JP5488206B2 - Optical fiber line design support device and program - Google Patents

Description

  The present invention relates to an optical fiber line design support apparatus and program for supporting the design of an appropriate optical fiber line connecting a start point and an end point based on information of an already installed optical fiber network.

  A large amount of optical fiber cables are laid in urban areas, and each optical fiber cable is formed by bundling several to several thousand optical fiber cores. Nodes called closures are installed at locations where a plurality of optical fiber cables are connected, and optical fiber cores corresponding to each other of different optical fiber cables are connected within the closure. These existing optical fiber networks composed of optical fiber cables and closures are managed by an optical fiber network database that records the network configuration and the operational classification (in operation or non-operation) of each core wire.

  When designing an optical fiber line that connects two desired points (starting point and end point), refer to the optical fiber network database and use only the optical fiber core line whose operation category is not in operation, and use the route. It is necessary to specify the core number and the location of the closure that requires the core connection replacement work. Up to now, such optical fiber line design work has been performed manually by skilled engineers. However, manual line design by skilled engineers requires an optimal solution for the line length or above a certain level. It is not possible to confirm whether a favorable solution has been obtained.

  A Dijkstra method described in Non-Patent Document 1 is known as a method for searching for the shortest path connecting two points, and is widely used in, for example, car navigation systems.

E. W. Dijkstra, "A note on two problems in connection with graphs," Numerische Mathematik, Vol. 1, pp. 269-271, (1959).

  Since several to thousands of optical fiber cores are bundled in each optical fiber cable constituting the optical fiber network, the number of combinations of the core connection in the closure is very large. The number of combinations further increases when taking into account the combination of cutting the already connected core wires and reconnecting them to other core wires in the closure. Therefore, simply applying the shortest path search method described in Non-Patent Document 1 to the determination of an optical fiber line in an optical fiber network results in an enormous number of path candidates or combinations to be calculated. Takes a lot of time.

  For example, when two optical fiber cables composed of 1,000 cores are drawn into the same closure and none of the cores are connected, the method described in Patent Document 1 is used. In consideration of connection switching, 1,000,000 (= 1,000 × 1,000) virtual connection candidates must be calculated. When the number of closures interposed between the starting point and the ending point increases, the number of combinations increases exponentially, and enormous calculation is required even by a computer.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical fiber line design support apparatus and program for supporting the design of an appropriate optical fiber line that connects a starting point and an end point in an existing optical fiber network.

  An optical fiber line design support apparatus according to the present invention reaches from an origin to an end in a laid optical fiber network comprising a plurality of optical cables each accommodating a plurality of optical fiber cores and a plurality of closures connecting the optical cables. An optical fiber line design support apparatus for supporting the design of an optical fiber line, comprising: a means for designating the start point and the end point; and an optical fiber core wire that is not in operation from the optical fiber core wires constituting the optical fiber network. After extracting, the path setting unit for the isolated optical fiber core and the connected optical fiber core as a unit, and the path into a path group in which both ends and intermediate closures and intermediate optical cables are the same. Means for classifying, route search means for searching for a route from the starting point to the end point in units of the path group, and the route search In path group constituting the searched route in stages, characterized by comprising a means for determining a small optical fibers of connection construction load in closure the path group passes in the closure section.

An optical fiber line design support program according to the present invention reaches from an origin to an end in an installed optical fiber network comprising a plurality of optical cables each housing a plurality of optical fiber cores and a plurality of closures connecting the optical cables. an optical fiber line design support program for supporting a design of optical fiber lines, after extracting the optical fiber in a non-operational from an optical fiber constituting an equivalent optical fiber network, isolated optical fiber center a function to set the path for the line and a connected optical fiber units, and the functions those said path, you fall into both ends and the middle of the closure as well as the path group middle of the optical cable are the same, those wherein a unit of path group construction and route search function to search for a route from the starting point to the said end point, the route searched in this pathway searching function In the path group that is intended for realizing a function and that determine fewer optical fibers of connection construction load in closure the path group passes in the closure section on the computer.

  According to the present invention, an optical fiber line can be determined in a short time even in an optical fiber network including an enormous number of optical fiber cores.

It is a schematic block diagram of one Example of this invention. An example of information during operation of the optical fiber core wire is shown. An example of optical fiber core wire connection information is shown. An example of the cable length of an optical cable is shown. The flowchart of an optical fiber line design support program is shown. The structural example of the optical fiber network for description is shown. 7 shows an optical fiber core information table corresponding to the optical fiber network example shown in FIG. 7 shows a core connection information table corresponding to the optical fiber network example shown in FIG. 7 shows a cable information table corresponding to the optical fiber network example shown in FIG. The structure which excluded the optical fiber core wire in operation from the optical fiber network example shown in FIG. 6 is shown. The path group set with respect to the optical fiber network example shown in FIG. 6 is shown. An example of the structure and contents of a path information table corresponding to the path group shown in FIG. 11 is shown. FIG. 7 shows an optical network configuration when the optical fiber network example shown in FIG. 6 is viewed in units of path groups. FIG. The network block diagram of the state which set the virtual node to each closure is shown. The route obtained by applying the route search by the Dijkstra method to the configuration shown in FIG. The optical fiber core wire to be used finally and the determined core wire connection construction location are shown. It is an explanatory example of the shortest path search algorithm by the Dijkstra method.

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

  FIG. 1 shows a schematic block diagram of an embodiment of the present invention. The optical fiber line design support apparatus according to the present invention is realized by installing and operating an optical fiber line design support program in a computer.

  An input device 12 such as a keyboard and a display device 14 are connected to the CPU 10 of the computer. On the CPU 10, the optical fiber line design support program of this embodiment operates. The parameter storage device 16 stores various parameters necessary for the optical fiber line design support program on the CPU 10. The parameter storage device 16 includes, for example, a RAM constituting the computer or a hard disk device as a secondary storage device.

The optical fiber network database (DB) 18 is stored on a hard disk or a server connected via a network. The optical fiber network DB 18 includes closure information of each closure constituting an optical fiber network laid in various places, and optical cable information of each optical cable. Specifically, the closure is C _i and the optical cable is E _j . The k-th optical fiber core accommodated in the optical cable E _j is denoted as F _{j, k} . However, i = 1 to K1, j = 1 to K2, and k = 1 to K3. There are K1 closures, K2 optical cables, and K3 (j) optical fiber cores accommodated in each optical cable E _j in an area to be selected. K3 (j) is generally different for each optical cable, depends on the optical cable _{E j.}

In the optical fiber network DB 18, the closure information of the closure C _i includes the closure identification number (ID), the position coordinates P _i (x _i , y _i ), and the pair of optical fiber core wires connected within the closure C _i { It consists of cord connection information indicating (F _{i1, j1} , F _{i2, j2} )}. The optical cable information of the optical cable E _j indicates an optical cable identification number (ID), a cable length, the number of optical fiber cores K3 to be accommodated, and whether each of the optical fiber cores F _{j, k} to be accommodated is in operation. It consists of an in-operation flag, that is, information on in-core operation, and end point information (Ca, Cb) indicating closure at both end points. FIG. 2 shows an example of in-operation information of the optical fiber cores _{Fj, k} , and FIG. 3 shows an example of optical fiber core connection information. FIG. 4 shows an example of the cable length of the optical cable.

  The operator uses the input device 12 to input a closure that is a starting point and an ending point of the optical fiber line to be designed. The display device 14 displays the result obtained by the optical fiber line design support program operating on the CPU, and also displays the progress in the middle if necessary.

  The optical fiber line design support program includes a preprocessing function 20, a route search function 22, and a design result output function 24 as main functions executed by the CPU 10. The preprocessing function 20 converts the network stored in the optical fiber network DB 18 into a graph G (N, E) suitable for route search, and stores the parameters at the time of conversion in the parameter storage device 16. The route search function 22 calculates an optimal route connecting the starting point and the ending point or a preferable route more than a certain value in the graph G (N, E) obtained by the preprocessing function 20. As a route calculation method, there is a Dijkstra method described in Non-Patent Document 1. The design result output function 24 generates graphic information indicating the optical fiber line connecting the start point and the end point based on the shortest path obtained by the path search function 22 and the parameter stored in the parameter storage device 16. It is displayed on the screen of the display device 14.

FIG. 5 shows a flowchart of the optical fiber line design support program. It is assumed that the starting point and the ending point have already been input by the input device 12. FIG. 6 shows a configuration example of an optical fiber network for explanation. The optical fiber network shown in FIG. 6 includes six closures C _{1 to} C ₆ and seven optical fiber cables E _{1 to} E ₇ , and each of the optical fiber cables E _{1 to} E ₇ has four optical fiber cores. Including. In FIG. 6, the broken line indicates the optical fiber core wire in operation, and the solid line indicates the optical fiber core wire in non-operation state. The numerical value attached to the optical fiber core wire indicates the core wire number. L ₁ ~L ₇ shows the cable length of the optical fiber cable _E 1 to E ₇ a (miles). Closures C ₁ is designated as the starting point, the closure C ₆ is specified as the end point. 7, FIG. 8, and FIG. 9 show an optical fiber core information table, a core connection information table, and a cable information table corresponding to the optical fiber network shown in FIG.

The preprocessing function 20 extracts non-operating optical fiber core wires {F _{j, k} } of all optical fiber cables {E _j } registered in the optical fiber network DB 18 and outputs non-operating light. A temporary database having the same structure as the optical fiber network DB 18 including only the fiber cores is generated (S1). Extraction of a non-operating optical fiber core can be easily realized by referring to the in-core information during operation of the optical cable information. FIG. 10 shows a configuration in which an optical fiber core wire in operation is excluded from the optical fiber network shown in FIG.

  The pre-processing function 20 further refers to the optical fiber core connection information, generates a path indicating the serial connection state of the non-operational optical fiber from the non-operational optical fiber extracted in step S1, A path information table describing the path information is generated (S2).

  Specifically, the extracted optical fiber core wires in step S1 are collected into connected ones. That is, the optical fiber cores connected to each other by the closure are evaluated as a single path. Of course, an isolated optical fiber core that is disconnected at both ends, that is, open, is a single path by itself. For each such path, a path information table is generated that includes information indicating the closures located at both ends and the optical fiber cores that constitute the paths. Paths whose both ends are located in the same closure and whose intermediate optical fiber cores belong to the same optical fiber cable belong to the same group, and the path group number by this grouping is described in the path information table.

FIG. 11 shows the path groups P _{1 to} P ₆ after grouping the paths set in step S2 with respect to the optical fiber network shown in FIG. For example, the path group _{P 2} from the closure _{C 1,} cable _{E 1,} the closure _{C 2,} cable _{E 4,} the closure _{C 5,} cable _{E 6,} via the closure _{C 4} and the cable _{E 3,} reaches the closure _{C 1} It consists of two passes. FIG. 12 shows the structure and example contents of the path information table corresponding to the path group shown in FIG.

  As shown in FIG. 12, the path information table generated in step S2 includes a number that identifies each path (for example, a serial number), a number that identifies a path group (path group number), and closures at both ends (start and end points). ), A closure on the path and path closure / cable information indicating an optical cable, and core number information indicating one or a plurality of optical fiber cores constituting the path. For the process described later, information indicating the total length of the path is also included for each path. Paths having the same end closure number and route closure / cable information but different core number information belong to the same path group.

  The preprocessing function 20 stores the path information table generated in step S2 in the parameter storage device 16 (S3).

  The route search function 22 refers to the path information table stored in the parameter storage device 16 and searches for a desirable route connecting the start point and end point specified by the operator (S4). The search condition is that the cable length is the shortest.

  As the search condition, the number of closures via or the number of connections in the closure may be considered simultaneously. For example, the number of closures that pass through can be searched for the optimum route under the distance condition by replacing one closure with an appropriate distance. Of course, an appropriate route may be determined by adding the number of via closures to a plurality of candidates under the distance condition. Furthermore, in addition to the distance condition, it may be added to the search condition that the number of closed closures is small.

  The operation of the route search based on the distance condition executed by the route search function 22 will be specifically described. Here, the Dijkstra method described in Non-Patent Document 1 is applied.

As shown in FIG. 13, in each of the closures C _{1 to} C ₆ , connection end points and open end points of paths, that is, end points of optical fiber core wires, are evaluated as nodes. Next, as shown in FIG. 14, one virtual node is assumed for each closure, and a virtual path that connects the virtual node and a node in the same closure on a one-to-one basis is assumed. The virtual path is given a track length that reflects the cost of changing the core connection. An optical fiber cable connecting between the closures and a virtual path in the closure is defined as an edge E, and a graph G (N, E) is formed together with a node N including a virtual node, and an optimal route is searched by the Dijkstra method. Here, each edge is weighted in units of line length.

  FIG. 15 shows routes obtained by applying route search by the Dijkstra method to the configuration shown in FIG. A solid line indicates a route obtained by the route search, and a broken line indicates a route candidate as a premise of the route search.

  The CPU 10 refers to the path information table stored in the parameter storage device 16 with respect to the route determined by the route search function 22 (FIG. 15), and selects the optical fiber core wire that reduces the load of connection work in the closure through which it passes. It is determined in each closure section (S5). If the route determined in step S4 for a closure other than the start point and the end point passes through a virtual node, since the core wire connection work occurs in the closure, it is marked as a core wire connection work point. FIG. 16 shows the optical fiber core wire to be finally used and the determined core wire connection construction location.

  The shortest path search algorithm by Dijkstra method will be briefly described. FIG. 17 shows an optical fiber network in which a path is a straight line (edge) and a closure is a white square (node). The distance between connection points of each path is assumed to be known. When the starting and ending nodes are specified under such initial conditions, the shortest path connecting both points is obtained by the Dijkstra method as follows.

  In the Dijkstra method, first, a primary node A1 to A2 that is adjacent to the 0th order node along the edge is searched from the 0th order node as a starting point, and for each primary node A1 to A2, a corresponding one previous node ( The total distance from the departure point via the first order node, which is the origin node itself). Then, in the node list of each of the primary nodes A1 to A2, the node number for specifying the immediately preceding node, the cumulative distance, and the search order 1 are registered.

  Next, for each of the nodes A1 to A2, the secondary node Bij is searched, and for each secondary node, the cumulative distance from the departure place via the corresponding primary node is obtained, and the secondary node Bij In the node list, a node number that identifies the previous node, a cumulative distance, and a search order 2 are registered.

  For example, three secondary nodes B11, B12, and B13 are found for the primary intersection A1. For the node B11, the node number indicating the upper node A1, the cumulative distance Bd11, and the search order 2 are stored. For the node B12, the node number indicating the upper node A1, the cumulative distance Bd12, and the search order 2 are stored. For the node B13, the node number indicating the upper node A1, the cumulative distance Bd13, and the search order 2 are stored.

  A similar process is executed for the primary node A2. Two secondary nodes B21 and B22 are obtained for the primary node A2. For the node B21, the node number indicating the upper node A1, the cumulative distance Bd21, and the search order 2 are stored. For the node B22, the node number indicating the upper node A1, the cumulative distance Bd22, and the search order 2 are stored.

  For all primary nodes, search for adjacent secondary nodes, and after storing the above information, search for secondary node duplication. In the example illustrated in FIG. 17, the node B13 and the node B21 are the same node. When cumulative distances on different routes are stored for the same node, the cumulative distances Bd13 and Bd21 are compared, the larger route data is discarded, and only the smaller route data is stored. For example, when Bd13> Bd21, the cumulative distance Bd21 and the corresponding number of the previous node A2 are finally stored in the node B13 (= B21).

  Thereafter, similarly, an adjacent tertiary node Cij is obtained for each secondary node Bij, and a cumulative distance from the starting point via the corresponding previous node is obtained for each node Cij, and the previous node number is obtained. Remember with. When there is an overlap in the tertiary node, the cumulative distances from the departure point are compared, the larger upper node number is discarded, and the smaller upper node number is stored.

  By repeating such processing and finally reaching the end point, the route connecting the start point to the end point is found by tracing back the list of nodes stored so far.

  The design result output function 24 of the CPU 10 outputs the route calculated by the route search function 22 to the display device together with the optical fiber core wire constituting the route and the closure requiring the core wire connection work.

  In this way, a path consisting of non-operating optical fiber cores is extracted in units of connected optical fiber cores, paths that make up the same path are grouped, and a path is searched for in each path group unit Therefore, the number of combinations of routes to be searched can be reduced. Thereby, the processing time of the route search can be greatly shortened.

  At the path group stage, the number of combinations of paths to be searched is reduced, so that it is possible to obtain a result in a practical time not by the Dijkstra method but by the brute force method. For example, it is possible to design a desirable route by listing all possible routes connecting the starting point and the ending point, sorting according to the number of core wire connection construction locations and / or line lengths, and extracting higher candidates.

  According to the present embodiment, a preferable optical fiber line having a short line length or a small number of places for replacing the core wire is provided for the optical fiber network including the optical fiber cables that accommodate a large number of optical fiber cores. Design in a short time. Even when considering the replacement of optical fiber core wires in the closure, the number of combinations of paths to be searched is reduced by preprocessing, so that the amount of calculation required for line design can be greatly reduced.

  Although the invention has been described with reference to specific illustrative embodiments, various modifications and alterations may be made to the above-described embodiments without departing from the scope of the invention as defined in the claims. This is obvious to an engineer in the field to which the present invention belongs, and such changes and modifications are also included in the technical scope of the present invention.

10: CPU
12: input device 14: display device 16: parameter storage device 18: optical fiber network database (DB)
20: Pre-processing function 22: Route search function 24: Design result output function

Claims (2)

An optical fiber line design that supports the design of the optical fiber line from the start point to the end point in an installed optical fiber network consisting of a plurality of optical cables each accommodating a plurality of optical fiber cores and a plurality of closures connecting the optical cables. A support device,
Means for designating the start point and the end point;
Means for extracting a non-operating optical fiber core from an optical fiber core constituting the optical fiber network, and setting a path in units of the isolated optical fiber core and the connected optical fiber core; ,
Means for classifying the paths into path groups in which both ends and intermediate closures and intermediate optical cables are the same;
Route search means for searching for a route from the starting point to the end point in units of the path group;
Means for determining, in a closure section, an optical fiber core wire having a low connection work load in a closure through which the path group passes in a path group constituting a route searched by the route search means. Fiber line design support device. An optical fiber line design that supports the design of the optical fiber line from the start point to the end point in an installed optical fiber network consisting of a plurality of optical cables each accommodating a plurality of optical fiber cores and a plurality of closures connecting the optical cables. A support program,
On extracting the optical fiber in a non-operational from an optical fiber constituting an equivalent optical fiber network, to set the path for the isolated optical fiber and a connected optical fiber units Function and
The person said path, and ability to classify both ends and the middle of the closure as well as the path group middle of the optical cable are the same,
In units of those said path group, a route search function to search for a route from the starting point to the said end point,
In path group constituting the searched route in this pathway searching function, for realizing the function and that determine fewer optical fibers of connection construction load in closure the path group passes in the closure section on a computer Optical fiber line design support program.

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