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:
An optical communicating apparatus that is connected to another optical communicating apparatus by a two-core optical transmission path includes: a one-core optical transmission path that passes an optical signal transmitted from an optical transmitter/receiver performing one-core bilateral communication and an optical signal transmitted to the optical transmitter/receiver in an opposite direction; a transmitting unit that transmits the optical signal transmitted from the optical transmitter/receiver through the one-core optical transmission path, to the other optical communicating apparatus through a first core of the two-core optical transmission path; and a receiving unit that receives the optical signal transmitted from the other communicating apparatus through a second core of the two-core optical transmission path, and passes the received optical signal to the one-core optical transmission path.
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:
In an optical network design apparatus, a constraint setter sets a first constraint that one of alternative values given beforehand is selected as the dispersion compensation amount of each node, sets a first margin value that assumes a nonnegative value, sets a second constraint that the first margin value is equal to or greater than the difference between the residual dispersion and the lower bound of an allowable range, sets a second margin value that assumes a nonnegative value, and sets a third constraint that the second margin value is equal to or greater than the difference between the upper bound of the allowable range and the residual dispersion. A calculation controller generates an objective function including the first, second and third constraints and including a summation of the first and second margin values for all paths, and derives a solution that minimizes the objective function.
摘要:
A wavelength selecting apparatus includes a wavelength selecting filter and that a monitoring filter are similar acousto-optic tunable filters; a light source that outputs light having a specific wavelength to the monitoring filter; a light receiving unit that detects a wavelength of light that has passed the monitoring filter; and a control unit that outputs, to the wavelength selecting filter, a control signal having a control frequency to selectively pass light of a desirable wavelength. The light source includes a light emitting element that emits light of a wide wavelength band; and an optical filter having at least two transmission bands through which the light passes to the monitoring filter. The control unit, based on at least two wavelengths of the light output by the light source, outputs a control signal having a control frequency corresponding to the desirable wavelength.
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.