WO2018181031A1 - Dispositif de conception de chemin optique et procédé de conception de chemin optique - Google Patents

Dispositif de conception de chemin optique et procédé de conception de chemin optique Download PDF

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Publication number
WO2018181031A1
WO2018181031A1 PCT/JP2018/011806 JP2018011806W WO2018181031A1 WO 2018181031 A1 WO2018181031 A1 WO 2018181031A1 JP 2018011806 W JP2018011806 W JP 2018011806W WO 2018181031 A1 WO2018181031 A1 WO 2018181031A1
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Prior art keywords
optical path
parameter
design
path design
characteristic value
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PCT/JP2018/011806
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English (en)
Japanese (ja)
Inventor
竹下　仁士
慎介 藤澤
田島　章雄
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日本電気株式会社
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Publication of WO2018181031A1 publication Critical patent/WO2018181031A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/27—Arrangements for networking

Definitions

  • the present invention relates to an optical path design apparatus and an optical path design method, and more particularly to an optical path design apparatus and an optical path design method used in an optical communication network using a wavelength division multiplexing system.
  • Wavelength division multiplexing technology is used for the core network.
  • the communication service which connects between points is accommodated in an optical path.
  • the optical path capacity is sufficiently large, a plurality of communication services can be multiplexed and accommodated in one optical path.
  • RSA frequency resource
  • the solution may not be found if network resources are insufficient. This means that the generation of the optical path has failed, and the desired service cannot be provided between desired points.
  • the resources of a wavelength division multiplexing optical network include, for example, the number of nodes, the distance between nodes, the number of optical fibers connecting the nodes, the number of optical transceivers (transponders) deployed in the nodes, the wavelength band occupied by the optical path, and optical transmission.
  • the resources of a wavelength division multiplexing optical network include, for example, the number of nodes, the distance between nodes, the number of optical fibers connecting the nodes, the number of optical transceivers (transponders) deployed in the nodes, the wavelength band occupied by the optical path, and optical transmission.
  • a wavelength division multiplexing network is generally composed of a large number of nodes and links, and a path connecting desired points, that is, an RSA problem solution is often not unique.
  • the Dijkstra method is generally used for finding a solution, that is, searching for an optical path. In the Dijkstra method, even if there are a plurality of solutions, the solution having the shortest path length is selected, so that the solution can be obtained uniquely.
  • Linear programming and heuristic methods are often used to find solutions. In linear programming, a completely optimal solution is required, but the problem is that it takes a very long time to obtain a solution. Depending on the calculation conditions, a solution cannot be obtained in a realistic time, and a solution may not be obtained substantially.
  • the heuristic method takes a relatively short time to obtain a solution, but the obtained solution is not necessarily a completely optimal solution. Even when the heuristic method is used, for example, when the number of nodes is large or the number of optical paths to be handled is large, the time required to obtain a solution becomes long. In general, as network resources such as the number of nodes increase, the calculation time increases exponentially.
  • the design parameter hardly changed with time. This is because the wavelength multiplexing optical communication network is a fixed network.
  • the wavelength division multiplexing optical communication network is a fixed network.
  • the optimization is very complicated because each parameter changes over time in optical path design that requires various design parameters. Along with this, the time required for optimization increases dramatically.
  • the wavelength division multiplexing optical communication network has a problem that the time required for the optical path optimization increases dramatically due to an increase in design parameters and a dynamic change.
  • the object of the present invention is to solve the above-described problem that in the wavelength division multiplexing optical communication network, the time required for optical path optimization increases dramatically due to an increase in design parameters and a dynamic change.
  • An object of the present invention is to provide an optical path design apparatus and an optical path design method.
  • the optical path design apparatus of the present invention relates to an optical path in which a parameter element, which is an element that can be taken by each of a plurality of design parameters of an optical path, and a characteristic value indicating a characteristic of the optical path designed using the parameter element are related to each other.
  • a parameter element which is an element that can be taken by each of a plurality of design parameters of an optical path
  • a characteristic value indicating a characteristic of the optical path designed using the parameter element are related to each other.
  • the optical path design method of the present invention relates to an optical path in which a parameter element, which is an element that can be taken by each of a plurality of design parameters of an optical path, and a characteristic value indicating the characteristic of the optical path designed using the parameter element are related to each other.
  • a parameter element which is an element that can be taken by each of a plurality of design parameters of an optical path
  • a characteristic value indicating the characteristic of the optical path designed using the parameter element are related to each other.
  • optical path design apparatus and the optical path design method of the present invention it is possible to reduce the time required for optical path optimization in a wavelength division multiplexing optical communication network.
  • FIG. 1 is a block diagram showing a configuration of an optical path design apparatus 100 according to the first embodiment of the present invention.
  • the optical path design apparatus 100 includes a design result acquisition unit (design result acquisition unit) 110, a correlation calculation unit (correlation calculation unit) 120, and a redesign parameter determination unit (redesign parameter determination unit) 130.
  • the design result acquisition unit 110 associates a parameter element, which is an element that can be taken by each of a plurality of design parameters of an optical path, with a characteristic value indicating a characteristic of the optical path designed using the parameter element. Get the result.
  • the correlation calculation unit 120 uses the changed parameter element as an index for one design parameter having the changed parameter element in which an additional element not included in the optical path design result is added to the parameter element. The correlation between is calculated.
  • the redesign parameter determination unit 130 estimates the redesign characteristic value, which is the characteristic value for the additional element, from the optical path design result and the correlation, thereby using the parameter elements of other design parameters that give the redesign characteristic value. A certain redesign parameter element is determined.
  • the redesign characteristic value that is the characteristic value for the additional element is estimated from the optical path design result and the correlation.
  • a redesign parameter element that is a parameter element of another design parameter that gives the estimated redesign characteristic value is determined.
  • a parameter element that can be taken by each of a plurality of design parameters of the optical path, and a characteristic value indicating a characteristic of the optical path designed using the parameter element are obtained.
  • the related optical path design results are obtained for one design parameter having a changed parameter element in which an additional element not included in the optical path design result is added to the parameter element.
  • the post-change parameter element is indexed, thereby correlating the changed parameter elements. Is calculated.
  • a redesign parameter element that is a parameter element of another design parameter that gives a redesign characteristic value by estimating a redesign characteristic value that is a characteristic value for the additional element from the optical path design result and correlation described above To decide.
  • This configuration eliminates the need to recalculate the characteristic values for all parameter elements that can be taken by other design parameters in order to optimize the optical path for the additional elements.
  • the optical path design method of the present embodiment it is possible to reduce the time required for optical path optimization in the wavelength division multiplexing optical communication network.
  • FIG. 2 shows a configuration of a wavelength division multiplexing optical communication network system targeted by the optical path design apparatus 100 according to the present embodiment.
  • the statistic Y of the optical path design result changes depending on the optical path design parameters A and B in the wavelength division multiplexing optical communication network 1000 will be described.
  • the optical nodes 1001 to 1005 are connected by optical fibers.
  • the characteristic value Y indicating the characteristic of the optical path changes according to the parameters A and B.
  • the wavelength division multiplexing optical communication network 1000 is managed by a network management system (NMS) 1100.
  • the NMS 1100 is connected to the optical nodes 1001 to 1005, and is configured to give various instructions to the optical nodes 1001 to 1005 and collect information on the optical nodes 1001 to 1005.
  • PCE Principal Computation Element
  • the PCE 1200 is further connected to the analysis function unit 1300.
  • the PCE 1200 performs optical path design in the wavelength division multiplexing optical communication network 1000 using the design parameters ai and bj received from the NMS 1100.
  • the analysis function unit 1300 analyzes the characteristics of the wavelength division multiplexing optical communication network 1000 in which the optical path is designed by the PCE 1200, and digitizes the analysis result.
  • Y F (A, B).
  • the analysis function unit 1300 is further connected to a database (DB) 1400.
  • FIG. 3 shows an example of data stored in the DB 1400.
  • FIG. 3 shows a case where m ⁇ n results obtained by calculating characteristic values y for m parameter elements A and n parameter elements B are stored.
  • the values of parameters A and B are changed, that is, the number of elements of parameter A and parameter B is increased, the number of elements of Y also increases.
  • the number of data stored in the DB 1400 increases as the optical path design is performed with different parameter values for the parameter A and the parameter B.
  • RSA Raster and Spectrum Assignment
  • the calculation time required for optical path design using the RSA algorithm generally increases exponentially according to the number of optical paths to be handled and the scale of the network. Therefore, when an optical path design is performed under conditions close to an actual network, there is a problem that the calculation may not be completed in a realistic time as described above.
  • the analysis function unit 1300 performs a statistical process on the distribution of hi1 (step S1200) to obtain a correlation between the parameter A and hi1. That is, by performing statistical processing on the distribution of hi1, the parameter B is fixed to b1, and the statistical value y1 when the parameter A changes in the range of a1 to am can be obtained (step S1300).
  • FIG. 5 shows an operation for obtaining an optical path design result when the parameter B is changed from b1 to b2.
  • the value taken by the parameter B is changed from b1 to b2, but the operation is the same as that shown in FIG.
  • the obtained statistical value is y2 reflecting that the parameter B has changed from b1 to b2.
  • FIG. 6 summarizes the procedure described with reference to FIGS. 4 and 5.
  • the design parameter A of the wavelength multiplexing optical communication network changes within the range of a1 to am and the parameter B changes within the range of b1 to bn
  • the statistical value Y representing the characteristics of the design result of the wavelength multiplexing optical communication network is , Y1 to yn.
  • bn shown in FIG. 6 is replaced with b (n + 1).
  • y (n + 1) f (A, b (n + 1)) is added to y (n) for calculation.
  • the only parameter element added for the parameter B is b (n + 1), but this affects all of the parameters A having m possible values. Therefore, the number of calculations that need to be additionally performed is m.
  • the results are added and accumulated in the DB 1400 (see FIG. 3), and the DB 1400 is updated.
  • the NMS 1100 can obtain the statistical value y (n + 1) corresponding to b (n + 1) by referring to the DB 1400.
  • a new function g is introduced. By introducing the function g, it is possible to reduce the number m of necessary calculations described above.
  • FIG. 7 shows the relationship between Z, B, and g.
  • FIG. 8A is a graph of the statistical value Y that represents the characteristics of the design result of the wavelength division multiplexing optical communication network described with reference to FIG. 6 when there are three possible values of the design parameter B, b1, b2, and b3. It is a thing.
  • the optical path design apparatus 100 of the present embodiment uses a correlation between the statistical value Y indicating the characteristics of the optical path that has already been obtained and the elements of the design parameter B.
  • the magnitude relationship between the elements of the design parameter B can be used. That is, the correlation calculation unit 120 included in the optical path design device 100 can be configured to calculate a magnitude relationship obtained by quantifying the parameter elements after change as the correlation.
  • the changed parameter element is a parameter element of the design parameter B in which b4 is newly added in the above-described example.
  • the magnitude relationship between the design parameters of the optical path in the wavelength division multiplexing optical communication network is not always determined.
  • the network topology as shown in FIGS. 9A, 9B, and 9C is used as a design parameter.
  • the element b1 of the design parameter B is a 4 ⁇ 4 mesh topology (FIG. 9A)
  • b2 is a 16-node ring topology (FIG. 9B)
  • b3 is a 16-node star topology (FIG. 9C)
  • the magnitude relationship between b1 to b3 is It cannot be quantified simply.
  • the function g is introduced so that the magnitude relationship between b1 and b3 can be defined. Therefore, the function g needs to be selected according to the design parameter B.
  • the design parameter B is the topology described above, the magnitude relationship can be defined using, for example, graph theory.
  • distribution Y4 may exist between distribution Y1 and distribution Y2. I can expect. That is, it can be predicted that the distribution Y4 exists in the shaded area shown in FIG. 8B.
  • the optical path design apparatus 100 of the present embodiment it is not necessary to perform optical path design for all values (parameter elements) that the design parameter A can take. This is because by introducing the function g that determines the magnitude relationship of the design parameter B, the element a4 of the design parameter A corresponding to the statistical value y4 is in the range of a1 ⁇ a4 ⁇ a2, as shown in FIG. 8B. (The range indicated by the arrow (1) in FIG. 8B). Therefore, the number of calculations of the optical path design required for obtaining y4 can be reduced from m times to one.
  • the calculation time required to narrow the range of values that can be taken by the design parameter A using the function g is negligibly short compared to the time required for the optical path design using the RSA algorithm. Therefore, when b4 is added, the time required to update the DB 1400 according to an instruction from the NMS 1100 can be shortened to 1 / m. As a result, the optical path can be optimized even when the design parameters of the network change with time.
  • the optical path design device 100 and the optical path design method of the present embodiment it is possible to shorten the time required for optical path optimization in the wavelength division multiplexing optical communication network. As a result, the optical path can be optimized even when the design parameters of the network change with time.
  • the wavelength multiplexing optical communication network 1000 can adopt a 4 ⁇ 4 square lattice mesh network as a network topology.
  • the topology showing the connection state between the optical node and the optical fiber in this case is as shown in FIG. 9A.
  • the guard band allocation method can be selected as the optical path design parameter A. That is, the design parameters targeted by the optical path design apparatus according to the present embodiment include at least the node order centrality and the guard band allocation method. Specifically, as shown in FIG. 11, when the optical signal band of the same optical modulation system is adjacent to the a1 system that always provides guard bands at both ends of the optical signal band, One of the a2 methods that omits the guard band can be selected. As shown in FIG. 11, when the two optical signal bands are not adjacent, there is no difference between the a1 method and the a2 method.
  • the design result acquisition unit 110 included in the optical path design device 100 can be configured to use the maximum value of the amount of communication traffic that can be accommodated in the optical network as the characteristic value.
  • b1 among parameter elements that can be taken by the design parameter B is a 4 ⁇ 4 mesh network.
  • each optical fiber connecting between optical nodes in a 4 ⁇ 4 mesh network has a capacity capable of accommodating, for example, 200 optical signal bands corresponding to a communication traffic amount of 200 Gbps.
  • the communication traffic request is assumed to be a full mesh traffic that is generated in an equal number for each node, and the generation order is randomly generated.
  • a guard band may be added to the optical signal band accommodating communication traffic.
  • the amount of communication traffic that can be accommodated is always greater in the a2 method with fewer guard bands to be added, but this is not necessarily the case.
  • the combined bandwidth of the optical signal and the guard band is not uniform depending on whether or not the guard band is provided. Therefore, in the case of the a2 method, there is a possibility that the fragmentation of the wavelength band becomes larger than that in the a1 method.
  • the fragmentation of the wavelength band causes a reduction in communication traffic accommodation efficiency. Therefore, it cannot be easily determined which of the a1 method and the a2 method can accommodate more communication traffic.
  • the situation where the wavelength band is fragmented depends on the topology. Therefore, when one optical node is added or when one optical fiber is added, the result of which of the a1 method and the a2 method can accommodate more communication traffic may change.
  • the statistical value Y is defined as the maximum value of the amount of communication traffic that can be accommodated in a wavelength-multiplexed optical communication network of a certain topology. According to this definition, Y indicates how small the amount of traffic that could not be accommodated when the communication traffic request was increased. That is, Y indicates how small the blocking rate of the optical path accommodating communication traffic is in the optical path design using the RSA algorithm.
  • the optical path design apparatus of the present embodiment the statistical value y1 for the parameter element b1 is obtained, and the function value g for determining the magnitude relationship of the parameter element b is determined, thereby obtaining the statistical value y2 for the parameter element b2.
  • the calculation of can be omitted.
  • An example will be described.
  • a case where a function for calculating the degree centrality is employed as the function g will be described. That is, a case will be described in which the correlation calculation unit included in the optical path design apparatus of the present embodiment is configured to index the changed parameter elements (b1 to b3) by digitizing the characteristics of the network topology.
  • the difference between the values of b1 and b2 is small, and the difference between b1 and b3 is extremely large.
  • the possible value of the design parameter A is either a1 or a2.
  • FIG. 15 shows that the prediction according to the present embodiment described above was correct.
  • optical path design apparatus and the optical path design method of the present embodiment it is possible to shorten the time required for optical path optimization in the wavelength division multiplexing optical communication network.
  • the values of m and n are not limited to these, and it is apparent that the effect of the present embodiment can be obtained even when other values are used.
  • the function g for determining the magnitude relationship of the parameter elements.
  • the present invention is not limited to this, and a function that calculates features of other topologies may be adopted as the function g.
  • the topological features using graph theory include degree centrality, intermediary centrality, proximity centrality and their central tendency, Bonachic centrality, eigenvector centrality, Euclidean distance, diameter, density, average distance, Transitivity, ⁇ coefficient, correlation matrix, distance matrix are included.
  • the results of narrowing down the range of the a4 value by the function gi differ, it can be determined by, for example, majority vote.
  • the prediction accuracy increases as the number of p increases.
  • the plurality of functions gi for example, two or more types of functions that respectively calculate two or more of the topological features using the graph theory described above can be employed.
  • the correlation calculation unit 120 included in the optical path design device 100 may be configured to calculate a plurality of correlations between the changed parameter elements by performing a plurality of types of indexing on the changed parameter elements.
  • the redesign parameter determination unit 130 can be configured to determine the redesign parameter element by estimating the redesign characteristic value from the optical path design result and a plurality of correlations.

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  • Engineering & Computer Science (AREA)
  • Computing Systems (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Computer Networks & Wireless Communication (AREA)
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Abstract

La présente invention aborde le problème d'une forte augmentation du temps requis pour une optimisation de chemin optique en raison d'augmentations de paramètres de conception et de changements dynamiques dans un réseau de communication optique à multiplexage de longueurs d'onde. Un dispositif de conception de chemin optique selon la présente invention comprend : un moyen d'acquisition de résultat de conception qui acquiert un résultat de conception de chemin optique dans lequel un facteur paramétrique, qui est un facteur que chaque paramètre d'une pluralité de paramètres de conception pour un chemin optique pourrait prendre, et une valeur de caractéristique, qui indique une caractéristique d'un chemin optique conçu à l'aide du facteur paramétrique, sont associés l'un avec l'autre ; un moyen de calcul de corrélation qui, en ce qui concerne un paramètre de conception incluant un facteur paramétrique modifié obtenu par addition d'un facteur additionnel au facteur paramétrique qui n'est pas inclus dans le résultat de conception de chemin optique, calcule une corrélation entre des facteurs paramétriques modifiés à l'aide du facteur paramétrique modifié en tant qu'indice ; et un moyen de détermination de paramètre de reconception qui, par estimation à partir du résultat de conception de chemin optique et de la corrélation d'une valeur de caractéristique de reconception qui est une valeur de caractéristique en ce qui concerne le facteur additionnel, détermine un facteur paramétrique de reconception qui est facteur paramétrique d'un autre paramètre de conception fournissant la valeur de caractéristique de reconception.
PCT/JP2018/011806 2017-03-31 2018-03-23 Dispositif de conception de chemin optique et procédé de conception de chemin optique WO2018181031A1 (fr)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017013708A1 (fr) * 2015-07-17 2017-01-26 三菱電機株式会社 Dispositif de gestion de réseau et programme de gestion de réseau
WO2017138550A1 (fr) * 2016-02-12 2017-08-17 日本電気株式会社 Dispositif de commande de réseau optique et procédé de réglage de chemin optique
JP2017216507A (ja) * 2016-05-30 2017-12-07 富士通株式会社 制御装置、制御方法、及び、制御プログラム

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017013708A1 (fr) * 2015-07-17 2017-01-26 三菱電機株式会社 Dispositif de gestion de réseau et programme de gestion de réseau
WO2017138550A1 (fr) * 2016-02-12 2017-08-17 日本電気株式会社 Dispositif de commande de réseau optique et procédé de réglage de chemin optique
JP2017216507A (ja) * 2016-05-30 2017-12-07 富士通株式会社 制御装置、制御方法、及び、制御プログラム

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DING, HUI ET AL.: "Dynamic routing and frequency slot allocation in Elastic optical path network using adaptive modulations with consideration of both spectrum availability and distance", ASIA COMMUNICATIONS AND PHOTONICS CONFERENCE AND EXHIBITION, 13 November 2011 (2011-11-13), pages 1 - 6, XP060000284, DOI: doi:10.1117/12.904215 *
FENG, GANG ET AL.: "A heuristic for routing, modulation and spectrum allocation in spectrum sliced elastic optical path network", 2015 IEEE INTERNATIONAL SYMPOSIUM ON SIGNAL PROCESSING AND INFORMATION TECHNOLOGY (ISSPIT, 7 December 2015 (2015-12-07), pages 111 - 115, XP032857370, DOI: doi:10.1109/ISSPIT.2015.7394250 *
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