Fujitsu Corporation

Tomohiro Hashiguchi

Kazuyuki Tajima

Yutaka Takita

Toru Katagiri

Takashi Toyomaki

Motoyoshi Sekiya

Masatake Miyabe

A wavelength reallocation assisting method provides information relating to wavelength allocation to optical lines in a wavelength division multiplexing optical network in which a plurality of nodes are connected by optical fibers. The wavelength reallocation assisting method includes: outputting first allocation state information that indicates a sum of bandwidths of respective wavelength slots used by at least one of the optical lines among a plurality of wavelength slots that are available in the wavelength division multiplexing optical network; and outputting second allocation state information that indicates a maximum value of individual used bandwidths obtained with respect to the respective optical fibers, each of the individual used bandwidths indicating a sum of bandwidths of wavelength slots allocated to corresponding optical lines established in a corresponding optical fiber.

Method and device for assisting wavelength reallocation in wavelength division multiplexing optical network

A network design device includes a processor. The processor determines a second wavelength allocation based on a first wavelength allocation that indicates a wavelength allocation for a plurality of optical lines established in a wavelength division multiplexing optical network. The processor searches for a disconnection target optical line that is requested to be disconnected in order to realize a transition from the first wavelength allocation to the second wavelength allocation from among the plurality of optical lines. The processor generates procedure information that indicates a procedure of the transition from the first wavelength allocation to the second wavelength allocation based on a difference between the first wavelength allocation and the second wavelength allocation and a searched disconnection target optical line.

Device and method for designing optical network

A processor executes the following processes. An obtainment process obtains a first number of lines, which represents a number of lines that are deleted after changing, among lines that pass through the same line route. An extraction process extracts a line for which a first demand, which is accommodated before and after changing, does not exist. The extraction process further extracts lines in descending order of a band of the first demand from among lines including first demands until a total number of extracted lines reaches the first number of lines when the number of the extracted lines is smaller than the first number of lines. Then, a fixation process fixes a first demand accommodated in a line that has not been extracted. A deletion process deletes the extracted lines. A determination process determines an order of changing line routes of demands.

Demand accommodation changing order determination method

A network design apparatus includes: a memory; and a processor coupled to the memory and configured to execute: accommodation design processing of, based on a traffic of a protection-applied or protection-unapplied first link in a first layer, generating a protection-unapplied second link in a second layer lower than the first layer, and generating a working path and a protection path of the first link on a network configured of the second link, and protection application processing of, based on the protection-unapplied second link and the working path and the protection path of the first link that are generated in the accommodation design processing, selecting or generating a protection-applied link in the second layer from the protection-unapplied second link.

Network design apparatus, network design method, and storage medium storing network design program

A transmission device is used for a network that includes a plurality of working paths and a plurality of protection paths bypassing a relevant working path for each working paths. The transmission device includes a data plane unit that transmits and receives data to and from other transmission devices; and a signaling processing unit that performs switching, when a signaling message requesting activation to switch to a first protection path corresponding to a first working path is received, from the first working path to the first protection path, wherein, when the first working path is configured as a subset of a second working path and a second protection path corresponding to the second working path is provided, the signaling processing unit performs switching from the first working path to the first protection path and performs switching from the second working path to the second protection path.

Transmission device, network designing device, activation method, and network designing method

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. The CPU executes the integer planning model and outputs a design solution for accommodation design for assigning IFCs into the minimum shelves.

Recording medium, accommodation design device, and accommodation design method

An apparatus determines, in response to demands for traffic between nodes in a network transmitting wavelength-multiplexed optical-signals, routes each providing connection between nodes, and estimates, for each link, communication-channels to be established, based on a wavelength-constraint condition that the number of communication-channels to be established be not greater than a first upper-limit for available optical-signal wavelengths. The apparatus assigns wavelengths to the communication-channels, based on a system-constraint condition that the number of optical-signals having an identical wavelength and redundantly usable be not greater than a second upper-limit for available transmission-systems. The apparatus determines a target-number of wavelengths for reducing a required number of transmission-systems. The apparatus changes the wavelength-constraint condition by defining the first upper-limit as the target-number and changes the system-constraint condition by reducing the second upper-limit, and re-estimates communication-channels based on the changed wavelength-constraint condition and re-assigns wavelengths based on the changed system-constraint condition.

Apparatus and method for designing a network transmitting wavelength multiplexed optical signals

A network design apparatus includes: a memory; and a processor coupled to the memory. The processor executes a process including: calculating an allocation pattern not requiring cancellation of a connection request from among a plurality of allocation candidates, when the connection request transmitted/received between nodes on a network is to be allocated to a slot that constructs a link on the network; determining a change procedure of the connection request in order to change an allocation pattern provided before the network is re-optimized to the allocation pattern calculated at the calculating; and outputting the allocation pattern calculated at the calculating as an allocation pattern after the network is re-optimized, along with the change procedure determined at the determining.

Network design apparatus and network design method

A network design method that determines a TDM transmission line for accommodating a given demand includes: extracting an available demand from among a plurality of provided demands; calculating a total bandwidth of the extracted available demand; sequentially selecting the plurality of demands; generating candidates for a combination of TDM transmission lines that accommodate the selected demand; and determining a combination of TDM transmission lines that accommodates the selected demand from among the candidates for the combination of TDM transmission lines. The generating process includes: extracting a TDM transmission line with a band utilization efficiency higher than a specified threshold from among TDM transmission lines including the selected demand as an available demand; and generating candidates for a combination of TDM transmission lines that accommodate the selected demand using the extracted TDM transmission line.

Method and apparatus for designing network

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.

Demand accommodation designing system and method

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.

Based on the demand information etc., an accommodation designing problem and an assignment problem are solved in a conventional method to design a network. It is confirmed whether or not a restriction on the number of wavelengths for each link is observed. When there are links exceeding the restriction of the number of wavelengths, the number of available wavelengths is subtracted from the first link having the largest number of excess wavelengths and the second link farthest from the first link in the links, and the result is set as a wavelength number limited value, thereby performing a network designing process again.

Network design apparatus

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.

Dispersion compensation design method and dispersion compensation design system

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.

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.

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Kawasaki, Japan

Tomohiro Hashiguchi