Abstract: A dispersion compensation design system includes a changing unit setting a changed value for the amount of dispersion compensation for a span connecting nodes constituting an optical network; a path classification unit determining whether respective paths in the optical network are capable of transmission with the changed value and classifying one or more of the paths as second category paths based on the determination results; an updating unit updating the amount of dispersion compensation with the changed value if the number of the second category paths in the latest classification result is less than the number of the second category paths in the retained previous classification result; and a repeating unit that, if not all of the paths in the optical network are capable of transmission, prevents use of combinations of amounts of dispersion compensation applied to the spans in the second category paths in the latest classification result.

Abstract: A dispersion compensation design system includes a segment dividing unit to divide an optical network into segments of a linear network or a ring network, a path classifying unit to classify one of paths of the optical network, as a specific type path, the one of the paths being incapable of transmitting an optical signal and contained in a longer path having a route longer than that of the one of the paths and capable of transmitting the optical signal, a segment reconfiguration unit to reconfigure the segments so as to maximize a number of the specific type paths, a dispersion compensation amount computing unit to compute a dispersion compensation amount in any of spans of the optical network so as to minimize the number of the specific type paths within the reconfigured segment, and an update unit to update the dispersion compensation amount with the computed dispersion compensation amount.

Abstract: A network design apparatus includes: a first processing unit configured to select one or more paths between nodes in response to a request for a bandwidth between pairs of nodes in a network to determine working communication routes and protecting communication routes connecting the pairs of nodes, and estimate a number of communication lines in the selected path; and a second processing unit configured to allocate logical channels of the communication lines to the working communication routes and the protecting communication routes based on the requested bandwidth, wherein the first processing unit determines the protecting communication routes while permitting the sharing of the path, and the second processing unit allocates a common logical channel to one or more communication routes, out of the protecting communication routes, that share the path and are not simultaneously used when a failure occurs in the working communication routes.

Abstract: A network design apparatus includes an input unit configured to receive network information that indicates nodes connected by optical transmission paths and path information that indicates paths between the nodes; an design unit configured to perform, based on the network information and the path information, wavelength dispersion compensation design using a constraint condition that a path whose span count is larger than a span count of another path that does not satisfy a transmission condition does not satisfy the transmission condition; and an output unit configured to output a result obtained by the design unit.

Abstract: There is provided an apparatus and method for allocating devices to a communication route. Network topology information and device information including a device-cost assigned to each of candidate-devices allowed to be allocated to a plurality of segments on the communication route are provided. An integer/linear programming problem is generated to obtain a feasible device-allocation, and an objective function for calculating an objective function value is defined. A sequence of feasible device-allocations are generated by sequentially generating a next feasible device-allocation from a current feasible device-allocation while improving an objective function value until the objective function value is not improved any more, and the last one of the sequence of feasible device-allocations is determined to be an optimum device-allocation.

Abstract: An optical network designing device that designs a path of an optical network that includes an asymmetric optical hub site, comprising: a path calculating unit that calculates a requested traffic path without a limit to a number of connections of the asymmetric optical hub site; a violation determining unit that determines whether a limit to the number of connections is violated in the asymmetric optical hub site through which the traffic path calculated by the path calculating unit passes; a removal selecting unit that selects a removal connection to be removed from the determined asymmetric optical hub site when the violation determining unit determines that the limit to the number of connections is violated; and a path recalculating unit that recalculates a traffic path that passes through the asymmetric optical hub site from which the removal connection selected by the removal selecting unit has been removed.

Abstract: A network design apparatus includes a storage unit configured to store network topology information indicating a connection relationship between a plurality of nodes in a network in which the plurality of nodes are connected to each other by a link and demand information indicating a demand including a starting point node, an ending point node, a route, and the number of the demands, and a control unit configured, based on the network topology information and the demand information, to take out a certain number of nodes from the sorted nodes having the higher rank and generate combination candidates of transmission paths in which the starting point node, the ending point node, and the certain number of nodes are set as terminal points with regard to the respective demands, and determine a combination of the transmission paths that accommodate the demand from the combination candidates of the transmission paths.

Abstract: A resource reservation apparatus reserving a resource on a second and third route connecting a start with end node of the first route over a network having a resource on a first route, includes a resource controller for defining a fourth route including a link obtained by excluding a common link between the first and second route and between the first and third route from a link included in the first, second or third route, a message generator for generating a message used for reserving a resource of the link included in the fourth route and transmitting the message to a node on the fourth route, and a message processor for transmitting a message used for generating the second and third route from the resource on the first route and on the fourth route reserved by the message generator to a node included in the second or third route.

Abstract: A CPU collects count information of NW-side/CL-side communication cards when IFCs with plural types that store NW-side/CL-side communication cards to be designed are accommodated in two or more shelves. The CPU further collects card information of the number of slots used by IFCs, shelf information of the maximum number of slots that can be accommodated by IFCs in the shelf, and correspondence information of correspondence relationship when between-shelf-intercommunication between different NW-side communication cards is performed. The CPU further collects communication limit capacity to be used for intercommunication between the shelves. The CPU generates an integer planning model for assigning IFCs to be designed into two or more minimum shelves on the basis of card information, count information, shelf information, correspondence information, and communication limit capacity.

Abstract: An apparatus searches for one or more first routes coupling starting and ending point nodes in a communication network including an asymmetry node, based on topology information indicating a connection relationship between nodes on the communication network. The apparatus determines, for each of the one or more first routes, whether or not signals are transmittable between the starting and ending point nodes under path restriction imposed on the asymmetry node, based on asymmetry-node information indicating the path restriction imposed on the asymmetry node. The apparatus determines a second route that has a minimum sum of link costs among one or more third routes for which it is determined that signals are transmittable between the starting and ending point nodes under the path restriction imposed on the asymmetry node, based on cost information storing a link cost of a link connecting each pair of adjacent nodes on the communication network.

Abstract: In an apparatus for supporting designing of an optical network including a plurality of nodes and links which connect the plurality of nodes: a storage stores information indicating distances of the links and information indicating amounts of chromatic dispersion in the links; and a path selection unit selects a path for use in transmission of an optical signal, from among a plurality of paths each extending from a start node to a destination node, by reference to the storage. The path selection unit selects the path for use in transmission on the basis of deviations of amounts of chromatic dispersion accumulated by transmission to respective nodes on each of the plurality of paths, from reference amounts at the respective nodes, and the reference amounts at the respective nodes on each of the plurality of paths are determined according to distances from the start node to the respective nodes.

Abstract: An optical network design apparatus includes a memory and a processor. The memory stores a connection limit corresponding to the number of connections between ports. The processor provisionally designs a traffic path across an optical network independently of a connection limit of an asymmetric optical hub, calculates a penalty allowance with respect to the penalty limit of the traffic path, calculates an additional penalty caused on a detour path derived by replacing a port with a replacement port in the asymmetric optical hub, and if an asymmetric optical hub is included in the detour path, generates asymmetric optical hub information about the included asymmetric optical hub, generates, based on the connection limit, penalty allowance, additional penalty, and asymmetric optical hub information, a constraint condition for adopting the traffic path satisfying the connection limit and penalty limit, and calculates the traffic path by mathematical programming under the constraint condition.

Abstract: A demand accommodation design system for accommodating a demand specifying a signal transmission route from a start-point node to an end-point node within an optical network includes an analytical unit to acquire at least one optical path candidate for minimizing cost of the optical network by solving an objective function incorporating cost of optical path candidates by bandwidth, the optical path candidate being a candidate for an optical path composing a demand, and a mathematical programming problem employing a constraint condition incorporating a bandwidth of an optical path pattern candidate connecting the start-point node and the end-point node of the demand and a bandwidth of the acquired optical path candidate, the optical path pattern candidate being the acquired optical path candidate itself or being obtained by combining the optical path candidates, and an allocation unit to allocate the demand to the acquired optical path candidate to accommodate the demand.

Abstract: An apparatus for designing an optical network having nodes, includes: a parameter holding unit which holds values of one or more optical-transmission parameters corresponding to one or more components constituting the optical network; a part generation unit which generates design candidates for a part to be arranged in each of one or more spans between the nodes so that each of the design candidates contains at least one of the one or more components; a part selection unit which makes a selection, for each of the one or more spans, of one of the design candidates which has at least one value of at least one of the one or more optical-transmission parameters satisfying a design condition; and a construction control unit which constructs the optical network by combining one or more parts each of which is selected by the part selection unit.

Abstract: The first route searching unit searches among multiple routes from a start node toward a goal node for a first route by using topology information. The topology information changing unit changes the topology information by excluding the first route from the multiple routes and setting, to configuration links constituting the first route, additional links whose direction is opposite to that of the configuration links. The port information changing unit changes port information such that communication in a direction from the goal node toward the start node is permitted in the configuration links and the additional links. The second route searching unit searches for a second route by using the changed topology information and the changed port information. The redundant route searching unit searches for a pair of redundant routes by eliminating the configuration links that overlap on the first route and the second route.

Abstract: A chromatic dispersion compensation design system includes: an input unit that inputs information of an optical network having a plurality of nodes optically coupled to each other via an optical transmission path; an allowable range determining unit that determines an allowable range of a residual chromatic dispersion with respect to every wavelength path of a plurality of signals from a starting node to a terminal node, based on the information of the optical network; and a calculation unit that calculates a wavelength path capacity in the allowable range of the residual chromatic dispersion, in view of a chromatic dispersion variability of each optical element in the optical network.

Abstract: A computer-readable recording medium having stored therein a program for causing a computer to execute a process includes accepting a start node and finish node that are both terminuses for a circuit that is to be accommodated in a transmission network that includes a plurality of transmission lines, selecting, from the plurality of transmission lines, a transmission line whose arrangement order of arranging a plurality of nodes on the transmission line in an order of an indicated direction determined for the transmission line is the same as an order of the plurality of nodes determined in accordance with a cost order of the shortest path from a node at a terminus of the circuit to the plurality of nodes, and searching for a path from the circuit's start node to the circuit's finish node via the selected transmission line in the order of the indicated direction.

Abstract: There is provided topology information including connection states among nodes in a network, and port information including restriction conditions on connectivity among ports within a restricted node. A path search apparatus finds a first path having the minimum total link-cost among a plurality of paths. The topology information is changed so that the first path is not searched for as a path having the minimum total link-cost among the plurality of paths, and the port information is changed based on a port connectivity change rule. Then, the path search apparatus finds a second path different from the first path, based on the changed port information and the changed topology information, and reconfigures a pair of link-disjoint paths satisfying the restriction conditions imposed on the restricted node, by removing a link shared by both the first and second paths from the original topology information.

Abstract: A network design device includes a bypass number setting unit setting the number of bypass node; a loss calculating unit calculating a reference loss; a graph generating unit generating a graph having a variation value obtained based on a difference between a transmission loss of a link coupling nodes to each other and the reference loss; a path detecting unit detecting a minimum-variation-path in which sum of each variation value from a start point to an end point of the graph is minimum; and a comparing unit comparing a calculation OSNR and a reference OSNR, the calculation OSNR being obtained by a calculation from a start point to an end point assuming that an optical amplifier is located on a node other than a bypass node on the minimum-variation-path, wherein the bypass number setting unit changes the number of bypass node based on a result of the comparing unit.

Abstract: A method for determining a value of chromatic dispersion compensation in an optical network including a plurality of nodes connected by at least one transmission line, the plurality of nodes including a plurality of dispersion compensators, the optical network including a plurality of wavelength paths between the optional nodes, the method includes determining a compensation value of the dispersion compensators in the optical network by the computer, the compensation value selecting that an error between the object value of the residual chromatic dispersion in accordance with of the first end node of the first path and the permissible value of the residual chromatic dispersion of the first end node of the first path is least, and the value of the residual chromatic dispersion of the first end is in the permissible value of the residual chromatic dispersion of the second end node of the second path.