Optical network management device and optical network management method

Abstract

To reduces the design load in optical path accommodation design.SOLUTION: An optical network management device for managing an optical network in which a plurality of unit optical networks are optically connected includes acquisition means for acquiring, when a request is made to add another unit optical network different from any of the plurality of unit optical networks to the optical network, the first channel number from setting information including the first channel number of the first optical channels used between the unit optical networks and the second channel number of the second optical channels used in each unit optical network, and reservation means for releasing some of the already reserved optical channels from the DB and allocating the reservation of the first optical channel group to the vacant space in the DB after the release when there is no vacant space in the DB managing the plurality of optical channels used in the optical network before a first optical channel group corresponding to the number of first channels used between each of the plurality of unit optical networks and another unit optical network is reserved.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to an optical network management device and an optical network management method. [Background technology]

[0002] Optical networks are known in which multiple nodes are connected in a ring or mesh topology via optical fibers. One example of a node is a reconfigurable optical add / drop multiplexer (ROADM). A huge number of optical paths are established and accommodated within an optical network. An optical path is a series of communication routes connecting a start node and a finish node within the optical network. In optical network design, the wavelength of an optical signal is assigned to each optical path within the optical network (see, for example, Patent Document 1).

[0003] Various methods have been proposed for setting up optical paths. For example, a method has been proposed in which, each time a request for setting up an optical path is made, an available route and available wavelength for opening an optical path are searched for, the impact of transmission degradation factors of the available route on communication quality is evaluated, and an optical path is set up if transmission characteristics can be maintained. Known transmission degradation factors include PMD (Polarization Mode Dispersion) (see, for example, Patent Document 2).

[0004] Also proposed is a method of allocating and reserving routes and wavelengths based on a demand plan before a wavelength opening request is made, and allocating optical paths based on the design results (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-039208 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-199891 [Patent Document 3] Japanese Patent Application Laid-Open No. 2011-023981 Summary of the Invention [Problem to be solved by the invention]

[0006] In the design work of accommodating optical paths in an optical network (hereinafter referred to as optical path accommodation design), the optical paths are designed based on a demand forecast in advance. However, there are cases where the optical paths designed based on the demand forecast deviate from the actual optical paths when the optical paths are opened.

[0007] For example, there are cases where the actual number of optical paths exceeds the demand plan. In this case, a new node is added to the existing optical network. There are also cases where the actual number of optical paths greatly exceeds the demand plan. In this case, a new optical network is added to the existing optical network. When such a scale-out (expansion) of the optical network occurs, it is necessary to redesign the optical paths across the entire optical network. When a redesign of the optical paths occurs, there is a possibility that the design load will increase.

[0008] Therefore, one object of the present invention is to provide an optical network management device and an optical network management method that reduce the design load in optical path accommodation design. [Means for solving the problem]

[0009] In one embodiment, the optical network management device is an optical network management device that manages an optical network in which a plurality of unit optical networks are optically connected, and when a request is made to add another unit optical network different from any of the plurality of unit optical networks to the optical network, the optical network management device has: an acquisition means that acquires the first channel number from configuration information including a first channel number of first optical channels used between the plurality of unit optical networks and a second channel number of second optical channels used within each unit optical network belonging to the optical network; a determination means that determines whether there is space in a database managing the plurality of optical channels used in the optical network before a number of first optical channel groups corresponding to the first channel number used between each of the plurality of unit optical networks and the other unit optical network are reserved; and a reservation means that, if there is no space in the database, releases from the database some of the already reserved specified optical channels and allocates the reservation of the first optical channel group to the space in the database after some of the specified optical channels have been released. [Effects of the Invention]

[0010] This reduces the design load in optical path accommodation design. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an example of an APN (All Photonics Network). [Figure 2] FIG. 2 is a block diagram illustrating an example of a hardware configuration of an optical network controller. [Figure 3] FIG. 2 is a block diagram illustrating an example of a functional configuration of an optical network controller. [Figure 4] FIG. 10 is a diagram illustrating an example of the configuration of a channel management table. [Figure 5] FIG. 10 is a diagram illustrating an example of a transition of a channel management table. [Figure 6]FIG. 10 is a diagram illustrating an example of an APN in which an optical path is accommodated. [Figure 7] 10 is a flowchart illustrating an example of a first operation of the optical network controller. [Figure 8] FIG. 10 is a diagram illustrating an example of a channel management table. [Figure 9] FIG. 10 is a diagram illustrating another example of an APN in which an optical path is accommodated. [Figure 10] FIG. 10 is a diagram illustrating another example of a channel management table. [Figure 11] 10 is a part of a flowchart illustrating an example of a second operation of the optical network controller. [Figure 12] 10 is the remainder of the flowchart illustrating an example of the second operation of the optical network controller. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] 1, the APN 50 includes PDNs (Photonics Domain Networks) 10 and 20 and a PCN (Photonics Core Network) 40. The PDNs 10 and 20 and the PCN 40 are all examples of unit optical networks.

[0014] The PDN 10 includes, for example, an optical metro network. The PDN 10 may include an optical access network instead of or in addition to the optical metro network. The PDN 20 has basically the same network configuration as the PDN 10, except that it is operated by a different telecommunications carrier, and therefore a detailed description thereof will be omitted.

[0015] The PDN 10 includes a plurality of nodes 11, 12, 13, 14, and 15, such as ROADMs. The ROADM described in this embodiment does not include a transponder that converts between optical and electrical signals, but includes a WSS (Wavelength Selective Switch). Therefore, each of the plurality of nodes 11, 12, 13, 14, and 15 outputs an input optical signal without converting the wavelength of the input optical signal. The node 11 is connected to a mobile base station 16 via an optical transmission path F1 such as an optical fiber. Any of the nodes 12, 13, 14, and 15 may be connected to the mobile base station 16.

[0016] Similarly, PDN 20 includes multiple nodes 21, 22, 23, 24, and 25. Node 21 is connected to mobile base station 26 via optical transmission path F2. Node 25 is connected to mobile base station 27 via optical transmission path F3. Any of nodes 22, 23, and 24 may be connected to any of mobile base stations 26 and 27.

[0017] Nodes 11, 12, 13, 14, and 15 are connected in a ring configuration by optical transmission line F4. For example, node 12 is connected to nodes 11 and 13 adjacent to node 12. Nodes 11, 12, 13, 14, and 15 may also be connected in a mesh configuration by optical transmission line F4. In this case, node 12 is connected not only to nodes 11 and 13 adjacent to node 12, but also to nodes 14 and 15 that are not adjacent to node 12.

[0018] Similarly, nodes 21, 22, 23, 24, and 25 are connected in a ring configuration via optical transmission line F5. Nodes 21, 22, 23, 24, and 25 may also be connected in a mesh configuration via optical transmission line F5. Nodes 11, 12, 13, 14, and 15 may also be connected in a linear configuration via optical transmission line F4. Nodes 21, 22, 23, 24, and 25 may also be connected in a linear configuration via optical transmission line F5.

[0019] An optical path is set between nodes 11, 12, 13, 14, and 15 by an NMS (Network Management System) 19. An optical path that is completed within PDN 10 is set by NMS 19. Similarly, an optical path is set between nodes 21, 22, 23, 24, and 25 by NMS 29. An optical path that is completed within PDN 20 is set by NMS 29.

[0020] Like the PDNs 10 and 20, the PCN 40 includes multiple nodes 41, 42, and 43. In the PCN 40, nodes 14 and 24 are shared as POIs (Points of Interface). Therefore, the PCN 40 may include the nodes 14 and 24. The nodes 14, 24, 41, 42, and 43 are connected in a ring topology by the optical transmission line F6. For example, the node 14 is connected to the nodes 41 and 43 adjacent to the node 14. The nodes 14, 24, 41, 42, and 43 may also be connected in a mesh topology by the optical transmission line F6.

[0021] Nodes 41, 42, and 43 are directly monitored and controlled by optical network controller 100. Optical network controller 100 is an example of an optical network management device. Node 14 is indirectly monitored and controlled by optical network controller 100 via NMS 19. Node 14 may also be directly monitored and controlled by optical network controller 100. Similarly, node 24 is indirectly monitored and controlled by optical network controller 100 via NMS 29. Node 24 may also be directly monitored and controlled by optical network controller 100.

[0022] In this way, the APN 50 optically connects the PDN 10 and the PCN 40. Therefore, no optical signal to electrical signal conversion is performed between the PDN 10 and the PCN 40, and the optical signal is transmitted as an optical signal. Similarly, the APN 50 optically connects the PDN 20 and the PCN 40. Therefore, no optical signal to electrical signal conversion is performed between the PDN 20 and the PCN 40, and the optical signal is transmitted as an optical signal. This allows the optical network controller 100 to collectively manage the optical paths accommodated in the APN 50.

[0023] Furthermore, in this embodiment, neither nodes 11, . . . , 25 nor nodes 41, 42, 43 perform wavelength conversion of the input optical signal, and an optical signal with the same wavelength as the wavelength of the input optical signal is output. For example, an optical path with node 11 as the start node and node 25 as the end node may be set and accommodated in APN 50. In this case, optical signals of the same wavelength are transmitted end-to-end using that optical path as a communication route. Note that optical paths are allocated in APN 50 for each optical communication service. For this reason, as the number of optical communication services increases, a huge number of optical paths will require wavelengths.

[0024] On the other hand, constraints are required for the accommodation of optical paths and the selection of wavelengths to avoid collisions between wavelengths. Thus, neither nodes 11, . . . , 25 nor nodes 41, 42, 43 perform optical signal regeneration using electrical signals, nor wavelength conversion. If optical signal regeneration is not performed, degradation of the signal quality of the optical signal accumulates, limiting the transmittable distance of the optical signal. In other words, it is required to accommodate optical paths that not only avoid collisions between wavelengths, but also take into account the transmittable distance. In other words, the APN 50 including such nodes 11, . . . , 25 and nodes 41, 42, 43 corresponds to a transparent optical network.

[0025] Next, the hardware configuration of the optical network controller 100 will be described with reference to FIG.

[0026] The optical network controller 100 includes a CPU (Central Processing Unit) 100A as a processor, and a RAM (Random Access Memory) 100B and a ROM (Read Only Memory) 100C as memories. The optical network controller 100 also includes a network I / F (Interface) 100D and an HDD (Hard Disk Drive) 100E. Instead of the HDD (Hard Disk Drive) 100E, an SSD (Solid State Drive) may be used as a storage device.

[0027] The optical network controller 100 may include at least one of an input I / F 100F, an output I / F 100G, an input / output I / F 100H, and a drive device 100I, as necessary. The CPU 100A to the drive device 100I are connected to each other by an internal bus 100J. In other words, the optical network controller 100 can be realized by a computer.

[0028] An input device 710 is connected to the input I / F 100F. Examples of the input device 710 include a keyboard, a mouse, and a touch panel. A display device 720 is connected to the output I / F 100G. Examples of the display device 720 include an LCD display. A semiconductor memory 730 is connected to the input / output I / F 100H. Examples of the semiconductor memory 730 include a USB (Universal Serial Bus) memory and a flash memory. The input / output I / F 100H reads the optical network management program stored in the semiconductor memory 730. The input I / F 100F and the input / output I / F 100H each include, for example, a USB port. The output I / F 100G includes, for example, a display port.

[0029] A portable recording medium 740 is inserted into the drive device 100I. The portable recording medium 740 may be a removable disk such as a CD (Compact Disc)-ROM or a DVD (Digital Versatile Disc). The drive device 100I reads an optical network management program recorded on the portable recording medium 740. The network I / F 100D includes, for example, a LAN port and a communication circuit. The communication circuit includes either or both of a wired communication circuit and a wireless communication circuit. The network I / F 100D is connected to NMSs 19 and 29 and nodes 14 and 41 via a communication network 100K. The communication network 100K includes either or both of the Internet and a LAN (Local Area Network).

[0030] An optical network management program stored in at least one of the ROM 100C, the HDD 100E, and the semiconductor memory 730 is temporarily stored in the RAM 100B by the CPU 100A. An optical network management program recorded on the portable recording medium 740 is temporarily stored in the RAM 100B by the CPU 100A. By executing the stored optical network management program, the CPU 100A realizes various functions described below and executes an optical network management method including various processes described below. The optical network management program may be one that corresponds to the flowchart described below.

[0031] The functional configuration of the optical network controller 100 will be described with reference to Figures 3 to 6. Note that Figure 3 shows the main functions of the optical network controller 100.

[0032] 3, the optical network controller 100 includes a storage unit 110, a processing unit 120, an input / output unit 130, and a communication unit 140. The storage unit 110 can be realized by either or both of the RAM 100B and the HDD 100E described above. The processing unit 120 can be realized by the CPU 100A described above. The input / output unit 130 can be realized by the input / output I / F 100H described above. The communication unit 140 can be realized by the network I / F 100D described above.

[0033] The memory unit 110, processing unit 120, input / output unit 130, and communication unit 140 are connected to one another. The memory unit 110 includes a channel management DB (Data Base) 111. The processing unit 120 includes an allocation unit 121, a first management unit 122, a second management unit 123, a third management unit 124, and a design unit 125. The allocation unit 121 is an example of an acquisition means and a reservation means. The second management unit 123 is an example of a determination means.

[0034] The channel management DB 111 is a database for managing the inventory of wavelengths used in optical communication services. As shown in Fig. 4, the channel management DB 111 manages the inventory of wavelengths using a channel management table T1. For example, the channel management table T1 manages 96 wavelengths λ1,...,λ96 belonging to the C band (Conventional Band) by associating them with optical channels "Ch01" to "Ch96" as identification numbers.

[0035] The C band is, for example, a wavelength band of 1530 nm (nanometers) to 1565 nm. For example, wavelength λ1, which is the shortest wavelength belonging to the C band, is associated with optical channel "Ch01." Wavelength λ96, which is the longest wavelength belonging to the C band, is associated with optical channel "Ch96." Instead of 96 wavelengths, for example, 48 wavelengths may be used as the number of wavelengths. In this case, since the number of optical channels corresponds to the number of wavelengths, optical channels "Ch01" to "Ch48" are used.

[0036] The L band (Long Band) may be added to the C band. The L band is, for example, a long wavelength band of 1565 nm to 1625 nm. In this case, 96 wavelengths belonging to the L band are added, making a total of 192 wavelengths available for providing optical communication services. The S band (Short Band) may also be added to the C band and the L band. The S band is, for example, a wavelength band of 1460 nm to 1530 nm. In this case, 96 wavelengths belonging to the S band are added, making a total of 288 wavelengths available for providing optical communication services.

[0037] Here, when a request is made to open an inter-domain service, which is an optical communication service between PDNs 10 and 20 across PCN 40, optical channel "Ch01" corresponding to the first row in channel management table T1 is selected and used first. Thereafter, when a request is made to open another inter-domain service between PDNs 10 and 20, if optical channel "Ch01" is in use, optical channel "Ch02" corresponding to the row immediately following the first row is selected and used. In this way, in inter-domain services, optical channels are used in ascending order.

[0038] On the other hand, when a request is made to open an intra-domain service, which is an optical communication service within PDN 20 that does not cross PCN 40, the optical channel "Ch96" corresponding to the last row of channel management table T1 is first selected and used. Thereafter, when a request is made to open another intra-domain service within PDN 20, if optical channel "Ch96" is in use, the optical channel "Ch95" corresponding to the row immediately before the last row is selected and used. In this way, for intra-domain services, optical channels are selected and used in descending order. Note that the optical communication service within PDN 10 is similar to the optical communication service within PDN 20, and therefore a detailed description thereof will be omitted.

[0039] Returning to FIG. 3, the allocation unit 121 obtains a predetermined number from a setting file 70 for initial setting. The setting file 70 is an example of setting information. The setting file 70 may be stored in the semiconductor memory 730, or may be stored in advance in the storage unit 110. The setting file 70 includes the number N of optical channels used in the inter-domain service (hereinafter referred to as the number of inter-domain channels). The number N of inter-domain channels is an example of a first number of channels. The setting file 70 also includes the number I of optical channels used in the intra-domain service (hereinafter referred to as the number of intra-domain channels). The number I of intra-domain channels is an example of a second number of channels.

[0040] The allocation unit 121 acquires the number of inter-domain channels N and the number of intra-domain channels I as predetermined numbers. In this embodiment, the number of inter-domain channels N is 8. Also, in this embodiment, the number of intra-domain channels I is 16. The number of inter-domain channels N and the number of intra-domain channels I may be changed as appropriate.

[0041] The number of intra-domain channels I may be determined as a multiple of the number of inter-domain channels N. For example, the number of intra-domain channels I may be determined as an integer multiple, such as two or three times the number of inter-domain channels N. As will be described in detail later, when a request is made to add a PDN different from either PDN 10 or 20 to APN 50, allocation unit 121 obtains the number of inter-domain channels N and the number of intra-domain channels I.

[0042] Furthermore, the allocation unit 121 allocates reservations for optical channel groups in a number corresponding to the number N of inter-domain channels used between each of the PDNs 10 and 20 and another PDN. Specifically, the allocation unit 121 allocates reservations for optical channel groups in a number that is a multiple of the number N of inter-domain channels.

[0043] For example, when allocating reservations for a single optical channel group, as shown in the upper part of Figure 5, the allocation unit 121 allocates reservations for an optical channel group of eight channels, from optical channel "Ch01" to optical channel "Ch08." Note that at the stage when such an optical channel group is reserved, an optical path has not been set. Therefore, no optical channel has been allocated to the optical path. At the stage when an optical channel group is reserved, "unavailable" is registered as the availability of the optical channel. Also, at this stage, an identification number "1020" that can identify this as an inter-domain service provided between PDNs 10 and 20 is registered as the network ID.

[0044] The first management unit 122 manages the optical channels used for intra-domain services among the optical channels managed in the channel management table T1. Specifically, the first management unit 122 manages the number of optical channels used for intra-domain services. For example, if the number of optical channels used in either PDN 10 or 20 exceeds the number of intra-domain channels I at the specific timing when adding another PDN as described above, the first management unit 122 displays a message suggesting the addition of a node.

[0045] The second management unit 123 manages optical channels used in inter-domain services among the optical channels managed in the channel management table T1. Specifically, the second management unit 123 manages the number of optical channels used in the inter-domain services. Furthermore, before the allocation unit 121 allocates reservations for the above-mentioned optical channel group to the channel management DB 111, the second management unit 123 determines whether there is free space in the channel management DB 111 (specifically, the channel management table T1). When the second management unit 123 determines whether there is free space in the channel management DB 111, it notifies the allocation unit 121 of the determination result.

[0046] The third management unit 124 manages reusable optical channels. Even if optical channels to be used in an inter-domain service are reserved, there are cases where a portion of the reserved optical channels is already in use for the inter-domain service when a request to open the inter-domain service is made. In such cases, the third management unit 124 manages the remaining portion of the reserved optical channels as reusable optical channels and selects a reusable optical channel as necessary.

[0047] When a request is made to open an optical communication service, the design unit 125 designs an optical path and sets the designed optical path in the APN 50 to accommodate it. The design unit 125 may be requested to open an inter-domain service in which a start node and an end node are specified along with a network ID. In this case, when the second management unit 123 selects one of the optical channels to which a reservation is assigned, the design unit 125 designs an optical path from the start node to the end node based on transmission degradation factors such as PMD and a predetermined algorithm. The predetermined algorithm may be, for example, integer linear programming.

[0048] The design unit 125 may design one optical path or multiple optical paths. If the design unit 125 designs multiple optical paths, it can output information to the display device 720 requesting the selection of one of the multiple optical paths. If the design unit 125 designs one optical path, it assigns a selected optical channel to the designed optical path and sets and accommodates the optical path in the APN 50. For example, as shown in FIG. 6, the design unit 125 sets and accommodates an optical path P1 to which the optical channel "Ch01" is assigned between PDNs 10 and 20 across the PCN 40. This allows mobile terminals 81 and 82, such as smartphones, to use inter-domain services via the optical path P1.

[0049] When optical path P1 is accommodated, the second management unit 123 changes the setting of the optical path to which optical channel "Ch01" is assigned from "unset" to "set," as shown in the lower part of Fig. 5. The second management unit 123 maintains the setting of the optical path to which optical channel "Ch01" is not assigned as "unset." In addition, the second management unit 123 collects nodes in the entire network to which optical channel "Ch01" has not been assigned, determines available inter-domain services, and then designates optical channel "Ch01" as a reusable optical channel.

[0050] In this way, when an optical path is set, the reservations of the remaining nodes not assigned to that optical path are released, the use of that optical channel is permitted, and that optical channel is designated as a reusable optical channel. Meanwhile, the second management unit 123 maintains the availability of the optical paths to which optical channels "Ch02" to "Ch08" are assigned as unavailable.

[0051] On the other hand, when a request is made to open an intra-domain service in which a start node and an end node are specified along with a network ID, the design unit 125 selects one of the unused optical channels. After selecting the optical channel, the design unit 125 designs an optical path from the start node to the end node, just as in the case of an inter-domain service. For example, as shown in Figure 6, the design unit 125 sets up and accommodates optical path P2 of optical channel "Ch96" in PDN 20.

[0052] This allows mobile terminals 83 and 84 such as PCs (Personal Computers) to use intra-domain services via the optical path P2. When the optical path P2 is accommodated, the first management unit 122 registers "set" in the optical path settings and "available" in the usable / unusable field, as shown in the lower part of Fig. 5 .

[0053] Here, there may be a shortage of free space in the channel management table T1 before the allocation unit 121 reserves the optical channel group. As will be described in detail later, in this case, the second management unit 123 releases some of the predetermined optical channels that have already been reserved by deleting them from the channel management table T1, and allocates the reservation of the optical channel group to the free space in the channel management table T1 after releasing some of the predetermined optical channels.

[0054] In this way, reservations for optical channel groups are dynamically secured depending on when the channel management table T1 runs out of free space. Therefore, even if the APN 50 is scaled out, there is no need to redesign the optical paths for the APN 50. This reduces the design load in the optical path accommodation design.

[0055] Next, a first operation of the optical network controller 100 will be described with reference to FIGS.

[0056] First, as shown in Fig. 7, the allocation unit 121 acquires the number of reserved channels (step S1). For example, when PDNs 10 and 20 are already included in APN 50 (see Fig. 1), and addition of another PDN different from PDNs 10 and 20 is requested from input device 710, the allocation unit 121 acquires the number of reserved channels. In this case, the allocation unit 121 accesses the configuration file 70 and acquires the number of inter-domain channels N (e.g., N=8) included in the configuration file 70 as the number of reserved channels.

[0057] When the allocation unit 121 acquires the number of reserved channels, the second management unit 123 then determines whether there are any vacant channels in the channel management table T1 (step S2). More specifically, the second management unit 123 accesses the channel management DB 111 and determines whether there are any vacant channels in the channel management table T1 that are a multiple of the number of reserved channels. That is, the second management unit 123 determines whether there are any unused channels in the channel management table T1 that are a multiple of the number of reserved channels.

[0058] For example, when an APN 50 already includes PDNs 10 and 20, as shown in FIG. 9 , a request may be made to add another PDN 30, which is different from PDNs 10 and 20. PDN 30 includes multiple nodes 31, 32, and 33, such as nodes 11 and 21. The telecommunications carrier that manages PDN 30 is different from the telecommunications carriers that manage PDNs 10 and 20. When the addition of such a PDN 30 is requested, reservation allocation of optical channels equal to the number of reserved channels is required between PDNs 10 and 30 and between PDNs 20 and 30. That is, reservation allocation of eight optical channels is required between PDNs 10 and 30, and reservation allocation of eight optical channels is required between PDNs 20 and 30. As a result, when the addition of PDN 30 is requested, reservation allocation of 16 optical channels, which is twice the number of reserved channels, is required. Here, channel management table T1 is partially occupied by the eight optical channels between the existing PDNs 10 and 20. Therefore, when the PDN 30 is added, it is occupied by 24 (=8+16) optical channels.

[0059] Similarly, although not shown, when APN 50 already includes three PDNs, PDNs 10, 20, and 30, and a request is made to add a fourth PDN, the reservation allocation of 24 optical channels is requested. As a result, channel management table T1 is occupied by 48 optical channels (=24+24). Then, when a request is made to add a fifth PDN, the reservation allocation of 32 optical channels is requested. As a result, channel management table T1 is occupied by 80 optical channels (=48+32).

[0060] In this way, each time a PDN is added, the free space (unused channels) in the channel management table T1 decreases. Consider a case where the channel management table T1 is occupied by 17 optical channels from the end of the channel management table T1 based on intra-domain services. In this case, when a request is made to add a fifth PDN, the 96 optical channels will exceed the reserved area of ​​the channel management table T1. This is because 80 optical channels already occupy the channel management table T1. Therefore, adding a fifth PDN to APN 50 requires a process different from the above-described addition process. In this way, the second management unit 123 determines whether there is free space in the channel management table T1 each time a request is made to add a PDN.

[0061] If no optical channels based on intra-domain services are occupied and the addition of a fifth PDN is permitted, the channel management table T1 will be occupied by 80 optical channels, as described above. In this state, if the addition of a sixth PDN is requested, the reservation and allocation of 40 optical channels is required. Even in this case, adding a sixth PDN to APN 50 requires a process different from the addition process described above.

[0062] In the processing of step S2, if there is an empty space in the channel management table T1 (step S2: YES), the allocation unit 121 allocates reservations for the optical channel groups (step S3) and ends the processing. For example, the allocation unit 121 allocates reservations for the optical channel groups equal to the number of reserved channels between PDNs 10 and 30 and between PDNs 20 and 30, respectively. As a result, as shown in Fig. 8, reservations for eight optical channel groups from optical channel "Ch09" to optical channel "Ch16" are allocated for the inter-domain service between PDNs 10 and 30. Also, reservations for eight optical channel groups from optical channel "Ch17" to optical channel "Ch24" are allocated for the inter-domain service between PDNs 20 and 30.

[0063] 9, similar to the inter-domain service between PDNs 10 and 20, an inter-domain service between PDNs 20 and 30 may be requested to be opened, and optical path P3 may be accommodated. In this case, the design unit 125 sets up and accommodates optical path P3, to which optical channel "Ch17" is assigned, between PDNs 20 and 30 across PCN 40. This allows mobile terminals 83 and 84 to use the inter-domain service via optical path P3.

[0064] 8, the second management unit 123 changes the optical path setting of, for example, optical channel "Ch17" from "unset" to "set." The second management unit 123 designates such optical channel "Ch17" as a reusable optical channel, and the third management unit 124 manages the designated reusable optical channels.

[0065] On the other hand, if there is no vacancy in the channel management table T1 in the processing of step S2 (step S2: NO), the second management unit 123 determines whether there are many unused optical channel groups to which reservations have already been assigned (step S4). For example, as shown in Fig. 8, seven optical channel groups, from optical channel "Ch02" to optical channel "Ch08" used in the inter-domain service between PDNs 10 and 20, are registered as "unavailable" as their usability. In other words, these seven optical channel groups are unused. Similarly, seven optical channel groups, from optical channel "Ch18" to optical channel "Ch24" used in the inter-domain service between PDNs 20 and 30, are registered as "unavailable" as their usability. In other words, these seven optical channel groups are also unused.

[0066] Here, if a threshold number of optical channels, for example, five, or more are unused, the second management unit 123 determines that many are unused (step S4: YES). In this case, the second management unit 123 releases some of the unused optical channels by deleting them (step S5). For example, as shown in FIG. 10, the second management unit 123 releases four optical channels from the seven optical channel group from optical channel "Ch02" to optical channel "Ch08" by deleting them. In this case, the second management unit 123 releases the latter half of the seven optical channel group, that is, the four optical channels from optical channel "Ch05" to optical channel "Ch08," by deleting them. Similarly, the second management unit 123 releases the latter half of the seven optical channel group from optical channel "Ch74" to optical channel "Ch80," that is, the four optical channels from optical channel "Ch77" to optical channel "Ch80." The same applies to the remaining inter-domains omitted in FIG. 10. The number of deleted lines may be two or three.

[0067] In this way, the second management unit 123 releases, by deletion, a portion of the unused optical channel group between each domain, such as between PDNs 10 and 20 or between PDNs 20 and 30. Furthermore, if an optical path to which optical channel "Ch09" is assigned is accommodated in APN 50, the second management unit 123 similarly releases, by deletion, a portion of the unused optical channel group between PDNs 10 and 30. As a result, when a request is made to add a sixth PDN, the second management unit 123 secures 40 free optical channels. As a result, even when a request is made to add a sixth PDN, the allocation unit 121 can allocate reservations for the optical channel group to the free spaces secured by the second management unit 123. After the second management unit 123 releases a portion of the unused optical channel group in this way, the allocation unit 121 executes the process of step S3 and ends the process.

[0068] In the process of step S4, if the number of unused optical channels is less than the threshold number, the second management unit 123 determines that there are few unused channels (step S4: NO). In this case, the second management unit 123 displays a first message (step S6) and ends the process. For example, the second management unit 123 displays a message proposing the addition of a new APN different from APN 50 as the first message on the display device 720 and ends the process. This allows the operator to consider adding a new APN.

[0069] Next, a second operation of the optical network controller 100 will be described with reference to FIGS.

[0070] 11, the design unit 125 determines whether or not the service is an inter-domain service (step S11). For example, when the opening of an optical communication service is requested from the input device 710, the design unit 125 determines whether or not an inter-PDN service has been requested as the optical communication service, based on the network ID. The operator in charge of operating the APN 50 can specify the network ID and input it into the input device 710.

[0071] If it is an inter-domain service (step S11: YES), the second management unit 123 determines whether there is any unsetup (step S12). For example, the second management unit 123 accesses the channel management table T1. When the second management unit 123 accesses the channel management table T1, it checks the setting status of the optical path setting associated with the network ID and determines whether there is any unsetup among the optical path settings.

[0072] If there is an unconfigured optical channel (step S12: YES), the second management unit 123 selects one of the optical channels (step S13). More specifically, the second management unit 123 selects the optical channel with the smallest channel number from among the optical channels for which no optical path is configured. For example, if the configuration status of eight optical channels from optical channel "Ch01" to optical channel "Ch08" is unconfigured (see the upper part of FIG. 5), the second management unit 123 selects the first optical channel, "Ch01." For example, if the configuration status of seven optical channels from optical channel "Ch02" to optical channel "Ch08" is unconfigured (see the lower part of FIG. 5), the second management unit 123 selects the next first optical channel, "Ch02."

[0073] When the second management unit 123 selects any one of the optical channels, the design unit 125 designs an optical path for the inter-domain service (step S14). That is, the design unit 125 designs an optical path to which the selected optical channel is assigned and accommodates the designed optical path. As a result, for example, optical path P1 is accommodated between PDNs 10 and 20 (see FIG. 6). When the design unit 125 designs the optical path, the second management unit 123 designates the selected optical channel as a reusable optical channel (step S15). After the second management unit 123 designates the selected optical channel as a reusable optical channel, the third management unit 124 manages the reusable optical channel designated by the second management unit 123 in the channel management table T1, and the process ends.

[0074] Here, in the process of step S12, if there is no unconfigured optical channel (step S12: NO), the third management unit 124 determines whether or not there is a reusable optical channel (step S16), as shown in Fig. 12. More specifically, the third management unit 124 accesses the channel management table T1 and determines whether or not there is a reusable optical channel corresponding to the network ID.

[0075] If there are reusable optical channels (step S16: YES), the third management unit 124 selects any one of the reusable optical channels (step S17). More specifically, the third management unit 124 selects the reusable optical channel with the smallest optical channel number. As a result, as shown in Fig. 11, the design unit 125 designs an optical path to which the reusable optical channels are assigned by the processing of step S14. Thereafter, the third management unit 124 again designates the remaining reusable optical channels as reusable optical channels by the processing of step S15, and ends the processing.

[0076] 12, if there is no reusable optical channel in the processing of step S16 (step S16: NO), the second management unit 123 determines whether there is an unconfigured optical channel (step S18). In this case, the second management unit 123 accesses the channel management table T1 and identifies another network ID that is different from the network ID specified when the inter-domain service is opened. After identifying the other network ID, the second management unit 123 checks the setting status of the optical path setting associated with the identified other network ID and determines whether there is an unconfigured optical path setting.

[0077] If there is an unconfigured optical channel (step S18: YES), the second management unit 123 moves the optical channel (step S19). More specifically, when the second management unit 123 identifies multiple other network IDs, it calculates the optical path setup rate for each of the identified other network IDs. After calculating the setup rate, the second management unit 123 identifies the other network ID corresponding to the lowest setup rate. When the second management unit 123 identifies the other network ID, it selects one of the optical channels associated with the identified other network ID as the one to be moved.

[0078] When the second management unit 123 selects one of the optical channels as a movement target, it moves the selected optical channel to the row corresponding to the network ID specified in the opening of the inter-domain service. For example, when the second management unit 123 identifies the network ID "4050," it moves the optical channel "Ch76" associated with the network ID "4050" to the row corresponding to the network ID "1020."

[0079] When an optical channel is moved, the second management unit 123 selects the moved optical channel (step S20). As a result, as shown in Fig. 11, the design unit 125 designs an optical path to which the moved optical channel is assigned by the processing of step S14. Thereafter, the second management unit 123 designates the remaining optical channels as reusable optical channels by the processing of step S15, and ends the processing. Note that, in the processing of step S18, if there are no unconfigured optical channels (step S18: NO), the second management unit 123 displays a first message (step S21), and ends the processing as shown in Fig. 11.

[0080] Furthermore, in the process of step S11, if the service is not an inter-domain service (step S11: NO), the first management unit 122 determines whether there is a vacant channel (step S22). For example, if the service is not an inter-domain service, the first management unit 122 determines that the service is an intra-domain service, accesses the channel management table T1, and determines whether there is a vacant optical channel corresponding to the number of intra-domain channels I.

[0081] If there is a vacant channel (step S22: YES), the design unit 125 designs an optical path for the intra-domain service (step S23) and terminates the process. More specifically, the first management unit 122 checks the channel management table T1 and selects one optical channel from the end. Once the first management unit 122 selects an optical channel, the design unit 125 designs an optical path to which the selected optical channel is assigned and accommodates the designed optical path.

[0082] As a result, for example, optical path P2 is accommodated in PDN 20 (see FIG. 6). On the other hand, if there is no vacancy (step S22: NO), the first management unit 122 displays a second message (step S24) and terminates the process. For example, the first management unit 122 displays a message proposing the addition of a node (specifically, a path) as the second message on the display device 720 and terminates the process.

[0083] As described above, the optical network controller 100 according to this embodiment determines whether there is a vacancy in the channel management table T1, for example, every time a request is made to add a new PDN (e.g., PDN 30, etc.). Specifically, the optical network controller 100 determines whether there is a vacancy in the channel management table T1 that allows the reservation of an optical channel group with the number of inter-domain channels N for each existing PDN (e.g., PDN 10, 20, etc.) to which a reservation has already been assigned.

[0084] If there is no such free space, the optical network controller 100 releases the latter half of the optical channel for the existing PDN reserved in the channel management table T1 by deleting it. Then, the optical network controller 100 allocates the reservation of the optical channel corresponding to the addition of the new PDN to the released latter half. This allows the addition of the new PDN.

[0085] That is, according to this embodiment, on-demand operation is possible in which optical paths are set up only when necessary. In particular, when the PDNs 10, 20 and PCN 40 are mesh-type, the APN 50 accommodates optical paths that are more complex than those in the ring type, but even in such cases, there is no need to pre-design the optical paths. Furthermore, even when a scale-out occurs, such as adding a node or a new PDN, there is no need to redesign the optical paths in the APN 50. In this way, according to this embodiment, the design load in optical path accommodation design is reduced.

[0086] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and variations are possible within the scope of the gist of the present invention as described in the claims.

[0087] For example, the configuration file 70 may include a frequency band (e.g., 400 GHz) equivalent to the number of inter-domain channels N, instead of the number of inter-domain channels N. The configuration file 70 may also include a wavelength band equivalent to the number of inter-domain channels N. Even if the configuration file 70 includes such a frequency band or wavelength band, the design load in the optical path accommodation design is reduced, as in the above-described embodiment.

[0088] In addition, the following supplementary notes are provided in relation to the above description. (Supplementary Note 1) An optical network management device that manages an optical network in which a plurality of unit optical networks are optically connected, comprising: an acquisition means for, when a request is made to add another unit optical network different from any of the plurality of unit optical networks to the optical network, acquiring the first channel number from setting information including a first channel number of first optical channels used between the plurality of unit optical networks and a second channel number of second optical channels used within each unit optical network belonging to the optical network; a determination means for determining whether or not there is space in a database that manages the plurality of optical channels used in the optical network before a number of first optical channel groups corresponding to the first channel number used between each of the plurality of unit optical networks and the another unit optical network are reserved; and a reservation means for, when there is no space in the database, releasing from the database a portion of the predetermined optical channels that have already been reserved, and allocating the reservation of the first optical channel group to the space in the database after the portion of the predetermined optical channels has been released. (Appendix 2) The optical network management device described in Appendix 1, characterized in that the determination means releases the latter half of the specified optical channel from the database, and the reservation means allocates the reservation for the first optical channel group to the vacant space in the database after releasing part of the specified optical channel. (Appendix 3) The optical network management device described in Appendix 1 or 2, characterized in that the reservation means assigns to the database a reservation for the first optical channel group that is a multiple of the first number of channels used between each of the plurality of unit optical networks and the other unit optical network. (Appendix 4) The optical network management device described in Appendix 1 or 2, characterized in that when the judgment means determines that an optical path has been set up for a part of the first optical channel group, it releases the reservation allocation for the remainder of the first optical channel group and allows the remainder to be reused. (Appendix 5) The optical network management device described in Appendix 1 or 2, characterized in that the judgment means displays a message proposing the addition of a new unit optical network that is different from both the plurality of unit optical networks and the other unit optical network when there is no vacancy in the database and the number of unused channels in the first optical channel group is less than a threshold number. (Appendix 6) An optical network management device as described in Appendix 1 or 2, characterized in that at least one of the plurality of unit optical networks includes a plurality of nodes connected in a mesh configuration, and each of the plurality of nodes outputs the wavelength of the input optical signal without converting it. (Supplementary Note 7) The optical network management device according to Supplementary Note 1 or 2, wherein a single wavelength is assigned to each of a plurality of optical paths accommodated in the plurality of unit optical networks for each optical communication service. (Supplementary Note 8) An optical network management method for managing an optical network in which a plurality of unit optical networks are optically connected, when a request is made to add another unit optical network different from any of the plurality of unit optical networks to the optical network, the method comprising: obtaining the first channel number from setting information including a first channel number of first optical channels used between the plurality of unit optical networks and a second channel number of second optical channels used within each unit optical network belonging to the optical network; determining whether or not there is free space in a database managing the plurality of optical channels used in the optical network before a first optical channel group corresponding in number to the first channel number used between each of the plurality of unit optical networks and the another unit optical network is reserved; and if there is no free space in the database, releasing from the database some of the predetermined optical channels that have already been reserved, and allocating the reservation of the first optical channel group to the free space in the database after releasing some of the predetermined optical channels. [Explanation of symbols]

[0089] 10, 20, 30 PDN 40 PCN 50 APN 100 Optical Network Controller 121 Allocation Section 122 1st Management Department 123 2nd Management Department 124 Third Management Department 125 Design Department P1, P2, P3 optical path

Claims

1. An optical network management device that manages an optical network in which a plurality of unit optical networks are optically connected, comprising: an acquisition means for acquiring, when a request is made to add another unit optical network different from any of the plurality of unit optical networks to the optical network, the first channel number from setting information including a first channel number of first optical channels used among the plurality of unit optical networks and a second channel number of second optical channels used within each unit optical network belonging to the optical network; a determination means for determining whether or not there is free space in a database managing a plurality of optical channels used in the optical network before a number of first optical channel groups corresponding to the number of first channels used between each of the plurality of unit optical networks and the other unit optical network are reserved; a reservation means for releasing a portion of the predetermined optical channels that have already been reserved from the database when there is no vacancy in the database, and allocating the reservation of the first optical channel group to the vacancy in the database after the portion of the predetermined optical channels has been released; An optical network management device having:

2. the determining means releases the latter half of the predetermined optical channel from the database; the reservation unit allocates the reservation of the first optical channel group to the vacant space in the database after releasing a part of the predetermined optical channels; 2. The optical network management device according to claim 1.

3. the reservation means allocates to the database a reservation for the first optical channel group, the number of which is a multiple of the first number of channels used between each of the plurality of unit optical networks and the other unit optical network; 3. The optical network management device according to claim 1 or 2.

4. when the determination means determines that an optical path has been set for a part of the first optical channel group, the determination means releases the reservation allocation for the remaining part of the first optical channel group and permits reuse of the remaining part.

3. The optical network management device according to claim 1 or 2.

5. when there is no free space in the database and the number of unused channels in the first optical channel group is less than a threshold number, the determining means displays a message proposing the addition of a new unit optical network different from any of the plurality of unit optical networks and the other unit optical network.

3. The optical network management device according to claim 1 or 2.

6. At least one of the plurality of unit optical networks includes a plurality of nodes connected in a mesh configuration; each of the plurality of nodes outputs an input optical signal without converting the wavelength of the input optical signal; 3. The optical network management device according to claim 1 or 2.

7. An optical network management method for managing an optical network in which a plurality of unit optical networks are optically connected, comprising: When a request is made to add another unit optical network different from any of the plurality of unit optical networks to the optical network, the first channel number is obtained from setting information including a first channel number of first optical channels used among the plurality of unit optical networks and a second channel number of second optical channels used within each unit optical network belonging to the optical network; determining whether or not there is free space in a database managing a plurality of optical channels used in the optical network before reserving a number of first optical channel groups corresponding to the number of first channels used between each of the plurality of unit optical networks and the other unit optical network; if there is no vacancy in the database, releasing a part of the predetermined optical channels that have already been reserved from the database, and allocating the reservation of the first optical channel group to the vacancy in the database after releasing the part of the predetermined optical channels; Optical network management methods.

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