Optical cross-connect device

Abstract

An optical cross-connect device (100) comprises: a plurality of routing units (20) connected to an optical transmission line; and a plurality of multiplexing / demultiplexing units (30) connected to the plurality of routing units (20) and accommodating transponders, wherein each of the multiplexing / demultiplexing units (30) accommodates only a user transponder (40) having the same predetermined use when resetting a path, and is connected only to the routing unit (20) required for the use. The optical cross-connect device (100) comprises: a multiplexing / demultiplexing management information DB (120) for storing the assignment between each of the multiplexing / demultiplexing units (30) and routing units (20) and the accommodated wavelength status as a multiplexing / demultiplexing management table (200); and a multiplexing / demultiplexing unit management unit (110) for selecting a multiplexing / demultiplexing unit (30), in which a transponder is to be accommodated on the basis of requirements of a service provided to a user when accommodating the transponder, on the basis of the multiplexing / demultiplexing management table (200), and assigning and connecting the selected multiplexing / demultiplexing unit (30) only to the routing unit (20) that requires the multiplexing / demultiplexing unit (30).

Description

Optical Cross-Connect Equipment

[0001] The present invention relates to an optical cross-connect device used for wavelength multiplexing transmission, which transmits wavelength multiplexed signal light, in which optical signals of a plurality of different wavelengths are multiplexed, through an optical fiber.

[0002] Conventionally, wavelength cross-connect devices are connected as relay nodes for optical signals to optical fibers of a path (optical transmission path) that bundles together multiple optical fibers in an optical network. Wavelength cross-connect devices are used, for example, in reconfigurable optical add / drop multiplexers (ROADMs) that act as path switches for optical signals transmitted using various modulation methods such as wavelength division multiplexing in optical networks. In this wavelength cross-connect device, wavelength-multiplexed signal light transmitted from an input path is output to an output path via multiple wavelength selective switches (WSSs).

[0003] A WSS is an optical switch that not only has the wavelength multiplexing / demultiplexing function of connecting input WDM (Wavelength Division Multiplexing) signals to different output ports for each wavelength, but also has the ability to change the combination of wavelength and output port.By using a WSS, on-site work is not required when changing the transmitting and receiving wavelengths, and path changes can be made quickly by remote operation.

[0004] A wavelength cross-connect device enables the switching of optical signal paths in a wavelength multiplexing transmission system. Generally, a wavelength cross-connect device is capable of switching any optical path.

[0005] FIG. 10 illustrates the node configuration of a wavelength multiplexing transmission system equipped with an optical cross-connect device. The wavelength multiplexing transmission system 1 illustrated in FIG. 10 is an optical transmission system based on Dense Wave-Division Multiplexing (DWDM), which multiplexes multiple wavelength signals onto a single optical fiber, and digital coherent technology. The wavelength multiplexing transmission system 1 includes an optical cross-connect (OXC) 10, which serves as an optical node, a transponder (TRPD) 40, and a network element operation system (NE-OpS) 50, which controls the optical cross-connect device 10. The optical cross-connect device 10 includes a route section 20 connected to a route (optical transmission path) consisting of optical fiber connecting the OXCs, and a multiplexing / demultiplexing section 30. The NE-OpS 50 is a transmission controller that monitors and controls the operation and maintenance of the optical cross-connect device 10.

[0006] The optical cross-connect device 10 transmits an optical signal of a specified wavelength to a specified path in response to an instruction from the NE-OpS 50. The optical cross-connect device 10 performs processes such as relaying optical signals between OXCs and switching the path of optical signals. The optical cross-connect device 10 is an OXC that can set the addition, separation, and passage of any optical path to multiple transmission paths. The optical cross-connect device 10 is equipped with a multiplexing / demultiplexing unit 30, which enables the addition and separation of optical paths and the addition and branching of any optical path.

[0007] The route unit 20 includes an optical amplifier 21 and a WSS 22 that switches the route of an optical signal.

[0008] The multiplexing / demultiplexing unit 30 multiplexes optical signals of different wavelengths and demultiplexes the multiplexed optical signals when adding an optical path from the transponder 40 or dropping an optical path to the transponder 40. The multiplexing / demultiplexing unit 30 is connected to the transponder 40. The multiplexing / demultiplexing unit 30 multiplexes or demultiplexes the optical signals received from the transponder 40 and outputs the multiplexed optical signals to the route unit 20.

[0009] The transponder 40 relays client signals such as GbE / 10GbE / 100GbE / 400GbE that are transmitted and received between the client and the transponder 40 via an optical transmission path such as an optical fiber. Information such as client information is superimposed on the optical signal.

[0010] Fig. 11 is a diagram showing the node configuration of a wavelength multiplexing transmission system equipped with the optical cross-connect device described in Patent Document 1. The same components as those in Fig. 10 are assigned the same reference numerals. The optical cross-connect device (OXC) 10A shown in Fig. 11 includes a WSS 23 that connects a direction unit 20 and a multiplexing / demultiplexing unit 30 by a cascade connection.

[0011] Japanese Patent Application Laid-Open No. 2019-208118

[0012] In the optical cross-connect device (OXC) 10, 10A described above, to realize the CD (Colorless, Directionless) / CDC (Colorless, Directionless, Contentionless) function, which allows remote switching of optical wavelength directions, the multiplexer / demultiplexer unit must be connected to multiple direction units. In this case, the connections between the multiplexer / demultiplexer unit and the direction units fill up the WSS ports of the direction units, limiting the number of transponders that can be connected. This poses a problem of reducing the add / drop rate (number of add / drop wavelengths or number of wavelengths accommodated in the ROADM) of a given node.

[0013] Specific issues include the following: <Optical cross-connect device 10 shown in Fig. 10> The optical cross-connect device 10 shown in Fig. 10 is unable to connect a multiplexing / demultiplexing unit or accommodate a transponder due to a lack of ports in the WSS (symbol aa in Fig. 10). That is, [number of directions - 1] are used for through-purposes, and the remainder are used for accommodating transponders, but there are cases where it is unable to connect a multiplexing / demultiplexing unit or accommodate a transponder due to a lack of ports in the WSS used for accommodating transponders.

[0014] 10, when the multiplexing / demultiplexing unit 30 is a CD / CDC compatible multiplexing / demultiplexing unit, it has connections to all of the direction units 20 in the node (symbol bb in FIG. 10), which exacerbates the shortage of WSS ports.

[0015] 11 ] The optical cross-connect device 10A shown in Fig. 11 can increase the number of transponders that can be accommodated by cascading (symbol cc in Fig. 11 ) the WSSs in the direction unit 20. However, the multi-stage WSS configuration increases the number of WSS devices between the direction unit and the multiplexing / demultiplexing unit, which increases costs and reduces reliability due to an increased failure rate.

[0016] The present invention has been made in view of the above circumstances, and has as its object to provide an optical cross-connect device that can increase the number of transponders accommodated without adding ports to the route section.

[0017] In order to solve the above-mentioned problems, an optical cross-connect device is provided which comprises a plurality of path sections connected to an optical transmission path, and a plurality of multiplexing / demultiplexing sections connected to the plurality of path sections and accommodating transponders, wherein each of the multiplexing / demultiplexing sections accommodates only the transponders intended for users with the same specified use when reconfiguring a path, and is connected only to the path sections required for that use.

[0018] According to the present invention, it is possible to provide an optical cross-connect device that can increase the number of transponders accommodated without increasing the number of ports in the route section.

[0019] 1 is a configuration diagram showing a wavelength multiplexing transmission system including an optical cross connect device according to an embodiment of the present invention. FIG. 2 is a diagram showing a multiplexing / demultiplexing management table stored in a multiplexing / demultiplexing management information DB of the optical cross connect device according to an embodiment of the present invention. FIG. 3 is a diagram showing a configuration example when a multiplexing / demultiplexing unit is added to the optical cross connect device according to an embodiment of the present invention. FIG. 4 is a diagram showing an example of a configuration when a multiplexing / demultiplexing unit is added to the optical cross connect device according to an embodiment of the present invention. FIG. 5 is a diagram showing an example of a configuration when a single-homed AWG is connected to each of the direction units of the optical cross connect device according to an embodiment of the present invention, and the remaining direction units use double homed. FIG. 6 is a diagram showing an example of a configuration when a triple-homed AWG is connected to each direction unit of the optical cross connect device according to an embodiment of the present invention. FIG. 7 is a diagram showing an example of a route change operation in a configuration when a triple-homed or more route unit is added to the optical cross connect device according to an embodiment of the present invention. FIG. 1 is a diagram showing a node configuration of a wavelength multiplexing transmission system including an optical cross-connect device described in Patent Document 1.

[0020] Hereinafter, an optical network system and the like in an embodiment for carrying out the present invention (hereinafter referred to as "the present embodiment") will be described with reference to the drawings. (First Embodiment) Fig. 1 is a configuration diagram showing the node configuration of a wavelength multiplexing transmission system equipped with an optical cross-connect device according to a first embodiment of the present invention. Components that are the same as those in Fig. 10 are assigned the same reference numerals.

[0021] 1 includes an optical cross-connect device (OXC) 100, which is an optical node, a transponder 40, and an NE-OpS 50 that controls the optical cross-connect device 100. The optical cross-connect device 100 includes route units 20A, 20B, 20C, and 20D (collectively referred to as route units 20) that are connected to the respective optical transmission paths, and a multiplexing / demultiplexing unit 30 that belongs only to the necessary route units 20 ("" indicates "and") and is arranged to connect the necessary route units 20. １－Ａ , 30１－Ｂ , 30 １－Ｃ , 30 ２－Ｄ , 30 ３－Ｅ (collectively referred to as multiplexing / demultiplexing unit 30).

[0022] [Optical Cross-Connect Device 100] As shown in FIG. 1, the optical cross-connect device 100 includes a plurality of route units 20A, 20B, 20C, and 20D connected to optical transmission lines, and a plurality of multiplexing / demultiplexing units 30 connected to the plurality of route units 20 and accommodating transponders 40. １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 ２－Ｄ , 30 ３－Ｅ and a multiplexing / demultiplexing unit management unit (110) that, based on the multiplexing / demultiplexing management information in the multiplexing / demultiplexing management information DB (120), selects a multiplexing / demultiplexing unit (30) to accommodate based on the service requirements to be provided to the user when accommodating the transponder, and causes the multiplexing / demultiplexing unit (30) to be associated with and connected only to the required path unit (20).

[0023] The NE-OpS 50 monitors and controls the operation, maintenance, etc. of the optical cross-connect device 100. The NE-OpS 50 also cooperates with the multiplexing / demultiplexing unit management unit 110 of the optical cross-connect device 100, instructs the multiplexing / demultiplexing unit management unit 110 to add multiplexing / demultiplexing units, etc., and receives multiplexing / demultiplexing management information from the multiplexing / demultiplexing unit management unit 110 to manage the transponder accommodated wavelengths.

[0024] 10, the optical cross-connect device 100 transmits an optical signal of a predetermined wavelength to a specified path in response to an instruction from the NE-OpS 50. The optical cross-connect device 10 performs processes such as relaying optical signals between OXCs and switching the path of the optical signal. The optical cross-connect device 100 is equipped with a multiplexing / demultiplexing unit 30, which enables the addition and removal of optical paths, enabling the addition and drop of any optical path.

[0025] 10 , each of the direction units 20A, 20B, 20C, and 20D includes an optical amplifier 21 and a WSS 22 that switches the optical signal direction of the direction. A single-homing (described later) AWG (Arrayed Waveguide Grating) multiplexing / demultiplexing unit 30 is connected to each direction unit 20. Using an AWG to realize a single-homing multiplexing / demultiplexing unit can realize a high-density, cost-effective optical cross-connect device, but a non-AWG multiplexing / demultiplexing unit can also be used for the single-homing multiplexing / demultiplexing unit.

[0026] Multiplexing / demultiplexing section 30 １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 ２－Ｄ , 30 ３－Ｅ 10, performs processing to multiplex optical signals of different wavelengths and demultiplex the multiplexed optical signals. １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 ２－Ｄ , 30 ３－Ｅ When accommodating a transponder, the multiplexing / demultiplexing unit 30 is arranged so as to belong (connect) only to the required path unit 20. １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 ２－Ｄ , 30 ３－Ｅ The multiplexer / demultiplexer 20 multiplexes or demultiplexes optical signals received from the transponder 40 and outputs the multiplexed or demultiplexed signals to the route units 20A, 20B, 20C, and 20D.

[0027] The transponder 40 relays client signals such as GbE / 10GbE / 100GbE / 400GbE that are transmitted and received between the client and the transponder 40 via an optical transmission path such as an optical fiber. Information such as client information is superimposed on the optical signal.

[0028] <Multiplexing / Demultiplexing Unit Management Unit 110> The multiplexing / demultiplexing unit management unit 110 refers to the multiplexing / demultiplexing management table 200 (Figure 2) in the multiplexing / demultiplexing management information DB 120, and when accommodating a transponder, selects the multiplexing / demultiplexing unit 30 to accommodate based on the service requirements to be provided to the user, and assigns (connects) the multiplexing / demultiplexing unit 30 only to the required path unit.

[0029] The multiplexing / demultiplexing unit management unit 110 is provided to address the following issues (1) and (2), and performs two management tasks: "management of the path units to which each multiplexing / demultiplexing unit belongs and the status of each wavelength accommodated," and "management of the status of wavelength accommodated by each multiplexing / demultiplexing unit."

[0030] <Expected User Conditions> The expected user conditions will be described below. The expected use case for CD / CDC flexible optical path switching is path reconfiguration, taking into account the time required for the reconfiguration. Each multiplexing / demultiplexing unit 30 accommodates only transponders 40 for users with the same predetermined purpose when reconfiguring a path, and is connected only to the path unit 20 required for that purpose. Therefore, among the predetermined purposes, the main uses can be summarized as follows:

[0031] In this embodiment, a single-destination user who does not use a backup system and a user who is switched by a higher-level device such as a router or switch are referred to as a single-destination user. In a single-destination user, a colored multiplexer / demultiplexer using an AWG is used to accommodate multiple wavelengths, thereby reducing costs.

[0032] In this embodiment, a user requesting restoration based on a pre-designed path (including a combination with switching by a higher-level device) is referred to as a dual-homed path unit. In dual-homed path units, two path units can be selected in a CD / CDC compatible multiplexing / demultiplexing unit using a WSS / MCS (Multicast Switch).

[0033] - User requesting restoration by autonomous path design In this embodiment, a user requesting restoration by autonomous path design (including combination with switching by a higher-level device) is referred to as a triple or more path unit association. In triple or more path unit association, three or more path units can be selected in a CD / CDC compatible multiplexing / demultiplexing unit using WSS / MCS. Configuration examples of single and double path unit association when the above-mentioned assumed user conditions are applied will be described later in FIG. 5. Configuration examples of triple or more path unit association will be described later in FIG. 7.

[0034] <<Problem (1)>> When adding transponders, if the number of associated directions and the number of available wavelengths are unknown when selecting an accommodated multiplexer / demultiplexer unit 30, it is difficult to select a multiplexer / demultiplexer unit 30 that meets the user's needs. To address problem (1), the multiplexer / demultiplexer unit management unit 110 manages the associated direction units for each multiplexer / demultiplexer unit and the status of each accommodated wavelength. Specifically, the multiplexer / demultiplexer unit management unit 110 selects a multiplexer / demultiplexer unit 30 that accommodates the user's wavelength based on the number of associated directions and the associated destinations of the direction units 20 of the multiplexer / demultiplexer unit 30, in accordance with the user's request to switch directions (the "expected user conditions" described above). The multiplexer / demultiplexer unit management unit 110 selects the number of associated directions and the associated destination direction unit that meets the request by referencing a multiplexer / demultiplexer management table 200 (see FIG. 2, described below).

[0035] <<Problem (2)>> If the remaining wavelengths are unknown, it is difficult to determine the timing for adding a multiplexer / demultiplexer 30 for a certain user service. To address problem (2), the multiplexer / demultiplexer management unit 110 manages the accommodated wavelength status for each multiplexer / demultiplexer. In other words, if there are no available wavelengths in multiplexers / demultiplexers that provide a unique number of wavelengths or destination path units to meet user requests, it may not be possible to accommodate a wavelength from a new user from a transponder. The multiplexer / demultiplexer management unit 110 adds multiplexers / demultiplexers to connect to each number of wavelengths or destination path units as needed, based on the availability of wavelengths accommodated in the multiplexers / demultiplexers connected to each destination path unit, as well as future demand forecasts.

[0036] <Multiplexing / Demultiplexing Management Information DB 120 and Multiplexing / Demultiplexing Management Table 200> The multiplexing / demultiplexing management information DB 120 stores the belonging direction section 20 of each multiplexing / demultiplexing unit 30 and the corresponding wavelength status, as well as the multiplexing / demultiplexing management table 200 (Figure 2) that manages the wavelength status of the multiplexing / demultiplexing unit 30.

[0037] 2 is a diagram showing a multiplexing / demultiplexing management table 200 stored in the multiplexing / demultiplexing management information DB 120. The multiplexing / demultiplexing management table 200 is a table that the multiplexing / demultiplexing unit manager 110 reads from the multiplexing / demultiplexing management information DB 120 and refers to when determining the destination of a transponder wavelength and whether to add a multiplexing / demultiplexing unit 30. The multiplexing / demultiplexing unit manager 110 refers to the multiplexing / demultiplexing management table 200 to determine the destination of a transponder wavelength and whether to add a multiplexing / demultiplexing unit 30. The multiplexing / demultiplexing management table 200 is rewritten by the multiplexing / demultiplexing unit manager 110 in response to instructions from the NE-OpS 50.

[0038] 2 has, as items (records), a multiplexing / demultiplexing unit (item) 210, an associated direction unit / ID 220, and a direction unit accommodated wavelength (bandwidth utilization rate) 230. The multiplexing / demultiplexing unit (item) 210 is configured to associate (connect) only with necessary direction units, and therefore has more detailed information, such as an associated number 211, an ID 212, and accommodated wavelength 213, and information on the corresponding direction unit to which it is associated.

[0039] In FIG. 2, the number of attributes 211 of the multiplexer / demultiplexer unit (item) 210 is assumed to be "1" to "3." Furthermore, the multiplexer / demultiplexer unit 30 with the number of attributes "1" is assigned multiplexer / demultiplexers with three IDs, with the accommodated wavelength of ID "A" being "38 / 40," the accommodated wavelength of ID "B" being "40 / 40," and the accommodated wavelength of ID "C" being "10 / 40." Furthermore, the multiplexer / demultiplexer unit 30 with the number of attributes "2" is assigned multiplexer / demultiplexers with one or more IDs, with the accommodated wavelength of ID "D" being "3 / 8." The multiplexer / demultiplexer unit 30 with the number of attributes "3" is assigned multiplexer / demultiplexers with one or more IDs, with the accommodated wavelength of ID "E" being "2 / 8."

[0040] The multiplexing / demultiplexing unit (item) 210 uniquely specifies the corresponding direction path unit / ID 220 for each ID with an attribute number of "1" to "3." In FIG. 2, the ID "A" (accommodating wavelength "38 / 40") of the multiplexing / demultiplexing unit (item) 210 with an attribute number of "1" is connected to the "direction path unit 20B (FIG. 1)" of the corresponding direction path unit / ID 220. The direction path unit accommodated wavelength (bandwidth utilization rate) 230 of the direction path unit 20B (FIG. 1) is 80%. Similarly, the ID "B" (accommodating wavelength "40 / 40") of the multiplexing / demultiplexing unit (item) 210 with an attribute number of "1" is connected to the "direction path unit 20D (FIG. 1)" (direction path unit accommodated wavelength (bandwidth utilization rate) 90%) of the corresponding direction path unit / ID 220. Furthermore, the ID "C" (accommodating wavelength "10 / 40") of the multiplexing / demultiplexing unit (item) 210 with the attribute number "1" is the "direction unit 20D (FIG. 1)" (direction unit accommodated wavelength (bandwidth utilization rate) 90%) of the attributed direction unit / ID 220. In this case, the IDs "B" and "C" of the multiplexing / demultiplexing unit (item) 210 with the attribute number "1" are both the "direction unit 20D (FIG. 1)" (direction unit accommodated wavelength (bandwidth utilization rate) 90%) of the attributed direction unit / ID 220.

[0041] Furthermore, the ID "D" (accommodating wavelength "3 / 8") of the multiplexing / splitting unit (item) 210 with the attribute number "2" is the "path unit 20A (Figure 1)" of the attributed path unit / ID 220 (path unit accommodated wavelength (bandwidth utilization rate) of path unit 20A is 40%) and the "path unit 20C (Figure 1)" of the attributed path unit / ID 220 (path unit accommodated wavelength (bandwidth utilization rate) of path unit 20C is 30%).

[0042] Furthermore, the ID "E" (accommodated wavelength "2 / 8") of the multiplexer / demultiplexer (item) 210 with the attribute number "3" is "path unit 20A (FIG. 1)" of the attributed direction unit / ID 220 (path unit accommodated wavelength (bandwidth utilization rate) of 40% for path unit 20A), "path unit 20B (FIG. 1)" of the attributed direction unit / ID 220 (path unit accommodated wavelength (bandwidth utilization rate) of 80% for path unit 20B), and "path unit 20C (FIG. 1)" of the attributed direction unit / ID 220 (path unit accommodated wavelength (bandwidth utilization rate) of 30% for path unit 20C). As described above, the multiplexer / demultiplexer management unit 110 can refer to the multiplexer / demultiplexer management table 200 (FIG. 1) so that the multiplexer / demultiplexer 30 is associated with and connected to only the necessary direction unit 20.

[0043] Here, the following is added regarding the accommodated wavelengths 213 of the multiplexing / demultiplexing unit (item) 210 in the multiplexing / demultiplexing management table 200. That is, the accommodated wavelengths 213 of the multiplexing / demultiplexing unit (item) 210 is the "number of accommodated wavelengths and the number of accommodable wavelengths" for each multiplexing / demultiplexing unit, and the number of accommodable wavelengths differs depending on the design of the multiplexing / demultiplexing unit 30.

[0044] The following is additional information regarding the wavelengths accommodated by a direction unit (bandwidth utilization rate) 230 in the multiplexing / demultiplexing management table 200. That is, the wavelengths accommodated by a direction unit (bandwidth utilization rate) 230 is the wavelength accommodation status for each direction unit 20. When the wavelength grid width is variable in a flexible grid-compatible system, the accommodation status of the direction unit is determined by the number of wavelengths regardless of the grid width, while the accommodation status of the direction unit is determined by the grid width and the number of wavelengths. Therefore, the table is described in a way that manages what percentage of the available bandwidth is occupied. Detailed accommodated wavelength bands and available wavelength bands may also be managed.

[0045] <Example of connection between the multiplexing / demultiplexing unit 30 and the direction unit 20 based on the description of the multiplexing / demultiplexing management table 200> An example of connection between the multiplexing / demultiplexing unit 30 and the direction unit 20 based on the description of the multiplexing / demultiplexing management table 200 in Fig. 2 will be described. １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 ２－Ｄ , 30 ３－Ｅ In FIG. 1, the first number in the subscript of the multiplexing / demultiplexing unit 30 represents the number of members, and the next character represents the ID of the multiplexing / demultiplexing unit 30 (the same notation is used hereinafter).

[0046] The operation of the optical cross-connect device 100 in the wavelength multiplexing transmission system 1000 configured as described above will now be described.

[0047] <Addition of Multiplexing / Demultiplexing Unit 30> Addition of a multiplexing / demultiplexing unit 30 will be described. Fig. 3 is a diagram showing an example of the configuration of the optical cross-connect device 100 when adding a multiplexing / demultiplexing unit 30, and Fig. 4 is a diagram showing an example of the description of the multiplexing / demultiplexing management table 200 when adding the multiplexing / demultiplexing unit 30 of Fig. 3. As shown in Fig. 3, the optical cross-connect device 100 is configured by adding a multiplexing / demultiplexing unit 30 with a single path unit to the configuration example of the optical cross-connect device 100 of Fig. 1. １－Ｄ (See the thick dashed lines and shading in FIG. 3 .) In the configuration example of the optical cross-connect device 100 in FIG. 3 , the multiplexing / demultiplexing management table 200 is entered as shown in FIG. 4 . That is, as shown in FIG. 4 , ID “D” (accommodating wavelength “0 / 40”) is assigned to ID 212 of the multiplexing / demultiplexing unit 210, which has an attribute number of “1,” and the direction unit 20B ( FIG. 3 ) is assigned to the associated direction unit / ID 220. The direction unit accommodated wavelength (bandwidth utilization rate) 230 of the direction unit 20B of the associated direction unit / ID 220 is 0%.

[0048] In this way, by changing the information in the multiplexing / demultiplexing management table 200, the multiplexing / demultiplexing unit 30 １－Ｄ can be added, and the multiplexing / demultiplexing unit 30 １－Ｄ By adding more transponders 40, it becomes possible to add more transponders 40.

[0049] <Configuration example of single-path unit association and double-path unit association when assumed user conditions are applied> Fig. 5 is a diagram showing a configuration example of single-path unit association and double-path unit association when assumed user conditions are applied. The same components as in Fig. 1 are given the same reference numerals. The symbol a in Fig. 5 indicates that the multiplexing / demultiplexing unit 30 cannot be connected to any more path units 20. The multiplexing / demultiplexing unit 30 shown in Fig. 5 １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 １－Ｄ is a multiplexing / demultiplexing unit with single-path connection, and a transponder 40 accommodating a user requesting single-path connection can be installed (symbol b in FIG. 5). A user requesting single-path connection is a single request that does not use a backup system, or a user switching by a higher-level device.

[0050] The multiplexing / demultiplexing unit 30 shown in FIG. ２－Ｅ , 30 ２－Ｆ is a multiplexing / demultiplexing unit with dual home positioning, and a transponder 40 accommodating a user requesting dual home positioning is installed (reference symbol c in FIG. 5). A user requesting dual home positioning is a user requesting restoration according to a pre-designed path.

[0051] In this way, the multiplexing / demultiplexing unit 30 shown in FIG. １－Ａ , 30 ２－Ｅ , the multiplexing / demultiplexing unit 30 before the expansion is shown in the box d of FIG. １－Ｂ , 30 １－Ｃ , 30 １－Ｄ , 30 ２－Ｆ The additional multiplexing / demultiplexing unit 30 １－Ｂ , 30 １－Ｃ , 30 １－Ｄ , 30 ２－Ｆ Accordingly, the number of transponders that can be accommodated can be increased.

[0052] <Specific examples of single-homing and double-homing of direction units> Figure 6 is a diagram showing a configuration example in which a single-homing AWG is connected to each direction unit 20, and the remaining units use double homing. Although not shown in Figure 6, triple or more homing is also possible. The AWG-based multiplexing / demultiplexing unit 30 is composed only of passive components and can multiplex a large number of wavelengths at low cost, making it possible to improve the wavelength accommodation rate of each direction unit 20 at low cost and in a space-saving manner.

[0053] The multiplexing / demultiplexing unit 30 shown in FIG. １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 １－Ｄ is a multiplexing / demultiplexing unit 30 with a single-direction connection (thick solid line in FIG. 6), and a transponder 40 accommodating a user who desires single connection is installed. ２－Ｅ , 30 ２－Ｆ is a multiplexing / demultiplexing unit 30 with a double-path section, and １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 １－Ｄ Further, a double-branching is added to the above, resulting in a multiplexing / branching section with double-branching (see the thick two-dot chain line and hatching in FIG. 6).

[0054] <Specific example of triple or more direction unit association: Example 1> Fig. 7 is a diagram showing a configuration example of triple or more direction unit association. Fig. 7 shows an example of triple or more direction unit association in a configuration in which multiple direction units are added between the same building and the ground. The wavelength multiplexing transmission system 1000 shown in Fig. 7 includes, in buildings A-D, and X (device installation bases), an optical cross connect device 100 and a direction 60 (optical transmission path) consisting of optical fiber or the like that connects the optical cross connect devices 100 together.

[0055] As described above in the "Expected User Conditions," the assignment of three or more path units is intended to accommodate users who require restoration through autonomous path design (including combinations with switching by higher-level devices). Furthermore, the assignment of three or more path units involves selecting three or more path units using a demultiplexer (not shown) that supports CD / CDC using WSS / MCS.

[0056] The optical cross-connect device 100 installed in buildings A-D and X shown in Fig. 7 can utilize two routes added to increase the number of wavelengths that can be accommodated in the route section. The optical cross-connect device 100 shown in Fig. 7 includes first (e.g., 0-system) route sections 20A1, 20B1, 20C1, and 20D1, second (e.g., 1-system) route sections 20A2, 20B2, 20C2, and 20D2, and a multiplexing / demultiplexing section 30. １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 １－Ｄ , 30 ４－Ｅ , 30 ４－Ｆ, 30 ４－Ｇ , 30 ４－Ｈ , a transponder 40, a multiplexing / demultiplexing unit management unit 110, and a multiplexing / demultiplexing management information DB 120.

[0057] Single-path multiplexing / demultiplexing unit 30 １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 １－Ｄ are attributed and connected only to the first path sections 20A1, 20B1, 20C1, and 20D1 (thick solid lines in FIG. 7). Although not specified, the multiplexing / demultiplexing sections with single-path connection and double-path connection may be attributed to either the first path section or the second path section.

[0058] Multiplexing / demultiplexing unit 30 with three or more path sections ４－Ｅ , 30 ４－Ｆ belong to and are connected only to the first path sections 20A1, 20B1, 20C1, and 20D1 (thick dashed lines in FIG. 7), and are not belong to and are not connected to the second path sections 20A2, 20B2, 20C2, and 20D2.

[0059] Multiplexing / demultiplexing unit 30 with three or more path sections ４－Ｇ , 30 ４－Ｈ belong to and are connected only to the second path sections 20A2, 20B2, 20C2, and 20D2 (indicated by the two-dot chain lines in FIG. 7), and are not belong to or are connected to the first path sections 20A1, 20B1, 20C1, and 20D1.

[0060] In the above configuration, the optical cross-connect device 100 installed in buildings A-D and X shown in Figure 7 assigns triple or more assignments to groups of route units between different building locations. This makes it possible to select all detour routes when viewed on a building-by-building basis. When the wavelengths in a section between a certain building and its location become full, a route unit is added to the same location. For example, as shown by the white arrow e in Figure 7, the number of wavelengths accommodated by the optical cross-connect device 100 can be increased by adding a second route unit 20A2 to a first route unit 20A1.

[0061] In this way, triple or more assignments take into account multiple route sections that have been added to increase the number of wavelengths accommodated in the same ground section, and by assigning route sections to groups of route sections for different building grounds, for example, it becomes possible to select all detour routes when viewed on a building-by-building basis.

[0062] In the example of Figure 7, if multiple sections (fibers) are constructed between the same building and the ground (between the same node and the ground), even if it is not possible to select all sections / fibers between the same building / node and the ground when selecting a detour route, it is possible to select a detour route that passes through that building / node, making it possible to select a detour route without any restrictions on the adjacent buildings / nodes that can be reached.

[0063] <Specific example of route change when three or more direction units are associated: Example 2> Figures 8 and 9 are diagrams showing an example of the operation of route change in a configuration where three or more direction units are associated. Similar to Figure 7, Figures 8 and 9 show an example of triple direction unit association in a configuration where multiple direction units are added between the same building and the ground. In Figures 8 and 9, optical cross-connect devices 100 (hereinafter referred to as nodes) are provided in buildings A-D, X, and Y (device installation bases).

[0064] As shown by symbol f in Figures 8 and 9, suppose a failure occurs in the path (optical fiber) 60 between building X and building C. The route of the optical path in Figure 8 is building X (node ​​X) → building C (node ​​C) → building Y (node ​​Y), but a detour route is set from the 0 system of building C (the thick dashed line route in Figure 8) to the 0 system of building D (the thick solid line route in Figure 8) (white arrow g in Figure 8).

[0065] In addition to the above-described Fig. 8, it is also possible to select a detour route in Fig. 9 similar to that in Fig. 8. That is, the route of the optical path in Fig. 9 is Building X (Node X) → Building C (Node C) → Building Y (Node Y), as in Fig. 8, but a detour route is set from System 1 of Building C (path indicated by the thick dashed line in Fig. 9) to System 1 of Building D (path indicated by the thick solid line in Fig. 9) (white arrow h in Fig. 9).

[0066] The examples in Figures 8 and 9 can be summarized as follows: When setting a route for an optical path that detours from Building X (Node X) → Building C (Node C) → Building Y (Node Y) to Building X (Node X) → Building C (Node D) → Building Y (Node Y), even if it is not possible to select both the section based on the route unit in Figure 8 and the section based on the route unit in Figure 9, it is possible to detour as long as one of the pairs of the same building / node can be selected.

[0067] As described above, <Example 2> is an example of route change operation in a configuration that allows selection of all detour routes when viewed on a building-by-building basis by associating three or more multiple associations for each group unit of the route section for different building-to-ground locations, similar to <Example 1> above.

[0068] In this way, when multiple sections (fibers) are constructed between the same building and the ground (between the same node and the ground), even if it is not possible to select all sections / fibers between the same building / node and the ground when selecting a detour route, it is possible to select a detour route that passes through that building / node, making it possible to select a detour route without any restrictions on the adjacent buildings / nodes that can be reached.

[0069] [Effects] As described above, the optical cross-connect device 100 (FIG. 1) comprises a plurality of path sections 20 connected to an optical transmission path, and a plurality of multiplexing / demultiplexing sections 30 connected to the plurality of path sections 20 and accommodating transponders, and each multiplexing / demultiplexing section 30 accommodates only transponders 40 intended for users with the same predetermined use when reconfiguring a path, and is connected only to the path sections 20 required for that use.

[0070] In this way, the optical cross-connect device 100 allows the multiplexing / demultiplexing unit 30 to belong to and connect only to the necessary directional units, and when accommodating a transponder, it is possible to select the accommodating multiplexing / demultiplexing unit based on the service requirements provided to the user, thereby improving the node utilization efficiency according to the service provided. As a result, the optical cross-connect device 100 can increase the number of accommodated transponders without adding any additional parts to the points where the main signal conducts (without adding ports to the directional unit).

[0071] The optical cross-connect device 100 (FIG. 1) includes a multiplexing / demultiplexing management information section (multiplexing / demultiplexing management information DB 120) that stores the assignment and accommodated wavelength status between each multiplexing / demultiplexing section 30 and each path section 20 as multiplexing / demultiplexing management information (multiplexing / demultiplexing management table 200), and a multiplexing / demultiplexing section management section 110 that, based on the multiplexing / demultiplexing management information (multiplexing / demultiplexing management table 200) in the multiplexing / demultiplexing management information section (multiplexing / demultiplexing management information DB 120), selects a multiplexing / demultiplexing section 30 to accommodate based on the service requirements to be provided to the user when accommodating a transponder, and assigns and connects the multiplexing / demultiplexing section 30 only to the required path section 20.

[0072] The optical cross-connect device 100 also executes the steps of: storing the assignment and accommodated wavelength status between each multiplexing / demultiplexing unit 30 and each path unit 20 as multiplexing / demultiplexing management information (multiplexing / demultiplexing management table 200) in the multiplexing / demultiplexing management information unit (multiplexing / demultiplexing management information DB 120); and selecting a multiplexing / demultiplexing unit 30 to accommodate based on the service requirements to be provided to the user, when accommodating a transponder, and associating and connecting the multiplexing / demultiplexing unit 30 only to the required path unit 20, based on the multiplexing / demultiplexing management information (multiplexing / demultiplexing management table 200) in the multiplexing / demultiplexing management information unit (multiplexing / demultiplexing management information DB 120).

[0073] By doing this, the optical cross-connect device 100 can manage the associated direction sections of each combining / splitting section and the wavelength status of each section, and when adding transponders, it becomes possible to make an appropriate selection when selecting the combining / splitting waves to accommodate, for example, by understanding the number of associated directions and the number of available wavelengths.

[0074] In the optical cross-connect device 100 (FIG. 1), when the number of connections between each multiplexing / demultiplexing unit and each direction unit is three or more, the connection is made as a group of direction units for different equipment installation bases (buildings). The three or more connections take into account the number of direction units for multiple systems that are added to increase the number of wavelengths accommodated in the same direction section.

[0075] In this way, the optical cross-connect device 100 can select all the detour routes when viewed on a building-by-building basis by associating each group of route sections for different building locations.

[0076] In the optical cross-connect device 100 (FIG. 1), each of the direction sections 20 is connected to a multiplexing / demultiplexing section 30 using a single-band AWG.

[0077] By doing this, the AWG multiplexing / demultiplexing section 30 is composed only of passive components and can multiplex a large number of wavelengths at low cost, making it possible to improve the wavelength accommodation rate of each route section at low cost and in a space-saving manner.

[0078] Furthermore, among the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically using known methods. In addition, the information, including the processing procedures, control procedures, specific names, various data, and parameters shown in the above documents and drawings, can be changed as desired unless otherwise specified. Furthermore, the components of each device shown in the drawings are functionally conceptual and do not necessarily have to be physically configured as shown. In other words, the specific form of distribution and integration of each device is not limited to that shown in the drawings, and all or part of the devices can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc.

[0079] Furthermore, the above-described configurations, functions, processing units, processing means, etc. may be partially or entirely implemented in hardware, for example, by designing them as integrated circuits. The above-described configurations, functions, etc. may also be implemented by software that causes a processor to interpret and execute programs that implement the respective functions. Information such as programs, tables, and files that implement the respective functions may be stored in a memory, a recording device such as a hard disk or a solid-state drive (SSD), or a recording medium such as an integrated circuit (IC) card, a secure digital (SD) card, or an optical disk.

[0080] 20, 20A, 20B, 20C, 20D Direction section 30, 30 １－Ａ , 30 １－Ｂ , 30 １－Ｃ , 30 １－Ｄ , 30 ２－Ｄ , 30２－Ｅ , 30 ２－Ｆ , 30 ３－Ｅ , 30 ４－Ｅ , 30 ４－Ｆ , 30 ４－Ｇ , 30 ４－Ｈ Multiplexing / Demultiplexing section 40 Transponder 50 NE-OpS 60 Path (optical transmission path) 100 Optical cross-connect device (OXC) 110 Multiplexing / Demultiplexing section management section 120 Multiplexing / Demultiplexing management information DB (multiplexing / Demultiplexing management information section) 200 Multiplexing / Demultiplexing management table 1000 Wavelength multiplexing transmission system A-D, X, Y Building (device installation base)

Claims

1. An optical cross-connect device comprising a plurality of path sections connected to an optical transmission line, and a plurality of multiplexing / demultiplexing sections connected to the plurality of path sections and accommodating transponders, wherein each of the multiplexing / demultiplexing sections accommodates only the transponders intended for users with the same predetermined use when reconfiguring a path, and is connected only to the path sections required for that use.

2. The optical cross-connect device according to claim 1, further comprising: a multiplexing / demultiplexing management information unit that stores the attribution and accommodated wavelength status between each multiplexing / demultiplexing unit and each path unit as multiplexing / demultiplexing management information; and a multiplexing / demultiplexing unit management unit that, based on the multiplexing / demultiplexing management information from the multiplexing / demultiplexing management information unit, selects a multiplexing / demultiplexing unit to accommodate based on the service requirements to be provided to the user when accommodating a transponder, and causes the multiplexing / demultiplexing unit to be attributable to and connected only to the necessary path units.

3. The optical cross-connect device according to claim 1, wherein when the number of connections between each multiplexing / demultiplexing unit and each direction unit is three or more, the connection is made as a group of direction units for different device installation base locations.

4. The optical cross-connect device according to claim 1 or 2, wherein a multiplexing / demultiplexing unit using a single-path AWG (Arrayed Waveguide Grating) is connected to each of said direction units.

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