Optical path design device, optical path system, and optical path design method

Abstract

An optical path design device (10) comprising: an input unit (12A) that receives a setting request for an optical path between nodes which is set straddling a plurality of provider networks; an optical path connection unit (11A) that requests, from each provider network that the optical path between the nodes passes through, candidate provider-internal optical paths to become the route of the optical path between the nodes, and determines provider-internal optical paths to use from the collected provider-internal optical path candidate information on the basis of the total of costs per each provider-internal optical path from the starting point to the ending point of the optical path between the nodes; and an output unit (12B) that notifies each provider network of the determined provider-internal optical paths.

Description

Optical path design device, optical path system, and optical path design method

[0001] The present invention relates to an optical path design device, an optical path system, and an optical path design method.

[0002] The realization of an all-optical network that allows optical path connections at both ends (E2E: End to End) is becoming a reality, and studies are being conducted to provide optical paths in E2E. The optical path route may be confined within the same telecommunications carrier (hereinafter referred to as "carrier"), but it may also span multiple carriers. A typical optical path design method targeted at a single carrier enables optimal design by utilizing network information within the carrier's own network, but it is difficult to apply it to design in a multi-domain environment such as inter-carrier connections.

[0003] Here, there are cases where network information cannot be shared between operators due to the network information sharing policies of each operator across the optical path route. Therefore, Non-Patent Document 1 considers an optical path system in which network information is not shared between operators and an upper optical network controller (hereinafter referred to as "upper controller") has network information of lower operators.

[0004] Deepak Batham et al., “A traffic scheduling strategy based on cost function for differentiated class of service in multi-domain optical networks”, Optical Fiber Technology, Volume 60, 2020

[0005] As for the network information sharing policies of operators, there are also highly confidential policies in which detailed network information (topology, wavelength usage status, etc.) cannot be shared between operators and operators do not provide detailed network information to upper controllers.

[0006] FIG. 12 is a configuration diagram of an optical path system 100z including carrier networks operated by three carriers. The optical NW 40z has three carrier networks. Each carrier manages its own carrier network (hereinafter referred to as "own network") using a lower-level controller 30z. The upper-level controller 20z receives an E2E optical path setting request from a user and deploys the optical path setting request within each carrier (to a location within the carrier) to each lower-level controller 30z. The upper-level controller 20z then sets up an E2E optical path by connecting the optical paths within the carrier set by each lower-level controller 30z.

[0007] Here, optimal optical path design will be considered for the following policies as well: - The upper controller 20z cannot obtain detailed information about each operator's network. - The lower controller 30z can obtain detailed information and optical path setting requests within its own network. - The lower controller 30z cannot obtain detailed information and optical path setting requests within other operators' networks (hereinafter referred to as "other networks").

[0008] It is not enough for E2E optical paths to simply be connectable; it is desirable to optimally design them from the perspective of at least one of improving the quality of services provided to users and reducing costs for operators. For example, shortening the transmission distance of the optical path (reducing detours and traveling the shortest distance possible) reduces communication delays and improves service quality. Furthermore, reducing the number of wavelength conversions in the connection devices between operators reduces costs for operators. Therefore, the lower-level controller 30z can access network information within its own network, allowing it to optimize optical paths within its own network. On the other hand, the upper-level controller 20z does not receive detailed information about each operator's network from the lower-level controller 30z, making it difficult to optimize E2E optical paths connecting operator networks.

[0009] Therefore, the main object of the present invention is to optimize optical path design across multiple operators even when detailed information about the network within the operator is kept secret.

[0010] In order to solve the above problems, the optical path design device of the present invention comprises the following means: an input unit that receives a setting request for a ground-to-ground optical path that is set across a plurality of carrier networks, an optical path connection unit that requests candidates for intra-carrier optical paths that serve as routes for the ground-to-ground optical path from each carrier network through which the ground-to-ground optical path passes, and determines the intra-carrier optical path to be adopted from the collected information on the candidates for the intra-carrier optical path based on the total cost of each intra-carrier optical path from the start point to the end point of the ground-to-ground optical path, and an output unit that notifies each carrier network of the determined intra-carrier optical path.

[0011] According to the present invention, it is possible to optimize optical path design across multiple operators even when detailed information about the network within the operator is kept secret.

[0012] 1 is a configuration diagram of an optical path system according to the present embodiment. FIG. 2 is a configuration diagram of an optical path design device according to the present embodiment. FIG. 3 is a flowchart showing the processing of the optical path design device according to the present embodiment. FIG. 4 is a configuration diagram of an optical path information DB according to the present embodiment. FIG. 5 is an explanatory diagram of the cost of an intra-carrier optical path according to the present embodiment. FIG. 6 is a hardware configuration diagram of each device in the optical path system according to the present embodiment. FIG. 7 is a configuration diagram showing an example of an optical NW according to the present embodiment. FIG. 8 is a management table of intra-carrier optical paths designed by a carrier A management device according to the present embodiment. FIG. 9 is a management table of intra-carrier optical paths designed by a carrier B management device according to the present embodiment. FIG. 10 is a management table of intra-carrier optical paths designed by a carrier C management device according to the present embodiment. FIG. 11 is a configuration diagram of an optical path system including carrier networks respectively operated by three carriers.

[0013] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0014] FIG. 1 is a configuration diagram of an optical path system 100. The optical path system 100 is configured by connecting each carrier network (carrier A-NW41, carrier B-NW42, carrier C-NW43) of the optical network 40 and management side devices (optical path design device 10, optical network management device 20, carrier-specific management device) of the optical network 40 via a network. The optical network 40 serves as a backbone network such as an IP communication network, realizing communication using optical signals. Note that the carrier B-NW42 is an inter-carrier network connecting the carrier A-NW41 and the carrier C-NW43, but it can also take the form of an interconnection point between carriers consisting of a single site (device). The carrier A-B device 34 is a boundary communication device connecting the carrier A-NW41 and the carrier B-NW42. The carrier B-C device 35 is a boundary communication device connecting the carrier B-NW42 and the carrier C-NW43.

[0015] The provider-specific management devices include a provider A management device 31 that manages a provider A-NW 41, a provider B management device 32 that manages a provider B-NW 42, and a provider C management device 33 that manages a provider C-NW 43. The optical NW management device 20 integrates the respective provider-specific management devices by having a higher-level controller function that manages and controls the lower-level provider-specific management devices. Meanwhile, the provider-specific management devices have a lower-level controller function that manages and controls their own networks and a function that designs optical paths (intra-provider optical paths) within their own networks. The optical NW management device 20 receives an optical path setting request for an E2E optical path from a user 9 and expands it into an intra-provider optical path setting request for each provider-specific management device. Note that an E2E optical path is a ground-to-ground optical path that is set across multiple provider networks. The optical NW management device 20 then connects (integrates) the intra-provider optical paths set by each provider-specific management device to set an E2E optical path.

[0016] Here, it is assumed that the optical path system 100 has the following highly confidential policy set as a network information sharing policy by each operator: The optical NW management device 20 cannot obtain detailed information (topology, wavelength usage status, etc.) of the optical NW 40 (operator-specific network). A operator-specific management device (for example, the operator A management device 31) can obtain network information within its own network (for example, the operator A-NW 41) and intra-operator optical path setting requests within its own network. A operator-specific management device (for example, the operator A management device 31) cannot obtain detailed information of networks within other networks (for example, the operator B-NW 42, the operator C-NW 43), intra-operator optical path setting requests within other networks, or E2E optical path setting requests.

[0017] For example, suppose that an end point within the provider A-NW 41 and an end point within the provider C-NW 43 are specified as end points of the E2E optical path in the optical path setting request. At this time, the optical NW management device 20 configures the E2E optical path by connecting the first intra-provider optical path, the second intra-provider optical path, and the third intra-provider optical path. - A first intra-provider optical path within the provider A-NW 41 from the end point within the provider A-NW 41 to the inter-provider A-B device 34. - A second intra-provider optical path within the provider B-NW 42 from the inter-provider A-B device 34 to the inter-provider B-C device 35. - A third intra-provider optical path within the provider C-NW 43 from the inter-provider B-C device 35 to an end point within the provider C-NW 43.

[0018] The optical path design device 10 performs the following steps to design an E2E optical path in response to an optical path setting request. (Step 1) The optical path design device 10 receives from the optical NW management device 20 an optical path setting request (such as information on source / destination nodes) for an E2E optical path transmitted from the user 9 to the optical NW management device 20, and instructs each provider-specific management device via the optical NW management device 20 to design an intra-provider optical path. (Step 2) When designing intra-provider optical path candidates in response to the instruction in (Step 1), the provider-specific management device also calculates the cost for each intra-provider optical path candidate. The provider-specific management device then returns the intra-provider optical path candidates and their costs to the optical NW management device 20 as masked (partially concealed) intra-provider optical path information. (Step 3) The optical path design device 10 receives the result of (Step 2) from the optical NW management device 20 and designs an optimal E2E optical path based on the cost for each intra-provider optical path candidate. The optical NW management device 20 and the optical path design device 10 may be the same device, or may be separate devices connected by an API or the like.

[0019] In (Step 2), the per-carrier management device designs intra-carrier optical paths with limited information on other carriers and E2E optical paths, as follows: Design processing that takes into account transmission quality when the amount of quality degradation is unknown. Design processing that accommodates the inflow of external wavelengths.

[0020] In (Step 3), the optical path design device 10 integrates and adjusts the intra-carrier optical paths designed by each carrier management device, and designs an E2E path that takes transmission quality into consideration, as follows: Wavelength adjustment processing between networks, including the use of wavelength conversion functions. Management processing of the transmission quality of optical paths at E2E.

[0021] FIG. 2 is a configuration diagram of the optical path design device 10. The optical path design device 10 includes a processing unit 11 (optical path connection unit 11A), an input / output unit 12 (input unit 12A, output unit 12B), and a storage unit 13 (carrier information DB 13A, optical path information DB 13B). The optical path design device 10 may be configured as a single device, or may be configured with its functions distributed across multiple devices. The optical path connection unit 11A designs an E2E optical path that connects carrier networks in response to a specified optical path setting request, based on the information in the storage unit 13. To this end, the optical path connection unit 11A requests each carrier network through which the ground-to-ground optical path passes for intra-carrier optical path candidates that serve as the route of the ground-to-ground optical path, and determines the intra-carrier optical path to be adopted based on the collected information on the intra-carrier optical path candidates and the total cost of each intra-carrier optical path from the start point to the end point of the ground-to-ground optical path.

[0022] The input unit 12A accepts input of an optical path setting request that has arrived at the optical NW management device 20. The output unit 12B outputs the execution result of the optical path connection unit 11A. The carrier information DB 13A stores information indicating the connection relationships between each carrier's intra-network and node information (a list of node identification information) contained in each carrier's intra-network, as information indicating an overview of the optical path system 100. However, due to the information confidentiality policy of each carrier, the carrier information DB 13A does not store detailed information (topology, wavelength usage status, etc.) of the networks managed by each carrier-specific management device. The optical path information DB 13B stores the optical path setting request accepted by the input unit 12A.

[0023] 3 is a flowchart showing the processing of the optical path design device 10. The input unit 12A stores an optical path setting request (S11) input from the user 9 to the optical NW management device 20 in the optical path information DB 13B. To this end, the user 9 creates an optical path setting request specifying the endpoints (both end points) of the optical path.

[0024] 4 is a diagram showing the configuration of the optical path information DB 13B. The optical path information DB 13B stores an optical path ID, an optical path name, a start node, an end node, a bandwidth, a wavelength used, and an assigned route in association with each optical path setting request.

[0025] 3 , the optical path connection unit 11A refers to the carrier information DB 13A and the optical path information DB 13B and requests each carrier-specific management device to design intra-carrier optical paths that constitute the E2E optical path (S12). Each requested carrier-specific management device designs K (e.g., K=3) connection candidates for intra-carrier optical paths. The optical path connection unit 11A collects information (cost Clocal and connection wavelengths) of the K connection candidates for intra-carrier optical paths from each carrier-specific management device via the optical NW management device 20 (S13).

[0026] 5 is an explanatory diagram of the cost Clocal of an intra-carrier optical path calculated in S13. An example is given using the following parameters. - Assuming an intra-carrier network = an intra-carrier optical path route connected in the order of nodes A, B, C, and D, the route length Rlocal = 50, which is the total distance of the route. - The number of wavelengths prepared in the intra-carrier network = 80. - The number of wavelengths used by transit links in the route = 20 wavelengths for link AB, 50 wavelengths for link BC, and 10 wavelengths for link CD. - The maximum number of wavelengths used by transit links in the route λmax = 50 wavelengths for link BC.

[0027] Each provider-specific management device calculates the intra-provider optical path cost Clocal using the following (Equation 1): Clocal = Rlocal × (1 + α × λmax ÷ λcap) (Equation 1) Here, the second coefficient = coefficient α is set to 1, for example, and the provider-specific management device accepts input of the second coefficient. As a result, when an extremely large value is input as the second coefficient, the optical path system 100 can indirectly reflect the administrator's policy in the path design, for example, by increasing fault tolerance by not essentially having multiple paths share the same link.

[0028] Furthermore, "λmax ÷ λcap" is the wavelength utilization rate of the link through which the path passes. For the intra-provider optical path in Figure 5, Clocal = 50 × (1 + 1 × 50 ÷ 80) = 81.25. Furthermore, the higher the value of the coefficient α, the more the design reflects the wavelength utilization rate of the link in the intra-provider optical path cost, enabling load balancing of the route. In this way, when calculating candidates for intra-provider optical paths requested by the optical path connection unit 11A, the per-provider management device calculates the cost of each intra-provider optical path based on the route length of the intra-provider optical path and the wavelength utilization rate of the link through which the intra-provider optical path passes.

[0029] 3, the optical path connection unit 11A derives an E2E optical path with the smallest total cost from the start point to the end point based on the costs of each intra-carrier optical path of the connection candidates collected in S13 (S14). The output unit 12B notifies each individual carrier management device of the intra-carrier optical path to be used in the E2E optical path derived in S14 (S15). Each individual carrier management device prepares an E2E optical path by creating the notified intra-carrier optical path.

[0030] FIG. 6 is a hardware configuration diagram of each device in the optical path system 100. Each device in the optical path system 100 is configured as a computer 900 having a CPU 901, RAM 902, ROM 903, HDD 904, communication I / F 905, input / output I / F 906, and media I / F 907. The communication I / F 905 is connected to an external communication device 915. The input / output I / F 906 is connected to an input / output device 916. The media I / F 907 reads and writes data from a recording medium 917. Furthermore, the CPU 901 controls each unit by executing a program (optical path design program) loaded into the RAM 902. This program (also called an application, or an app for short) can be distributed via a communication line or recorded on a recording medium 917 such as a USB memory stick.

[0031] The processing in the flowchart of FIG. 3 will be explained further below with reference to the specific examples shown in FIGS. 7 to 11. FIG. 7 is a configuration diagram showing an example of an optical network 40. In the optical network 40, an operator A-NW 41 accommodating nodes A1 to A3 and an operator C-NW 43 accommodating nodes C1 to C3 are connected via an operator B-NW 42 accommodating nodes B1 to B4. Nodes AB1 and AB2 exist as an inter-operator A-B device 34, and nodes BC1 and BC2 exist as an inter-operator B-C device 35. The distance between the nodes (e.g., 25) is added to the link connecting the nodes (e.g., between nodes A1 and A2). The nodes are optical cross connect (OXC) devices, and the inter-operator A-B device 34 and the inter-operator B-C device 35 further have wavelength conversion functions.

[0032] In the following explanation, it is assumed that the optical path connection unit 11A requests each of the provider-specific management devices to design K=3 intra-provider optical paths that constitute the E2E optical path, based on the optical path setting request between nodes A1 and C3 received by the input unit 12A in S11 (S12). The provider A management device 31 designs three intra-provider optical paths from node A1 to the inter-provider A-B device 34 within the provider A-NW 41 (see FIG. 8 for details). The provider B management device 32 designs three intra-provider optical paths from the inter-provider A-B device 34 to the inter-provider B-C device 35 within the provider B-NW 42 (see FIG. 9 for details). The provider C management device 33 designs three intra-provider optical paths from the inter-provider B-C device 35 to node C3 within the provider C-NW 43 (see FIG. 10 for details).

[0033] FIG. 8 shows a management table of intra-carrier optical paths designed by the provider A management device 31. The management tables 111 and 112 are obtained by dividing one table into two using the "shortest route order" as a key. Therefore, for each shortest route order of the intra-carrier optical paths, the management tables 111 and 112 associate the endpoint information (A endpoint, Z endpoint) of the intra-carrier optical path, the route information of the intra-carrier optical path (passing link "1," passing link "2," passing link "3," route length R, maximum number of wavelengths used (maximum value λmax), number of wavelengths λcap, and cost C), and the connection wavelength used by the intra-carrier optical path. Passing link "1" is the first link from the starting point. To keep information about its own network confidential, the provider A management device 31 notifies the optical NW management device 20 of three sets of correspondence information (shortest route order, endpoint information, cost C, and connection wavelength) from the management tables 111 and 112. The other information in the management tables 111 and 112 is masked and not notified to the optical NW management device 20 .

[0034] 9 shows a management table of intra-carrier optical paths designed by the provider B management device 32. As in FIG. 8, the management tables 121 and 122 in FIG. 9 are each formed by dividing one table into two using the "shortest route order" as a key. The management tables 121 and 122 have the same items as the management tables 111 and 112 in FIG. 8, but a via link "4" in the route information of the intra-carrier optical path is added. In order to keep information about its own network confidential, the provider B management device 32 notifies the optical NW management device 20 of three sets of correspondence information of "shortest route order, endpoint information, cost Clocal, and connection wavelength" in the management tables 121 and 122.

[0035] Fig. 10 shows a management table of intra-carrier optical paths designed by the carrier C management device 33. As in Fig. 8, the management tables 131 and 132 in Fig. 10 are each formed by dividing one table into two using the "shortest route order" as a key. In order to keep information about its own network confidential, the carrier C management device 33 notifies the optical NW management device 20 of three sets of correspondence information of "shortest route order, endpoint information, cost C local, and connection wavelength" from the management tables 131 and 132.

[0036] FIG. 11 shows a management table of E2E optical paths designed by the optical path design device 10. The optical path connection unit 11A collects, via the optical NW management device 20, the correspondence information of "shortest route order, endpoint information, cost Clocal, and connection wavelength" notified to the optical NW management device 20 from the management tables of FIGS. 8 to 10 (S13). Then, the optical path connection unit 11A creates E2E optical path candidates by combining intra-carrier optical paths that have the same endpoint and can be connected to each other, based on the endpoint information of each intra-carrier optical path. The Z endpoint "AB1" in the first row of the management table 111 and the A endpoint "AB1" in the first row of the management table 121 are the same node and can be connected to each other. The Z endpoint "AB1" in the first row of the management table 111 and the A endpoint "AB2" in the second row of the management table 121 are different nodes and cannot be connected to each other.

[0037] Furthermore, the optical path connection unit 11A derives an E2E optical path cost Ce for the created E2E optical path. Therefore, the management table 141 in FIG. 11 associates, as a calculation result of the optical path connection unit 11A, the shortest route order (intra-carrier route order A, intra-carrier route order B, intra-carrier route order C) of the intra-carrier optical paths combined as the E2E optical path with the total Ctotal of the costs Clocal of the intra-carrier optical paths in that combination. For example, the first row of the management table 141 in FIG. 11 lists a candidate E2E optical path that combines "intra-carrier route order = 1 (first row of FIG. 8), intra-carrier route order = 1 (first row of FIG. 9), intra-carrier route order = 1 (first row of FIG. 10)." The total cost of this E2E optical path is Ctotal = 49.6 + 217.7 + 60.7 = 328.0. Then, the optical path connection unit 11A sets the E2E optical path cost Ce=the total cost Ctotal, and determines the intra-carrier optical path to be adopted so that the E2E optical path cost Ce is minimum.

[0038] Furthermore, the management table 141 in FIG. 11 associates the connection wavelength of each intra-carrier optical path with the number of adjustments Nchange, which indicates the number of times the wavelength adjustment function is used, and the E2E optical path cost Ce. The wavelength adjustment function adjusts (converts) the connection wavelength. The carrier-specific management device appropriately uses (controls) the wavelength adjustment function described below to deal with cases where the designated wavelength of the optical path to be accommodated is full across all links in the route. (Function 1) The wavelength conversion function is implemented in the optical network 40 to be accommodated and changes the designated wavelength of the optical path to be accommodated. (Function 2) The wavelength defragmentation function is implemented in the carrier-specific management device that manages the optical network 40 to be accommodated and changes the accommodated wavelength of an optical path already accommodated. Note that the carrier-specific management device uses the wavelength defragmentation function (Function 2) when the service of existing paths is not affected (e.g., during maintenance of the network or the optical path to be defragmented). In other cases, it uses the wavelength conversion function (Function 1).

[0039] Because the connection wavelength "15 → 23 → 23" in the first row of the management table 141 indicates that one wavelength conversion (15 → ​​23) is required at the inter-carrier A-B device 34, but zero wavelength conversions (23 → 23) are required at the inter-carrier B-C device 35 because the wavelength is the same. In other words, the number of adjustments Nchange = 1 + 0 = 1. The optical path connection unit 11A may calculate the E2E optical path cost Ce using the following formula (2) instead of "E2E optical path cost Ce = total cost Ctotal." Ce = Ctotal + β × Nchange (Formula 2). The first coefficient (coefficient β) is set to, for example, "100," and the input unit 12A accepts the input of the first coefficient. This allows the optical path design device 10 to indirectly reflect the administrator's policy in the path design, for example, by effectively disabling the wavelength tuning function if an extremely large value is input as the first coefficient. In this way, the optical path connection unit 11A reads the connection wavelength for each intra-carrier optical path from the information on the candidate intra-carrier optical paths notified by each carrier-specific management device, and then determines the intra-carrier optical path to be adopted so that the total cost obtained by adding the conversion cost according to the number of conversions of the connection wavelength to the total cost for each intra-carrier optical path from the start point to the end point of the ground-to-ground optical path is minimized.

[0040] The optical path connection unit 11A derives the E2E optical path with the smallest E2E optical path cost Ce (the E2E optical path in the first row in FIG. 11 ) from the management table 141 (S14). As a result, the route and connection wavelength of the intra-carrier optical path of each carrier are determined as details of the E2E optical path to be designed. The output unit 12B notifies each carrier-specific management device of the intra-carrier optical path to be used in the E2E optical path derived by the optical path connection unit 11A as follows (S15). The output unit 12B notifies the carrier A management device 31 to create a first intra-carrier optical path that uses a connection wavelength of 15 as a route with shortest route order = 1 and converts it to a connection wavelength of 23 at node AB1. The output unit 12B notifies the carrier B management device 32 to create a second intra-carrier optical path that uses a connection wavelength of 23 as a route with shortest route order = 1. The provider C management device 33 is notified to create a third intra-provider optical path using a connection wavelength of 23 as a route with the shortest route order of 1. Furthermore, the output unit 12B notifies each provider-specific management device to connect the first intra-provider optical path → the second intra-provider optical path → the third intra-provider optical path as one E2E optical path.

[0041] [Effect] The optical path design device 10 of the present invention is characterized by having an input unit 12A that receives a setting request for a ground-to-ground optical path that is set across multiple carrier networks; an optical path connection unit 11A that requests candidate intra-carrier optical paths that will be the route of the ground-to-ground optical path from each carrier network through which the ground-to-ground optical path passes, and determines the intra-carrier optical path to be adopted from the collected information on the candidate intra-carrier optical paths based on the total cost of each intra-carrier optical path from the start point to the end point of the ground-to-ground optical path; and an output unit 12B that notifies each carrier network of the determined intra-carrier optical path.

[0042] This allows the optical path design device 10 to optimize optical path design across operators without using specific information (routed links, route length) within the operator's network, even when detailed information about the network within the operator is kept confidential.

[0043] The present invention is characterized in that the information on candidate intra-provider optical paths includes the connection wavelength for each intra-provider optical path, and the optical path connection unit 11A determines the intra-provider optical path to be adopted so that the total cost, which is the sum of the costs for each intra-provider optical path from the start point to the end point of the ground-to-ground optical path plus the conversion cost according to the number of conversions of the connection wavelength, is minimized.

[0044] This allows the optical path design apparatus 10 to reflect the usage status of the wavelength tuning function and to highly accurately optimize optical path designs spanning multiple operators.

[0045] The present invention is characterized in that the input unit 12A receives the input of the first coefficient, and the optical path connection unit 11A multiplies the conversion cost by the first coefficient and then adds the result to the total cost.

[0046] This allows the optical path design device 10 to indirectly reflect the administrator's policy in the path design, such as by effectively not allowing the wavelength adjustment function to be used if an extremely large value is input as the first coefficient.

[0047] The present invention is an optical path system 100 having an optical path design device 10 and a carrier-specific management device provided in each carrier network, characterized in that when the carrier-specific management device calculates candidates for intra-carrier optical paths requested by the optical path connection unit 11A, it calculates the cost for each intra-carrier optical path based on the route length of the intra-carrier optical path and the wavelength utilization rate of the link through which the intra-carrier optical path passes.

[0048] As a result, the optical path system 100 can achieve load balancing among optical paths by preferentially selecting intra-operator optical paths, avoiding as much as possible the selection of unstable links with extremely high wavelength utilization rates (links that are close to being blocked).

[0049] The present invention is characterized in that the per-provider management device multiplies the wavelength utilization rate of the link through which the intra-provider optical path passes by a second coefficient, and then calculates the cost for each intra-provider optical path.

[0050] This allows the optical path system 100 to indirectly reflect the administrator's policy in the path design, such as by effectively preventing multiple paths from sharing the same link, thereby increasing fault tolerance, when an extremely large value is input as the second coefficient.

[0051] 10 Optical path design device 11A Optical path connection unit 12A Input unit 12B Output unit 13 Storage unit 31 Provider A management device (per-provider management device) 32 Provider B management device (per-provider management device) 33 Provider C management device (per-provider management device) 40 Optical NW 41 Provider A-NW (each provider network) 42 Provider B-NW (each provider network) 43 Provider C-NW (each provider network) 100 Optical path system

Claims

1. An optical path design device comprising: an input unit that receives a request to set an end-to-end optical path that is set across multiple carrier networks; an optical path connection unit that requests candidate intra-carrier optical paths that will be the route of the end-to-end optical path from each carrier network through which the end-to-end optical path passes, and determines the intra-carrier optical path to be adopted based on the collected information on the candidate intra-carrier optical paths and the total cost of each intra-carrier optical path from the start point to the end point of the end-to-end optical path; and an output unit that notifies each carrier network of the determined intra-carrier optical path.

2. The optical path design device of claim 1, characterized in that the information on the candidates for the intra-carrier optical paths includes a connection wavelength for each of the intra-carrier optical paths, and the optical path connection unit determines the intra-carrier optical path to be adopted so as to minimize the total cost obtained by adding the sum of the costs for each of the intra-carrier optical paths from the start point to the end point of the ground-to-ground optical path plus a conversion cost according to the number of conversions of the connection wavelength.

3. The optical path design device according to claim 2, wherein the input unit accepts input of a first coefficient, and the optical path connection unit multiplies the conversion cost by the first coefficient and then adds the result to the total cost.

4. An optical path system comprising an optical path design device according to any one of claims 1 to 3 and a per-carrier management device provided in each carrier network, wherein the per-carrier management device, when calculating candidates for the intra-carrier optical paths requested by the optical path connection unit, calculates the cost for each intra-carrier optical path based on the route length of the intra-carrier optical path and the wavelength utilization rate of the link through which the intra-carrier optical path passes.

5. The optical path system according to claim 4, wherein the per-provider management device multiplies the wavelength utilization rate of the link through which the intra-provider optical path passes by a second coefficient, and then calculates the cost for each intra-provider optical path.

6. An optical path design method, comprising: an optical path design device having an input unit, an optical path connection unit, and an output unit; wherein the input unit receives a request to set a ground-to-ground optical path that is set across multiple carrier networks; the optical path connection unit requests candidates for intra-carrier optical paths that will be the route of the ground-to-ground optical path from each carrier network through which the ground-to-ground optical path passes; and determines the intra-carrier optical path to be adopted from the collected information on the candidates for the intra-carrier optical path based on the total cost of each intra-carrier optical path from the start point to the end point of the ground-to-ground optical path; and the output unit notifies each carrier network of the determined intra-carrier optical path.

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