WO2019078122A1

WO2019078122A1 - Network management device, optical network system, and wavelength usage monitoring method

Info

Publication number: WO2019078122A1
Application number: PCT/JP2018/038147
Authority: WO
Inventors: 竹下　仁士; 慎介藤澤; タヤンディエドゥガボリエマニュエルル
Original assignee: 日本電気株式会社
Priority date: 2017-10-16
Filing date: 2018-10-12
Publication date: 2019-04-25

Abstract

Since it is difficult to easily grasp a wavelength fragmentation state in a wavelength division multiplexing optical communication network, this network management device comprises: a used wavelength information acceptance means that accepts, from a plurality of optical node devices constituting a network, used wavelength information including information relating to the central wavelength of a used frequency slot regarding each of optical fibers to which the plurality of optical node devices are connected; and a wavelength usage monitoring means that, on the basis of the used wavelength information, calculates a frequency usage index that is the number of frequency slots having different central wavelengths from each other, among frequency slots used in the plurality of optical fibers, and monitors wavelength usage in the network using the wavelength usage index.

Description

Network management apparatus, optical network system, and wavelength usage monitoring method

The present invention relates to a network management apparatus, an optical network system, and a wavelength usage monitoring method, and more particularly, to a network management apparatus, an optical network system, and a wavelength usage monitoring method used for an optical communication network based on wavelength division multiplexing.

With the rapid expansion of mobile traffic and video services, the expansion of communication capacity in the core network is required. This demand for capacity expansion tends to continue in the future. In order to continuously expand the communication capacity at a limited cost, it is effective to increase network utilization efficiency by efficiently operating network resources. In particular, in an optical communication network in which the information capacity to be handled is very large, it is important to efficiently use a wavelength band which is a communication resource.

In an optical communication network (wavelength division multiplexing optical communication network) using wavelength division multiplexing (WDM) technology, communication capacity can be expanded by multiplexing optical paths of different wavelengths.

On the other hand, in a WDM optical network, there is a limitation due to the Routing and Spectrum Assignment (RSA) problem that it is necessary to assign the same spectral region in all optical fibers passing through for each path. That is, even if a route for forming an optical path by cascading optical fibers from a transmission point to a reception point is found, if there is no vacancy in a desired wavelength band in all the optical fibers on the route, I can not open the path. In this case, it is necessary to use a wavelength band different from the originally desired wavelength band. This causes fragmentation of the wavelength band, which reduces the utilization efficiency of the optical network. Therefore, in order to increase network utilization efficiency, it is better for the wavelength band fragmentation to be smaller. That is, if wavelength band fragmentation can be suppressed, the utilization efficiency of the optical network can be improved. Therefore, various techniques for reducing wavelength fragmentation have been proposed (see, for example, Patent Document 1).

As described above, in order to use the optical communication network efficiently, it is necessary to maintain a state in which the wavelength fragmentation is small. On the other hand, in general, the state of wavelength fragmentation tends to deteriorate as the generation and extinction of communication traffic, that is, the generation and deletion of optical paths are repeated. Therefore, an operation to reduce wavelength fragmentation, that is, timing to perform wavelength defragmentation is important, and for that purpose, it is necessary to monitor the state of wavelength fragmentation of the optical network.

Patent Document 2 describes an example of a technique for monitoring such a wavelength fragmentation state. The related frequency allocation apparatus described in Patent Document 2 is an apparatus for selecting a path and a frequency connecting the start point and the end point of the optical signal, and includes path / frequency calculation result storage means, common free frequency information generation means, free frequency It comprises state evaluation means and frequency / route determination means.

The path / frequency calculation result storage means stores path / frequency results. The common free frequency information generation means extracts the fiber groups connected to each other, and performs logic operation on the logical information representing the free frequency states of the extracted fiber groups to obtain logical information on free frequency states common to the fibers. Generate The vacant frequency condition evaluation means gives an evaluation value to the vacant frequency condition taking into consideration the continuity of the vacant frequency to the vacant frequency condition common to the fibers based on the vacant frequency information common to the generated fibers. Then, the frequency / path determination means determines the frequency to be set as the communication path and the passing fiber based on the evaluation value calculated by the free frequency state evaluation means, and stores the frequency and the transmission fiber in the path / frequency calculation result storage means.

As described above, in the related frequency assignment device, when the route and the wavelength (frequency) are assigned in order to meet the optical path demand, the utilization status of the wavelength (frequency) in each link is considered. With such a configuration, according to the related frequency assignment device, the occurrence of fragmentation in the optical path network can be effectively suppressed and the utilization efficiency of wavelength (frequency) resources can be optimized. .

Further, as related art, there are technologies described in Patent Documents 3 and 4.

JP, 2015-037247, A International Publication No. 2012/057095 JP, 2014-150440, A International Publication No. 2015/129194

As described above, in the related frequency assignment apparatus, calculation is performed on a plurality of path / frequency candidates (optical path candidates) from the start point node to the end point node. Then, in the case where a plurality of obtained candidates are adopted, an evaluation value is given to the frequency state of the fiber, that is, the wavelength fragmentation state, and an optimum path / frequency is selected based on this evaluation value. Thus, in the related frequency assignment apparatus, in order to obtain the wavelength fragmentation state, it is necessary to obtain the result of light path calculation.

However, optical path calculation requires a great deal of information, such as network topology information, communication traffic information, and optical node device information. In other words, it is necessary to obtain a great deal of calculation parameter information and perform complicated light path calculation. Therefore, in order to acquire the wavelength fragmentation state, a large amount of information and calculation amount are required.

As described above, in the wavelength division multiplexing optical communication network, there is a problem that it is difficult to easily grasp the state of wavelength fragmentation.

An object of the present invention is a network management device, an optical network system, and a network management device that solve the problem that it is difficult to easily grasp the state of wavelength fragmentation in the wavelength division multiplexing optical communication network, which is the above-mentioned problem. It is providing a wavelength usage monitoring method.

The network management apparatus according to the present invention includes information on the center wavelength of the frequency slot being used for each of the optical fibers to which the plurality of optical node devices are connected from the plurality of optical node devices constituting the network. Calculate the wavelength usage status index, which is the number of frequency slots with different center wavelengths among the frequency slots used in a plurality of optical fibers, based on the usage wavelength information reception means for receiving usage wavelength information and the usage wavelength information And wavelength usage monitoring means for monitoring the wavelength usage in the network using the wavelength usage indicator.

The optical network system according to the present invention includes an optical node device provided with used wavelength information acquisition means, and a network management device provided with wavelength use status monitoring means, and the used wavelength information acquisition means constitutes a network. The use wavelength information including information on the center wavelength of the frequency slot being used is obtained for each of the plurality of optical fibers, and the wavelength usage monitoring means is used in the plurality of optical fibers based on the use wavelength information Among the frequency slots, the wavelength usage index indicating the number of frequency slots having different center wavelengths is calculated, and the wavelength usage status in the network is monitored using the wavelength usage index.

The wavelength usage monitoring method of the present invention acquires usage wavelength information including information on the center wavelength of the frequency slot being used for each of the plurality of optical fibers constituting the network, and based on the usage wavelength information Calculate a wavelength usage indicator, which is the number of frequency slots having different center wavelengths among frequency slots used in a plurality of optical fibers, and monitor the wavelength usage in the network using the wavelength usage indicator .

According to the network management device, the optical network system, and the wavelength usage monitoring method of the present invention, it is possible to easily grasp the state of wavelength fragmentation in a wavelength division multiplexing optical communication network.

FIG. 1 is a block diagram showing the configuration of an optical network system according to a first embodiment of the present invention. FIG. 1 is a block diagram showing a configuration of a network management device according to a first embodiment of the present invention. It is a block diagram showing composition of an optical node device concerning a 1st embodiment of the present invention. It is a block diagram which shows another structure of the network management apparatus which concerns on the 1st Embodiment of this invention. It is a block diagram which shows another structure of the optical node apparatus which concerns on the 1st Embodiment of this invention. It is a figure which shows the use condition of a frequency slot for demonstrating operation | movement of the network management apparatus which concerns on the 1st Embodiment of this invention. FIG. 6 is a diagram in which the use situation of frequency slots is mapped for explaining the operation of the network management device according to the first embodiment of the present invention. It is a figure which shows another use condition of a frequency slot for demonstrating the operation | movement of the network management apparatus based on the 1st Embodiment of this invention. FIG. 7 is a diagram in which another use situation of frequency slots is mapped to explain the operation of the network management device according to the first embodiment of the present invention. It is a figure which shows the result of having calculated | required the relationship between the number of wavelengths of the optical path calculated | required using the wavelength usage condition monitoring method which concerns on the 1st Embodiment of this invention, and the number of demands by simulation. It is a figure which shows the network model used in the simulation which showed the result in FIG. 8A.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
FIG. 1 is a block diagram showing the configuration of an optical network system 1000 according to the first embodiment of the present invention.

The optical network system 1000 includes a network management device 1100 and an optical node device 1200. FIG. 1 illustrates the case where the optical network system 1000 includes four optical node devices 1200. The optical node devices 1200 are connected to one another by an optical fiber 1300, respectively. Further, the network management device 1100 and each optical node device 1200 are connected by a control line 1400.

FIG. 2 shows the configuration of the network management device 1100, and FIG. 3 shows the configuration of the optical node device 1200. The network management device 1100 includes a wavelength usage monitoring unit (wavelength usage monitoring means) 1110. The optical node device 1200 further includes a use wavelength information acquisition unit (use wavelength information acquisition unit) 1210.

The used wavelength information acquisition unit 1210 included in the optical node device 1200 acquires, for each of the plurality of optical fibers 1300 forming the network, used wavelength information including information related to the center wavelength of the frequency slot being used. Here, the frequency slot is the frequency defined by the Recommendation of the International Telecommunication Union (ITU) Telecommunication Standardization Sector (ITU-T) (ITU-T Recommendation G.694.1). I say the range.

The wavelength usage monitoring unit 1110 included in the network management apparatus 1100 is the number of frequency slots having different center wavelengths among frequency slots used in the plurality of optical fibers 1300 based on the used wavelength information. Calculate wavelength usage indicator.
Then, the wavelength usage status in the network is monitored using this wavelength usage status index.

As described above, in the optical network system 1000 according to the present embodiment, the wavelength usage monitoring unit 1110 included in the network management apparatus 1100 monitors the wavelength usage in the network using the wavelength usage index. Therefore, it is possible to monitor the wavelength usage in the network, that is, the wavelength fragmentation state, without performing complicated light path calculation. That is, the wavelength usage monitoring unit 1110 functions as a fragmentation monitor.

As described above, according to the optical network system 1000 according to the present embodiment, the state of wavelength fragmentation can be easily grasped in the wavelength division multiplexing optical communication network.

Like the network management apparatus 1101 shown in FIG. 4, the network management apparatus can be configured to further include a use wavelength information reception unit (use wavelength information reception means) 1120 in addition to the wavelength use status monitoring unit 1110. The use wavelength information reception unit 1120 receives use wavelength information for each of the optical fibers 1300 to which the plurality of optical node devices 1200 are connected, from the plurality of optical node devices 1200 configuring the network. Here, the used wavelength information includes information on the center wavelength of the frequency slot being used. The wavelength usage monitoring unit 1110 can be configured to calculate the wavelength usage indicator based on the used wavelength information received by the used wavelength information receiving unit 1120.

Further, as the optical node device 1201 shown in FIG. 5, the optical node device includes a plurality of optical transceivers (transponders) 1220, a multiplexer / demultiplexer 1230, and an optical switch 1240 in addition to the used wavelength information acquisition unit 1210. It can be set as equipped.

Here, the multiplexer / demultiplexer 1230 wavelength division multiplexes the optical signal input / output to / from the plurality of optical transceivers 1220. The optical switch 1240 connects the multiplexer / demultiplexer 1230 and one of the plurality of optical fibers 1300. That is, the optical signals output from the plurality of optical transmitters / receivers 1220 are wavelength-multiplexed in the multiplexer / demultiplexer 1230 to become wavelength-multiplexed optical signals. The optical switch 1240 selects one of the plurality of optical fibers 1300 and outputs a wavelength multiplexing optical signal to the selected optical fiber 1300.

In the optical node device 1201, the use wavelength information acquisition unit 1210, the optical transceiver 1220, and the optical switch 1240 are provided in the same device. Therefore, the use wavelength information acquisition unit 1210 determines whether or not an optical signal is input / output to / from the optical transmitter / receiver 1220, and if it is input / output, the wavelength of the input / output optical signal and the input / output It is possible to easily grasp the above optical fiber. That is, the used wavelength information acquisition unit 1210 acquires the used wavelength information for each of the plurality of optical fibers by monitoring the operating state of the plurality of optical transceivers 1220 and the connection state of the optical switch 1240. it can. In this case, the used wavelength information includes the wavelength of each optical signal included in the wavelength multiplexed optical signal, the identification number of the optical fiber to which the wavelength multiplexed optical signal is to be sent, and the like.

Specifically, the used wavelength information acquisition unit 1210 monitors which one of the optical transceivers (transponders) among the plurality of optical transceivers 1220 is in the ON state. In addition, the used wavelength information acquisition unit 1210 monitors which one of the plurality of optical fibers 1300 the optical switch 1240 is connected to.

The use wavelength information acquisition unit 1210 acquires the use wavelength information by measuring the light intensity (light spectrum) of each wavelength component of the signal light propagating through the optical fiber connected to the optical node device without being limited thereto. It may be configured to

Next, the operation of the network management device 1100 will be described.

The used wavelength information acquired by each optical node device 1200 (1201) is aggregated in the network management device 1100 through the control line 1400 and the like. The wavelength usage monitoring unit 1110 included in the network management apparatus 1100 calculates a wavelength usage indicator based on the used wavelength information, and monitors the wavelength usage in the network using the wavelength usage indicator. Here, as described above, the wavelength usage index is the number of frequency slots having different center wavelengths among the frequency slots used in the plurality of optical fibers 1300.

Next, the operation of the wavelength usage monitoring unit 1110 will be described in detail.

The wavelength usage monitoring unit 1110 classifies the frequency slots used in the entire plurality of optical fibers 1300 according to the central wavelength into one type of frequency slot for each central wavelength. The wavelength usage indicator can be calculated by using the number of frequency slot types as the wavelength usage indicator.

Hereinafter, the operation of calculating the wavelength use status indicator will be described using a specific example.

FIGS. 6A and 7A show the use of frequency slots in each of the plurality of optical fibers 1301-1304 constituting the network. The vertical axis of each figure is the identification number of the optical fiber, and the horizontal axis is the center wavelengths λ1 to λ6 of the frequency slot. The hatching in each figure shows the frequency slot being used.

Here, the vertical row for each center wavelength in FIGS. 6A and 7A corresponds to the frequency slot type. Thus, in the case of the frequency slot usage shown in FIG. 6A, the number of frequency slot types is six, and the total number of frequency slots used is eight. On the other hand, in the case of the use situation of the frequency slot shown in FIG. 7A, the number of frequency slot types is three and the total number of frequency slots used is eight.

The wavelength usage monitoring unit 1110 maps the usage status of the frequency slot using the usage wavelength information sent from each optical node device 1200, and creates the wavelength usage table shown in FIGS. 6B and 7B. Here, as shown in the figures, the wavelength use status table is created with “1” as the frequency slot in use and “0” as the frequency slot not in use.

For example, in the case of the use status shown in FIG. 6A, in the optical fiber 1301, the frequency slots of the center wavelengths λ1 and λ5 are in use, so the row of the optical fibers 1301 in the wavelength use status table is “100010”. . Further, in the optical fiber 1302, since the frequency slots of which the central wavelength is λ2 and λ3 are in use, the row of the optical fiber 1302 in the wavelength usage status table is “011000”.

The wavelength usage monitoring unit 1110 obtains a logical sum (OR) for each central wavelength in the wavelength usage tables shown in FIGS. 6B and 7B. For example, in the case shown in FIG. 6B, the logical sum (OR) is “1” for all of the central wavelengths λ1 to λ6. On the other hand, in the case shown in FIG. 7B, the logical sum (OR) is “1” for the central wavelengths λ1 to λ3, and the logical sum (OR) is “0” for the central wavelengths λ4 to λ6.

The wavelength usage monitoring unit 1110 obtains the number of frequency slot types from the result of calculating the logical sum (OR), and uses this number as a wavelength usage indicator. Specifically, in the example of the usage state of the frequency slot shown in FIG. 6A, the logical sum (OR) is “1” for all the central wavelengths λ1 to λ6, so the wavelength usage indicator, ie, the central wavelengths The number of different frequency slots is "6". On the other hand, in the example of the use status of the frequency slot shown in FIG. 7A, the logical use (OR) becomes “1” only for the central wavelengths λ1 to λ3, and the wavelength use index is “3”.

Here, in the example of the usage condition of the frequency slot shown in FIGS. 6A and 7A, the total number of frequency slots determined regardless of whether the center wavelength of the frequency slot is the same is eight in any case. However, in the use situation shown in FIG. 6A, multiple frequency slots having different central wavelengths are used, and there are no unused frequency slots having central wavelengths different from the frequency slots in use. On the other hand, in the use situation shown in FIG. 7A, the central wavelengths of the frequency slots in use are limited to λ1, λ2 and λ3, and the frequency slots with central wavelengths λ4, λ5 and λ6 are either It is also unused in the optical fiber.

Thus, although the total number of frequency slots in use is the same, there are few frequency slot types in the use situation shown in FIG. 7A. Therefore, as wavelength bands occupied by the frequency slots, three wavelength bands having center wavelengths λ4, λ5, and λ6 are unused and idle. On the other hand, in the use situation shown in FIG. 6A, there are many types of frequency slots, and there is no space in the wavelength band occupied by the frequency slots. That is, it can be seen that the wavelength fragmentation increases as the number of frequency slot types (wavelength usage indicator) increases. Thus, the wavelength usage indicator is an indicator of wavelength fragmentation.

Further, in the use situation shown in FIG. 6A, since the frequency slot in use exists in any of the optical fibers, it is not always possible to open a new optical path between any points. On the other hand, in the use situation shown in FIG. 7A, since it is possible to use frequency slots whose center wavelength is λ4, λ5, or λ6 in all the optical fibers, it is possible to use new optical paths between any points. It can be opened to accommodate additional information traffic.

That is, the use state shown in FIG. 6A is a state in which the utilization efficiency of the optical network is deteriorated because the wavelength fragmentation is large. On the other hand, the use state shown in FIG. 7A is a state in which the utilization efficiency of the optical network is not deteriorated because the wavelength fragmentation is small.

As described above, by using the wavelength use condition indicator calculated by the wavelength use condition monitoring unit 1110, it is possible to easily grasp the deterioration condition of the use efficiency of the optical network caused by the wavelength fragmentation.

Next, the wavelength usage monitoring method according to the present embodiment will be described.

In the wavelength usage monitoring method according to the present embodiment, first, used wavelength information including information on the central wavelength of the frequency slot being used is acquired for each of the plurality of optical fibers constituting the network. Next, based on the use wavelength information, a wavelength use condition index, which is the number of frequency slots having different center wavelengths among the frequency slots used in the plurality of optical fibers, is calculated. Then, the wavelength usage status in the network is monitored using this wavelength usage status index.

Such a configuration makes it possible to monitor the wavelength usage condition in the network, that is, the wavelength fragmentation condition, without performing complicated optical path calculation.

When calculating the wavelength usage index described above, the frequency slots used throughout the plurality of optical fibers are classified according to the center wavelength and aggregated into frequency slot types for each center wavelength, and the number of frequency slot types is calculated. A wavelength usage status indicator may be used.

As described above, according to the network management device, the optical network system, and the wavelength usage monitoring method of the present embodiment, it is possible to easily grasp the state of wavelength fragmentation in a wavelength division multiplexing optical communication network.

Second Embodiment
Next, a second embodiment of the present invention will be described. The configurations of the network management device and the optical node device according to the present embodiment are the same as those according to the first embodiment (see FIGS. 2 to 5). Hereinafter, operations of the network management device and the optical node device according to the present embodiment will be described.

When the used wavelength information changes, the used wavelength information acquisition unit 1210 included in the optical node device 1200 (1201) according to the present embodiment acquires updated used wavelength information that is used wavelength information after the change. Then, the wavelength usage monitoring unit 1110 included in the network management apparatus 1100 (1101) according to the present embodiment calculates a wavelength usage indicator based on the updated wavelength information. In this case, when the used wavelength information changes, the used wavelength information reception unit included in the network management apparatus 1101 receives the updated used wavelength information, which is used wavelength information after the change.

When the communication traffic in the optical network increases or decreases and the number of demands changes with time, the optical path is newly opened, or the opened optical path is repeatedly disconnected and deleted. Therefore, the wavelength use status table (FIGS. 6B and 7B) in which the use status of the frequency slot is mapped using the use wavelength information changes with time. That is, the position where “1” appears, which indicates that the frequency slot is in use in the wavelength use status table, changes with time. Therefore, the number of frequency slot types (wavelength usage condition index) obtained from the result of calculating the logical sum (OR) of each central wavelength also changes with time.

Even in such a case, according to the optical network system of the present embodiment, with the above-described configuration, it is possible to follow the time change of the wavelength use condition index.

Here, when the operating state (on or off) of any of the plurality of optical transceivers 1220 changes, the operating wavelength information acquiring unit 1210 included in the optical node device 1201 acquires operating wavelength information at this timing. can do. Also, as described in the first embodiment, used wavelength information is obtained by measuring the light intensity of each wavelength component of signal light propagating in the optical fiber connected to the optical node device 1200 (1201). It may be configured to
In this case, the used wavelength information acquisition unit 1210 can be configured to acquire used wavelength information when the number of wavelength components whose light intensity is equal to or greater than a predetermined intensity changes.

Also, the network management apparatus can use such time-varying wavelength usage indicator as a trigger for starting wavelength defragmentation. This makes it possible to suppress wavelength fragmentation in the optical network below a certain level. Here, as described in the first embodiment, the wavelength usage index is the number of frequency slots having different center wavelengths among frequency slots used in a plurality of optical fibers, It can be a number.

The above-described wavelength defragmentation refers to rearrangement of fragmented unused frequency slots. Wavelength defragmentation involves temporarily cutting and reconnecting the optical path. Therefore, in order to keep the reliability of the optical path high, it is essential to reduce the number of times of wavelength defragmentation as much as possible. If the number of times of wavelength defragmentation is frequently performed, there is an increased risk that the optical path in use may be erroneously disconnected or the optical path may not be reconnected normally after the disconnection.

As described above, according to the network management apparatus of the present embodiment, since the wavelength use status indicator serving as the index of wavelength fragmentation can be easily obtained, the status of wavelength fragmentation can be grasped. As a result, appropriate timing to start wavelength defragmentation can be obtained. Therefore, according to the network management apparatus of the present embodiment, by using the wavelength usage index as a trigger for starting wavelength defragmentation, the number of times of wavelength defragmentation can be minimized.

For example, if wavelength defragmentation is periodically performed, the possibility of performing wavelength defragmentation more than necessary increases. As a result, the risk associated with the reconnection of the optical path is increased, and the reliability of the optical network is reduced. According to the network management apparatus of the present embodiment, such a problem can be avoided.

FIG. 8A shows the result of simulation for determining the relationship between the amount of generated information traffic (the number of demands) in the optical network and the number of wavelengths of the optical path required to accommodate each information traffic.

In the above simulation, optical path design was performed by performing path calculation using the Dijkstra method. Here, the number of wavelengths of the optical path is the number of frequency slot types (wavelength usage index) obtained using the wavelength usage monitoring method according to the first embodiment, that is, the number of frequency slots having different central wavelengths. . In addition, as a network model, a Japanese version photonic network model JPN48 (Japan Photonic Network 48 model) in which one information communication node is arranged in each prefecture (two locations only in Tokyo) is used (see FIG. 8B).

From FIG. 8A, when the number of required wavelengths increases in proportion to the number of demands and the number of demands reaches about 1000, the network model used (FIG. 8B) runs short of the number of wavelengths that can be provided, and the more demand It turns out that it can not be accommodated. The relationship between the number of demands and the number of wavelengths illustrated in FIG. 8A can be obtained in advance by calculation, and can be stored in the wavelength usage monitoring unit 1110 included in the network management apparatus 1100.

In the simulation result shown in FIG. 8A, for example, when the number of demands is 200, the minimum number of wavelengths required to accommodate the information traffic is 60. As described above, when the number of wavelengths is the minimum necessary number, the usage status of the frequency slot is as shown in FIG. 7A, and the wavelength fragmentation is small. On the other hand, when the wavelength fragmentation is large, the usage of frequency slots, that is, the allocation of wavelengths in the optical network is in an inefficient state as shown in FIG. 6A. Therefore, the number of wavelengths greater than the minimum number of wavelengths required to accommodate information traffic is required.

That is, it is understood from FIG. 8A that, for example, when the number of demands is 200, the number of wavelengths required for achieving a state in which wavelength fragmentation is sufficiently suppressed is 60.
And, it is shown that the number of wavelengths is greater than 60 if suppression of wavelength fragmentation is not sufficient.

According to the network management apparatus according to the present embodiment, as described above, the number of wavelengths currently in use can be easily monitored. Therefore, for example, when the current demand number is 200, if the number of wavelengths currently in use is 60, it can be easily understood that wavelength fragmentation is hardly generated. Then, it can be easily known that the wavelength fragmentation increases as the number of wavelengths increases from 60.

In addition, the wavelength use condition monitoring unit provided in the network management apparatus according to the present embodiment can be configured to generate warning information (alarm) when the number of wavelengths (wavelength use condition indicators) exceeds a predetermined threshold. At this time, the wavelength usage monitoring unit can determine the predetermined threshold based on the number of wavelengths in the optical path (wavelength usage indicator) required to accommodate the traffic request to the network.

Specifically, for example, in the simulation result shown in FIG. 8A, when the number of demands increases or decreases, but the maximum number is limited to 200, the wavelength usage monitoring unit sets the threshold to 60 in advance, and exceeds this threshold Issue an alarm if The network management device can then use this alarm as a trigger to initiate wavelength defragmentation.

As described above, according to the network management device, the optical network system, and the wavelength usage monitoring method of the present embodiment, it is possible to easily grasp the state of wavelength fragmentation in a wavelength division multiplexing optical communication network. As a result, since the appropriate timing for starting wavelength defragmentation can be obtained, the number of times of wavelength defragmentation can be minimized.

Third Embodiment
Next, a third embodiment of the present invention will be described. The configurations of the network management device and the optical node device according to the present embodiment are the same as those according to the first embodiment (see FIGS. 2 to 5). Hereinafter, the operation of the network management apparatus according to the present embodiment will be described.

The operation until the wavelength usage monitoring unit of the network management apparatus according to this embodiment issues a trigger for starting wavelength defragmentation is the same as that of the second embodiment.

When the wavelength usage monitoring unit issues a trigger, the network management apparatus instructs each of the optical node devices 1200 configuring the optical network system 1000 to start the wavelength defragmentation operation.

The wavelength usage monitoring unit recalculates the wavelength usage index that is an index of wavelength fragmentation when the wavelength defragmentation operation is completed. The network management apparatus determines that wavelength defragmentation has succeeded if the recalculated result is less than or equal to a predetermined threshold. If it does not fall below the threshold, wavelength defragmentation is judged as failure or insufficient. In this case, the network management device instructs again to perform the wavelength defragmentation operation. If this re-instruction has reached a predetermined number of times or more, the network management apparatus determines that the communication capacity of the optical network is insufficient, and issues an alarm to the user prompting installation of equipment.

Hereinafter, the simulation result shown in FIG. 8A will be specifically described as an example. If the number of demands to be accommodated by the network is 1000 or more, the number of wavelengths required to accommodate the demand can not be smaller than 160 no matter how many times wavelength defragmentation is performed.

In this case, the network management apparatus presets the threshold of the number of wavelengths in the wavelength usage monitoring unit to 160, and issues an alarm when the current monitor value of the number of wavelengths (wavelength usage indicator) exceeds 50% of the threshold. Do. The alarm allows the user to add an optical fiber and increase the number of usable wavelengths. This makes it possible to know the appropriate timing for adding an optical fiber, even when the number of demands to be accommodated is increasing. As a result, since it is possible to prevent the optical fiber from being unnecessarily installed, the cost for installing the optical network can be reduced.

As described above, according to the network management apparatus of the present embodiment, it is possible to easily grasp the state of wavelength fragmentation in a wavelength division multiplexing optical communication network. As a result, since it is possible to know the appropriate timing to add an optical fiber, the cost of adding an optical network can be reduced.
Some or all of the above embodiments may be described as in the following appendices, but is not limited to the following.
(Supplementary Note 1) Use wavelength information including information on the center wavelength of the frequency slot being used for each of the optical fibers connected to the plurality of optical node devices from the plurality of optical node devices constituting the network Wavelength usage status indicator, which is the number of frequency slots having different center wavelengths among the frequency slots used in the plurality of optical fibers, based on the usage wavelength information receiving means for receiving And a wavelength usage monitoring means for monitoring the wavelength usage in the network using the wavelength usage indicator.
(Supplementary Note 2) The wavelength usage monitoring means classifies, according to the central wavelength, the frequency slots used in all of the plurality of optical fibers into a frequency slot type for each central wavelength, and the frequency The network management device according to claim 1, wherein the wavelength usage indicator is calculated by setting the number of slot types as the wavelength usage indicator.
(Supplementary Note 3) When the used wavelength information changes, the used wavelength information receiving unit receives updated used wavelength information that is the used wavelength information after the change, and the wavelength used status monitoring means includes the updated used wavelength. The network management device described in

appendix

1 or 2, wherein the wavelength use status indicator is calculated based on information.
(Supplementary note 4) The network management device according to any one of supplementary notes 1 to 3, wherein the wavelength usage monitoring means generates warning information when the wavelength usage indicator exceeds a predetermined threshold.
(Supplementary Note 5) The network management described in Supplementary Note 4, wherein the wavelength usage monitoring means determines the predetermined threshold based on the wavelength usage indicator in the optical path required to accommodate the traffic request for the network. apparatus.
(Supplementary Note 6) A plurality of optical node devices provided with used wavelength information acquisition means, and a network management device provided with wavelength use status monitoring means, wherein the used wavelength information acquisition means comprises a plurality of networks. The use wavelength information including information on the center wavelength of the frequency slot being used is obtained for each of the optical fibers, and the wavelength use condition monitoring means is used in the plurality of optical fibers based on the use wavelength information An optical network system that calculates a wavelength use status indicator that is the number of the frequency slots having different central wavelengths among the frequency slots that are running, and that uses the wavelength use status indicator to monitor the wavelength use status in the network .
(Supplementary Note 7) The wavelength usage monitoring means classifies, according to the central wavelength, the frequency slots used in all of the plurality of optical fibers into one frequency slot type for each central wavelength, and the frequency The optical network system described in appendix 6, wherein the wavelength usage indicator is calculated by using the number of slot types as the wavelength usage indicator.
(Supplementary Note 8) When the used wavelength information changes, the used wavelength information acquisition means acquires updated used wavelength information that is the used wavelength information after the change, and the wavelength use status monitoring means includes the updated use information. The optical network system described in appendix 6 or 7, wherein the wavelength use status indicator is calculated based on wavelength information.
(Supplementary note 9) The optical network system according to any one of supplementary notes 6 to 8, wherein the wavelength usage monitoring means generates warning information when the wavelength usage indicator exceeds a predetermined threshold.
(Supplementary note 10) The optical network according to supplementary note 9, wherein the wavelength usage monitoring means determines the predetermined threshold based on the wavelength usage indicator in the optical path required to accommodate the traffic request to the network. system.
(Supplementary note 11) The optical node device includes a plurality of optical transceivers, a multiplexer / demultiplexer that wavelength division multiplexes optical signals input to and output from the plurality of optical transceivers, the multiplexer / demultiplexer, and the plurality of light The optical network system according to any one of appendices 6 to 10, further comprising: an optical switch connecting one of the fibers.
(Supplementary Note 12) The optical network system according to Supplementary Note 11, wherein the use wavelength information acquisition unit acquires the use wavelength information by monitoring the operating states of the plurality of optical transceivers and the connection state of the optical switch.
(Supplementary note 13) The optical network system according to supplementary note 12, wherein the use wavelength information acquisition unit acquires the use wavelength information when an operation state of any of the plurality of optical transceivers changes.
(Supplementary Note 14) The use wavelength information acquisition unit acquires the use wavelength information by measuring the light intensity of each wavelength component of the signal light propagating through the optical fiber connected to the optical node device. The optical network system described in 11.
(Supplementary note 15) The optical network system according to supplementary note 14, wherein the operating wavelength information acquisition unit acquires the operating wavelength information when the number of wavelength components whose light intensity is equal to or higher than a predetermined intensity changes.
(Supplementary Note 16) Use wavelength information including information on the center wavelength of the frequency slot being used is acquired for each of the plurality of optical fibers constituting the network, and the plurality of lights are obtained based on the use wavelength information. Among the frequency slots used in the fiber, a wavelength usage indicator, which is the number of the frequency slots having different central wavelengths, is calculated, and the wavelength usage in the network is monitored using the wavelength usage indicator. Wavelength usage monitoring method.
(Supplementary Note 17) The calculation of the wavelength usage status index may be performed by classifying the frequency slots used in the entire plurality of optical fibers according to the center wavelength and aggregating them into frequency slot types for each center wavelength. The wavelength usage monitoring method according to claim 16, further comprising using the number of frequency slot types as the wavelength usage indicator.
(Supplementary note 18) When the use wavelength information changes, the update use wavelength information that is the use wavelength information after change is acquired, and the wavelength use condition index is calculated based on the update use wavelength information. Or the wavelength usage monitoring method described in 17.
(Supplementary note 19) The wavelength use condition monitoring method according to any one of supplementary notes 16 to 18, which generates warning information when the wavelength use condition index exceeds a predetermined threshold.
(Supplementary note 20) The wavelength usage monitoring method according to Supplementary note 19, wherein the predetermined threshold is determined based on the wavelength usage indicator in an optical path required to accommodate a traffic request to the network.
(Supplementary note 21) Among the frequency slots used in the plurality of optical fibers based on used wavelength information including information on the center wavelength of the frequency slot used in the plurality of optical fibers constituting the network A network management apparatus having wavelength use status monitoring means for calculating a wavelength use status indicator which is the number of the frequency slots different from each other in the central wavelength, and monitoring the wavelength use status in the network using the wavelength use status indicator; .
(Supplementary note 22) An optical node device having use wavelength information acquisition means for acquiring use wavelength information including information on the center wavelength of a used frequency slot for each of a plurality of optical fibers constituting a network.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. The configurations and details of the present invention can be modified in various ways that can be understood by those skilled in the art within the scope of the present invention.
This application claims priority based on Japanese Patent Application No. 2017-200509 filed on October 16, 2017, the entire disclosure of which is incorporated herein.

1000

Optical Network System

1100, 1101 Network Management Device 1110 Wavelength Usage Monitoring Unit 1120 Wavelength

Information Reception Unit

1200, 1201 Optical Node Unit 1210 Wavelength Information Acquisition Unit 1220 Optical Transmitter / Receiver 1230 Coupler / Demultiplexer 1240 Optical Switch 1300 Optical Fiber 1400 Control line

Claims

A use wavelength for receiving information on the center wavelength of the frequency slot being used for each of the optical fibers to which the plurality of optical node devices are connected, from the plurality of optical node devices constituting the network Information acceptance means,
Based on the use wavelength information, a wavelength use condition index, which is the number of the frequency slots having different center wavelengths among the frequency slots used in the plurality of optical fibers, is calculated, and the wavelength use condition index And a wavelength usage monitoring means for monitoring the wavelength usage in the network.
The wavelength usage monitoring means classifies, according to the central wavelength, the frequency slots used throughout the plurality of optical fibers into a frequency slot type for each central wavelength, and the number of the frequency slot types The network management device according to claim 1, wherein the wavelength use status indicator is calculated by setting the wavelength use status indicator as the wavelength use status indicator.
When the used wavelength information changes, the used wavelength information receiving unit receives update used wavelength information that is the used wavelength information after the change.
The network management device according to claim 1, wherein the wavelength usage monitoring means calculates the wavelength usage indicator based on the updated usage wavelength information.
The network management device according to any one of claims 1 to 3, wherein the wavelength usage monitoring means generates warning information when the wavelength usage index exceeds a predetermined threshold.
5. The network management device according to claim 4, wherein the wavelength usage monitoring means determines the predetermined threshold based on the wavelength usage indicator in an optical path required to accommodate a traffic request for the network.
An optical node device provided with used wavelength information acquisition means;
A network management device provided with wavelength usage monitoring means;
The use wavelength information acquisition means acquires use wavelength information including information on the center wavelength of the frequency slot being used for each of the plurality of optical fibers constituting the network,
The wavelength usage monitoring means may, based on the used wavelength information, select a wavelength usage indicator, which is the number of the frequency slots having different central wavelengths among the frequency slots used in the plurality of optical fibers. An optical network system that calculates and monitors wavelength usage in the network using the wavelength usage indicator.
The wavelength usage monitoring means classifies, according to the central wavelength, the frequency slots used throughout the plurality of optical fibers into a frequency slot type for each central wavelength, and the number of the frequency slot types The optical network system according to claim 6, wherein the wavelength use condition indicator is calculated by setting the wavelength use condition indicator as the wavelength use condition indicator.
The use wavelength information acquisition means acquires update use wavelength information which is the use wavelength information after the change when the use wavelength information changes,
The optical network system according to claim 6, wherein the wavelength usage monitoring means calculates the wavelength usage indicator based on the updated usage wavelength information.
The optical network system according to any one of claims 6 to 8, wherein the wavelength usage monitoring means generates warning information when the wavelength usage index exceeds a predetermined threshold.
The optical network system according to claim 9, wherein the wavelength usage monitoring means determines the predetermined threshold based on the wavelength usage indicator in an optical path required to accommodate a traffic request for the network.
The optical node device
With multiple optical transceivers,
A multiplexer / demultiplexer that wavelength-division multiplexes an optical signal input / output to / from the plurality of optical transceivers;
The optical network system according to any one of claims 6 to 10, further comprising: the multiplexer / demultiplexer and an optical switch connecting one of the plurality of optical fibers.
The optical network system according to claim 11, wherein the used wavelength information acquisition unit acquires the used wavelength information by monitoring the operating state of the plurality of optical transceivers and the connection state of the optical switch.
The optical network system according to claim 12, wherein the used wavelength information acquisition unit acquires the used wavelength information when an operation state of any of the plurality of optical transceivers changes.
The used wavelength information acquisition means acquires the used wavelength information by measuring the light intensity of each wavelength component of the signal light propagating in the optical fiber connected to the optical node device. Optical network system.
The optical network system according to claim 14, wherein the used wavelength information acquisition unit acquires the used wavelength information when the number of the wavelength components whose light intensity is equal to or more than a predetermined intensity changes.
Acquiring use wavelength information including information on the center wavelength of the frequency slot being used for each of a plurality of optical fibers constituting the network;
Based on the used wavelength information, among the frequency slots used in the plurality of optical fibers, a wavelength use condition index, which is the number of the frequency slots having different central wavelengths, is calculated.
A wavelength usage monitoring method for monitoring a wavelength usage in the network using the wavelength usage indicator.
The calculation of the wavelength use status index may be performed by classifying the frequency slots used in the entire plurality of optical fibers according to the central wavelength into one frequency slot type for each central wavelength, and the frequency slot The wavelength usage monitoring method according to claim 16, comprising setting the number of types as the wavelength usage indicator.
When the used wavelength information changes, the updated used wavelength information which is the used wavelength information after the change is acquired,
The wavelength usage monitoring method according to claim 16, wherein the wavelength usage index is calculated based on the updated usage wavelength information.
The wavelength usage monitoring method according to any one of claims 16 to 18, generating warning information when the wavelength usage index exceeds a predetermined threshold.
20. The wavelength usage monitoring method according to claim 19, wherein the predetermined threshold is determined based on the wavelength usage indicator in an optical path required to accommodate a traffic request for the network.
Among the frequency slots used in the plurality of optical fibers, the central wavelength among the frequency slots used in the plurality of optical fibers based on used wavelength information including information on the center wavelength of the frequency slot used in the plurality of optical fibers configuring the network A network management apparatus comprising: wavelength use status monitoring means for calculating a wavelength use status indicator which is the number of the frequency slots different from one another and using the wavelength use status indicator to monitor the wavelength use status in the network.
An optical node device having use wavelength information acquisition means for acquiring use wavelength information including information on the center wavelength of a frequency slot being used for each of a plurality of optical fibers constituting a network.