Processing device and processing method

Abstract

In an optical communication network APN provided with a plurality of nodes N and a plurality of fibers F connecting pairs of the nodes N, a processing device 1 is provided with: a storage device that stores configuration data 11 specifying the order of the plurality of nodes N connected by the fibers F, and a specific node from among the plurality of nodes N that is a conversion node for converting wavelengths, and wavelength data 12 specifying wavelengths available in fibers F connecting pairs of adjacent nodes; an acquisition unit 21 that acquires an identifier of a start node NS and an identifier of an end node NT of a newly established optical path; and a selection unit 22 that, by referencing to the configuration data 11 and the wavelength data 12, selects a wavelength available in a section from the start node NS to the conversion node and unavailable in an adjacent section on the opposite side of the conversion node with respect to the start node NS.

Description

Processing device and processing method

[0001] The present disclosure relates to a processing device and a processing method.

[0002] There is an all-photonics network (see Non-Patent Document 1). The all-photonics network enables further increases in speed and capacity of communication networks. The all-photonics network is expected to be able to handle the currently rapidly increasing communication traffic.

[0003] Wavelength conversion technology can be used in all-photonics networks, which is expected to expand wavelength utilization and improve efficiency.

[0004] Makoto Kaneko and six others, "New System Architecture for Realizing All-Photonics Networks," May 2021, [online], May 2021, IEICE Journal, Vol. 104 No. 5, Institute of Electronics and Information Engineers, [Retrieved August 26, 2024], Internet <URL: https: / / app.journal.ieice.org / trial / 104_5 / k104_5_471 / index.html>

[0005] However, wavelength accommodation efficiency may be reduced depending on the wavelength of the optical signal before and after using the wavelength conversion technique.

[0006] The present disclosure has been made in consideration of the above circumstances, and an object of the present disclosure is to provide a technology that can improve wavelength accommodation efficiency in an all-photonics network.

[0007] A processing device of one aspect of the present disclosure is provided in an optical communication network having a plurality of nodes and a plurality of fibers connecting two nodes, and includes a memory device that stores the order of the plurality of nodes connected by the fibers, configuration data that identifies a conversion node among the plurality of nodes that converts wavelengths, and wavelength data that identifies wavelengths that can be used in the fiber connecting two adjacent nodes, an acquisition unit that acquires an identifier of the start node and an identifier of the end node of a newly opened optical path, and a selection unit that refers to the configuration data and the wavelength data to select wavelengths that can be used in the section from the start node to the conversion node and that cannot be used in the adjacent section on the opposite side of the conversion node relative to the start node.

[0008] In one aspect of the processing method of the present disclosure, a computer stores in a storage device the order of the nodes connected by the fibers in an optical communication network having a plurality of nodes and a plurality of fibers connecting two nodes, configuration data identifying a conversion node among the plurality of nodes that converts wavelengths, and wavelength data identifying wavelengths available in the fibers connecting two adjacent nodes, the computer obtains an identifier of the start node and an identifier of the end node of a newly opened optical path, and the computer refers to the configuration data and the wavelength data to select wavelengths that are available in the section from the start node to the conversion node and that are unavailable in the adjacent section on the opposite side of the conversion node of the start node.

[0009] According to the present disclosure, it is possible to provide a technology that can improve wavelength accommodation efficiency in an all-photonics network.

[0010] FIG. 1 is a diagram illustrating functional blocks of a processing device according to the present disclosure. FIG. 2 is a diagram illustrating the configuration of an optical communication network. FIG. 3 is a diagram illustrating an example of wavelengths used in the optical communication network. FIG. 4 is a diagram illustrating an example of wavelengths converted by a conversion node. FIG. 5 is a diagram illustrating wavelength conversion and wavelength band conversion. FIG. 6 shows bands that can be transmitted and received according to fiber standards. FIG. 7 is a flowchart illustrating an example of processing in the processing device. FIG. 8 is a flowchart illustrating an example of processing for selecting a target section between a start node and a conversion node. FIG. 9 is a diagram illustrating the hardware configuration of a computer used in the processing device.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description of the drawings, the same parts are designated by the same reference numerals and the description thereof will be omitted.

[0012] As shown in Fig. 1, when a new optical path is set in an optical communication network APN, the processing device 1 appropriately selects wavelengths before and after wavelength conversion to improve wavelength accommodation efficiency. For example, the processing device 1 selects the wavelength of a new optical path for a given wavelength so that no section of an existing optical path will have an unused wavelength. In the present disclosure, the technology for converting wavelengths may include technology for converting wavelength bands. A wavelength band includes multiple wavelengths.

[0013] 2 , the optical communication network APN includes a plurality of nodes N and a plurality of fibers F connecting two nodes N. The optical communication network APN includes nodes N1, N2, N3, N4, N5, and N6, and fibers F1, F2, F3, F4, and F5 connecting the nodes. When there is no need to particularly distinguish between the nodes N1, N2, N3, N4, N5, and N6, they may be referred to as nodes N. The fibers F1, F2, F3, F4, and F5 may be referred to as fibers F.

[0014] The optical communication network APN is an all-photonics network (APN), which realizes communication between terminals through a wavelength network provided by optical paths.

[0015] 3, the first fiber F1, the second fiber F2, and the third fiber F3 are SMF (Single Mode Fiber), and the fourth fiber F4 and the fifth fiber F5 are DSF (Dispersion Shifted Fiber).

[0016] The first node N1 to the fourth node N4 use wavelengths in the C-band. The fourth node N4 to the sixth node N6 use wavelengths in the L-band. The C-band has wavelengths λ1, λ2, λ3, and λ4. The L-band has wavelengths λ5, λ6, λ7, and λ8.

[0017] In the optical communication network APN, the fourth node N4 and the sixth node N6 are conversion nodes having a wavelength conversion function. As shown in Fig. 4, the fourth node N4 converts each wavelength in the C-band band received to each wavelength in the L-band band and transmits the converted wavelengths, and converts each wavelength in the L-band band received to each wavelength in the C-band band and transmits the converted wavelengths.

[0018] In the present disclosure, wavelength conversion refers to converting one wave of a predetermined wavelength of an optical signal into one wave of an arbitrary wavelength, as shown in Fig. 5(a). In this case, the wavelength of the converted signal may be in the C-band, the same as the source signal, or in the L-band, a different wavelength from the source signal.

[0019] In the present disclosure, wavelength conversion may include waveband conversion, which converts multiple wavelengths together. In waveband conversion, the relative relationship between the multiple wavelengths is fixed. Waveband conversion converts a bundle of multiple wavelengths into another bundle of wavelengths by shifting them, as shown in FIG. 5(b).

[0020] Figure 6 explains the international standards adopted for each band. The international standards define the fiber specifications used in each band. As shown in Figure 5, the fiber specifications are SMF, DSF, and CSF (Cutoff Shifted Fiber). The fiber specifications define the bands in which transmission and reception is possible.

[0021] 1 includes configuration data 11, wavelength data 12, characteristic data 13, order data 16, and selected wavelength data 17, and functions of an acquisition unit 21, a selection unit 22, and a setting unit 23. Each piece of data is stored in a storage device such as a memory 902 or a storage 903. Each function is implemented in a CPU 901.

[0022] The configuration data 11 specifies the order of the multiple nodes N connected by the fiber F. The configuration data 11 further specifies a conversion node that converts wavelengths among the multiple nodes N. In the present disclosure, the configuration data 11 specifies the order of the nodes N shown in FIG. 2. The configuration data 11 specifies that the fourth node N4 and the sixth node N6 have a function of converting wavelengths.

[0023] The wavelength data 12 identifies wavelengths available for use in a fiber F connecting two adjacent nodes N. The wavelength data 12, for example, associates an identifier of the fiber F with wavelengths available for use in that fiber F. Here, the identifier of the fiber F is linked to a section identified by the two nodes N to which that fiber F is connected. Alternatively, the wavelength data 12 associates a flag indicating the usage status for each wavelength provided by that fiber F with the identifier of the fiber F. The usage status may be, for example, whether the wavelength is already assigned to an optical path and in use, or whether it is available for use in a new optical path. The wavelength data 12 may be any data as long as it can identify wavelengths available for use in a new optical path in each section of the optical communication network APN and in each fiber F.

[0024] The characteristic data 13 is data that is referenced to confirm the reachability of an optical signal. The characteristic data 13 includes the characteristics of the fiber F and the characteristics of the components for connecting the fiber F. For example, the characteristic data 13 associates loss information and chromatic dispersion information for each wavelength with each fiber F. Data for confirming the reachability of an optical signal is identified in advance by measurement or the like. The characteristic data 13 may include data other than the items exemplified here.

[0025] The order data 16 is data specifying the conditions of a newly established optical path. The order data 16 includes at least an identifier of a start node NS and an identifier of a end node NT of the optical path. At least one conversion node is included between the start node NS and the end node NT.

[0026] In the present disclosure, the starting node NS is the third node N3, the ending node NT is the sixth node N6, and the fourth node N4 and the sixth node N6 are included as conversion nodes between the starting node NS and the ending node NT.

[0027] The selected wavelength data 17 specifies the wavelength selected by the selector 22 for a newly established optical path. The selected wavelength data 17 associates a section specified by the identifiers of two nodes N with the wavelength selected in that section. The section included in the selected wavelength data 17 is specified by two nodes N out of one start node NS, one or more conversion nodes, and one end node NT.

[0028] The acquiring unit 21 acquires the order data 16 .

[0029] The selector 22 selects a wavelength to be used between the start node NS and the end node NT specified by the order data 16 .

[0030] 5(a) and includes one conversion node between the start node NS and the end node NT, the selector 22 assigns wavelengths to each of the section between the start node NS and the conversion node and the section from the conversion node to the end node. If two or more conversion nodes are included between the start node NS and the end node NT, the selector 22 also assigns wavelengths to the sections between adjacent conversion nodes.

[0031] The selector 22 identifies conversion nodes in the section from the start node NS to the end node NT by referring to the configuration data 11. The selector 22 first selects wavelengths in the section from the start node NS to the conversion node closest to the start node.

[0032] The process of selecting wavelengths in the section from the start node NS to the conversion node closest to the start node will be described. The selector 22 refers to the wavelength data 12 and selects wavelengths that are available in the section from the start node NS to the conversion node and are unavailable in the adjacent section on the opposite side of the conversion node of the start node NS. Here, the adjacent section is the section that starts from the start node NS and is adjacent in the direction going back in the opposite direction to the section where the optical path is opened.

[0033] 3 will be described. The selector 22 refers to the configuration data 11 and identifies the fourth node N4 as a conversion node in the section from the start node NS to the end node NT. The selector 22 refers to the wavelength data 12 and identifies wavelengths λ1, λ2, and λ4 as available wavelengths in the section between the third node N3, which is the start node NS, and the fourth node N4, which is the conversion node.

[0034] The selector 22 further identifies the section between the second node N2 and the third node N3 as adjacent sections on the opposite side of the conversion node with respect to the source node NS. The selector 22 identifies the wavelengths λ1 and λ3 as wavelengths that cannot be used in the section between the second node N2 and the third node N3.

[0035] In the section between the third node N3, which is the start node NS, and the fourth node N4, which is the conversion node, the selector 22 selects wavelength λ1 as a wavelength that is available in the section from the start node NS to the conversion node and that is unavailable in the adjacent section on the opposite side of the conversion node from the start node NS. Because the wavelength is unavailable in the adjacent section, each optical path is assigned without gaps at wavelength λ1 from the first node N1 to the fourth node N4, so there is no waste.

[0036] If there are no wavelengths that are unavailable in the adjacent section on the opposite side of the conversion node for the starting node NS, specifically, if there are one or more available wavelengths, the selection unit 22 selects wavelengths that are unavailable in other adjacent sections that are adjacent to the opposite side of the starting node NS for the adjacent section.

[0037] 3, it is assumed that wavelength λ1 is in use between the third node N3 and the fourth node N4. In this case, the selector 22 identifies wavelengths λ2 and λ4 as available wavelengths in the section between the third node N3, which is the source node NS, and the fourth node N4, which is the conversion node.

[0038] The adjacent section is a section in the opposite direction from the section where the optical path is opened, and is the section between the second node N2 and the third node N3. If there are no wavelengths that are available between the start node NS and the conversion node but are unavailable in the adjacent section, the selector 22 further selects wavelengths that are unavailable in the adjacent section between the first node N1 and the second node N2. In the example shown in FIG. 3 , the selector 22 selects wavelength λ2. Wavelength λ2 is assigned to an existing optical path from the first node N1 to the second node N2, and is considered for assignment to a new optical path from the third node N3 to the fourth node N4. For wavelength λ2, although an optical path is not assigned in one section from the second node N2 to the third node N3, the unassigned section is minimal, so there is little waste.

[0039] If there are no unavailable wavelengths in the sections adjacent to the adjacent section, the selector 22 selects wavelengths that are not used in other sections. Here, the other sections are sections going back from the start node NS to search for unavailable wavelengths, and are the sections adjacent to the start node NS and the sections adjacent to the adjacent sections. In this disclosure, the number of sections going back from the start node NS to search for unavailable wavelengths is set to two, but this is not limited to this. The number of sections going back from the start node NS may be set in advance.

[0040] 3, the adjacent section of the start node NS and the adjacent section of the adjacent section are the sections of the first node N1 and the third node N3. In this section, the wavelength λ4 is not used. The selector 22 selects the wavelength λ4 for the section of the conversion node of the start node NS.

[0041] After selecting the wavelength from the start node NS to the conversion node, the selector 22 then selects a wavelength for each section up to the end node NT. Here, when the conversion node converts to an arbitrary wavelength as shown in Fig. 5(a), the selector 22 selects a wavelength for each section up to the end node NT according to a predetermined rule. Each section is a section between the start node NS and the end node NT, that is, a section between two adjacent conversion nodes from the conversion node closest to the start node NS to the conversion node closest to the end node NT, and a section from the conversion node closest to the end node NT to the end node NT.

[0042] The selector 22 selects wavelengths for each section from the start node NS to the end node NT, and stores the wavelengths selected for each section in the selected wavelength data 17 .

[0043] 5(b), when a conversion node converts a bundle of multiple wavelengths into another bundle of wavelengths by shifting, the selector 22 only needs to select wavelengths from the start node NS to the nearest conversion node, and does not need to select wavelengths for the section from the conversion node to the end node NT. This is because the conversion node converts the wavelength of the input optical signal by shifting according to a predetermined rule.

[0044] The setting unit 23 sets an optical path from the start node NS to the end node NT at the selected wavelength when the optical signal reaches from the start node NS to the end node NT based on the loss characteristics of the optical signal at the selected wavelength with reference to the characteristic data 13. Here, the setting unit 23 may confirm that the optical signal reaches from the start node NS to the end node NT based on the loss characteristics of the optical signal at the selected wavelength in each section from the start node NS to the end node NT.

[0045] The setting unit 23 determines whether the optical signal transmitted by the starting node NS will reach the ending node NT by referring to the loss information at the wavelength specified by the selected wavelength data 17, the wavelength dispersion information, the distance of each section, the number of nodes passed through, etc. for each fiber F used in each section from the starting node NS to the ending node NT.

[0046] If the wavelength does not reach the destination node NS, the setting unit 23 instructs the selection unit 22 to select a new wavelength. If the wavelength reaches the destination node NS, the setting unit 23 sets an optical path from the start node NS to the end node NT at the selected wavelength for the optical communication network APN.

[0047] (Processing Method) A processing method according to the present disclosure will be described with reference to FIG.

[0048] In step S1, the processing device 1 acquires the start node NS and the end node NT of the optical path to be newly established.

[0049] In step S2, the processing device 1 selects wavelengths for each section from the start node NS to the end node NT.

[0050] In step S3, the processing device 1 determines whether the optical signal reaches from the start node NS to the end node NT using the wavelengths selected for each section in step S2. If it is determined that the optical signal does not reach the start node NS and the end node NT, the processing device 1 selects wavelengths again for each section from the start node NS to the end node NT.

[0051] If they do reach the destination, in step S4 the processing device 1 sets up an optical path for each wavelength selected in step S2.

[0052] An example of the selection process shown in Fig. 7 will be described with reference to Fig. 8. Fig. 8 shows a case where the target section for selecting wavelengths is between the start node and the conversion node closest to the start node.

[0053] In step S51, the processing device 1 identifies wavelengths that can be used in the target section.

[0054] In step S52, the processing device 1 identifies wavelengths that are unavailable in sections adjacent to the target section. In step S53, the processing device 1 determines whether there are any wavelengths that are included in both the wavelengths identified in step S51 and the wavelengths identified in step S52.

[0055] If there is a wavelength included in both the wavelength specified in step S51 and the wavelength specified in step S52, that wavelength is selected in step S54 and the process ends. If there is no wavelength included in both the wavelength specified in step S51 and the wavelength specified in step S52, the process proceeds to step S55.

[0056] In step S55, the processing device 1 identifies wavelengths that are unavailable in the section adjacent to the section adjacent to the target section. In step S56, the processing device 1 determines whether there are any wavelengths that are included in both the wavelengths identified in step S51 and the wavelengths identified in step S55.

[0057] If there is a wavelength included in both the wavelength specified in step S51 and the wavelength specified in step S55, that wavelength is selected in step S57 and the process ends. If there is no wavelength included in both the wavelength specified in step S51 and the wavelength specified in step S55, the process proceeds to step S58.

[0058] In step S58, the processing device 1 identifies wavelengths available in adjacent sections of the target section and adjacent sections of the adjacent sections. In step S59, the processing device 1 selects wavelengths included in both the wavelengths identified in step S51 and the wavelengths identified in step S58.

[0059] The processing device 1 according to the present disclosure selects a wavelength to be used in a new optical path so as to set the new optical path using that wavelength in a section close to a section used by an existing optical path using that wavelength, thereby improving the wavelength accommodation efficiency in an all-photonics network.

[0060] The processing device 1 according to the present disclosure described above is, for example, a general-purpose computer system including a CPU (Central Processing Unit, processor) 901, a memory 902, a storage 903 (HDD: Hard Disk Drive, SSD: Solid State Drive), a communication device 904, an input device 905, and an output device 906. In this computer system, the CPU 901 executes a program loaded on the memory 902, thereby realizing each function of the processing device 1.

[0061] The processing device 1 may be implemented by one computer or by multiple computers, or may be a virtual machine implemented on a computer.

[0062] The program of the processing device 1 can be stored in a computer-readable recording medium such as a HDD, SSD, USB (Universal Serial Bus) memory, CD (Compact Disc), DVD (Digital Versatile Disc), or can be distributed via a network. The computer-readable recording medium is, for example, a non-transitory recording medium.

[0063] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the present disclosure.

[0064] REFERENCE SIGNS LIST 1 Processing device 11 Configuration data 12 Wavelength data 13 Characteristics data 16 Order data 17 Selected wavelength data 21 Acquisition unit 22 Selection unit 23 Setting unit 901 CPU 902 Memory 903 Storage 904 Communication device 905 Input device 906 Output device APN Optical communication network F Fiber N Node NS Source node NT End node

Claims

1. A processing device comprising: a storage device for storing, in an optical communication network having a plurality of nodes and a plurality of fibers connecting two nodes, the order of the plurality of nodes connected by the fibers, configuration data that identifies a conversion node among the plurality of nodes that converts wavelengths, and wavelength data that identifies wavelengths that can be used in the fiber connecting two adjacent nodes; an acquisition unit that acquires the identifier of the start node and the identifier of the end node of a newly established optical path; and a selection unit that refers to the configuration data and the wavelength data to select wavelengths that can be used in the section from the start node to the conversion node and that cannot be used in the adjacent section on the opposite side of the conversion node relative to the start node.

2. The processing device according to claim 1, wherein the selection unit, if there is no wavelength that is unavailable in the adjacent section, selects a wavelength that is unavailable in another adjacent section adjacent to the opposite side of the starting node for the adjacent section.

3. The processing device according to claim 1, further comprising a setting unit that selects a wavelength for each section from the start node to the end node, and that sets an optical path from the start node to the end node at the selected wavelength when the optical signal reaches the end node from the start node based on the loss characteristics of the optical signal at the selected wavelength.

4. A processing method in which a computer stores in a storage device the order of the nodes connected by the fibers, configuration data that identifies a conversion node among the nodes that converts wavelengths, and wavelength data that identifies wavelengths that can be used in the fibers connecting two adjacent nodes in an optical communication network having a plurality of nodes and a plurality of fibers connecting two nodes, the computer obtains an identifier for the start node and an identifier for the end node of a newly established optical path, and the computer refers to the configuration data and the wavelength data to select wavelengths that can be used in the section from the start node to the conversion node and that cannot be used in the adjacent section on the opposite side of the conversion node of the start node.

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