Patent application number | Description | Published |
20080240738 | OPTICAL RECEIVER, OPTICAL COMMUNICATION DEVICE, AND OPTICAL SIGNAL RECEIVING METHOD - An optical receiver including a demodulator to convert an in-phase signal of a received differential phase modulated optical signal into a first electrical signal, and to convert a quadrature signal of the received differential phase modulated optical signal into a second electrical signal; a decision member deciding logic states of the first and second electrical signals; a logic controller using the decision result of the decision member to control logic states of the first and second electrical signals; and a memory storing information relating to the decision result. The logic controller controls the logic state using the information relating to the decision result stored in the memory. | 10-02-2008 |
20090003198 | Method for accommodating signal paths to ring network - According an aspect of the embodiment, there is provided a method for accommodating signal paths to a ring network. A demand chain is defined as a series of traffic demands in which each traffic demand shares one of the pair of terminal nodes pointed thereby with at least one adjacent traffic demand and the number of pairs of terminal nodes pointed by traffic demands in the series of traffic demands is maximized. Each traffic demand of the demand chain is corresponded to a demand accommodating route which is defined as a route between the pair of terminal nodes on the ring network pointed by the each traffic demand and arranged in a predetermined rotation direction on the ring network. Then, signal paths required by traffic demands each pointing a pair of terminal nodes both included in the demand accommodating route chain are accommodated to the demand accommodating route chain. | 01-01-2009 |
20090087194 | Optical transmission system and optical transmission method - An optical transmission system, where in an optical transmitter a detection bit having a specific pattern set according to the number of bits to be transmitted within one symbol time, is imparted with respect to a transmission signal in which transmission information has been encoded according to a preset format, and an optical signal generated by modulating light according to the transmission signal is transmitted to a transmission line. In an optical receiver, logic inversion or bit swap of received data is detected and compensated by using the detection bit included in the received signal, a decoding process of the compensated received signal is executed. As a result, when an optical signal capable of transmitting multi-bit information within one symbol time is transferred, it is possible to realize excellent transmission characteristics, by reliably compensating an error in received data caused by the modulation format or the multiplex system of the optical signal. | 04-02-2009 |
20090185805 | NETWORK DESIGN APPARATUS, NETWORK DESIGN METHOD, AND COMPUTER PRODUCT - A network design apparatus designs arrangement of various types of optical transmission devices in stations within a linear section in a network. An acquisition unit acquires information concerning the type of optical transmission device to be provided in the stations, and information concerning cost and transmission degradation for the optical transmission devices. The designing unit designs, based on the information acquired by the acquisition unit, an arrangement for which transmission degradation between stations respectively including an optical transmission device applicable as an optical regenerative repeater, is less than or equal to a threshold, and also has the least cost. An output unit outputs information concerning the arrangement designed by the design unit. | 07-23-2009 |
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 |
20100003036 | Communication apparatus and signal reception method - A communication apparatus in accordance with an embodiment comprises a reception unit configured to demodulate a received signal to output a first demodulated signal in dependence on a reception condition. The communication apparatus further comprises a pattern detection unit configured to detect a characteristic pattern in the first demodulated signal to output a pattern detection signal, and a pitch detection unit configured to detect a pitch of the characteristic pattern based on the pattern detection signal to output a first signal detection signal indicating that the first demodulated signal is one of an in-phase signal and a quadrature signal, or an inverted version of the one of the in-phase signal and the quadrature signal. | 01-07-2010 |
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 |
20100067547 | Frame generating device - A frame generating device includes an inserting portion and an accommodating portion. The inserting portion inserts a first fixed stuff byte and a second fixed stuff byte into a payload area of an OTU frame, the first fixed stuff byte being of (8+10n (“n” is zero or a given positive integer))×4 rows, the second fixed stuff byte being of a given byte×4 rows, the given byte being equal to zero or more and being equal to (24−10n) or more. The accommodating portion accommodates Ethernet signal in the payload area other than the first fixed stuff byte and the second fixed stuff byte. | 03-18-2010 |
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 |
20100135676 | Optical signal reception device and method of controlling optical signal reception - An optical signal reception device that receives and demodulates an optical signal modulated by DQPSK and performs logical inversion and other controls to transit to the object reception state. The signal reception device includes a front end including a delay interferometer and an opto-electric conversion element that receive the DQPSK optical signal and convert it into an in-phase signal and a quadrature-phase signal, a clock regenerator that regenerates a clock signal based on the in-phase signal and the quadrature-phase signal, a multiplexer that multiplexes the in-phase signal and the quadrature-phase signal, a reception frame processing unit that detects frame synchronization based on the signal multiplexed by the multiplexer and de-maps the received frames, and a controller that, based on out-of-frame-synchronization information (LOF/OOF) from the reception frame processing unit, performs logical inversion control in the clock regenerator, multiplexing timing control in the multiplexer, and controls the delay interferometer in the front end so as to transit to the object reception state. | 06-03-2010 |
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 |
20100226648 | FRAME GENERATING APPARATUS AND FRAME GENERATING METHOD - A frame generating apparatus accommodating a client signal in an optical data transfer unit frame with a higher bit rate than the client signal includes a deserializer, a plurality of generic mapping procedure circuits, and a serializer. The deserializer deserializes the client signal into parallel signals, the number of parallel signals corresponding to the number of tributary slots used in the optical data transfer unit frame. The plurality of generic mapping procedure circuits inserts data and stuff into a frame accommodating portion of the optical data transfer unit frame based on a difference in the bit rate between the client signal and the optical data transfer unit frame. The serializer serializes the parallel signals output from the plurality of generic mapping procedure circuits. | 09-09-2010 |
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 |
20110103222 | SIGNAL TRANSMISSION METHOD AND TRANSMISSION DEVICE - A signal transmission method includes causing each of a plurality of nodes to transfer, using the actually used line, a second signal in a second layer, in which one or a plurality of first signals in a first layer are contained, to a node adjacent in the first or the second direction when each of the plurality of nodes transmits or receives the first signal, when no failure occurs in a transmission path in a network, and causing a first node, located at an end of a failure point, to switch a transmission direction of the second signal and to send out the second signal to the backup line, and causing a second node, which is a transmission source or a reception destination of the first signal, to select one of the first and second directions, when a failure occurs in the transmission path in the network. | 05-05-2011 |
20110135304 | TRANSMISSION APPARATUS AND SIGNAL MAPPING METHOD - A transmission apparatus exercises insertion control for inserting a client signal and a stuff byte into a payload area in a frame into which the client signal is to be mapped, and sends the frame after the insertion control. In addition, the transmission apparatus inserts the client signal or the stuff byte in columns of the frame into the payload area except a leading column. | 06-09-2011 |
20110229133 | TRANSMISSION APPARATUS AND SIGNAL TRANSMISSION METHOD - A transmission apparatus stores frame data of a first frame in a second frame having a bit rate different from that of the first frame through regulation of the amount of stuffs to be stored in the second frame. The transmission apparatus includes: a storage unit storing the first-frame frame data; a first control unit controlling a timing of writing the first-frame frame data in the storage unit based on first stuff information indicating the amount of stuffs contained in the first frame; an arithmetic and logic unit obtaining second stuff information indicating the amount of stuffs to be contained in the second frame based on a bit rate ratio between the first frame and the second frame; and a second control unit controlling a timing of reading out the first-frame frame data stored in the storage unit based on the second stuff information. | 09-22-2011 |
20110274430 | Optical transmission system - An optical transmission system, where in an optical transmitter a detection bit having a specific pattern set according to the number of bits to be transmitted within one symbol time, is imparted with respect to a transmission signal in which transmission information has been encoded according to a preset format, and an optical signal generated by modulating light according to the transmission signal is transmitted to a transmission line. In an optical receiver, logic inversion or bit swap of received data is detected and compensated by using the detection bit included in the received signal, a decoding process of the compensated received signal is executed. As a result, when an optical signal capable of transmitting multi-bit information within one symbol time is transferred, it is possible to realize excellent transmission characteristics, by reliably compensating an error in received data caused by the modulation format or the multiplex system of the optical signal. | 11-10-2011 |
20120170928 | OPTICAL TRANSMITTER, OPTICAL TRANSMISSION METHOD, AND WAVELENGTH-SELECTIVE VARIABLE DELAYER - An optical transmitter is provided for transmitting a wavelength multiplexed signal comprising an intensity modulation optical signal and a phase modulation optical signal through a transmission line. The optical transmitter includes a bit time difference given signal generator for generating at least two optical signals having a bit time difference therebetween, from the wavelength multiplexed signal. The optical transmitter further includes a wavelength multiplexed signal output unit to which at least two optical signals are input from the bit time difference given signal generator, and which generates and outputs a wavelength multiplexed signal in which the bit time difference was given between the phase modulation optical signal and the phase modulation optical signal. | 07-05-2012 |
20120230350 | SIGNAL DEMULTIPLEXER, SIGNAL MULTIPLEXER, AND SIGNAL MULTIPLEXER/DEMULTIPLEXER - A signal demultiplexer includes a conversion unit that converts a format of a high speed signal transfer frame output from a terminating unit into a format of a converted frame; a parallelization unit that parallelizes the converted frame and outputs a predetermined number of data columns; and a separating unit that separates plural low speed signal transfer frames from the predetermined number of the data columns. The conversion unit converts the format of the high speed signal transfer frame into the format of the converted frame by delaying a signal storing area using first and second overhead areas, to include an “i” th tributary slot among the predetermined number of the tributary slots assigned to the signal storing area into an arbitrary “i” th data column among the predetermined number of the data columns, and to align front positions of the predetermined number of the data columns. | 09-13-2012 |
20120237201 | TRANSMISSION APPARATUS AND NETWORK PROTECTION METHOD - A transmission apparatus includes a processor configured to recognize a number of working failures and a number of protection failures on a network for transmission of wavelength-multiplexed signal light, the number of working failures being the number of failures in signal light in wavelengths at a working entity and the number of protection failures being the number of failures in signal light in wavelengths at a protection entity, configured to perform path switching for each group of signal light in wavelengths that are different from each other and configured to select, when multiple failures occur, restoration processing, on a basis of the number of working failures and the number of protection failures. | 09-20-2012 |
20120251127 | FRAME MAPPING APPARATUS AND FRAME MAPPING METHOD - An apparatus for mapping multiple lower-speed signal transmission frames to a higher-speed signal transmission frame. The apparatus includes buffers configured to buffer the lower-speed signal transmission frames, determination units configured to determine frequency justification information for the lower-speed signal transmission frames, a barrel shifter configured to receive signals output from the buffers, and a controller configured to control the barrel shifter to map the lower-speed signal transmission frames to the higher-speed signal transmission frame based on external settings for the respective lower-speed signal transmission frames and the frequency justification information determined by the determination units. When the minimum unit of the lower-speed signal transmission frames is a channel, the number of the buffers and the number of the determination units correspond to the maximum number of channels that can be multiplexed in the higher-speed signal transmission frame. | 10-04-2012 |
20120281985 | TRANSMITTING APPARATUS AND SIGNAL TRANSMITTING METHOD - A transmitting apparatus includes a frame dividing circuit that maps frame data of each of a plurality of frames whose period is different from each other into one or a plurality of internal frames having a fixed frame period and a fixed transmission rate, based on a predetermined internal clock; a cross-connect circuit that cross-connects the frame data of each in a time division multiplexing system based on the internal clock in units of the internal frames; and a frame combining circuit that demaps, into any of the plurality of frames, or multiplexes, data of one or a plurality of internal frames cross-connected by the cross-connect circuit. | 11-08-2012 |
20130010591 | TRANSMISSION APPARATUS, FAILURE RECOVERY METHOD, AND NETWORK SYSTEM - An object is to simplify a process performed due to a failure recovery. To realize this object, the transmission apparatus includes a determining unit that determines, when a transmission apparatus receives a frame from each ring in a network including multiple rings in which a part of each ring is shared, whether failure information indicating that a failure has occurred in one of the rings is contained in one of the received frames. The transmission apparatus also includes a mapping unit that maps a frame that is determined by the determining unit to contain the failure information, onto a shared frame that is a frame used in a shared portion in the multiple rings. Accordingly, the process performed due to a failure recovery can be simplified. | 01-10-2013 |
20130028592 | APPARATUS AND METHOD FOR SWITCHING PATHS IN A WAVELENGTH-MULTIPLEXING NETWORK - An apparatus switches paths in a wavelength-multiplexing network in which a first number of wavelengths each used for a path to transmit an optical signal are multiplexed into an optical fiber. The apparatus includes an entire switching unit and a second number of individual switching units where the second number is smaller than the first number. The entire switching unit is configured to perform a path-switching process for switching a path, simultaneously on all the first number of wavelengths when failures have occurred for all the first number of wavelengths. The second number of individual switching units are each configured to perform the path-switching process individually on one of a third number of wavelengths included in the first number of wavelengths when at least one failure has occurred for the third number of wavelengths where the third numbers is smaller than the first number. | 01-31-2013 |
20130028613 | TRANSMISSION APPARATUS, RECEPTION APPARATUS, TRANSMISSION METHOD, AND RECEPTION METHOD - A transmission apparatus includes a generation unit configured to generate a first data unit including a second data unit, and an addition unit configured to add fault data indicating a fault state of the second data unit to a data portion different from a data portion in which the second data unit is positioned within the first data unit. | 01-31-2013 |
20130058643 | DATA AMOUNT DERIVATION APPARATUS - A data amount derivation apparatus includes: a first calculator configured to derive, for one series of parallelized mapping signals, amount of data in each frame period for a frame into which the parallelized mapping signals are mapped; and a second calculator configured to sum up amounts of data in N frame periods, where N is an integer, and to derive the resulting summation value as the amount of data to be mapped into the frame, each of the amounts of data in each of the frame periods being derived by the first calculator. | 03-07-2013 |
20130058655 | TRANSMISSION APPARATUS FOR OPTICAL TRANSPORT NETWORK, AND STAFF CONTROL METHOD THEREFOR - A transmission apparatus for an optical transport network includes maps client data to a payload of an optical transport unit in order to obtain a higher layer frame generated based on a clock on the optical transport network side, and sends the higher layer frame to the optical transport network. A Cn value indicating an amount of the client data to be mapped to the payload of the optical transport unit is computed based on a counted value, counted using a clock of the client data, of a time period corresponding to the payload of the optical transport unit in the higher layer frame generated using a clock of the optical transport network. | 03-07-2013 |
20130136008 | METHOD OF ACCOMMODATING SIGNALS, FRAME GENERATION APPARATUS, FRAME RECEPTION APPARATUS, AND TRANSMISSION SYSTEM - For a frame comprising a payload region in which a client signal is to be accommodated, and an overhead region accommodation location information indicating a location where the client signal is to be accommodated, the frame being able to be processed as an m (m is an integer equal to or greater than 2)-byte cycle multiframe, the location information for the frame is defined as an m×n (n is an integer equal to or greater than 2)-byte cycle multiframe; using the location information defined as the multiframe, the location where the client signal is to be accommodated in the payload region is defined; and the client signal is accommodated in the payload region, based on the defined location where the client signal is to be accommodated. | 05-30-2013 |
20130216227 | RING NETWORK SETUP METHOD - A network setup method used in a ring network including a plurality of transmission equipments. The method includes: transmitting a frame in the ring network; causing each of the transmission equipments to write an identifier to the frame according to a specified rule; determining whether or not a plurality of identifiers written to the frame by the plurality of transmission equipments satisfy a specified condition; and causing each of the transmission equipments to obtain a corresponding identifier according to the specified rule from among the plurality of identifiers, when the plurality of identifiers satisfy the specified condition. | 08-22-2013 |
20130222021 | TRANSMITTING APPARATUS AND TRANSMITTING METHOD - A transmitting apparatus includes a first circuit to which a base clock and a first clock condition are input, the first circuit outputting a first enable signal based on the base clock and the first clock condition; a second circuit to which the base clock and a second clock condition are input, the second circuit outputting a second enable signal based on the base clock and the second clock condition; a first frame processing circuit receiving a first frame input signal and the first enable signal to output a first frame output signal in synchronization with the first enable signal; and a second frame processing circuit receiving a second frame input signal and the second enable signal to output a second frame output signal in synchronization with the second enable signal. | 08-29-2013 |
20130294229 | FAILURE PROTECTION METHOD AND NODE APPARATUS - A failure protection method of a network connecting between nodes by multiple working paths and a protection path is disclosed. An allocation bandwidth is determined to allocate to a detected path where a failure is detected in multiple paths being set to the multiple working paths, depending on the detected path. The detected path is switched from one of the multiple working paths to the protection path. Data to be transmitted by the detected path is transmitted by using the allocation bandwidth determined within an entire bandwidth of the protection path. | 11-07-2013 |
20140178073 | OPTICAL TRANSMISSION DEVICE INCLUDING A BIT RATE ADJUSTMENT FUNCTION - An optical transmission device, which transmits a first frame containing second frames, includes newly adding and allocating, when a bit rate of a specific second frame among the second frames is to be changed, a time slot corresponding to an increase in the bit rate of the specific second frame to time slots previously set for the second frames in time slots of the first frame; and inputting a dummy signal as data to the newly-added time slot while performing such a setting that both of: a data writing speed and a data reading speed; and a delay time between writing and reading of the data for the newly-added time slot are in agreement with both of: a data writing speed and a data reading speed; and a delay time between writing and reading of the data for each time slot of the previously-set time slots. | 06-26-2014 |
20140321849 | APPARATUS FOR CONTROLLING A TRANSMISSION PATH - An apparatus includes a switch unit configured to switch signal paths between a plurality of input ports and a plurality of output ports. The apparatus controls the signal paths according to the connection setting information stored in the apparatus. The connection setting information includes first and second connection information. The first connection setting information specifies a first output port to which a signal input via an input port is to be output, in association with identification information identifying the signal, and the second connection setting information specifies a second output port to which the signal is to be alternatively output. The apparatus controls setting of a signal path of the switch unit, based on the second connection setting information in a case where another signal path has been already allocated to the first output port specified by the first connection setting information. | 10-30-2014 |