Optical path design device, optical path design method and program

Abstract

Provided is an optical path designing device comprising: a transmission quality calculating unit that estimates the transmission quality of a plurality of candidate pathways in an optical transmission network; and a pathway selection unit that selects, from the plurality of candidate pathways, a candidate pathway which reaches the transmission quality.

Description

[Technical Field]

[0001] The present invention relates to an optical path design device, an optical path design method, and a program. [Background technology]

[0002] In optical transmission networks, communication data is handled using light, and the communication demands that exist within an optical transmission network are called lightpaths. In order to improve the accommodation efficiency of lightpaths, wavelength allocation methods and route calculation methods for lightpaths are being studied. In this case, in order to accurately transmit information converted into light at the start node to the end node, it is necessary to calculate the route taking into account the transmission quality of the lightpath.

[0003] A conventional technique has been proposed that takes transmission quality into consideration when calculating a route (Non-Patent Document 1). In the conventional technique, a combination of a route and a wavelength with a small optical signal to noise ratio (OSNR) is selected for a given modulation method. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] R. Cardillo, V. Curri, M. Mellia, "Considering transmission impairments in configuring wavelength routed optical networks,'" in Proc. OFC / NFOEC 2006, Anaheim, CA, USA, March 2006. Summary of the Invention [Problem to be solved by the invention]

[0005] Conventional technologies have a problem in that, because the modulation method is fixed, if the given modulation method cannot satisfy the transmission quality required for the optical path, the optical path cannot be established. In such cases, it may be possible to establish the optical path by passing through a regenerator (a device that eliminates attenuation and degradation of optical signals by OEO conversion) along the optical path route, but the use of expensive regenerators increases the cost of the optical path, which becomes a problem. Furthermore, in practical optical transmission networks, there are few nodes equipped with regenerators, so it is possible that the transmission distance will be longer due to passing through a regenerator.

[0006] The disclosed technology aims to realize an optical path design that allows the modulation method to be changed depending on the transmission quality. [Means for solving the problem]

[0007] The disclosed technology includes a transmission quality calculation unit that estimates the transmission quality of a plurality of candidate routes in an optical transmission network, and a transmission quality calculation unit that calculates a transmission quality from the plurality of candidate routes. , required and a route selection unit for selecting a candidate route that satisfies the transmission quality. wherein the route selection unit selects a candidate route having a modulation mode that can be transmitted for a route length of each candidate route included in the plurality of candidate routes based on information indicating modulation modes that can be used by devices that configure the optical transmission network, determines whether the selected candidate route satisfies an optical path delay requirement and a GSNR requirement corresponding to the modulation mode, and deletes a route that does not satisfy the requirements from the candidate routes. is. [Effects of the Invention]

[0008] It is possible to realize an optical path design that allows the modulation method to be changed depending on the transmission quality. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 illustrates an example of a functional configuration of an optical path design apparatus. [Figure 2] 10 is a flowchart illustrating an example of the flow of an optical path design process. [Figure 3] FIG. 1 illustrates an example of an optical transmission network. [Figure 4] FIG. 10 is a diagram illustrating an example of a topology information DB. [Figure 5] FIG. 10 is a diagram illustrating an example of a wavelength information DB. [Figure 6] FIG. 10 is a diagram illustrating an example of an optical path information DB. [Figure 7] FIG. 10 is a diagram illustrating an example of a device information DB. [Figure 8] FIG. 10 is a diagram illustrating an example of a candidate route information DB. [Figure 9] FIG. 2 is a diagram illustrating an example of an optical path information DB according to the embodiment. [Figure 10] FIG. 2 is a first diagram illustrating an example of a candidate route information DB according to the embodiment. [Figure 11] FIG. 10 is a diagram illustrating an example of a device information DB according to the embodiment. [Figure 12] FIG. 10 is a second diagram illustrating an example of the candidate route information DB according to the embodiment. [Figure 13] FIG. 10 is a third diagram illustrating an example of the candidate route information DB according to the embodiment. [Figure 14] FIG. 10 is a fourth diagram illustrating an example of a candidate route information DB according to the embodiment. [Figure 15] FIG. 10 is a fifth diagram illustrating an example of a candidate route information DB according to the embodiment. [Figure 16] FIG. 10 is a diagram illustrating an example of a wavelength information DB according to the embodiment. [Figure 17] FIG. 6 is a sixth diagram illustrating an example of a candidate route information DB according to the embodiment. [Figure 18] FIG. 2 illustrates an example of the hardware configuration of a computer. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention (the present embodiment) will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0011] (Outline of this embodiment) The optical path design device of this embodiment is a device that designs optical paths in an optical transmission network, and performs route search in optical path design by taking into account the transmission quality of the route and the modulation mode used on the route when searching for a route.

[0012] The numbers and names of reference documents related to the reference techniques of this embodiment are listed at the end of this embodiment. In the following description, the numbers of related reference documents are indicated as "[1]" etc.

[0013] (Example of functional configuration of optical path design device) 1 is a diagram illustrating an example of a functional configuration of an optical path design apparatus 1. The optical path design apparatus 1 includes a route determination unit 10, a storage unit 20, and an input / output unit 30.

[0014] The route determination unit 10 includes a route calculation unit 11, a transmission quality calculation unit 12, a route selection unit 13, and a route evaluation unit 14.

[0015] The route calculation unit 11 derives a route based on information stored in a topology information DB 21 and a wavelength information DB 22, which will be described later. The transmission quality calculation unit 12 calculates the transmission quality of the route based on information stored in the topology information DB 21, which will be described later.

[0016] The route selection unit 13 determines candidate routes based on the transmission distance of the route and the transmission quality values ​​stored in the transmission quality DB. The route evaluation unit 14 evaluates the candidate routes determined by the route selection unit 13 and either determines one route or ranks the routes in order of priority.

[0017] The storage unit 20 includes a topology information DB 21, a wavelength information DB 22, an optical path information DB 23, a device information DB 24, and a candidate route information DB 25.

[0018] The topology information DB 21 is a database that stores topology information, which indicates the connection relationships between nodes and links in an optical transmission network, the distances between nodes, and so on.

[0019] The wavelength information DB 22 is a database that stores wavelength information, which indicates the usage status of wavelengths in each link of the optical transmission network.

[0020] The optical path information DB 23 is a database that stores optical path information, which is information indicating requirements for optical paths to be set in the optical transmission network.

[0021] The device information DB 24 is a database that stores device information, which indicates the modulation method, loss, etc. of devices in the optical transmission network.

[0022] The candidate route information DB 25 is a database that stores candidate route information, which is information indicating candidate routes calculated by the route calculation unit 11, transmission quality calculated by the transmission quality calculation unit 12 for the candidate routes, and the like.

[0023] The input / output unit 30 includes an input unit 31 and an output unit 32. The input unit 31 inputs information such as topology information, wavelength information, optical path information, and device information. The output unit 32 outputs route information indicating the route determined by the route determination unit 10.

[0024] (Operation of optical path design device) Next, the operation of the optical path design apparatus 1 will be described with reference to the drawings. Here, the overall flow of processing will be mainly described, and the details of each processing step will be described later.

[0025] 2 is a flowchart showing an example of the flow of an optical path design process. As a preparatory step, the input unit 31 inputs topology information, wavelength information, optical path information, and device information via a user operation or transmission from an external device (step S101).

[0026] Next, the route calculation unit 11 derives N pieces of candidate route information and stores them in the candidate route information DB 25 (step S102).The route calculation unit 11 derives the route length of each of the N pieces of candidate route information (step S103).

[0027] Next, the transmission quality calculation unit 12 selects one candidate route from the candidate route information, and determines a modulation mode that can be transmitted based on the route length of the selected candidate route (step S104).

[0028] The route selection unit 13 determines whether or not there is a modulation mode that can transmit the selected candidate route (step S105). If the route selection unit 13 determines that there is no modulation mode that can transmit the selected candidate route (step S105: NO), it deletes the selected candidate route information from the candidate route information DB (step S106).

[0029] Furthermore, if the route selector 13 determines that there is a modulation mode that can transmit data through the selected candidate route (step S105: YES), it skips the process of step S106.

[0030] The route selection unit 13 determines whether the selected route satisfies the delay requirement of the optical path and the transmission quality corresponding to the modulation mode (step S107). If the route selection unit 13 determines that the selected route does not satisfy the delay requirement of the optical path and the transmission quality corresponding to the modulation mode (step S107: NO), it deletes the selected candidate route information from the candidate route information DB (step S108).

[0031] Furthermore, if the route selector 13 determines that the selected route satisfies the delay requirement of the optical path and the transmission quality corresponding to the modulation mode (step S107: YES), it skips the process of step S108.

[0032] The route selection unit 13 determines whether or not N candidate routes have been selected (step S109). If the route selection unit 13 determines that N candidate routes have not been selected (step S109: NO), the process returns to step S104 and the route selection unit 13 selects the next candidate route.

[0033] When the route selection unit 13 determines that N candidate routes have been selected (step S109: YES), the route evaluation unit 14 compares the bit rate of the selected modulation mode with the required bit rate of the optical path for each candidate route, and derives the number of carriers to be used (step S110).

[0034] Then, the route evaluation unit 14 derives an assigned wavelength for each candidate route (step S111). The route evaluation unit 14 compares the maximum wavelength numbers among one or more wavelength numbers assigned to each candidate route, and determines the candidate route with the smallest wavelength number as the route (step S112).

[0035] The method of determining the route in the process of step S112 is a method for equalizing the wavelength utilization rate of each route in the optical transmission network, and other methods may be used.

[0036] The output unit 32 outputs route information indicating the determined route (step S113). The route information output in this manner is information indicating a route in which the transmission quality of the optical path is taken into consideration.

[0037] Fig. 3 is a diagram illustrating an example of an optical transmission network. The optical transmission network illustrated in Fig. 3 includes a plurality of OXC (Optical Cross Connect) nodes and links between the respective OXC nodes. Each link may include one or a plurality of ILAs (In Line Amplifiers). The optical path design device 1 designs optical paths in the optical transmission network illustrated in Fig. 3, for example.

[0038] Fig. 4 is a diagram showing an example of a topology information DB. The topology information shown in Fig. 4 is information indicating the positional relationships in the optical transmission network shown in Fig. 3. Specifically, the topology information includes numbers for identifying the OXC nodes at both ends of each link, the distance of each link, numbers for identifying each link, etc.

[0039] FIG. 5 is a diagram showing an example of a wavelength information DB. The wavelength information shown in FIG. 5 is information indicating the number of the wavelength used by each link. In FIG. 5, for each wavelength number, either a value (1) indicating that the wavelength is in use or a value (0) indicating that the wavelength is not in use is set. Each wavelength number is associated with a specific wavelength in advance. For example, a smaller wavelength number may be associated with a smaller wavelength, but this is not limiting.

[0040] Fig. 6 is a diagram showing an example of an optical path information DB. The optical path information shown in Fig. 6 is information indicating the requirements of an optical path to be set in an optical transmission network. The optical path information sets bit rate, delay requirements, and the like as examples of the requirements for each combination of the start point and end point of the optical path to be designed. Items in the optical path information DB may be added when an optical path setting request arrives.

[0041] Fig. 7 is a diagram showing an example of the device information DB. The device information shown in Fig. 7 includes the type of device (OXC or ILA) that realizes the function of each OXC node, the cost incurred by passing through the device, a number for identifying a modulation mode that can be set in the transponder of each OXC, the bit rate, modulation method, symbol rate, GSNR threshold value, etc. in each modulation mode.

[0042] The numbers indicating the available modulation modes, the bit rate, modulation method, symbol rate, GSNR threshold value, etc. in each modulation mode are set when the type of device is OXC.

[0043] Fig. 8 is a diagram showing an example of the candidate route information DB. The candidate route information shown in Fig. 8 is information indicating candidate routes derived by the route calculation unit 11. The candidate route information includes items such as wavelength used, transmission distance, cost, modulation mode used, GSNR, and via links.

[0044] The value of the item "Wavelength Used" indicates the wavelength used in the candidate route. The value of the item "Transmission Distance" indicates the transmission distance of the candidate route. The value of the item "Cost" is the total cost of the devices that the candidate route passes through.

[0045] The value of the item "used modulation mode" indicates the modulation mode used in the candidate route, and is, for example, a value in the format of (node ​​name-modulation mode number). The value of the item "GSNR" indicates the quality of the transmission path derived by the transmission quality calculation unit 12. The value of the item "via link" is one or more links used in the route.

[0046] (Specific Examples) A specific example of this embodiment will be described below, and the details of each of the above-mentioned processes will also be further explained.

[0047] Fig. 9 is a diagram showing an example of an optical path information DB according to the embodiment. In the process of step S101 in Fig. 2, the input unit 31 inputs, for example, the optical path information shown in Fig. 9. Here, the input unit 31 may input topology information, wavelength information, device information, etc. in advance.

[0048] The route calculation unit 11 refers to the combination of the start node and the end node of the optical path and the required bit rate from the optical path information. Then, the route calculation unit 11 derives multiple candidate routes that reach the end node from the start node, and stores candidate route information indicating the derived candidate routes in the candidate route information DB 25.

[0049] In this embodiment, the route calculation unit 11 searches for an optical path route that transmits at 400 Gbps from N1 to N8.

[0050] 10 is a first diagram showing an example of a candidate route information DB according to an embodiment. In the process of step S102 in FIG. 2, the route calculation unit 11 derives candidate routes for an optical path transmitting from the start node N1 to the end node N8. The route calculation unit 11 may derive K shortest routes using a K-shortest path [1] as a method for deriving candidate routes. Note that the method for deriving candidate routes is not limited to this. In this embodiment, the route calculation unit 11 derives five shortest routes using a K-shortest path algorithm [1] with K=5, and stores candidate route information such as that shown in FIG. 10 in the candidate route information DB 25.

[0051] In step S104, the route selector 13 determines a modulation mode that can transmit the candidate route based on the route length for each candidate route derived in step S103 of Fig. 2. Fig. 11 is a diagram illustrating an example of a device information DB according to the embodiment. Fig. 12 is a second diagram illustrating an example of a candidate route information DB according to the embodiment.

[0052] When the route selection unit 13 determines the modulation mode for each candidate route with reference to the device information DB shown in FIG. 11, it updates the candidate route information stored in the candidate route information DB as shown in FIG.

[0053] Then, the route selection unit 13 deletes the candidate route information for which there is no modulation mode that can be transmitted by the process of step S106 from the candidate route information DB.

[0054] Here, the transmission quality calculation unit 12 estimates the transmission time of each candidate route. For example, the transmission quality calculation unit 12 calculates the transmission time of a route by dividing the transmission distance by the propagation speed of the signal in the optical fiber. In this embodiment, the transmission quality calculation unit 12 derives the transmission time by setting the propagation speed of the signal in the optical fiber to 200,000 (km / s).

[0055] Then, in the process of step S107 in Fig. 2, the route selection unit 13 determines whether the candidate route satisfies the delay requirement required for the optical path. In this embodiment, the route selection unit 13 determines that the delay requirement of the optical path is 7 ms from the optical path information shown in Fig. 9. Therefore, the route selection unit 13 compares the transmission time and the delay requirement from the transmission distance of each candidate route shown in Fig. 12, and deletes candidate route information indicating a route that does not satisfy the delay requirement (the fifth entry in the candidate route information DB shown in Fig. 12) from the candidate route information DB.

[0056] 13 is a third diagram illustrating an example of the candidate route information DB according to the embodiment. Fig. 13 illustrates the candidate route information DB in the present embodiment in a state in which routes that do not satisfy the delay requirement have been deleted.

[0057] Furthermore, in the process of step S107 in FIG. 2, the transmission quality calculation unit 12 estimates the transmission quality of each candidate route stored in the candidate route information DB, and updates the candidate route information stored in the candidate route information DB.

[0058] Specifically, the transmission quality calculation unit 12 may employ any of the following estimation methods.

[0059] In the first estimation method, the transmission quality calculation unit 12 may estimate the transmission quality of the entire candidate route by measuring the transmission quality of each device, optical fiber, etc. in advance and using the results stored in a database.

[0060] In the second estimation method, the transmission quality calculation unit 12 may estimate the transmission quality of the candidate route using an OSS library (such as GNPy[2]) that can estimate the transmission quality.

[0061] In the third estimation method, the transmission quality calculation unit 12 may actually set an optical path using a candidate route in the optical transmission network and measure the transmission quality.

[0062] The method for estimating the transmission quality is not limited to the above-mentioned methods, and other methods may be used.

[0063] 14 is a fourth diagram illustrating an example of the candidate route information DB according to the embodiment. FIG. 14 illustrates the candidate route information DB in a state in which the value of the item “GSNR” has been updated as a value indicating the estimated transmission quality.

[0064] The route selector 13 determines whether the candidate route satisfies the transmission quality for the modulation of the optical path. Specifically, the route evaluator 14 determines whether the transmission quality is satisfied by comparing the GSNR threshold for the modulation mode of each candidate route with the transmission quality of each candidate route.

[0065] Then, the route selection unit 13 deletes the candidate route information indicating the route that does not satisfy the quality from the candidate route information DB in the processing of step S108 in Fig. 2. In this embodiment, the route selection unit 13 deletes the candidate route information indicating the route that does not satisfy the transmission quality (the fourth entry in the candidate route information DB shown in Fig. 14) from the candidate route information DB.

[0066] 15 is a fifth diagram illustrating an example of the candidate route information DB according to the embodiment. Fig. 15 illustrates the candidate route information DB in the present embodiment in a state in which routes that do not satisfy the transmission quality are deleted.

[0067] The route evaluation unit 14 derives the number of carriers to be used in step S110 of Fig. 2. Specifically, to derive the number of carriers to be used, the route evaluation unit 14 compares the bit rate of the selected modulation mode with the required bit rate of the optical path, thereby deriving the number of carriers to be used.

[0068] For example, in the candidate route information of the first entry in the candidate route information DB shown in Fig. 15, modulation mode 1 of 400 Gbps is selected, so the number of carriers used is 1. In contrast, in the candidate route information of the second and third entries, modulation mode 2 of 200 Gbps is selected, so the number of carriers used is 2.

[0069] Next, the route evaluation unit 14 derives the assigned wavelength in step S111 of Fig. 2. Specifically, the route evaluation unit 14 acquires information indicating wavelengths that are already in use from the wavelength information DB.

[0070] Fig. 16 is a diagram showing an example of a wavelength information DB according to the embodiment. Fig. 16 shows information indicating wavelengths that are already in use in this embodiment. The route evaluation unit 14 may derive the wavelength to be assigned to each candidate route according to first-fit wavelength assignment. First-fit wavelength assignment is a method of assigning the shortest wavelength from among available wavelengths.

[0071] Fig. 17 is a sixth diagram illustrating an example of the candidate route information DB according to the embodiment. Fig. 15 illustrates the candidate route information DB in the state where wavelengths to be used are allocated by first-fit wavelength allocation in this embodiment.

[0072] The route evaluation unit 14 evaluates each candidate route in the candidate route information DB shown in Fig. 17 and determines the route of the optical path. In this embodiment, the route evaluation unit 14 compares the maximum wavelength numbers of the assigned wavelengths of each candidate route and selects the route with the smallest maximum wavelength number. For example, the candidate route information of the second entry in the candidate route information DB shown in Fig. 17 is assigned the smallest maximum wavelength number, 3, and is therefore determined as the route of the optical path.

[0073] (Example of hardware configuration according to this embodiment) The optical path design device 1 can be realized, for example, by causing a computer to execute a program describing the processing content described in this embodiment. Note that this "computer" may be a physical machine or a virtual machine on the cloud. When a virtual machine is used, the "hardware" described here is virtual hardware.

[0074] The above program can be recorded on a computer-readable recording medium (such as a portable memory) and stored or distributed. The above program can also be provided via a network such as the Internet or email.

[0075] Fig. 11 is a diagram showing an example of the hardware configuration of the computer. The computer in Fig. 11 includes a drive device 1000, an auxiliary storage device 1002, a memory device 1003, a CPU 1004, an interface device 1005, a display device 1006, an input device 1007, an output device 1008, and the like, all of which are interconnected via a bus B.

[0076] A program for realizing processing on the computer is provided by a recording medium 1001 such as a CD-ROM or a memory card. When the recording medium 1001 storing the program is set in the drive device 1000, the program is installed from the recording medium 1001 to the auxiliary storage device 1002 via the drive device 1000. However, the program does not necessarily have to be installed from the recording medium 1001, but may be downloaded from another computer via a network. The auxiliary storage device 1002 stores the installed program as well as necessary files, data, etc.

[0077] The memory device 1003 reads and stores a program from the auxiliary storage device 1002 when instructed to start the program. The CPU 1004 implements functions related to the device in accordance with the program stored in the memory device 1003. The interface device 1005 is used as an interface for connecting to a network. The display device 1006 displays a program-based graphical user interface (GUI), etc. The input device 1007 is composed of a keyboard, mouse, buttons, a touch panel, etc., and is used to input various operational instructions. The output device 1008 outputs calculation results. Note that the computer may be equipped with a graphics processing unit (GPU) or tensor processing unit (TPU) instead of the CPU 1004, or may be equipped with a GPU or TPU in addition to the CPU 1004. In this case, processing may be shared, for example, with the GPU or TPU performing processing requiring special calculations and the CPU 1004 performing other processing.

[0078] (Effects of this embodiment) This is possible according to the optical path design device 1 according to this embodiment. This makes it possible to realize an optical path design that allows the modulation method to be changed depending on the transmission quality.

[0079] Specifically, network operators who provide optical transmission networks can enjoy the following benefits: By equalizing wavelength utilization within the optical transmission network, it is possible to delay the timing when additional equipment is required when the same number of optical paths are allocated. By increasing the number of modulation modes available for route calculation, it is possible to propose routes that do not pass through regenerative repeaters. This reduces transmission distances and cuts the costs of equipment and wavelength resources. This is particularly effective when the optical path bit rate is high or the transmission distance is long. By calculating candidate routes for each modulation mode, it is possible to derive routes that meet the conditions for each modulation mode (transmission distance and allowable loss). By periodically updating device information through actual measurements, etc., it is possible to avoid areas where transmission quality deteriorates due to device failure or link degradation, and to select routes with a consistent quality.

[0080] Furthermore, the following effects can be obtained for network users who use the optical transmission network. · An optical path that satisfies the required delay requirement is available. Network operators can use the optical path design apparatus 1 according to this embodiment to reduce the cost of the apparatus, which can lead to a reduction in the cost of using the network and an expansion of other services.

[0081] [References] [1] Jin Y. Yen, "Finding the K Shortest Loopless Paths in a Network,'" Management Science, vol.17, no.11, July 1971. [2] Telecom Infra Project - OOPT PSE Group, "gnpy Documentation,'" Sep. 2021.

[0082] (Summary of the embodiment) This specification describes at least the optical path design device, optical path design method, and program described in the following sections. (Section 1) a transmission quality calculation unit that estimates transmission quality of a plurality of candidate paths in an optical transmission network; a route selection unit that selects a candidate route that satisfies the transmission quality from the plurality of candidate routes, Optical path design device. (Section 2) the route selection unit selects a candidate route having a modulation mode that can be transmitted for a route length of each of the plurality of candidate routes, based on information indicating modulation modes that can be used by devices constituting the optical transmission network. 2. An optical path design device according to claim 1. (Section 3) the transmission quality calculation unit estimates transmission times of the plurality of candidate routes; the route selection unit selects, from the plurality of candidate routes, a candidate route that satisfies a required delay requirement based on the estimated transmission time. 3. An optical path design device according to claim 1 or 2. (Section 4) a route evaluation unit that determines a route that equalizes the wavelength utilization rate from among the plurality of candidate routes selected by the route selection unit, based on information indicating the wavelength utilization status of each route; 3. An optical path design device according to claim 1. (Section 5) a route calculation unit that derives a plurality of candidate routes based on information indicating a positional relationship in the optical transmission network and information indicating requirements for the optical path; the transmission quality calculation unit estimates transmission qualities of the plurality of candidate routes derived by the route calculation unit; 5. An optical path design device according to any one of claims 1 to 4. (Section 6) 1. A computer-implemented optical path design method, comprising: estimating transmission quality of a plurality of candidate paths in an optical transport network; selecting a candidate route that satisfies the transmission quality from the plurality of candidate routes; Optical path design method. (Section 7) A program for causing a computer to function as each unit in the optical path design device according to any one of claims 1 to 5.

[0083] Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0084] 1. Optical path design equipment 10 Route determination unit 11 Route calculation unit 12 Transmission quality calculation unit 13 Route selection section 14 Route evaluation section 20 Memory section 21 Topology Information DB 22 Wavelength information DB 23 Optical path information DB 24 Device information DB 25 Candidate Route Information DB 30 Input / output section 31 Input section 32 Output section 1000 Drive Device 1001 Recording media 1002 Auxiliary storage device 1003 Memory device 1004 CPU 1005 Interface device 1006 Display device 1007 Input Device 1008 Output Device

Claims

1. a transmission quality calculation unit that estimates transmission quality of a plurality of candidate paths in an optical transmission network; a route selection unit that selects a candidate route that satisfies a required transmission quality from the plurality of candidate routes, The route selection unit selecting a candidate route having a modulation mode that can be transmitted for a route length of each of the plurality of candidate routes based on information indicating modulation modes that can be used by devices constituting the optical transmission network; Determine whether the selected candidate route satisfies the optical path delay requirement and the GSNR requirement corresponding to the modulation mode, and delete the route that does not satisfy the requirements from the candidate route. Optical path design device.

2. the transmission quality calculation unit estimates transmission times of the plurality of candidate routes; the route selection unit selects, from the plurality of candidate routes, a candidate route that satisfies a required delay requirement and a required GSNR requirement based on the estimated transmission time. The optical path design device according to claim 1 .

3. a route evaluation unit that determines a route that equalizes the wavelength utilization rate from among the plurality of candidate routes selected by the route selection unit, based on information indicating the wavelength utilization status of each route; 3. The optical path design device according to claim 1.

4. a route calculation unit that derives a plurality of candidate routes based on information indicating a positional relationship in the optical transmission network and information indicating requirements for the optical path; the transmission quality calculation unit estimates transmission qualities of the plurality of candidate routes derived by the route calculation unit; The optical path design device according to any one of claims 1 to 3.

5. 1. A computer-implemented optical path design method, comprising: estimating transmission quality of a plurality of candidate paths in an optical transport network; a route selection step of selecting a candidate route that satisfies a required transmission quality from the plurality of candidate routes, In the route selection step, the computer selecting a candidate route having a modulation mode that can be transmitted for a route length of each of the plurality of candidate routes based on information indicating modulation modes that can be used by devices constituting the optical transmission network; Determine whether the selected candidate route satisfies the optical path delay requirement and the GSNR requirement corresponding to the modulation mode, and delete the route that does not satisfy the requirements from the candidate route. Optical path design method.

6. A program for causing a computer to function as each unit in the optical path design device according to any one of claims 1 to 4.

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