JP2006005693A

JP2006005693A - Wavelength converter arrangement design method and apparatus

Info

Publication number: JP2006005693A
Application number: JP2004180475A
Authority: JP
Inventors: Eiji Oki; 英司大木; Daisaku Shimazaki; 大作島崎; Kohei Shiomoto; 公平塩本
Original assignee: Nippon Telegraph and Telephone Corp
Current assignee: NTT Inc
Priority date: 2004-06-18
Filing date: 2004-06-18
Publication date: 2006-01-05
Anticipated expiration: 2024-06-18
Also published as: JP4319950B2

Abstract

【課題】短時間で波長変換器の配置設計を実行することのできる波長変換器配置設計方法およびその装置を提供する。
【解決手段】設計パラメータ入力部２と、波長変換器を配置するための初期値を入力する波長変換器配置初期値入力部３と、入力された設計パラメータと前記波長変換器配置初期値とに基づいてＲＷＡシミュレーションを実行するＲＷＡシミュレータ部４と、ＲＷＡシミュレーションの結果から波長変換器再配置指標を抽出する波長変換器再配置指標抽出部５と、得られた波長変換器再配置指標に基づいて、波長変換器を再配置する波長変換器再配置部６と、再配置前の波長変換器の配置と再配置後の波長変換器の配置とを比較して、波長変換器配置変動値を求めることにより、配置の変動を判定する波長変換器配置変動判定部７と、前記波長変換器配置変動値が収束するとき、その波長変換器配置を出力する波長変換器配置出力部８とを備えた。
【選択図】図１PROBLEM TO BE SOLVED: To provide a wavelength converter arrangement design method and apparatus capable of executing wavelength converter arrangement design in a short time.
SOLUTION: A design parameter input unit 2, a wavelength converter arrangement initial value input unit 3 for inputting an initial value for arranging a wavelength converter, an inputted design parameter, and the wavelength converter arrangement initial value. RWA simulator unit 4 that executes RWA simulation based on, wavelength converter rearrangement index extraction unit 5 that extracts a wavelength converter rearrangement index from the result of RWA simulation, and based on the obtained wavelength converter rearrangement index The wavelength converter rearrangement unit 6 that rearranges the wavelength converter and the arrangement of the wavelength converter before the rearrangement and the arrangement of the wavelength converter after the rearrangement are compared to obtain the wavelength converter arrangement variation value. Thus, a wavelength converter arrangement fluctuation determining unit 7 for determining an arrangement fluctuation and a wavelength converter arrangement output unit 8 for outputting the wavelength converter arrangement when the wavelength converter arrangement fluctuation value converges are provided. Yeah.
[Selection] Figure 1

Description

本発明は、波長多重ネットワークにおける波長変換器配置設計方法およびその装置に関するものである。 The present invention relates to a wavelength converter arrangement design method and apparatus in a wavelength division multiplexing network.

図３は、従来例を示す波長変換器配置設計装置の機能ブロック図である。従来、この種の波長変換器配置設計装置としては、例えば、図３に示すような波長変換器配置設計装置１０が知られている。これは、設計パラメータを入力する設計パラメータ入力部２と、ＲＷＡシミュレータ部４（ＲＷＡについては後に詳述する）と、すべての波長変換器の配置候補を生成する波長変換器配置候補生成部１１と、波長変換器配置指標（後に詳述する）を抽出する波長変換器配置指標抽出部１２と、最適の波長変換器配置を波長変換器配置指標から判定する最適波長変換器配置判定部１３と、選択された波長変換器配置を出力する波長変換器配置出力部８とからなる。 FIG. 3 is a functional block diagram of a wavelength converter arrangement design apparatus showing a conventional example. Conventionally, as this type of wavelength converter arrangement design apparatus, for example, a wavelength converter arrangement design apparatus 10 as shown in FIG. 3 is known. This includes a design parameter input unit 2 for inputting design parameters, an RWA simulator unit 4 (RWA will be described in detail later), a wavelength converter arrangement candidate generation unit 11 for generating arrangement candidates for all wavelength converters, A wavelength converter arrangement index extraction unit 12 for extracting a wavelength converter arrangement index (to be described in detail later), an optimum wavelength converter arrangement determination unit 13 for determining an optimum wavelength converter arrangement from the wavelength converter arrangement index, The wavelength converter arrangement output unit 8 outputs the selected wavelength converter arrangement.

ここで、ＲＷＡ（Routing and Wavelength Assignment）について説明する。例えば、非特許文献１および非特許文献２に記載されているようなトランク型の光クロスコネクトノードにおいて、波長パスの保留時間が有限時間であるとする。波長パスの設定要求が生じて、波長パスが任意の波長を収容可能であれば、波長パスが設定され、保留時間後に波長パスが解除される。また、波長パスが任意の波長を収容不可能であれば、波長パス設定要求が拒絶される。そこで、波長パスを設定するためには、波長パスの経路、各リンクで使用すべき波長を決定する問題を解くことになる。これをＲＷＡ問題という。ＲＷＡ問題を解くということは、波長変換器を各ノードで使用するか否かを決定することになる。 Here, RWA (Routing and Wavelength Assignment) will be described. For example, in the trunk type optical cross-connect node as described in Non-Patent Document 1 and Non-Patent Document 2, it is assumed that the wavelength path hold time is a finite time. If a wavelength path setting request is generated and the wavelength path can accommodate any wavelength, the wavelength path is set and the wavelength path is released after the holding time. If the wavelength path cannot accommodate any wavelength, the wavelength path setting request is rejected. Therefore, in order to set the wavelength path, the problem of determining the wavelength path route and the wavelength to be used in each link is solved. This is called the RWA problem. Solving the RWA problem determines whether a wavelength converter is used at each node.

次に、波長変換器配置指標について説明する。波長変換器配置指標とは、例えば、波長パスの設定要求が拒絶される確率、すなわち、呼損率である。波長変換器配置指標を最小にするとは、ネットワーク全体の呼損率を最小にすると定義することであり、また、波長変換器配置指標を最小にするとは、発着ノードごとの呼損率を計測して、呼損率の最大値を最小にすると定義することである。 Next, the wavelength converter arrangement index will be described. The wavelength converter arrangement index is, for example, a probability that a wavelength path setting request is rejected, that is, a call loss rate. To minimize the wavelength converter placement index is to define that the call loss rate of the entire network is to be minimized, and to minimize the wavelength converter placement index, to measure the call loss rate for each source and destination node, The maximum value is defined as the minimum.

図４は、従来例を示す波長変換器配置設計方法のフローチャートである。従来の波長変換器の配置設計方法を図４を用いて説明する。ここでは、ネットワーク全体で配置できる波長変換器数をＹとする。ネットワーク内のノード数をｎ、ノードｉに配置する波長変換器ｘ_i、波長変換器の配置をｘ（下線はベクトルを表す。）とする。ｘ、Ｙは、｛ｘ₀、ｘ₁、…、ｘ_n-1｝、Ｙ＝Σ_iｘ_iとなる。Ｙ＝Σ_iｘ_iの制約の下で、波長変換器配置
指標が最小となるｘを求める。 FIG. 4 is a flowchart of a wavelength converter arrangement design method showing a conventional example. A conventional wavelength converter arrangement design method will be described with reference to FIG. Here, Y is the number of wavelength converters that can be arranged in the entire network. The number of nodes in the network n, node wavelength converter disposed in i x _i, the x arrangement of the wavelength converter (underlined represent vectors.) And. x and Y are {x ₀ , x ₁ ,..., x _n−1 }, and Y = Σ _i x _i . Under the constraint of Y = Σ _i x _i , x that minimizes the wavelength converter placement index is obtained.

設計パラメータが設計パラメータ入力部２から入力される（Ｓ１１）。設計パラメータとしては、物理トポロジ、波長の数、リンクコスト、ノード間のトラヒック需要などがある。トラヒック需要は、例えば、波長パスの発着ノードにおいて、波長パス設定要求の到着率分布、保留時間分布で表現される。 Design parameters are input from the design parameter input unit 2 (S11). Design parameters include physical topology, number of wavelengths, link cost, traffic demand between nodes, and the like. The traffic demand is expressed by, for example, the arrival rate distribution and the hold time distribution of the wavelength path setting request at the arrival and departure nodes of the wavelength path.

次に、波長変換器配置候補生成部１１が、Ｙ＝Σ_iｘ_iを満足するｘ＝｛ｘ₀、ｘ₁、…、ｘ_n-1｝のすべての候補を列挙する（Ｓ１２）。 Next, the wavelength converter arrangement candidate generation unit 11 lists all candidates of x = {x ₀ , x ₁ ,..., X _n−1 } that satisfy Y = Σ _i x _i (S12).

そして、波長変換器配置候補生成部１１が、ステップＳ１２で列挙された中から、試行する波長変換器配置候補ｘを選択する（Ｓ１３）。 Then, the wavelength converter arrangement candidate generation unit 11 selects the wavelength converter arrangement candidate x to be tried from among those listed in step S12 (S13).

続いて、ステップＳ１１で取得した設計パラメータとステップＳ１３で選択されたｘに対して、ＲＷＡシミュレータ部４において、ＲＷＡを行うシミュレータを実行させて、ＲＷＡ問題を解く（Ｓ１４）。 Subsequently, the RWA simulator unit 4 executes a RWA simulator for the design parameters acquired in step S11 and x selected in step S13, and solves the RWA problem (S14).

次に、波長変換器配置指標抽出部１２が、ＲＷＡシミュレータ部４から、得られた波長変換器配信指標を取得する（Ｓ１５）。 Next, the wavelength converter arrangement index extraction unit 12 acquires the obtained wavelength converter distribution index from the RWA simulator unit 4 (S15).

波長変換器配置候補生成部１１が、波長変換器配置候補ｘのすべてを確かめたか否かを確認する（Ｓ１６）。すべてを確かめた（Ｓ１６のＹｅｓ）ならば、ステップＳ１７へ進み、すべてを確かめていない（Ｓ１６のＮｏ）ならば、ステップＳ１３に戻る。 The wavelength converter arrangement candidate generation unit 11 confirms whether all of the wavelength converter arrangement candidates x have been confirmed (S16). If everything has been confirmed (Yes in S16), the process proceeds to step S17, and if all has not been confirmed (No in S16), the process returns to step S13.

次に、最適波長変換器配置判定部１３が、波長変換器配置指標が最適となる波長変換器配置ｘを選択する（Ｓ１７）。 Next, the optimum wavelength converter arrangement determination unit 13 selects the wavelength converter arrangement x that optimizes the wavelength converter arrangement index (S17).

最後に、波長変換器配置出力部８が最適の波長変換器配置ｘを出力する（Ｓ１８）。図５に波長変換器の配置例を示す。
E. Oki, D. Shimazaki, K. Shiomoto, N. Matsuura, W. Imajuku, and N. Yamanaka, “Performance of Distributed-Controlled Dynamic Wavelength-Conversion GMPLS Networks”,International Conference on Optical Communications and Networks(ICOCN 2002), Singapore, Nov. 2002 K. Sato, N. Yamanaka, Y. Takigawa, M. Koga, S. Okamoto, K. Shiomoto, E. Oki, and W. Imajuku, “GMPLS-based Photonic Multilayer Router (Hikari Router) Architecture: An Overview of Traffic Engineering and Signaling Technology”,IEEE Community Magazine, vol. 40, no.3, p.96-101, Mar. 2002. Finally, the wavelength converter arrangement output unit 8 outputs the optimum wavelength converter arrangement x (S18). FIG. 5 shows an arrangement example of the wavelength converter.
E. Oki, D. Shimazaki, K. Shiomoto, N. Matsuura, W. Imajuku, and N. Yamanaka, “Performance of Distributed-Controlled Dynamic Wavelength-Conversion GMPLS Networks”, International Conference on Optical Communications and Networks (ICOCN 2002) , Singapore, Nov. 2002 K. Sato, N. Yamanaka, Y. Takigawa, M. Koga, S. Okamoto, K. Shiomoto, E. Oki, and W. Imajuku, “GMPLS-based Photonic Multilayer Router (Hikari Router) Architecture: An Overview of Traffic Engineering and Signaling Technology ”, IEEE Community Magazine, vol. 40, no.3, p.96-101, Mar. 2002.

しかしながら、従来の波長変換器配置設計方法およびその装置では、前記した図４のステップＳ１２で列挙する組み合わせの数は、ノード数に対して指数関数的に増加する。そのため、ステップＳ１３からステップＳ１６までの繰り返し回数が膨大な数になる。特に、ステップＳ１４でのシミュレーションに時間を要するので、繰り返し回数が膨大になると、最適な波長変換器配置ｘを求めるために、膨大な時間を要することになり、最適な波長変換器配置を求めることが困難であるという問題点があった。 However, in the conventional wavelength converter arrangement design method and apparatus therefor, the number of combinations listed in step S12 of FIG. 4 described above increases exponentially with respect to the number of nodes. Therefore, the number of repetitions from step S13 to step S16 is enormous. In particular, since the simulation in step S14 takes time, if the number of repetitions is enormous, it takes a long time to obtain the optimum wavelength converter arrangement x , and the optimum wavelength converter arrangement is obtained. There was a problem that it was difficult.

本発明は、前記問題点に鑑みてなされたものであり、その目的とするところは、短時間で波長変換器の配置設計を実行することのできる波長変換器配置設計方法およびその装置を提供することにある。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a wavelength converter arrangement design method and apparatus capable of executing the wavelength converter arrangement design in a short time. There is.

本発明は、前記目的を達成するために、設計パラメータ入力部と、ＲＷＡシミュレータ部とを備え、入力された設計パラメータを用いてＲＷＡシミュレーションを実行することにより、波長変換器を備えた光クロスコネクトノードから構成される波長パスネットワークの波長変換器配置設計を行う波長変換器配置設計装置において、波長変換器を配置するための初期値を入力する波長変換器配置初期値入力部と、ＲＷＡシミュレーションの結果から波長変換器再配置指標を抽出する波長変換器再配置指標抽出部と、得られた波長変換器再配置指標に基づいて、波長変換器を再配置する波長変換器再配置部と、再配置前の波長変換器の配置と再配置後の波長変換器の配置とを比較して、波長変換器配置変動値を求めることにより、配置の変動を判定する波長変換器配置変動判定部と、前記波長変換器配置変動値が収束するとき、その波長変換器配置を出力する波長変換器配置出力部とを備え、前記ＲＷＡシミュレータ部は、入力された前記設計パラメータと前記波長変換器配置初期値とに基づいてＲＷＡシミュレーションを実行するようにしている。これにより、初期値と設計パラメータとに基づいてＲＷＡシミュレーションを実行し、波長変換器の再配置を実行し、再配置前の波長変換器の配置と再配置後の波長変換器の配置とを比較して、波長変換器配置変動値を求め、この値が収束すれば、当該波長変換器の配置を出力する。 To achieve the above object, the present invention includes a design parameter input unit and an RWA simulator unit, and executes an RWA simulation using the input design parameters, thereby providing an optical cross-connect including a wavelength converter. In a wavelength converter arrangement design apparatus that performs wavelength converter arrangement design of a wavelength path network composed of nodes, a wavelength converter arrangement initial value input unit that inputs an initial value for arranging a wavelength converter, and an RWA simulation A wavelength converter rearrangement index extraction unit that extracts a wavelength converter rearrangement index from the result; a wavelength converter rearrangement unit that rearranges the wavelength converter based on the obtained wavelength converter rearrangement index; Compare the placement of the wavelength converter before placement with the placement of the wavelength converter after rearrangement, and find the variation in placement of the wavelength converter by calculating the wavelength converter placement variation value. And a wavelength converter arrangement output unit that outputs the wavelength converter arrangement when the wavelength converter arrangement fluctuation value converges, and the RWA simulator unit is input An RWA simulation is executed based on the design parameter and the wavelength converter arrangement initial value. As a result, RWA simulation is executed based on the initial value and the design parameter, the wavelength converter is rearranged, and the wavelength converter before the rearrangement is compared with the wavelength converter after the rearrangement. Then, the wavelength converter arrangement variation value is obtained, and when this value converges, the arrangement of the wavelength converter is output.

本発明によれば、初期値と設計パラメータとに基づいてＲＷＡシミュレーションを実行し、波長変換器の再配置を実行し、再配置前の波長変換器の配置と再配置後の波長変換器の配置とを比較して、波長変換器配置変動値を求め、この値が収束すれば、当該波長変換器の配置を出力するので、効率よく短時間で波長変換器の配置を求めることができる。 According to the present invention, the RWA simulation is executed based on the initial value and the design parameter, the wavelength converter is rearranged, the wavelength converter before the rearrangement, and the wavelength converter after the rearrangement. And the wavelength converter arrangement variation value is obtained, and if this value converges, the arrangement of the wavelength converter is output, so that the arrangement of the wavelength converter can be obtained efficiently and in a short time.

図１および図２は、本発明の一実施形態を示すもので、図１は波長変換器配置設計装置の機能ブロック図である。図２は、本発明の一実施形態を示す波長変換器配置設計方法のフローチャートである。 1 and 2 show an embodiment of the present invention, and FIG. 1 is a functional block diagram of a wavelength converter arrangement design apparatus. FIG. 2 is a flowchart of a wavelength converter arrangement design method showing an embodiment of the present invention.

この波長変換器配置設計装置１は、設計パラメータを入力する設計パラメータ入力部２と、波長変換器を配置するための初期値を入力する波長変換器配置初期値入力部３と、入力された設計パラメータと波長変換器配置初期値を用いてＲＷＡシミュレーションを実行するＲＷＡシミュレータ部４と、ＲＷＡシミュレーションの結果から波長変換器再配置指標（後に詳述する）を抽出する波長変換器再配置指標抽出部５と、得られた波長変換器再配置指標に基づいて波長変換器を再配置する波長変換器再配置部６と、波長変換器の配置のＲＷＡシミュレーション前の配置と比較して、ＲＷＡシミュレーション後の配置の変動を判定する配置波長変換器配置変動判定部７と、決定した波長変換器の配置を出力する波長変換器配置出力部８とから構成されている。 This wavelength converter arrangement design device 1 includes a design parameter input unit 2 for inputting design parameters, a wavelength converter arrangement initial value input unit 3 for inputting initial values for arranging the wavelength converter, and the inputted design. RWA simulator unit 4 that executes RWA simulation using parameters and wavelength converter arrangement initial values, and wavelength converter rearrangement index extraction unit that extracts a wavelength converter rearrangement index (described in detail later) from the RWA simulation result 5 and the wavelength converter rearrangement unit 6 that rearranges the wavelength converter based on the obtained wavelength converter rearrangement index, and after the RWA simulation compared to the arrangement of the wavelength converter before the RWA simulation. The arrangement wavelength converter arrangement fluctuation determining unit 7 for determining the arrangement fluctuation of the wavelength converter, and the wavelength converter arrangement output unit 8 for outputting the determined arrangement of the wavelength converter. It is.

以上のように構成された波長変換器配置設計装置１を用いて実行する波長変換器配置設計方法について、図２を用いて説明する。ここでは、ネットワーク全体で配置できる波長変換器数をＹとする。ネットワーク内のノード数をｎ、ノードｉに配置する波長変換器をｘ_i、波長変換器の配置をｘとする。ｘ、Ｙは、ｘ＝｛ｘ₀、ｘ₁、…、ｘ_n-1｝、Ｙ＝Σ_iｘ_iとなる。Ｙ＝Σ_iｘ_iの制約の下で、波長変換器再配置指標が最小となるｘを求
める。 A wavelength converter arrangement design method executed using the wavelength converter arrangement design apparatus 1 configured as described above will be described with reference to FIG. Here, Y is the number of wavelength converters that can be arranged in the entire network. The number of nodes in the network n, the x _i wavelength converter disposed in node i, the arrangement of the wavelength converter and x. x and Y are x = {x ₀ , x ₁ ,..., x _n−1 }, and Y = Σ _i x _i . Under the constraint of Y = Σ _i x _i , x that minimizes the wavelength converter relocation index is obtained.

初めに、設計パラメータ入力部２において、設計パラメータを入力する（Ｓ１）。設計パラメータとしては、物理トポロジ、波長の数、リンクコスト、ノード間のトラヒック需要がある。トラヒック需要は、例えば、波長パスの発着ノードにおいて、波長パス設定要求の到着率分布、保留時間分布で表される。 First, design parameters are input in the design parameter input unit 2 (S1). Design parameters include physical topology, number of wavelengths, link cost, and traffic demand between nodes. The traffic demand is expressed by, for example, the arrival rate distribution and the hold time distribution of the wavelength path setting request at the arrival and departure nodes of the wavelength path.

次に、波長変換器配置初期値入力部３において、波長変換器配置初期値を入力する（Ｓ２）。ここで、初期値は、Ｙ＝Σ_iｘ_iを満足するｘ＝｛ｘ₀、ｘ₁、…、ｘ_n-1｝を設定する。初期値としては、例えば、ｘ_i＝Ｙ／（ｎ−１）と設定することができる。ｘ_iは整数である必要があるので、必要に応じて、小数点以下を切り上げたり、切り下げたりする。 Next, the wavelength converter arrangement initial value input unit 3 inputs the wavelength converter arrangement initial value (S2). Here, as an initial value, x = {x ₀ , x ₁ ,..., X _n−1 } that satisfies Y = Σ _i x _i is set. As an initial value, for example, x _i = Y / (n−1) can be set. Since x _i needs to be an integer, the number after the decimal point is rounded up or down as necessary.

次に、ＲＷＡシミュレータ部４において、ＲＷＡシミュレータを起動し、入力された設計パラメータと波長変換器配置初期値に基づいて、ＲＷＡシミュレーションを実行し、ＲＷＡ問題を解く（Ｓ３）。 Next, in the RWA simulator unit 4, the RWA simulator is activated, RWA simulation is executed based on the input design parameters and wavelength converter arrangement initial values, and the RWA problem is solved (S3).

続いて、波長変換器再配置指標抽出部５が、ＲＷＡシミュレーションの結果に基づいて、波長変換器再配置指標を算出する（Ｓ４）。波長変換器再配置指標には次のような指標が考えられる。各ノードにおいて設置されている波長変換器に対して、波長変換器が使用されている割合、すなわち、波長変換器使用率や、各ノードにおいて使用されている波長変換器の個数の平均、すなわち、波長変換器平均使用個数や、波長連続制約条件が満足されない場合に、波長変換器を使用することを試みるとき、当該ノードで利用可能な波長変換器がないために生じる波長パス設定のブロッキング確率、すなわち、波長変換器ブロッキング率（ファイバ内の利用可能な波長が無いために生じるブロッキングは、利用可能な波長変換器の個数に依存しないので、波長変換器ブロッキングとして数えない）などが考えられる。 Subsequently, the wavelength converter rearrangement index extraction unit 5 calculates a wavelength converter rearrangement index based on the result of the RWA simulation (S4). The following indices can be considered as the wavelength converter rearrangement indices. The ratio of the wavelength converters used to the wavelength converters installed at each node, that is, the wavelength converter usage rate and the average number of wavelength converters used at each node, that is, When the average number of wavelength converters used or the wavelength continuity constraint is not satisfied, when trying to use a wavelength converter, the blocking probability of the wavelength path setting that occurs because there is no wavelength converter available at the node, That is, a wavelength converter blocking rate (blocking that occurs because there is no usable wavelength in the fiber does not depend on the number of available wavelength converters, and therefore cannot be counted as wavelength converter blocking).

そして、波長変換器再配置部６において、得られた波長変換器再配置指標に基づいて、波長変換器再配置を実施する（Ｓ５）。例えば、Ｙ＝Σ_iｘ_iを満足するｘ＝｛ｘ₀、ｘ₁、…、ｘ_n-1｝を、波長変換器再配置指標に波長変換器の個数を比例させて、波長変換器を配置する、または、波長変換器再配置指標の対数に個数を比例させて、波長変換器を配置する。 Then, the wavelength converter rearrangement unit 6 performs wavelength converter rearrangement based on the obtained wavelength converter rearrangement index (S5). For example, x = {x ₀ , x ₁ ,..., X _n−1 } satisfying Y = Σ _i x _i is proportional to the number of wavelength converters in the wavelength converter rearrangement index, and the wavelength converter is The wavelength converter is arranged by arranging or by making the number proportional to the logarithm of the wavelength converter rearrangement index.

次に、波長変換器配置変動判定部７において、波長変換器を再配置する前のｘ(before)と再配置後のｘ(after)との差分をとり、波長変換器配置変動値Ｖを算出する。波長変換器変動値Ｖを、例えば、

Ｖ＝Σ_i｜ｘ_i(before)−ｘ_i(after)｜
または、
Ｖ＝Σ_i｜ｘ_i(before)−ｘ_i(after)｜²

と定義する。この波長変換器変動値Ｖが、閾値Ｖ_th以下であれば、収束と判定し、ステップＳ７に進む。閾値Ｖ_thより大きければ、収束していないと判断して、ステップＳ３に戻る（Ｓ６）。ステップＳ３ではｘ(after)を用いて、ＲＷＡシミュレーションを行う。 Next, the wavelength converter arrangement fluctuation determining unit 7 calculates the wavelength converter arrangement fluctuation value V by calculating the difference between x (before) before the wavelength converter is rearranged and x (after) after the rearrangement. To do. The wavelength converter fluctuation value V is, for example,

V = Σ _i | x _i (before) −x _i (after) |
Or
V = Σ _i | x _i (before) −x _i (after) | ²

It is defined as If the wavelength converter fluctuation value V is equal to or less than the threshold value V _th , it is determined that convergence has occurred and the process proceeds to step S7. If it is larger than the threshold value V _th , it is determined that it has not converged, and the process returns to step S3 (S6). In step S3, RWA simulation is performed using x (after).

最後に、ステップＳ６で波長変換器変動値Ｖが収束した波長変換器配置ｘを、波長変換器配置出力部８において出力する。 Finally, the wavelength converter arrangement x in which the wavelength converter fluctuation value V has converged in step S6 is output from the wavelength converter arrangement output unit 8.

本発明の一実施形態を示す波長変換器配置設計装置の機能ブロック図である。It is a functional block diagram of the wavelength converter arrangement design device showing one embodiment of the present invention. 本発明の一実施形態を示す波長変換器配置設計方法のフローチャートである。It is a flowchart of the wavelength converter arrangement design method which shows one Embodiment of this invention. 従来例を示す波長変換器配置設計装置の機能ブロック図である。It is a functional block diagram of the wavelength converter arrangement design apparatus which shows a prior art example. 従来例を示す波長変換器配置設計方法のフローチャートである。It is a flowchart of the wavelength converter arrangement design method which shows a prior art example. 波長変換器の配置例を示す図である。It is a figure which shows the example of arrangement | positioning of a wavelength converter.

Explanation of symbols

１波長変換器配置設計装置
２設計パラメータ入力部
３波長変換器配置初期値入力部
４ＲＷＡシミュレータ部
５波長変換器再配置指標抽出部
６波長変換器再配置部
７波長変換器配置変動判定部
８波長変換器配置出力部 DESCRIPTION OF SYMBOLS 1 Wavelength converter arrangement design apparatus 2 Design parameter input part 3 Wavelength converter arrangement initial value input part 4 RWA simulator part 5 Wavelength converter rearrangement index extraction part 6 Wavelength converter rearrangement part 7 Wavelength converter arrangement fluctuation determination part 8 Wavelength converter arrangement output section

Claims

Wavelength converter of wavelength path network composed of trunk-type optical cross-connect node having wavelength converter by executing RWA simulation in RWA simulator using design parameter input from design parameter input unit In the wavelength converter layout design method for performing layout design,
In the wavelength converter arrangement initial value input section, a procedure for inputting the wavelength converter arrangement initial value,
The RWA simulator unit executes a RWA simulation based on the input design parameters and wavelength converter arrangement initial values, and solves the RWA problem;
The wavelength converter rearrangement index extraction unit extracts a wavelength converter rearrangement index based on the result of the RWA simulation;
The wavelength converter rearrangement unit executes the wavelength converter rearrangement based on the extracted wavelength converter rearrangement index; and
Wavelength converter placement variation determination unit compares the placement of the wavelength converter before the rearrangement with the placement of the wavelength converter after the rearrangement, and determines the variation in the placement by obtaining the wavelength converter placement variation value. And the steps to
A wavelength converter arrangement design method comprising: a wavelength converter arrangement output unit that outputs the wavelength converter arrangement when the wavelength converter arrangement variation value converges.

The wavelength converter arrangement according to claim 1, wherein the wavelength converter rearrangement index is a ratio in which the wavelength converter is used with respect to the wavelength converter installed in each node. Design method.

The wavelength converter arrangement design method according to claim 1, wherein the wavelength converter rearrangement index is an average of the number of wavelength converters used in each node.

The wavelength converter relocation index is a wavelength generated when there is no wavelength converter available at the node when attempting to use the wavelength converter when the wavelength continuity constraint is not satisfied at each node. The wavelength converter arrangement design method according to claim 1, wherein a blocking probability of path setting.

The wavelength converter is arranged by making the number of wavelength converters proportional to the wavelength converter rearrangement index when the wavelength converter is rearranged based on the wavelength converter rearrangement index. The wavelength converter arrangement design method according to any one of claims 4 to 4.

When the wavelength converter is rearranged based on the wavelength converter rearrangement index, the wavelength converter is arranged such that the number of wavelength converters is proportional to the logarithm of the wavelength converter rearrangement index. The wavelength converter arrangement design method according to any one of claims 1 to 4.

The determination of convergence refers to the difference between x (before) before the wavelength converter is rearranged (the underline represents a vector. The same applies hereinafter) and x (after) after the rearrangement. calculates the variation value V, the wavelength converter disposed variation value V = Σ _i | claims, characterized in that determining that it is below the threshold _{_{V th | x i (before)}} -x i (after) The wavelength converter arrangement design method according to any one of claims 1 to 6.

The determination of convergence refers to the difference between x (before) before the wavelength converter is rearranged and x (after) after the rearrangement, and calculates the wavelength converter arrangement fluctuation value V to calculate the wavelength converter arrangement. Fluctuation value V = Σ _i | x _i
_{(before) -x i (after)} | 2 is the wavelength converter layout design method according to any one of claims 1 to 6, characterized in that determining that it is below the threshold V _th.

A wavelength converter of a wavelength path network comprising an optical cross-connect node having a wavelength converter by executing a RWA simulation using the input design parameter by including a design parameter input unit and an RWA simulator unit In the wavelength converter layout design device that performs layout design,
A wavelength converter arrangement initial value input unit for inputting an initial value for arranging the wavelength converter;
A wavelength converter rearrangement index extraction unit that extracts a wavelength converter rearrangement index from the result of the RWA simulation;
Based on the obtained wavelength converter rearrangement index, a wavelength converter rearrangement unit that rearranges the wavelength converter,
A wavelength converter arrangement fluctuation determination unit that determines the fluctuation of the arrangement by comparing the arrangement of the wavelength converter before the rearrangement and the arrangement of the wavelength converter after the rearrangement to obtain a wavelength converter arrangement fluctuation value; ,
A wavelength converter arrangement output unit for outputting the wavelength converter arrangement when the wavelength converter arrangement variation value converges, and
The RWA simulator unit is configured to execute an RWA simulation based on the inputted design parameters and the wavelength converter arrangement initial value.

The wavelength converter arrangement according to claim 9, wherein the wavelength converter rearrangement index is a ratio in which the wavelength converter is used with respect to the wavelength converter installed in each node. Design equipment.

The wavelength converter arrangement design apparatus according to claim 9, wherein the wavelength converter rearrangement index is an average of the number of wavelength converters used in each node.

The wavelength converter relocation index is a wavelength generated when there is no wavelength converter available at the node when attempting to use the wavelength converter when the wavelength continuity constraint is not satisfied at each node. The wavelength converter arrangement design device according to claim 9, wherein a blocking probability of path setting.

The wavelength converter is arranged by making the number of wavelength converters proportional to the wavelength converter rearrangement index when the wavelength converter is rearranged based on the wavelength converter rearrangement index. The wavelength converter arrangement design device according to any one of claims 12 to 12.

When the wavelength converter is rearranged based on the wavelength converter rearrangement index, the wavelength converter is arranged such that the number of wavelength converters is proportional to the logarithm of the wavelength converter rearrangement index. Item 13. The wavelength converter arrangement design device according to any one of Items 9 to 12.

The determination of convergence refers to the difference between x (before) before the wavelength converter is rearranged and x (after) after the rearrangement, and calculates the wavelength converter arrangement fluctuation value V to calculate the wavelength converter arrangement. Fluctuation value V = Σ _i | x
The wavelength converter arrangement design apparatus according to claim 9, wherein _i (before) −x _i (after) | is determined to be equal to or less than a threshold value V _th .

The determination of convergence refers to the difference between x (before) before the wavelength converter is rearranged and x (after) after the rearrangement, and calculates the wavelength converter arrangement fluctuation value V to calculate the wavelength converter arrangement. Fluctuation value V = Σ _i | x
_{_{i (before) -x i (after}} ) | 2 is the wavelength converter layout design apparatus according to any one of claims 9 to 14, wherein the determining that it is below the threshold V _th .