摘要:
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.
摘要:
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.
摘要:
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. The next feasible device-allocation is generated from the current feasible device-allocation by replacing a basic candidate-device with an alternative candidate-device selected based on reduced-costs calculated for nonbasic candidate-devices.
摘要:
A network design apparatus includes an information acquiring unit acquiring optical network information, a section dividing unit dividing an optical network into linear sections, a combination candidate determining unit determining candidates for combinations of various kinds of optical transmission equipment to be placed in each station in each of the linear sections, a noise amount upper limit determining unit determining an upper limit to the amount of noise allowed for each wavelength path, and an equipment placement unit solving an integer programming problem having an objective function that minimizes the cost of the optical transmission equipment and OEO regenerators, subject to the constraints that one optical transmission equipment combination is selected for each linear section and that the number of OEO regenerators necessary for each wavelength path is determined by the cumulative amount of noise of the wavelength path and the noise upper limit determined for the wavelength path.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
A residual chromatic dispersion target value at a terminal node is set for each wavelength path, and also, candidates of a dispersion compensation amount settable in each chromatic dispersion compensation module on an optical network are set, and further, computation processing is executed for selecting the dispersion compensation amount in each chromatic dispersion compensation module from the candidates so that the sum of errors between the residual chromatic dispersion amounts and the set residual chromatic dispersion target values at the terminal nodes for all of wavelength paths becomes minimum. As a result, for each wavelength path on the optical network, the dispersion compensation amount in each chromatic dispersion compensation module can be designed in optimum so as to satisfy the desired optical signal quality at the terminal node, while considering the residual chromatic dispersion during the transmission.
摘要:
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. The next feasible device-allocation is generated from the current feasible device-allocation by replacing a basic candidate-device with an alternative candidate-device selected based on reduced-costs calculated for nonbasic candidate-devices.
摘要:
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.