WO2023248316A1 - Route search device, route search method, and program - Google Patents

Route search device, route search method, and program Download PDF

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Publication number
WO2023248316A1
WO2023248316A1 PCT/JP2022/024614 JP2022024614W WO2023248316A1 WO 2023248316 A1 WO2023248316 A1 WO 2023248316A1 JP 2022024614 W JP2022024614 W JP 2022024614W WO 2023248316 A1 WO2023248316 A1 WO 2023248316A1
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Prior art keywords
route
candidate routes
candidate
links
optical path
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PCT/JP2022/024614
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French (fr)
Japanese (ja)
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花深 横井
弘順 越地
達哉 松川
崇 宮村
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日本電信電話株式会社
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Priority to PCT/JP2022/024614 priority Critical patent/WO2023248316A1/en
Publication of WO2023248316A1 publication Critical patent/WO2023248316A1/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L45/00—Routing or path finding of packets in data switching networks
    • H04L45/12—Shortest path evaluation

Definitions

  • the present invention relates to a route searching device, a route searching method, and a program in an optical transmission network.
  • optical transmission network communication data is handled using light, and the communication demands that exist within the optical transmission network are called optical paths.
  • optical path wavelength allocation methods and route calculation methods are being studied.
  • Non-Patent Document 1 As a conventional technique of the route calculation method, there is a technique disclosed in Non-Patent Document 1.
  • Non-Patent Document 1 by selecting a path with a small maximum usage wavelength number when designing an optical path, the wavelength usage efficiency is improved by reducing the maximum usage wavelength number. Specifically, after finding a plurality of candidate routes and searching for wavelengths that can be used for each candidate route, the candidate route with the smallest maximum usage wavelength number is adopted as the usage route.
  • the largest wavelength number corresponding to the wavelength of the wavelength-multiplexed optical signal on the path is defined as the maximum wavelength number used.
  • Non-Patent Document 1 by dispersing the routes used by optical paths, it is possible to reduce the bias in the wavelength utilization rate of each link and improve the wavelength utilization rate of the entire optical transmission network.
  • the following problems may occur depending on the number of candidate routes.
  • Figure 1 shows the relationship between the number of candidate routes K and the maximum usage wavelength number selected by optical path design (solid line), and the relationship between the number of candidate routes K and the execution time per path of optical path design (dashed line) in an example of an optical transmission network.
  • FIG. 1 when the number K of candidate routes is 2, the effect of the optical path design is not fully demonstrated, and when the number K of candidate routes is 20, the effect of the optical path design is not fully demonstrated. A problem occurs where the execution time per pass becomes long.
  • An object of the present invention is to provide a route search device that can maximize the effect of light path design and shorten execution time when searching for a route using an optical path design method that uses a plurality of candidate routes. .
  • the optical path route search device for an optical transmission network of the present invention includes an optimal candidate route number derivation unit that derives the number of candidate routes for route searching based on information in a topology parameter DB of the optical transmission network. Then, candidate routes for the number of candidate routes derived by the optimal candidate route number derivation section are obtained, and among the candidate routes obtained, the route with the smallest maximum usage wavelength number in wavelength division multiplexing is set as the usage route, and the maximum usage wavelength is set as the usage route.
  • the optical path design unit assigns a number to an optical path to be set.
  • a route search device when a route search device performs a route search using an optical path design method using a plurality of candidate routes, it is possible to maximize the effect of optical path design and shorten the execution time.
  • FIG. 7 is a diagram showing the relationship between the number of candidate routes and the maximum usage wavelength number selected by optical path design, and the relationship between the number of candidate routes and the execution time of optical path design.
  • FIG. 1 is a diagram showing the configuration of a route search device according to an embodiment.
  • FIG. 2 is a hardware configuration diagram showing an example of a computer that implements the functions of the route search device according to the embodiment. It is a flow diagram explaining operation of a route search device of an embodiment.
  • 1 is a diagram illustrating an example of an optical transmission network that performs route search for optical paths;
  • FIG. It is a diagram showing an example of the configuration of a topology information DB.
  • FIG. 2 is a diagram illustrating the configuration of a topology parameter DB.
  • FIG. 2 is a diagram showing the state of an optical transmission network when setting up an optical path.
  • FIG. 3 is a diagram showing a first candidate route. It is a figure which shows the second candidate route. It is a figure which shows the third candidate route
  • FIG. 2 is a diagram showing the configuration of a route search device 1 according to an embodiment that determines optical path routes and wavelength assignments in the optical transmission network 7. As shown in FIG.
  • the optical transmission network 7 is a backbone network such as an IP communication network that realizes communication using optical signals, and connects nodes using optical fibers that transmit wavelength-multiplexed optical signals (hereinafter referred to as links).
  • an optical path network is configured by optical paths that are set up via one or more nodes.
  • the route search device 1 of the embodiment includes an optical path design unit 3 that determines the optimal optical path route and wavelength assignment using the technology described in Non-Patent Document 1, and an optical path design unit 3 that derives the number of candidate routes.
  • the optimum candidate route number deriving unit 2 controls the nodes by a node control device (not shown) to set optical paths of the optical transmission network 7.
  • the optimal candidate route number deriving unit 2 includes a topology parameter deriving unit 21, which will be described in detail later, and a candidate route number calculating unit 22.
  • the route search device 1 of the embodiment also includes a topology information DB 41 that stores topology information including information indicating connection relationships between nodes and links in an optical transmission network and distances between nodes, and
  • the storage unit 4 includes a topology parameter DB 42 that stores parameters used for deriving the number of optimal candidate routes.
  • the configurations of the topology information DB 41 and topology parameter DB 42 will be described later.
  • the route search device 1 of the embodiment includes an input unit 5 that inputs topology information used for optical path design, and an output unit 6 that outputs execution results of various functions.
  • the route search device 1 of the embodiment is realized by a computer 300 having a configuration as shown in FIG. 3, for example.
  • FIG. 3 is a hardware configuration diagram showing an example of a computer 300 that implements the functions of the route search device 1 of the embodiment.
  • the computer 300 includes a CPU (Central Processing Unit) 301, a ROM (Read Only Memory) 302, a RAM 303, an HDD (Hard Disk Drive) 304, an input/output I/F (Interface) 305, a communication I/F 306, and a media I/F 307. have a CPU (Central Processing Unit) 301, a ROM (Read Only Memory) 302, a RAM 303, an HDD (Hard Disk Drive) 304, an input/output I/F (Interface) 305, a communication I/F 306, and a media I/F 307.
  • a CPU Central Processing Unit
  • ROM Read Only Memory
  • RAM random access memory
  • HDD Hard Disk Drive
  • I/F Interface
  • the CPU 301 operates based on a program stored in the ROM 302 or HDD 304, and performs control by the control unit.
  • the ROM 302 stores a boot program executed by the CPU 301 when the computer 300 is started, programs related to the hardware of the computer 300, and the like.
  • the CPU 301 controls an input device 310 such as a mouse or a keyboard, and an output device 311 such as a display or printer via an input/output I/F 305.
  • the CPU 301 acquires data from the input device 310 via the input/output I/F 305 and outputs the generated data to the output device 311.
  • a GPU Graphics Processing Unit
  • a GPU Graphics Processing Unit or the like may be used in addition to the CPU 301 as the processor.
  • the HDD 304 stores programs executed by the CPU 301 and data used by the programs.
  • the communication I/F 306 receives data from other devices via a communication network (for example, NW (Network) 320) and outputs it to the CPU 301, and also sends data generated by the CPU 301 to other devices via the communication network. Send to device.
  • NW Network
  • the media I/F 307 reads the program or data stored in the recording medium 312 and outputs it to the CPU 301 via the RAM 303.
  • the CPU 301 loads a program related to target processing from the recording medium 312 onto the RAM 303 via the media I/F 307, and executes the loaded program.
  • the recording medium 312 is an optical recording medium such as a DVD (Digital Versatile Disc) or a PD (Phase change rewritable disk), a magneto-optical recording medium such as an MO (Magneto Optical disk), a magnetic recording medium, a semiconductor memory, or the like.
  • the CPU 301 of the computer 300 executes the program loaded on the RAM 303 to connect the optimal candidate route number deriving unit 2 of the route searching device 1.
  • the functions of the optical path design section 3 are realized.
  • the HDD 304 functions as a storage unit 4 that stores a topology information DB 41 and a topology parameter DB 42, and also stores data in the RAM 303.
  • the CPU 301 reads a program related to the target process from the recording medium 312 and executes it.
  • the CPU 301 may read a program related to target processing from another device via a communication network (NW 320).
  • step S41 the topology parameter derivation unit 21 (see FIG. 2) of the optimal candidate route number derivation unit 2 derives parameters necessary for determining the number of candidate routes based on the information stored in the topology information DB 41, It is stored in the topology parameter DB 42.
  • step S42 the candidate route number calculation unit 22 derives an optimal value for the number of candidate routes to be evaluated by the optical path design unit 3, based on the topology parameter DB 42, using a derivation method that will be described in detail later.
  • step S43 the optical path design unit 3 obtains candidate routes equal to the number of candidate routes calculated by the candidate route number calculation unit 22 in step S42, and as in the technique of Non-Patent Document 1, Optical path routes and wavelengths that improve the wavelength utilization of the entire optical transmission network are determined by considering the continuity of wavelengths across links. Details will be described later.
  • step S44 the route search device 1 controls a node control device (not shown) to create an optical path in the optical transmission network 7 based on the optical path route and wavelength assignment determined by the optical path design unit 3. Set.
  • the optimal candidate route number deriving unit 2 (candidate route number calculating unit 22) will be explained in more detail.
  • the configurations of the topology information DB 41 and topology parameter DB 42 referred to by the optimal candidate route number deriving unit 2 will be explained.
  • FIG. 5 is a diagram showing an example of an optical transmission network 7 in which the route search device 1 searches for an optical path.
  • the black circles in FIG. 5 indicate arranged stations (hereinafter sometimes referred to as nodes), and the numbers attached to the black circles indicate node numbers indicating the stations. Further, the solid line in FIG. 5 indicates a transmission path (hereinafter sometimes referred to as a link) using an optical fiber between stations.
  • the optical transmission network 7 is configured by connecting a plurality of nodes with links.
  • the route search device 1 (optical path design unit 3) determines the continuity of wavelengths across multiple links of the optical transmission network 7, constraints brought about by optical transmission deterioration factors, redundancy for high reliability of optical paths, etc. Considering this, we design optical paths according to the traffic demand between nodes and construct an optical path network.
  • FIG. 6 is a diagram showing an example of the configuration of the topology information DB 41 that holds information indicating connection relationships of nodes, links, etc. of the optical transmission network 7 shown in FIG. 5.
  • the topology information DB 41 includes a node A number 411 indicating the node number of the starting point node for each link of the optical transmission network 7, a node Z number 412 indicating the node number of the ending node, a link distance 413, and a link number 414 for identifying the link. Consists of.
  • FIG. 7 is a diagram illustrating the configuration of the topology parameter DB 42 derived by the topology parameter derivation unit 21 of the optimal candidate route number derivation unit 2 as parameters necessary for determining the number of candidate routes based on the information in the topology information DB 41. be.
  • the topology parameters define parameters for the optical transmission network 7 based on graph theory.
  • the number of nodes 421 indicates the number of nodes in the optical transmission network 7 shown in FIG.
  • nodes are points in graph theory.
  • the number of links 422 indicates the number of links in the optical transmission network 7 shown in FIG.
  • the average degree 423 indicates the average value of degrees (number of edges connected to vertices of the graph) corresponding to the number of links connected to a certain node of the optical transmission network 7.
  • the degree of connectivity 424 indicates the number of nodes that need to be removed in order to disconnect the optical transmission network 7, which is a connected graph.
  • the average connectivity degree 425 indicates the average value of the connectivity degrees 424.
  • the edge connectivity 426 indicates the number of links that need to be removed in order to disconnect the optical transmission network 7, which is a connected graph.
  • Betweenness centrality (average) 427 is the average value of betweenness centrality values, which is the ratio of the shortest paths connecting a certain node A and two other nodes that pass through a certain node A.
  • Betweenness centrality (maximum) 428 is the maximum value of betweenness centrality, which is the ratio of the shortest paths connecting a certain node A and two other nodes that pass through a certain node A.
  • the candidate route number calculation unit 22 refers to the topology parameter DB 42, and the optical path design unit 3 derives the number of candidate routes using one of the following calculation formulas.
  • Number of candidate routes number of links / average degree ... (1)
  • Number of candidate routes number of links ⁇ betweenness centrality (maximum) ...
  • Number of candidate routes number of links ⁇ average degree ⁇ betweenness centrality (average) ...
  • the candidate route number calculation unit 22 calculates the number of candidate routes using each of equations (1) to (3), and calculates the minimum value of the calculated number of candidate routes to the candidate route calculated by the number of candidate route calculation unit 22. It may be a number.
  • the candidate route number calculation unit 22 refers to the topology parameter DB 42 and calculates the number of candidate routes using equation (1).
  • the optical path design unit 3 calculates routes from the start node to the destination node for the number of candidate routes calculated as described above by the candidate route number calculation unit 22, and calculates the routes from the start node to the end node as many as the number of candidate routes calculated by the candidate route number calculation unit 22 as described above.
  • the optimal optical path is determined according to the traffic demand between nodes, taking into account factors such as performance, constraints brought about by optical transmission deterioration factors, and redundancy to increase the reliability of the optical path.
  • optical path determination method of the optical path design unit 3 will be explained with reference to FIGS. 8, 9A, 9B, and 9C.
  • FIG. 8 is a diagram showing the state of the optical transmission network when setting an optical path.
  • the node S is the starting point node of the optical path
  • the node D is the ending point node of the optical path.
  • each link is an optical fiber that transmits an optical signal that has been wavelength-multiplexed and divided into six wavelengths, and the used wavelength and unused wavelength of the wavelength number of each link are shown.
  • optical path design unit 3 adds an optical path from node S to node D. (set).
  • the optical path design unit 3 calculates the three candidates shown in FIGS. 9A, 9B, and 9C Find a route.
  • the optical path design unit 3 uses, for example, the K-Shortest Path algorithm to find three candidate paths in order of the shortest path.
  • the optical path design unit 3 selects the wavelength of wavelength number 6 as the wavelength to be used in the candidate route a of FIG. Find a.
  • optical path design unit 3 can select wavelengths with wavelength numbers 5 and 6 in candidate route b in FIG. 9B, and can select wavelengths with wavelength numbers 5 and 6 in candidate route b and Find the optical path b2 of No. 6.
  • the optical path design unit 3 can select wavelengths with wavelength numbers 3 and 4 in the candidate route c in FIG. 9C, and select the optical path c1 with the wavelength number 3 in the candidate route c, and Find the optical path c2 of 4.
  • wavelength numbers 5 and 6 can also be used, wavelength numbers 3 and 4 will be used here.
  • the optical path design unit 3 determines the maximum usage of the wavelength number corresponding to the wavelength of the wavelength-multiplexed optical signal in the three candidate routes a, b, and c in FIGS. 9A, 9B, and 9C.
  • the candidate route c in FIG. 9C with the smallest wavelength number is set as the route to be used, and the wavelength with wavelength number 3 is assigned to the optical path to be added.
  • the optical path design unit 3 determines candidate routes for the number of candidate routes derived by the optimal candidate route number derivation unit 2, and selects the route with the smallest maximum used wavelength number in wavelength division multiplexing among the determined candidate routes. is used as the route to be used, and its maximum used wavelength number is assigned to the optical path to be set. As a result, it is possible to reduce the bias in the wavelengths used and increase the number of optical paths that can be accommodated, so it is possible to improve the wavelength utilization rate of the entire optical transmission network.
  • the route search device 1 is a route search device 1 for optical paths in an optical transmission network, and is an optimal candidate route for deriving the number of candidate routes for route searching based on information in the topology parameter DB 42 of the optical transmission network.
  • the number deriving unit 2 and the optimal candidate route number deriving unit 2 calculate candidate routes for the number of candidate routes derived, and among the candidate routes found, the route with the smallest maximum used wavelength number in wavelength division multiplexing is set as the usage route, and
  • the present invention is characterized by comprising an optical path design unit 3 that assigns a maximum usage wavelength number to an optical path to be set.
  • the optimal number of candidate routes deriving unit 2 calculates the number of candidate routes by dividing the number of links 422 by the average degree 423 based on the number of links 422 and the average degree 423 of the topology parameter DB 42. Further, the optimum number of candidate routes deriving unit 2 calculates the number of candidate routes by multiplying the number of links 422 by the maximum value of betweenness centrality of 428, based on the number of links 422 of the topology parameter DB 42 and the maximum value of betweenness centrality of 428. Calculate.
  • the optimal candidate route number deriving unit 2 calculates the number of links 422, the average degree 423, and the average betweenness centrality 427 based on the values of the number of links 422, the average degree 423, and the average betweenness centrality 427 of the topology parameter DB 42.
  • the number of candidate routes is calculated by multiplying by the value of .
  • the optimum number of candidate routes deriving unit 2 can easily calculate the number of candidate routes, so it is possible to reduce the calculation resources used for deriving the number of candidate routes.

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Abstract

The present invention provides a route search device (1) which is for an optical path of an optical transmission network and which comprises: an optimal candidate route number derivation unit (2) that derives the number of candidate routes for which route searching is performed, on the basis of information of a topology parameter DB (42) of an optical transmission network; and an optical path design unit (3) that determines candidate routes of the number of candidate routes derived by the optimal candidate route number derivation unit, that sets a usage route to be the route among the determined candidate routes which has the smallest maximum used wavelength number in wavelength division multiplexing, and that assigns the maximum used wavelength number thereof to an optical path to be set. Specifically, on the basis of a number (422) of links , an average degree (423), the maximum (427) value of betweenness centrality, and the average (428) value of betweenness centrality, which are the information of the topology parameter DB (42), the number of candidate routes is derived by dividing the number of links by the average degree, multiplying the number of links by the maximum value of the betweenness centrality, or multiplying the number of links by the average degree and the average value of the betweenness centrality.

Description

経路探索装置、経路探索方法及びプログラムRoute searching device, route searching method and program
　本発明は、光伝送ネットワークにおける経路探索装置、経路探索方法及びプログラムに関する。 The present invention relates to a route searching device, a route searching method, and a program in an optical transmission network.
　近年、ますますインターネットのトラフィックは増加しており、光伝送ネットワークの高速大容量化だけでなく、光伝送ネットワークの効率的な利用が求められている。光伝送ネットワーク内では、通信データは光で扱われ、光伝送ネットワーク内に存在する通信需要は光パスと呼ばれる。この光パスの収容効率を向上させるために，光パスの波長割当方式や経路計算方式が検討されている。 In recent years, Internet traffic has been increasing more and more, and there is a demand for not only higher speed and larger capacity optical transmission networks, but also efficient use of optical transmission networks. Within an optical transmission network, communication data is handled using light, and the communication demands that exist within the optical transmission network are called optical paths. In order to improve the efficiency of accommodating optical paths, optical path wavelength allocation methods and route calculation methods are being studied.
　経路計算方式の従来技術として、非特許文献１の技術がある。
　非特許文献１では、光パス設計時に最大使用波長番号の小さい経路を選択することにより、最大使用波長番号の低減による波長利用効率の向上を図るものである。具体的には、複数の候補経路を求め、各候補経路に対して利用可能な波長を探索後に、最大使用波長番号が最小の候補経路を利用経路として採用する。なお、本明細書では、経路における波長多重分割した光信号の波長に対応する波長番号のうち最大のものを最大使用波長番号としている。 As a conventional technique of the route calculation method, there is a technique disclosed in Non-Patent Document 1.
In Non-Patent Document 1, by selecting a path with a small maximum usage wavelength number when designing an optical path, the wavelength usage efficiency is improved by reducing the maximum usage wavelength number. Specifically, after finding a plurality of candidate routes and searching for wavelengths that can be used for each candidate route, the candidate route with the smallest maximum usage wavelength number is adopted as the usage route. In this specification, the largest wavelength number corresponding to the wavelength of the wavelength-multiplexed optical signal on the path is defined as the maximum wavelength number used.
　非特許文献１の技術によれば、光パスの利用する経路を分散させることにより、各リンクの波長利用率の偏りを低減し、光伝送ネットワーク全体の波長利用率の向上を図ることができる。
　しかし、候補経路数により、以下のような問題が生じることがある。 According to the technique disclosed in Non-Patent Document 1, by dispersing the routes used by optical paths, it is possible to reduce the bias in the wavelength utilization rate of each link and improve the wavelength utilization rate of the entire optical transmission network.
However, depending on the number of candidate routes, the following problems may occur.
　図１は、光伝送ネットワークの一例において、候補経路数Kと光パス設計により選択した最大使用波長番号（実線）の関係及び候補経路数Kと光パス設計の１パスあたりの実行時間（破線）の関係を示す図である。図１に示すように、候補経路数Kを２とした場合には、光パス設計の効果が十分に発揮されておらず、候補経路数Kを２０とした場合には、光パス設計の１パスあたりの実行時間が長くなる問題が発生する。 Figure 1 shows the relationship between the number of candidate routes K and the maximum usage wavelength number selected by optical path design (solid line), and the relationship between the number of candidate routes K and the execution time per path of optical path design (dashed line) in an example of an optical transmission network. FIG. As shown in Figure 1, when the number K of candidate routes is 2, the effect of the optical path design is not fully demonstrated, and when the number K of candidate routes is 20, the effect of the optical path design is not fully demonstrated. A problem occurs where the execution time per pass becomes long.
　図１の例では、光パス設計の実行時間に対して、最大使用波長番号を最適化するためには、候補経路数を５またはそれに近い値に設定して、光パス設計をすることが望ましい。 In the example in Figure 1, in order to optimize the maximum usage wavelength number with respect to the execution time of optical path design, it is desirable to design the optical path by setting the number of candidate routes to 5 or a value close to it. .
　本発明は、複数の候補経路を使用する光パス設計方式により経路探索する際に、光パス設計の効果の最大化と実行時間の短縮を可能にする経路探索装置を提供することを目的とする。 SUMMARY OF THE INVENTION An object of the present invention is to provide a route search device that can maximize the effect of light path design and shorten execution time when searching for a route using an optical path design method that uses a plurality of candidate routes. .
　前記課題を解決するため、本発明の光伝送ネットワークの光パスの経路探索装置は、光伝送ネットワークのトポロジパラメータＤＢの情報に基づいて経路探索を行う候補経路数を導出する最適候補経路数導出部と、前記最適候補経路数導出部で導出した候補経路数分の候補経路を求め、求めた前記候補経路のうち波長多重分割における最大使用波長番号の最も小さい経路を利用経路とし、その最大使用波長番号を、設定する光パスに割り当てる光パス設計部と、を備えるようにした。 In order to solve the above problems, the optical path route search device for an optical transmission network of the present invention includes an optimal candidate route number derivation unit that derives the number of candidate routes for route searching based on information in a topology parameter DB of the optical transmission network. Then, candidate routes for the number of candidate routes derived by the optimal candidate route number derivation section are obtained, and among the candidate routes obtained, the route with the smallest maximum usage wavelength number in wavelength division multiplexing is set as the usage route, and the maximum usage wavelength is set as the usage route. The optical path design unit assigns a number to an optical path to be set.
　本発明によれば、経路探索装置おいて、複数の候補経路を使用する光パス設計方式により経路探索する際に、光パス設計の効果の最大化と実行時間の短縮が可能となる。 According to the present invention, when a route search device performs a route search using an optical path design method using a plurality of candidate routes, it is possible to maximize the effect of optical path design and shorten the execution time.
候補経路数と光パス設計により選択した最大使用波長番号の関係及び候補経路数と光パス設計の実行時間の関係を示す図である。FIG. 7 is a diagram showing the relationship between the number of candidate routes and the maximum usage wavelength number selected by optical path design, and the relationship between the number of candidate routes and the execution time of optical path design. 実施形態の経路探索装置の構成を示す図である。FIG. 1 is a diagram showing the configuration of a route search device according to an embodiment. 実施形態の経路探索装置の機能を実現するコンピュータの一例を示すハードウェア構成図である。FIG. 2 is a hardware configuration diagram showing an example of a computer that implements the functions of the route search device according to the embodiment. 実施形態の経路探索装置の動作を説明するフロー図である。It is a flow diagram explaining operation of a route search device of an embodiment. 光パスの経路探索を行う光伝送ネットワークの一例を示す図である。1 is a diagram illustrating an example of an optical transmission network that performs route search for optical paths; FIG. トポロジ情報ＤＢの構成の一例を示す図である。It is a diagram showing an example of the configuration of a topology information DB. トポロジパラメータＤＢの構成を説明する図である。FIG. 2 is a diagram illustrating the configuration of a topology parameter DB. 光パスの設定を行う際の光伝送ネットワークの状態を示す図である。FIG. 2 is a diagram showing the state of an optical transmission network when setting up an optical path. １つ目の候補経路を示す図である。FIG. 3 is a diagram showing a first candidate route. ２つ目の候補経路を示す図である。It is a figure which shows the second candidate route. ３つ目の候補経路を示す図である。It is a figure which shows the third candidate route.
　以下、実施形態の経路探索における最適候補経路数導出方法及び経路探索装置について、図面を参照しながら詳細に説明する。
　図２は、光伝送ネットワーク７における光パスの経路と波長の割当てを決定する実施形態の経路探索装置１の構成を示す図である。 Hereinafter, a method for deriving the number of optimal candidate routes in route searching and a route searching device according to an embodiment will be described in detail with reference to the drawings.
FIG. 2 is a diagram showing the configuration of a route search device 1 according to an embodiment that determines optical path routes and wavelength assignments in the optical transmission network 7. As shown in FIG.
　詳しくは、光伝送ネットワーク７は、光信号による通信を実現するＩＰ通信ネットワーク等の基幹ネットワークであり、波長多重分割した光信号を伝送する光ファイバによりノード間を接続し（以下、リンクと呼ぶ）、一つ以上のノードを経由して設定されている光パスにより、光パスネットワークを構成している。 Specifically, the optical transmission network 7 is a backbone network such as an IP communication network that realizes communication using optical signals, and connects nodes using optical fibers that transmit wavelength-multiplexed optical signals (hereinafter referred to as links). , an optical path network is configured by optical paths that are set up via one or more nodes.
　実施形態の経路探索装置１は、非特許文献１に記載の技術により最適な光パスの経路と波長の割当てを決定する光パス設計部３と、光パス設計部３が候補経路数を導出する最適候補経路数導出部２と、を有し、不図示のノード制御装置によりノードを制御して、光伝送ネットワーク７の光パスを設定する。
　最適候補経路数導出部２は、詳細を後述するトポロジパラメータ導出部２１と、候補経路数算出部２２とから成る。 The route search device 1 of the embodiment includes an optical path design unit 3 that determines the optimal optical path route and wavelength assignment using the technology described in Non-Patent Document 1, and an optical path design unit 3 that derives the number of candidate routes. The optimum candidate route number deriving unit 2 controls the nodes by a node control device (not shown) to set optical paths of the optical transmission network 7.
The optimal candidate route number deriving unit 2 includes a topology parameter deriving unit 21, which will be described in detail later, and a candidate route number calculating unit 22.
　また、実施形態の経路探索装置１は、光伝送ネットワークにおけるノードとリンクの接続関係を示す情報やノード間の距離を含むトポロジ情報を記憶するトポロジ情報ＤＢ４１と、トポロジパラメータ導出部２１で導出された最適候補経路数の導出に用いるパラメータを格納するトポロジパラメータＤＢ４２と、を含む記憶部４を有する。トポロジ情報ＤＢ４１とトポロジパラメータＤＢ４２の構成は、後述する。 The route search device 1 of the embodiment also includes a topology information DB 41 that stores topology information including information indicating connection relationships between nodes and links in an optical transmission network and distances between nodes, and The storage unit 4 includes a topology parameter DB 42 that stores parameters used for deriving the number of optimal candidate routes. The configurations of the topology information DB 41 and topology parameter DB 42 will be described later.
　さらに、実施形態の経路探索装置１は、光パス設計に使用するトポロジ情報を入力する入力部５と、各種機能の実行結果等を出力する出力部６と、を有する。 Further, the route search device 1 of the embodiment includes an input unit 5 that inputs topology information used for optical path design, and an output unit 6 that outputs execution results of various functions.
　具体的には、実施形態の経路探索装置１は、例えば図３に示すような構成のコンピュータ３００によって実現される。
　図３は、実施形態の経路探索装置１の機能を実現するコンピュータ３００の一例を示すハードウェア構成図である。コンピュータ３００は、ＣＰＵ（Central Processing Unit）３０１、ＲＯＭ（Read Only Memory）３０２、ＲＡＭ３０３、ＨＤＤ（Hard Disk Drive）３０４、入出力Ｉ／Ｆ（Interface）３０５、通信Ｉ／Ｆ３０６及びメディアＩ／Ｆ３０７を有する。 Specifically, the route search device 1 of the embodiment is realized by a computer 300 having a configuration as shown in FIG. 3, for example.
FIG. 3 is a hardware configuration diagram showing an example of a computer 300 that implements the functions of the route search device 1 of the embodiment. The computer 300 includes a CPU (Central Processing Unit) 301, a ROM (Read Only Memory) 302, a RAM 303, an HDD (Hard Disk Drive) 304, an input/output I/F (Interface) 305, a communication I/F 306, and a media I/F 307. have
　ＣＰＵ３０１は、ＲＯＭ３０２またはＨＤＤ３０４に記憶されたプログラムに基づき作動し、制御部による制御を行う。ＲＯＭ３０２は、コンピュータ３００の起動時にＣＰＵ３０１により実行されるブートプログラムや、コンピュータ３００のハードウェアに係るプログラム等を記憶する。 The CPU 301 operates based on a program stored in the ROM 302 or HDD 304, and performs control by the control unit. The ROM 302 stores a boot program executed by the CPU 301 when the computer 300 is started, programs related to the hardware of the computer 300, and the like.
　ＣＰＵ３０１は、入出力Ｉ／Ｆ３０５を介して、マウスやキーボード等の入力装置３１０、及び、ディスプレイやプリンタ等の出力装置３１１を制御する。ＣＰＵ３０１は、入出力Ｉ／Ｆ３０５を介して、入力装置３１０からデータを取得するともに、生成したデータを出力装置３１１へ出力する。なお、プロセッサとしてＣＰＵ３０１とともに、ＧＰＵ（Graphics Processing Unit）等を用いてもよい。 The CPU 301 controls an input device 310 such as a mouse or a keyboard, and an output device 311 such as a display or printer via an input/output I/F 305. The CPU 301 acquires data from the input device 310 via the input/output I/F 305 and outputs the generated data to the output device 311. Note that a GPU (Graphics Processing Unit) or the like may be used in addition to the CPU 301 as the processor.
　ＨＤＤ３０４は、ＣＰＵ３０１により実行されるプログラム及び当該プログラムによって使用されるデータ等を記憶する。通信Ｉ／Ｆ３０６は、通信網（例えば、ＮＷ（Network）３２０）を介して他の装置からデータを受信してＣＰＵ３０１へ出力し、また、ＣＰＵ３０１が生成したデータを、通信網を介して他の装置へ送信する。 The HDD 304 stores programs executed by the CPU 301 and data used by the programs. The communication I/F 306 receives data from other devices via a communication network (for example, NW (Network) 320) and outputs it to the CPU 301, and also sends data generated by the CPU 301 to other devices via the communication network. Send to device.
　メディアＩ／Ｆ３０７は、記録媒体３１２に格納されたプログラムまたはデータを読み取り、ＲＡＭ３０３を介してＣＰＵ３０１へ出力する。ＣＰＵ３０１は、目的の処理に係るプログラムを、メディアＩ／Ｆ３０７を介して記録媒体３１２からＲＡＭ３０３上にロードし、ロードしたプログラムを実行する。記録媒体３１２は、ＤＶＤ（Digital Versatile Disc）、ＰＤ（Phase change rewritable Disk）等の光学記録媒体、ＭＯ（Magneto Optical disk）等の光磁気記録媒体、磁気記録媒体、半導体メモリ等である。 The media I/F 307 reads the program or data stored in the recording medium 312 and outputs it to the CPU 301 via the RAM 303. The CPU 301 loads a program related to target processing from the recording medium 312 onto the RAM 303 via the media I/F 307, and executes the loaded program. The recording medium 312 is an optical recording medium such as a DVD (Digital Versatile Disc) or a PD (Phase change rewritable disk), a magneto-optical recording medium such as an MO (Magneto Optical disk), a magnetic recording medium, a semiconductor memory, or the like.
　例えば、コンピュータ３００等が実施形態の経路探索装置１として機能する場合、コンピュータ３００のＣＰＵ３０１は、ＲＡＭ３０３上にロードされたプログラムを実行することにより、経路探索装置１の最適候補経路数導出部２と光パス設計部３の機能を実現する。また、ＨＤＤ３０４は、トポロジ情報ＤＢ４１とトポロジパラメータＤＢ４２を記憶する記憶部４として機能するとともに、ＨＤＤ３０４には、ＲＡＭ３０３内のデータが記憶される。 For example, when the computer 300 or the like functions as the route searching device 1 of the embodiment, the CPU 301 of the computer 300 executes the program loaded on the RAM 303 to connect the optimal candidate route number deriving unit 2 of the route searching device 1. The functions of the optical path design section 3 are realized. Further, the HDD 304 functions as a storage unit 4 that stores a topology information DB 41 and a topology parameter DB 42, and also stores data in the RAM 303.
　ＣＰＵ３０１は、目的の処理に係るプログラムを記録媒体３１２から読み取って実行する。この他、ＣＰＵ３０１は、他の装置から通信網（ＮＷ３２０）を介して目的の処理に係るプログラムを読み込んでもよい。 The CPU 301 reads a program related to the target process from the recording medium 312 and executes it. In addition, the CPU 301 may read a program related to target processing from another device via a communication network (NW 320).
　次に、実施形態の経路探索装置１の動作を、図４のフロー図により説明する。
　ステップＳ４１で、最適候補経路数導出部２のトポロジパラメータ導出部２１（図２参照）が、トポロジ情報ＤＢ４１に記憶されている情報を基に、候補経路数の決定に必要なパラメータを導出し、トポロジパラメータＤＢ４２に格納する。 Next, the operation of the route searching device 1 according to the embodiment will be explained with reference to the flowchart of FIG. 4.
In step S41, the topology parameter derivation unit 21 (see FIG. 2) of the optimal candidate route number derivation unit 2 derives parameters necessary for determining the number of candidate routes based on the information stored in the topology information DB 41, It is stored in the topology parameter DB 42.
　ステップＳ４２で、候補経路数算出部２２が、トポロジパラメータＤＢ４２を基に、詳細を後述する導出方法により、光パス設計部３が評価対象とする候補経路数の最適値を導出する。 In step S42, the candidate route number calculation unit 22 derives an optimal value for the number of candidate routes to be evaluated by the optical path design unit 3, based on the topology parameter DB 42, using a derivation method that will be described in detail later.
　ステップＳ４３で、光パス設計部３は、ステップＳ４２で候補経路数算出部２２が算出した候補経路数分の候補経路を求め、非特許文献１の技術のように、光伝送ネットワーク７の複数のリンクにまたがる波長の連続性等を考慮し、光伝送ネットワーク全体の波長利用率が向上する光パスの経路と波長を決定する。詳細は後述する。 In step S43, the optical path design unit 3 obtains candidate routes equal to the number of candidate routes calculated by the candidate route number calculation unit 22 in step S42, and as in the technique of Non-Patent Document 1, Optical path routes and wavelengths that improve the wavelength utilization of the entire optical transmission network are determined by considering the continuity of wavelengths across links. Details will be described later.
　ステップＳ４４で、経路探索装置１は、光パス設計部３で決定した光パスの経路と波長の割当てに基づいて、ノード制御装置（不図示）を制御して、光伝送ネットワーク７の光パスを設定する。 In step S44, the route search device 1 controls a node control device (not shown) to create an optical path in the optical transmission network 7 based on the optical path route and wavelength assignment determined by the optical path design unit 3. Set.
　以下に、最適候補経路数導出部２（候補経路数算出部２２）の機能をより詳細に説明する。
　まず、最適候補経路数導出部２が参照するトポロジ情報ＤＢ４１とトポロジパラメータＤＢ４２の構成を説明する。 Below, the functions of the optimal candidate route number deriving unit 2 (candidate route number calculating unit 22) will be explained in more detail.
First, the configurations of the topology information DB 41 and topology parameter DB 42 referred to by the optimal candidate route number deriving unit 2 will be explained.
　図５は、経路探索装置１が光パスの経路探索を行う光伝送ネットワーク７の一例を示す図である。 FIG. 5 is a diagram showing an example of an optical transmission network 7 in which the route search device 1 searches for an optical path.
　図５の黒丸は、配置された局（以下、ノードと呼ぶことがある）を示し、黒丸に添えられて数字は、局を示すノード番号を示している。また、図５の実線は、局と局との間の光ファイバによる伝送路（以下、リンクと呼ぶことがある）を示している。光伝送ネットワーク７は、複数のノード間をリンクにより接続して構成する。 The black circles in FIG. 5 indicate arranged stations (hereinafter sometimes referred to as nodes), and the numbers attached to the black circles indicate node numbers indicating the stations. Further, the solid line in FIG. 5 indicates a transmission path (hereinafter sometimes referred to as a link) using an optical fiber between stations. The optical transmission network 7 is configured by connecting a plurality of nodes with links.
　経路探索装置１（光パス設計部３）は、光伝送ネットワーク７の複数のリンクにまたがる波長の連続性、光伝送の劣化要因がもたらす制約条件、光パスの高信頼化のための冗長化などを考慮し、ノード間のトラヒック需要に応じて光パスを設計して光パスネットワークを構築する。 The route search device 1 (optical path design unit 3) determines the continuity of wavelengths across multiple links of the optical transmission network 7, constraints brought about by optical transmission deterioration factors, redundancy for high reliability of optical paths, etc. Considering this, we design optical paths according to the traffic demand between nodes and construct an optical path network.
　図６は、図５に示した光伝送ネットワーク７のノードやリンク等の接続関係を示す情報を保持するトポロジ情報ＤＢ４１の構成の一例を示す図である。 FIG. 6 is a diagram showing an example of the configuration of the topology information DB 41 that holds information indicating connection relationships of nodes, links, etc. of the optical transmission network 7 shown in FIG. 5.
　トポロジ情報ＤＢ４１は、光伝送ネットワーク７のリンク毎の始点ノードのノード番号を示すノードＡ番号４１１、終点ノードのノード番号を示すノードＺ番号４１２、リンクの距離４１３、リンクを識別するリンク番号４１４とから構成する。 The topology information DB 41 includes a node A number 411 indicating the node number of the starting point node for each link of the optical transmission network 7, a node Z number 412 indicating the node number of the ending node, a link distance 413, and a link number 414 for identifying the link. Consists of.
　図７は、最適候補経路数導出部２のトポロジパラメータ導出部２１が、トポロジ情報ＤＢ４１の情報を基に、候補経路数の決定に必要なパラメータとして導出したトポロジパラメータＤＢ４２の構成を説明する図である。なお、トポロジパラメータは、光伝送ネットワーク７をグラフ理論に基づいてパラメータを定義している。 FIG. 7 is a diagram illustrating the configuration of the topology parameter DB 42 derived by the topology parameter derivation unit 21 of the optimal candidate route number derivation unit 2 as parameters necessary for determining the number of candidate routes based on the information in the topology information DB 41. be. Note that the topology parameters define parameters for the optical transmission network 7 based on graph theory.
　詳しくは、ノード数４２１は、図５に示した光伝送ネットワーク７のノードの数を示す。なお、ノードは、グラフ理論における点とする。
　リンク数４２２は、図５に示した光伝送ネットワーク７のリンクの数を示す。
　平均次数４２３は、光伝送ネットワーク７のあるノードに接続しているリンク数に対応する次数（グラフの頂点に接合する辺の数）の平均値を示す。 Specifically, the number of nodes 421 indicates the number of nodes in the optical transmission network 7 shown in FIG. Note that nodes are points in graph theory.
The number of links 422 indicates the number of links in the optical transmission network 7 shown in FIG.
The average degree 423 indicates the average value of degrees (number of edges connected to vertices of the graph) corresponding to the number of links connected to a certain node of the optical transmission network 7.
　連結度４２４は、連結グラフである光伝送ネットワーク７を非連結にするために取り除く必要のあるノードの数を示す。
　平均連結度４２５は、連結度４２４の平均値を示す。
　辺連結度４２６は、連結グラフである光伝送ネットワーク７を非連結にするために取り除く必要のあるリンクの数を示す。 The degree of connectivity 424 indicates the number of nodes that need to be removed in order to disconnect the optical transmission network 7, which is a connected graph.
The average connectivity degree 425 indicates the average value of the connectivity degrees 424.
The edge connectivity 426 indicates the number of links that need to be removed in order to disconnect the optical transmission network 7, which is a connected graph.
　媒介中心性（平均）４２７は、あるノードＡに対し、それ以外の２ノード間を結ぶ最短経路のうち、あるノードＡを通過する割合である媒介中心性の値の平均値である。
　媒介中心性（最大）４２８は、あるノードＡに対し、それ以外の２ノード間を結ぶ最短経路のうち、あるノードＡを通過する割合である媒介中心性の値の最大値である。 Betweenness centrality (average) 427 is the average value of betweenness centrality values, which is the ratio of the shortest paths connecting a certain node A and two other nodes that pass through a certain node A.
Betweenness centrality (maximum) 428 is the maximum value of betweenness centrality, which is the ratio of the shortest paths connecting a certain node A and two other nodes that pass through a certain node A.
　次に、最適候補経路数導出部２の候補経路数算出部２２の処理を説明する。
　候補経路数算出部２２は、トポロジパラメータＤＢ４２を参照して、次のいずれかの計算式により、光パス設計部３が候補経路数を導出する。 Next, the processing of the candidate route number calculation unit 22 of the optimal candidate route number derivation unit 2 will be explained.
The candidate route number calculation unit 22 refers to the topology parameter DB 42, and the optical path design unit 3 derives the number of candidate routes using one of the following calculation formulas.
　　候補経路数 ＝ リンク数 ／ 平均次数　　　　　　　　　　　　・・・ (1)
　　候補経路数 ＝ リンク数 × 媒介中心性（最大）　　　　　　　・・・ (2)
　　候補経路数 ＝ リンク数 × 平均次数 × 媒介中心性（平均）　・・・ (3) Number of candidate routes = number of links / average degree ... (1)
Number of candidate routes = number of links × betweenness centrality (maximum) ... (2)
Number of candidate routes = number of links × average degree × betweenness centrality (average) ... (3)
　また、候補経路数算出部２２は、(1)式から(3)式によりそれぞれ候補経路数を算出し、算出した候補経路数の最小の値を、候補経路数算出部２２が算出した候補経路数としてもよい。 Further, the candidate route number calculation unit 22 calculates the number of candidate routes using each of equations (1) to (3), and calculates the minimum value of the calculated number of candidate routes to the candidate route calculated by the number of candidate route calculation unit 22. It may be a number.
　ここで、候補経路数算出部２２の具体的な算出例を説明する。
　候補経路数算出部２２は、トポロジパラメータＤＢ４２を参照して、 (1)式により候補経路数を算出する。 Here, a specific example of calculation by the candidate route number calculation unit 22 will be explained.
The candidate route number calculation unit 22 refers to the topology parameter DB 42 and calculates the number of candidate routes using equation (1).
　具体的には、トポロジパラメータＤＢ４２より，リンク数＝17，平均次数=2.83を読取り、 (1)式により6.01に算出されるので、候補経路数は６となる。 Specifically, the number of links = 17 and the average degree = 2.83 are read from the topology parameter DB 42 and calculated as 6.01 using equation (1), so the number of candidate routes is 6.
　光パス設計部３は、候補経路数算出部２２が上記のようにして求めた候補経路数分の始点ノードから終点ノードへの経路を求め、光伝送ネットワーク７の複数のリンクにまたがる波長の連続性、光伝送の劣化要因がもたらす制約条件、光パスの高信頼化のための冗長化などを考慮し、ノード間のトラヒック需要に応じて最適な光パスを決定する。 The optical path design unit 3 calculates routes from the start node to the destination node for the number of candidate routes calculated as described above by the candidate route number calculation unit 22, and calculates the routes from the start node to the end node as many as the number of candidate routes calculated by the candidate route number calculation unit 22 as described above. The optimal optical path is determined according to the traffic demand between nodes, taking into account factors such as performance, constraints brought about by optical transmission deterioration factors, and redundancy to increase the reliability of the optical path.
　次に、光パス設計部３の光パスの決定方式を図８、図９Ａ、図９Ｂ、図９Ｃにより説明する。 Next, the optical path determination method of the optical path design unit 3 will be explained with reference to FIGS. 8, 9A, 9B, and 9C.
　図８は、光パスの設定を行う際の光伝送ネットワークの状態を示す図である。ノードＳは、光パスの始点ノードであり、ノードＤは、光パスの終点ノードである。また、それぞれのリンクは、６波長の波長多重分割した光信号を伝送する光ファイバであり、それぞれのリンクの波長番号の使用波長と未使用波長を示している。 FIG. 8 is a diagram showing the state of the optical transmission network when setting an optical path. The node S is the starting point node of the optical path, and the node D is the ending point node of the optical path. Furthermore, each link is an optical fiber that transmits an optical signal that has been wavelength-multiplexed and divided into six wavelengths, and the used wavelength and unused wavelength of the wavelength number of each link are shown.
　図示していないが、図８の光伝送ネットワークには既にリンクの使用波長を使用した複数の光パスが設定されており、光パス設計部３は、ノードＳからノードＤへの光パスを追加（設定）する。 Although not shown, a plurality of optical paths using the wavelengths used by the links have already been set up in the optical transmission network of FIG. 8, and the optical path design unit 3 adds an optical path from node S to node D. (set).
　候補経路数算出部２２が、図８の光伝送ネットワークの状態に基づいて、候補経路数を３に導出したとすると、光パス設計部３は、図９Ａ、図９Ｂ、図９Ｃの３つの候補経路を求める。光パス設計部３は、例えば、K-Shortest Path アルゴリズムにより、最短経路順に３つの候補経路を求める。 If the candidate route number calculation unit 22 derives the number of candidate routes to three based on the state of the optical transmission network in FIG. 8, the optical path design unit 3 calculates the three candidates shown in FIGS. 9A, 9B, and 9C Find a route. The optical path design unit 3 uses, for example, the K-Shortest Path algorithm to find three candidate paths in order of the shortest path.
　光パス設計部３は、図９Ａの候補経路ａにおいて、波長の連続性、光伝送の劣化要因がもたらす制約条件を考慮して、使用する波長として、波長番号６の波長を選択し、光パスaを求める。 The optical path design unit 3 selects the wavelength of wavelength number 6 as the wavelength to be used in the candidate route a of FIG. Find a.
　また、光パス設計部３は、図９Ｂの候補経路ｂにおいては、波長番号５、波長番号６の波長を選択でき、候補経路ｂで波長番号５の光パスｂ１と、候補経路ｂで波長番号６の光パスｂ２を求める。 Further, the optical path design unit 3 can select wavelengths with wavelength numbers 5 and 6 in candidate route b in FIG. 9B, and can select wavelengths with wavelength numbers 5 and 6 in candidate route b and Find the optical path b2 of No. 6.
　さらに、光パス設計部３は、図９Ｃの候補経路ｃにおいては、波長番号３、波長番号４の波長を選択でき、候補経路ｃで波長番号３の光パスｃ１と、候補経路ｃで波長番号４の光パスｃ２を求める。なお、図９Ｃでは、波長番号５、６も使用可能であるが、ここでは、波長番号３、４を使用することにする。 Furthermore, the optical path design unit 3 can select wavelengths with wavelength numbers 3 and 4 in the candidate route c in FIG. 9C, and select the optical path c1 with the wavelength number 3 in the candidate route c, and Find the optical path c2 of 4. In addition, in FIG. 9C, although wavelength numbers 5 and 6 can also be used, wavelength numbers 3 and 4 will be used here.
　そして、光パス設計部３は、図９Ａ、図９Ｂ、図９Ｃの３つの候補経路ａ、ｂ、ｃにおいて、経路における波長多重分割した光信号の波長に対応する波長番号の最大である最大使用波長番号が最も小さい図９Ｃの候補経路ｃを利用経路とし、波長番号が３の波長を追加する光パスに割り当てる。 Then, the optical path design unit 3 determines the maximum usage of the wavelength number corresponding to the wavelength of the wavelength-multiplexed optical signal in the three candidate routes a, b, and c in FIGS. 9A, 9B, and 9C. The candidate route c in FIG. 9C with the smallest wavelength number is set as the route to be used, and the wavelength with wavelength number 3 is assigned to the optical path to be added.
　光パス設計部３は、上記のように、最適候補経路数導出部２で導出した候補経路数分の候補経路を求め、求めた候補経路のうち波長多重分割における最大使用波長番号の最も小さい経路を利用経路とし、その最大使用波長番号を設定する光パスに割り当てる。これにより、利用波長の偏りを低減し、光パスの収容数を増加することができるので、光伝送ネットワーク全体の波長利用率の向上を図ることができる。 As described above, the optical path design unit 3 determines candidate routes for the number of candidate routes derived by the optimal candidate route number derivation unit 2, and selects the route with the smallest maximum used wavelength number in wavelength division multiplexing among the determined candidate routes. is used as the route to be used, and its maximum used wavelength number is assigned to the optical path to be set. As a result, it is possible to reduce the bias in the wavelengths used and increase the number of optical paths that can be accommodated, so it is possible to improve the wavelength utilization rate of the entire optical transmission network.
＜効果＞
　以下、本発明に係る経路探索装置の効果について説明する。
　本発明に係る経路探索装置１は、光伝送ネットワークの光パスの経路探索装置１であって、光伝送ネットワークのトポロジパラメータＤＢ４２の情報に基づいて経路探索を行う候補経路数を導出する最適候補経路数導出部２と、最適候補経路数導出部２で導出した候補経路数分の候補経路を求め、求めた候補経路のうち波長多重分割における最大使用波長番号の最も小さい経路を利用経路とし、その最大使用波長番号を、設定する光パスに割り当てる光パス設計部３と、を備えることを特徴とする。 <Effect>
Hereinafter, the effects of the route search device according to the present invention will be explained.
The route search device 1 according to the present invention is a route search device 1 for optical paths in an optical transmission network, and is an optimal candidate route for deriving the number of candidate routes for route searching based on information in the topology parameter DB 42 of the optical transmission network. The number deriving unit 2 and the optimal candidate route number deriving unit 2 calculate candidate routes for the number of candidate routes derived, and among the candidate routes found, the route with the smallest maximum used wavelength number in wavelength division multiplexing is set as the usage route, and The present invention is characterized by comprising an optical path design unit 3 that assigns a maximum usage wavelength number to an optical path to be set.
　これにより、経路探索する候補経路を最適化できるので、光パス設計の効果の最大化と実行時間の短縮が可能となる。 This makes it possible to optimize the candidate routes for route searching, making it possible to maximize the effect of optical path design and shorten execution time.
　詳しくは、最適候補経路数導出部２は、トポロジパラメータＤＢ４２のリンク数４２２と平均次数４２３とに基づいて、リンク数４２２を平均次数４２３で除して候補経路数を算出する。
　また、最適候補経路数導出部２は、トポロジパラメータＤＢ４２のリンク数４２２と媒介中心性の最大４２８の値とに基づいて、リンク数４２２に媒介中心性の最大４２８の値を乗じて候補経路数を算出する。
　また、最適候補経路数導出部２は、トポロジパラメータＤＢ４２のリンク数４２２と平均次数４２３と媒介中心性の平均４２７の値とに基づいて、リンク数４２２と平均次数４２３と媒介中心性の平均４２７の値とを乗じて候補経路数を算出する。 Specifically, the optimal number of candidate routes deriving unit 2 calculates the number of candidate routes by dividing the number of links 422 by the average degree 423 based on the number of links 422 and the average degree 423 of the topology parameter DB 42.
Further, the optimum number of candidate routes deriving unit 2 calculates the number of candidate routes by multiplying the number of links 422 by the maximum value of betweenness centrality of 428, based on the number of links 422 of the topology parameter DB 42 and the maximum value of betweenness centrality of 428. Calculate.
Further, the optimal candidate route number deriving unit 2 calculates the number of links 422, the average degree 423, and the average betweenness centrality 427 based on the values of the number of links 422, the average degree 423, and the average betweenness centrality 427 of the topology parameter DB 42. The number of candidate routes is calculated by multiplying by the value of .
　これにより、最適候補経路数導出部２は、簡易に候補経路数を算出できるので、候補経路数導出に使用する計算リソースの削減が可能となる。 As a result, the optimum number of candidate routes deriving unit 2 can easily calculate the number of candidate routes, so it is possible to reduce the calculation resources used for deriving the number of candidate routes.
　なお、本発明は、以上説明した実施形態に限定されるものではなく、多くの変形が本発明の技術的思想内で当分野において通常の知識を有する者により可能である。 Note that the present invention is not limited to the embodiments described above, and many modifications can be made within the technical idea of the present invention by those having ordinary knowledge in this field.
　１　経路探索装置
　２　最適候補経路数導出部
　２１　トポロジパラメータ導出部
　２２　候補経路数算出部
　３　光パス設計部
　４　記憶部
　４１　トポロジ情報ＤＢ
　４２　トポロジパラメータＤＢ
　５　入力部
　６　出力部
　７　光伝送ネットワーク 1 Route search device 2 Optimal candidate route number derivation unit 21 Topology parameter derivation unit 22 Candidate route number calculation unit 3 Optical path design unit 4 Storage unit 41 Topology information DB
42 Topology parameter DB
5 Input section 6 Output section 7 Optical transmission network

Claims (7)

  1. 　光伝送ネットワークの光パスの経路探索装置であって、
    　光伝送ネットワークのトポロジパラメータＤＢの情報に基づいて経路探索を行う候補経路数を導出する最適候補経路数導出部と、
    　前記最適候補経路数導出部で導出した候補経路数分の候補経路を求め、求めた前記候補経路のうち波長多重分割における最大使用波長番号の最も小さい経路を利用経路とし、その最大使用波長番号を、設定する光パスに割り当てる光パス設計部と、
    を備えることを特徴とする経路探索装置。     A path search device for an optical path in an optical transmission network,
    an optimal candidate route number derivation unit that derives the number of candidate routes for route searching based on information in a topology parameter DB of the optical transmission network;
    Find candidate routes for the number of candidate routes derived by the optimal candidate route number derivation unit, set the route with the smallest maximum usage wavelength number in wavelength division multiplexing among the candidate routes found as the usage route, and set the maximum usage wavelength number as the usage route. , an optical path design unit that allocates to the optical path to be set;
    A route searching device comprising:
  2. 　請求項１に記載の経路探索装置において、
    　前記最適候補経路数導出部は、前記トポロジパラメータＤＢのリンク数と平均次数とに基づいて、前記リンク数を前記平均次数で除して前記候補経路数を算出する
    ことを特徴とする経路探索装置。     The route search device according to claim 1,
    The optimal candidate route number deriving unit calculates the number of candidate routes by dividing the number of links by the average degree based on the number of links and the average degree of the topology parameter DB. .
  3. 　請求項１に記載の経路探索装置において、
    　前記最適候補経路数導出部は、前記トポロジパラメータＤＢのリンク数と媒介中心性の最大値とに基づいて、前記リンク数に前記媒介中心性の最大値を乗じて前記候補経路数を算出する
    ことを特徴とする経路探索装置。     The route search device according to claim 1,
    The optimal number of candidate routes deriving unit calculates the number of candidate routes by multiplying the number of links by the maximum value of betweenness centrality, based on the number of links in the topology parameter DB and the maximum value of betweenness centrality. A route searching device characterized by:
  4. 　請求項１に記載の経路探索装置において、
    　前記最適候補経路数導出部は、前記トポロジパラメータＤＢのリンク数と平均次数と媒介中心性の平均値とに基づいて、前記リンク数と前記平均次数と前記媒介中心性の平均値とを乗じて前記候補経路数を算出する
    ことを特徴とする経路探索装置。     The route search device according to claim 1,
    The optimal candidate route number deriving unit multiplies the number of links, the average degree, and the average value of betweenness centrality based on the number of links, average degree, and average value of betweenness centrality in the topology parameter DB. A route search device that calculates the number of candidate routes.
  5. 　光伝送ネットワークの光パスの経路探索方法であって、
    　光伝送ネットワークのトポロジパラメータに基づいて経路探索を行う候補経路数を導出するステップと、
    　導出した候補経路数分の候補経路を求めるステップと、
    　求めた前記候補経路のうち波長多重分割における最大使用波長番号の最も小さい経路を利用経路とし、その最大使用波長番号を、設定する光パスに割り当てるステップと、
    を含むことを特徴とする経路探索方法。     A route search method for an optical path in an optical transmission network, the method comprising:
    deriving a number of candidate routes for route searching based on topology parameters of the optical transmission network;
    obtaining candidate routes for the number of derived candidate routes;
    Among the candidate routes obtained, the route with the smallest maximum usage wavelength number in wavelength division multiplexing is set as the usage route, and the maximum usage wavelength number is assigned to the optical path to be set;
    A route searching method characterized by comprising:
  6. 　請求項５に記載の経路探索方法において、
    　候補経路数を導出するステップは、
    　前記トポロジパラメータであるリンク数を前記トポロジパラメータである平均次数で除して候補経路数を算出するステップ、
    　前記トポロジパラメータであるリンク数に前記トポロジパラメータである媒介中心性の最大値を乗じて候補経路数を算出するステップ、または、
    　前記トポロジパラメータであるリンク数と前記トポロジパラメータである平均次数と前記トポロジパラメータである媒介中心性の平均値とを乗じて候補経路数を算出するステップから成る
    ことを特徴とする経路探索方法。     In the route searching method according to claim 5,
    The step of deriving the number of candidate routes is
    calculating the number of candidate routes by dividing the number of links, which is the topology parameter, by the average degree, which is the topology parameter;
    calculating the number of candidate routes by multiplying the number of links, which is the topology parameter, by the maximum value of betweenness centrality, which is the topology parameter, or
    A route search method comprising the step of calculating the number of candidate routes by multiplying the number of links as the topology parameter, the average degree as the topology parameter, and the average value of betweenness centrality as the topology parameter.
  7. 　コンピュータを、請求項１乃至請求項４のいずれか一項に記載の経路探索装置として機能させるためのプログラム。 A program for causing a computer to function as the route searching device according to any one of claims 1 to 4.
PCT/JP2022/024614 2022-06-20 2022-06-20 Route search device, route search method, and program WO2023248316A1 (en)

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Citations (1)

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Publication number Priority date Publication date Assignee Title
JP2018093335A (en) * 2016-12-01 2018-06-14 日本電信電話株式会社 Communication apparatus

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018093335A (en) * 2016-12-01 2018-06-14 日本電信電話株式会社 Communication apparatus

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
HANAMI YOKOI, KOHJUN KOSHIJI, YASUHARU KANEKO, TATSUYA MATSUKAWA, TAKASHI MIYAMURA: "Routing and Wavelength Assignment based on Quality of Transmission and Modulation", IEICE TECHNICAL REPORT, NS, IEICE, JP, vol. 121, no. 262 (NS2021-87), 18 November 2021 (2021-11-18), JP, pages 18 - 23, XP009551658 *

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