JP4024266B2 - Optical path arrangement search method, optical path arrangement search apparatus and program - Google Patents

Description

  The present invention relates to an optical path arrangement search device, an optical path arrangement search method, and a program used in an optical communication network using wavelength division multiplexing.

  In recent years, communication demand has been rapidly increasing due to the spread of the Internet and the like. Correspondingly, a high-speed and large-capacity optical communication network using an optical fiber or the like is being developed. As a technique used in such an optical communication network, wavelength division multiplexing (WDM) is drawing attention. WDM is a technique for multiplexing carrier waves having different optical wavelengths. By using WDM, a plurality of carrier waves can be propagated in parallel on one optical transmission line. For this reason, a large-capacity optical communication network can be constructed at low cost.

  An optical communication network using WDM includes a plurality of node devices each provided with a router, and an optical transmission path that is configured by optical fibers and connects the node devices. In this optical communication network, devices having an optical add / drop function (OADM), an optical cross connect function (OXC), and the like are used as each node device. OADM is a function that inserts a carrier wave of another wavelength into a carrier wave that is wavelength-multiplexed using WDM, and branches a carrier wave of a specific wavelength from the wavelength-multiplexed carrier wave. OXC is a function for switching a propagation path of a carrier wave multiplexed using WDM on a wavelength basis. By using these functions, it is possible to construct an optical path arrangement composed of a plurality of optical paths on an optical communication network constructed by optical transmission paths.

  When a situation that hinders communication such as failure or congestion occurs in an optical communication network using WDM, by dynamically changing the optical path arrangement, an optical path in which a situation that hinders communication occurs is avoided, Thus, a method for restoring the communication state has been proposed. The optical path arrangement can be changed by bypassing a failure or congestion section (hereinafter simply referred to as a failure section) or by cutting through a node device in which congestion has occurred. Here, the cut-through means that an optical signal is passed as it is without using the routing function of the node device, that is, using only OADM or OXC (for example, refer to Patent Document 1). By setting a cut-through path for a node device in which congestion has occurred, the processing load on the node device can be reduced.

A dedicated protection method and a shared protection method are known as methods for dynamically changing an optical path to bypass a faulty section. The dedicated protection method is a method of substituting one optical path with another optical path. The shared protection method is a method of substituting a plurality of optical paths with another single optical path.
Japanese Patent Application Laid-Open No. 2002-354921

  Here, in the conventional dedicated protection method and the shared protection method described above, when traffic is concentrated on a specific node device, a new optical path that cuts through the node device is newly set. Processing load can be reduced. However, these conventional methods are merely methods for recovering the communication state by bypassing the faulty section, and the optical path arrangement after detouring is not necessarily the optimal optical path arrangement. This is because the setting of the optical path that cuts through the node device as described above may increase the processing load of other node devices.

  Also, according to these conventional methods, when the setting of the optical path is changed, the routing information of the IP (Internet protocol) layer is also changed in the optical communication network. Therefore, when a new cut-through path is set, it is determined that the cut-through path is the optimum route, and traffic may concentrate on the cut-through path. In such a case, the processing load on the cut-through node device does not become excessive, but the processing load increases at the node device that terminates the cut-through path.

  For this reason, when a new cut-through path is set, it is desired that traffic concentration does not occur in the entire optical communication network in consideration of a route change in the IP layer.

  However, the number of setting patterns of the optical path arrangement in the entire optical communication network increases exponentially as the number of wavelengths and the number of node devices used in the optical communication network increase. For this reason, if it is attempted to select an optimal cut-through path by predicting the traffic generation situation in the entire optical communication network for all setting patterns, the processing load becomes enormous, which is extremely inefficient and unrealistic.

  In order to solve this problem, the inventors have conducted intensive research and found that the optical path arrangement is maintained while maintaining the logical topology that is the ideal optical path arrangement obtained from the set realistic optical path arrangement. It was found that a more preferable optical path arrangement can be efficiently obtained without performing a search for all the optical path arrangements.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an optical path arrangement search method, an optical path arrangement search apparatus, and a program capable of efficiently obtaining an optical path arrangement. There is.

  In order to achieve the above-mentioned object, an optical path arrangement search method using a genetic algorithm according to the present invention includes a plurality of node devices and an optical fiber for transmitting wavelength multiplexed signals by connecting adjacent node devices. In the optical communication network including the above, the present invention is implemented in searching for a realistic optical path arrangement more suitable than the working optical path arrangement for traffic relayed by each of a plurality of node devices, and includes the following steps.

  First, in the logical topology acquisition process, the logical topology acquisition means includes a node device that branches a plurality of optical paths and terminates the plurality of optical paths with respect to a set working optical path arrangement including a plurality of optical paths. By using the nodes, a logical topology is obtained which is composed of branches and nodes from the working optical path arrangement and gives an ideal optical path arrangement. Next, in the initial code group generation process, the initial code group generation means generates an initial code group including a plurality of gene codes including the node number given to each node device as an element. Next, in the best code selection process, the best code selection means evaluates each of the plurality of gene codes belonging to the initial code group in association with the logical topology, and sets the realistic light path arrangement most. The best genetic code is selected as the best code. Next, in the probabilistic code selection process, the probabilistic code selection means has a selection probability that increases the probability that a superior gene code is selected from the initial code group excluding the best code as a result of the evaluation. Select the number of gene codes. Next, in the code crossover process, the code crossover means prepares a plurality of gene code pairs belonging to the probability selection code group and crosses the gene code for each pair to obtain a crosscode group. Next, in the mutation process, the mutation means causes a mutation in a part of the gene code belonging to the cross code group. Next, in the next generation code group generation process, the next generation code group generation means selects one gene code that has not caused mutation from the cross code group, and selects the selected gene code as the best code. replace. Thereafter, the best code selection process is performed using the cross code group as the initial code group.

  According to another preferred embodiment of the optimum optical path arrangement searching method of the present invention, the following steps are provided.

  First, in the logical topology acquisition process, the logical topology acquisition means includes a node device that branches a plurality of optical paths and terminates the plurality of optical paths with respect to a set working optical path arrangement including a plurality of optical paths. By using the nodes, a logical topology is obtained which is composed of branches and nodes from the working optical path arrangement and gives an ideal optical path arrangement. Next, in the random code generation process, the random code generation means generates a random code including the node number given to each node device as an element. Next, in the best code selection process, the best code selection means evaluates the random code in association with the logical topology, and selects the random code as the best code when it is superior to the working path arrangement.

  In order to achieve the above-described object, an optical communication network comprising a plurality of node devices and an optical fiber that connects adjacent node devices and transmits a wavelength division multiplexed signal. An optical path arrangement search device that searches for a realistic optical path arrangement that is more suitable than the working optical path arrangement for traffic relayed by each of the logical topology acquisition means, the initial code group generation means, the best code selection means, Ending condition determining means, probabilistic code selecting means, code crossing means, mutation means, and next generation code group generating means.

  The logical topology acquisition unit is configured to use a plurality of optical paths as branches and a node device that terminates the plurality of optical paths as nodes for the set working optical path arrangement including a plurality of optical paths. From the path arrangement, a logical topology composed of branches and nodes and giving an ideal optical path arrangement is obtained. The initial code group generation means generates an initial code group composed of a plurality of gene codes including the node number given to each node device as an element. The best code selection means evaluates each of the plurality of gene codes belonging to the initial code group in association with the logical topology, and selects the best gene code as the best code. The end condition determining means determines whether or not the end condition is satisfied. Probabilistic code selection means, from the initial code group excluding the best code, as a result of evaluation, select a predetermined number of gene codes with a selection probability that the greater the probability that the better gene code will be selected, A probability selection code group is obtained. The code crossing means prepares a plurality of gene code pairs belonging to the probability selection code group, and crosses the gene code for each pair to obtain a cross code group. The mutation means causes a mutation in a part of the gene code belonging to the cross code group. The next generation code group generation means selects one gene code that has not been mutated from the cross code group and replaces it with the best code.

  According to another preferred embodiment of the optical path arrangement search device of the present invention, the optical path arrangement search device includes a logical topology acquisition unit, a random code generation unit, a best code selection unit, and an end condition determination unit.

  The logical topology acquisition unit is configured to use a plurality of optical paths as branches and a node device that terminates the plurality of optical paths as nodes for the set working optical path arrangement including a plurality of optical paths. From the path arrangement, a logical topology composed of branches and nodes and giving an ideal optical path arrangement is obtained. The random code generation means generates a random code including a node number given to each node device as an element. The best code selection means evaluates the random code in association with the logical topology, and when it is superior to the best code or the working optical path arrangement, newly selects the random code as the best code. The end condition determining means determines whether or not the end condition is satisfied.

  In order to achieve the above-described object, a program according to the present invention provides an optical communication network including a plurality of node devices and an optical fiber that connects adjacent node devices and transmits a wavelength multiplexed signal. An optical path arrangement search device that searches for a realistic optical path arrangement that is more suitable than the working optical path arrangement for traffic relayed by each of the above, a logical topology acquisition means, an initial code group generation means, and a best code selection means And termination condition determination means, probabilistic code selection means, code crossover means, mutation means, and next-generation code group generation means.

  The logical topology acquisition unit is configured to use a plurality of optical paths as branches and a node device that terminates the plurality of optical paths as nodes for the set working optical path arrangement including a plurality of optical paths. From the path arrangement, a logical topology composed of branches and nodes and giving an ideal optical path arrangement is obtained. The initial code group generation means generates an initial code group composed of a plurality of gene codes including the node number given to each node device as an element. The best code selection means evaluates each of the plurality of gene codes belonging to the initial code group in association with the logical topology, and selects the best gene code as the best code. The end condition determining means determines whether or not the end condition is satisfied. Probabilistic code selection means, from the initial code group excluding the best code, as a result of evaluation, select a predetermined number of gene codes with a selection probability that the greater the probability that the better gene code will be selected, A probability selection code group is obtained. The code crossing means prepares a plurality of gene code pairs belonging to the probability selection code group, and crosses the gene code for each pair to obtain a cross code group. The mutation means causes a mutation in a part of the gene code belonging to the cross code group. The next generation code group generation means selects one gene code that has not been mutated from the cross code group and replaces it with the best code.

  According to another preferred embodiment of the program of the present invention, the optical path arrangement search device is caused to realize a logical topology acquisition unit, a random code generation unit, a best code selection unit, and an end condition determination unit.

  The logical topology acquisition unit is configured to use a plurality of optical paths as branches and a node device that terminates the plurality of optical paths as nodes for the set working optical path arrangement including a plurality of optical paths. From the path arrangement, a logical topology composed of branches and nodes and giving an ideal optical path arrangement is obtained. The random code generating means generates a random code including a node number given to each node device as an element. The best code selection means evaluates the random code in association with the logical topology, and when it is superior to the best code or the working optical path arrangement, newly selects the random code as the best code. The end condition determining means determines whether or not the end condition is satisfied.

  According to the optical path arrangement search method, optical path arrangement search apparatus, and program of the present invention, since the optical path arrangement is set based on the observed traffic, it is possible to configure an optical path arrangement suitable for the current traffic. it can. In addition, since a new path arrangement is searched while maintaining the logical topology, for example, it is not necessary to determine the connectivity of the network, and the desired number of optical paths set with each node device as a start point or an end point Since it is possible to avoid determining whether or not the number of optical paths equal to the desired number can be set based on the size relationship with the number of internal interfaces of each node device, it is possible to efficiently search for path arrangements Become.

  Furthermore, when a genetic algorithm is used, the above search can be performed more easily.

  Further, when a genetic algorithm is not used, processing such as crossover and mutation is not required, and as a result, a suitable optical path arrangement can be searched with a simple configuration.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the positions and arrangement relationships of the respective constituent elements are merely schematically shown to the extent that the present invention can be understood. In the following, a preferred configuration example of the present invention will be described. However, the numerical conditions of each component are merely preferred examples. Therefore, the present invention is not limited to the following embodiment.

(Configuration of the first embodiment)
An optical communication network using WDM will be described with reference to FIG. FIG. 1 is a schematic configuration diagram for explaining an optical communication network. The optical communication network includes, for example, a plurality of node devices (hereinafter also referred to as N) 100 arranged in a lattice pattern and an optical fiber 102 that transmits wavelength multiplexed signals by connecting adjacent node devices 100. And is configured. An optical path is set in this optical communication network.

  Here, it is assumed that nine node devices 100 are arranged in a 3 × 3 grid. Each of these node devices 100 is assigned a unique identifier (ID). Here, the node ID (hereinafter also referred to as a node number) is a natural number from 1 to 9. For example, N1 indicates a node device whose node ID is 1.

  Although details of the configuration of each node device (N1 to N9) will be described later, each node device includes a relay unit having a router function connected to an external network, and an optical path switching unit that determines a transmission path of an optical signal. Yes.

  Adjacent node devices 100 are physically connected by an optical fiber 102. Each of these optical fibers is assigned a unique fiber ID. Here, the fiber ID is a natural number from 1 to 12. An optical fiber is represented by F, for example, F1 represents an optical fiber having a fiber ID of 1. The optical fibers F1 to F12 can communicate bidirectionally between adjacent node devices, and can transmit a wavelength-multiplexed optical signal obtained by multiplexing a plurality of optical signals having different wavelengths by wavelength multiplexing. In addition, it is good also as a structure which carries out bidirectional | two-way wavelength division multiplexing communication as one optical fiber connecting between node apparatuses one by one, and each optical fiber has a wavelength in one direction different from each other. It is good also as a structure which performs multiplex communication. As the optical fiber, any suitable conventionally known communication optical fiber can be used according to the setting such as the wavelength to be used. The connection relationship between these node devices and optical fibers is stored in advance in a storage unit or the like of the management device described later.

  Note that the configuration of the optical communication network such as the number and arrangement of the node devices and the connection relationship between the node devices is not limited to this example.

  The control network will be described with reference to FIG. FIG. 2 is a schematic configuration diagram for explaining the control network. The control network includes a node device (N1 to N9) 100, a management device 200 common to each node device 100, and a control line that transmits a control signal between the management device 200 and each node device (N1 to N9) 100. 202 is comprised. The control line 202 includes a setting line 204 and a measurement line 206. The setting signal generated by the management apparatus 200 is sent to N1 to N9 via the setting line 204. The traffic measurement results measured at N1 to N9 are sent to the management apparatus 200 via the measurement line 206.

  With reference to FIG. 3, an example of the configuration of the node device of the present invention will be described. FIG. 3 is a schematic configuration diagram for explaining the configuration of the node device.

  Each node device 100 includes an input unit 110, an optical path switching unit 130, an output unit 150, a relay unit 170, and a control unit 300.

  Now, assume that each node device 100 has four node devices adjacent to each other, and the adjacent node devices are connected to each other by optical fibers 102. Therefore, in this case, when attention is paid to a certain node device 100, four optical fibers 102 are connected to the node device 100. The node device 100 receives a wavelength multiplexed signal as an input wavelength multiplexed signal from one of the four other node devices adjacent to the node device 100, and sends the wavelength multiplexed signal to the remaining three other node devices. On the other hand, a wavelength multiplexed signal that is the same as or different from the input signal is output as an output signal. Here, an adjacent node device that transmits an input wavelength multiplexed signal to the node device is referred to as an input side node, and an adjacent node device that receives an output wavelength multiplexed signal from the node device is referred to as an output side node. The wavelength multiplexed signals received by the three output side nodes may be the same or different from each other.

  Since each node device 100 described above has the same configuration, the following description will be given focusing on one node device.

  A wavelength multiplexed signal is input to the input unit 110 as an input wavelength multiplexed signal from the input side node via the optical fiber 102. Here, it is assumed that the wavelength multiplexed signal is a carrier of four different wavelengths (hereinafter referred to as a single wavelength signal), but the number of multiplexed wavelengths is not limited to four. Absent.

  From the output unit 150 of the node device 100 focused on, the wavelength multiplexed signal is output as an output wavelength multiplexed signal via the optical fiber 102 to the output side node. Here, since there are four adjacent node devices, four optical fibers 102 are connected to the output unit 150.

  Note that although the number of adjacent node devices is described here as four, the number of adjacent node devices varies depending on the configuration of the optical communication network and the position of the node device in the optical communication network.

  The input unit 110 includes a set including the optical amplifier 112 and the duplexer 114 as a set. The number of sets is the same as the number of optical fibers 102 connected to the input unit 110. Here, the input unit 110 includes four optical amplifiers 112 and four duplexers 114. The wavelength multiplexed signals input from the respective node devices of the transmission sources through the corresponding optical fibers 102 are amplified by the optical amplifier 112 and then converted into single wavelength signals for each wavelength of λ1 to λ4 by the demultiplexer 114, respectively. After being demultiplexed, it is sent to an optical path switching unit 130 described later. Since the four optical fibers 102 are connected to the input unit 110, there are 16 single wavelength signals sent to the optical path switching unit 130. As the optical amplifier 112 used here, for example, an erbium-doped fiber amplifier (EDFA) can be preferably used. Further, as the duplexer 114, for example, an arrayed-waveguide grating (AWG) can be used.

  The output unit 150 is configured to include a set including the multiplexer 154 and the optical amplifier 152, which is the same number as the number of the optical fibers 102 connected to the output unit 150. Here, the output unit 150 includes four multiplexers 154 and four optical amplifiers 152. The single wavelength signal input from the optical path switching unit 130 is multiplexed, that is, wavelength-multiplexed, by the multiplexer 154 for each destination node device. The wavelength multiplexed signal obtained by wavelength multiplexing is amplified by the optical amplifier 152 and then output. Here, for example, an erbium-doped optical fiber amplifier (EDFA) can be preferably used as the optical amplifier 152. Further, as the multiplexer 154, for example, an arrayed waveguide diffraction grating (AWG) can be preferably used.

  The optical path switching unit 130 includes a termination unit 132 and an optical switch unit 140.

  The termination unit 132 has a function of switching a set state between a pass (cut-through) state and a termination (terminate) state for each of the 16 systems of single wavelength signals sent from the input unit 110. This optical path switching is performed in response to an optical path switching signal from the management apparatus 200. Here, the passing state is a state in which the single wavelength signal received from the duplexer 114 is sent directly to the optical switch unit 140 without being relayed by the relay unit 170. The termination state is a state in which the single wavelength signal received from the duplexer 114 is sent to the relay unit 170 and the single wavelength signal received from the relay unit 170 is sent to the optical switch unit 140, that is, the single wavelength signal is In this state, the relay unit 170 relays.

  In order to realize this function, the termination unit 132 includes, for example, any suitable well-known OADM (Optical Add Multiplexing) device or OXC (Optical Cross Connect) device in each of the optical paths through which 16 single-wavelength signals pass. Configured. Here, the termination unit 132 is configured to include 16 OADM devices (not shown), and each OADM device has a termination state and a passing state in response to an OADM control signal from the control unit 300. Switch. The termination unit 132 sends 16 single-wavelength signals to the optical switch unit 140 in the same manner as the single-wavelength signal sent from the input unit 110.

  The single-wavelength signal input to the optical switch unit 140 is wavelength-multiplexed by the output unit 150, and then passes through any one of the four optical fibers 102 connected to the output unit 150 to another adjacent node. Sent to the device. Since the switching of the optical path of the single wavelength signal is performed for each of the 16 systems of single wavelength signals, the optical switch unit 140 includes, for example, 16 1 × 4 optical switch devices. Here, the 1 × 4 optical switch device includes four output terminals, and any suitable well-known device that outputs an input single wavelength signal from any one of the output terminals can be used. Each of the output terminals of each 1 × 4 optical switch device is connected to the first to fourth multiplexers 154. Each 1 × 4 optical switch device responds to an optical path switching signal given from the management device 200 via the control unit 300, and sends an optical signal sent from the termination unit 132 to any of the first to fourth multiplexers 154. Output to one.

  The relay unit 170 includes a router 180, a conversion device 172 (172a, 172b, 172c, 172d), and a traffic measurement device 186.

  The first to fourth conversion devices 172a to 172d have a function of performing conversion from an electrical signal to an optical signal and the inverse conversion thereof. The four output terminals of each duplexer 114 correspond to the input terminals of the respective converters on a one-to-one basis. Similarly, the output terminals of the respective converters correspond to the four output terminals of each duplexer on a one-to-one basis. Each converter 172 converts the optical signal sent from the duplexer 114 into an electrical signal and sends it to the router 180.

  The router 180 includes an internal interface 182 (182a, 182b, 182c, 182d) and an external interface 184 as interfaces. The same number of internal interfaces 182 as the number of wavelengths multiplexed in the wavelength multiplexed signal are provided. Here, since the wavelength multiplexed signal in which four wavelengths are multiplexed propagates through the optical communication network as the optical signal, the router 180 has the first to fourth internal interfaces 182a to 182d as the four internal interfaces. Shall be provided.

  The router 180 specifies the path information and outputs the electrical signal received from the conversion device 172 or input from the external interface 184 from the first to fourth internal interfaces 182a to 182d and the external interface 184. A packet that is an electrical signal output from the external interface 184 is sent to the external network 190 via the traffic measuring device 186.

  The traffic measuring device 186 has a function of acquiring, as traffic, information on a source and destination such as an IP address from a packet and a transmission amount per unit time of the packet. It transmits to the management apparatus 200.

  The first to fourth conversion devices 172a to 172d are provided in a one-to-one correspondence with the first to fourth internal interfaces 182a to 182d. The first to fourth converters 172a to 172d convert electrical signals into single wavelength signals having different wavelengths. In addition, the 1st-4th converter can change the wavelength of a single wavelength signal. The single wavelength signals converted from the electrical signals by the first to fourth conversion devices 172a to 172d are sent to the optical path switching unit 130. Also, the first to fourth conversion devices 172 a to 172 d convert the single wavelength signal output from the optical path switching unit 130 into an electrical signal and send it to the router 180. These functions are used in a normal optical fiber communication system. Therefore, the 1st-4th conversion apparatus 172a-172d is realizable using arbitrary suitable conventionally well-known techniques. The numbers of internal interfaces 182 and conversion devices 172 are not limited to four.

  As the router 180, any suitable well-known one having a plurality of interfaces can be used. Of the plurality of interfaces included in the router 180, some may be used as the first to fourth internal interfaces 182a to 182d, and the rest may be used as the external interface 184.

  The setting signal sent from the management device 200 to each node device includes a route rewriting signal for rewriting route information included in the router 180, a termination control signal for the termination unit 132, and a switching control signal for the optical switch unit 140. The setting signal is sent from the management device 200 to the control unit 300 via the setting line 204. In response to receiving the setting signal, the control unit 300 transmits a route rewriting signal, a termination control signal, and a switching control signal to the router 180, the termination unit 132, and the optical switch unit 140, respectively.

  FIG. 4 is a schematic configuration diagram for explaining the management apparatus 200. The management device functions as an optimum optical path arrangement search device that searches for an optimum optical path arrangement. The management device 200 can use a known computer or the like that includes an MPU (Microprocessing Unit) 210, a storage unit 212, a transmission unit 214, a reception unit 216, and an input / output unit 218. The input / output unit 218 includes a known input device such as a keyboard and a mouse that are normally used in a computer, and a display device such as a display. As the storage unit 212, any suitable known storage device such as a hard disk is used. The MPU 210 can have a well-known configuration. In this example, the MPU 210 includes a central processing unit (CPU) 220, a RAM (Random Access Memory) 222 as a memory, and a ROM (Read Only Memory) 224. Yes.

  The control means 226 provided in the CPU 220 reads out a program recorded in the ROM 224 or the like so as to be readable, and executes the program, whereby the traffic monitoring means 230, the route change determination means 252 and the relay traffic are functioned as the CPU 220. Calculation means 254, logical topology acquisition means 262, initial code group generation means 264, code rearrangement means 266, best code selection means 268, end condition determination means 270, probabilistic code selection means 272, spare code generation means 274, spare The code crossing unit 276, the code restoration unit 278, the mutation unit 280, the next generation code group generation unit 282, and the path arrangement transition unit 290 are realized. Details of processing in each functional unit will be described later.

  The transmitter 214 and the receiver 216 can be any suitable known input interface. The traffic measurement results at the nodes (N1 to N9) sent to the management apparatus 200 are sent to the traffic monitoring means 230 via the receiving unit 216.

  The management device 200 generates a setting signal for changing the setting of the node device, and sends it to the nodes (N1 to N9) via the transmission unit 214 and the setting line 204.

(Operation of the first embodiment)
The operation of the first embodiment will be described with reference to FIGS. FIG. 5 is a diagram showing a processing flow in the management apparatus 200.

  The following procedure (processing) is performed by a functional unit in a computer, for example, the MPU here. Data and information obtained by these functional means are temporarily stored in the storage unit 212 or the RAM 222. In addition, the processing performed by these functional means may be performed by reading stored data or information, that is, referring to it. Each process for performing writing and reading for storage of these data and information is automatically performed by the control means 226 as known in the art, and the writing process and the reading process are not the gist of the present invention. Therefore, in the following description, description of these write (save) and read (reference) processes may be omitted.

  As is well known, the continuity of processing in each functional means of the computer is automatically performed by control means provided in the computer. Therefore, in the following description, the description of the point that the process of the next functional unit starts in response to the end of the process of the previous functional unit is omitted unless specifically described.

  Now, assume that this optical communication network system is in operation.

  The management device 200 searches for a suitable optical path arrangement in an optical communication network including a plurality of node devices and an optical fiber that connects adjacent node devices and transmits a wavelength division multiplexed signal. Make changes.

  Here, it is assumed that an optical path arrangement (active optical path arrangement) including a plurality of optical paths is actually set in the optical communication network. FIG. 6A is a diagram schematically showing this realistic optical path arrangement in the initial state, that is, the working optical path arrangement. In the optical communication network, an optical path is set between a specific start point and an end point. For example, in the example shown in FIG. 6A, N1 and N2, N1 and N5, N2 and N3, N2 and N6, N2 and N7, N3 and N6, N4 and N5, N4 and N7, N6 and N7, N6 And N9, N7 and N8, and N8 and N9, respectively. The setting status of the optical path in these working optical path arrangements is stored in the RAM 222 or the storage unit 212 as a path table so that it can be read and rewritten.

  It is necessary to change the optical path arrangement from the working optical path arrangement to an optical path arrangement suitable for the current traffic, and prior to this change, it is necessary to search how to set the optical path. This search process will be described in detail below.

  In step (hereinafter, step is represented by S) 10, the traffic monitoring means 230 monitors the traffic constantly or periodically at each node device of the optical communication network. The traffic monitoring means 230 is a traffic information table (hereinafter simply referred to as a traffic table) between the node devices as traffic information based on the measurement results of traffic received from the node devices (N1 to N9) constantly or periodically. To create). This traffic table is stored in the RAM 222 or the storage unit 212 so as to be readable.

  The traffic table will be described with reference to FIG. FIG. 7 is a diagram illustrating an example of a traffic table. In this traffic table, for each wavelength-multiplexed signal source, that is, each source node device, traffic to the wavelength-multiplexed signal transmission destination, ie, each destination node device, is shown in a matrix. Accordingly, when one node device is selected from each source node device and each destination node device, traffic from the source node device to the destination node device can be obtained. For example, the traffic from the node device N1 having a node ID of 1 as a source node device to the node device N2 having a node ID of 2 as a destination node device is 44.

  In S20, the route change determination unit 252 evaluates the working optical path arrangement in response to the completion of saving the traffic table, and determines whether or not to change the path to the new optical path arrangement. This evaluation is made based on whether or not the relay traffic in a certain node device exceeds the threshold value in the node device when the maximum amount of traffic that can be processed in the router included in the node device is used as the threshold value. This is because when the relay traffic exceeds the threshold value in the node device, congestion may occur in the node device including the router. The threshold is determined for each node device, and is recorded in advance in the storage unit 212, RAM 222, or ROM 224 of the management device 200 before the operation of the optical communication network is started.

  In comparing the traffic relayed by each node device and the threshold, first, the relay traffic calculation means 254 reads the traffic table and the path table recorded in the RAM 222 or the storage unit 212, and these tables are read out. Based on the above, the relay traffic in each node device is calculated. For example, in the working optical path arrangement shown in FIG. 6A, there is no optical path directly connecting N1 and N4, but there is an optical path directly connecting N1 and N5 and an optical path directly connecting N4 and N5. ing. In this case, in order to transmit a packet from N1 to N4, the packet can be transmitted using two optical paths from N1 to N5 and an optical path from N5 to N4. Here, it is assumed that the traffic relayed by N5 is traffic transmitted from N1 to N4 and traffic transmitted from N4 to N1. According to the traffic table shown in FIG. 7, the traffic transmitted from N1 that is the source node device to N4 that is the destination node device is eight. On the other hand, the traffic transmitted from the source node device N4 to the destination node device N1 is six. The traffics 8 and 6 are traffic relayed by the node device 5. The traffic A relayed by a certain node device (this is the self-node device), the traffic B having the self-node device as a transmission source, and the traffic C having the self-node device as a transmission destination are added (A + B + C) Thus, the relay traffic in the self-node device can be obtained. In this example, traffic B is the total value 118 of the column (row) of the transmission source node device 5 from the traffic table of FIG. 7, and traffic C is the total value 45 of the column (column) of the transmission destination node device 5. Further, since the traffic A is the above-described values 8 and 6, the sum (A + B + C) is 177. The calculation result of the relay traffic is recorded in a readable manner in the RAM 222, for example.

  Next, the relay traffic in each node device and the threshold value for each node device recorded in advance in the storage unit 212, RAM 222, or ROM 224 are read out and compared. This comparison is performed, for example, by taking a ratio to the threshold of relay traffic.

  When the ratio X / Y of the relay traffic X to the threshold value Y in a certain node device is larger than 1, that is, when the relay traffic exceeds the threshold value in the node device, there is a possibility that congestion occurs in the node device. In this case, in response to the determination, a search for the optimum path arrangement (hereinafter referred to as optimum path arrangement) in S30 is performed. On the other hand, when the relay traffic does not exceed the threshold value in any of the node devices (X / Y <1), the traffic of S10 is continuously monitored.

  The search for the optimal path arrangement in S30 is performed using a genetic algorithm, and includes steps S101 to S121 shown in FIG. FIG. 8 is a diagram showing a processing flow of the genetic algorithm.

  FIG. 9 is a diagram for explaining the genetic algorithm.

  In the logical topology acquisition process of S101, the logical topology acquisition unit 262 obtains a logical topology from the working optical path arrangement. The reason for introducing the logical topology is the determination of connectivity between the node devices constituting the network, the number of optical paths desired to be set with each node device as the start point or the end point, and the number of internal interfaces possessed by each node device. This is for avoiding the determination of whether or not the desired number of optical paths can be set based on the relationship of the size.

  Table 1 is a table showing the correspondence relationship between the node ID and the number of internal interfaces in the working optical path arrangement, which is obtained from the path table already described. In the working optical path arrangement, it is assumed that the number of optical paths set with each node device as a start point or an end point is equal to the number of internal interfaces of each node device.

  FIG. 6B is a diagram showing a logical topology for the working optical path arrangement schematically shown in FIG. This logical topology replaces the node device, which is the start point or the end point of each optical path, with the concept of “nodes”, and the optical path connecting the nodes with the concept of “branches”. This means an ideal optical path arrangement obtained for an optical path arrangement including a path. Each node is assigned a unique node ID. Here, the node ID is a natural number from 1 to 9. Further, the node is represented by P. For example, P1 represents a node whose node ID is 1. Here, the number of branches connected to each node is the order of the node. The order of these nodes is obtained by reading out the number of optical paths from which each node device is a start point or an end point from the path table described above. Table 2 is a table showing the correspondence between node IDs and orders for the logical topology shown in FIG. 6B, and this correspondence is stored in the storage unit 212 or the RAM 222. Here, the node IDs are arranged in ascending order with respect to the order.

  By the way, the reason for introducing this concept of “node” is as follows. As a process for obtaining a more suitable optical path arrangement from the current optical path arrangement, first, a new optical path that can be obtained by replacing another node apparatus at the position where each node apparatus is placed in the current optical path arrangement. Assume placement. The traffic relayed by each node device in the assumed new optical path arrangement is obtained. For this purpose, the concept of a node is introduced in the sense of mere position information in which a node device is replaced.

  In the initial code group generation process of S103, the initial code group generation means 264 generates a plurality of gene codes (also referred to as individuals in the following description) as the initial code group in response to the acquisition of the logical topology described above. (FIG. 9A). Here, the gene code table formed will be briefly described with reference to FIG. G1 to G20 in the leftmost column of the table represent gene code names. The topmost column in the table represents the element numbers of nine elements from 1 to 9 from left to right. Under each element number, a node ID corresponding to each gene code name is described. In the rightmost column of each gene code name, a numerical value indicating the fitness of the code is described. The fitness is an evaluation index specific to the genetic algorithm and can be identified with an objective function for a general optimization problem. Hereinafter, unless otherwise specified, evaluation indexes such as relay traffic are collectively referred to as the degree of conformity. Here, an example is shown in which a numerical value representing the sum of relay traffic in the entire internal network is used as the fitness. In this case, the smaller the fitness, the better the genetic code. Further, the traffic A described above may be used as the fitness.

  The reason for introducing this “gene code” is that there are many realistic optical path arrangements that satisfy the above-described logical topology relationship. This is because a suitable optical path arrangement is searched using a unique threshold value possessed by each node device.

  The gene code generated here has nine components. Each element uses numbers 1 to 9 without duplication. The nine elements of the genetic code correspond to the node IDs on a one-to-one basis. The number of gene codes to be generated can be arbitrarily set, but here is 20. Each gene code is generated by reading a random number table recorded in a readable manner in the ROM 224 or the like. In the following description, reading the random number table may simply generate a random number. The random number is generated regardless of the content of the acquired logical topology. Each gene code included in the initial code group is recorded in the RAM 222 so as to be readable.

  In S105, each of the gene codes is evaluated for the 20 gene codes included in the initial code group. The evaluation of the gene code is performed by calculating the fitness of a realistic optical path arrangement obtained by associating the gene code with the logical topology.

  First, association of the gene code with the logical topology will be described. In evaluating the optical path arrangement, the elements of the gene codes G1,..., G20 are associated with the node IDs from the gene code table read from the RAM 222. For example, according to FIG. 9A, when a node ID that is an element of the gene code G10 is expressed, the gene code G10 = {3, 1, 6, 5, 7, 4, 9, 8, 2}. These node IDs are rearranged in ascending order with respect to the number of internal interfaces. That is, referring to Table 1, since the number of internal interfaces of N1, N3 to N5, N8, and N9 is 2, and the number of internal interfaces of N2, N6, and N7 is 4, the rearranged code GN10 is represented by GN10. = {3, 1, 5, 4, 9, 8, 6, 7, 2}. The node ID which is each element of this GN10 and the node ID are made to correspond in order (Table 3). As a result, as shown in FIGS. 10A and 10B, a new optical path arrangement is obtained.

  FIG. 10B is a diagram showing a state in which the node ID and the node ID are associated with each other in the logical topology, that is, an ideal optical path arrangement. FIG. 10A is assumed to correspond to the gene code G10. A new realistic optical path arrangement is schematically shown. Comparing FIG. 6B and FIG. 10B, it can be seen that the relationship between the nodes and branches of both logical topologies is maintained, that is, the logical patterns of the optical paths are the same. Next, the relay traffic calculation means 254 calculates the relay traffic as the fitness.

  In the best code selection process of S107, the best code selection means 268 selects the best code from the initial code group. Here, the best code is the best code among the 20 gene codes, that is, the code with the smallest fitness. The best code is stored separately in the RAM 222 or the like. Here, G2 is selected as the best code. In order to determine whether or not the gene code is excellent, a fitness reference value is stored in advance in the ROM 224 or the like as a fitness criterion. The conforming reference value can be any suitable value depending on, for example, the sum of threshold values in the node devices belonging to the optical communication network. Here, if the matching reference value is set large, even if the matching degree is not sufficiently small, it is determined that the optimal path arrangement is set. If the matching reference value is set small, the processing time for searching the optimum optical path arrangement becomes long. .

  In S109, the end condition determination unit 270 determines whether or not the end condition is satisfied. As an end condition, for example, the degree of conformity of the best code is below the conformity reference value, the processing time of the genetic algorithm exceeds a preset processing time, or gene codes are generated for a preset generation It has been mentioned. If it is determined that any one of these termination conditions is satisfied, it is determined at that time that a more suitable and realistic optical path arrangement search has been performed, and the search is terminated.

  On the other hand, if the termination condition is not satisfied, then in the probabilistic code selection process of S111, the probabilistic code selection means 272 is superior or inferior from the 19 gene codes of the initial code group excluding the best code. A group of probability selection codes is obtained by selecting 20 gene codes with a selection probability based on the selection probability. Here, the smaller the fitness value, the greater the probability of being selected, and the greater the fitness value, the smaller the probability of being selected. In this case, the same gene code may be selected by overlapping, or there may be a gene code that is not selected (FIG. 9B).

  Next, crossover and mutation are caused for each gene code belonging to the probability selection code group. The crossover of gene codes will be described with reference to FIGS. 11 and 12 are diagrams for explaining the crossover of gene codes.

  The code crossover process includes steps S113, S115, and S117. In the code crossover process, a plurality of pairs of gene codes belonging to the probability selection code group are prepared, and the crossover code group is obtained by crossing the gene code for each pair.

  First, in S113, the preliminary code generation means 274 converts each gene code belonging to the probability selection code group by the order list C to generate a preliminary code. Here, the order list C is a list in which natural numbers 1 to 9 are arranged in order. The preliminary code defines what number in the ordered list each element of the genetic code corresponds to. The preliminary code is obtained in a one-to-one correspondence with the genetic code.

  Since the first element of the gene code G1 = {1, 6, 3, 7, 4, 8, 9, 2, 5} is 1, 1 is the first element in the ordered list C (0), so it is reserved. The first element of the code L1 is 1 (FIG. 11A).

  Next, 1 is removed from the order list C (0), and the following processing is performed. Since the second element of the genetic code G1 is 6, and 6 is the fifth element in the ordered list C (1) excluding 1, the second element of the spare code L1 is 5 (FIG. 11). (B)).

  Next, the following processing is performed by removing 6 from the order list C (1). The third element of the genetic code G1 is 3, and 3 is the second element in the ordered list C (2) obtained by subtracting 6 from the ordered list C (1), so the third element of the preliminary code L1 is 2 (FIG. 11C).

  Thereafter, when this operation is repeated, the preliminary code L1 = {1, 5, 2, 4, 2, 3, 3, 1, 1} is finally obtained (FIG. 11D).

  The same processing is performed for the gene code G2 = {3, 5, 1, 8, 6, 7, 4, 2, 9}, and the spare code L2 = {3, 4, 1, 5, 3, 3, 2, 1, 1} is obtained (FIG. 11E).

  Next, in S115, the spare code crossing means 276 crosses the selected spare codes. The 20 gene codes are divided into 10 pairs of 2 pairs. Here, a pair of spare codes L1 and L2 will be described (FIG. 11F). Thereafter, the spare code crossing means 276 determines the mating position. The mating position is determined by selecting one of natural numbers 1 to 9 by random numbers. For example, when 3 is obtained, the third element of the spare codes L1 and L2 is left, and the fourth and subsequent elements are exchanged. As a result, the spare mating code L1 ′ = {1, 5, 2, 5, 3, 3, 2, 1, 1} and L2 ′ = {3, 4, 1, 4, 2, 3, 3, 1, 1 } Is obtained (FIG. 11G). Similarly, spare codes are crossed for the other nine pairs.

  Next, in S117, the code restoration means 278 restores the gene code from the mating spare codes L1 ′ and L2 ′.

  Since the first element of the mating spare code L1 ′ is 1, 1 of the first element of the order code C (0) is set as the first element of the mating gene code G1 ′ (FIG. 12A).

Next, 1 is removed from the order list C (0), and the following processing is performed. The second element of the mating spare code L1 ′ is 5, and the fifth element 6 in the ordered list C (1) excluding 1 is set as the second element of the mating gene code G1 ′ (FIG. 12). (B)).

Next, the following processing is performed using the order list C (2) obtained by removing 6 from the order list C (1). The third element of the preliminary mating code L1 ′ is 2, and the second element 3 in the order list C (2) is set as the third element of the mating gene code G1 ′ (FIG. 12C). .

  Thereafter, when this operation is repeated, a mating gene code G1 ′ is finally obtained from the mating preliminary code L1 ′ (FIG. 12D).

  Similarly, a mating gene code G2 ′ is obtained from the mating preliminary code L2 ′ (FIG. 12E).

  This operation is performed on each pair, and 20 crossed gene codes are obtained as a crossing code group (FIG. 9C).

  Next, in the mutation process of S119, the mutation means 280 causes a mutation in the mating gene code. First, the probability of causing a mutation is set in advance. For example, the mutation probability is 0.03. At this time, random numbers are generated as real numbers ranging from 0 to 1. This random number is generated as many as the number of mating gene codes, and one random number corresponds to one mating gene code. The rightmost column in FIG. 9C shows the random number values given to the respective mating gene codes. Here, the mutation occurs when the random number corresponding to the gene code is 0.03 or less, which is the mutation probability. In the example shown in FIG. 9C, G2 ′ is mutated.

  Mutation is performed with two random numbers. For example, two different integer sets of 1 to 9 are generated by random numbers. Here, when h and k are selected as random numbers, the order from the h-th element to the k-th element of the gene code is reversed. s (h-1), s (h), s (h + 1), ..., s (k-1), s (k), s (k + 1) are s (h-1), s (k), s (K-1), ..., s (h + 1), s (h), s (k + 1). FIG. 9D shows a case where the mating gene code G2 ′ has been mutated. Here, the order from the fourth element to the seventh element is reversed.

  After crossover and mutation, in S121, the next generation code group generation unit 282 generates the next generation code group. In this process, one gene code that has not been mutated is randomly selected from the cross code group and replaced with the best code read from the RAM or the like. Here, it is assumed that the mating gene code G1 ′ and the best gene code are replaced (FIG. 9E).

  Next, by repeating the above process using this crossing code group as an initial code group, an excellent gene code is left in a later generation, and an optimal solution or a solution close to the optimal solution can be obtained.

  After searching for the optimum path arrangement in S30, the presence or absence of the optimum path arrangement is determined in S40. In this process, the route change determination unit 252 associates the gene code searched in the process of S30 with the logical topology by the code rearrangement unit 266 and then records the relay traffic and the storage device in advance in each node device. The threshold value is compared. Here, when the traffic relayed by each node device is smaller than the threshold, it is determined that there is an optimum path arrangement, and the optical path arrangement is changed in S50. On the other hand, if the traffic relayed by a certain node device is equal to or greater than the threshold value, it is determined that there is no optimal path arrangement, and the traffic of S10 is continuously monitored without changing the optical path arrangement. Even if the traffic to be relayed is equal to or greater than the threshold, if it is smaller than the traffic of the working optical path arrangement in the process of S20, it may be determined that there is an optimum path arrangement and the process of S50 may be performed.

  In S50, the route placement transition means 290 performs a transition process from the working optical path placement to the optimum path placement.

  According to the optical path arrangement search method, optical path arrangement search apparatus, and program of the first embodiment, the optical path arrangement is set based on the observed traffic, so that the optical path arrangement optimal for the current traffic is configured. be able to. In addition, since a new path arrangement is searched while maintaining the logical topology, for example, it is not necessary to determine the connectivity of the network, and the desired number of optical paths set with each node device as a start point or an end point Since it is possible to avoid determining whether or not the number of optical paths equal to the desired number can be set based on the size relationship with the number of internal interfaces of each node device, it is possible to efficiently search for path arrangements Become. Furthermore, the above search can be performed more easily by using a genetic algorithm.

(Configuration of Second Embodiment)
With reference to the drawings, the optimum optical path arrangement search device and the optimum optical path arrangement search method of the second embodiment will be described. In addition, the description which overlaps with 1st Embodiment is abbreviate | omitted.

  A management apparatus which is an optimum optical path arrangement search apparatus will be described with reference to FIG. Since the management apparatus of the second embodiment does not use a genetic algorithm, the management apparatus according to the second embodiment can be configured without a functional unit for executing the genetic algorithm. The management apparatus 201 of the second embodiment includes, as function means, a traffic monitoring means 230, a route change determination means 252, a relay traffic calculation means 254, a logical topology acquisition means 262, a code generation means 265, a best code selection means 269, and an end. A condition determination unit 271 and a route arrangement transfer unit 290 are realized.

(Operation of Second Embodiment)
The processing of the management apparatus 200 is the same as that of the first embodiment described with reference to FIG. The second embodiment is different from the first embodiment in that the optimum path search in S30 is performed by a random algorithm.

  The search for the optimal path arrangement in S30 is performed using a random algorithm, and includes steps S101 to S110. FIG. 14 is a diagram illustrating a processing flow of the random algorithm.

  In the logical topology acquisition process of S101, the logical topology acquisition means 262 acquires the logical topology.

  In the random code generation process of S104, the code generation means 265 generates a random number to generate a random code. The random code has nine elements and uses numbers 1 to 9 one by one. Nine elements included in the random code correspond to the node ID.

  In the fitness calculation process in S106, the random code is evaluated in association with the logical topology. First, the code rearranging unit 266 rearranges the node IDs that are elements of the random code in ascending order with respect to the number of interfaces. Next, the relay traffic calculation means 254 calculates the fitness.

  In the best code selection process of S108, the best code selection means 269 stores the random code as the best code in the RAM 222 or the like when the suitability is smaller than the suitability of the working optical path arrangement.

  Next, in S110, the end condition determination unit 271 determines the end condition. When the end condition is satisfied, the processes of S40 and S50 are performed, and when the end condition is not satisfied, the code generation process of S104 is performed. For example, when the best code fit is below a threshold, the processing time of a random algorithm exceeds a preset processing time, or when a predetermined number of random codes are generated If the condition is satisfied, it is determined that the end condition is satisfied.

  According to the optical path arrangement search method, optical path arrangement search apparatus, and program of the second embodiment, the optical path arrangement is set based on the observed traffic as in the first embodiment. A suitable optical path arrangement can be configured. Further, since no genetic algorithm is used, processing such as crossover and mutation is not required, and as a result, it is possible to search for an optical path arrangement with a simple configuration.

It is a schematic block diagram of an optical communication network. It is a schematic block diagram of a control network. It is a schematic block diagram of a node apparatus. It is a schematic block diagram (the 1) of a management apparatus. It is a figure which shows the processing flow in a management apparatus. It is a figure which shows initial stage optical path arrangement | positioning. It is a figure which shows a traffic table. It is a figure showing the processing flow of a genetic algorithm. It is a figure for demonstrating a genetic algorithm. It is a figure which shows the optical path arrangement | positioning after a change. It is FIG. (1) for demonstrating crossing of a genetic code. It is FIG. (2) for demonstrating crossing of a genetic code. It is a schematic block diagram (the 2) of a management apparatus. It is a figure which shows the processing flow of a random algorithm.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Node apparatus 102 Optical fiber 110 Input part 112,152 Optical amplifier 114 Demultiplexer 130 Optical path switching part 132 Termination part 140 Optical switch part 150 Output part 154 Multiplexer 170 Relay part 172a-172d Converter 180 Router 182a-182d Inside Interface 184 External interface 200 Management device 202 Control line 204 Setting line 206 Measurement line 210 MPU
212 storage unit 214 transmission unit 216 reception unit 218 input / output unit 220 CPU
222 RAM
224 ROM
226 Control unit 230 Traffic monitoring unit 252 Route change determination unit 254 Relay traffic calculation unit 262 Logical topology acquisition unit 264 Initial code group generation unit 265 Code generation unit 266 Code rearrangement unit 268, 269 Best code selection unit 270, 271 End condition Judgment means 272 Probabilistic code selection means 274 Preliminary code generation means 276 Preliminary code crossover means 278 Code restoration means 280 Mutation means 282 Next-generation code group generation means 290 Path allocation transition means 300 Control unit

Claims (6)

Traffic that is relayed by each of the plurality of node devices using a genetic algorithm in an optical communication network comprising a plurality of node devices and an optical fiber that connects adjacent node devices and transmits wavelength multiplexed signals In searching for a realistic optical path arrangement that is more suitable than the working optical path arrangement,
The logical topology acquisition means uses the plurality of optical paths as branches and the node device that terminates the plurality of optical paths as nodes with respect to the set working optical path arrangement including a plurality of optical paths that have been set. A logical topology acquisition process for obtaining a logical topology composed of the branches and nodes and giving an ideal optical path arrangement from the working optical path arrangement;
An initial code group generating means for generating an initial code group composed of a plurality of gene codes, the node including a node number given to each of the node devices as an element;
The best code selection means evaluates each of the plurality of gene codes belonging to the initial code group in association with the logical topology, and selects the best gene code for setting the realistic optical path arrangement. Best code selection process to select as an excellent code,
A probabilistic code selection means selects a predetermined number of gene codes from the initial code group excluding the best code with a selection probability that a probability that a better gene code is selected as a result of the evaluation is larger. A stochastic code selection process to obtain a probability selection code group,
Code crossover means preparing a plurality of gene code pairs belonging to the probability selection code group, crossing the gene code for each pair, a code crossover process of obtaining a crossover code group,
A mutation process in which a mutation means causes a mutation in a part of the genetic code belonging to the crossing code group;
Next-generation code group generation means selects one gene code that has not been mutated from the cross-code group and replaces the selected gene code with the best code. And performing the best code selection process using the cross code group as an initial code group. In an optical communication network that includes a plurality of node devices and an optical fiber that connects adjacent node devices and transmits wavelength multiplexed signals, it is preferable to the working optical path arrangement for traffic relayed by each of the plurality of node devices. In searching for a realistic light path arrangement,
The logical topology acquisition means uses the plurality of optical paths as branches and the node device that terminates the plurality of optical paths as nodes with respect to the set working optical path arrangement including a plurality of optical paths that have been set. A logical topology acquisition process for obtaining a logical topology composed of the branches and nodes and giving an ideal optical path arrangement from the working optical path arrangement;
A random code generating means for generating a random code, the random code generating means including a node number given to each of the node devices as an element;
When the best code selection means evaluates the random code in association with the logical topology and is superior to the working optical path arrangement to set the realistic optical path arrangement, the random code is selected. An optical path arrangement search method characterized by performing a best code selection process for selecting as a best code. Traffic that is relayed by each of the plurality of node devices using a genetic algorithm in an optical communication network comprising a plurality of node devices and an optical fiber that connects adjacent node devices and transmits wavelength multiplexed signals An optical path arrangement search device that searches for a realistic optical path arrangement that is more suitable than the working optical path arrangement,
The working optical path arrangement by setting the plurality of optical paths as branches and a node device that terminates the plurality of optical paths as a node with respect to the set working optical path arrangement including a plurality of optical paths. From the above, a logical topology acquisition means for obtaining a logical topology composed of the branches and nodes and giving an ideal optical path arrangement;
Initial code group generation means for generating an initial code group composed of a plurality of gene codes, including a node number given to each of the node devices as an element;
Each of a plurality of gene codes belonging to the initial code group is evaluated in association with the logical topology, and the best gene code for selecting the best optical code is selected as the best code. Code selection means;
An end condition determining means for determining whether or not the end condition is satisfied;
From the initial code group excluding the best code, as a result of the evaluation, a probability selection code group is selected by selecting a predetermined number of gene codes with a selection probability that the probability that a better gene code is selected becomes larger. Probabilistic code selection means to obtain;
Preparing a plurality of gene code pairs belonging to the probability selection code group, crossing the gene code for each pair, code crossing means to obtain a cross code group;
Mutation means for causing mutation in a part of the genetic code belonging to the cross code group,
An optical path arrangement search device comprising: a next generation code group generation means for selecting one gene code that has not been mutated from the cross code group and replacing it with the best code. In an optical communication network that includes a plurality of node devices and an optical fiber that connects adjacent node devices and transmits wavelength multiplexed signals, it is preferable to the working optical path arrangement for traffic relayed by each of the plurality of node devices. An optical path arrangement search device that searches for a realistic optical path arrangement,
By setting the plurality of optical paths as branches and a node device that terminates the plurality of optical paths as nodes, with respect to the set working optical path arrangement including a plurality of optical paths, A logical topology acquisition means configured to obtain a logical topology composed of the branches and nodes and giving an ideal optical path arrangement;
Random code generating means for generating a random code, including a node number given to each of the node devices as an element;
When the random code is evaluated in association with the logical topology and is superior to the best code or the working optical path arrangement for setting the realistic optical path arrangement, the random code is newly selected as the highest code. Best code selection means to select as an excellent code,
An optical path arrangement search apparatus comprising: an end condition determining unit that determines whether or not an end condition is satisfied. Traffic that is relayed by each of the plurality of node devices using a genetic algorithm in an optical communication network comprising a plurality of node devices and an optical fiber that connects adjacent node devices and transmits wavelength multiplexed signals In the optical path arrangement search device for searching for a realistic optical path arrangement that is more suitable than the working optical path arrangement,
The working optical path arrangement by setting the plurality of optical paths as branches and a node device that terminates the plurality of optical paths as a node with respect to the set working optical path arrangement including a plurality of optical paths. From the above, a logical topology acquisition means for obtaining a logical topology composed of the branches and nodes and giving an ideal optical path arrangement;
Initial code group generation means for generating an initial code group composed of a plurality of gene codes, including a node number given to each of the node devices as an element;
Each of a plurality of gene codes belonging to the initial code group is evaluated in association with the logical topology, and the best gene code for selecting the best optical code is selected as the best code. Code selection means;
An end condition determining means for determining whether or not the end condition is satisfied;
From the initial code group excluding the best code, as a result of the evaluation, a probability selection code group is selected by selecting a predetermined number of gene codes with a selection probability that the probability that a better gene code is selected becomes larger. Probabilistic code selection means to obtain;
Preparing a plurality of gene code pairs belonging to the probability selection code group, crossing the gene code for each pair, code crossing means to obtain a cross code group;
Mutation means for causing a mutation in a part of the genetic code belonging to the cross code group,
A program for optical path arrangement search, characterized by realizing a next generation code group generation means for selecting one gene code not mutated from the cross code group and replacing it with the best code. In an optical communication network that includes a plurality of node devices and an optical fiber that connects adjacent node devices and transmits wavelength multiplexed signals, it is preferable to the working optical path arrangement for traffic relayed by each of the plurality of node devices. In an optical path arrangement search device that searches for a realistic optical path arrangement,
The working optical path arrangement by setting the plurality of optical paths as branches and a node device that terminates the plurality of optical paths as a node with respect to the set working optical path arrangement including a plurality of optical paths. From the above, a logical topology acquisition means for obtaining a logical topology composed of the branches and nodes and giving an ideal optical path arrangement;
Random code generating means for generating a random code, including a node number given to each of the node devices as an element;
When the random code is evaluated in association with the logical topology and is superior to the best code or the working optical path arrangement for setting the realistic optical path arrangement, the random code is newly selected as the highest code. Best code selection means to select as an excellent code,
What is claimed is: 1. A program for optical path arrangement search, comprising: an end condition determining unit that determines whether or not an end condition is satisfied.

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