation direction of the "optical switch SW22" to "direction AR2" and the rotation amount to "4" (an angle amount for four channels).

[0056] After a control signal for driving the rotation mechanism of the target optical switch to select the target channel is generated, the on-site controller CP1 outputs the control signal to the off-site node N2 via the on-site node N1. The control signal may be transmitted from the on-site node N1 to the off-site node N2 via an optical fiber between the on-site node N1 and the off-site node N2. Alternatively, the control signal may be transmitted from the on-site node N1 to the off-site node N2 via a wired network such as a metal wire, a wireless network, or a network that combines these, other than an optical fiber.

[0057] Alternatively, the in-house controller CP1 may store the target channel in the database DB as the current channel of the target optical switch after outputting the control signal.

[0058] When the target combination is "port P11, port P22," the local controller CP1 sends a command to the database DB to change the current channel of "optical switch SW11" from "channel CH1" to "channel CH2." Also, the local controller CP1 sends a command to the database DB to change the current channel of "optical switch SW22" from "channel CH5" to "channel CH1."

[0059] [Outside controller configuration] The off-site controller CP2 (an example of a control unit or a processing unit) is operated by optical power supplied from the on-site node N1 to the off-site node N2. For example, the off-site controller CP2 may be configured with dedicated hardware to achieve power saving. Alternatively, the off-site controller CP2 may be configured with a general-purpose computer equipped with a CPU (Central Processing Unit), memory, and input / output units.

[0060] The off-site controller CP2 of the off-site node N2 receives the control signal transmitted from the on-site controller CP1. The off-site controller CP2 is connected to each optical switch provided in the optical cross-connect XC so as to drive the rotation mechanism of each optical switch. When the off-site controller CP2 receives the control signal, the off-site controller CP2 drives the rotation mechanism of each optical switch so that a predetermined channel is selected.

[0061] [Others, configuration of the operation unit and display unit] The display unit 81 is connected to the in-house controller CP1 and displays the target combination based on a command from the in-house controller CP1. Alternatively, the display unit 81 may display the connection status between ports in the optical cross-connect XC.

[0062] The display unit 81 is not limited to a unit that presents various types of information visually. The display unit 81 may present information to the user through auditory information, or may generate vibrations to present information to the user through vibration stimulation.

[0063] 7 is a diagram showing an example of a display of the connection state between ports in an optical cross connect. For example, the display unit 81 may display the ports of the optical cross connect XC by grouping them according to the paths to which the connected optical fibers belong.

[0064] 7, ports P11 and P12 are displayed in a frame corresponding to path D1. Ports P21 and P22 are displayed in a frame corresponding to path D2. Ports P31 and P32 are displayed in a frame corresponding to path D3. Ports P41 and P42 are displayed in a frame corresponding to path D4. This allows the user to intuitively recognize which path each port in the optical cross connect XC corresponds to.

[0065] 7, a thick line is displayed connecting the display of port P11 and the display of port P32, indicating that port P11 and port P32 are connected. Similarly, it is displayed that port P12 and port P31 are connected. It is displayed that port 21 and port P41 are connected. It is displayed that port 22 and port P42 are connected. This allows the user to intuitively recognize the connection status between ports in the optical cross-connect XC.

[0066] The operation unit 83 is connected to the in-station controller CP1 and acquires a target combination. The acquired target combination is transmitted to the in-station controller CP1. In addition, the operation unit 83 accepts user operations corresponding to various commands from the user to the switching system 1. For example, the operation unit 83 may be an input interface having a plurality of buttons, or may be a touch panel having a touch interface.

[0067] More specifically, the display unit 81 may display icons represented by pictures or symbols so that the user can operate them, and the operation unit 83 may accept user operations by the user touching, dragging, etc. the displayed icons.

[0068] For example, if the optical cross-connect XC includes ports P11 to P14, P21 to P24, P31 to P34, and P41 to P44, the display unit 81 may display buttons B11 to B14, B21 to B24, B31 to B34, and B41 to B44 corresponding to the respective ports. Furthermore, the display unit 81 may display a button B01 labeled "Connect" and a button B02 labeled "Release." The operation unit 83 may accept operations in which the user presses various buttons.

[0069] For example, the user may input a command to disconnect the connection between port P11 and port P32 by pressing button B11 or button B32 displayed on display unit 81, and then pressing button B02 labeled "Disconnect."

[0070] Furthermore, the user may input "port P11, port P22" as the target combination by pressing button B01 labeled "connect" after pressing buttons B11 and B22 displayed on the display unit 81. In other words, the operation unit 83 may receive a command to connect port P11 and port P22.

[0071] [Switching system processing procedure] Next, the processing procedure of the switching system according to this embodiment will be described with reference to the flowchart of Fig. 8. Fig. 8 is a flowchart showing the processing of the switching system according to this embodiment.

[0072] In step S101, the central office controller CP1 receives a combination of two ports selected from the ports of the optical cross-connect XC as a target combination.

[0073] In step S103, the in-house controller CP1 refers to the database DB and extracts a predetermined optical switch and a predetermined channel corresponding to the target combination as a target optical switch and a target channel, respectively.

[0074] In step S105, the central office controller CP1 sets the rotation direction and rotation amount of the rotation mechanism in the target optical switch.

[0075] In step S107, the in-house controller CP1 generates a control signal that specifies the direction and amount of rotation of the rotation mechanism in the target optical switch.

[0076] In step S109, the in-house controller CP1 outputs a control signal.

[0077] In step S111, the off-site controller CP2 receives the control signal.

[0078] In step S113, the off-site controller CP2 drives the rotation mechanism of each optical switch based on the control signal so that a predetermined channel is selected.

[0079] In step S115, the local controller CP1 updates the current channel stored in the database DB.

[0080] [Effects of the embodiment] As described above in detail, the optical cross-connect switching system and switching method according to the present embodiment relate to an optical cross-connect switching system in an optical fiber network in which a first node and a second node are arranged. The switching system includes a first controller, a database, and a second controller.

[0081] The optical cross connect is arranged at the second node and has ports to which optical fibers are connected, and for each port, has an optical switch that can select one of multiple channels using a rotation mechanism, and the optical switch is connected to other optical switches via the channel. The database is connected to the first controller and stores, for each combination of two ports selected from the ports, a predetermined optical switch selected from the optical switches and a predetermined channel selected in the predetermined optical switch, and for each optical switch, stores the channel currently selected in the optical switch as a current channel.

[0082] The first controller receives a combination of two ports selected from the ports as a target combination, refers to a database, extracts a predetermined optical switch and a predetermined channel corresponding to the target combination as a target optical switch and a target channel, respectively, generates a control signal for driving a rotation mechanism of the target optical switch to select the target channel based on the current channel and target channel corresponding to the target optical switch, and outputs the control signal to the second node via the first node.The second controller then receives the control signal and drives the rotation mechanism.

[0083] This allows data regarding the status of the optical switches that make up the optical cross-connect to be stored at the in-house node, and even when multiple switching operations are performed in an optical switch having a rotation mechanism, it is possible to suppress bias in the rotation direction of the rotation mechanism, thereby suppressing the accumulation of twist in the optical fiber and the breakage of the optical fiber.

[0084] In particular, when an off-site node is operated using power supply light supplied from an on-site node to the off-site node, even if the current state of the optical switch cannot be maintained at the off-site node in order to operate the off-site node with low power consumption, accumulation of twists in the optical fiber and breakage of the optical fiber can be suppressed.

[0085] In the optical cross-connect switching system and switching method according to the present embodiment, the first controller may generate a control signal that specifies the direction and amount of rotation of the rotation mechanism in the target optical switch based on the current channel and the target channel corresponding to the target optical switch. This allows the optical switch to switch to a specified channel with high accuracy. Furthermore, accumulation of twist in the optical fiber can be suppressed.

[0086] Furthermore, in the optical cross-connect switching system and switching method according to this embodiment, the database may store a predetermined rotation direction and a predetermined rotation amount of the rotation mechanism in the target optical switch for each combination of a current channel and a target channel corresponding to the target optical switch. The first controller may refer to the database to extract the predetermined rotation direction and predetermined rotation amount corresponding to the combination of the current channel and the target channel corresponding to the target optical switch, and set the extracted predetermined rotation direction and predetermined rotation amount as the rotation direction and rotation amount of the rotation mechanism in the target optical switch, respectively. This allows the optical switch to switch to the specified channel with high accuracy. Furthermore, accumulation of twist in the optical fiber can be suppressed.

[0087] Furthermore, in the optical cross-connect switching system and switching method according to this embodiment, the multiple channels of the optical switch may be arranged around the rotation axis of the rotation mechanism in the order of numbers identifying the channels. The first controller may calculate a difference between a first number identifying a current channel corresponding to the target optical switch and a second number identifying the target channel, and set a rotation direction such that the rotation direction set when the difference is positive is opposite to the rotation direction set when the difference is negative, and set the rotation amount based on the difference. This allows the optical switch to switch to the specified channel with high accuracy. Furthermore, accumulation of twist in the optical fiber can be suppressed.

[0088] Furthermore, in the optical cross-connect switching system and switching method according to the present embodiment, the first controller may store the target channel in the database as the current channel of the target optical switch after outputting the control signal. This allows the current state of the optical switch to be maintained at the on-site node N1. As a result, even under the constraint that the state cannot be maintained at an off-site node, accumulation of twist in the optical fiber and breakage of the optical fiber can be suppressed.

[0089] In the optical cross-connect switching system and switching method according to the present embodiment, the first controller may acquire the target combination via an operation unit. This allows the user to easily change the connection state between ports in the optical cross-connect XC. As a result, the user's convenience when using the switching system is improved.

[0090] Furthermore, in the optical cross-connect switching system and switching method according to the present embodiment, the first controller may display the connection status between ports of the optical cross-connect via a display unit. This allows a user to intuitively recognize the connection status between ports in the optical cross-connect XC. As a result, the convenience for the user when using the switching system is improved.

[0091] [others] The on-site controller CP1 and off-site controller CP2 described above can be realized, for example, by using a general-purpose computer system including a CPU 901, a memory 902, a storage 903, a communication device 904, an input device 905, and an output device 906, as shown in Fig. 9. The memory 902 and the storage 903 are storage devices. In this computer system, the CPU 901 executes a predetermined program loaded onto the memory 902, thereby realizing the functions of the on-site controller CP1 and the off-site controller CP2.

[0092] The on-site controller CP1 and the off-site controller CP2 may be implemented in one computer. The on-site controller CP1 and the off-site controller CP2 may be implemented in multiple computers. The on-site controller CP1 and the off-site controller CP2 may be virtual machines implemented in a computer. The programs for the on-site controller CP1 and the off-site controller CP2 may be stored in a computer-readable recording medium such as an HDD, SSD, USB memory, CD, or DVD. The computer-readable recording medium is, for example, a non-transitory recording medium. The programs for the on-site controller CP1 and the off-site controller CP2 may also be distributed via a communication network.

[0093] Each function described in the above embodiments may be implemented by one or more processing circuits, including programmed processors, electrical circuits, and even devices such as application specific integrated circuits (ASICs), circuit components arranged to perform the described functions.

[0094] Although the contents of the present disclosure have been described above based on the embodiments, the present disclosure is not limited to these descriptions, and various modifications and improvements are possible, which will be apparent to those skilled in the art. The descriptions and drawings that form part of this disclosure should not be understood as limiting the present disclosure. Various alternative embodiments, examples, and operating techniques will be apparent to those skilled in the art from this disclosure.

[0095] Of course, the present disclosure includes various embodiments not described herein. Therefore, the technical scope of the present disclosure is defined only by the invention-specifying matters according to the scope of the claims that are appropriate from the above description. [Explanation of symbols]

[0096] 1 Switching System 81 Display section 83 Operation section CH1~CH6 channels CP1 Station Controller (1st Controller) CP2 Outside controller (second controller) DB Database N1 Internal node (first node) N2 Off-site node (second node) P11, P12, P21, P22, P31, P32, P41, P42 ports SW11,SW12,SW21,SW22,SW31,SW32,SW41,SW42 Optical switch XC Optical Cross Connect

Claims

1. An optical cross-connect switching system in an optical fiber network in which a first node and a second node are arranged, A first controller, a database, and a second controller, The optical cross connect comprises: Located at the second node, a port to which an optical fiber is connected; an optical switch for each of the ports that can select one of a plurality of channels by a rotation mechanism; The optical switch is connected to another optical switch via the channel, The database comprises: connected to the first controller; storing a predetermined optical switch selected from the optical switches and a predetermined channel selected in the predetermined optical switch for each combination of two ports selected from the ports; for each of the optical switches, storing the channel currently selected at the optical switch as a current channel; The first controller receiving a combination of two ports selected from the ports as a target combination; extracting the predetermined optical switch and the predetermined channel corresponding to the target combination as a target optical switch and a target channel, respectively, by referring to the database; generating a control signal for driving the rotation mechanism of the target optical switch to select the target channel based on the current channel and the target channel corresponding to the target optical switch; outputting the control signal to the second node via the first node; The second controller receiving the control signal to drive the rotation mechanism; A switching system characterized by:

2. The first controller generating the control signal that specifies the rotation direction and rotation amount of the rotation mechanism in the target optical switch based on the current channel and the target channel corresponding to the target optical switch; 2. The switching system according to claim 1, wherein:

3. The database comprises: storing a predetermined rotation direction and a predetermined rotation amount of the rotation mechanism in the target optical switch for each combination of the current channel and the target channel corresponding to the target optical switch; The first controller extracting the predetermined rotation direction and the predetermined rotation amount corresponding to the combination of the current channel and the target channel corresponding to the target optical switch by referring to the database; setting the extracted predetermined rotation direction and predetermined rotation amount as the rotation direction and the rotation amount of the rotation mechanism in the target optical switch, respectively; 3. The switching system according to claim 2, wherein:

4. In the optical switch, the plurality of channels are arranged around the rotation axis of the rotation mechanism in the order of numbers identifying the channels; The first controller Calculating a difference between a first number identifying the current channel corresponding to the target optical switch and a second number identifying the target channel; setting the rotation direction such that the rotation direction set when the difference is negative is opposite to the rotation direction set when the difference is positive; setting the rotation amount based on the difference; 3. The switching system according to claim 2, wherein:

5. The first controller After outputting the control signal, storing the target channel in the database as the current channel of the target optical switch. The switching system according to any one of claims 1 to 4, characterized in that

6. The switching system further includes an operation unit, The first controller acquires the target combination via the operation unit. The switching system according to any one of claims 1 to 4, characterized in that

7. The switching system further includes a display unit, The first controller displays a connection state between the ports of the optical cross connect via the display unit. The switching system according to any one of claims 1 to 4, characterized in that

8. 1. A method for switching an optical cross-connect in an optical fiber network in which a first node and a second node are arranged, comprising: A switching system including a first controller, a database, and a second controller, The optical cross connect comprises: Located at the second node, a port to which an optical fiber is connected; an optical switch for each of the ports that can select one of a plurality of channels by a rotation mechanism; The optical switch is connected to another optical switch via the channel, The database comprises: connected to the first controller; storing a predetermined optical switch selected from the optical switches and a predetermined channel selected in the predetermined optical switch for each combination of two ports selected from the ports; for each of the optical switches, storing the channel currently selected at the optical switch as a current channel; The first controller receiving a combination of two ports selected from the ports as a target combination; extracting the predetermined optical switch and the predetermined channel corresponding to the target combination as a target optical switch and a target channel, respectively, by referring to the database; generating a control signal for driving the rotation mechanism of the target optical switch to select the target channel based on the current channel and the target channel corresponding to the target optical switch; outputting the control signal to the second node via the first node; The second controller receiving the control signal to drive the rotation mechanism; A switching method characterized by the above.

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