Optical Network Management Device, Optical Network System, Optical Network Management Method, and Optical Network Management Program

Abstract

To increase wavelength utilization efficiency in an optical network system including a multi-core optical fiber.SOLUTION: An optical network management device (100) that allocates a path from a transmission node to a reception node in an optical network system including a multi-core optical fiber includes a core extraction unit (11) that extracts cores that form the path, and a path allocation unit (12) that selects a wavelength to which the path is allocated according to the attribute of the path, an optical amplifier is attached to the multi-core optical fiber, and the amplification gain of the optical amplifier is greater in a first wavelength region than in a second wavelength region, and the path allocation unit (12) assigns a path having a specific attribute to the first wavelength region with priority.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a path accommodation technique in an optical network system including a multi-core fiber.

Background Art

[0002] In recent years, due to the rapid spread of mobile terminals typified by smartphones and the communication of large-capacity data such as high-definition images resulting from the sophistication of terminals, the traffic flowing through the network has been continuously growing rapidly. Therefore, various transmission capacity expansion technologies have been developed. For example, for the purpose of expanding the transmission capacity per optical fiber, research and development of a multi-core optical fiber (MCF) in which a plurality of cores are filled in one cladding has been promoted.

[0003] In addition, research and development of a technology for effectively utilizing limited frequency resources has also been promoted. For example, research and development of a network control technology that reduces path blocking and improves frequency utilization efficiency by allocating paths according to the signal quality of the transmission line, the bandwidth of the communication signal, the communication distance, etc. has been promoted.

[0004] In the MCF, since crosstalk from adjacent cores varies depending on the physical position of the cores, there are variations in characteristics for each core. As a network control technology considering this point, Patent Document 1 and Patent Document 2 disclose a method of effectively utilizing cores by arranging a main signal in a peripheral core with good characteristics and arranging a monitor signal slower than the main signal in a central core with inferior characteristics. In addition, Patent Document 3 discloses a method of allocating paths according to the signal quality difference of the cores and the transmission distance of the main signal.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] However, what has been considered in the prior art is only to allocate paths in consideration of the characteristic differences between cores in a transmission line. Therefore, it would be useful if the wavelength utilization efficiency in an optical network system including a multi-core optical fiber could be increased by a novel method.

[0007] One aspect of the present invention has been made in view of the above problems, and an example of its object is to provide a novel technique for increasing the wavelength utilization efficiency in an optical network system including a multi-core optical fiber. [Means for Solving the Problems]

[0008] An optical network management device according to one aspect of the present invention is an optical network management device that allocates a path from a transmission node to a reception node in an optical network system including a multi-core optical fiber, and includes a core extraction unit that extracts cores constituting the path, and a path allocation unit that selects a wavelength to which the path is to be allocated according to an attribute of the path. An optical amplifier is attached to the multi-core optical fiber, and the amplification gain of the optical amplifier increases in a first wavelength region more than in a second wavelength region. The path allocation unit preferentially allocates the path having a specific attribute to the first wavelength region.

[0009] The optical network management method according to one aspect of the present invention is an optical network management method for allocating a path from a transmission node to a reception node in an optical network system including a multi-core optical fiber, the method including extracting cores constituting the path and selecting a wavelength for allocating the path according to the attributes of the path, wherein an optical amplifier is attached to the multi-core optical fiber, and the amplification gain of the optical amplifier increases in a first wavelength region more than in a second wavelength region, and selecting a wavelength for allocating the path includes preferentially allocating the path having specific attributes to the first wavelength region.

[0010] The optical network management program according to one aspect of the present invention is an optical network management program for causing a computer to function as an optical network management device that allocates a path from a transmission node to a reception node in an optical network system including a multi-core optical fiber, the program causing the computer to function as a core extraction unit that extracts cores constituting the path and a path allocation unit that selects a wavelength for allocating the path according to the attributes of the path, wherein an optical amplifier is attached to the multi-core optical fiber, and the amplification gain of the optical amplifier increases in a first wavelength region more than in a second wavelength region, and the path allocation unit preferentially allocates the path having specific attributes to the first wavelength region.

Advantages of the Invention

[0011] According to one aspect of the present invention, it is possible to improve the wavelength utilization efficiency in an optical network system including a multi-core optical fiber.

Brief Description of the Drawings

[0012]

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Mode for Carrying Out the Invention

[0013] 〔Exemplary Embodiment 1〕 The first exemplary embodiment of the present invention will be described in detail with reference to the drawings. This exemplary embodiment is a basic form for the exemplary embodiments described later.

[0014] <Configuration of System and Apparatus> The configurations of the optical network system 1 and the optical network management apparatus 100 according to this exemplary embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram schematically showing an example of the configuration of the optical network system 1. FIG. 2 is a block diagram showing an example of the configuration of the optical network management apparatus 100.

[0015] The optical network system 1 is an optical network system including a multi-core optical fiber. In one aspect, the optical network system 1 may be a heterogeneous optical network system in which a multi-core optical fiber and a single-core optical fiber are mixed.

[0016] As shown in FIG. 1, the optical network system 1 includes an optical network management apparatus 100, a node 101, an optical transmission path 102, and an optical amplifier 105.

[0017] The optical network management apparatus 100, also referred to as an NMS (Network Management System), controls the optical network system 1. In one aspect, the optical network management apparatus 100 controls each node 101 to allocate a path from a transmission node to a reception node.

[0018] The optical transmission path 102 is composed of a ring 103 connecting a plurality of nodes 101 and a connection link 104 connecting a plurality of rings 103. The optical transmission path 102 includes a multi-core optical fiber. The optical transmission path 102 may be partly composed of a multi-core optical fiber and partly composed of a single-core optical fiber, or may be entirely composed of a multi-core optical fiber.

[0019] An optical amplifier 105 for compensating for the transmission loss of light passing through the optical transmission path 102 is attached to the optical transmission path 102. The amplification gain of the optical amplifier 105 is configured to increase in a first wavelength region rather than in a second wavelength region.

[0020] As shown in FIG. 2, the optical network management apparatus 100 includes a control unit 10, a storage unit 20, and a network interface 30.

[0021] The control unit 10 includes a core extraction unit 11, a path assignment unit 12, and a node control unit 13. The core extraction unit 11 extracts a core that constitutes a path connecting a transmission node to a reception node from the cores included in each optical transmission path 102 in the optical network system 1.

[0022] The path assignment unit 12 selects a wavelength for assigning a path according to the attributes of the path. The attributes of the path are not particularly limited, and examples thereof include the bandwidth, distance, importance, type, etc. of the path. The type of the path is not particularly limited, and examples thereof include the type of whether the path is an active system or a standby system (protection path). In one aspect, the path assignment unit 12 preferentially assigns a path having a specific attribute to the first wavelength region.

[0023] The node control unit 13 controls each node 101 so that a path is assigned to the wavelength assigned by the path assignment unit 12 on the core extracted by the core extraction unit 11.

[0024] The storage unit 20 stores program data executed by the control unit 10, data referred to when executing the program data, and the like. The storage unit 20 is configured by a non-volatile storage device such as a hard disk or a flash memory, for example.

[0025] The network interface 30 is an interface used for communicating with any other device (for example, the node controller of the node 101).

[0026] <Flow of the optical network management method> The procedure of the optical network management method according to the present exemplary embodiment will be described with reference to FIG. 3. FIG. 3 is a flowchart showing an example of the procedure of the optical network management method according to the present exemplary embodiment. As shown in FIG. 3, the optical network management method according to the present exemplary embodiment includes at least steps S1 to S2.

[0027] In step S1 (core extraction process), the core extraction unit 11 extracts a core that constitutes a path connecting from the transmission node to the reception node from the cores included in each optical transmission line 102 in the optical network system 1.

[0028] In step S2 (path assignment process), the path assignment unit 12 selects a wavelength for path assignment according to the attributes of the path. In one aspect, the path assignment unit 12 preferentially assigns a path having a specific attribute to the first wavelength region.

[0029] Here, the specific attribute is an attribute for which communication should be preferentially performed. For example, but not limited to these, in terms of the bandwidth of the path, it is an attribute of wide bandwidth, in terms of the distance of the path, it is an attribute of long distance, in terms of the importance of the path, it is an attribute of importance, and in terms of the type of the path, it is an attribute of the active system. By preferentially assigning a path with such an attribute to a wavelength region where the wavelength characteristics of the optical transmission line 102 are good, that is, the first wavelength region where the amplification gain of the optical amplifier 105 is large, the wavelength utilization efficiency can be increased.

[0030] As described above, the optical network management device 100 according to this exemplary embodiment is an optical network management device that assigns a path from a transmission node to a reception node in an optical network system 1 including a multi-core optical fiber. The optical network management device 100 includes a core extraction unit 11 that extracts cores constituting the path, and a path assignment unit 12 that selects a wavelength to which the path is assigned according to the attributes of the path. An optical amplifier 105 is attached to the multi-core optical fiber, and the amplification gain of the optical amplifier 105 increases in a first wavelength region more than in a second wavelength region. The path assignment unit 12 is configured to preferentially assign paths having specific attributes to the first wavelength region.

[0031] Further, the optical network management method according to this exemplary embodiment is an optical network management method that assigns a path from a transmission node to a reception node in an optical network system including a multi-core optical fiber. The method includes extracting cores constituting the path and selecting a wavelength to which the path is assigned according to the attributes of the path. An optical amplifier is attached to the multi-core optical fiber, and the amplification gain of the optical amplifier increases in a first wavelength region more than in a second wavelength region. Selecting the wavelength to which the path is assigned includes preferentially assigning the path having specific attributes to the first wavelength region.

[0032] Therefore, according to the optical network management device and the optical network management method according to this exemplary embodiment, it is possible to perform path assignment according to the attributes of the path in consideration of the wavelength characteristics of the optical transmission path. As a result, the wavelength utilization efficiency in the optical network system including the multi-core optical fiber can be increased. And since the wavelength utilization efficiency of the entire optical network system can be increased, it is possible to reduce the cost of the entire optical network system.

[0033] As described above, in the prior art, path allocation considering the wavelength characteristic difference between cores in an optical transmission path has been studied, but as in this exemplary embodiment, no study has been made considering the wavelength characteristics of the transmission path itself. The reason is that, in general, optical amplifiers used in optical network systems have equalized wavelength characteristics as shown in FIG. 4, so the differences are small in the wavelength bands used (for example, the C band and the L band), and there is little need to consider the wavelength characteristics.

[0034] However, based on the inventors' unique findings, by considering the wavelength characteristics of the transmission path itself, the wavelength utilization efficiency in an optical network system can be improved. This is because an optical amplifier whose wavelength characteristics are not equalized has a wavelength region with a large amplification gain as shown in FIG. 5. In equalization, the wavelength region with a small amplification gain cannot be lifted, so the equalized wavelength characteristics as shown in FIG. 4 are obtained by attenuating the wavelength region with a large amplification gain by a frequency shaper so as to match the wavelength region with a small amplification gain. Therefore, it can be said that there is waste from the viewpoint of wavelength utilization efficiency. According to this exemplary embodiment, the above waste can be reduced and the frequency utilization efficiency can be further improved.

[0035] 〔Exemplary Embodiment 2〕 The second exemplary embodiment of the present invention will be described in detail with reference to the drawings. Components having the same functions as those described in the above exemplary embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0036] <Configuration of System and Apparatus> The configurations of the optical network system 1 and the optical network management apparatus 100 according to this exemplary embodiment are the same as those in the first exemplary embodiment, and the detailed configurations will be described in this exemplary embodiment.

[0037] (Multi-core optical fiber) Fig. 12 shows the structure of a 7-core multi-core optical fiber as an example of the structure of a multi-core optical fiber. Note that multi-core optical fibers are roughly classified into uncoupled multi-core optical fibers and coupled multi-core optical fibers, both of which have been developed.

[0038] Fig. 13 shows the structure of a 4-core uncoupled multi-core optical fiber as an example of the structure of an uncoupled multi-core optical fiber. An uncoupled multi-core optical fiber is an optical fiber that separates the cores and suppresses crosstalk between the cores. In an uncoupled multi-core optical fiber, each core can be used as an independent optical transmission path, so it is possible to directly utilize the optical communication technology developed for conventional single-core optical fibers.

[0039] Fig. 14 shows the structure of a 4-core coupled multi-core optical fiber as an example of the structure of a coupled multi-core optical fiber. A coupled multi-core optical fiber is an optical fiber that realizes a high core density by reducing the core spacing. In a coupled multi-core optical fiber, crosstalk occurs between the cores, so MIMO (Multi Input Multi Output) processing using a DIP (Digital Signal Processor) or the like is required at the optical receiver. Fig. 2 shows a structural diagram of 4-core uncoupled and coupled MCFs as an example, but in this patent, the uncoupled MCF is the target.

[0040] In this exemplary embodiment, an uncoupled multi-core optical fiber is used as the multi-core optical fiber constituting the optical transmission path 102.

[0041] (Optical Amplifier) Fig. 6 is a graph showing the wavelength characteristics of the optical amplifier 105 used in this exemplary embodiment. As shown in Fig. 6, the amplification gain of the optical amplifier 105 is larger in the first wavelength region Y than in the second wavelength region X.

[0042] In addition, in the present exemplary embodiment, it is preferable to use an optical amplifier 105 with unequalized wavelength characteristics, but it is not limited thereto, and an optical amplifier with equalized wavelength characteristics may also be used. Even for an optical amplifier with equalized wavelength characteristics, the wavelength characteristics are not completely constant with respect to the wavelength, and include a first wavelength region with a relatively large amplification gain and a second wavelength region with a relatively small amplification gain. Therefore, by applying the configuration of the present exemplary embodiment, the wavelength utilization efficiency can be improved.

[0043] (Node) FIG. 7 is a block diagram showing an example of the configuration of the node 101 used in the present exemplary embodiment. As shown in FIG. 7, each node 101 includes, for example, a node controller 201, a transponder 202, a wavelength switch 203, a fiber switch 204, a single-core optical fiber 205, a fan-in 206, a fan-out 208, a tap coupler 209, and a monitor 210, and is connected to a multi-core optical fiber 207 constituting the optical transmission path 102.

[0044] The fan-out 208 is connected to the multi-core optical fiber 207 constituting the optical transmission path 102, separates the outputs from each core of the multi-core optical fiber 207 on a core-by-core basis, and outputs them to the single-core optical fiber 205 respectively. The single-core optical fiber 205 receives the output from the fan-out 208. A fiber switch 204 is provided in the single-core optical fiber 205, and the path of the optical signal passing through the single-core optical fiber 205 is switched by switching the connection between the single-core optical fibers 205 sandwiching the fiber switch 204. The fan-in 206 bundles the outputs from the single-core optical fiber 205 and delivers them to the multi-core optical fiber 207.

[0045] The wavelength switch 203 receives a part of the output from the fiber switch 204 and performs switching in units of wavelengths. The transponder 202 transmits and receives optical signals.

[0046] A tap coupler 209 for branching some optical signals is attached to the single-core optical fiber 205, and the optical signals branched from the tap coupler 209 are input to the monitor 210. The node controller 201 controls the fiber switch 204 and the wavelength switch 203 according to the monitor information received from the monitor 210.

[0047] <Flow of the optical network management method> The flow of the optical network management method according to this exemplary embodiment will be described with reference to FIG. 8. FIG. 8 is a flowchart showing an example of the flow of the optical network management method according to this exemplary embodiment. As shown in FIG. 8, the optical network management method according to this exemplary embodiment includes at least steps S11 to S18.

[0048] In step S11 (core extraction process), the core extraction unit 11 extracts unused cores from among the cores of the optical fibers that constitute a plurality of optical transmission paths 102 connectable from the transmission node to the reception node. Note that the unused core means a core having an unused wavelength and usable for constituting a new path.

[0049] Next, in step S12 (core extraction process), the core extraction unit 11 extracts cores connectable from the transmission node to the reception node from the extracted unused cores.

[0050] Next, in step S13 (path assignment process), the path assignment unit 12 extracts unused wavelengths of the same wavelength that are common to each core connectable from the transmission node to the reception node, which are extracted by the core extraction unit 11.

[0051] Next, in step S14 (path assignment process), the path assignment unit 12 assigns a wavelength according to the attributes of the path.

[0052] In one aspect, the path allocation unit 12 preferentially allocates a path having a specific attribute to the first wavelength region Y. Also, in one aspect, the path allocation unit 12 may preferentially allocate a path having an attribute different from the specific attribute to the second wavelength region X. In this way, by distributing to the wavelength region Y with a large amplification gain and the wavelength region X with a small amplification gain according to the attribute of the path, the wavelength utilization efficiency in the optical network system 1 can be further improved.

[0053] In one aspect, the path allocation unit 12 may allocate wavelengths according to the bandwidth of the path. For example, as in the example shown in FIG. 6, the path allocation unit 12 may allocate a wide-bandwidth path such as 200 Gbps to the long-wavelength side wavelength region Y with good wavelength characteristics, and allocate a narrow-bandwidth path such as 100 Gbps to the short-wavelength side wavelength region X with poor wavelength characteristics.

[0054] Also, in one aspect, the path allocation unit 12 may allocate wavelengths according to the importance of the path. For example, the path allocation unit 12 may allocate a high-importance active path (a path in the active system) to the long-wavelength side wavelength region Y with good wavelength characteristics, and allocate a low-importance protection path (a path in the standby system) to the short-wavelength side wavelength region X with poor wavelength characteristics.

[0055] Also, in one aspect, the path allocation unit 12 may allocate wavelengths according to whether the path is an active system or a standby system. For example, the path allocation unit 12 may allocate an active path (a path in the active system) to the long-wavelength side wavelength region Y with good wavelength characteristics, and allocate a protection path (a path in the standby system) to the short-wavelength side wavelength region X with poor wavelength characteristics.

[0056] Furthermore, in one aspect, the path allocation unit 12 may allocate wavelengths by combining the above-described multiple criteria.

[0057] Next, in step S15 (node control process), the node control unit 13 controls the node controller 201 so as to realize the set path assigned by the path assignment unit 12. The node controller 201 controls the transponder 202 to match the wavelength transmitted and received by the transponder 202 with the wavelength assigned to the set path.

[0058] Next, in step S16 (node control process), the node controller 201 controls the wavelength switch 203 and the fiber switch 204 to accommodate the set path in a desired single-core optical fiber 205.

[0059] Next, in step S17 (node control process), the fan-in 206 accommodates the set path in a desired multi-core optical fiber 207.

[0060] Next, in step S18 (node control process), the node control unit 13 performs signaling to confirm the conduction of the set path. If signal passage is impossible, the process returns to step S14 to assign another wavelength to the path. If signal passage is confirmed, the control unit 10 completes the series of processes.

[0061] 〔Exemplary Embodiment 3〕 A third exemplary embodiment of the present invention will be described in detail with reference to the drawings. Components having the same functions as those described in the above exemplary embodiments are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0062] The configurations of the optical network system 1 and the optical network management device 100 according to this exemplary embodiment are the same as those of the above-described exemplary embodiments. In this exemplary embodiment, a configuration in which the path assignment unit 12 divides and assigns a path to a plurality of wavelengths will be described.

[0063] FIG. 9 is a diagram showing the relationship between the wavelength characteristics of the optical amplifier 105 used in this exemplary embodiment and the wavelengths to which paths are assigned. As shown in FIG. 9, instead of assigning a path to the wavelength Y1 in the first wavelength region Y, the path assignment unit 12 may divide the path into a plurality of wavelengths X1 and X2 and assign it to the second wavelength region Y2. By dividing the path in this way, for example, even a broadband path can be efficiently assigned. Hereinafter, a detailed example will be described.

[0064] FIG. 10 is a flowchart showing an example of the flow of the optical network management method according to this exemplary embodiment. As shown in FIG. 10, the optical network management method according to this exemplary embodiment includes at least steps S21 to S28.

[0065] Steps S21 to S23 are the same as steps S11 to S23 in the second exemplary embodiment, and steps S25 to S28 are the same as steps S15 to S18 in the second exemplary embodiment, so the description thereof will be omitted.

[0066] In step S24, the path assignment unit 12 divides the path according to the attributes of the path and assigns it to a plurality of wavelengths.

[0067] For example, in one aspect, when the attribute of the path is a specific attribute (for example, a broadband path) that should be preferentially assigned to the first wavelength region Y, and there is no wavelength in the first wavelength region Y in the free region common to each core extracted by the core extraction unit 11, the path assignment unit 12 may divide the path into two paths with half of the original bandwidth and assign them to the wavelengths X1 and X2 in the second wavelength region X.

[0068] Also, in one aspect, when the attribute of the path is a standby path and a working path has already been assigned to the wavelength Y1 in the first wavelength region Y, the path assignment unit 12 may divide the standby path (protection path) into two paths with half of the original bandwidth and assign them to the wavelengths X1 and X2 in the second wavelength region X.

[0069] 〔Exemplary Embodiment 4〕 A fourth exemplary embodiment of the present invention will be described in detail with reference to the drawings. Note that components having the same functions as those described in the above exemplary embodiments are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0070] The configurations of the optical network system 1 and the optical network management device 100 according to this exemplary embodiment are the same as those of the above-described exemplary embodiments. In this exemplary embodiment, the storage unit 20 stores information indicating the attributes of the path and information indicating the wavelength characteristics (wavelength characteristics of the optical amplifier 105) of the optical transmission path 102, and the path allocation unit 12 refers to this information to allocate a path. The configuration will be described.

[0071] In this exemplary embodiment, the path allocation unit 12 refers to the information indicating the attributes of the path stored in the storage unit 20 and the information indicating the wavelength characteristics (wavelength characteristics of the optical amplifier 105) of the optical transmission path 102 to allocate a path, thereby efficiently performing path allocation according to the attributes of the path in consideration of the wavelength characteristics of the optical transmission path 102. Hereinafter, detailed examples will be described.

[0072] FIG. 11 is a block diagram showing an example of the configuration of the optical network management device 100 in this exemplary embodiment. As shown in FIG. 11, the storage unit 20 stores a path attribute database that holds the bandwidth, distance, etc. of a path (active path or protection path), and a transmission path characteristic database that holds transmission characteristics such as the amplification gain and NF (Noise Figure) of each wavelength in the optical transmission path 102.

[0073] The path allocation unit 12 refers to the path attribute database and the transmission path characteristic database of the storage unit 20 to obtain the available bandwidth, wavelength, and number of wavelengths, and arranges the path based on the result.

[0074] Specifically, in step S2 of the first exemplary embodiment, step S14 of the second exemplary embodiment, and step S24 of the third exemplary embodiment, first, the path assignment unit 12 refers to the path attribute database stored in the storage unit 20 to obtain path attributes such as the bandwidth of the path, the importance of the path, the type of the path, and the distance of the path corresponding to the core extracted by the core extraction unit 11. Next, the path assignment unit 12 refers to the transmission line characteristic database to obtain transmission characteristics such as the amplification gain and NF corresponding to the wavelength common to each core extracted by the core extraction unit 11. Next, the path assignment unit 12 determines the bandwidth, wavelength, and number of wavelengths that can be assigned to each wavelength, and assigns a wavelength that matches according to the attributes of the path.

[0075] 〔Example of Realization by Software〕 Some or all of the functions of the optical network management device 100 may be realized by hardware such as an integrated circuit (IC chip), or may be realized by software.

[0076] In the latter case, the optical network management device 100 is realized by, for example, a computer that executes instructions of a program, which is software that realizes each function. An example of such a computer (hereinafter referred to as computer C) is shown in FIG. 15. Computer C includes at least one processor C1 and at least one memory C2. A program P for operating computer C as the optical network management device 100 is recorded in memory C2. In computer C, processor C1 reads and executes program P from memory C2, whereby each function of the optical network management device 100 is realized.

[0077] As the processor C1, for example, a CPU (Central Processing Unit), GPU (Graphic Processing Unit), DSP (Digital Signal Processor), MPU (Micro Processing Unit), FPU (Floating point number Processing Unit), PPU (Physics Processing Unit), a microcontroller, or a combination thereof can be used. As the memory C2, for example, a flash memory, HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof can be used.

[0078] Note that the computer C may further include a RAM (Random Access Memory) for expanding the program P during execution and temporarily storing various data. Also, the computer C may further include a communication interface for transmitting and receiving data to and from other devices. Further, the computer C may further include an input / output interface for connecting input / output devices such as a keyboard, mouse, display, and printer.

[0079] Also, the program P can be recorded on a non-transitory tangible recording medium M readable by the computer C. As such a recording medium M, for example, a tape, disk, card, semiconductor memory, or programmable logic circuit can be used. The computer C can obtain the program P via such a recording medium M. Also, the program P can be transmitted via a transmission medium. As such a transmission medium, for example, a communication network or broadcast wave can be used. The computer C can also obtain the program P via such a transmission medium.

[0080] 〔Supplementary Note 1〕 The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope indicated in the claims. For example, embodiments obtained by appropriately combining the technical means disclosed in the above-described embodiments are also included in the technical scope of the present invention.

[0081] [Supplementary Note 2] Some or all of the above-described embodiments may also be described as follows. However, the present invention is not limited to the aspects described below.

[0082] (Supplementary Note 1) An optical network management device that assigns a path from a transmission node to a reception node in an optical network system including a multi-core optical fiber, a core extraction unit that extracts cores constituting the path; a path assignment unit that selects a wavelength to assign the path according to the attribute of the path, and an optical amplifier is attached to the multi-core optical fiber, the amplification gain of the optical amplifier increases more in a first wavelength region than in a second wavelength region, wherein the path assignment unit preferentially assigns the path having a specific attribute to the first wavelength region. An optical network management device.

[0083] According to the above configuration, it is possible to perform path assignment according to the attribute of the path in consideration of the wavelength characteristics of the optical transmission path, and as a result, improve the wavelength utilization efficiency in an optical network system including a multi-core optical fiber.

[0084] (Supplementary Note 2) The optical network management device according to Supplementary Note 1, wherein the path assignment unit preferentially assigns the path having an attribute different from the specific attribute to the second wavelength region.

[0085] According to the above configuration, by allocating wavelengths to a wavelength region with a large amplification gain and a wavelength region with a small amplification gain according to the attributes of the path, it is possible to further improve the wavelength utilization efficiency in an optical network system including a multi-core optical fiber.

[0086] (Appendix 3) The attribute of the path is the optical network management device described in Appendix 1 or 2, including the bandwidth of the path.

[0087] According to the above configuration, it becomes possible to perform path allocation according to the bandwidth of the path while considering the wavelength characteristics of the optical transmission path.

[0088] (Appendix 4) The attribute of the path is the optical network management device described in any one of Appendices 1 to 3, including the importance of the path.

[0089] According to the above configuration, it becomes possible to perform path allocation according to the importance of the path while considering the wavelength characteristics of the optical transmission path.

[0090] (Appendix 5) The attribute of the path is the optical network management device described in any one of Appendices 1 to 4, including whether the path is an active system or a standby system.

[0091] According to the above configuration, it becomes possible to perform path allocation according to whether the path is an active system or a standby system while considering the wavelength characteristics of the optical transmission path.

[0092] (Appendix 6) The path allocation unit divides the path into a plurality of wavelengths and preferentially allocates them to the second wavelength region, which is the optical network management device described in any one of Appendices 1 to 5.

[0093] According to the above configuration, by dividing the path, it becomes possible to allocate efficiently even a broadband path, for example.

[0094] (Appendix 7) A storage unit storing information indicating the attributes of the path and information indicating the wavelength characteristics of the optical amplifier is provided. The path allocation unit refers to the information stored in the storage unit and allocates the path. The optical network management device according to any one of Appendices 1 to 6.

[0095] According to the above configuration, by referring to the information indicating the attributes of the path and the information indicating the wavelength characteristics of the optical amplifier, it is possible to efficiently perform path allocation according to the attributes of the path in consideration of the wavelength characteristics of the optical transmission path.

[0096] (Appendix 8) The optical network management device according to any one of Appendices 1 to 7, An optical transmission path including the multi-core optical fiber, A node connected by the optical transmission path, and an optical network system.

[0097] According to the above system, the same effect as that of Appendix 1 is achieved.

[0098] (Appendix 9) An optical network management method for allocating a path from a transmission node to a reception node in an optical network system including a multi-core optical fiber, Extracting the cores constituting the path, Selecting a wavelength for allocating the path according to the attributes of the path, An optical amplifier is attached to the multi-core optical fiber, The amplification gain of the optical amplifier increases in a first wavelength region more than in a second wavelength region, Selecting the wavelength for allocating the path includes preferentially allocating the path having specific attributes to the first wavelength region. The optical network management method.

[0099] According to the above method, the same effect as that of Appendix 1 is achieved.

[0100] (Appendix 10) An optical network management program for causing a computer to function as an optical network management apparatus that assigns a path from a transmission node to a reception node in an optical network system including a multi-core optical fiber, the computer being caused to function as a core extraction unit that extracts cores constituting the path, and function as a path assignment unit that selects a wavelength to which the path is assigned according to the attribute of the path, wherein an optical amplifier is attached to the multi-core optical fiber, wherein an amplification gain of the optical amplifier increases more in a first wavelength region than in a second wavelength region, and the path assignment unit preferentially assigns the path having a specific attribute to the first wavelength region. An optical network management program.

[0101] According to the above program, the same effects as those of Supplementary Note 1 are achieved.

[0102] 〔Supplementary Note 3〕 Part or all of the above-described exemplary embodiments can also be expressed as follows.

[0103] An optical network management apparatus that assigns a path from a transmission node to a reception node in an optical network system including a multi-core optical fiber includes at least one processor, and the processor executes a core extraction process for extracting cores constituting the path and a path assignment process for selecting a wavelength to which the path is assigned according to the attribute of the path. An optical amplifier is attached to the multi-core optical fiber, an amplification gain of the optical amplifier increases more in a first wavelength region than in a second wavelength region, and the path assignment process preferentially assigns the path having a specific attribute to the first wavelength region. An optical network management apparatus.

[0104] Incidentally, this optical network management device may further include a memory, and a program for causing the processor to execute the core extraction process and the path assignment process may be stored in this memory. Further, this program may be recorded on a non-transitory tangible computer-readable recording medium.

Explanation of Signs

[0105] 1 Optical network system 10 Control unit 11 Core extraction unit 12 Path assignment unit 13 Node control unit 20 Storage unit 30 Network interface 100 Optical network management device 101 Node 102 Optical transmission path 103 Ring 104 Connection link 105 Amplifier 201 Node controller 202 Transponder 203 Wavelength switch 204 Fiber switch 205 Single-core optical fiber 206 Fan-in 207 Multi-core optical fiber 208 Fan-out 209 Tap coupler 210 Monitor

Claims

1. An optical network management device that assigns a path from a transmitting node to a receiving node in an optical network system including a multi-core optical fiber, comprising: a core extraction unit that extracts cores constituting the path; a path assignment unit that selects a wavelength to assign the path according to the attributes of the path, wherein an optical amplifier is attached to the multi-core optical fiber, the amplification gain of the optical amplifier increases in a first wavelength region more than in a second wavelength region, the path assignment unit preferentially assigns the path having specific attributes to the first wavelength region, when the attribute of the path is a specific attribute that should be preferentially assigned to the first wavelength region and there is no wavelength in the first wavelength region in the free space common to each core extracted by the core extraction unit, the path assignment unit divides the path into a plurality and assigns different wavelengths included in the second wavelength region to each of the divided paths. An optical network management device.

2. The optical network management device according to claim 1, wherein the path assignment unit preferentially assigns the path having an attribute different from the specific attribute to the second wavelength region.

3. The optical network management device according to claim 1 or 2, wherein the attribute of the path includes the bandwidth of the path.

4. The optical network management device according to any one of claims 1 to 3, wherein the attribute of the path includes the importance of the path.

5. The optical network management device according to any one of claims 1 to 4, wherein the attribute of the path includes whether the path is an active system or a standby system.

6. comprising a storage unit storing information indicating the attribute of the path and information indicating the wavelength characteristics of the optical amplifier, The optical network management device according to any one of claims 1 to 5, wherein the path assignment unit assigns the path with reference to the information stored in the storage unit.

7. An optical network management device according to any one of claims 1 to 6, an optical transmission path including the multi-core optical fiber, and nodes connected by the optical transmission path. An optical network system.

8. An optical network management method for assigning a path from a transmitting node to a receiving node in an optical network system including a multi-core optical fiber, comprising: extracting cores constituting the path, including selecting a wavelength to which the path is to be assigned according to the attribute of the path; an optical amplifier is attached to the multi-core optical fiber; the amplification gain of the optical amplifier increases more in a first wavelength region than in a second wavelength region; selecting the wavelength to which the path is to be assigned includes preferentially assigning the path having a specific attribute to the first wavelength region; when the attribute of the path is a specific attribute that should be preferentially assigned to the first wavelength region, and when there is no wavelength in the first wavelength region in the free space common to each of the extracted cores, selecting the wavelength to which the path is to be assigned includes dividing the path into a plurality of paths and assigning different wavelengths included in the second wavelength region to the divided paths respectively, an optical network management method.

9. An optical network management program for causing a computer to function as an optical network management apparatus that assigns a path from a transmission node to a reception node in an optical network system including a multi-core optical fiber, the computer being caused to: function as a core extraction unit that extracts cores constituting the path, and function as a path assignment unit that selects a wavelength to which the path is to be assigned according to the attribute of the path; an optical amplifier is attached to the multi-core optical fiber; the amplification gain of the optical amplifier increases more in a first wavelength region than in a second wavelength region; the path assignment unit preferentially assigns the path having a specific attribute to the first wavelength region; when the attribute of the path is a specific attribute that should be preferentially assigned to the first wavelength region, and when there is no wavelength in the first wavelength region in the free space common to each of the cores extracted by the core extraction unit, the path assignment unit divides the path into a plurality of paths and assigns different wavelengths included in the second wavelength region to the divided paths respectively, an optical network management program.

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