Path selection system and path selection method

Abstract

Provided is a path selection system, which selects an appropriate transmission path in response to a path request, wherein in order to make it possible to select an appropriate transmission path with respect to more path requests, this path selection system includes: an extraction unit that, in response to a path request, extracts transmission paths that satisfy requested quality, from an available transmission network; and an evaluation unit that selects, on the basis of a demand prediction, a transmission path to be provided, from among the extracted transmission paths.

Description

Path selection system and path selection method

[0001] The present invention relates to a path selection system and a path selection method.

[0002] In a transmission network, there is a path selection system that selects an appropriate transmission path in response to a connection request between points (hereinafter referred to as a path request) from a user (see, for example, Non-Patent Document 1).

[0003] Yoshifumi Kato and Masaru Miyoshi, "Proposal of a resource management method for on-demand provision of optical paths," IEICE Technical Report, vol. 122, no. 337, ICM2022-33, pp. 13-18, January 2023, < https: / / ken.ieice.org / ken / paper / 202301192Cqb / >.

[0004] In a transmission network, there is a demand to quickly provide transmission paths in response to as many path requests as possible using limited carrier facility resources.

[0005] A user's path request includes requirements for "network quality" in addition to "connectivity between points." Furthermore, since "network quality" in a transmission network correlates with transmission distance, it is reasonable to connect points via the shortest route in response to a user's path request, as this method can guarantee both connectivity and the network quality desired by the user. This is because, when it comes to network quality requirements that correlate with transmission distance, a network connecting points via the shortest route has the highest "network quality." If this "network quality" does not satisfy the user's network quality requirements, then there is no network that can be provided to meet the user's request.

[0006] However, in this conventional method of connecting bases via the shortest route, specific paths tend to be used frequently depending on the request content or the order in which the requests are made, and if these specific resources (path stock) become depleted, even if there are abundant resources other than these specific paths, it becomes impossible to connect the bases via the shortest route, and an appropriate transmission path cannot be provided. Here, an appropriate transmission path refers to a transmission path that satisfies all of the communication requirements desired by the user.

[0007] The embodiment of the present invention has been made in consideration of the above-mentioned problems, and enables a path selection system that selects an appropriate transmission path in response to a path request to select an appropriate transmission path for a greater number of path requests.

[0008] In order to solve the above problems, a path selection system according to an embodiment of the present invention includes an extraction unit that extracts transmission paths that satisfy a required quality from available transmission networks in response to a path request, and an evaluation unit that selects a transmission path to be provided from the extracted transmission paths based on a demand forecast.

[0009] According to an embodiment of the present invention, in a path selection system that selects an appropriate transmission path in response to a path request, it becomes possible to select an appropriate transmission path for a greater number of path requests.

[0010] 1 is a diagram illustrating an example of the configuration of a path selection system according to the present embodiment; FIG. 2 is a diagram illustrating path information according to the present embodiment; FIG. 3 is a flowchart illustrating an example of a path demand estimation process according to the present embodiment; FIG. 4 is a diagram illustrating an example of a shortest route from site A; FIG. 5 is a diagram illustrating an example of a shortest route from site A; FIG. 6 is a diagram illustrating an example of a shortest route from site A; FIG. 7 is a diagram illustrating an example of a shortest route from site A; FIG. 8 is a diagram illustrating an example of the number of usable paths for each path; FIG. 9 is a flowchart illustrating an example of a path selection process according to the present embodiment; FIG. 10 is a diagram illustrating candidates for transmission paths; FIG. 11 is a diagram illustrating an example of a cost calculation method according to the present embodiment; FIG. 12 is a diagram illustrating transmission paths that satisfy required quality; FIG. 13 is a diagram illustrating an example of transmission paths to be provided; FIG. 14 is a diagram illustrating an example of a computer hardware configuration; FIG. 15 is a diagram illustrating the problem; FIG. 16 is a diagram illustrating the problem; FIG. 17 is a diagram illustrating the problem; FIG. 18 is a diagram illustrating the problem;

[0011] Hereinafter, an embodiment of the present invention 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.

[0012] <About the Path Selection System> The path selection system is a system that selects an appropriate transmission path in response to a path request that requests the selection of a transmission path between bases in a transmission network. In this embodiment, the entire end-to-end transmission path between two bases to be selected is called a "transmission path," and a transmission path between any bases is simply called a "path."

[0013] As a specific example, the transmission paths and paths are, for example, optical paths in an optical network, and the path selection system is included in, for example, a service order system that manages service orders such as optical path opening orders, change orders, and / or deletion orders. However, this is just an example, and the transmission paths and paths are not limited to optical paths, and the path selection system may be a system separate from the service order system.

[0014] (Regarding Issues) Before describing the path selection system according to this embodiment, issues with conventional transmission path selection methods will be described. Figures 18 to 20 are diagrams for explaining the issues.

[0015] Fig. 18 shows an example of topology information for a transmission network 1. In Fig. 18, A to I are bases, and the lines between the bases indicate paths. The numerical values ​​written near each path indicate the transmission distance (km) between the bases, and the inventory of each path (edge) is assumed to be 1. In a transmission network, there is a correlation between the transmission distance between bases and communication quality, so for convenience, the transmission distance between bases is treated here as communication quality.

[0016] For example, suppose a first path request between site A and site I is received, and the required quality is "the total distance of the transmission path is 70 km or less." In this case, when selecting the shortest transmission path, for example, the transmission path 10 "A-D-G-I" that satisfies the required quality and has the shortest total distance is selected, as shown in FIG.

[0017] However, this method has a problem in that, for example, when a second path request between site B and site I is subsequently received and the required quality is "a total distance of the transmission paths of 70 km or less," it is not possible to select a transmission path that satisfies the required quality. For example, in FIG. 20, the transmission path "B-D-G-I" is required to satisfy the required quality of the second path request. However, because the transmission path 10 "A-D-G-I" has been selected for the first path request, the path inventory runs out, and it is not possible to provide the transmission path "B-D-G-I" that satisfies the required quality for the second path request.

[0018] 21, if the transmission path 11 "A-D-F-I" is selected for the first path request, the transmission path 12 "A-D-G-I" can be selected for the second path request. However, when the first path request is accepted, the subsequent second path request is unknown, so it is difficult to determine the critical path in the second path request.

[0019] As described above, the conventional technology has a problem in that, depending on the request content or the order in which the requests are made, a specific path resource may be depleted, making it impossible to provide an appropriate transmission path.

[0020] Therefore, in order to solve the above problem, the path selection system according to this embodiment has a configuration such as that shown in FIG.

[0021] <Configuration of Path Selection System> Fig. 1 is a diagram showing an example of the configuration of a path selection system according to this embodiment. In the example of Fig. 1, a path selection system 100 includes a path selection device 110 and a path information collection device 120.

[0022] The path selection device 110 is an information processing device having a computer configuration or a system including multiple computers. The path selection device 110 realizes, for example, each functional configuration shown in FIG. 1 by the computer included in the path selection device 110 executing a predetermined program stored in a storage medium.

[0023] 1, the path selection device 110 has various functional components, such as an estimation unit 111, a path information management DB (Database) 112, a request reception unit 113, an extraction unit 114, an evaluation unit 115, and a request response unit 116. Note that at least a portion of the above-described functional components may be realized by hardware.

[0024] The estimation unit 111 executes an estimation process of estimating an index indicating relative path demand for each path in the transmission network based on path information (topology information) of the available transmission network, and storing the index in the path information management DB 112, etc. Here, the index indicating relative path demand is an index such as the congestion degree (or margin degree) that is predetermined so as to be able to identify paths that are expected to have high demand, such as the path between bases D and G and the path between bases G and I described in FIG.

[0025] If there is a certain amount of past demand history, it is possible to identify paths with high demand from bus usage history. However, for example, in a new transmission network that is still in its infancy, or in a network where new equipment has been introduced, an estimation method that does not rely on past history is required.

[0026] Furthermore, the path information (topology information) used in the estimation process is not limited to the small-scale transmission network 1 shown in Fig. 18, but may include path information of large-scale transmission networks such as the entire Japan 200, the Kansai region 201, or the Kanto region 202, as shown in Fig. 2. Therefore, the estimation unit 111 is required to be able to estimate an index indicating relative path demand using a general-purpose method that can be applied to large-scale path information. Note that a specific method for estimating an index indicating relative path demand by the estimation unit 111 will be described later.

[0027] The path information management DB 120 is a database that stores, for example, path information (topology information) of available transmission networks collected by the path information collection device 120, and indicators indicating the relative path demand of each path estimated by the estimation unit 111. The path information management DB 120 may be provided outside the path selection device 110.

[0028] The request receiving unit 113 executes a request receiving process to receive a path request from a user requesting the selection (or provision) of a transmission path. The path request includes, for example, information on the total distance between paths or the required quality such as communication quality. The user may also be another system or an information terminal.

[0029] The extraction unit 114 executes extraction processing to extract a transmission path that satisfies the required quality from an available transmission network in response to the path request received by the request reception unit 113. For example, the extraction unit 114 calculates the first to kth shortest transmission paths (k is an integer equal to or greater than 2) using a known algorithm such as k-shortest path. Furthermore, the extraction unit 114 extracts a transmission path that satisfies the required quality by excluding transmission paths that do not satisfy the required quality from the calculated transmission paths.

[0030] The evaluation unit 115 executes an evaluation process to select a transmission path to be provided from among the transmission paths extracted by the extraction unit 114 based on a demand forecast. For example, the evaluation unit 115 selects a transmission path to be provided based on an index estimated by the estimation unit 111 and stored in the path information management DB 112. As a specific example, the evaluation unit 115 calculates the cost of the extracted transmission path based on an index indicating the relative path demand of each path included in the extracted transmission path, and selects a transmission path with a lower cost. As another example, the evaluation unit 115 calculates the cost of the extracted transmission path based on an index indicating the relative path demand of each path included in the extracted transmission path and inventory information for each path, and selects a transmission path to be provided based on the calculated cost.

[0031] The request response unit 116 executes a request response process to transmit a path response including information on the transmission path selected by the evaluation unit 115 to the user who transmitted the path request.

[0032] The configuration of the path selection system 100 shown in Fig. 1 is an example. For example, in Fig. 1, the functional components of the path selection device 110 may be distributed across multiple devices. Furthermore, the path information collection device 120 may be an external device or system to the path selection system 100. Furthermore, the functional components of the path selection device 110 are not limited to physical machines, and may be realized by a program executed on a virtual machine on a cloud, for example.

[0033] <Processing Flow> Next, the processing flow of the path selection method according to this embodiment will be described.

[0034] (Path Demand Estimation Process) Fig. 3 is a flowchart showing an example of a path demand estimation process according to this embodiment. This process shows an example of a path demand estimation process executed by the estimation unit 111 as a preliminary preparation for the path selection process described in Fig. 12. It is assumed that at the start of the process of Fig. 3, path information of available transmission networks is stored in the path information management DB 112. The path information of the transmission network includes, for example, topology information of the transmission network, distance information of each path, and the number of times each path can be used (path inventory number).

[0035] In step S301, the estimation unit 111 connects all the nodes with the shortest route or the route with the highest quality based on the path information (topology information) of the transmission network.

[0036] 4 shows an example of path information (topology information) for a transmission network 400. In FIG. 4, A to I are base stations, and the lines between the base stations indicate paths. The numerical values ​​written near each path indicate the transmission distance (km) between the base stations.

[0037] For example, as shown in Fig. 4, the estimation unit 111 connects between base A and base B via the shortest route 401. Furthermore, as shown in Fig. 5, the estimation unit 111 connects between base A and base C via the shortest route 501. Note that as shown in Fig. 5, base A and base D are already connected via the shortest distance. Next, as shown in Fig. 6, the estimation unit 111 connects between base A and base E via the shortest distance 601.

[0038] Next, the estimation unit 111 connects the base A and the base F with the shortest route 701, as shown in Fig. 7. Furthermore, the estimation unit 111 connects the base A and the base G with the shortest route 801, as shown in Fig. 8. Furthermore, the estimation unit 111 connects the base A and the base H with the shortest route 901, as shown in Fig. 9. Furthermore, the estimation unit 111 connects the base A and the base I with the shortest route 1001, as shown in Fig. 10.

[0039] 4 to 10, the estimation unit 111 can connect the location A with the other locations B to I via the shortest route. Similarly, the estimation unit 111 connects each of the locations B to I with the other locations via the shortest route.

[0040] 3, the estimation unit 111 counts the number of times each path is used in the process of step S301. For example, as shown in FIG. 11, the estimation unit 111 counts the number of shortest paths connected in the process of step S301 for each path.

[0041] 11 shows that the path between sites A and D was used 8 times, the path between sites B and D 8 times, the path between sites C and D 8 times, the path between sites D and E 5 times, the path between sites D and F 5 times, the path between sites D and G 11 times, and the path between sites D and H 5 times. Also, the example of Fig. 11 shows that the path between sites E and I was used 3 times, the path between sites F and I 3 times, the path between sites G and I 5 times, and the path between sites H and I 3 times.

[0042] In step S303 of FIG. 3, the estimation unit 111 stores the number of times each path is used, counted in step S302, in the path information management DB 112 or the like as an estimate of the relative path demand.

[0043] By the processing of Figure 3, the estimation unit 111 can estimate an index indicating the relative path demand for each path in the transmission network 400 based on the path information (topology information) of the transmission network 400 and store it in the path information management DB 112.

[0044] (Path Selection Process) Fig. 12 is a flowchart showing an example of the path selection process according to this embodiment. This process shows an example of the path selection process executed by the path selection device 110 when the request receiving unit 113 receives a path request. It is assumed that the path demand estimation process described in Fig. 3 has already been executed at the start of the process in Fig. 12.

[0045] In step S1201, when the request receiving unit 113 receives a path request, the path selection device 110 executes the processes from step S1202 onwards.

[0046] In step S1202, the extraction unit 114 extracts transmission paths (transmission path candidates) that satisfy the required quality from the available transmission networks.

[0047] For example, in a transmission network 1300 as shown in FIG. 13, a transmission path between point A and point I is required, and the required quality is that the total distance of the transmission path is 70 km or less. In this case, the extraction unit 114 finds candidates for the transmission path using, for example, a known algorithm such as the k-shortest path. As described above, the k-shortest path is an algorithm that calculates the first to kth shortest transmission paths. In order to limit the amount of calculation, the extraction unit 114 may arbitrarily set an upper limit (k) value for the number of candidates for the transmission path.

[0048] As a result, the extraction unit 114 can extract, for example, four routes "ADEI", "ADFI", "ADGI", and "ADHI" as candidate transmission paths, as shown in FIG. 13.

[0049] Furthermore, the extraction unit 114 excludes the route "A-D-E-I" that does not satisfy the required quality from the extracted transmission path candidates. As a result, the extraction unit 114 can extract the three routes "A-D-F-I," "A-D-G-I," and "A-D-H-I" as transmission paths (transmission path candidates) that satisfy the required quality.

[0050] 12, the evaluation unit 115 selects a transmission path having a lower demand from the extracted transmission paths. For example, the evaluation unit 115 calculates the cost of the extracted transmission paths based on an index indicating the relative path demand of each path stored in the path information management DB 112, and selects the transmission path having the lower calculated cost.

[0051] Fig. 14 is a diagram showing an example of a cost calculation method according to this embodiment. The evaluation unit 115 calculates the cost of the extracted transmission path by using one of the cost calculation methods shown in Fig. 14 or a combination of the cost calculation methods shown in Fig. 14.

[0052] Here, the congestion index is an index that increases as the relative path demand increases. For example, the number of times each path is used, counted in step S302 of FIG. 3, can be used as the congestion index. The congestion index is an example of an index that indicates relative path demand. For example, the index that indicates relative path demand may be a margin index or the like that increases as the relative path demand decreases.

[0053] Preferably, the evaluation unit 115 calculates the cost of the extracted transmission path based on an index indicating the relative path demand of each path and inventory information of each path. This allows a mechanism to be implemented in which even if there is a path with a low degree of congestion, if the inventory is low, the path is reflected in the cost as a rare path and is not adopted.

[0054] For example, when the costs of the extracted transmission paths are calculated using min (congestion) with reference to Fig. 11, the result is as shown in Fig. 15. In this case, the evaluation unit 115 excludes the route "A-D-G-I" with the higher cost from the candidates for the transmission path. Furthermore, the evaluation unit 115 selects the route "A-D-H-I" with the higher ranking of the two remaining transmission paths as the transmission path configured with the path with the least demand.

[0055] 12, the request response unit 116 provides the requester of the path request with information about the transmission path selected by the evaluation unit 115. For example, the request response unit 116 transmits a path response including information about a transmission path 1601 passing through the route "A-D-H-I" as shown in FIG. 16 to the user who transmitted the path request.

[0056] By the processing of Figure 12, the path selection system 100 can extract transmission paths that meet the required quality from the available transmission network in response to a path request, and select a transmission path that is composed of paths with less demand from among the extracted transmission paths.

[0057] <Hardware Configuration Example> (Hardware Configuration of Path Selection Device) The path selection device 110 has, for example, a computer hardware configuration as shown in Fig. 17. Alternatively, the path selection device 110 is realized by a plurality of computers.

[0058] Fig. 17 is a diagram showing an example of the hardware configuration of a computer. In the example of Fig. 17, a computer 1700 includes a processor 1701, a memory 1702, a storage device 1703, a communication device 1704, an input device 1705, an output device 1706, a bus B, etc.

[0059] The processor 1701 is, for example, an arithmetic unit such as a CPU (Central Processing Unit) that executes predetermined programs to realize various functions. The memory 1702 is a storage medium readable by the computer 1700, and includes, for example, a RAM (Random Access Memory) and a ROM (Read Only Memory). The storage device 1703 is a computer-readable storage medium, and may include, for example, a HDD (Hard Disk Drive), an SSD (Solid State Drive), various optical disks, and magneto-optical disks.

[0060] The communication device 1704 includes one or more pieces of hardware (communication devices) for communicating with other devices via a wireless or wired network. The input device 1705 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1706 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that outputs to the outside.

[0061] The bus B is commonly connected to the above components and transmits, for example, address signals, data signals, and various control signals. The processor 1701 is not limited to a CPU, and may be, for example, a DSP (Digital Signal Processor), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

[0062] (Supplementary Note) The path selection device 110 in this embodiment is not limited to being realized by a dedicated device, but may also be realized by a general-purpose computer. In this case, a program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read into a computer system and executed. Note that the term "computer system" here includes hardware such as an OS and peripheral devices.

[0063] Furthermore, "computer-readable recording media" includes various storage devices such as portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, as well as hard disks built into computer systems. Furthermore, "computer-readable recording media" may also include devices that dynamically store programs for a short period of time, such as communication lines when transmitting programs via networks such as the Internet or communication lines such as telephone lines, and devices that store programs for a certain period of time, such as volatile memory within computer systems that serve as servers or clients in such cases.

[0064] Furthermore, the above program may be one that realizes part of the above-mentioned functions, or may be one that can realize the above-mentioned functions in combination with a program already recorded in a computer system, or may be one that is realized using hardware such as a PLD (Programmable Logic Device) or FPGA (Field Programmable Gate Array).

[0065] <Effects of the embodiment> According to the present embodiment, the path selection system 100 that selects an appropriate transmission path in response to a path request can select an appropriate transmission path for a larger number of path requests.

[0066] For example, the path selection system 100 according to this embodiment can instantly provide transmission paths to more path requests in a transmission network using limited carrier facility resources.

[0067] Summary of Embodiments This specification discloses at least the following path selection systems and path selection methods: (1) A path selection system comprising: an extraction unit that extracts transmission paths that satisfy a required quality from an available transmission network in response to a path request; and an evaluation unit that selects a transmission path to be provided from the extracted transmission paths based on a demand forecast. (2) The path selection system according to paragraph 1, comprising: an estimation unit that estimates an index indicating relative path demand for each path in the transmission network based on topology information of the transmission network, and the evaluation unit selects the transmission path to be provided based on the index. (3) The path selection system according to paragraph 1 or 2, wherein the evaluation unit calculates the cost of the extracted transmission path based on an index indicating the relative path demand of each path included in the extracted transmission paths and inventory information for each path, and selects the transmission path to be provided based on the cost. (Clause 4) A path selection method in which a computer executes: an extraction process for extracting a transmission path that satisfies the required quality from an available transmission network in response to a path request; and an evaluation process for selecting a transmission path to be provided from the extracted transmission paths based on a demand forecast. (Clause 5) A program or a storage medium storing the program, which is executed by a computer to perform the path selection method described in clause 4. (Clause 6) A path selection device having: an extraction unit that extracts a transmission path that satisfies the required quality from an available transmission network in response to a path request; and an evaluation unit that selects a transmission path to be provided from the extracted transmission paths based on a demand forecast.

[0068] 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.

[0069] 100 Path selection system 110 Path selection device 111 Estimation unit 114 Extraction unit 115 Evaluation unit 1700 Computer

Claims

1. A path selection system having: an extraction unit that extracts transmission paths that meet the required quality from available transmission networks in response to a path request; and an evaluation unit that selects a transmission path to be provided from the extracted transmission paths based on a demand forecast.

2. The path selection system according to claim 1, further comprising an estimation unit that estimates an index indicating relative path demand for each path of the transmission network based on topology information of the transmission network, and the evaluation unit selects the transmission path to be provided based on the index.

3. A path selection system as described in claim 1 or 2, wherein the evaluation unit calculates the cost of the extracted transmission path based on an index indicating the relative path demand of each path included in the extracted transmission path and inventory information for each path, and selects the transmission path to be provided based on the cost.

4. A path selection method in which a computer executes an extraction process to extract transmission paths that satisfy the required quality from available transmission networks in response to a path request, and an evaluation process to select a transmission path to be provided based on a demand forecast from among the extracted transmission paths.

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