Patent application number | Description | Published |
20090220241 | CHROMATIC DISPERSION COMPENSATION DESIGNING METHOD IN OPTICAL NETWORK AND A SYSTEM THEREOF - 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. | 09-03-2009 |
20090274459 | OPTICAL NODE APPARATUS - The present invention is directed to an optical node apparatus in which the number of light elements that propagates reference light is reduced, which includes pa input-side wavelength mux/demux elements, a switch module, pb output-side wavelength mux/demux elements, and a reference light source. Each of the input-side wavelength mux/demux element include at least two first port and at least two second port. One of the first ports included in each input-side wavelength mux/demux element is coupled to an input transmission path. The other of the first ports coupled to the reference light source, and each of the second ports is coupled to an input end of the switch module. | 11-05-2009 |
20090290873 | Optical communication system - 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. | 11-26-2009 |
20100061722 | NETWORK DESIGN APPARATUS AND NETWORK DESIGN METHOD - 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. | 03-11-2010 |
20100080556 | CHROMATIC DISPERSION COMPENSATION DESIGN SYSTEM AND CHROMATIC DISPERSION COMPENSATION DESIGN METHOD - 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. | 04-01-2010 |
20100098434 | METHOD FOR DETERMINING VALUE OF CHROMATIC DISPERSION COMPENSATION - 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. | 04-22-2010 |
20100166421 | APPARATUS AND METHOD FOR DESIGNING NETWORK - In a network design apparatus, a full channel evaluator determines whether all wavelength channels for main signals can deliver the main signals of an existing optical network. When it is found that one or more wavelength channels cannot deliver main signals, a chromatic dispersion evaluator determines whether there are a specified number of wavelength channels that satisfy a specified chromatic dispersion condition. An optical signal-to-noise ratio (SNR) evaluator extracts a specified number of wavelength channels out of those satisfying the chromatic dispersion condition in descending order of optical SNRs thereof, and determines whether the extracted wavelength channels satisfy a specified optical SNR condition. | 07-01-2010 |
20100215377 | OPTICAL NETWORK DESIGN APPARATUS AND DISPERSION COMPENSATION DESIGN METHOD - 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. | 08-26-2010 |
20110008044 | Optical-network design apparatus - 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. | 01-13-2011 |
20110019554 | NETWORK DESIGN DEVICE AND NETWORK DESIGN METHOD - 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. | 01-27-2011 |
20110038254 | APPARATUS AND METHOD FOR FINDING A PAIR OF DISJOINT PATHS IN A COMMUNICATION NETWORK - 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. | 02-17-2011 |
20110052193 | NETWORK DESIGN APPARATUS, METHOD, AND COMPUTER PRODUCT - 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. | 03-03-2011 |
20110206371 | APPARATUS FOR SUPPORTING DESIGNING OF OPTICAL NETWORK, PROCESS FOR DESIGNING OPTICAL NETWORK, AND COMPUTER-READABLE, NON-TRANSITORY MEDIUM STORING NETWORK DESIGN PROGRAM - 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. | 08-25-2011 |
20110229134 | OPTICAL NETWORK DESIGNING DEVICE, METHOD, AND PROGRAM - 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. | 09-22-2011 |
20120079116 | APPARATUS AND METHOD FOR ALLOCATING DEVICES TO A COMMUNICATION ROUTE - 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. | 03-29-2012 |
20120237214 | 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. | 09-20-2012 |
20130003730 | PATH SEARCH PROGRAM, PATH SEARCH APPARATUS AND PATH SEARCH METHOD - 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. | 01-03-2013 |
20130054834 | ROUTE SEARCH DEVICE, ROUTE SEARCH METHOD, AND ROUTE SEARCH PROGRAM - 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. | 02-28-2013 |
20130101286 | DEMAND ACCOMMODATION DESIGNING SYSTEM AND METHOD - 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. | 04-25-2013 |
20130302026 | APPARATUS AND METHOD FOR SEARCHING A COMMUNICATION NETWORK INCLUDING AN ASYMMETRY NODE FOR A ROUTE - 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. | 11-14-2013 |
20130311150 | RECORDING MEDIUM, ACCOMMODATION DESIGN DEVICE, AND ACCOMMODATION DESIGN 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. | 11-21-2013 |
20140099112 | NETWORK DESIGN APPARATUS, NETWORK DESIGN METHOD, AND STORAGE MEDIUM STORING NETWORK DESIGN PROGRAM - 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. | 04-10-2014 |
20140169782 | NETWORK DESIGN APPARATUS AND NETWORK DESIGN METHOD - 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. | 06-19-2014 |
20140286640 | METHOD AND APPARATUS FOR DESIGNING NETWORK - 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. | 09-25-2014 |
20140344433 | NETWORK DESIGN APPARATUS AND NETWORK DESIGN METHOD - 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. | 11-20-2014 |
20150023666 | NETWORK DESIGNING APPARATUS, NETWORK DESIGNING METHOD, AND NETWORK DESIGNING PROGRAM - A network designing apparatus which includes a first processing unit configured to select one or more paths formed among nodes in a network according to demands of bandwidths, determine a plurality of working communication routes and a plurality of protecting communication routes that connect the nodes to each other, respectively and estimate bandwidths and the number of communication lines required in one or more selected paths, respectively; and a second processing unit configured to allocate a predetermined number of logical channels to the working communication routes and the protecting communication routes based on the demanded bandwidths, the predetermined number of logical channels being corresponding to a number of logical channels that each of the communication lines has. The first processing unit is configured to permit the one or more paths to be shared among the plurality of protecting communication routes to determine the protecting communication routes and estimate bandwidths shared among communication routes sharing the paths. | 01-22-2015 |
20150050016 | APPARATUS AND METHOD FOR DESIGNING A NETWORK TRANSMITTING WAVELENGTH MULTIPLEXED OPTICAL SIGNALS - 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. | 02-19-2015 |
20150052233 | NETWORK DESIGN APPARATUS, NETWORK DESIGN METHOD, AND RECORDING MEDIUM - A network design apparatus includes a first processing unit configured to determine a communication route that connects predetermined nodes by selecting one or more paths provided between the nodes in a network, and to perform an estimation of communication lines opened in each of the selected one or more paths; a second processing unit configured to perform an estimation of communication apparatuses constituting the communication line and a housing that accommodates the communication apparatuses, for each node in the network, based on an estimation result of the first processing unit; and a third processing unit configured to determine whether there is a possibility of reduction in the number of the housings due to a change in the communication line, for each node in the network, based on respective estimation results of the first processing unit and the second processing unit. | 02-19-2015 |
20150071294 | APPARATUS AND METHOD FOR DESIGNING A COMMUNICATION NETWORK PREVENTING OCCURRENCE OF MULTIPLE FAILURES - An apparatus generates plural communication-route candidates corresponding to a requested communication channel by combining first transmission-paths providing connections between particular nodes in a network and second transmission-paths providing connections between three or more nodes in the network, where the first transmission paths are accommodated in plural communication cables together with the second transmission paths. The apparatus holds a table indicating first and second association relationships, where the first association relationship associates the first transmission paths with communication cables that accommodate the first transmission paths and are provided at opposite ends of each of the first transmission-paths, and the second association relationship associates the second transmission paths with communication cables accommodating the second transmission paths. The apparatus determines, by referring to the table, from among the plural communication-route candidates, a communication-route candidate that uses a same communication cable multiple times, and excludes the determined communication-route candidate from the plural communication-route candidates. | 03-12-2015 |
20150071635 | APPARATUS AND METHOD FOR EFFECTIVE DESIGN OF A COMMUNICATION NETWORK ENABLING LARGE-CAPACITY TRANSMISSION - An apparatus designs a communication route for each of requested channels by selecting, with higher priority, first transmission-paths providing connections between particular nodes in a network in which a wavelength-multiplexed optical signal is transmitted than second transmission-paths providing connections between three or more nodes in the network, and assigns, for each channel, a wavelength included in the wavelength-multiplexed optical signal. Between the particular nodes, when the number of wavelengths assigned to channels passing through the first transmission-paths is greater than the number of wavelengths assigned to channels passing through the second transmission-paths, the apparatus modifies the designed communication routes and the assigned wavelengths so that, via any of the particular nodes, one of two channels having the same wavelength is routed from the first transmission-paths to the second transmission-paths and the other one of the two channels is routed from the second transmission-paths to the first transmission-paths. | 03-12-2015 |