JP6938928B2 - Optical transmission performance estimation device and optical transmission performance estimation method - Google Patents

Description

The techniques described herein relate to optical transmission performance estimation devices and optical transmission performance estimation methods.

The optical communication system may be designed before the provision of the communication service based on the system conditions given in advance. Since the actual parameters cannot be measured before the communication service is provided, the optical communication system may be designed using the value considering the margin.

Japanese Unexamined Patent Publication No. 2012-15966 Japanese Unexamined Patent Publication No. 2010-81297 U.S. Patent Publication No. 2010/0142943 U.S. Patent Publication No. 2013/0236169 Japanese Unexamined Patent Publication No. 2007-6008 Japanese Unexamined Patent Publication No. 2014-165818

However, it is difficult to set an appropriate margin in the design of an optical communication system. For example, if an excessive margin is input, a design value worse than the actual performance may be output, and the distance at which the signal light can be transmitted may be shorter than the actual distance.

In one aspect, the techniques described herein are one of the objectives of improving the estimation accuracy of optical transmission performance.

In one aspect, the optical transmission performance estimator transmits a group of spans between a first node and an nth (n is an integer of 3 or more) nodes in a signal light transmission path via a plurality of nodes. An index relating to the first transmission performance of the signal light to be transmitted and a second of the signal light transmitted in a span or a span group between the first node and a node of the m (natural number satisfying m <n). The span between the mth node and the nth node is transmitted based on the index related to the transmission performance of the above and the acquisition unit for acquiring the first and second transmission performance indexes. An estimation unit that estimates an index related to signal light transmission performance, a first storage unit that stores an index related to the first transmission performance acquired by the acquisition unit, and the m-th node estimated by the estimation unit. A second storage unit that stores an index relating to a third transmission performance of the signal light transmitted in the span between the first node and the nth node, and between the first node and the nth node. An actually measured value of an index relating to the transmission performance of the signal light transmitted through the span group, an index relating to the first transmission performance stored by the first storage unit, and the third storage unit stored by the second storage unit. It is provided with an update unit that updates the index related to the third transmission performance stored in the second storage unit based on the index related to the transmission performance.

One aspect is to improve the estimation accuracy of optical transmission performance.

It is a figure which shows an example of the transmission performance estimation in an optical communication system. It is a figure which shows an example of the wavelength path in the optical communication system shown in FIG. It is a figure which showed an example of the transmission quality quantity in the optical communication system shown in FIG. 1 in a table format. It is a figure which shows an example of the transmission quality deterioration in the optical communication system shown in FIG. It is a block diagram which shows the structural example of the optical communication system of 1st Embodiment. It is a block diagram which shows the configuration example of the node in the optical communication system shown in FIG. It is a block diagram which shows the configuration example of the estimation apparatus in the optical communication system shown in FIG. It is a figure which shows an example of the transmission performance estimation in the optical communication system shown in FIG. FIG. 5 is a diagram showing an example of transmission quality quantity information in the optical communication system shown in FIG. 5 in a table format. It is a flowchart explaining the transmission performance estimation operation in the optical communication system shown in FIG. It is a block diagram which shows the structural example of the optical communication system of the 1st modification of 1st Embodiment. It is a figure which shows an example of the transmission performance estimation in the optical communication system of the 2nd modification of 1st Embodiment. It is a figure which showed an example of the span group transmission quality quantity information in the optical communication system shown in FIG. 12 in a table format. It is a figure which showed an example of the transmission quality quantity information in the optical communication system of the 4th modification of 1st Embodiment in a table format. It is a flowchart explaining the transmission performance estimation operation in the optical communication system shown in FIG. It is a block diagram which shows the structural example of the optical communication system of the 7th modification of 1st Embodiment. It is a block diagram which shows the structural example of the optical communication system of 2nd Embodiment. It is a block diagram which shows the configuration example of the node in the optical communication system shown in FIG. It is a block diagram which shows the structural example of the estimation apparatus in the optical communication system shown in FIG. It is a figure which shows an example of the topology information for the route determination in the optical communication system shown in FIG. It is a figure explaining the example of the edge in the topology information shown in FIG. It is a figure explaining an example of the 1st constraint condition. It is a figure explaining an example of the 2nd constraint condition. It is a figure explaining an example of the 3rd constraint condition. It is a figure which shows an example of the determined route. It is a flowchart explaining the route determination operation and the transmission performance estimation operation in the optical communication system shown in FIG. It is a figure which shows an example of the path determined in the modification of 2nd Embodiment.

Hereinafter, embodiments will be described with reference to the drawings. However, the embodiments shown below are merely examples, and there is no intention of excluding the application of various modifications and techniques not specified in the embodiments. For example, the present embodiment can be variously modified and implemented without departing from the spirit of the present embodiment.

Further, each figure does not mean that it includes only the components shown in the figure, but may include other components. Hereinafter, in the drawings, the parts having the same reference numerals indicate the same or similar parts unless otherwise specified.

[A] First Embodiment [A-1] System Configuration Example FIG. 1 is a diagram showing an example of transmission performance estimation in the optical communication system 100a.

In the optical communication system 100a shown in FIG. 1, each node 3a may be connected in a mesh shape in the same manner as in the optical communication system 100 of the first embodiment described later with reference to FIG. That is, in FIG. 1, one of a plurality of routes composed of a plurality of nodes 3a connected in a mesh shape is shown.

As shown in FIG. 1, the optical communication system 100a includes a plurality of nodes (N in the illustrated example) represented as nodes # 1 to # N.

Further, in FIG. 1, for the sake of explanation, the transmitter / receiver 4a (indicated as “Tx / Rx # 1 to # N”) provided in each node 3a is shown independently of each node 3a. .. In the example shown in FIG. 1, the nodes # 1 to #N may be provided with Tx / Rx # 1 to #N, respectively.

Each node 3a may be communicatively connected to each other by an optical fiber transmission line. The transmission section between the nodes 3a may be referred to as a "span". In the example shown in FIG. 1, the transmission section between node # 1 and node # 2 is referred to as span # 1, the transmission section between node # 2 and node # 3 is referred to as span # 2, and node # 2. The transmission section between 3 and node # 4 is referred to as span # 3. Further, the transmission section between node # N-1 (not shown in FIG. 1) and node # N is referred to as span # N-1.

In the optical communication system 100a shown in FIG. 1, the transmission quality quantity F between adjacent nodes 3a (in other words, “1 span”) is measured, respectively.

For example, by node # signal light from the first Tx / Rx # 1 to the node # 2 of the Tx / Rx # 2 is transmitted, the transmission quality quantity _{F 1} of the span # 1 may be measured (reference numeral A1) .. Further, by the signal light is transmitted to the node # 2 of the Tx / Rx # 2 from the node # 3 Tx / Rx # 3, transmission quality amount _{F 2} of the span # 2 may be measured (reference numeral A2) .. Further, the node # by the signal light is transmitted from the third Tx / Rx # 3 to the node # 4 of Tx / Rx # 4, the transmission quality amount _{F 3} of the span # 3 may be measured (reference numeral A3) ..

The transmission quality quantity F may be OSNR (Optical Signal-to-Noise Ratio) as an example. In the following description, it is assumed that the transmission quality quantity F is OSNR. As will be described later, the transmission quality quantity F may be indicated by an index other than OSNR.

ここで、Ｂｎは雑音帯域幅であり、Ｒｓは信号ボーレートである。 When the signal light transmission method between the nodes 3a is DP-QPSK, the transmission quality quantity F is converted from the BER (Bit Error Rate) measured in each span based on the following equation (1). It's okay. DP-QPSK is an abbreviation for Dual Polarization-Quadrature Phase Shift Keying.

Here, Bn is the noise bandwidth and Rs is the signal baud rate.

Since the transmission quality quantity F (OSNR in this case) converted from the BER conforms to the SNR (signal-to-noise ratio), a certain section (for example, from node # 1 to node #) is based on the following equation (2). The transmission quality quantity F (for example, F _{1-> 4} ) in the section up to 4) may be calculated.

FIG. 2 is a diagram showing an example of a wavelength path in the optical communication system 100a shown in FIG.

The wavelength path λ1 shown in FIG. 2 may be composed of spans AB and BC, and the wavelength path λ2 may be composed of spans BC, CD and DE. Further, the wavelength path λ3 may be composed of spans AB, BC, CD, DE, EF and FG. Further, the wavelength path λ4 may be composed of spans DE, EF and FG.

The wavelength paths λ1, λ2 and λ4 may be the wavelength paths in operation, and the wavelength paths λ3 may be the wavelength paths to be estimated by OSNR.

FIG. 3 is a diagram showing an example of the transmission quality quantity (in other words, “OSNR”) in the optical communication system 100a shown in FIG. 1 in a table format.

The OSNR of each span in the wavelength path λ3 to be estimated may be calculated based on the OSNR of each span in the other wavelength paths.

For example, the OSNR of the span AB in the wavelength path λ3 to be estimated may be calculated based on the OSNR of the span AB of the wavelength path λ1. At this time, since the table of FIG. 3 has one OSNR having the same span as the span AB in the wavelength path λ3, the OSNR of the span AB in the wavelength path λ1 is the span A− of the wavelength path λ3. It may be assigned to the OSNR of B.

The OSNR of the span BC in the wavelength path λ3 may be calculated based on the OSNR of the same span BC in the wavelength path λ1 and the wavelength path λ2. At this time, in the table of FIG. 3, there are two OSNRs having the same span as the span BC in the wavelength path λ3 (in other words, “plurality”), and the wavelength of the wavelength path λ3 is the wavelength path λ1. Not between and λ2. Therefore, the OSNR of the same span of the wavelength path λ3 may be calculated by linearly extrapolating the OSNR of the spans BC of the wavelength paths λ1 and λ2.

In the table of FIG. 3, since there is one OSNR having the same span as the span CD in the wavelength path λ3, the OSNR of the span CD of the wavelength path λ2 becomes the OSNR of the span CD of the wavelength path λ3. May be assigned.

The OSNR of the span DE in the wavelength path λ3 may be calculated based on the OSNR of the same span DE in the wavelength paths λ2 and λ4. At this time, in the table of FIG. 3, there are two OSNRs having the same span as the span DE in the wavelength path λ3 (in other words, “plurality”), and the wavelength of the wavelength path λ3 is the wavelength path λ2. Is between λ4 and λ4. Therefore, the OSNR of the same span DE in the wavelength path λ3 may be calculated by linear interpolation of the OSNR of the spans DE in the wavelength paths λ2 and λ4.

In the table of FIG. 3, since there is one OSNR having the same span as the span EF in the wavelength path λ3, the OSNR of the span EF in the wavelength path λ4 is the OSNR of the span EF in the wavelength path λ3. May be assigned to.

In the table of FIG. 3, since there is one OSNR having the same span as the span FG of the wavelength path λ3, the OSNR of the span FG in the wavelength path λ4 is the OSNR of the span FG of the wavelength path λ3. May be assigned.

ここで、ｋは、推定対象の波長パスに含まれるスパン数であってよい。 Then, the path OSNR may be calculated using the following equation (3) based on the OSNR of each span in the wavelength path λ3 to be estimated in the table of FIG.

Here, k may be the number of spans included in the wavelength path to be estimated.

FIG. 4 is a diagram showing an example of transmission quality deterioration in the optical communication system 100a shown in FIG.

Deterioration due to transmission of signal light over one span F _SPAN hardly includes signal quality deterioration due to non-linearity and signal quality deterioration due to band narrowing when signal light passes through an optical filter.

In other words, as shown in FIG. 4, the smaller the number of spans through which the signal light is transmitted, the smaller the change in the amount of transmission quality deterioration (see reference numeral B1). On the other hand, as the number of spans through which the signal light is transmitted increases, the change in the amount of transmission quality deterioration increases (see reference numeral B2).

Therefore, if the transmission quality amount when the signal light is transmitted over a large number of spans is estimated from _{the deterioration amount F SPAN} when the signal light is transmitted over one span, the estimation error may become large.

Therefore, in order to improve the estimation accuracy of the transmission performance, the optical communication system 100 of the first embodiment may have a functional configuration as described below.

FIG. 5 is a block diagram showing a configuration example of the optical communication system 100 of the first embodiment.

As shown in FIG. 5, the optical communication system 100 includes an estimation device 1, a control device 2, and a plurality of (five in the illustrated example) nodes 3 shown as nodes # 1 to # 5. To be equipped. The function as the estimation device 1 may be provided in the control device 2.

The control device 2 is an example of a network control device, and exemplarily controls the transmission of signal light by each node 3 provided in the network. The control device 2 may be communicably connected to the estimation device 1 and each node 3.

Further, the control device 2 estimates whether signal light can be transmitted from the start point node 3 to the end point node 3 of a certain path (which may be referred to as a “section” or “span group”). You may contact us. The start point node 3 may be the signal light transmission source node 3, and the end point node 3 may be the signal light transmission destination node 3.

By way of example, the node 3 transmits and receives signal light to and from another node 3 via a span. Each node 3 may be communicably connected to all or part of the other nodes 3 provided in the optical communication system 100 via a span. Further, each node 3 may transmit and receive signal light to and from the other node 3 which is not connected via the other node 3 which is connected.

In the example shown in FIG. 5, node # 1 is connected to nodes # 2 and # 5, node # 2 is connected to nodes # 1 and # 3-5, and node # 3 is connected to node # 2. And # 4 are connected. Further, node # 4 is connected to nodes # 2, # 3 and # 5, and node # 5 is connected to nodes # 1, # 2 and # 4.

FIG. 6 is a block diagram showing a configuration example of node 3 in the optical communication system 100 shown in FIG.

As shown in FIG. 6, the node 3 is exemplified as a node control unit 31, an optical branch insertion unit 32, an input amplifier 33, an output amplifier 34, a plurality of receiving units 35 shown as Rx, and Tx. A plurality of transmission units 36 are provided.

The input amplifier 33 schematically amplifies the signal light input from the optical fiber 37. The output amplifier 34, schematically, amplifies the signal light output to the optical fiber 38.

The Rx35 typically receives signal light. The Tx36 typically transmits signal light.

Illustratively, the optical branching insertion unit 32 has a function of optical branching a part of the signal light communicating through the wavelength path and inserting a new signal light into the signal light communicating with the wavelength path, and communicating the wavelength path. It has a function of adjusting the power of the signal light. The optical branch insertion unit 32 may optically branch the signal light and transmit the optically branched signal light to any Rx35. Further, the optical branch insertion unit 32 may optically insert the signal light from Tx36 into the signal light and output the light-inserted signal light to the optical fiber 38 via the output amplifier 34. Examples of the optical branch insertion unit 32 include an optical branch insertion device such as an OADM (Optical add-drop multiplexer).

The node control unit 31 controls the optical branch insertion unit 32, the input amplifier 33, and the output amplifier 34, for example. Further, the node control unit 31 may be communicably connected to the control device 2, cause Rx35 to measure the BER of the wavelength path, and notify the control device 2 of information including the measurement result of the BER. The information notified to the control device 2 may include path identification information for identifying the wavelength path, BER of the wavelength path, and the like.

FIG. 7 is a block diagram showing a configuration example of the estimation device 1 in the optical communication system 100 shown in FIG.

The estimation device 1 is an example of an optical transmission performance estimation device, and as shown in FIG. 7, includes a CPU (Central Processing Unit) 11 and a memory 12 as an example.

The memory 12 is, for example, a storage device including at least one of a non-volatile memory such as a ROM (Read Only Memory) and a volatile memory such as a RAM (Random Access Memory). A program such as BIOS (Basic Input / Output System) may be written in the ROM of the memory 12. The software program written in the ROM or RAM may be appropriately read and executed by the CPU 11. Further, the RAM of the memory 12 may be used as a primary recording memory or a working memory.

As shown in FIG. 7, the memory 12 includes, for example, a transmission quality information storage unit 121 and a BER threshold information storage unit 122.

The transmission quality information storage unit 121 typically stores transmission quality quantity information 1211 (described later with reference to FIG. 9) indicating a transmission quality quantity (in other words, a “quality deterioration amount”) in each span.

The BER threshold information storage unit 122 is capable of transmitting signal light, for example, using a certain path (in other words, a “section” or a “span group”) from the start point node 3 to the end point node 3. The BER threshold information indicating the above is stored.

The CPU 11 is, for example, a processing device that performs various controls and calculations, and realizes various functions by executing an OS (Operating System) or a program stored in the memory 12. That is, as shown in FIG. 7, the CPU 11 includes a transmission quality amount calculation unit 111, a transmission quality amount information management unit 112, a transmission performance calculation unit 113, a transmission possibility determination unit 114, a BER threshold information management unit 115, and an update amount calculation. It may function as part 116.

In order to realize the functions of the transmission quality amount calculation unit 111, the transmission quality amount information management unit 112, the transmission performance calculation unit 113, the transmission availability determination unit 114, the BER threshold information management unit 115, and the update amount calculation unit 116. The program may be recorded on a recording medium. The recording medium on which the program is recorded may be computer readable and may be, for example, a flexible disk, a CD, a DVD, a Blu-ray disk, a magnetic disk, an optical disk, a photomagnetic disk, or a semiconductor memory. The CD may be a CD-ROM, a CD-R, a CD-RW, or the like. The DVD may be a DVD-ROM, a DVD-RAM, a DVD-R, a DVD + R, a DVD-RW, a DVD + RW, an HD DVD, or the like. The semiconductor memory may be a flash memory such as various memory cards or a USB (Universal Serial Bus) memory.

Then, the computer (CPU 11 in the first embodiment) may read the program from the above-mentioned recording medium via a reading device (not shown), transfer the program to the internal recording device or the external recording device, store the program, and use the program. Further, the program may be recorded in a storage device (recording medium) such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, and provided to a computer from the storage device via a communication path.

When realizing each function of the CPU 11, the program stored in the internal storage device (memory 12 in the first embodiment) may be executed by the computer (CPU 11 in the first embodiment). Further, the computer may read and execute the program recorded on the recording medium.

The transmission quality quantity calculation unit 111 calculates the transmission quality quantity in each span, for example, based on the wavelength path information and the BER information notified from the control device 2. As shown with reference to FIG. 2, the wavelength path information may be information indicating one or a plurality of spans (in other words, “wavelength path”) in which signal light of each wavelength is transmitted. The BER information may be information indicating the BER of the signal light transmitted over one or more spans.

The control device 2 instructs the node 3 to be measured by the BER to transmit and / or receive the signal light, and causes the target node 3 to transmit and / or receive the signal light to span or span. BER information related to the signal light transmitted through the group may be measured or acquired. The measurement or acquisition of the BER information may be performed by causing the transmission quality quantity calculation unit 111 to transmit and receive signal light to the target node 3 via the control device 2.

The information acquired by the transmission quality quantity calculation unit 111 from the control device 2 is not limited to the BER information. For example, the transmission quality quantity calculation unit 111 may acquire information on the EVM (Error Vector Magnitude) from the control device 2. Further, the transmission quality quantity calculation unit 111 provides information on parameters such as OSNR, wavelength dispersion, polarization mode dispersion, PDL (polarization dependence loss), intrachannel nonlinearity, interchannel nonlinearity, mutual phase modulation, or band narrowing. May be obtained from the control device 2.

FIG. 8 is a diagram showing an example of transmission performance estimation in the optical communication system 100 shown in FIG.

In FIG. 8, one of a plurality of routes (see FIG. 5) composed of a plurality of nodes 3 connected in a mesh shape is shown.

In FIG. 8, the estimation device 1 and the control device 2 are not shown. Further, in FIG. 8, for the sake of explanation, the transmitter / receiver 4 (indicated as “Tx / Rx # 1 to # N”) provided in each node 3 is shown independently of each node 3. .. That is, Tx / Rx4 shown in FIG. 8 is an example of Tx36 and Rx35 shown in FIG. In the example shown in FIG. 8, the nodes # 1 to #N may be provided with Tx / Rx # 1 to #N, respectively.

Each node 3 may be communicatively connected to each other by an optical fiber transmission line. The transmission section between the nodes 3 may be referred to as a "span". In the example shown in FIG. 8, the transmission section between node # 1 and node # 2 is referred to as span # 1, the transmission section between node # 2 and node # 3 is referred to as span # 2, and node # 2. The transmission section between 3 and node # 4 is referred to as span # 3. Further, the transmission section between the node # N-1 (not shown in FIG. 8) and the node # N is referred to as a span # N-1.

In the example shown in FIG. 8, the transmission quality quantity calculation unit 111 receives wavelength path information indicating a span group composed of spans # 1 and # 2 (see reference numeral C1) and signal light transmitted through the span group. The BER information indicating the BER may be acquired from the control device 2.

Further, in the example shown in FIG. 8, the transmission quality quantity calculation unit 111 includes wavelength path information indicating a span group (see reference numeral C2) composed of spans # 1 to # 3 and a signal transmitted through the span group. BER information indicating the BER of light may be acquired from the control device 2.

Then, the transmission quality quantity calculation unit 111 of the span # 3 is based on the wavelength path information and the BER information related to the span group represented by the reference numeral C1 and the wavelength path information and the BER information related to the span group indicated by the reference numeral C2. The transmission quality quantity may be calculated. Hereinafter, the span for which the transmission quality quantity is calculated by the transmission quality quantity calculation unit 111 may be referred to as a target span.

ここで、Ｂｎは雑音帯域幅を示し、Ｒｓは信号ボーレートを示してよい。 The transmission quality quantity calculation unit 111 may convert the BER included in the BER information acquired from the control device 2 into the transmission quality quantity F by using the following equation (4). _{Equation (4) represents the transmission quality quantity F 1-4} relating to the span group (see reference numeral C2) composed of spans # 1 to # 3. In other words, the equation (4) represents the transmission quality quantity F _1-4 of the signal light transmitted from the node # 1 to the node # 4.

Here, Bn may indicate the noise bandwidth and Rs may indicate the signal baud rate.

_{Further, the transmission quality quantity F 1-3} related to the span group composed of spans # 1 and # 2 (see reference numeral C1) is the same as the transmission quality quantity F _{1-4 converted by the above equation (4).} , May be converted.

The transmission quality quantity calculation unit 111 may calculate the transmission quality quantity F of the target span based on the two transmission quality quantities converted from the BER using the following equation (5). Equation (5) shows the transmission quality amount _{F 3} of the span # 3.

_{In FIG. 8, the transmission quality quantities F 1-3} and F _1-4 in the two span groups from the same start point node # 1 to the adjacent end point nodes # 3 and # 4 are used in the target span # 3. transmission quality amount F ₃ is computed, but not limited thereto. For example, the transmission quality quantity F in the target spans # 2 and # 3 is used by using the _{transmission quality quantities F 1-2} and F _1-4 in the spans and span groups from the same start point node # 1 to the end point nodes # 2 and # 3. _2-3 may be calculated.

That is, the transmission quality quantity calculation unit 111 is an example of an acquisition unit that acquires an index relating to the first transmission performance and an index relating to the second transmission performance in the transmission path of the signal light passing through the plurality of nodes 3. good. Here, the first transmission performance may indicate the transmission performance of the signal light transmitted in the span group between the first node 3 and the nth node 3 (n is an integer of 3 or more). The second transmission performance may indicate the transmission performance of the signal light transmitted in the span or span group between the first node 3 and the node 3 of the m (natural number satisfying m <n).

Further, the transmission quality quantity calculation unit 111 relates to the transmission performance of the signal light transmitted in the span between the mth node 3 and the nth node 3 based on the indexes related to the first and second transmission performances. It may be an example of an estimation unit that estimates an index.

From these, the transmission performance can be estimated appropriately. For example, the estimation accuracy of the transmission quality quantity F in each span can be improved.

The transmission quality quantity calculation unit 111 transmits the span between the mth node 3 and the nth node 3 based on the difference between the index related to the first transmission performance and the index related to the second transmission performance. An index related to the transmission performance of the signal light may be estimated.

As a result, the transmission performance can be estimated by a simple calculation.

Indicators related to transmission performance include, for example, transmission quality quantity F, BER, EVM, OSNR, wavelength dispersion, polarization mode dispersion, PDL (polarization dependence loss), intrachannel nonlinearity, interchannel nonlinearity, mutual phase modulation, or It may be a parameter such as band narrowing.

The transmission quality amount information management unit 112 optionally stores the transmission quality amount of the target span calculated by the transmission quality amount calculation unit 111 in the transmission quality information storage unit 121.

FIG. 9 is a diagram showing an example of transmission quality quantity information 1211 in the optical communication system 100 shown in FIG. 5 in a table format.

The transmission quality amount information management unit 112 may store the transmission quality amount for each span provided in the optical communication system 100 in the transmission quality information storage unit 121 as the transmission quality amount information 1211.

In the example shown in FIG. 9, the transmission quality quantity information 1211 includes the transmission quality quantities F _{1 to} F _N-1 for spans # 1 to # N-1, respectively.

The transmission performance calculation unit 113 calculates the transmission quality amount in any of the routes via the plurality of nodes 3 based on the transmission quality amount information 1211 stored in the transmission quality information storage unit 121, for example. The "path" may include one or more wavelength paths. Hereinafter, the "path" may be referred to as a "wavelength path". The transmission performance calculation unit 113 may calculate the BER in any wavelength path passing through the plurality of nodes 3 from the calculated transmission quality quantity.

The transmission performance calculation unit 113 may calculate the transmission quality quantity F using the following equation (6). _{Equation (6) shows the transmission quality quantity F1-> N} in the wavelength path from node # 1 shown in FIG. 8 via node # N.

Further, the transmission performance calculation unit 113 may calculate the BER using the following formula (7) based on the transmission quality quantity F calculated by the above formula (6). Equation (7) shows _{BER 1-> N} in the wavelength path from node # 1 shown in FIG. 8 via node # N.

That is, the transmission performance calculation unit 113 calculates an index related to the transmission performance of the signal light transmitted in the section formed by any one or more spans based on the estimation result of the index related to the transmission performance by the transmission quality quantity calculation unit 111. It may function as an example of the calculation unit.

As a result, it is possible to improve the calculation accuracy of the transmission quality amount in the region (for example, "a section having a large number of spans from the start point node 3") where the influence of the non-linearity is large shown in FIG.

As an example, the BER threshold information management unit 115 _{reads the BER threshold value (sometimes referred to as “BER th} ”) stored by the BER threshold information storage unit 122, and inputs the read BER to the transmission possibility determination unit 114. do.

The transmission possibility determination unit 114, for example, determines whether signal light can be transmitted using any of the wavelength paths via the plurality of nodes 3 based on the BER calculated by the transmission performance calculation unit 113. do.

The transmission availability determination unit 114 may compare the BER calculated by the transmission performance calculation unit 113 with the BER threshold value read by the BER threshold information management unit 115 to determine whether transmission is possible. .. When the calculated BER is smaller than the BER threshold value (for example, when BER _{1-> N} <BER _th ), the transmission possibility determination unit 114 may determine that the signal light can be transmitted. On the other hand, if the calculated BER is equal to or greater than the BER threshold value, the transmission availability determination unit 114 may determine that the signal light cannot be transmitted.

That is, the transmission possibility determination unit 114 functions as a determination unit for determining whether or not signal light can be transmitted in a section formed by any of a plurality of spans, based on the calculation result of the index related to the transmission performance by the transmission performance calculation unit 113. You can.

Thereby, it is possible to appropriately determine whether or not the signal light can be transmitted using the wavelength path.

The update amount calculation unit 116 updates the transmission quality amount information 1211 stored in the transmission quality information storage unit 121, for example. The details of the update amount calculation unit 116 will be described later in the seventh modification. That is, the CPU 11 in the estimation device 1 of the first embodiment does not have to have the function as the update amount calculation unit 116.

[A-2] Operation Example The transmission performance estimation operation in the optical communication system 100 of the first embodiment configured as described above will be described with reference to the flowcharts (processes P1 to P9) shown in FIG.

The transmission quality quantity calculation unit 111 may measure the BER of a plurality of span groups via the control device 2 (process P1).

The transmission quality quantity calculation unit 111 may calculate the transmission quality quantity from the measured BER (process P2).

The transmission quality quantity calculation unit 111 may calculate the transmission quality quantity of the target span from the difference between the transmission quality quantity in the span group including the target span and the transmission quality quantity in the span or the span group not including the target span (). Process P3).

The transmission quality amount information management unit 112 may store the calculated transmission quality amount of each span in the transmission quality information storage unit 121 (process P4).

The transmission possibility determination unit 114 may receive a transmission possibility determination request using a certain wavelength path from the control device 2 (process P5).

The transmission performance calculation unit 113 may calculate the BER of the wavelength path related to the request from the control device 2 from the transmission quality amount of each span stored in the transmission quality information storage unit 121 (process P6).

The transmission availability determination unit 114 may determine whether the calculated BER is smaller than the BER threshold value (process P7).

When the calculated BER is smaller than the BER threshold value (Yes in the process P7), the transmission availability determination unit 114 controls that the signal light can be transmitted using the wavelength path related to the request from the control device 2. The device 2 may be notified (process P8). Then, the process may be completed.

On the other hand, when the calculated BER is equal to or higher than the BER threshold value (No in the process P7), the transmission possibility determination unit 114 cannot transmit the signal light using the wavelength path related to the request from the control device 2. May be notified to the control device 2 (process P9). Then, the process may be completed.

[A-3] Modification Example of First Embodiment Next, a modification of the first embodiment will be described.

[A-3-1] First Modification Example In the first embodiment described above, an example of estimating the transmission performance before the start of the operation of the optical communication system 100 has been described, but the estimation of the transmission performance is based on the operation of the optical communication system 100. It may be done after the start of.

FIG. 11 is a block diagram showing a configuration example of the optical communication system 101 of the first modification.

In the optical communication system 101 shown in FIG. 11, in addition to the nodes # 1 to # 5 provided at the start of operation of the optical communication system 100 shown in FIG. 5, two nodes 3 shown by thick lines (“node #”). 6 and # 7 ”). Nodes # 6 and # 7 may be nodes 3 added to the optical communication system 100 shown in FIG.

In the example shown in FIG. 11, node # 6 is connected to nodes # 3 and # 4, and node # 7 is connected to nodes # 2 and # 3.

The transmission quality quantity calculation unit 111 of the estimation device 1 may acquire wavelength path information and BER information related to the added node 3 and the span from the control device 2. Further, the transmission quality quantity calculation unit 111 may calculate the transmission quality quantity in each of the added spans (see the thick line in FIG. 11) based on the acquired wavelength path information and BER information.

In the example shown in FIG. 11, the transmission quality quantity calculation unit 111 includes the transmission quality quantity in the target span between node # 3 and node # 6 and the target span between node # 4 and node # 6. The transmission quality quantity may be calculated. Further, the transmission quality quantity calculation unit 111 calculates the transmission quality quantity in the target span between the node # 2 and the node # 7 and the transmission quality quantity in the target span between the node # 3 and the node # 7. It's okay.

According to the estimation device 1 provided in the optical communication system 101 of the first modification, it is possible to appropriately estimate the transmission quality amount for the node 3 and the span added after the operation of the optical communication system 101 is started.

[A-3-2] Second Modification Example The two transmission quality quantities used for calculating the difference by the transmission quality quantity calculation unit 111 may be determined by a preset threshold value.

FIG. 12 is a diagram showing an example of transmission performance estimation in the optical communication system 100 of the second modification.

In FIG. 12, one of a plurality of routes (see FIG. 5) composed of a plurality of nodes 3 connected in a mesh shape is shown.

In FIG. 12, the estimation device 1 and the control device 2 are not shown. Further, in FIG. 12, for the sake of explanation, the transmitter / receiver 4 (indicated as “Tx / Rx # 1 to # N”) provided in each node 3 is shown independently of each node 3. .. In other words, Tx / Rx4 shown in FIG. 12 is an example of Tx36 and Rx35 shown in FIG. In the example shown in FIG. 12, nodes # 1 to #N may be provided with Tx / Rx # 1 to # N, respectively.

Each node 3 may be communicatively connected to each other by an optical fiber transmission line. The transmission section between the nodes 3 may be referred to as a "span". In the example shown in FIG. 12, the transmission section between node # 1 and node # 2 is referred to as span # 1, and the transmission section between node # 2 and node # 3 is referred to as span # 2. Further, the transmission line between the node # 3 and the node # 4 is referred to as a span # 3, and the transmission section between the node # 4 and the node # 5 is referred to as a span # 4. Further, the transmission section between node # N-1 (not shown in FIG. 12) and node # N is referred to as span # N-1.

In the example shown in FIG. 12, the transmission quality quantity calculation unit 111 receives wavelength path information indicating a span group composed of spans # 1 and # 2 (see reference numeral D1) and signal light transmitted through the span group. The BER information indicating the BER may be acquired from the control device 2.

Further, in the example shown in FIG. 12, the transmission quality quantity calculation unit 111 includes wavelength path information indicating a span group (see reference numeral D2) composed of spans # 1 to # 3 and a signal transmitted through the span group. BER information indicating the BER of light may be acquired from the control device 2.

Further, in the example shown in FIG. 12, the transmission quality quantity calculation unit 111 includes wavelength path information indicating a span group composed of spans # 1 to # 4 (see reference numeral D3) and a signal transmitted through the span group. BER information indicating the BER of light may be acquired from the control device 2.

FIG. 13 is a diagram showing an example of the span group transmission quality quantity information 1212 in the optical communication system 100 shown in FIG. 12 in a table format.

The span group transmission quality quantity information 1212 shown in FIG. 12 is typically stored in the transmission quality information storage unit 121. In the span group transmission quality quantity information 1212, the transmission quality quantity in each span or span group acquired by the transmission quality quantity calculation unit 111 may be registered.

In the example shown in FIG. 12, F _{1 is registered for the transmission quality quantity in the span # 1, and F 1-> 2} is registered for the transmission quality quantity in the span groups # 1 and # 2. _{F1-> 3} is registered as the transmission quality quantity in the groups # 1 to # 3. _{Further, F 1-> 4} is registered in the transmission quality quantity in the span groups # 1 to # 4 _{, and F 1-> 5} is registered in the transmission quality quantity in the span groups # 1 to # 5.

For example, the transmission quality quantity calculation unit 111 increases the number of measurement spans and acquires the transmission quality quantity of the span or the span group. Here, it is assumed that the measured transmission quality quantity of the span or span group has the relationship of the following equation (8) with the _{preset transmission quality quantity threshold value Fth. When the transmission quality quantity F 1->} 5 in the span groups # 1 to # 5 is acquired, the transmission quality quantity calculation unit 111 recognizes that the transmission quality quantity F _{1-> 5} exceeds the threshold value F _th. In this case, transmission quality calculation unit 111, the difference between the transmission quality amount _{F 1-> 4} in the span group # 1 to # 4, and _{F 1-> 3} in the transmission quality weight in the span group # 1 to # 3 it is calculated and may calculate the transmission quality amount F ₄ of the span # 4.

That is, the transmission quality quantity calculation unit 111 sets an index regarding the fourth transmission performance of the signal light transmitted in the span group between the first node 3 and the node 3 of the n + 1 (n is an integer of 3 or more). Further, it may function as an example of the acquisition unit to be acquired. Then, the transmission quality quantity calculation unit 111 determines the span between the m (natural number satisfying m <n) node 3 and the nth node 3 when the index related to the fourth transmission performance is larger than a predetermined threshold value. An index relating to the transmission performance of the signal light transmitted may be estimated.

This makes it possible to efficiently estimate the amount of transmission quality in each span.

[A-3-3] Third Modification Example The two transmission quality quantities used for calculating the difference by the transmission quality quantity calculation unit 111 may be determined by a plurality of preset threshold values.

Similar to the second modification shown in FIG. 12, the transmission quality quantity calculation unit 111 obtains wavelength path information indicating each span group (see reference numerals D1 to D3) and BER of the signal light transmitted through each span group. The indicated BER information may be acquired from the control device 2.

The BER included in the BER information acquired by the transmission quality quantity calculation unit 111 is converted into the transmission quality quantity and registered in the span group transmission quality quantity information 1212 as in the second modification shown in FIG. good.

For example, the upper limit threshold value F _th1 and the lower limit threshold value F _th2 of the transmission quality quantity are determined, and the transmission quality quantity calculation unit 111 calculates the signal quality of each span in the range of _{F th1} and F _th2. It's okay. As an example, when the transmission quality quantity of the span or span group acquired by the transmission quality quantity calculation unit 111 has _{a relationship between the threshold values F th1} and F _th2 and the following equation (9), the transmission quality quantity calculation unit 111 uses the span group. # 1 and transmission quality amount _{F 1-> 4} at # 4, it may calculate the difference between the transmission quality amount _{F 1-> 3} in the span group # 1 to # 3. Further, in this case, the transmission quality quantity calculation unit 111 is the difference between the transmission quality quantity F _{1-> 5 in the span groups # 1 to # 5 and the transmission quality quantity F 1-> 4} in the span groups # 1 to # 4. May be calculated. Then, the transmission quality quantity calculation unit 111 may calculate the transmission quality quantities F ₃ and F ₄ of the spans # 3 and # 4.

That is, the transmission quality quantity calculation unit 111 spans between the m (natural number satisfying m <n) node 3 and the nth (n is an integer of 3 or more) nodes 3 when a predetermined condition is satisfied. An index related to the transmission performance of the signal light transmitted may be estimated. Here, the case where the predetermined condition is satisfied is the case where the index related to the first transmission performance is less than the predetermined first threshold value and the index related to the second transmission performance is larger than the predetermined second threshold value. It may be. The first transmission performance may be the transmission performance of the signal light transmitted through the span group between the first node 3 and the nth node 3. Further, the second transmission performance may be the transmission performance of the signal light transmitted in the span or the span group between the first node 3 and the third node 3.

This makes it possible to efficiently estimate the amount of transmission quality in each span.

[A-3-4] Fourth Modified Example The transmission quality information storage unit 121 may store a plurality of transmission quality quantities for each span.

FIG. 14 is a diagram showing an example of transmission quality quantity information 1213 in the optical communication system 100 of the fourth modification in a table format.

The transmission quality quantity calculation unit 111 may calculate a plurality of transmission quality quantities for each target span.

In FIG. 14, the transmission quality quantity calculation unit 111 has a transmission quality quantity when the number of spans passed when the signal light is transmitted is small, and a case where the number of spans passed when the signal light is transmitted is large. An example of calculating the transmission quality quantity is shown. When the number of spans is small, it may be referred to as the case of a small number of spans. Further, when the number of spans is large, it may be referred to as a case of multiple spans.

In the transmission quality quantity information 1213, the transmission quality quantity of a small span is based on the transmission quality quantity of two span groups (or one span and one span group), both of which are small spans, by the transmission quality quantity calculation unit 111. It may be the transmission quality quantity calculated by the above. The transmission quality quantity of a small span may be the transmission quality quantity measured or calculated for one span. The transmission quality quantity calculation unit 111 may determine that the span group has a small number of spans, for example, when the number of spans of the span group is equal to or less than a predetermined value. The predetermined value may be referred to as a switching threshold.

Further, in the transmission quality quantity information 1213, the multi-span transmission quality quantity is a transmission quality quantity calculated by the transmission quality quantity calculation unit 111 based on the transmission quality quantity of two span groups having at least one of the multi-spans. It may be there. The transmission quality quantity calculation unit 111 may determine that the span group has many spans, for example, when the number of spans of the span group is larger than a predetermined value.

_{In the example shown in FIG. 14, F x1 to} F _xN-1 are registered as the transmission quality quantities of the small spans in the spans # 1 to # N-1, respectively. Further, as the transmission quality of a multi-span in the span _{# 1~ # N-1, F} y1 ~F yN-1 are respectively registered.

The transmission performance calculation unit 113 may calculate the transmission quality quantity of the wavelength path related to the request from the control device 2 by using the transmission quality quantity of a small span and the transmission quality quantity of a large span. The transmission performance calculation unit 113 uses a small amount of transmission quality for each span from the start point node 3 until the number of spans reaches a predetermined value among the wavelength paths related to the request from the control device 2. The transmission quality quantity may be calculated. Further, the transmission performance calculation unit 113 uses a multi-span transmission quality quantity for each span in which the number of spans from the start point node 3 exceeds a predetermined value among the wavelength paths related to the request from the control device 2. The transmission quality quantity of

The following equation (10) shows the amount of transmission quality in the wavelength path from node # 1 to node # N when the predetermined value is set to 3.

In the above equation (10), a small-span transmission quality quantity is used for spans # 1 to # 3, and a multi-span transmission quality quantity is used for spans # 4 to # N-1. ..

That is, the transmission quality quantity calculation unit 111 sets the span between the mth node 3 and the nth node 3 with respect to the index relating to the plurality of transmission performances according to the value of n in each of the plurality of spans. An index related to the transmission performance of the transmitted signal light may be estimated. Here, n may be an integer of 3 or more, and m may be an integer satisfying m <n.

Then, the transmission performance calculation unit 113 uses any one of the indexes related to the plurality of transmission performances for each of the plurality of spans to transmit the signal light transmitted in the section formed by the plurality of spans. An index related to performance may be calculated.

As a result, the accuracy of calculating the transmission quality amount of the wavelength path can be improved.

The transmission performance estimation operation in the optical communication system 100 of the fourth modification configured as described above will be described with reference to the flowcharts (processes P11 to P21) shown in FIG.

The transmission quality quantity calculation unit 111 may measure the BER of a plurality of span groups via the control device 2 (process P11).

The transmission quality quantity calculation unit 111 may calculate the transmission quality quantity from the measured BER (process P12).

The transmission quality quantity calculation unit 111 determines the transmission quality quantity of the target span in the case of multiple spans from the difference between the transmission quality quantity in the span group including the target span and the transmission quality quantity in the span or the span group not including the target span. It may be calculated (process P13).

The transmission quality quantity calculation unit 111 determines the transmission quality quantity of the target span in the case of a small span from the difference between the transmission quality quantity in the span group including the target span and the transmission quality quantity in the span or the span group not including the target span. It may be calculated (process P14).

The transmission quality amount information management unit 112 may store the calculated transmission quality amount of each span in the transmission quality information storage unit 121 (process P15).

The transmission possibility determination unit 114 may receive a transmission possibility determination request using a certain wavelength path from the control device 2 (process P16).

The transmission quality quantity information management unit 112 stores the transmission quality in each span in the case of multiple spans or small spans stored in the transmission quality information storage unit 121 based on a predetermined value (may be referred to as a “switching threshold value”). The quantity may be read out (process P17).

The transmission performance calculation unit 113 may calculate the BER of the wavelength path related to the request from the control device 2 from the transmission quality quantity in each span in the case of a large number of spans or a small number of spans (process P18).

The transmission availability determination unit 114 may determine whether the calculated BER is smaller than the BER threshold value (process P19).

When the calculated BER is smaller than the BER threshold value (Yes in process P19), the transmission availability determination unit 114 controls that the signal light can be transmitted using the wavelength path related to the request from the control device 2. The device 2 may be notified (process P20). Then, the process may be completed.

On the other hand, when the calculated BER is equal to or higher than the BER threshold value (No in the process P19), the transmission enable / disable determination unit 114 cannot transmit the signal light using the wavelength path related to the request from the control device 2. May be notified to the control device 2 (process P21). Then, the process may be completed.

As shown in FIG. 1, the transmission quality quantity in the case of a small span may be the transmission quality quantity measured for each span.

Further, the switching threshold value described above is not limited to one, and two or more may be provided. When two or more switching thresholds are provided, the transmission quality amount information 1213 shown in FIG. 14 contains the transmission quality amount in the case of an intermediate number of spans in addition to the case of a large number of spans and a case of a small number of spans. May be registered.

For example, in the optical communication system 100 having spans # 1 to # 15, the case where the two switching thresholds are 5 and 10 will be described. In this case, the transmission performance calculation unit 113 calculates the transmission quality quantity of the wavelength path for the spans # 1 to # 5 by using the transmission quality quantity calculated by the two span groups having the number of spans of 4 or less. It's okay. Further, the transmission performance calculation unit 113 may calculate the transmission quality quantity of the wavelength path for the spans # 6 to # 10 by using the transmission quality quantity calculated by the two span groups having the number of spans of 9 or less. Further, the transmission performance calculation unit 113 may calculate the transmission quality quantity of the wavelength path for the spans # 11 to # 15 by using the transmission quality quantity calculated by the two span groups having the number of spans of 14 or less.

[A-3-5] Fifth Modification Example The transmission quality quantity information 1211 shown in FIG. 9 or the transmission quality quantity information 1213 shown in FIG. 14 may be updated after the operation of the optical communication system 100 is started.

_{The following equation (11) shows the updated transmission quality quantity F x} ′ in the span # x when the wavelength path composed of the nodes # 1 to # N is communicated and the transmission quality quantity is actually measured.

In the above equation (11), _{F1-> N_measured} may be the amount of transmission quality actually measured at the nodes # 1 to #N. Further, α _x may be an update coefficient in span # x.

One of the following two may be used for the update coefficient.
Update coefficient = total of applicable span loss / span loss Update coefficient = reciprocal of transmission quality quantity of applicable span loss / reciprocal of transmission quality quantity of path

Further, after the operation of the optical communication system 100, the transmission quality quantity of each span other than the target span may be updated in the same manner as described above.

That is, the transmission quality information storage unit 121 is a signal transmitted through a span group between the first node 3 acquired by the transmission quality quantity calculation unit 111 and the nth node 3 (n is an integer of 3 or more). It may function as an example of a first storage unit that stores an index relating to the first transmission performance of light. Further, the transmission quality information storage unit 121 is a signal light transmitted over a span between the m (natural number of m <n) of the m (natural number of m <n) estimated by the transmission quality quantity calculation unit 111 and the nth node 3. It may function as an example of a second storage unit that stores an index related to the third transmission performance.

Then, the update amount calculation unit 116 may function as an example of an update unit that updates the stored third transmission performance index. The update of the index related to the third transmission performance includes the measured value of the index related to the transmission performance of the signal light transmitted in the span group between the first node 3 and the nth node 3 and the stored first index. It may be performed based on the index regarding the transmission performance and the stored index regarding the third transmission performance.

As a result, the transmission quality amount of the wavelength path can be appropriately calculated according to the change in the system environment that occurs after the start of operation of the optical communication system 100.

[A-3-6] Sixth Modification Example The transmission quality amount of the wavelength path by the transmission performance calculation unit 113 may be calculated in consideration of the performance of the signal light generated in the transmitter / receiver of the node 3.

As one example, the transmission quality amount of the wavelength path calculated by the transmission performance calculation unit 113 is calculated by the deterioration amount F _{Tx of the signal light generated in Rx35 and Tx36 shown in FIG. 6 or Tx / Rx4 shown in FIG. / Rx} may be considered. The following equation (12) represents the transmission quality quantity _{F1-> N} of the wavelength path composed of the nodes # 1 to #N.

F _{Tx / Rx} may be, for example, the amount of deterioration of the signal light generated when Tx36 and Rx35 are directly connected.

As another example, when the transmission quality quantity is OSNR, the transmission quality quantity F1- _{> N} of the wavelength path composed of the nodes # 1 to #N is expressed by the following equation (13). It's okay.

Here, _Pase represents the amount of ASE (Amplified Spontaneous Emission) noise. Further, P _NLI represents a non-linear noise amount. Further, κ and η are parameters determined by the performance of TRPN (Transponder) in BtoB connection (in other words, “0 km transmission”). In addition, "BtoB" is an abbreviation for "Back To Back".

The transmission quality quantity in span # N-1 may be calculated by the following equation (14).

Then, the transmission performance calculation unit 113 may calculate the transmission quality quantity of the wavelength path composed of the nodes # 1 to # N by using the following equation (15) based on the transmission quality quantity in each span.

That is, the transmission performance calculation unit 113 uses the amount of deterioration of the signal light at each of the start point node 3 and the end point node 3 in the section formed by any of the plurality of spans to obtain an index regarding the transmission performance of the transmitted signal light. It may be calculated.

Thereby, the transmission quality amount of the wavelength path can be appropriately calculated in consideration of the deterioration amount of the signal light generated in Tx / Rx4.

[A-3-7] 7th Modification Example The transmission quality amount of the wavelength path by the transmission performance calculation unit 113 may be calculated in consideration of the noise amount generated in the signal light at the node 3.

FIG. 16 is a block diagram showing a configuration example of the optical communication system 102 of the seventh modification.

FIG. 16 shows any two directly connected nodes 3 (eg, nodes # 1 and # 2) of the optical communication system 100 shown in FIG.

As shown in FIG. 16, each node 3 includes, exemplary, two branching portions 321, two insertion portions 322, two input amplifiers 33, two output amplifiers 34, and Tx / Rx4. Further, each node 3 includes, for example, a demultiplexer 51, a demultiplexer 52, two demultiplexer input amplifiers 53, and two demultiplexer output amplifiers 54. Note that in FIG. 16, the node control unit 31 shown in FIG. 6 is not shown.

The branch portion 321 and the insertion portion 322 are exemplary examples of the optical branch insertion portion 32 shown in FIG.

The duplexer input amplifier 53, exemplary, amplifies the signal light input from the branch portion 321.

Illustratively, the demultiplexer 51 demultiplexes the signal light input from the demultiplexer input amplifier 53 for each wavelength, and divides the demultiplexed signal light into Tx / Rx4, for example, a plurality of signal lights shown in FIG. Input to each of Rx35.

When the signal light received in Tx / Rx4 is coherent signal light, a splitter that distributes the power of the signal light to each Rx35 in Tx / Rx4 may be provided instead of the demultiplexer 51. ..

The combiner 52 exemplifies, for example, combining signal light input from each of Tx / Rx4, for example, a plurality of Tx36s shown in FIG. 6, and the combined signal light is transmitted to the combiner output amplifier 54. input.

The combiner output amplifier 54 typically inputs the signal light input from the combiner 52 to the insertion unit 322.

In the two demultiplexer input amplifiers 53 and the two combiner output amplifiers 54, a noise amount may be generated in the signal light. The demultiplexer 51, the demultiplexer 52, the two demultiplexer input amplifiers 53, and the two demultiplexer output amplifiers 54 may be referred to as an Add / Drop unit.

Therefore, the transmission performance calculation unit 113 may calculate the transmission quality quantity of the wavelength path by using the following equation (16). _{In the formula (16), the deterioration amount FTx / Rx of} the signal light generated in the above-mentioned Tx / Rx4 in the sixth embodiment is also taken into consideration.

Transmission quality amount calculated by the transmission performance calculation unit 113, a transmission quality amount _{F i} at each span, the deterioration amount _{F Tx / Rx} of the signal light generated in the Tx / Rx4, generated in the signal light in the Add / Drop unit The amount of noise to be generated may be divided into _{F Add / Drop.}

That is, the transmission performance calculation unit 113 relates to the transmission performance of the signal light to be transmitted by using the amount of noise generated in the signal light at each of the start point node 3 and the end point node 3 in the section formed by any one or more spans. The index may be calculated.

Thereby, the transmission quality amount of the wavelength path can be appropriately calculated in consideration of the noise amount generated in the signal light in the Add / Drop unit.

[B] Second Embodiment In the first embodiment, in a state where one of a plurality of paths composed of a plurality of nodes 3 connected in a mesh shape is given, each wavelength in the one path is given. The method of obtaining the transmission quality quantity of the target span was explained by measuring the transmission quality quantity of the path.

However, for example, in the case of newly constructing a large-scale network or a network in which a plurality of nodes 3 are connected in a complicated mesh shape, it may be difficult to determine an appropriate route from a plurality of routes. be.

For example, when a route that passes through a specific node 3 a plurality of times is selected as the route to be measured, the number of times of measuring the transmission quality amount of the wavelength path increases and the number of times of controlling the node 3 also increases, so that the measurement time And the equipment load may increase. Further, when a path having a small number of spans of the wavelength path (for example, a specific node 3 is not included) is selected as the path to be measured, the estimation accuracy of the transmission quality amount of the target span may be lowered.

Therefore, in the second embodiment, a method of determining a route to be measured from a plurality of routes composed of a plurality of nodes 3 will be mainly described in a network topology in which a plurality of nodes 3 are connected in a mesh shape. ..

[B-1] System Configuration Example FIG. 17 is a block diagram showing a configuration example of the optical communication system 100A of the second embodiment.

As shown in FIG. 17, the optical communication system 100A includes, exemplary, an estimation device 1A, a control device 2, and a plurality of (five in the illustrated example) nodes 3A shown as nodes A to E. .. The function as the estimation device 1A may be provided in the control device 2.

Unless otherwise specified, the functions and configurations of the estimation device 1A, the control device 2, and the node 3A, and their connection relationships are the estimation device 1, the control device 2, and the node 3 according to the first embodiment, respectively. , And these connection relationships may be similar.

FIG. 18 is a block diagram showing a configuration example of a node 3A in the optical communication system 100A shown in FIG. Examples of the node 3A include a reconfigurable optical branch insertion device such as a ROADM (Reconfiguration Optical Add-Drop Multiplexer). ROADM may have functions such as CD (Color-less, Direction-less) or CDC (Color-less, Direction-less, Contention-less).

As shown in FIG. 18, the node 3A is exemplified by a node control unit 31A, an optical branch insertion unit 32A and 32B, an input amplifier 33A and 33B, an output amplifier 34A and 34B, a plurality of reception units 35, and a plurality of transmissions. A section 36 and a light accommodating section 39 are provided.

The receiving unit (“Rx” in the example of FIG. 18) 35 and the transmitting unit (“Tx” in the example of FIG. 18) 36 may be the same as the Rx35 and Tx36 according to the first embodiment shown in FIG. 6, respectively. .. Further, the reference numerals 32A to 34A and the reference numerals 32B to 34B have a configuration in which two systems of an optical branch insertion unit 32, an input amplifier 33, and an output amplifier 34 according to the first embodiment shown in FIG. 6 are provided, for example, a signal. It corresponds to the configuration provided for each different transmission direction of light.

The node control unit 31A typically controls the optical branch insertion units 32A and 32B, the input amplifiers 33A and 33B, and the output amplifiers 34A and 34B. Further, the node control unit 31A is communicably connected to the control device 2 like the node control unit 31 of the first embodiment, causes Rx35 to measure the BER of the wavelength path, and controls information including the measurement result of the BER. The device 2 may be notified.

The optical accommodating portion 39 is communicably connected to the optical branch insertion portions 32A and 32B, Rx35, and Tx36. For example, the optical accommodating unit 39 separates the signal light input from the optical branch insertion units 32A and 32B and outputs the signal light to the Rx35, and multiplexes the signal light input from the Tx36 to the optical branch insertion units 32A and 32B. Output.

In the node 3 according to the first embodiment shown in FIG. 6, the block between the optical branch insertion unit 32 and the Rx35 and Tx36 may be replaced with the optical accommodating unit 39. Alternatively, the light accommodating portion 39 shown in FIG. 18 may be divided into a separating portion for Rx35 and a multiplexing portion for Tx36.

FIG. 19 is a block diagram showing a configuration example of the estimation device 1A in the optical communication system 100A shown in FIG.

The estimation device 1A is an example of an optical transmission performance estimation device, and includes a CPU 11A and a memory 12A as an example, as shown in FIG.

The CPU 11A has the same functions as the CPU 11 according to the first embodiment shown in FIG. 7, and also includes a routing unit 117 as an example, as shown in FIG.

The routing unit 117 is composed of a plurality of nodes 3A based on the topology information (may be referred to as “network topology information”) of a network in which the plurality of nodes 3A are connected in a mesh shape. Determine the route to be measured from the route. The "path" is an example of a signal light transmission path passing through a plurality of nodes.

For example, the route determination unit 117 may select a route that passes through a transmission line in the network with a single stroke as the route to be measured. As shown in FIG. 8 and the like, the measurement target route is, for example, a transmission quality quantity measurement target by the transmission quality quantity calculation unit 111 and the like according to the first embodiment.

The topology information is an example of information indicating the connection relationship of the node 3A and the like, and may include, for example, information indicating which node 3A the node 3A is connected to.

In the second embodiment, it is assumed that the topology information includes two nodes 3A having an odd number of roads. The number of directions may mean the number of transmission lines (which may be referred to as "links") connected to the node 3A. The two nodes 3A having an odd number of directions (nodes D and E in the example of FIG. 17) are the start point and end point nodes 3A of the one-stroke route selected by the route determination unit 117, respectively.

Topology information may be generated or managed, for example, in node 3A or controller 2. The routing unit 117 may acquire the topology information from the node 3A or the control device 2 via the control device 2, or may acquire the topology information input by the operator via a management terminal or the like (not shown). ..

The controller 2 or the node 3A may have network management software such as an SDN (Software Defined Networking) controller or an NMS (Network Management System) for generating or managing topology information. Alternatively, the node 3A may be equipped with a function corresponding to OSPF (Open Shortest Path First) or the like.

The memory 12A stores the same information as the memory 12 according to the first embodiment shown in FIG. 7, and as shown in FIG. 19, exemplary, the routing topology information 123 (hereinafter, simply “topology”). Information 123 ”may be written as“ Information 123 ”).

For example, when the routing unit 117 acquires the topology information via the control device 2, the routing information may be rewritten and stored in the memory 12A as the routing topology information 123.

FIG. 20 is a diagram showing an example of topology information 123 for routing in the optical communication system 100A shown in FIG.

For example, for each node 3A included in the acquired topology information, the routing unit 117 has (N + 1) / 2 nodes when the number of directions N (N is an integer) of the node 3A is odd, and N is an even number. In this case, the topology information is rewritten so that it is separated into N / 2 nodes.

Hereinafter, the separated nodes will be referred to as nodes 3B in order to distinguish them from the nodes 3A shown in FIG. Further, when representing a specific node 3B, the notation shown in FIG. 20 is used to indicate "node B1" and "node C2". Node 3B may be positioned as a temporary (or temporary, virtual) node for routing in relation to the actual node 3A.

In the example of FIG. 20, for convenience, the topology information 123 will be described by a block diagram showing the connection relationship between the nodes 3A. It may be stored as information 123.

In the topology information 123, as illustrated in FIG. 20, the links between the nodes 3A may be replaced with a plurality of links between the nodes 3B. For example, in the topology information 123, the link between the nodes BC is the link between the nodes B1-C1, the link between the nodes B1-C2, the link between the nodes B2-C1, and the link between the nodes B2-C2. Will be replaced.

The link between the nodes 3B may be regarded as a set of edges e in consideration of the direction, as illustrated in FIG. For example, the link between nodes B1-C2 may include an edge e from node B1 to node C2 and an edge e from node C2 to node B1. The edge e may be a variable having a value of "0" or "1". For example, the edge e is set to "1" when adopted as a route and "0" when not adopted. May be done.

Hereinafter, when the edge e from a certain node src (Source) to a certain node dst (Destination) is represented, the sign of "src" and "dst" is added after the sign "e" of the edge. For example, the node edge edges e from B1 to Node C2 _{e B1C2,} denoted from node C2 edge e of the node B1 and edge _{e C2B1.}

Here, as illustrated in FIG. 20, each of the nodes 3B may be associated with a passing order h. The passing order h may be an integer variable, and the order in which the signal light passes through the node 3B in the path may be set.

Hereinafter, when the passage order h of the specific node 3B is represented, the code of the node 3B is added after the reference code “h” of the passage order. For example, the passing order of the node B1 is expressed _{as h B1} , and the passing order of the node _{F2 is expressed as h F2.} The passage order h may be included in the topology information 123, or may be managed as information different from the topology information 123, for example, in association with the node 3B.

The route determination unit 117 may calculate the passage order h related to each node 3B so that the total value of the passage order h related to each node 3B is minimized. For example, the route determination unit 117 may calculate the passage order h by using a mathematical programming method based on the objective function that minimizes the total value of the passage order h related to each node 3B and the constraint conditions thereof.

In the example of FIG. 20, the objective function is h _A + h _B1 + h _B2 + h _C1 + h _C2 + h _D1 + h _D2 + h _E1 + h _E2 . The routing unit 117 obtains the passage order h of each of the nodes 3A such that the objective function is minimized under the following constraints 1 to 3.

Hereinafter, the constraint conditions 1 to 3 will be described with reference to FIGS. 22 to 24.

(Constraint 1)
The route passes through each link between nodes 3A only once.

For example, for each link between the nodes 3A, only one of the plurality of edges e in the link e becomes "1". As an example, as shown in FIG. 22, in the case of a link between nodes B and C, the conditional expression of _{e B1C1} + e _C1B1 + e _B1C2 + e _C2B1 + e _B2C1 + e _C1B2 + e _B2C2 + e _{C2B2 = 1 is satisfied.}

As described above, under the constraint condition 1, in the link in which the edge e selected as the route exists even once, the other edge e in the link is not selected. For example, for the link between nodes _BC , if the edge e B1C2 from node B1 to node C2 is selected, the other remaining edges e between nodes BC are not selected. This avoids the inclusion of redundant spans in the path.

(Constraint 2)
The number of input / output edges of the node 3B is limited by the type of the node 3B.

Examples of the type of node 3B include "start point node", "intermediate node", and "end point node". For example, in the start point node 3A which is the start point of the route, the start point node 3B is assigned to any node 3B in the node 3A, and in the end point node 3A which is the end point of the route, any node 3B in the node 3A is assigned. The end point node 3B is assigned to. An intermediate node 3B is assigned to a node 3B that is not selected as a start point or end point node 3B in the start point or end point node 3A, and each node 3B in the intermediate node 3A that serves as a relay point of the route.

In the start point node 3B, the total of the edges e exiting the start point node 3B is “1”, and the total of the edges e entering the start point node 3B is “0”. That is, in the start point node 3B, there is one edge e coming out of the start point node 3B and zero edge e toward the start point node 3B.

In the intermediate node 3B, the total of the edges e exiting the intermediate node 3B is “1”, and the total of the edges e entering the intermediate node 3B is “1”. That is, in the intermediate node 3B, there is one edge e coming out of the intermediate node 3B and one edge e toward the intermediate node 3B.

At the end point node 3B, the total of the edges e exiting the end point node 3B is “0”, and the total of the edges e entering the end point node 3B is “1”. That is, in the end point node 3B, there are 0 edges e coming out of the end point node 3B and one edge e toward the end point node 3B.

As an example, as shown in FIG. 23, when the node D1 is the starting point node 3B, the total of the edges e exiting from the node D1 is e _D1B1 + e _D1B2 + e _D1C1 + e _D1C2 + e _D1E1 + e _D1E2 = 1. Further, the total of the edges e entering the node D1 is e _B1D1 + e _B2D1 + e _C1D1 + e _C2D1 + e _E1D1 + e _E2D1 = 0.

Further, for example, when the node A is the intermediate node 3B, the total of the edges e exiting from the node A is e _AB1 + e _AB2 + e _AC1 + e _AC2 = 1. Further, the total number of edges e entering the node A is e _B1A + e _B2A + e _C1A + e _C2A = 1.

Further, for example, when the node E2 is the end point node 3B, the total of the edges e exiting from the node E2 is e _E2B1 + e _E2B2 + e _E2C1 + e _E2C2 + e _E2D1 + e _E2D2 = 0. Further, the total of the edges e entering the node E2 is e _B1E2 + e _B2E2 + e _C1E2 + e _C2E2 + e _D1E2 + e _D2E2 = 1.

As described above, in the constraint condition 2, the number of edges e adopted in the route between the node 3B and the adjacent node 3B of the node 3B is limited according to the type of the node 3B. This avoids the inclusion of redundant spans in the path. The adjacent node 3B may mean another node 3B having a link with a certain node 3B. For example, another node communicably connected to the certain node 3B by an optical fiber transmission line. It may be 3B.

(Constraint 3)
The value of the passing order h of the nodes 3B at both ends of the selected edge e is h _src <h _dst .

For example, as shown in FIG. 24, when the edge e _B1A from the node B1 to the node A is selected, the passing order h _A and h _B1 of the nodes A and B1 is −M × (1-e _B1A ) + h _B1. -H _A <0 is determined to satisfy the conditional expression. It is assumed that M is a sufficiently large number.

In the conditional expression, when the edge _{e B1A} is selected, the edge _{e B1A} = 1 _{becomes, -M × (1-e B1A} ) = 0 , and _therefore, h B1 _-h A <as 0 hold _{(h B1} <H _B1 and h _A are determined so as to satisfy _{h A).}

If the edge e _B1A is not selected, −M × (1-e _B1A ) has a minus sign and becomes a large value, so that the above conditional expression is an invalid condition for _{h B1} and h _A.

As described above, the constraint condition 3 gives a constraint on the passing order h, unlike the constraint conditions 1 and 2 that give a constraint on the node 3B and the edge e. For example, since the above conditional expression is a valid conditional expression for the passing order h of the nodes 3B at both ends of the selected edge e among all the nodes 3B in the topology information 123, the passing order h is appropriately determined. be able to.

The route determination unit 117 calculates the passage order h of each node 3B in the topology information 123 by using the mathematical programming method based on the above objective function and the constraints 1 to 3, and determines the route. can do.

Next, an example of the route determination result will be described with reference to FIG. 25.

As illustrated in FIG. 25, the route determination unit 117 routes a route that passes through all spans, starting from node D and going around nodes B → A → C → E → D → C → B → E with a single stroke. Can be decided.

When the route calculation is completed, the route determination unit 117 may notify the control device 2 of the obtained route information, and cause the control device 2 to set the optical cross-connect for each node 3A. When the completion of the optical cross-connect setting by the control device 2 is detected, the route determination unit 117 may instruct the transmission quality quantity calculation unit 111 to measure the transmission quality quantity using the route information. The measurement of the transmission quality quantity may be carried out, for example, by the method according to the first embodiment described above.

The route determination unit 117 may detect the completion of the optical cross-connect setting, for example, by receiving a completion notification from the control device 2. Alternatively, when the routing unit 117 detects that the signal light has reached the end point node 3A (for example, node E) from the start point node 3A (for example, node D) via the relay node 3A, the optical cross-connect setting is performed. Completion may be detected.

Thereby, the transmission quality quantity of each transmission line of the entire network can be measured by a series of measurement processes. Further, according to the constraints 1 to 3, a route that passes through all the spans in the network formed by the plurality of nodes 3A and does not pass through the overlapping spans can be selected as the route to be measured.

As described above, the routing unit 117 sets the transmission path of the signal light passing through all the spans in the network formed by the plurality of nodes 3A as an index related to the first transmission performance and an index related to the second transmission performance. This is an example of a determination unit that determines the transmission path to be acquired.

[B-2] Operation Example The routing operation and the transmission performance estimation operation in the optical communication system 100A of the second embodiment configured as described above are performed according to the flowcharts (processes P31 to P34 and P1 to P4) shown in FIG. explain.

The routing unit 117 may acquire network topology information via the control device 2 (process P31).

The route determination unit 117 may determine the route based on the acquired topology information (process P32). The route is determined by converting the topology information to the topology information 123 related to the node 3B, setting the target function based on the topology information 123, setting the constraints 1 to 3, and determining the route order h based on the mathematical programming method. May be included.

The route determination unit 117 may determine whether or not there is a route for which the transmission quality quantity has not been measured (process P33). When there is an unmeasured route (Yes in process P33), the route determination unit 117 may set an optical cross-connect to the target node 3A of the route via the control device 2 (process P34).

When the setting of the optical cross-connect is completed, the process may shift to P1. The processes P1 to P4 may be the same as the processes P1 to P4 illustrated in FIG. For example, in the processes P1 to P4, the transmission quality amount calculation unit 111 measures the BER of a plurality of span groups, calculates the transmission quality amount from the measured BER, calculates the transmission quality amount of the target span, and calculates each of them. The transmission quality quantity of the span may be stored in the memory 12A. When the process P4 is completed, the process may shift to P33.

On the other hand, in the process P33, when there is no unmeasured path (No in the process P33), the process may be terminated. If No in the process P33, at least one of the processes P5 to P9 illustrated in FIG. 10 may be executed.

[B-3] Modification Example of the Second Embodiment Next, a modification of the second embodiment will be described.

In the second embodiment described above, the method of determining the route via all the links in the optical communication system 100A has been described, but there may be links that are not routed depending on the network scale.

For example, in the second embodiment, when extracting a route that is written in one stroke, if the network scale is large, the total length of the route becomes long, and the transmission quality quantity at the node 3A cannot be measured correctly. There is.

Therefore, when there is a route that is a one-stroke solution, the route determination unit 117 fixes the start point node 3A and the end point node 3A of the route, reduces the links, divides the route into a small topology, and divides the route into a small topology. You may determine the route for your network topology. In other words, the routing unit 117 transmits a plurality of transmission paths of signal light passing through all the spans in the network, in which the start point node and the end point node of the wavelength path are common and the spans passing through the transmission paths are different from each other. It may be separated into routes. As a result, the route can be shortened, and the amount of transmission quality at the node 3A can be measured correctly.

The route determination unit 117 may determine that the route is shortened, for example, when the number of spans in the obtained route is larger than a predetermined threshold value.

FIG. 27 is a diagram showing an example of the route determined in the modified example of the second embodiment.

As an example, as shown by the solid line in FIG. 27, in the case of the topology in which the links between the nodes BC, BE, and CE are deleted, the routing unit 117 has the nodes D → B → A → C. The route of → D → E can be obtained, and the total length of the route can be shortened.

Further, as shown by the broken line in FIG. 27, in the case of the topology in which the links between the nodes BA, AC, CD, BE, and DE are deleted, the routing unit 117 , Nodes D → B → C → E can be found, and the total length of the route can be shortened.

Further, as shown by the alternate long and short dash line in FIG. 27, in the case of the topology in which the links between the nodes BA, BC, AC, CD, CE, and DE are deleted. , The route determination unit 117 can obtain the route of the nodes D → B → E, and can shorten the total length of the route.

The route determination unit 117 instructs the control device 2 to set the cross-connect of the node 3A in order for each of the plurality of routes divided into the small-scale network topology, and instructs the transmission quality quantity calculation unit 111. The transmission quality quantity of each span may be calculated.

The process according to the modified example of the second embodiment described above may be executed in the process P32 of FIG. 26, and the plurality of routes divided into the small-scale network topology are measured one by one in the processes P33 and P34. It may be selected as the route. In other words, the transmission quality quantity calculation unit 111 may acquire and estimate the transmission quality quantity for each of the plurality of separated transmission paths by the same method as in the first embodiment.

[C] Other disclosed techniques are not limited to the above-described embodiments, and can be variously modified and implemented without departing from the spirit of each embodiment. Each configuration and each process of each embodiment can be selected as necessary, or may be combined as appropriate.

For example, the above-mentioned fifth modification and sixth modification may be combined. That is, the transmission quality amount of the wavelength path is calculated by using the transmission quality amount in each span updated by the fifth modification and the deterioration amount of the signal light generated at Tx / Rx4 of each node in the sixth modification. May be done.

[D] Additional Notes The following additional notes will be further disclosed with respect to the above embodiments and modifications.

(Appendix 1)
An index relating to the first transmission performance of signal light transmitted in a span group between a first node and an nth node (n is an integer of 3 or more) in a signal light transmission path passing through a plurality of nodes. And an index relating to the second transmission performance of the signal light transmitted through the span or span group between the first node and the node of the m (natural number satisfying m <n). When,
An estimation unit that estimates an index related to the transmission performance of the signal light transmitted in the span between the mth node and the nth node based on the first and second transmission performance indexes.
Optical transmission performance estimation device equipped with.

(Appendix 2)
The estimation unit performs the estimation based on the difference between the index relating to the first transmission performance and the index relating to the second transmission performance.
The optical transmission performance estimation device according to Appendix 1.

(Appendix 3)
The estimation unit makes the estimation for each of the plurality of spans.
The optical transmission performance estimation according to Appendix 1 or 2, further comprising a calculation unit for calculating an index relating to the transmission performance of the signal light transmitted in a section formed by any one of the plurality of spans based on the estimation result. Device.

(Appendix 4)
The optical transmission performance estimation device according to Appendix 3, further comprising a determination unit for determining whether or not the signal light can be transmitted in the section based on the calculation result.

(Appendix 5)
The estimation unit makes the estimation for the plurality of indexes related to the transmission performance according to the value of n in each of the plurality of spans.
The calculation unit performs the calculation for each of the plurality of spans using any one of the plurality of indicators relating to the transmission performance.
The optical transmission performance estimation device according to Appendix 3 or 4.

(Appendix 6)
The calculation unit performs the calculation using the deterioration amount of the signal light at each of the start point node and the end point node in the section.
The optical transmission performance estimation device according to any one of Appendix 3 to 5.

(Appendix 7)
The calculation unit performs the calculation using the amount of noise generated in the signal light at each of the start point node and the end point node in the section.
The optical transmission performance estimation device according to any one of Supplementary note 3 to 6.

(Appendix 8)
A first storage unit that stores an index related to the first transmission performance acquired by the acquisition unit, and a first storage unit.
A second storage unit that stores an index relating to a third transmission performance of the signal light transmitted through the span between the mth node and the nth node acquired by the acquisition unit, and a second storage unit.
An actually measured value of an index relating to the transmission performance of the signal light transmitted through the span group between the first node and the nth node, and an index relating to the first transmission performance stored by the first storage unit. And an update unit that updates the index related to the third transmission performance stored in the second storage unit based on the index related to the third transmission performance stored by the second storage unit.
The optical transmission performance estimation device according to any one of Items 1 to 7, further comprising.

(Appendix 9)
The acquisition unit further acquires an index relating to a fourth transmission performance of the signal light transmitted in the span group between the first node and the n + 1 node.
The estimation unit makes the estimation when the index related to the fourth transmission performance is larger than a predetermined threshold value.
The optical transmission performance estimation device according to any one of Items 1 to 8.

(Appendix 10)
The estimation unit performs the estimation when the index related to the first transmission performance is less than a predetermined first threshold value and the index related to the second transmission performance is larger than a predetermined second threshold value. ,
The optical transmission performance estimation device according to any one of Items 1 to 8.

(Appendix 11)
In the signal light transmission path connected via a plurality of nodes, the first transmission of the signal light transmitted through the span group between the first node and the nth (n is an integer of 3 or more) nodes. Obtain an index related to performance and an index related to the second transmission performance of the signal light transmitted in a span or a group of spans between the first node and a node of the m (natural number satisfying m <n). death,
Based on the first and second transmission performance indexes, the index regarding the transmission performance of the signal light transmitted in the span between the mth node and the nth node is estimated.
Optical transmission performance estimation method.

(Appendix 12)
The estimation is performed based on the difference between the index relating to the first transmission performance and the index relating to the second transmission performance.
The optical transmission performance estimation method according to Appendix 11.

(Appendix 13)
The above estimation is made for each of the plurality of spans.
Based on the estimation result, an index relating to the transmission performance of the signal light transmitted in the section formed by any one of the plurality of spans is calculated.
The optical transmission performance estimation method according to Appendix 11 or 12, further comprising.

(Appendix 14)
Based on the calculation result, it is determined whether or not the signal light can be transmitted in the section.
The optical transmission performance estimation method according to Appendix 13.

(Appendix 15)
In each of the plurality of spans, the estimation is performed for the plurality of indexes related to the transmission performance according to the value of n.
For each of the plurality of spans, the calculation is performed using any one of the plurality of indicators relating to the transmission performance.
The optical transmission performance estimation method according to Appendix 13 or 14.

(Appendix 16)
The calculation is performed using the amount of deterioration of the signal light at each of the start point node and the end point node in the section.
The optical transmission performance estimation method according to any one of Appendix 13 to 15.

(Appendix 17)
The calculation is performed using the amount of noise generated in the signal light at each of the start point node and the end point node in the section.
The optical transmission performance estimation method according to any one of Appendix 13 to 16.

(Appendix 18)
The acquired index related to the first transmission performance is stored, and the index is stored.
The index regarding the third transmission performance of the signal light transmitted in the span between the acquired mth node and the nth node is stored.
An actually measured value of an index relating to the transmission performance of the signal light transmitted through the span group between the first node and the nth node, the stored index relating to the first transmission performance, and the stored index. The memorized third transmission performance index is updated based on the third transmission performance index.
The optical transmission performance estimation method according to any one of Appendix 11 to 17, further comprising.

(Appendix 19)
Further, an index relating to the fourth transmission performance of the signal light transmitted through the span group between the first node and the n + 1 node is obtained.
When the index relating to the fourth transmission performance is larger than a predetermined threshold value, the estimation is performed.
The optical transmission performance estimation method according to any one of Supplementary Notes 11 to 18.

(Appendix 20)
The estimation is performed when the index related to the first transmission performance is less than a predetermined first threshold value and the index related to the second transmission performance is larger than a predetermined second threshold value.
The optical transmission performance estimation method according to any one of Supplementary Notes 11 to 18.

(Appendix 21)
The acquisition unit acquires the index related to the first transmission performance and the index related to the second transmission performance of the signal light transmission path passing through all the spans in the network formed by the plurality of nodes. Determining part that determines the transmission path,
The optical transmission performance estimation device according to any one of Items 1 to 10, further comprising the above.

(Appendix 22)
When the number of spans included in the transmission path of the signal light passing through all the spans in the network is larger than a predetermined threshold value, the determination unit shares the transmission path with the start point node and the end point node of the transmission path. However, it is separated into a plurality of transmission paths having different spans.
The acquisition unit and the estimation unit perform the acquisition and the estimation for each of the plurality of separated transmission paths.
The optical transmission performance estimation device according to Appendix 21.

(Appendix 23)
The transmission path of the signal light passing through all the spans in the network formed by the plurality of nodes is set as the transmission path for acquiring the index related to the first transmission performance and the index related to the second transmission performance. decide,
The optical transmission performance estimation method according to any one of Supplementary note 11 to 20.

(Appendix 24)
In the determination, when the number of spans included in the transmission path of signal light passing through all the spans in the network is larger than a predetermined threshold value, the transmission path is shared by the start point node and the end point node of the transmission path. And, it is separated into a plurality of transmission paths with different spans.
The acquisition and the estimation are performed for each of the plurality of separated transmission paths.
The optical transmission performance estimation method according to Appendix 23.

100, 100a, 100A: Optical communication system 101, 102: Optical communication system 1, 1A: Estimator 11, 11A: CPU
111: Transmission quality amount calculation unit 112: Transmission quality amount information management unit 113: Transmission performance calculation unit 114: Transmission availability judgment unit 115: BER threshold information management unit 116: Update amount calculation unit 117: Route determination unit 12, 12A: Memory 121: Transmission quality information storage unit 1211, 1213: Transmission quality amount information 1212: Span group transmission quality amount information 122: BER threshold information storage unit 123: Route determination topology information 2: Control devices 3, 3a, 3A, 3B: Node 31, 31A: Node control unit 32, 32A, 32B: Optical branch insertion unit 321: Branch unit 322: Insert unit 33, 33A, 33B: Input amplifier 34, 34A, 34B: Output amplifier 35: Rx
36: Tx
37, 37A, 37B: Optical fiber 38, 38A, 38B: Optical fiber 39: Optical accommodating portion 4, 4a: Tx / Rx
51: Demultiplexer 52: Demultiplexer 53: Demultiplexer input amplifier 54: Demultiplexer output amplifier

Claims (11)

An index relating to the first transmission performance of signal light transmitted in a span group between a first node and an nth node (n is an integer of 3 or more) in a signal light transmission path passing through a plurality of nodes. And an index relating to the second transmission performance of the signal light transmitted through the span or span group between the first node and the node of the m (natural number satisfying m <n). When,
An estimation unit that estimates an index related to the transmission performance of the signal light transmitted in the span between the mth node and the nth node based on the first and second transmission performance indexes.
A first storage unit that stores an index related to the first transmission performance acquired by the acquisition unit, and a first storage unit.
A second storage unit that stores an index relating to a third transmission performance of the signal light transmitted in the span between the mth node and the nth node estimated by the estimation unit, and a second storage unit.
An actually measured value of an index relating to the transmission performance of the signal light transmitted through the span group between the first node and the nth node, and an index relating to the first transmission performance stored by the first storage unit. And an update unit that updates the index related to the third transmission performance stored in the second storage unit based on the index related to the third transmission performance stored by the second storage unit.
Optical transmission performance estimation device equipped with. The estimation unit performs the estimation based on the difference between the index relating to the first transmission performance and the index relating to the second transmission performance.
The optical transmission performance estimation device according to claim 1. The estimation unit makes the estimation for each of the plurality of spans.
The optical transmission according to claim 1 or 2, further comprising a calculation unit for calculating an index relating to the transmission performance of the signal light transmitted in a section formed by any one of the plurality of spans based on the estimation result. Performance estimation device. The optical transmission performance estimation device according to claim 3, further comprising a determination unit for determining whether or not the signal light can be transmitted in the section based on the calculation result. The estimation unit makes the estimation for the plurality of indexes related to the transmission performance according to the value of n in each of the plurality of spans.
The calculation unit performs the calculation for each of the plurality of spans using any one of the plurality of indicators relating to the transmission performance.
The optical transmission performance estimation device according to claim 3 or 4. The calculation unit performs the calculation using the deterioration amount of the signal light at each of the start point node and the end point node in the section.
The optical transmission performance estimation device according to any one of claims 3 to 5. The calculation unit performs the calculation using the amount of noise generated in the signal light at each of the start point node and the end point node in the section.
The optical transmission performance estimation device according to any one of claims 3 to 6 . The acquisition unit further acquires an index relating to a fourth transmission performance of the signal light transmitted in the span group between the first node and the n + 1 node.
The estimation unit makes the estimation when the index related to the fourth transmission performance is larger than a predetermined threshold value.
The optical transmission performance estimation device according to any one of claims 1 to 7. The estimation unit performs the estimation when the index related to the first transmission performance is less than a predetermined first threshold value and the index related to the second transmission performance is larger than a predetermined second threshold value. ,
The optical transmission performance estimation device according to any one of claims 1 to 7. The acquisition unit acquires the index related to the first transmission performance and the index related to the second transmission performance of the signal light transmission path passing through all the spans in the network formed by the plurality of nodes. Determining part that determines the transmission path,
The optical transmission performance estimation device according to any one of claims 1 to 9 , further comprising the above. In the signal light transmission path connected via a plurality of nodes, the first transmission of the signal light transmitted through the span group between the first node and the nth (n is an integer of 3 or more) nodes. Obtain an index related to performance and an index related to the second transmission performance of the signal light transmitted in a span or a group of spans between the first node and a node of the m (natural number satisfying m <n). death,
Based on the first and second transmission performance indexes, the index regarding the transmission performance of the signal light transmitted in the span between the mth node and the nth node is estimated .
The acquired index related to the first transmission performance is stored, and the index is stored.
An index relating to the third transmission performance of the signal light transmitted in the span between the estimated mth node and the nth node is stored.
An actually measured value of an index relating to the transmission performance of the signal light transmitted through the span group between the first node and the nth node, a stored index relating to the first transmission performance, and the stored index relating to the first transmission performance. The stored index related to the third transmission performance is updated based on the index related to the third transmission performance .
An optical transmission performance estimation method in which a computer executes processing.

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