| Entries |
| Document | Title | Date |
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| 20080205886 | Method and Device for In-Band Optical Performance Monitoring - A method and device for determining in-band noise of an optical signal. The optical signal is split to produce two optical signal components, of distinct polarisation, such that the respective noise component in each signal component is uncorrelated. The optical signal components are converted to the electrical domain to produce electrical signal components. The signal component powers are equalised either in the optical domain or the electrical domain. The equalised electrical signal components are then subtracted together to cancel the correlated portions of the signal components (e.g. the data signal), such that only uncorrelated signal components (e.g. noise) are output for measurement. | 08-28-2008 |
| 20080273873 | Optical Path Feasibility in an Optical Communication Network - A method of assessing the feasibility of a composite optical path in an optical communications network in which the composite path is composed of two optical paths k | 11-06-2008 |
| 20080298801 | ELECTRONIC DISPERSION COMPENSATION SYSTEMS AND METHODS - A test has been developed that is known as the transmitter waveform dispersion penalty (TWDP) test. The TWDP test has been used to test and certify various optical data transmission devices. Similar tests are being developed to test optical receivers such as a difference waveform distortion penalty (dWDP). A test pattern used to generate the transmitted sequence by the device under test is a PRBS9. The PRBS9 test pattern begins with a run of nine ones and has a length of 511 bits. According to the teachings herein, a test pattern of less than 511 bits is generated to perform the TWDP and dWDP tests. The test pattern may include a sequence of bits specifically designed to provide reliable test penalty calculation without the costly and time consuming aspects of the conventional TWDP and dWDP tests using the PRBS9 pattern. | 12-04-2008 |
| 20090052891 | Method and Apparatus for Reducing Error Rate During Data Transmission in an Optical Communications Network - An apparatus and a method of enhancing data integrity for data transmission over an optical network are disclosed. Upon detecting a low performance condition associated to the optical communications network, an error correcting code (“ECC”) device is activated. The ECC device inserts the ECC to a data stream to form an ECC data stream. Once the ECC data stream reaches to the destination, the ECC device corrects any errors incurred during the transmission, and removes the ECC from the ECC data stream. It should be noted that the ECC device can also be activated by a request from a network operator. | 02-26-2009 |
| 20090080882 | Method And Apparatus For In-Band OSNR Monitoring - An optical signal-to-noise ratio monitor includes a demodulator comprising an input that receives at least a portion of a phase modulated optical signal. The monitor also includes a delay interferometer with a periodic phase control that sweeps a differential delay of one arm of the interferometer through a plurality of differential optical phase shifts. The demodulator converts phase modulated optical signals to intensity modulated optical signals. A tunable optical filter continuously scans a transmission wavelength over a desired wavelength range in a time that allows more than one wavelength to be transmitted through an output of the tunable filter for each of the plurality of differential optical phase shifts. An optical detector detects the filtered optical signal and generates a corresponding electrical demodulation signal at an output. A processor determines an optical signal-to-noise ratio for the more than one wavelength of the optical signal. | 03-26-2009 |
| 20090142052 | Monitoring of Optical Signals - An apparatus and method for monitoring of optical signals | 06-04-2009 |
| 20090148158 | OPTICAL SIGNAL QUALITY MONITORING APPARATUS - The present invention relates to the quality monitoring of optical signals, which have different symbol rates and generated by different modulation schemes, used for example in a wavelength division multiplexing network. The apparatus according to the invention includes an optical splitter for outputting the input optical signal to a first optical route and a second optical route, an optical coupler for coupling a optical signal from the first optical route with a optical signal from the second optical route, a delay unit provided on the first optical route, and a phase shift unit provided on the first optical route or the second optical route. | 06-11-2009 |
| 20090190923 | Electronic apparatus - A system including a device equipped with a reception section, a reception condition detection section and a control section. A partner device emits laser light and modulates the laser light in accordance with transfer subject information. Relative positions of the partner device and the device are adjusted to a communication-possible position, at which the laser light from the partner device is incident in a light reception region of the device. In this state, the reception section receives the transmission subject information from the partner device by detecting the incident laser light and demodulating the transmission subject information therefrom. The reception condition detection section detects a deterioration in a reception condition. If a deterioration in the reception condition is detected, the control section produces a warning or stops emissions of laser light from the partner device. | 07-30-2009 |
| 20090196602 | Adjustable Bit Rate Optical Transmission Using Programmable Signal Modulation - Techniques, apparatus and systems to provide adjustable bit rate optical transmission using programmable signal modulation in optical communication systems. | 08-06-2009 |
| 20090279886 | Burst-mode data recovery for multi-gigabit passive optical networks - In a TDMA optical network, a clock data recovery module uses signal oversampling and preamble correlation together with enhanced performance modules to extract additional data from the upstream transmission signal. Information including duty cycle, ONT power estimation, signal noise and jitter can be extracted from the upstream signal using digital logic and used to tune network components and/or alleviate network conditions. | 11-12-2009 |
| 20090304380 | Quality of service in an optical network - A method and apparatus for implementing optical network quality using bit error rate and chromatic dispersion. According to one embodiment of the invention, a method includes the provision of quality of service in a wavelength division multiplexing optical network that supports a plurality of bit rates. As part of this method, the cumulative noise and cumulative chromatic dispersion for each available path as a whole is determined, where an available path is a series of two or more nodes each connected by an optical link on which a set of wavelengths is available for establishing a lightpath. In addition, different grades of path quality are distinguished based on bit error rate (BER), where BER is based on cumulative noise and bit rate. Furthermore, a minimum path quality is required based on chromatic dispersion decibel penalty, where chromatic dispersion decibel penalty is based on cumulative chromatic dispersion and bit rate. | 12-10-2009 |
| 20090317077 | METHOD FOR DETERMINING THE OPTICAL SIGNAL-TO-NOISE RATIO AND RECEIVER DEVICE FOR AN OPTICAL TRANSMISSION SYSTEM - An optical noise signal is added to an optical data signal on the receiver side, and a signal quality of the data signal is determined. The magnitude of the added noise signal is varied, and a function of the signal quality of the data signal is determined in dependence on the added noise signal. Subsequently, a first straight line is approximated to the previously determined function for smaller values of the added noise signal, and a second straight line for larger values of the added noise signal. The optical signal-to-noise ratio is read from the intersecting point of the first straight line with the second straight line. Thus, the ASE present is derived from the controlled addition of additional ASEs, and the optical signal-to-noise ratio is determined. The process is particularly suited for DWDM systems because it works even with very narrow channel separations, or with narrowband optical filtration along the separation. | 12-24-2009 |
| 20100008663 | METHOD AND ARRANGEMENTS FOR DETERMINING THE OPTICAL SIGNAL-TO-NOISE RATIO FOR AN OPTICAL TRANSMISSION SYSTEM - According to the invention, various noise currents are added to the electrical data signal after the opto-electric conversion of an optical data signal, and an optimum decision threshold for the electrical data signal equipped with this noise current is determined for each noise current. Values for a median signal current and for a median noise current of the amplified spontaneous emission are subsequently determined from the value pairs of the optimum decision threshold and the added noise current in accordance with a computation rule that is based on a noise model, and the optimum signal-to-noise ratio is calculated from their quotient. The method may also be advantageously implemented by means of simple expansions of common receiver devices. | 01-14-2010 |
| 20100040364 | Method and apparatus for reducing cost of an optical amplification in a network - Signals propagating in wavelength division multiplexing (WDM) optical networks suffer from loss, which decreases optical signal-to-noise ratios (OSNRs) and degrades a quality of received transmissions. Present methods of boosting OSNRs involve regeneration using transponders, which scale in complexity with the number of WDM channels. Optical amplifiers may boost signal strength, but amplified spontaneous emission (ASE) noise often reduces OSNR despite increases in signal strength, although changing the amplifier operating settings may reduce emitted ASE noise power. A method or corresponding apparatus in an example embodiment of the present invention provides a planning tool for deploying optical amplifiers in an optical network in a manner that reduces the need for optical regeneration, reducing cost and complexity of the deployed network. In one embodiment, the disclosed planning tool may substitute models of high-gain amplifiers operating at low settings for models of low-gain amplifiers operating at high settings. | 02-18-2010 |
| 20100040365 | Method and apparatus for planning network configuration in an optical network - Optical regenerators and amplifiers are expensive to implement and maintain. A method or corresponding apparatus in an example embodiment of the present invention relates to an optical planning tool that plans an optical network configuration by determining a plurality of costs for maintaining signal strength in corresponding network configurations including (i) a configuration of regenerators, (ii) a configuration of pre- or post-amplifiers, and (iii) a configuration of pre- and post-amplifiers in candidate locations and regenerator modules. The candidate locations for placing pre- or post-amplifiers are determined based on loss in each span, expected traffic patterns, and proposed regeneration locations along paths of expected traffic. The regeneration modules are located in locations determined based on the candidate locations. The example embodiment selects a configuration from among the network configurations as a function of the plurality of costs, helping reduce the cost of network deployment. | 02-18-2010 |
| 20100046942 | PHASE ESTIMATION FOR COHERENT OPTICAL DETECTION - The present invention is a method and apparatus to make an estimate of the phase of a signal relative to the local oscillator in an optical coherent detection subsystem that employs a digital signal processor having a parallel architecture. The phase estimation method comprises operations that do not use feedback of recent results. The method includes a cycle count function so that the phase estimate leads to few cycle slips. The phase estimate of the present invention is approximately the same as the optimal phase estimate. | 02-25-2010 |
| 20100054735 | OPTICAL OFDMA NETWORK WITH DYNAMIC SUB-CARRIER ALLOCATION - A system and method for dynamically allocating sub-carriers between the nodes of an optical OFDMA ring network or an OFDMA passive optical network. A carrier allocation system assigns sub-carriers according to a utility function based on real-time measurements of arrival data rates and queue length variance. | 03-04-2010 |
| 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 |
| 20100067903 | Interferometric optical signal-to-noise ratio measurement using a calibration factor - Systems and methods are described that measure the OSNR of an optical channel. Embodiments provide OSNR measurement methods that distinguish the intensities of the coherent modulated signal from the incoherent noise intensity occupying the same optical band using a calibration factor ζ. | 03-18-2010 |
| 20100067904 | Calibration factor for interferometric optical signal-to-noise ratio measurement - Systems and methods are described that measure the OSNR of an optical channel. Embodiments provide OSNR measurement methods that distinguish the intensities of the coherent modulated signal from the incoherent noise intensity occupying the same optical band using a calibration factor ζ. | 03-18-2010 |
| 20100129074 | IN-BAND OPTICAL SIGNAL TO NOISE RATIO DETERMINATION METHOD AND SYSTEM - There is provided a method for determining the in-band noise in agile multichannel Dense Wavelength Division Multiplexing (DWDM) optical systems, where the interchannel noise is not representative of the in-band noise in the optical channel. The method relies on the analysis of two observations of the same input optical signal. In the two observations, the linear relationship between the optical signal contribution and the optical noise contribution (i.e. the observed OSNR) is different, which allows the discrimination of the signal and noise contributions in the input optical signal. In a first approach, the two observations are provided by polarization analysis of the input optical signal. In a second, the input optical signal is obtained using two different integration widths. | 05-27-2010 |
| 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 |
| 20100178052 | OPTICAL SIGNAL TO NOISE MONITOR - An optical noise monitoring method and monitor, the monitor comprising an optical transmitter for receiving at least a portion of an optical signal, a device arranged to extract a reflected optical signal comprising a portion of the optical signal back-reflected by stimulated Brillouin scattering in the optical transmitter, and a photodetector for receiving the reflected optical signal. The optical transmitter can scatter the optical signal by stimulated Brillouin scattering. | 07-15-2010 |
| 20100322621 | OSNR MODEL FOR OPTICAL ENGINEERING RULES USED IN A PLANNING TOOL - Increasing data rates in next-generation optical networks requires a change in the type of optical modulation used to encode optical signals carried by the optical networks. Different types of optical modulation incur different optical impairments, which may degrade the fidelity of the optical signals by reducing the optical signal-to-noise ratio (OSNR). A method or corresponding apparatus in an example embodiment of the present invention provides a planning tool for deploying an optical network in a manner based on the optical modulation that reduces the cost and complexity of the deployed network. In one embodiment, the disclosed planning tool may adjust a model of the optical network to be deployed by changing the topology and/or the number and/or type of optical network elements in response to optical impairments for a given optical modulation. | 12-23-2010 |
| 20100322622 | OSNR MONITOR DEVICE AND OSNR MEASUREMENT DEVICE - An OSNR monitor device includes an optical receiver including a delay interferometer which inputs an optical signal in accordance with a given bandwidth and outputs two optical signals and causes the optical signals to interfere with each other and optical detectors which outputs currents in accordance with optical powers of the optical signals output from the interferometer, an optical power monitor configured to obtain the optical powers of the optical signals received by the optical detectors included in the optical receiver, and an OSNR calculator configured to calculate an optical signal-to-noise ratio in accordance with the optical powers obtained from the optical power monitor and the reception bandwidth. | 12-23-2010 |
| 20110033182 | Spectral efficiency estimation in coherent receivers - The present invention relates to optical transmission systems. In particular, the present invention relates to a method and system for estimating the spectral efficiency which may be achievable in an optical transmission network and for adapting the parameters of the transmission network to the achievable spectral efficiency. A method and system for controlling an optical transmission system comprising a first and a second optical transmission channel is described. The first optical transmission channel is affected by the second optical transmission channel. The method comprises the steps of measuring the inverse signal-to-noise ratio of the first channel for a plurality of input power levels used by the first and second channel; determining a contribution of the second channel to the inverse signal-to-noise ratio; and determining the input power to the second channel, such that an overall throughput of the first and second channel is maximized. | 02-10-2011 |
| 20110091206 | IN-BAND OPTICAL NOISE MEASUREMENT USING DIFFERENTIAL POLARIZATION RESPONSE - A method comprises: acquiring, for a number nSOP of varied State-Of-Polarization analysis conditions of the input optical signal, nSOP polarization-analyzed optical spectrum traces; mathematically discriminating said signal contribution from said noise contribution within said optical signal bandwidth using said polarization-analyzed optical spectrum traces, said mathematically discriminating comprising: obtaining a differential polarization response that is related to the optical spectrum of said signal contribution by a constant of proportionality; estimating the constant of proportionality of a differential polarization response to the optical spectrum of said signal contribution; estimating the optical spectrum of said noise contribution from said input optical signal, within said optical signal bandwidth using said constant of proportionality and said differential polarization response; and determining said in-band noise parameter on said input optical signal from the mathematically discriminated noise contribution. | 04-21-2011 |
| 20110110657 | Method for Measuring Signal Quality in WDM Optical Networks - A method and memory medium in a wavelength division multiplexing (WDM) network that communicates multiplexed signals representing a plurality of communication channels to determine received signal quality are disclosed. Generally, the signals format the plurality of communication channels to impart a distinctive noise profile in time or frequency for each channel; and collectively process the channels at a digital signal processing device to measure the signal-to-noise ratio. | 05-12-2011 |
| 20110110658 | SPECTRUM DATA CORRECTION SYSTEM AND SPECTRUM DATA CORRECTION METHOD - An object of the invention is to automatically remove noise out of an input spectrum data while rounding in spectral shape is being suppressed. The spectrum data correction system wherein a noise quantity is detected on the basis of a difference in value between an extremal point of measurement data-blocks making up input spectrum data, and a mean value of measurement data-blocks in the vicinity of the extremal point, and a count of moving-average points of measurement data-blocks subjected to moving average processing is controlled according to the noise quantity, the spectrum data correction system comprises means for using an optical power, detected by a photo-detector of an optical spectrum analyzer, as the measurement data-block, thereby controlling the count of the moving-average points of the measurement data-blocks according to magnitude of a signal level of the measurement data-block. | 05-12-2011 |
| 20110170862 | OPTICAL COMMUNICATIONS IN RECIPROCAL NETWORKS BASED ON WAVELENGTH SWITCHING - Techniques, apparatus and systems to provide packet transmission in reciprocal transmission architecture networks for optical communications. | 07-14-2011 |
| 20110182574 | METHOD AND APPARATUS OPTIMIZING DECISION THRESHOLD LEVEL OF OPTICAL RECEIVER - method and apparatus for optimizing a decision threshold of an optical receiver is used to solve a problem of affecting system stability and reliability. The method comprises: determining a maximum value and a minimum value of an adjustment range of the decision threshold, and determining an adjustment step of the decision threshold ( | 07-28-2011 |
| 20110188851 | OPTICAL NETWORK AND CONTROL METHOD THEREFOR - An attenuation amount corresponding to each wavelength at OADM node is optimized according to a calculation result in a network management system (NMS), so that an optical signal level diagram according to traffic volume variations is set, the level diagram allows each of optical signal quality indexes at terminal nodes for all wavelengths to be maintained at a required threshold value or more, and allows an optical signal quality index of a specific wavelength to be improved. Then, an FEC circuit in an optical receiver corresponding to the specific wavelength is turned OFF or the error correction ability is lowered, whereby power consumption of an overall optical network is efficiently reduced. | 08-04-2011 |
| 20110293268 | METHOD AND APPARATUS FOR PROVIDING COMMUNICATION USING A TERAHERTZ LINK - A method and apparatus for establishing a terahertz link using a multi-element lens array that comprises a liquid lens are disclosed. For example, the method receives detected terahertz signals from one or more detectors, where a liquid lens is deployed with each of the one or more detectors. The method determines, for each of the detected signals, if the detected signal is out of focus, and applies a corrective voltage to each liquid lens that corresponds to a detected terahertz signal that is out of focus, wherein the corrective voltage adjusts a focus of the detected signal. The method measures a signal-to-noise ratio of the detected signals, and establishing a terahertz link via at least one of the detected terahertz signals with a highest signal-to-noise ratio. | 12-01-2011 |
| 20110299849 | METHOD AND APPARATUS FOR SYNTHESIZING AND CORRECTING PHASE DISTORTIONS IN ULTRA-WIDE BANDWIDTH OPTICAL WAVEFORMS - In accordance with various aspects of the disclosure, a method, an apparatus and a system for characterizing and compensating for deterministic phase nonlinearities and distortion inherent in radio frequency and optical components utilized to synthesize a single sideband suppressed carrier optical waveform in the presence of random phase noise generated by an optical carrier source is disclosed. The method comprises mixing a modulated optical signal with a continuous wave optical signal in an optical coupler; optically heterodyning the mixed signal output from the optical coupler in a detector to produce a radio frequency waveform; and analyzing the produced radio frequency waveform in a processor based on a phase history of a preselected continuous wave signal to measure distortion characteristics of the radio frequency modulated optical signal. | 12-08-2011 |
| 20110311222 | OSNR MEASURING DEVICE AND OPTICAL COMMUNICATION SYSTEM - An OSNR measuring device n OSNR measuring device includes an input port to which a signal light is given; a wavelength filter which includes a variable passband, and selectively takes out an optical component corresponding to a signal optical wavelength to be measured from the signal light; a wavelength control circuit which controls the passband of the wavelength filter; a delay interferometer which branches a light output from the wavelength filter and delays one of the branched lights with respect to the other branched light and in which the branched lights are made to interfere with each other; a photodetector which detects a power of a delay interference light output; and an OSNR calculation circuit which calculates, based on a bandwidth of a passband of the wavelength filter and the power of the delay interference light, an optical signal to noise ratio of a signal optical wavelength to be measured. | 12-22-2011 |
| 20120002961 | SYSTEM AND METHOD FOR CHANNEL-ADAPTIVE ERROR-RESILIENT BURST MODE TRANSMISSION - In a passive optical network, an upstream transmission rate from an ONT to an OLT can be optimized by matching a transmission scheme for a channel to the upstream transmission characteristics of the channel. An FEC coding can be made channel dependent so that channels with low error rates can use minimal protection, and therefore minimal overhead, while channels with high input bit error rates can use the level of FEC coding required to produce a desired output bit error rate. | 01-05-2012 |
| 20120008940 | SYSTEM AND METHOD FOR CHANNEL-ADAPTIVE ERROR-RESILIENT TRANSMISSION TO MULTIPLE TRANSCEIVERS - In a passive optical network, a downstream transmission rate from an OLT to multiple ONTs can be optimized by matching a transmission scheme for frames addressed to a channel to the downstream transmission characteristics of the channel. An FEC coding can be made channel dependent so that channels with low error rates can use minimal protection, and therefore minimal overhead, while channels with high input bit error rates can use the level of FEC coding required to produce a desired output bit error rate. | 01-12-2012 |
| 20120020661 | Optical communication device and dispersion compensation method - An optical communication device comprises a variable dispersion compensator, a photoelectric converter, and a processor. The variable dispersion compensator compensates an amount of wavelength dispersion of an optical signal received from an optical transmission line. The photoelectric converter converts the compensated optical signal into an electrical signal. The processor is operative to extract a frequency of the converted electrical signal, and to discriminate bit information of the electrical signal based on the frequency extracted using a decision phase and a decision threshold. The processor is operative to detect bit error information that is information related to an error of the discriminated bit information, and to control the amount of wavelength dispersion based on the detected bit error information. | 01-26-2012 |
| 20120063771 | WDM OPTICAL TRANSMISSION SYSTEM AND CONTROL METHOD THEREOF - A WDM optical transmission system includes a plurality of optical nodes optically coupled by a transmission line, a processor that is operative to calculate an amount of adjustment of a reception level capable of increasing an optical signal-to-noise ratio for each channel of the WDM light reaching the optical node positioned at a receiving end of the unit section based on information on amplification operation of the WDM light in at least one optical-amplification repeating node disposed on the optical transmission line in the unit section, and to adjust a power level corresponding to each channel of the WDM light transmitted on the transmission line from the optical node positioned at a transmission end of the unit section in accordance with a calculation result of the calculation. | 03-15-2012 |
| 20120063772 | OPTICAL SIGNAL TO NOISE RATIO MONITORING TECHNIQUE AND SYSTEM - For determining OSNR | 03-15-2012 |
| 20120093501 | In-Band Optical Noise Measurement Using Differential Polarization Response - A method comprises: acquiring, for a number nSOP of varied State-Of-Polarization analysis conditions of the input optical signal, nSOP polarization-analyzed optical spectrum traces, the distribution of the input optical signal of said SOP analysis conditions being approximately known; mathematically discriminating said signal contribution from said noise contribution within said optical signal bandwidth using said polarization-analyzed optical spectrum traces, said mathematically discriminating comprising: obtaining a differential polarization response that is related to the optical spectrum of said signal contribution by a constant of proportionality; estimating the constant of proportionality of a differential polarization response to the optical spectrum of said signal contribution as a function of said number nSOP; estimating the optical spectrum of said noise contribution from said input optical signal, within said optical signal bandwidth using said constant of proportionality and said differential polarization response; and determining said in-band noise parameter on said input optical signal from the mathematically discriminated noise contribution. | 04-19-2012 |
| 20120099856 | METHOD AND APPARATUS FOR PROVIDING BEAM STEERING OF TERAHERTZ ELECTROMAGNETIC WAVES - A method and apparatus for establishing a terahertz link using a multi-element lens array that comprises a plurality of active beam steering device are disclosed. For example, the method receives detected terahertz signals from one or more detectors, where an active beam steering device is deployed with each of the one or more detectors, and determines, for each of the detected signals, if the detected signal is out of focus from a focus point. The method applies a corrective signal to each active beam steering device that corresponds to a detected terahertz signal that is out of focus from the focus point, wherein the corrective signal causes the detected signal to be redirected, and measures a signal-to-noise ratio of the detected signals. The method then establishes the terahertz link via at least one of the detected terahertz signals with a highest signal-to-noise ratio. | 04-26-2012 |
| 20120106951 | IN-BAND OPTICAL SIGNAL-TO-NOISE RATIO MEASUREMENT - Various embodiments relate to an in-band measurement of the optical signal-to-noise ratio (OSNR) of an optical signal in an optically-amplified transmission system. A demodulation device may tap a transmission fiber to receive an optical signal containing a low-frequency signal. A filter may implement first and second passbands to filter portions of an optical channel in the optical signal. Once the filtered channel is converted to first and second target electrical signals, a measurement circuit may take measurements of DC and AC components for each of the target electrical signals. Based on measurements of the two target electrical signals, the demodulation device may calculate the OSNR as a function of the DC and AC components, or as a function of the adjustment factors between first and second passbands of the optical channel represented by the first and second target electrical signals. | 05-03-2012 |
| 20120114329 | Optical Impairment Aware Path Computation Architecture in PCE Based Network - An apparatus comprising at least one processor configured to implement a method comprising receiving a path computation request comprising at least one path computation constraint, and determining whether there is a path through an optical network that satisfies the path computation constraints. Also disclosed is an apparatus configured to process a data structure comprising a flags field comprising at least one flag having one of an active state or an inactive state, wherein each flag is representative of an optical quality constraint. | 05-10-2012 |
| 20120114330 | MONITORING OPTICAL PARAMETERS OF A MODULATED OPTICAL SIGNAL - A method of monitoring optical parameters of a modulated optical signal comprises receiving a first optical power, X | 05-10-2012 |
| 20120155861 | METHOD AND DEVICE FOR DETECTING INBAND OPTICAL SIGNAL TO NOISE RATIO - A method and a device for detecting Inband Optical Signal to Noise Ratio (OSNR) are provided in the present invention, wherein the method includes the following steps: obtaining a signal power P | 06-21-2012 |
| 20120177365 | Secure Data Transmission Using Spatial Multiplexing - An example apparatus includes a mode selective detector, a measurement module, a difference calculator and a threshold and alarm module. The mode selective detector detects a plurality of modes of a spatially multiplexed signal. The measurement module measures a parameter for the plurality of modes of the spatially multiplexed signal, wherein the parameter is a power or a signal to noise ratio (SNR). The difference calculator compares the measured parameter among a subset modes and/or among a known set of unperturbed parameters and determines a differential, the subset including at least one mode. The threshold and alarm module sets an alarm indicator when the differential is out of bounds. | 07-12-2012 |
| 20120189300 | TESTING OF RECEIVERS WITH SEPARATE LINEAR O/E MODULE AND HOST USED IN COMMUNICATION LINKS - A receiver for a communications link includes a receiver module and a host receiver. These two components can be tested independently. In one embodiment, the receiver module is characterized with respect to noise and distortion. The noise performance can be determined by comparing input and output signals of the receiver module, to determine the relative noise of the receiver module. The distortion performance can be determined by comparing the distortion of input and output signals of the receiver module, using a reference host receiver that includes an equalizer. The host receiver can be tested by using a reference receiver module. | 07-26-2012 |
| 20120195590 | MEASURING PHASE NOISE IN RADIO FREQUENCY, MICROWAVE OR MILLIMETER SIGNALS BASED ON PHOTONIC DELAY - Techniques and devices for measuring phase noise in radio frequency (RF), microwave, or millimeter signals based on photonic delay. | 08-02-2012 |
| 20120201533 | Reference-Based In-Band OSNR Measurement on Polarization-Multiplexed Signals - There is provided a method for determining an in-band noise parameter, such as the Optical Signal-to-Noise Ratio (OSNR), on an optical signal-under-test (SUT) propagating along an optical communication link and comprising a data-carrying signal contribution of any arbitrary degree of polarization and a noise contribution. A spectral shape trace of signal contribution in the SUT is estimated using a reference optical spectrum trace of a reference signal which comprises a signal contribution that is spectrally representative of the signal contribution of the SUT and a noise contribution which is at least approximately known. The signal contribution is mathematically discriminated from said noise contribution in the SUT using the spectral shape trace and the test optical spectrum trace. The in-band noise parameter is then determined at least from the mathematically discriminated noise contribution. | 08-09-2012 |
| 20120219285 | IN-BAND OPTICAL SIGNAL TO NOISE RATIO MONITORING TECHNIQUE - A monitor for monitoring OSNR of data being carried via an optical network link, the monitor obtains an optical signal from the link, comprises a loop of a non-linear optical medium capable of producing a back reflected signal to the optical signal and of looping the back reflected signal; and comprises a device for extracting a portion of the looped back reflected signal from said loop. The monitor further comprises a first photodetector for measuring power of the optical signal and a second photodetector for measuring power of the extracted portion of the looped signal. Finally, there is a processing unit for determining OSNR of the optical signal based at least on readings of the first and the second photodetectors. | 08-30-2012 |
| 20120237211 | OPTICAL RECEIVING APPARATUS - There is provided an optical receiving apparatus, including a receiver configured to perform coherent reception by mixing first light of a received optical signal and second light generated by a local oscillator, a monitor configured to monitor a first frequency of the first light, and a controller configured to control a second frequency of the second light, based on a difference between the first frequency and the second frequency so as to reduce the difference. | 09-20-2012 |
| 20120237212 | OPTICAL NETWORK SYSTEM - There is provided an optical network system in which optical signals modulated by each of at least two modulation methods are wavelength-division-multiplexed and transferred, including: an optical transmitter configured to transmit first optical signals modulated by each of at least two modulation methods; an add-drop multiplexer configured to drop second optical signals from wavelength-division-multiplexed optical signals transferred in the optical network system, and add the first optical signals to the wavelength-division-multiplexed optical signals; an optical receiver configured to demodulate the second optical signals corresponding to each of at least two modulation methods; and a controller configured to control wavelengths of the first optical signals, the second optical signals and the wavelength-division-multiplexed optical signals so as to rearrange wavelengths of the first optical signals, the second optical signals and the wavelength-division-multiplexed optical signals so that optical signals modulated by a same modulation method are placed on an adjacent wavelength. | 09-20-2012 |
| 20120269506 | METHOD AND SYSTEM FOR AN ADAPTIVE CHANNEL GRID OF AN OPTICAL NETWORK - In accordance with an embodiment of the present disclosure a method for adaptively spacing channels of an optical network comprises determining a first desired power level of a first channel of an optical network. The method further comprises determining a second desired power level of a second channel of the optical network, the second desired power level being less than the first desired power level. Additionally, the method comprises determining a first spectral space between the first channel and one or more channels neighboring the first channel based at least on the first desired power level. The method also comprises determining a second spectral space between the second channel and one or more channels neighboring the second channel based at least on the second desired power level, the second spectral space less than the first spectral space. | 10-25-2012 |
| 20120301139 | OPTICAL PACKET SWITCHING SYSTEM - An optical packet switching system includes an optical packet generator for generating an optical packet signal, an optical packet switching unit, provided with an optical switch, for switching the route of an inputted optical packet signal by controlling on/off of the optical switch, and an optical signal-to-noise ratio measuring unit for measuring the optical signal-to-noise ratio of the optical packet signal outputted from the optical packet switching unit. When switching the route of the optical packet signal, the optical packet switching unit outputs an optical packet signal with optical noise by keeping the optical switch on longer than the time width of the packet signal. The optical signal-to-noise ratio measuring unit measures the optical signal power and the optical noise power, respectively, in the optical packet signal with optical noise and measures the optical signal-to-noise ratio by calculating the ratio between the optical signal power and the optical noise power. | 11-29-2012 |
| 20120321297 | ROUTING AND VALIDATION OF PATHS IN A WAVELENGTH SWITCHED OPTICAL NETWORK - A network comprises nodes connected by optical sections. The nodes support a plurality of traffic types. A candidate optical path having a first traffic type is selected as a routing for at least part of the connection on the basis of at least one routing metric. Pre-computed parameters are retrieved for the optical sections of the candidate optical path. The pre-computed parameters are indicative of quality of transmission along the optical section for the first traffic type. A quality of transmission is determined along the candidate optical path using the retrieved parameters. The pre-computed parameters for each of the optical sections can be used at a network planning tool and then exported to a network management system or a path computation entity at a node for creating a validation module for use in validating connections across the optical transmission network. | 12-20-2012 |
| 20130016967 | OPTICAL PACKET SWITCHING APPARATUSAANM Sato; ReikoAACI Kawasaki-shiAACO JPAAGP Sato; Reiko Kawasaki-shi JP - An optical packet switching apparatus includes an optical switch unit for switching the route of an optical packet signal, an OSNR acquiring unit for obtaining the information on the optical-to-noise ratio (OSNR) of the optical packet signal, and a regenerative relay unit for regenerating and relaying the optical packet. When the OSNR of the optical packet signal is less than a predetermined reference value, the optical switch unit outputs the optical packet signal to the regenerative relay unit. The regenerative relay unit sends back the regenerated optical packet to a route through which the optical packet is supposed to be sent out. | 01-17-2013 |
| 20130028597 | METHOD AND APPARATUS FOR DETERMINING AN OPTICAL SIGNAL-TO-NOISE RATIO (OSNR) PENALTY - A method for determining an optical signal-to-noise ratio penalty as a measure for a quality of an optical signal transmitted via an optical link between a source optical node and a destination optical node in an optical network, the method includes collecting information of the optical link; determining a configuration parameter P | 01-31-2013 |
| 20130039650 | OPTICAL PACKET SWITCHING SYSTEM - An optical packet switching system includes a plurality of network elements for transmitting and receiving optical packet signals. Each network element includes an optical signal-to-noise ratio (OSNR) acquiring unit for acquiring the OSNR of each optical packet signal, an average value calculating unit for calculating the average value of the OSNRs of optical packet signals received within a predetermined time duration for each of the plurality of source network elements, and a difference information transmitter for calculating the difference between the calculated average value of the OSNRs and a target value of the OSNRs and then transmitting the difference to a network element corresponding to the difference. A source network element that has received the difference information adjusts the characteristics of an optical packet signal to be transmitted in a manner such that the difference is reduced. | 02-14-2013 |
| 20130039651 | QUALITY OF SERVICE IN AN OPTICAL NETWORK - A method and apparatus for performing a path based quality check for a specified bit rate in a wavelength division multiplexing optical network is described. According to one embodiment of the invention, a method selects from a database one of the available paths as a currently selected path. The database stores a representation of the available paths from an access node of the optical network to other access nodes of the optical network. The method further determines a cumulative noise, cumulative chromatic dispersion, and a maximum allowable chromatic dispersion for the currently selected path. In addition, the method determines whether the currently selected path passes the path based quality check based on whether the cumulative noise is less than the maximum allowable noise at a specific bit rate and whether the chromatic dispersion is less than the maximum allowable chromatic dispersion at the specified bit rate. | 02-14-2013 |
| 20130121689 | OPTICAL AMPLIFYING DEVICE AND OPTICAL TRANSMISSION SYSTEM - An optical amplifying device includes an optical amplification medium configured to be excited by excitation light and amplify signal light, a light loss detector configured to detect a light loss of an optical component optically connected to the optical amplification medium in the amplifying device, and a noise figure deterioration detector configured to detect, based on the light loss detected by the light loss detector, deterioration of a noise figure of the optical amplification medium. | 05-16-2013 |
| 20130129348 | SUBCARRIER POWER BALANCE CONTROL - A method of controlling a multiple sub-carrier optical channel of an optical communications system. The multiple sub-carrier optical channel includes at least two sub-carriers modulated with respective sub-channel data streams within a spectral range allocated to a single optical channel of the optical communications system. A transmitter modem of the optical communications system applies a respective dither signal to each sub-carrier. A receiver modem of the optical communications system detects a respective quality metric of each sub-carrier. A respective optimum power level of each sub-carrier is estimated based on the applied dither signals and the detected quality metrics. A respective power level of each sub-carrier is then adjusted in accordance with the estimated respective optimum power level of each sub-carrier. | 05-23-2013 |
| 20130142508 | CONFIGURING A PATH IN AN OPTICAL COMMUNICATIONS NETWORK - A method of configuring a path between an ingress node and an egress node in an optical communications network, the path comprising a first hop and a subsequent hop. The method includes: a) selecting a candidate hop for the first hop of the path; b) obtaining a value of a signal feasibility parameter for the candidate hop; c) determining whether said value lies within an acceptable value range and if one is, accepting said candidate hop for the first hop of the path, and if one is not, repeating steps a. to c.; d) selecting a candidate hop for the subsequent hop of path; e) obtaining a value of a signal feasibility parameter for a combined path comprising the first hop and the candidate hop for the subsequent hop of the path; f) determining whether said value lies within an acceptable value range, if one is, acceptable value range accepting said candidate hop for the subsequent hop of the path, and if one is not, repeating steps d. and e.; and g) generating and transmitting a control signal for configuring the path. Each step of obtaining a value of a signal feasibility parameter comprises checking whether a measured value of the signal feasibility parameter is available, and if one is, retrieving said measured value and if one is not, calculating an estimated value of the signal feasibility parameter. | 06-06-2013 |
| 20130163987 | METHOD AND SYSTEM FOR DETERMINING IN-BAND OPTICAL NOISE - There is provided a method for determining the in-band noise in agile multichannel Dense Wavelength Division Multiplexing (DWDM) optical systems, where the interchannel noise is not representative of the in-band noise in the optical channel. The method relies on the analysis of two observations of the same input optical signal. In the two observations, the linear relationship between the optical signal contribution and the optical noise contribution (e.g. the observed OSNR) is different, which allows the discrimination of the signal and noise contributions in the input optical signal. In a first approach, the two observations are provided by polarization analysis of the input optical signal. In a second, the input optical signal is obtained using two different integration widths. | 06-27-2013 |
| 20130170828 | Monitoring and Controlling Optical Nodes - A method and apparatus for monitoring and controlling an optical node | 07-04-2013 |
| 20130209091 | HIGH SPEED OPTICAL COMMUNICATION SYSTEMS AND METHODS WITH FLEXIBLE BANDWIDTH ADAPTATION - A fiber optic system includes a transmitter configured to utilize a plurality of modulation formats and a receiver communicatively coupled to the transmitter and configured to utilize a plurality of modulation formats. The transmitter and the receiver are cooperatively configured to set a modulation format of the plurality of modulation formats based upon optical signal-to-noise ratio associated therewith. A flexible bandwidth adaptation method includes monitoring at least one aspect of an optical link at a network element, responsive to the at least one aspect, computing a new modulation scheme for the optical link, and, if a solution is found for the new modulation scheme, changing to the new modulation format. | 08-15-2013 |
| 20130223839 | METHOD AND APPARATUS FOR PROVIDING COMMUNICATION USING A TERAHERTZ LINK - A method and apparatus for establishing a terahertz link using a multi-element lens array that comprises a liquid lens are disclosed. For example, the method receives detected terahertz signals from one or more detectors, where a liquid lens is deployed with each of the one or more detectors. The method determines, for each of the detected signals, if the detected signal is out of focus, and applies a corrective voltage to each liquid lens that corresponds to a detected terahertz signal that is out of focus, wherein the corrective voltage adjusts a focus of the detected signal. The method measures a signal-to-noise ratio of the detected signals, and establishing a terahertz link via at least one of the detected terahertz signals with a highest signal-to-noise ratio. | 08-29-2013 |
| 20130236171 | MULTIPLE SENSOR OPTICAL COMMUNICATION SYSTEMS AND METHODS - An optical communication system has a receiver that includes a plurality of photon counting sensors that each receive photons and generate pulses based on the received photons, and an electronic circuit that aggregates the number of pulses from the plurality of photon counting sensors into a merged pulse count. A demodulator samples the merged pulse count at predetermined time intervals to determine a number of photons received by the plurality of photon counting sensors during different sampling time intervals. | 09-12-2013 |
| 20130272697 | OSNR Model For Optical Engineering Rules Used In A Planning Tool - Increasing data rates in next-generation optical networks requires a change in the type of optical modulation used to encode optical signals carried by the optical networks. Different types of optical modulation incur different optical impairments, which may degrade the fidelity of the optical signals by reducing the optical signal-to-noise ratio (OSNR). A method or corresponding apparatus in an example embodiment of the present invention provides a planning tool for deploying an optical network in a manner based on the optical modulation that reduces the cost and complexity of the deployed network. In one embodiment, the disclosed planning tool may adjust a model of the optical network to be deployed by changing the topology and/or the number and/or type of optical network elements in response to optical impairments for a given optical modulation. | 10-17-2013 |
| 20130287390 | DIGITAL FILTER DEVICE, DIGITAL FILTERING METHOD AND CONTROL PROGRAM FOR THE DIGITAL FILTER DEVICE - In order to solve a problem of achieving distortion compensation with high accuracy, a digital filter device includes a first distortion compensation filter unit for conducting distortion compensation of first waveform distortion included in an inputted signal through digital signal processing, a first filter coefficient setting unit for setting a filter coefficient of the first distortion compensation filter unit, a second distortion compensation filter unit for compensating second waveform distortion included in a signal outputted from the first distortion compensation filter unit, and a second filter coefficient setting unit for setting a filter coefficient of the second distortion compensation filter unit based on the filter coefficient set by the first filter coefficient setting unit. | 10-31-2013 |
| 20130294766 | Dark Current Cancellation For Optical Power Monitoring In Optical Transceivers - Various embodiments of a method and device for dark current cancellation for optical power monitoring in optical transceivers are presented. In one aspect, a device includes a photosensitive module and a processing module coupled to the photosensitive module. The photosensitive module is configured to detect an optical signal and generate a first signal responsive to detecting the optical signal. The processing module is configured to determine a value of a second signal that is related to noise and determine a value of a third signal that is related to a difference between a value of the first signal and the value of the second signal. | 11-07-2013 |
| 20130330072 | REDUCING COHERENT NOISE IN SINGLE FIBER TRANSCEIVERS - A method includes monitoring, by a transceiver, a first wavelength corresponding to a transmitted optical signal. The method includes monitoring a second wavelength corresponding to a received optical signal. The method also includes determining whether the first wavelength is identifiably different than the second wavelength. The method includes maintaining a separation between the first and second wavelengths if the first and second wavelengths are identifiably different. The first and second wavelengths are separated if the first and second wavelengths are not identifiably different. The method further includes maintaining the separation between the first and second wavelengths following separation of the first and second wavelengths. | 12-12-2013 |
| 20130336648 | METHOD AND APPARATUS FOR PROVIDING BEAM STEERING OF TERAHERTZ ELECTROMAGNETIC WAVES - A method and apparatus for establishing a terahertz link using a multi-element lens array that comprises a plurality of active beam steering device are disclosed. For example, the method receives detected terahertz signals from one or more detectors, where an active beam steering device is deployed with each of the one or more detectors, and determines, for each of the detected signals, if the detected signal is out of focus from a focus point. The method applies a corrective signal to each active beam steering device that corresponds to a detected terahertz signal that is out of focus from the focus point, wherein the corrective signal causes the detected signal to be redirected, and measures a signal-to-noise ratio of the detected signals. The method then establishes the terahertz link via at least one of the detected terahertz signals with a highest signal-to-noise ratio. | 12-19-2013 |
| 20140023362 | POLARIZATION DEPENDENT LOSS COMPENSATION - An apparatus including a polarization controller is described. The polarizer controller is communicatively coupled via a feedback loop to an evaluation module located near an optical receiver. The evaluation module is configured to measure polarization dependent loss (PDL) of an optical signal received at the optical receiver. The polarization controller is configured to receive feedback control data regarding the PDL from the evaluation module. Additionally, the polarization controller is configured to modify a state of polarization of the optical signal at an optical transmitter, which is communicatively coupled to the optical receiver, based on the feedback control data. | 01-23-2014 |
| 20140029937 | METHOD, APPARATUS, AND SYSTEM FOR MONITORING AND ADJUSTING OPTICAL POWER - The present disclosure provides a method for monitoring and adjusting optical power, where the method includes: according to a characteristic of a service, calculating a degraded coefficient corresponding to each service; according to a nominal signal-to-noise ratio input and a nominal power input which are between nodes, calculating a nominal signal-to-noise ratio output between the nodes; according to the nominal signal-to-noise ratio input and the nominal signal-to-noise ratio output between the nodes, calculating a nominal degraded degree of an OSNR between the nodes; according to the degraded coefficient corresponding to each service, and the nominal degraded degree of the OSNR between the nodes, calculating a target degraded degree of each service between the nodes; according to the target degraded degree of each service between the nodes, calculating a target optical power adjusting value of each service at a sending end node; and adjust optical power of each service. | 01-30-2014 |
| 20140079388 | Measuring In-Band Optical Signal-To-Noise Ratio (OSNR) - One measurement system comprises a polarimeter with a polarimeter detector bandwidth that partially overlaps with a signal bandwidth or completely overlaps with a signal bandwidth. The polarimeter measures a state of polarization (SOP) or a degree of polarization (DOP) of the signal in the presence of noise. The system further comprises a sampler that receives polarimeter signals from the polarimeter and samples those received signals at a specified sampling rate. The sampler outputs sampled data to a processor that calculates a mean DOP for the samples. Subsequently, the OSNR is determined from the calculated mean DOP. | 03-20-2014 |
| 20140079389 | PATH SELECTING METHOD AND APPARATUS - Embodiments of the present invention disclose a path selecting method and apparatus. The method includes: computing an end-to-end path for a newly added service according to network topology and a wavelength constraint, and assigning a wavelength to the path; computing performance of each existing service and performance of the newly added service in a network according to physical impairment information collected in the network, where the physical impairment information includes a gain reference spectrum of each optical amplifier in the network; and performing impairment check on performance of each service, and performing path selection for the newly added service according to a result of the impairment check. The apparatus includes a path computation module, a performance computation module and an impairment check module. According to the embodiments, efficiency of network update or rerouting is improved. | 03-20-2014 |
| 20140086574 | CHARACTERIZATION OF LINEAR CROSSTALK ON MULTIPLEXED OPTICAL SIGNALS - There is provided a method of determining at least one linear-crosstalk-related parameter of an optical signal-under-test having, within an optical channel bandwidth, at least a data-carrying signal contribution and a wavelength-dependent linear-crosstalk contribution arising from a data-carrying signal contribution of an adjacent optical signal associated with an adjacent channel to the optical signal-under-test, the method comprising: acquiring at least one optical spectrum trace encompassing a quasi-continuum of closely-spaced wavelengths over a spectral range extending to at least part of both the signal under test and the adjacent optical signal; and estimating said linear-crosstalk contribution using at least spectral properties of said at least one optical spectrum trace; wherein one of said at least one linear-crosstalk-related parameter is the linear-crosstalk contribution and is determined from said estimating. | 03-27-2014 |
| 20140086575 | OPTICAL RECEIVER, OPTICAL TRANSMISSION SYSTEM, AND SPAN-LOSS MONITORING METHOD - An optical receiver includes a converter configured to convert, into an electrical signal, an optical signal including error correction information, the optical signal being received from a transmitting side; a corrector configured to correct an error on the electrical signal, based on the error correction information; a threshold controller configured to control a threshold value discriminating a power of the electrical signal, based on a result of the error correction; a table configured to form therein data of a relationship between the threshold value and a power of an optical noise occurring when the optical signal is amplified within an optical transmission path; and a deriving unit configured to obtain the power of the optical noise corresponding to the threshold value from the table. | 03-27-2014 |
| 20140133849 | OPTICAL TRANSMISSION SYSTEM, NODE APPARATUS, AND REACHABILITY DETERMINATION METHOD - A node apparatus is installed at a node located on a route from a start node to an end node, and includes: a parameter calculating unit configured to, upon receiving routing information specifying the route and a first parameter representing an amount of signal degradation, update the first parameter by using a second parameter representing an amount of signal degradation along a transmission route to an adjacent node, and generate a third parameter representing an amount of signal degradation along a transmission route between the start node and the node, specified by the routing information; and a determination unit configured to determine reachability of the route specified by the routing information in accordance with the third parameter and a fourth parameter representing an amount of signal degradation along a transmission route from the node to the end node specified by the routing information. | 05-15-2014 |
| 20140147113 | DYNAMIC EVALUATION OF THE OPTICAL MULTIPLEX SECTION PER-CHANNEL PRE-EMPHASIS POWER - An apparatus and method of pre-emphasising a launch power profile of a section in an optical network is provided. The method comprises measuring the output power at the output of the section, determining the predicted output power associated with a flat launch power profile using design characteristics of the section and determining the total power deviation between the measured output power and the predicted output power. Also, the method comprises determining the signal to noise ratio deviation and the nonlinear phase shift deviation as a function of the total power deviation, and pre-emphasising the launch power profile based on a function of the calculated signal to noise ratio deviations of each span and the calculated nonlinear phase shift deviations of each span, such that the sum of the nonlinear phase shift deviations and the sum of the signal to noise ratio deviations of each channel are reduced by an equal amount. | 05-29-2014 |
| 20140270755 | METHODS AND APPARATUSES FOR IMPROVED ETHERNET PATH SELECTION USING OPTICAL LEVELS - Methods and apparatuses are provided to employ an enhanced Loss of Signal (ELOS) function in network equipment (NE) such as an Ethernet switch that is coupled to an optical path by a transceiver (e.g., an SFP). Diagnostics such as optical path receive (Rx) level from the transceiver are used by the ELOS function to regenerate LOS status from the transceiver when either LOS or designated low Rx level conditions exist. By generating an enhanced LOS (ELOS) on a designated low Rx level, the ELOS function ensures a failing data path is removed before an undesirable amount of errors occur to enhance Ethernet path selection and improve Carrier Ethernet quality of service. | 09-18-2014 |
| 20140270756 | MEASUREMENT DEVICE, MEASUREMENT METHOD, TRANSFER DEVICE, AND OPTICAL NETWORK - A measurement device includes a first obtaining unit configured to obtain a first power ratio that indicates a ratio of optical signal power of a first wavelength in a first spectrum at a reception device to optical signal power of a second wavelength different from the first wavelength in the first spectrum; a second obtaining unit configured to obtain a second power ratio that indicates a ratio of optical signal power of the first wavelength in a second spectrum at a transmission device to optical signal power of the second wavelength in the second spectrum; a calculation unit configured to calculate an OSNR of the optical signal at the reception device using the first power ratio obtained by the first obtaining unit and the second power ratio obtained by the second obtaining unit; and an output unit configured to output the OSNR calculated by the calculation unit. | 09-18-2014 |
| 20140294378 | TRANSMISSION APPARATUS, TRANSMISSION SYSTEM, AND METHOD OF CONTROLLING AVERAGE OPTICAL INPUT POWER - A transmission apparatus includes: an amplifier controller configured to determine a target value for an average optical input power of a transmitting amplifier in a transmitting-side apparatus, based on an index based on a quality of transmission from an output of the transmitting amplifier to an output of a receiving amplifier in a receiving-side apparatus; and a pre-emphasis controller configured to determine amounts of adjustment of transmission optical powers for respective wavelengths, based on the target value and per-wavelength reception optical powers at the output of the receiving amplifier. | 10-02-2014 |
| 20140308034 | OPTICAL SIGNAL QUALITY MONITORING METHOD AND APPARATUS USING A SOFTWARE-BASED SYNCHRONIZED AMPLITUDE HISTOGRAM - An optical signal quality monitoring apparatus includes an optical detector for directly receiving an optical signal modulated in an optical path and converting the optical signal to an electric signal, an asynchronous sampling unit for asynchronously sampling the electric signal of the optical detector at a reduced speed, and a digital signal processor for monitoring an optical signal quality by finding a synchronized amplitude histogram of data sampled in the asynchronous sampling unit. An optical signal quality monitoring method includes (a) a step of allowing an optical detector to directly receive a modulated optical signal and to convert the optical signal to an electric signal; (b) a step of allowing an asynchronous sampling unit to asynchronously sample the electric signal; and (c) a step of allowing a digital signal processor to monitor an optical signal quality by generating a synchronized amplitude histogram of sampled data. | 10-16-2014 |
| 20140314405 | Method and Apparatus for Equalizing Link Performance - Embodiments of the present invention provide a method and an apparatus for equalizing link performance, and relate to the field of optical wavelength division multiplexing. In the present invention, target input power spectra and target output power spectra in all OMS sections in a network and single wave attenuation at a power adjusting point may be concurrently calculated based on link information of the OMS sections, fast adjustment may also be implemented for a complex network topology, and the adjustment may be implemented in a one-off manner to avoid a problem that iteration adjustment is caused by mutual impact of power adjusting points during serial adjustment in a ring network. In addition, it is not required to connect an optical path in the calculation phase, thereby eliminating reliance on a connected optical path in a process for equalizing link performance. | 10-23-2014 |
| 20140328586 | SIGNAL DEFORMATION MEASUREMENT ON POLARIZATION-MULTIPLEXED SIGNALS - There is provided a method and an apparatus for determining quality parameters on a polarization-multiplexed optical signal based on an analysis of the power spectral density of the Signal-Under-Test (SUT). The method is predicated upon knowledge of the spectral shape of the signal in the absence of significant noise or spectral deformation. This knowledge is provided by a reference optical spectrum trace. Based on this knowledge and under the assumption that ASE noise level is approximately constant in wavelength over a given spectral range, the spectral deformation of the signal contribution of the SUT may be estimated using a comparison of the spectral variations of the optical spectrum trace of the SUT with that of the reference optical spectrum trace. | 11-06-2014 |
| 20140328587 | PATH COMPUTATION IN WAVELENGTH SWITCHED OPTICAL NETWORKS - A path computation client (PCC) can request a path computation element (PCE) to compute a path across a wavelength switched optical network. PCC sends a request which identifies end nodes. The end nodes can support a plurality of possible values of a transmission parameter, such as modulation format or Forward Error Correction (FEC) type. The PCE computes a path between the end nodes and sends a reply to the PCC. The reply identifies the path between the end nodes and identifies a selected value of the transmission parameter for the computed path. The reply can comprise a spectrum assignment for the path. The reply can be a PCE Communication Protocol (PCEP) Reply message. | 11-06-2014 |
| 20140334814 | Adaptive Optical Amplifier for WDM Systems - An optical amplifier that uses software-defined optical networking (SDON) technology, with a centralized controller and flexible physical hardware (the adaptive amplifier here) to optimize the power distribution among different WDM channels in the amplifier. It considers the detailed information for each channel through the information from centralized controller. It is suitable for both single line rate and mixed line rate system, and is suitable for a wavelength division multiplexing WDM system with the same signal type or different signal types. | 11-13-2014 |
| 20140369678 | DUAL-POLARIZATION INTERFEROMETRIC OPTICAL SIGNAL-TO-NOISE RATIO MONITOR - The present disclosure includes a method of determining optical signal-to-noise ratio (OSNR) of a signal, comprising separating one polarization component from a plurality of polarization components in an optical signal, selecting one wavelength from a plurality of wavelengths in the optical signal, delaying a first portion of the one polarization component of the one wavelength of the optical signal, shifting a phase of the first portion by a first amount and the first amount plus pi radians, causing the first portion to interfere with a second portion, measuring a power of the interference of the first and second portions, receiving the power of the interference, and comparing the power of the interference when the phase is shifted by the first amount with the interference when the phase is shifted by the first amount plus pi radians to determine OSNR. The present disclosure also includes associated devices. | 12-18-2014 |
| 20140369679 | ASYMMETRIC COMPENSATION OF POLARIZATION DEPENDENT LOSS IN DUAL-POLARIZATION OPTICAL SYSTEMS - Methods and systems for asymmetrically compensating degradation of an optical signal-to-noise ratio (OSNR) induced by polarization dependent loss (PDL) in dual-polarization optical system include using an OSNR compensator. The OSNR compensator may separate the dual-polarization components and determine which component has degraded OSNR. The degraded component may be OSNR compensated using a phase-sensitive amplifier and/or a regenerator with a phase-sensitive amplifier. | 12-18-2014 |
| 20140376907 | MITIGATION OF OPTICAL SIGNAL TO NOISE RATIO DEGRADATION ARISING FROM POLARIZATION DEPENDENT LOSS - Methods and systems for mitigating degradation of an optical signal-to-noise ratio (OSNR) induced by polarization dependent loss (PDL) in an optical network include determining an increase in power (ΔP) corresponding to a PDL-induced decrease in OSNR for a given channel being transmitted over an optical signal transmission path. The increase in power (ΔP) may be adjusted for at least some of the network nodes in the optical signal transmission path. At certain network nodes, the increase in power (ΔP) may be realized with a combination of attenuation and gain. | 12-25-2014 |
| 20140376908 | SYSTEM AND METHOD FOR MONITORING A DUAL-POLARIZATION SIGNAL USING AN IN-BAND SUPERVISORY SIGNAL - Systems and method for monitoring an optical power of a dual-polarization signal are disclosed. The systems and methods may include measuring a first parameter set associated with a supervisory signal, the supervisory signal being communicated in-band with the dual-polarization signal; calculating a second parameter set from the first parameter set; calculating an intensity value from the second parameter set, the intensity value associated with one of the polarization states of the dual-polarization signal; and estimating a signal power associated with the supervisory signal from the intensity value. | 12-25-2014 |
| 20140376909 | Optical Channel Monitor With High Resolution Capability - Described herein is an optical channel monitor ( | 12-25-2014 |
| 20150010299 | METHOD, APPARATUS, NODE DEVICE AND NETWORK SYSTEM FOR DETECTING OPTICAL SIGNAL-TO-NOISE RATIO - The present invention discloses a method and an apparatus for detecting an optical signal-to-noise ratio, a node device, and a network system. The method includes: receiving a detected optical signal carrying amplified spontaneous emission ASE noise; detecting a first alternating current component and a first direct current component of the detected optical signal; acquiring first modulation information of the detected optical signal; acquiring first correction information corresponding to the first modulation information according to the first modulation information; and determining an optical signal-to-noise ratio OSNR of the detected optical signal according to the first alternating current component, the first direct current component, and the first correction information. | 01-08-2015 |
| 20150110486 | IN-BAND OSNR MEASUREMENT ON POLARIZATION-MULTIPLEXED SIGNALS - There is provided a system and a method for determining an in-band noise parameter representative of the optical noise contribution (such as OSNR) on a polarization-multiplexed optical Signal-Under-Test (SUT) comprising two polarized phase-modulated data-carrying contributions and an optical noise contribution. For each of a multiplicity of distinct polarization-analyzer conditions, the SUT is analyzed to provide at least one polarization-analyzed component of the SUT and the polarization-analyzed component is detected with an electronic bandwidth at least ten times smaller than the symbol rate of the SUT to obtain a corresponding acquired electrical signal; for each acquired electrical signal, a value of a statistical parameter is determined from the ac component of the acquired electrical signal, thereby providing a set of statistical-parameter values corresponding to the multiplicity of distinct polarization-analyzer conditions; and, from the set of statistical-parameter values, the in-band noise parameter is mathematically determined. | 04-23-2015 |
| 20150131988 | METHOD AND APPARATUS FOR MONITORING MECHANICAL FIBER STRESS OF OPTICAL FIBER SPANS - The length of the optical fiber section under tension expands by a certain amount that is proportional to the level of tension applied to it. Monitoring the variations in the phase of the arriving signal allows to discover a fiber that is subject to a certain level of mechanical tension. With the method and apparatus according to the present invention it is possible to protect optical communication channels against failures in an optical transmission fiber that are caused by any kind of mechanical disturbances. | 05-14-2015 |
| 20150304035 | METHOD OF OPTIMIZING OPTICAL SIGNAL QUALITY IN AN OPTICAL COMMUNICATIONS LINK, OPTICAL NETWORK ELEMENT AND OPTICAL COMMUNICATIONS LINK - A method of optimizing optical signal quality in an optical communications link comprising a plurality of sections each comprising an optical amplification apparatus and an optical fibre span, the method comprising: for each section, determining a respective optimal optical channel power which minimizes a sum of an indication of a respective linear optical noise and an indication of a respective nonlinear optical noise; and generating and transmitting at least one control signal arranged to cause a target optical channel power of each section to be set to the respective optimal optical channel power. | 10-22-2015 |
| 20150333825 | Flexible placement of spectral inverters in optical networks - Methods and systems are provided for flexible placement of spectral inverters in an optical network. The method includes identifying a first transmission path coupling a transmitter and a receiver. The first transmission path includes a first node for assignment of a first spectral inverter. The method further includes estimating a first optical signal-to-noise ratio (OSNR) penalty of nonlinear phase noise (NLPN) on the first transmission path with the first spectral inverter assigned to the first node, and based on the first estimated OSNR penalty of NLPN being less than an NLPN penalty threshold, assigning the first spectral inverter to the first node. | 11-19-2015 |
| 20150349880 | APPARATUS AND METHOD FOR MONITORING IN-BAND OSNR - An apparatus and a method for monitoring in-band OSNR (Optical Signal-to-Noise Ratio) which monitors the in-band OSNR by using two parallel Mach-Zehnder-interferometers with different optical time delays are disclosed. The apparatus and method can be resistant to chromatic dispersion, polarization mode dispersion and polarized noise, can measure the coherence characteristics of the signal without removing the noise, and can be manufactured into a semiconductor integrated device and be applied in the future high-speed optical network. | 12-03-2015 |
| 20150349887 | METHODS AND APPARATUS FOR EFFICIENT JOINT POWER LINE AND VISIBLE LIGHT COMMUNICATION - A hybrid communications system implements different communication technologies to communicate data and information for particular communications directions in different portions of the system. Power line communications (PLC) signaling is used to deliver data and information from a gateway device to a light access point. Visible light communications (VLC) signaling is used to communicate data and information from the light access point to a user equipment (UE) device. Wireless radio signaling, wireless infrared (IR) signaling, or a combination of wireless IR signaling and PLC signaling is used to communicate data/information from the UE device to the gateway device. To efficiently control the VLC communications channel between the light access point and UE device, the UE device measures the VLC channel, e.g., calculating SNRs on a per VLC tone basis, and communicating VLC channel quality feedback information to the gateway device, which is forwarded to the light access point. | 12-03-2015 |
| 20150351112 | METHOD AND APPARATUS FOR PROVIDING BEAM STEERING OF TERAHERTZ ELECTROMAGNETIC WAVES - A method and apparatus for establishing a terahertz link using a multi-element lens array that comprises a plurality of active beam steering device are disclosed. For example, the method receives detected terahertz signals from one or more detectors, where an active beam steering device is deployed with each of the one or more detectors, and determines, for each of the detected signals, if the detected signal is out of focus from a focus point. The method applies a corrective signal to each active beam steering device that corresponds to a detected terahertz signal that is out of focus from the focus point, wherein the corrective signal causes the detected signal to be redirected, and measures a signal-to-noise ratio of the detected signals. The method then establishes the terahertz link via at least one of the detected terahertz signals with a highest signal-to-noise ratio. | 12-03-2015 |
| 20150365165 | OPTICAL SIGNAL-TO-NOISE RATIO (OSNR) MONITORING AND MEASUREMENT IN OPTICAL COMMUNICATIONS SYTEMS - Disclosed are methods for monitoring and measuring Optical Signal-To-Noise Ratios in optical communications systems. One exemplary method involves intentionally inserting zero power symbols into an optical signal stream such that those periods of time in which only zero power symbols are transmitted may be detected and compared with periods of time in which signals modulated with information including both signal and noise are detected such that the OSNR may be determined. | 12-17-2015 |
| 20150372762 | Single Carrier Flexible Bit Rate Transceiver for Coherent Optical Network - An apparatus comprising a digital signal processor (DSP) configured to code a plurality of data sub-streams using a plurality of modulation formats to generate a plurality of coded data symbols, wherein each modulation format leads to a unique bit rate for coded data symbols associated with a modulation format, transform the coded data symbols into a frequency domain by applying Fourier transform on each coded data symbol, map the frequency-transformed data symbols onto a plurality of subcarrier signals associated with a plurality of frequency tones, wherein at least two of the subcarrier signals correspond to different modulation formats, and generate an electrical signal in a time domain based on the subcarrier signals. | 12-24-2015 |
| 20160056891 | OPTICAL SIGNAL-TO-NOISE RATIO MEASURING METHOD - An OSNR measuring method, comprising: measuring a spectrum to be measured of an optical signal at a point to be measured of an optical transmission line, and acquiring the comparative spectrum of the optical signal within a channel wavelength range and at an SNR different from the SNR of the point to be measured; respectively integrating, within the channel wavelength range of the optical signal, the spectrum to be measured and the comparative spectrum to obtain total power Pspectrum to be measured and Pcomparative spectrum, and acquiring a noise factor F and a signal scale factor A; calculating, according to the total power, the noise factor and the signal scale factor, the noise power Pspectrum to be measured within the channel wavelength range of the optical signal, so as to obtain an OSNR of the point to be measured. | 02-25-2016 |
| 20160072579 | A SYSTEM AND A METHOD FOR GENERATING INFORMATION INDICATIVE OF AN IMPAIRMENT OF AN OPTICAL SIGNAL - A method for generating information indicative of an impairment of an optical signal, such as a decrease in the OSNR is disclosed. The OSNR may be measured without interpolating out of band noise to in-band noise. Consequently, the optical OSNR of the optical signal after propagating through a reconfigurable network may be determined. The method comprises the step of establishing a spectral model of the optical signal within the optical signal's frequency band, the spectral model comprising a spectral impairment profile added to a model spectrum of the optical signal before the impairment, measuring the spectrum of the optical signal to generate in-band optical signal spectrum information indicative of the spectrum of the optical signal within the optical signal's band and determining at least one value of the spectral impairment profile by applying the spectral model of the optical signal to the in-band optical signal spectrum information. | 03-10-2016 |
| 20160094307 | OPTICAL TRANSMISSION DEVICE AND OPTICAL TRANSMISSION SYSTEM - An optical transmission device includes a reception unit that receives a first signal light and a second signal light, the first and second lights having power levels that respectively correspond to transmission distances and being transmitted; an amplification unit that amplifies the first signal light and the second signal light in accordance with a signal light having a high power level from among the received first signal light and second signal light; and a transmission unit that performs transmission of the amplified first signal light and second signal light. | 03-31-2016 |
| 20160112121 | OPTICAL COMPONENT, BUILT-IN OPTICAL TIME DOMAIN REFLECTOMETER, AND OPTICAL NETWORK DEVICE - An optical component, including: a component base, a transmitter module connected to the component base, a receiver module, and a pigtail, where: the component base has a cavity, and a wave filtering sheet is provided inside the cavity; the transmitter module is configured to transmit a first optical signal to the pigtail; the receiver module is configured to receive a second optical signal from the pigtail; the wave filtering sheet is configured to transmit the first optical signal transmitted by the transmitter module, to enable the first optical signal to enter the pigtail; and is further configured to reflect the second optical signal received by the pigtail to the receiver module; and a reflecting light guide through-hole is opened on the component base along an optical path direction that the light filtering sheet reflects the first optical signal. | 04-21-2016 |
| 20160112122 | SIGNAL TO NOISE RATIO ESTIMATION IN OPTICAL COMMUNICATION NETWORKS - Optical signal to noise ratio within a band of interest (in-band OSNR) is calculated by using a reference signal for noise estimation. In-band noise at a node along the optical communication path is estimated by subtracting the reference signal contribution from the received in-band signal energy. Contribution from the reference signal is calculated using an effective transfer function of the optical communication path using either a direct method in which measurements are made a priori on an equivalent optical system or an indirect method in which the effective transfer function is calculated using computerized simulations. The selection of which method to use may be based on the desired resolution bandwidth for the estimation of transfer function. | 04-21-2016 |
| 20160127074 | IN-BAND NOISE AND/OR SPECTRAL DEFORMATION MEASUREMENT ON POLARIZATION-MULTIPLEXED SIGNALS - There is provided a method to discriminate NLE-induced signal deformation from ASE-noise on polarization multiplexed signals, in order to measure the OSNR under NLE conditions and/or characterize the NLE-induced signal deformation. In accordance with one aspect, the method is based on the acquisition of optical spectrum traces when the (data-carrying) optical communication signal is partially or completely extinguished (ASE-noise only), as well as with a live optical communication signal. Comparing traces acquired with different conditions and/or at different dates allows discrimination of the signal contribution, the ASE-noise contribution and the NLE-induced deformations on the SUT. | 05-05-2016 |
| 20160142133 | Methods, Systems and Devices for Optical-Signal-to-Noise-Ratio Monitoring - A device for optical-signal-to-noise (OSNR) monitoring can include: a delay-line interferometer configured to connect with a tunable optical filter; and two or more power detectors to measure outputs of the interferometer; wherein one or more parameters are optimized for different transmission baud rates to improve accuracy. In addition, a method can include: connecting an input of a delay-line interferometer with an output of a tunable optical filter, and an output of the delay-line interferometer with an input of a power detector, to form an optical-signal-to-noise (OSNR) monitoring apparatus; optimizing one or more parameters of the OSNR monitoring apparatus for different transmission baud rates to improve accuracy. | 05-19-2016 |
| 20160142134 | DETERMINATION OF AN OPTICAL SIGNAL TO NOISE RATIO OF A DUAL-POLARIZATION OPTICAL SIGNAL - A method is provided for determining an optical signal to noise ratio of a dual polarization optical signal. The method includes: detecting, in the dual polarization optical signal, a modulation signal which modulates, at at least one low amplitude level that is approximately zero and at a high amplitude level, the dual polarization optical signal, and determining the optical signal to noise ratio from a measurement of the power of the modulation signal. | 05-19-2016 |
| 20160142135 | IN-BAND NOISE DETERMINATION ON OPTICAL COMMUNICATION SIGNALS - There are provided methods and devices for determining a quality parameter characterizing an optical communication signal, the methods being performed by signal detection devices. At the transmitting end, there are obtained a signal power P | 05-19-2016 |
| 20160164599 | DETERMINING IN-BAND OPTICAL SIGNAL-TO-NOISE RATIO IN POLARIZATION-MULTIPLEXED OPTICAL SIGNALS USING SIGNAL CORRELATIONS - A method and apparatus for determining in-band OSNR in optical information signals, e.g. in polarization-multiplexed QPSK and higher-order M-ary QAM signals, are disclosed. A correlation measurement of the signal amplitude or power at two distinct optical frequencies of the signal may be used to determine the in-band optical noise in the signal. A measurement of the signal power may be used to determine the OSNR based on the determined in-band noise. | 06-09-2016 |
| 20160173198 | DIGITAL NOISE LOADING FOR OPTICAL RECEIVERS | 06-16-2016 |
| 20160381443 | Routing Methods for Dual Plane Switch Architectures - A method and apparatus for routing signals through a photonic switch are provided. Optical Signal-to-Noise Ratio (OSNR) requirements for signals to be concurrently routed through the switch are determined, and incoming signal routing requests are blocked when routing same would violate OSNR requirements. Blocking may occur when a maximum allowed number M of lightpaths of same wavelength would be exceeded by admitting the request. Otherwise, signals are routed along a lightpath which satisfies the OSNR requirements. Cell Extinction Ratio in conjunction with OSNR requirements can be used to determine M. Switching cells can potentially accommodate multiple lightpaths of different wavelengths, but regular switching cells may be inhibited from accommodating multiple lightpaths of same wavelength. Routing solutions which maximize both cell sharing and cell packing may be sought. Routes that violate crosstalk limitation conditions are inhibited. | 12-29-2016 |
| 20170237484 | METHOD AND APPARATUS FOR THE DETECTION OF DISTORTION OR CORRUPTION OF CELLULAR COMMUNICATION SIGNALS | 08-17-2017 |
| 20190149231 | APPARATUS AND METHOD FOR MONITORING OPTICAL SIGNAL TO NOISE RATIO, RECEIVER AND COMMUNICATION SYSTEM | 05-16-2019 |
| 20190149232 | DETERMINING IN-BAND OPTICAL SIGNAL-TO-NOISE RATIO IN POLARIZATION-MULTIPLEXED OPTICAL SIGNALS USING SIGNAL CORRELATIONS | 05-16-2019 |
