Transmission network management device

Abstract

The purpose of the present invention is to manage new information necessary for path design when performing path design of an optical transmission network capable of handling multiple bands even in an environment in which a mixture of a plurality of types of optical fibers are present, and thereby increasing the scale and economic potential of the network.　To this end, disclosed herein is a transmission network management device for managing information necessary for path design when performing path design of a transmission network capable of handling multiple bands, the transmission network management device including: a physical topology information management unit that manages physical topology information used for estimating transmission quality in the path design; and a logical topology information management unit that is used for route design and wavelength design in the path design and manages logical topology information, including cost values indicating that it is easy or difficult to be selected from among a plurality of types of optical fibers of different wavelength bands, during the route design.

Description

Transmission network management equipment

[0001] The present disclosure relates to a technology for managing new information required for path design when designing paths (transmission routes) in an optical transmission network that can accommodate multiple bands.

[0002] In conventional optical transmission networks, optical transmission devices such as ROADM (Reconfigurable Optical Add / Drop Multiplexer) or APN (All-Photonics Network)-G / I support a single wavelength band (e.g., L-band) for optical communications, and it is assumed that the optical fibers to be installed also support this wavelength band.

[0003] The topology information of an optical transmission network is composed of node information and link information, and the link information only needs to manage characteristic values ​​such as communication distance or loss (transmission loss) through optical fiber. Furthermore, in transmission path design (transmission line design), the topology information is used to select the transmission path route and the optical fiber wavelength band, and to confirm whether the transmission quality is satisfied. As a means for estimating transmission quality, it is assumed that tools provided by each vendor or the open source software GNPy (Non-Patent Documents 1 and 2) can be used.

[0004] Fig. 9 is a diagram showing an example of a transmission path in a general optical transmission network. Fig. 9 shows a case in which multiple optical transmission devices 90a to 90d are installed between optical terminal devices 80a and 80b, such as transponders or APN-Ts. Also, in Fig. 9, the transmission paths are indicated by dashed lines. The transmission paths are optical wavelength paths established between the optical terminal devices, and are communication paths that transmit optical signals at specific frequencies within a WDM (Wavelength Division Multiplexing) grid.

[0005] To expand transmission line capacity in the future, it will be necessary to expand the wavelength bands used to multiple bands (for example, the C+L band (C band and L band)) (Non-Patent Document 3). In such cases, it is necessary to consider the characteristics of the optical fiber that makes up the link. For example, single-mode fiber (SMF), which is suitable for high-quality and stable communication, supports the C+L band, while dispersion-shifted single-mode optical fiber (DSF), which is suitable for long-distance transmission, supports the L band. The available wavelength bands differ depending on the type of optical fiber.

[0006] GNPy Optical Route Planning Library<https: / / gnpy.readthedocs.io / en / master / > GNPy: An open source application for physical layer aware open optical networks. C+L band CDC-ROADM for high capacity network flexibility.<https: / / journal.ntt.co.jp / wp-content / uploads / 2022 / 05 / nttjnl5002_20220601.pdf>

[0007] However, when the optical fiber that makes up a link is made up of multiple types of optical fiber spliced ​​together, it is necessary to manage the optical fiber information and then map it with the link information, but conventional transmission network management cannot adequately handle this.

[0008] The present disclosure aims to achieve increased capacity and economy in transmission networks by managing new information required for path design when designing paths for optical transmission networks that can support multiple bands, even in environments where multiple types of optical fibers are mixed.

[0009] In order to achieve the above-mentioned objective, the present disclosure provides a transmission network management device that manages information necessary for path design when designing paths in a transmission network that is compatible with multiple bands, the transmission network management device having: a physical topology information management unit that manages physical topology information used to estimate transmission quality in the path design; and a logical topology information management unit that manages logical topology information used for route design and wavelength design in the path design, the logical topology information including cost values ​​that indicate the ease or difficulty of selection from multiple types of optical fiber that are in different wavelength bands when designing the route.

[0010] As described above, according to the present disclosure, even in an environment where multiple types of optical fiber are mixed, when designing paths for a transmission network that can support multiple bands, by managing new information required for path design, it is possible to achieve an increase in capacity and economy of the transmission network.

[0011] 1 is an overall configuration diagram of a communication system according to an embodiment. FIG. 2 is an electrical hardware configuration diagram of a transmission network management device according to an embodiment. FIG. 3 is a functional configuration diagram of a transmission network management device. FIG. 4 is a diagram showing the relationship between logical topology and physical topology. FIG. 5 is a diagram showing optical fiber information managed by a fiber information management unit. FIG. 6 is a diagram showing fiber path information managed by a fiber path information management unit. FIG. 7 is a diagram showing functional component information managed by a functional component information management unit. FIG. 8 is a diagram showing functional component connection information managed by a functional component connection information management unit. FIG. 9 is a diagram showing link information managed by a link information management unit. FIG. 10 is a diagram showing optical transmission device information managed by an optical transmission device information management unit. FIG. 11 is a flowchart showing processing for managing new information required for path design. FIG. 12 is a flowchart showing processing for path design. FIG. 13 is a diagram showing an example of a transmission path in a general optical transmission network.

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments shown below, and various modifications are possible within the scope of the technical concept of the present invention. Since the drawings are intended to conceptually explain the present invention, dimensions, ratios, or numbers may be exaggerated or simplified as necessary to facilitate understanding.

[0013] [System Configuration of the Embodiment] First, the overall configuration of a communication system according to the embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing the overall configuration of a communication system according to the embodiment.

[0014] 1, a communication system 10 according to this embodiment is configured by a transmission network management device 30, multiple optical terminal devices 80a and 80b, and multiple optical transmission devices 90a to 90d. The optical terminal devices 80a and 80b are collectively referred to as "optical terminal device 80." The optical transmission devices 90a to 90d are collectively referred to as "optical transmission device 90."

[0015] The transmission network management device 30 is configured with one or more computers. When the transmission network management device 30 is configured with multiple computers, it may be referred to as a "transmission network management device" or a "transmission network management system." The transmission network management device 30 manages new information required for path design when designing paths (transmission routes) for the optical transmission network N that is compatible with multiple bands. The transmission network management device 30 also performs path design and controls the optical transmission device 90 to perform operations such as adding and dropping optical signals.

[0016] The optical terminal device 80 is a device that is installed between an optical fiber line (optical outlet installed on the wall) installed in a home or the like and a personal computer to connect the optical fiber line and the personal computer and convert between optical signals and digital signals. Examples of such devices include a transponder or APN-T.

[0017] The optical transmission device 90 controls the addition or drop of optical signals by using SDN (Software Defined Network) control or the like.

[0018] [Hardware Configuration] Next, the electrical hardware configuration of the transmission network management device 30 will be described with reference to Fig. 2. Fig. 2 is a diagram showing the electrical hardware configuration of the transmission network management device according to the embodiment.

[0019] As shown in Figure 2, the transmission network management device 30 has a drive device 1000, an auxiliary storage device 1002, a memory device 1003, a processor 1004, an interface device 1005, a display device 1006, an input device 1007, an output device 1008, etc., which are all connected to each other by a bus 1010.

[0020] The program that realizes the processing on the computer is stored on a recording medium 1001, such as a CD-ROM or a memory card, for example. When the recording medium 1001 storing the program is set in the drive device 1000, the program is installed from the recording medium 1001 to the auxiliary storage device 1002 via the drive device 1000. However, the program does not necessarily have to be installed from the recording medium 1001, but may be downloaded from another computer via a communication network such as the Internet. The auxiliary storage device 1002 stores the installed program as well as necessary files, data, etc.

[0021] When an instruction to start a program is received, the memory device 1003 reads the program from the auxiliary storage device 1002 and stores it. The processor 1004 realizes functions related to the device in accordance with the program stored in the memory device 1003. The processor 1004 may include not only a CPU (Central Processing Unit) but also a GPU (Graphics Processing Unit).

[0022] The interface device 1005 is used as an interface for connecting to a communication network, etc. The display device 1006 displays a GUI (Graphical User Interface) etc. according to a program. The input device 1007 is composed of a keyboard, mouse, buttons, a touch panel, etc., and is used to input various operation instructions. The output device 1008 outputs the calculation results to an external device (external display device, printer, etc.).

[0023] [Functional Configuration of Transmission Network Management Device] Next, the functional configuration of the transmission network management device 30 will be described with reference to Fig. 3. Fig. 3 is a diagram showing the functional configuration of the transmission network management device.

[0024] 3, the transmission network management device 30 includes a physical topology information management unit 40, a logical topology information management unit 50, and a path design function unit 70. Each of these units has a function that is realized by instructions from the processor 1004 in FIG. 2 based on a program.

[0025] <Relationship between logical topology and physical topology> First, the relationship between logical topology and physical topology will be explained using Figure 4. Figure 4 is a diagram showing the relationship between logical topology and physical topology. When designing a path, logical calculations (route design and wavelength design) using logical topology information are linked with estimation of actual transmission quality using physical topology information.

[0026] 4, for example, the logical topology information includes link information β1 indicating that an optical fiber of a first wavelength band is to be used between optical transmission devices 90A and 90B at both ends, and link information β2 indicating that an optical fiber of a second wavelength band is to be used. The link information is composed of a list of one or more pieces of section information.

[0027] On the other hand, for example, the physical topology information includes each functional component of the optical transmission devices 90A and 90B that are actually used, fiber path information b1 corresponding to link information β1, and fiber path information b2 corresponding to link information β2.

[0028] 4, the fiber path information b1 includes fiber information a1 and a2, and information about a fiber connection device 100 for connecting optical fibers in the wavelength bands indicated by the fiber information a1 and a2. The fiber connection device 100 is, for example, a patch panel or a fiber cross connect. Here, the fiber connection device 100 is included in the functional components.

[0029] Furthermore, the fiber information a1 includes values ​​(information) of the loss (transmission loss) FL11 of the optical fiber (here, SMF) itself, and the losses (transmission losses) CL11 and CL12 of the connectors involved in connecting this optical fiber to the functional components at both ends. On the other hand, the fiber information 1b includes values ​​(information) of the loss (transmission loss) FL21 of the optical fiber (here, DSF) itself, and the losses (transmission losses) CL21 and CL22 of the connectors involved in connecting this optical fiber to the functional components at both ends.

[0030] On the other hand, the fiber path information b2 includes the loss (transmission loss) FL12 of the optical fiber (here, SMF) itself, and the values ​​(information) of the losses (transmission losses) CL13 and CL14 of the connectors associated with connecting this optical fiber to the functional components at both ends.

[0031] In this way, even when multiple types of optical fiber (SMF, DSF) with different available wavelength bands are connected via the fiber connection device 100, by using the fiber path information b1 containing the fiber information a1 and a2, it is possible to design paths for an optical transmission network that supports multiple bands.

[0032] Next, the contents of the physical topology information and logical topology information will be described in detail below.

[0033] <Physical Topology Information Management Unit> The physical topology information management unit 40 stores and manages each piece of information in the fiber information management unit 41, fiber path information management unit 42, functional component information management unit 43, and functional component connection information management unit 44, and reads each piece of information from the fiber information management unit 41, fiber path information management unit 42, functional component information management unit 43, and functional component connection information management unit 44. The fiber information management unit 41, fiber path information management unit 42, functional component information management unit 43, and functional component connection information management unit 44 are databases or the like constructed in the auxiliary storage device 1002 or the memory device 1003. The following ID is an example of identification information.

[0034] (Fiber Information Management Unit) Fig. 5A is a diagram showing fiber information managed by the fiber information management unit. The fiber information is acquired from an external design system or the like.

[0035] The fiber information includes the optical fiber ID, information about the functional components at both ends of the optical fiber, and information about the optical fiber, which are associated with each other. The functional components are, for example, an amplifier (AMP), a wavelength selective switch (ROADM), or a fiber connector (FXC), as shown in Figure 4, and are components that affect transmission quality loss, etc.

[0036] The information about functional components includes the name of the functional component and information indicating the connector loss (transmission loss) associated with the connection to the optical fiber. The information about optical fibers includes information indicating the type of optical fiber, the optical fiber transmission distance, and the optical fiber loss (transmission loss).

[0037] The information about the optical fiber may include information indicating characteristic values ​​such as chromatic dispersion. Furthermore, since each loss and characteristic value is often measured between optical transmission devices 90, the loss and characteristic value for each optical fiber section are displayed as the measured values ​​between the optical transmission devices 90 divided by the distance.

[0038] (Fiber Path Information Management Unit) Fig. 5B is a diagram showing fiber path information managed by the fiber path information management unit. The fiber path information is updated by the fiber connection device 100 when a change is made to the fiber connection.

[0039] The fiber path information is connection information of optical fibers between optical transmission devices 90, and indicates information regarding the splicing of optical fibers between functional components. As shown in Fig. 5B, the fiber path information includes, in association with each other, a fiber path ID, names of functional components at both ends of the optical fiber, information about the optical fiber, and the total loss between the optical fiber and the functional components at both ends of the optical fiber.

[0040] Furthermore, the information about the optical fiber in the fiber path information includes the ID of the optical fiber to be used (see Figure 5A), the total transmission distance of the optical fiber, and information indicating the wavelength band of the available light. Note that "L" indicates that it can only be used in the L band, and "C+L" indicates that it can be used in both the C band and the L band. In this case, the optical fiber ID "#F1" is an SMF type and therefore can be used in both the C band and the L band, but the optical fiber ID "#F2" is a DSF type and therefore can only be used in the L band. Therefore, if both the optical fibers with the optical fiber ID "#F1" and the optical fiber ID "#F2" are spliced ​​together, only the L band, which is common to both optical fibers, can be used.

[0041] (Functional Component Information Management Unit) Fig. 5C is a diagram showing functional component information managed by the functional component information management unit 100. The functional component information is acquired from an external design system or the like.

[0042] As shown in FIG. 5C, the functional component information includes information on the ID of the functional component, the name of the functional component, the type of the functional component, and the transmission characteristics of the functional component, all of which are associated with each other.

[0043] (Functional Component Connection Information Management Unit) Fig. 5D is a diagram showing functional component connection information managed by the functional component connection information management unit 100. The functional component connection information indicates the connection relationships between functional components.

[0044] As shown in FIG. 5D, the functional component connection information includes the ID of the functional component connection information and the IDs of the functional components at both ends of the optical fiber, which are associated with each other.

[0045] <Logical Topology Information Management Unit> The logical topology information management unit 50 stores and manages each piece of information in the section information management unit 51, the link information management unit 52, and the optical transmission device information management unit 53, and reads each piece of information from the section information management unit 51, the link information management unit 52, and the optical transmission device information management unit 53. The section information management unit 51, the link information management unit 52, and the optical transmission device information management unit 53 are databases or the like constructed in the auxiliary storage device 1002 or the memory device 1003.

[0046] The logical topology information management unit 50 also includes a section information derivation unit 61, a link information derivation unit 62, and an optical transmission device information derivation unit 63. Each of these units has a function that is realized by an instruction from the processor 1004 in FIG. 2 based on a program.

[0047] (Section Information Management Unit) The section information management unit 51 manages section information. The section information is derived by the section information derivation unit 61, and the information managed by the section information management unit 51 is updated. The section information is information used when creating link information, and its content is similar to the fiber path information described below, so the section information management unit 51 may be omitted. Accordingly, the section information derivation unit 61 may also be omitted.

[0048] (Link Information Management Unit) The link information management unit 52 manages link information as shown in Fig. 6A. The link information is derived by the link information derivation unit 62, and the information managed by the link information management unit 52 is updated.

[0049] 6A, the link information includes, in association with each other, information on the link information ID, the IDs of the optical transmission devices at both ends, the IDs of each fiber path (transmission path by optical fiber), the cost value of each optical fiber, the wavelength band of available light for each optical fiber, the total transmission distance which is the sum of the transmission distances of each optical fiber, and the total loss (similar to FIG. 5B). For example, in the case of optical transmission devices 90A and 90B at both ends, when the fiber path is "#P1", the cost value is "x" and the available wavelength of light is "L band".

[0050] Here, the "cost value" of the link information is a value used when selecting a band (optical fiber) in route design, and is a value that indicates the ease (or difficulty) of selection from multiple types of optical fiber (bands) with different wavelength bands when designing a route. For example, if the transmission distance of each optical fiber is used as the cost value, if a shorter transmission distance is preferable, the cost value is lowered so that the band (optical fiber) is more likely to be selected when designing a route, and if the transmission distance is long, it is less likely to be selected as it is considered high cost. The cost value is set by a maintenance person, etc.

[0051] (Optical Transmission Device Information Management Unit) The optical transmission device information management unit 53 manages optical transmission device information as shown in Fig. 6B. The optical transmission device information is derived by the optical transmission device information derivation unit 63, and the information managed by the optical transmission device information management unit 53 is updated.

[0052] As shown in FIG. 6B, the optical transmission device information management unit 53 manages the ID of the optical transmission device and information indicating the functional components that configure the path (transmission route) in association with each other.

[0053] (Section Information Derivation Unit) The section information derivation unit 61 acquires the fiber information managed by the fiber information management unit 41 and the fiber path information managed by the fiber path information management unit 42, and derives section information based on the fiber information and the fiber path information. Note that the section information derivation unit 61 derives the section information when a path is designed, but it may also be possible to derive and manage the section information before the path is designed, thereby enabling rapid path design.

[0054] (Link information derivation unit) The link information derivation unit 62 derives link information from the section information managed by the section information management unit 51, or directly from the fiber information managed by the fiber information management unit 41 and the fiber path information managed by the fiber path information management unit 42.

[0055] (Optical transmission device information derivation unit) The optical transmission device information derivation unit 63 derives optical transmission device information based on the functional component information managed by the functional component information management unit 43 and the functional component connection information managed by the functional component connection information management unit 44.

[0056] <Path Design Function Unit> The path design function unit 70 has a graph data derivation unit 71, a route design / wavelength design unit 72, and a transmission quality estimation unit 73. Each of these units is a function realized by an instruction from the processor 1004 in FIG. 2 based on a program.

[0057] (Graph Data Derivation Unit) The graph data derivation unit 71 derives logical topology information (graph data) using link information and optical transmission device information acquired from the logical topology information management unit 50. Note that the logical topology information management unit 50 may include the graph data derivation unit 71.

[0058] (Route Design / Wavelength Design Unit) The route design / wavelength design unit 72 uses, for example, Dijkstra's algorithm (Reference 1) or k-shortest path routing (Reference 2) to search for a route based on cost values ​​in the logical topology information, and finds multiple route candidates. (Reference 1) Dijkstra's algorithm<https: / / ja.wikipedia.org / wiki / %E3%83%80%E3%82%A4%E3%82%AF%E3%82%B9%E3%83%88%E3%83%A9%E6%B3%95#> (Reference 2) k shortest path routing<https: / / en.wikipedia.org / wiki / K_shortest_path_routing > The route design and wavelength design unit 72 also preferentially selects a band (wavelength band) with a large amount of available space, or selects a band depending on the distance between the path endpoints. Furthermore, the route design and wavelength design unit 72 assigns a predetermined band from the selected bands to each route candidate, and derives the predetermined route candidate for which the assignment was successful as a path candidate.

[0059] (Transmission Quality Estimation Unit) The transmission quality estimation unit 73 acquires fiber path information and functional component connection information managed by the physical topology information management unit 40, and calculates and estimates the transmission quality for each path candidate based on the fiber path information and the functional component connection information. The route design / wavelength design unit 72 completes the path design by selecting one route based on the transmission quality for each path candidate estimated by the transmission quality estimation unit 73 and the cost value in the logical topology information.

[0060] [Processing of the embodiment] Next, the processing executed by the transmission network management device 30 will be described with reference to FIGS.

[0061] <Preliminary Management Processing> First, a process for managing new information required for path design when designing a path (transmission route) in an optical transmission network that supports multiband will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the process for managing new information required for path design.

[0062] S11: When a maintenance person or the like updates the fiber connection using the fiber connection device 100, the physical topology information management unit 40 updates the fiber path information in the fiber path information management unit 42.

[0063] S12: The section information derivation unit 61 derives the section information based on the fiber information and fiber path information, and stores and manages the section information in the section information management unit 51.

[0064] S13: The link information derivation section 62 derives link information based on the section information, and stores and manages the link information in the link information management section 52.

[0065] S14: The optical transmission device information deriving unit 63 derives optical transmission device information based on the functional component information and the functional component connection information, and stores and manages the optical transmission device information in the optical transmission device information management unit 53.

[0066] <Path Design Processing> Next, the path design processing will be described with reference to Fig. 8. Fig. 8 is a flowchart showing the path design processing.

[0067] S21: When the path design function unit 70 receives a path design request through operation by a maintenance person or the like, the graph data derivation unit 71 derives graph data based on the link information and optical transmission device information managed by the logical topology information management unit 50.

[0068] S22: The route design and wavelength design unit 72 derives predetermined route candidates that have been successfully allocated through route search, band (optical fiber) selection, and band (optical fiber) allocation as path candidates.

[0069] S23: The transmission quality estimation unit 73 calculates and estimates the transmission quality for each path candidate based on the fiber path information and functional component connection information managed by the physical topology information management unit 40.

[0070] S24: The route design and wavelength design unit 72 selects one route, thereby completing the path design.

[0071] [Major Effects of the Embodiment] As described above, in the present embodiment, even in an environment where multiple types of optical fibers with different wavelength bands are mixed, when designing paths for an optical transmission network that supports multiple bands (multiple wavelength bands), by managing new information required for path design, it is possible to achieve an increase in capacity and economy of the transmission network.

[0072] [Supplementary Note] The present invention is not limited to the above-described embodiment, and may have the following configurations or processes (operations), for example.

[0073] (1) The transmission network management device 30 can be realized by a computer and a program, but this program can also be recorded on a (non-temporary) recording medium and provided, or the program can be provided via a communication network such as the Internet.

[0074] (2) The processor 1004, which is hardware, may be a single processor or multiple processors.

[0075] 10 Communication system 30 Transmission network management device 40 Physical topology information management unit 41 Fiber information management unit 42 Fiber path information management unit 43 Functional component information management unit 44 Functional component connection information management unit 50 Logical topology information management unit 51 Section information management unit 52 Link information management unit 53 Optical transmission device information management unit 61 Section information derivation unit 62 Link information derivation unit 63 Optical transmission device information derivation unit 70 Path design function unit 71 Graph data derivation unit 72 Route design / wavelength design unit 73 Transmission quality estimation unit 80a, 80b Optical terminal device 90a, 90b, 90c, 90d Optical transmission device

Claims

1. A transmission network management device that manages information necessary for path design when designing paths in a transmission network that can support multiple bands, comprising: a physical topology information management unit that manages physical topology information used to estimate transmission quality in the path design; and a logical topology information management unit that manages logical topology information used in route design and wavelength design in the path design, the logical topology information including cost values ​​that indicate the ease or difficulty of selection from multiple types of optical fiber in different wavelength bands when designing the route.

2. The transmission network management device of claim 1, wherein the physical topology information includes fiber information including information about functional components that are both ends of the optical fiber and information about the optical fiber, and fiber path information that is connection information about the optical fibers between multiple optical transmission devices and indicates information about the splicing of the optical fibers between multiple functional components.

3. The transmission network management device according to claim 2, wherein the fiber information includes information on the type of optical fiber, the transmission distance of the optical fiber, and the transmission loss of the optical fiber, and the fiber path information includes the optical fiber to be used, the total transmission distance of the optical fiber to be used, the wavelength band of available light, and the total transmission loss between the functional components at both end points and the optical fiber.

4. A transmission network management device as described in claim 1, wherein the physical topology information includes functional component information including the names of functional components that are both end points of the optical fiber, the type of the functional component, and information on the transmission characteristics of the functional component, and functional component connection information including information identifying the functional components that are both end points of the optical fiber.

5. The transmission network management device of claim 1, wherein the logical topology information includes the cost value and, in the case where multiple types of optical fiber are used, includes link information including information indicating the available optical wavelength band, the total transmission distance of each optical fiber, and the total transmission loss, as well as transmission device information indicating the functional components that make up the path for each optical transmission device.

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