Class / Patent application number | Description | Number of patent applications / Date published |
398027000 | Bit error rate | 56 |
20080232796 | OPTICAL SIGNAL MONITORING SYSTEM AND OPTICAL SIGNAL MONITORING METHOD - An optical signal monitoring system includes a bit rate information collecting unit and a monitoring unit. The bit rate information collecting unit gets bit rate information indicating a bit rate of an optical signal passing through an optical communication path. The monitoring unit extracts a monitoring optical signal from the optical communication path. When the bit rate information is not able to get, the monitoring optical signal is judged to be a noise. This system can make a sharp distinction between a broad optical signal whose bit rate is over 40 Gbit/sec and the ASE noise. Further, this system can correct optical signals dependently to those bit rates. | 09-25-2008 |
20080267622 | EFFICIENT AND SIMPLE BIT ERROR RATE CALCULATION ON OPTICAL TRANSPORT LAYER - Transport network interfaces operate to transport for Optical Transport Unit frames over an Optical Transport Network. Besides FEC bits for the Optical Transport Unit frames, the transmitting transport network interface provides sequences of error-determining bits for the Optical Transport Unit frames sent on working and protection communications channels. There is at least one sequence for each Optical Transport Unit frame, the number of bits in the at least one sequence much smaller than the number of bits in the Optical Transport Unit frame. The receiving transport network interface determines the bit error rates for the working and protection channels from the sequences of error-determining bits without decoding said Forward Error Correction bits and can select the working and protection channels accordingly. | 10-30-2008 |
20080285970 | Optical Signal Quality Monitoring Circuit and Optical Signal Quality Monitoring Method - The present invention provides an optical signal quality monitoring circuit and an optical signal quality monitoring method for measuring correct optical signal quality parameters when a signal bit rate is changed. The optical signal quality monitoring circuit which samples and converts an electrical signal converted from an optical signal with a given repeated frequency f | 11-20-2008 |
20090028555 | OPTICAL FILTER - An apparatus and method are provided for filtering an optical signal by wavelength. An initially polarised signal is passed through a DGD element effective to alter the polarisation state of the components of the signal according to wavelength. A polarisation filter (polariser) is then provided to attenuate light having given polarisation states from the signal, thereby attenuating the wavelengths associated with said polarisation states. The invention finds particularly utility in the domain of vestigial sideband filtering, allowing the bandwidth of signals within a wavelength division multiplexed system to be reduced without introducing the deleterious effects associated with conventional wavelength filters. | 01-29-2009 |
20090060497 | Feedback Controlled Locking of Optical Channel Signals in Optical Receivers in Wavelength Division Multiplexed (WDM) Communication Systems - Techniques, apparatus and systems for optical communications that use feedback controlled locking of optical channel signals in optical receivers in WDM communication systems, including ultra dense WDM systems. | 03-05-2009 |
20090269055 | Channel balancing algorithm - An algorithm is disclosed for performing channel balancing on channels between optical network elements within an optic-fiber communications system. The algorithm groups at least a portion of the channels into channel pairs, differentially adjusts the transmitter output power level of each of the channel pairs until the bit error ratio (BER) of at least one channel in each of the channel pairs exceeds a threshold, and records a respective power margin for each of the channels as the difference between the initial and final power levels. From the recorded power margins, a mean power margin is determined that is used to shift the transmitter output power level of each of the channels. | 10-29-2009 |
20090269056 | BIT ERROR RATE BASED SYSTEM AND METHOD FOR OPTIMIZING COMMUNICATION SYSTEM PERFORMANCE | 10-29-2009 |
20100021158 | OPTICAL COMMUNICATIONS SYSTEM WITHOUT USING A SPECIAL-PURPOSE EVALUATION SIGNAL - A subscriber terminating unit includes an error count counting portion counting an error count in a predetermined time range based on the number of corrections by an error correction function and an error count transmitting portion transmitting the error count to an office terminating unit. The office terminating unit includes an error count receiving portion receiving the error count from the subscriber terminating unit as a received error count and a correction method determining portion determining, based on the received error count, an error correction method or an error correction disuse which is used in the subscriber terminating unit. | 01-28-2010 |
20100046943 | SIMULATION OF OPTICAL CHARACTERISTICS OF AN OPTICAL FIBER - An optical communication apparatus that includes multiple optically communicative components positioned optically in series. Some of the optically communicative components may be optical fiber segments of perhaps different types. The optical channel represented by the series of optically communicative components and approximates a transfer function of an optical channel of a longer optical fiber. Accordingly, rather than deal with a lengthy optical fiber, an apparatus having a shorter optical channel may be used instead. The construction of the optical communicative components may be calculating an input transfer function. The construction would include an ordering of discrete optically communicative components that, when placed optically in series, simulates an estimation of a particular transfer function. Testing may then occur by actually passing an optical signal through the series construction of optically communicative components, rather than through the longer optical fiber. | 02-25-2010 |
20100239245 | Polarization Mode Emulators and Polarization Mode Dispersion Compensators Based on Optical Polarization Rotators with Discrete Polarization States - Systems, devices and techniques for generating and analyzing states of polarization in light using multiple adjustable polarization rotators having different discrete polarization rotation states in various applications. | 09-23-2010 |
20100290780 | DATA TRANSMISSION METHOD AND NETWORK FOR TRANSMITTING A DIGITAL OPTICAL SIGNAL OVER OPTICAL TRANSMISSION LINKS AND NETWORKS - A data transmission method for transmitting a digital optical signal over an optical transmission link includes creating a digital optical signal defining at least two service levels, each service level transporting information via a modulation scheme comprising at least three different modulation symbols. The data transmission method also includes transmitting the digital optical signal over the transmission link and receiving the transmitted digital optical signal at a remote end of the transmission link by demodulating the received signal and extracting the information of the at least two service levels. In case that the transmission performance is below a given threshold due to increased constraints of the transmission link a compensating action is taken to drop at least one of the service levels from the optical signal or to determine parameters associated with the transmission so as to increase one of the service levels to a predetermined quality level. | 11-18-2010 |
20110026918 | APPARATUS FOR VISIBLE LIGHT COMMUNICATION INDICATING COMMUNICATION QUALITY USING RGB COLOR MIXING AND METHOD THEREOF - A visible light communication apparatus of the present invention includes: a target signal receiver filtering only a signal having a target wavelength from a visible light received signal received from a transmitting terminal; a signal generator judging a reception quality of the visible light received signal by using characteristics of the signal having the target wavelength and generating a visible signal by using at least one light source having a wavelength different from the target wavelength in accordance with the reception quality; and an optical signal transmitter transmitting the signal having the target wavelength for transmitting data together with the visible signal and changing a light emitting color of a visible light transmitted signal. | 02-03-2011 |
20110085797 | ULTRA WIDE-RANGE FREQUENCY OFFSET ESTIMATION FOR DIGITAL COHERENT OPTICAL RECEIVERS - Methods and systems for receiving an optical signal using cascaded frequency offset estimation. Coherently detecting an optical signal includes compensating for a coarse laser frequency offset between a transmitting laser and a local oscillator laser by determining a maximum phase error (MPE) in the optical signal, compensating for a residual laser frequency offset between the transmitting laser and the local oscillator laser, and decoding data stored in the optical signal. | 04-14-2011 |
20110129214 | EXTENDER BOX, DATA TRANSMISSION METHOD AND PASSIVE OPTICAL NETWORK SYSTEM - An extender box (EB) includes: a downlink data sending module configured to send downlink data to first passive optical network (PON) devices; at least two uplink data receiving modules configured to receive uplink data sent from a corresponding first PON device respectively; and a duplexer configured to convert the data transmission mode used by the downlink data sending module and the uplink data receiving modules from dual-fiber transmission to single-fiber transmission to implement single-fiber bidirectional transceiving. The uplink data receiving modules have ports corresponding to uplink ports of the first PON devices on a one-to-one basis. Optical fibers of the uplink data receiving modules that are connected with the uplink ports of the first PON devices are separated from optical fiber of the downlink data sending module, where the optical fiber is connected with downlink ports of the first PON devices. A data transmission method and a PON system are also disclosed. | 06-02-2011 |
20110188852 | METHOD AND APPARATUS FOR FAST OPTICAL SIGNAL IMPAIRMENT EVALUATION - Having a fast method to perform impairment evaluation is useful for many networks. A method or corresponding apparatus according to an example embodiment of the present invention maintains a traffic engineering database of values representing characteristics of links in the network through storage of integer values representing advertised optical signal capabilities of links between the multiple optical nodes. The example embodiment determines a path through the network for optical wavelengths to be supported by the links represented in the database as a function of evaluating optical signal characteristics at each link along a possible path using the advertised optical signal capabilities and provides a selected path meeting an acceptable integrity of the optical wavelengths to a path establishment module to establish the path through the optical network. Example embodiments significantly reduce computational complexity associated with impairment evaluation and path selection in an optical network. | 08-04-2011 |
20110255865 | METHOD AND SYSTEM FOR ASCERTAINING THE MAPPING BETWEEN VIRTUAL LANES AND PHYSICAL LANES IN A MULTI-LANE TRANSCEIVER - For an apparatus which communicates data of a number of virtual lanes over a number of physical lanes, where the number of virtual lanes is different than the number of physical lanes and where a mapping between the virtual lanes and the physical lanes is not fixed, a method is provided for ascertaining the mapping between the virtual lanes and the physical lanes. The method includes: applying an impairment to a communication capability of one of the physical lanes so as to increase bit errors for data communicated via said one physical lane; determining a test bit error rate for each of the plurality of virtual lanes while the impairment is applied to the communication capability of the one physical lane; and ascertaining from the test bit error rates which of the virtual lanes is/are mapped to the one physical lane whose communication capability was impaired. | 10-20-2011 |
20110286739 | OPTICAL RECEIVER MODULE - An optical receiver module includes an optical receiver that receives and converts a plurality of optical signals depending on different polarized states into a plurality of electric signals, a bit error detector that detects a plurality of bit error rates from electric signals, a maximum value detector that detects a maximum bit error rate among bit error rates, a dispersion compensating controller that calculates a dispersion compensating value based on the maximum bit error rate, and a variable dispersion compensator that performs dispersion compensation against waveform degradation of received optical signals. Thus, it is possible to accurately search for an optimum dispersion compensating value in a transmission line susceptible to polarized dispersion. This makes it possible to stabilize dispersion compensating control on the optical receiver. | 11-24-2011 |
20110286740 | DQPSK/DPSK OPTICAL RECEIVER WITH TUNABLE OPTICAL FILTERS - An optical receiver includes a first interferometer having a plurality of arms. The optical receiver further includes first tunable optical filters connected in series with the arms of the first interferometer, where each first tunable optical filter is tuned to filter a region of overlap in the optical frequency spectrum between adjacent optical channels. | 11-24-2011 |
20120063773 | High Speed Error Detector for Fading Propagation Channels - A customized bit error rate tester that characterizes data transmission through a free space optical channel that overcomes the limitations of commercial based bit error rate testers by providing visibility into packet based channel capacity by measuring bit-level statistics not dominated by fades. In this manner, fade characteristics can be measured and a relationship between fade time and data packet lengths can be developed. Further, analog outputs provide visual real-time data link statistics. | 03-15-2012 |
20120093502 | MODE-HOP PREVENTION IN A TUNABLE LASER OF AN OPTICAL NETWORK ELEMENT - A method for data processing in an optical network element is provided. An event of a forthcoming mode-hop of a tunable laser is detected. Furthermore, a corresponding optical network element and an optical communication system with at least one such optical network element are described. | 04-19-2012 |
20120155862 | OPTICAL PACKET SWITCHING SYSTEM - An optical packet switching system includes: an optical packet switching device configured to route and output an input optical packet signal; an optical amplifier device provided in a stage subsequent to the optical packet switching device; and a control signal generation unit configured to superimpose a noise component on the optical packet signal by inducing cross talk in the optical packet switch. | 06-21-2012 |
20120219286 | Systems and Methods for Diagnostic Monitoring of Optical Modulation Amplitude at an Optical Receiver Using Automatic Gain Control - Optical receivers and a method for providing a diagnostic measurement of optical modulation amplitude at other than a signal output of an optical receiver are invented and disclosed. The method includes the steps of applying a representation of an output of an optical detector to a circuit that determines a difference between a first signal level and a second signal level that is different from the first signal level and buffering the difference between the first signal level and the second signal level received from the circuit. The optical receivers include an optical detector, a transimpedance amplifier that applies automatic gain control, a circuit that determines a difference between two signal values and a limiting post amplifier. The receivers provide a diagnostic measure that can be compared to certain thresholds relating to known bit error rates or applied in a calculation to generate an absolute optical modulation amplitude value. | 08-30-2012 |
20120219287 | Method and device for processing data in an optical network - A method and a device are provided for processing data in an optical network. The method includes the steps of events of a login scan are recorded by a first optical network element; the events are conveyed to a second optical network element; and the events are processed by the second optical network element. A communication system is described that includes the device. | 08-30-2012 |
20120224849 | OPTICAL INTERCONNECT USING OPTICAL TRANSMITTER PRE-DISTORTION - In one embodiment, the invention provides an optical interconnect comprising a transmitter for generating and transmitting an optical signal, a receiver for receiving the optical signal from the transmitter and for converting the received optical signal to an electrical signal, and a pre-transmitter distort circuit for applying a pre-transmitter distort signal to the transmitter to adjust the shape of the optical signal generated by the transmitter. Distortions are introduced into the optical signal when the optical signal is generated, transmitted to the receiver, and converted to the electrical signal. As a result of the signal applied to the transmitter by the pre-transmitter distort circuit, the optical signal generated by the transmitter has distortions to compensate for the distortions introduced into the optical signal, wherein the electrical signal, into which the optical signal is converted, has a desired shape. | 09-06-2012 |
20120230678 | OVERHEAD ADJUSTMENT SCHEME FOR PASSIVE OPTICAL NETWORKS - Embodiments of the present invention relate system and method for handling large dynamical signals in a passive optical network system and in particular for determining scheduling of bursts from a plurality of optical network units. More particularly, embodiments of the present invention relate to a system and method for determining a bit error ratio, i.e. BER in received communication data, determining, using the BER, optimized transmission scheduling of communication bursts from the optical network units, and providing a signal to the optical network units indicating the transmission scheduling of transmission bursts in accordance with the determined optimized transmission scheduling. | 09-13-2012 |
20120275783 | OPTICAL PACKET SWITCHING SYSTEM - An optical packet switching apparatus includes an optical packet switching apparatus, an optical transmitting apparatus, and an optical packet receiving apparatus. The optical packet transmitting apparatus includes a packet generator for generating a packet signal by adding the routing information to a received client signal, a BIP adding unit for adding BIP to the generated packet signal, and an electrical-to-optical converter for converting the packet signal, to which the BIP has been added, into an optical packet signal so as to be sent out. The optical packet receiving apparatus includes an electrical-to-optical converter for converting the received optical packet signal into an electrical packet signal, and a BIP comparison unit for detecting the error occurrence in the packet signal, based on the BIP added to the packet signal. | 11-01-2012 |
20120288276 | WDM OPTICAL TRANSMISSION SYSTEM AND WAVELENGTH DISPERSION COMPENSATION METHOD - A WDM optical transmission system includes a plurality of optical transmission devices, each of which include a first memory that stores a first control program that controls a dispersion compensation amount in a host device; a processor to execute the first control program; a notification frame transmission circuit that transmits an information indicating a setting value of the dispersion compensation amount and a detection result corresponding to the setting value to another device; a third memory that stores a second control program that calculates a control value of the dispersion compensation amount in the another device; and a control frame transmission circuit that transmits the control value to the another device, wherein the processor executes the second control program when a problem occurs in the another device, and controls the dispersion compensation amount in the host device when a problem occurs in the host device. | 11-15-2012 |
20120294606 | SYSTEM AND METHOD FOR ENHANCEMENT OF ETHERNET LINK LOSS FORWARDING - A system and method provide enhanced link loss forwarding in an Ethernet system to determine link degradation and to selectively block and re-establish transport between a near end device and far end device based on a SONET connection between end devices and link status detection using local packets. When an excessive number of errors are detected in an Ethernet port, a device enters a Links Off mode from a Transport mode where Ethernet ports are turned off at both ends of a circuit associated with the errors. A Block Transport mode is then entered where local packets (e.g., OAM packets) are monitored to evaluate link quality (e.g., SONET bit error rate). Transport mode is re-established when acceptable link quality is achieved for a selected period of time. | 11-22-2012 |
20120308230 | METHOD AND APPARATUS FOR CONTROLLING AN OPTICAL RECEIVER HAVING DELAY PATHS - A control apparatus for controlling an optical receiver having delay paths comprises an optical variable attenuator configured to generate a variable signal and provide the variable signal to the optical receiver; a fine control voltage controller configured to generate a variable fine control voltage and input the variable fine control voltage to one path of the delay paths of the optical receiver; a photo-diode voltage monitor configured to detect a first voltage value and a second voltage value; a bit error rate (BER) checker configured to estimate a bit error rate (BER) according to a signal output from the optical receiver; and a controller configured to set a value of the variable signal and a value of the variable fine control voltage and to estimate the fine control voltage that makes the bit error rate a minimum according to the first voltage value and the second voltage value. | 12-06-2012 |
20130039652 | SCHEME OF REMOTE CONTROL OF THE SLICING LEVEL OF A RECEIVER IN A SMART TRANSCEIVER - A scheme is described of remote control of the slicing level of a receiver in a smart SFP (or SFP+, or XFP) duplex (or BiDi, or SWBiDi) transceiver in a communication system using an operating system with OAM and PP functions, an OAM, PP & Payload Processor, a transceiver, a BERT, and an optical link in the field. | 02-14-2013 |
20130071108 | SCHEME FOR REMOTE CONTROL OF THE WAVELENGTH OF A TUNABLE TRANSMITTER IN A SMART TRANSCEIVER - A scheme is described for remote control of the wavelength of a tunable transmitter in a smart SFP transceiver, a smart SFP+ transceiver, a smart XFP transceiver, a smart duplex transceiver, a smart BiDi transceiver, or a smart SWF BiDi transceiver in a communication system using an operating system with OAM and PP functions; an OAM, PP & Payload Processor; a transceiver; an optical spectrum analyzer; a BERT; and an optical link in the field. | 03-21-2013 |
20130089323 | Optimal Combined 2R/3R Regenerators Placement Method for Line Network Topologies in Optical WDM Networks - A method for optimal combined 2R/3R regenerators placement for optical transmission includes determining an optimal placement of multiple 2R and 3R regenerators that minimizes bit error rate BER at a destination node, determining an optimal number of the 2R and 3R regenerators that minimizes a total cost while satisfying the BER at the destination node, and determining an optimal placement of the 2R and 3R regenerators along a route in the optical transmission. | 04-11-2013 |
20130156420 | ADAPTIVE FORWARD ERROR CORRECTION IN PASSIVE OPTICAL NETWORKS - A method for an adaptive forward error correction (FEC) in a passive optical network. The method comprises selecting an initial downstream FEC code to be applied on downstream data transmitted from an optical line terminal (OLT) to a plurality of optical network units (ONUs) of the PON; communicating the selected downstream FEC code to the plurality of ONUs; receiving at least one downstream bit error ratio (BER) value from at least one ONU of the plurality of ONUs, wherein the downstream BER value is measured respective to downstream data received at the at least one ONU; changing the selected downstream FEC code to a new downstream FEC code based on a plurality of downstream BER values measured by the at least one ONU; and communicating the new downstream FEC code to the plurality of ONUs. | 06-20-2013 |
20130170829 | Optical Coherent Receiver Optimization - Coherent optical receiver performance is optimized and made adaptable to changing optical channel conditions by providing feedback loops to adjust receiver parameters based on measured receiver performance. | 07-04-2013 |
20130209092 | OPTICAL COMMUNICATION APPARATUS - An apparatus has frame loss detecting unit | 08-15-2013 |
20130216219 | OPTICAL RECEIVING DEVICE - An optical receiving device includes: an optical amplifier configured to amplify a wavelength multiplexed optical signal; a demultiplexer configured to demultiplex the amplified wavelength multiplexed signal into optical signals of a plurality of wavelengths; optical receivers configured to regenerate the demultiplexed optical signals; error correction units configured to correct a bit error in the regenerated optical signals; and main control unit. The control unit adjusts RXDTV of the optical receiver for receiving optical signals of a given wavelength to the optimal value in the state where the gain of the optical amplifier is lowered from that of a normal operation such that the occurrence of bit errors in the optical signals of the other wavelengths does not exceed the correction capability of the error correction unit. | 08-22-2013 |
20130294767 | METHOD AND DEVICE FOR OPTIMIZING PERFORMANCE OF AN OPTICAL MODULE - Embodiments of the present invention provide a method and device for optimizing performance of an optical module. The optical module includes: an optical receiver, configured to receive an optical signal from an optical network, convert the optical signal into a first electrical signal, and process the first electrical signal according to a set control parameter for performance optimization, so as to obtain a second electrical signal; a connector, configured to send the second electrical signal obtained by the optical receiver to a host connected to the optical module, so that the host obtains bit error information according to the second electrical signal, and configured to receive the bit error information delivered by the host; and a processor, configured to adjust, according to the bit error information of the connector, the control parameter for performance optimization of the optical receiver. | 11-07-2013 |
20130308937 | WDM PON WITH NON TUNABLE LEGACY ONUS - In one embodiment, a media access controller includes first and second optical line terminals with a receiver for adjacent first and second wavelength ranges, respectively, and an optical network unit with a transmitter having a transmitter wavelength which drifts between the first and the second wavelength range. The media access controller is configured to assign the optical network unit to the first and the second optical line terminals, such that an optical burst transmitted by the optical network unit is received by the first optical line terminal and the second optical line terminal. The media access controller is configured to determine first and second qualities of the optical burst received by the first and second optical line terminals, respectively, and to determine an estimate of the transmitter wavelength based on the first quality and the second quality. | 11-21-2013 |
20130336649 | ADAPTIVE CONSTELLATIONS AND DECISION REGIONS FOR AN OPTICAL TRANSPORT SYSTEM - An optical transport system in which (i) an optical transmitter is configured to adaptively change an operative constellation to use a constellation that provides optimal performance characteristics for the present optical-link conditions and/or (ii) an optical receiver is configured to change shapes of the decision regions corresponding to an operative constellation to adapt them to the type of signal distortions experienced by a transmitted optical signal in the optical link between the transmitter and receiver. Under some optical-link conditions, the optical receiver might use a decision-region configuration in which a decision region corresponding to a first constellation point includes an area that is closer in distance to a different second constellation point than to the first constellation point. | 12-19-2013 |
20140161443 | End-to-End Carrier Frequency Control to Improve Bandwidth Utilization in an Optical Network - A system to provide carrier frequency control in an optical network includes a first network element monitoring performance information and a second network element coupled to the first network element by the optical network. The second network element receives performance information from the first network element using an administration channel bandwidth, and modifies a carrier frequency associated with the second network element based on the performance information such that the carrier frequency is aligned to a center of a signal channel bandwidth. A method of providing carrier frequency control includes transmitting performance information by the first network element to the second network element using an administration channel bandwidth, and modifying the carrier frequency by the second network element based on the performance information such that the carrier frequency is aligned to the center of the signal channel bandwidth. The administrative channel bandwidth can be within or outside the signal channel bandwidth. A corresponding computer-readable device is disclosed. | 06-12-2014 |
20140186029 | METHODS AND DEVICES FOR ACTIVE OPTICAL CABLE CALIBRATION - Methods and devices for laser driver calibration are disclosed. The methods and devices disclose determining first and second bit error rates for use in calibrating the laser driver. The methods and devices also disclose that if the first bit error rate associated with a first initial value is above a predetermined bit error rate, increasing the first initial value until the first bit error rate is not above the predetermined bit error rate, and if the second bit error rate associated with a second initial value is above a predetermined bit error rate, decreasing the second initial value until the second bit error rate is not above the predetermined bit error rate. In addition, the methods and devices disclose setting a calibrated parameter for the laser driver based, at least in part, on the increased first initial value and the decreased second initial value. | 07-03-2014 |
20140334815 | SYSTEM AND METHOD FOR SELECTING AN OPTICAL PATH IN AN OPTICAL NETWORK - The invention proposes a system and method for selecting an optimal optical path through which to transmit an optical signal, the optimal optical path is one of a plurality of optical paths in a transparent optical network. Each of the plurality of optical paths includes a plurality of optical elements. For each of the plurality of optical paths, a first optical signal to noise ratio is determined for each optical element in the respective optical path. Then, for each of the plurality of optical paths, nonlinear distortions caused by each optical element in the respective optical path are modelled as Gaussian noise and a second optical signal to noise ratio associated with the modelled Gaussian noise is determined. Finally, the optimal optical path is selected using the sums of the first and second optical signal to noise ratios, respectively. | 11-13-2014 |
20140348500 | OPTICAL RECEIVER AND SLICE LEVEL CONTROL METHOD - An optical receiver includes a first discriminator in which an optimal point of a slice level is set and that compares a received signal to the slice level and discriminately outputs the received signal; a second discriminator that is connected in parallel to the first discriminator, compares the received signal to a slice level, and discriminately outputs the received signal; and a computing device that variably controls the slice level of the first and the second discriminators, respectively. The computing device executes a first process of setting the slice level of the first discriminator to be a predetermined slice level, calculating a pseudo error rate obtained when the slice level of the second discriminator is caused to variably scan, and setting the slice level of the first discriminator within a range in which the error rate does not vary. | 11-27-2014 |
20140355979 | System and Method for an Optical Coupler - In one embodiment, an optical directional coupler includes an input terminal configured to receive an input optical signal and a first coupler optically coupled to the input terminal, where the first coupler has a first coupling length, and where the first coupler is configured to couple a first portion of the input optical signal to a first optical leg and a second optical portion of the input optical signal to a second optical leg. The optical directional coupler also includes the first optical leg, where the first optical leg is configured to phase shift the first portion of the optical signal to produce a first phase shift signal and the second optical leg, where the second optical leg is configured to phase shift the second portion of the optical signal to produce a second phase shift signal, and where the first phase shift signal has a phase difference relative to the second phase shift signal. Additionally, the optical directional coupler includes a second coupler configured to receive the first phase shift signal and the second phase shift signal and to output a first output optical signal to a first output, where the second coupler has a second coupling length, where a crosstalk of the input optical signal to a second output is below −15 dB for both transverse electrical (TE) polarized light and transverse magnetic (TM) polarized over a wavelength range spanning 40 nm. | 12-04-2014 |
20140369680 | VARIABLE SPECTRAL EFFICIENCY OPTICAL MODULATION SCHEMES - A method of transmitting a data signal using an optical transmitter of an optical communications system. A first encoder processes an N-bit input vector in accordance with a first mapping to generate a corresponding M-bit data stream. A Forward Error Correction encoder processes the M-bit data stream in accordance with a predetermined FEC encoding scheme to generate an encoded signal. A constellation mapper maps the encoded signal to symbol values in accordance with a predetermined modulation scheme to generate a corresponding symbol stream. A modulator modulates a carrier light in accordance with the encoded symbol stream to generate an optical signal for transmission through the optical communications system. The first mapping can be adjusted to maximize performance of the optical communications system. | 12-18-2014 |
20140369681 | Method And Apparatus For Alien Device Identification In Passive Optical Networks - A manner of detecting the presence of alien devices, for example ONUs, that are transmitting upstream in an optical access network such as a PON. An alien detection device, for example a properly configured OLT, supports normal network operation and also monitors a selected performance characteristic. When the selected performance characteristic is evaluated to perform within satisfactory parameters, a protocol that includes a command to subscriber devices such as ONUs to go quiet, for example a rogue check, is executed and a signal detector monitored during the quiet period. An alarm may be generated if an alien device appears to be present. | 12-18-2014 |
20150139639 | SCHEME OF REMOTE CONTROL OF THE SLICING LEVEL OF A RECEIVER IN A SMART TRANSCEIVER - A scheme is described of remote control of the slicing level of a receiver in a smart SFP (or SFP+, or XFP) duplex (or BiDi, or SWBiDi) transceiver in a communication system using an operating system with OAM and PP functions, an OAM, PP & Payload Processor, a transceiver, a BERT, and an optical link in the field. | 05-21-2015 |
20150311975 | FEEDBACK CONTROLLED RAMAN AMPLIFICATION IN OPTICAL SYSTEM - An optical communication link that includes two nodes interconnected by an optical channel that comprises optical fiber(s), and that is used to communicate an optical signal comprising multiple optical signal wavelengths. The first node provides an optical signal onto the optical channel towards the second node, or receives an optical signal from the optical channel from the second node. A Raman pump provides Raman pump power into the optical fiber of the optical channel to thereby perform Raman amplification of the optical signal in the optical fiber. The second node determines a quality measurement of at least of optical wavelength signals transmitted by the first node to the second node. The second node also transmits information from the quality measurement back to the first node. A controller at the first node controls at least one parameter of the Raman pump in response to this transmitted information. | 10-29-2015 |
20150341709 | METHODS AND APPARATUS FOR DETERMINING A PATH IN A COMMUNICATIONS NETWORK - A method for determining a path in an optical network, implemented by one or more controllers associated with a control layer, includes receiving a path request specifying start and end points, an associated bandwidth, and a longevity parameter providing an anticipated length during which the path is required; determining a route in the optical network through a routing algorithm executed by the controller, wherein the routing algorithm utilizes the start and end points, the associated bandwidth, and the longevity parameter to determine the path; and provisioning the path through a plurality of switches along the route. | 11-26-2015 |
20160056912 | METHOD AND DEVICE FOR DETERMINING WHETHER A CONFIGURATION OF AN OPTICAL TRANSMISSION INTERFACE HAS TO BE ADJUSTED AND THE CONFIGURING THEREOF - For determining whether a configuration of an optical transmission interface of a first device has to be adjusted for transmitting optical signals to a second device via an optical band-pass filter, the second device having an optical reception interface configured to enable receiving optical signals output by said optical band-pass filter and transmitted by the first device on a carrier wavelength when said carrier wavelength is comprised in the passband of the optical band-pass filter, said carrier wavelength and/or said passband of the optical band-pass filter being a priori unknown, a monitoring device performs: monitoring an evolution of a difference level between codewords received by the second device via said optical signals and corresponding codewords transmitted by the first device; and determining whether the configuration of the optical transmission interface of the first device has to be adjusted, on the basis of said monitoring. | 02-25-2016 |
20160080032 | METHOD AND ARRANGEMENT FOR SIGNAL TRANSMISSION AND COMPENSATION OF BACK REFLECTIONS IN OPTICAL ACCESS PON SYSTEMS - In a network terminal (ONU) of an optical network near end crosstalk (NEC) is compensated by a digital generated cancellation signal. To establish a connection with another terminal (OLT) signals avoiding NEC are transmitted and the compensation is performed while the power of the transmitted signal is increased in steps. | 03-17-2016 |
20160142154 | ITERATIVE POST-EQUALIZATION FOR COHERENT OPTICAL RECEIVERS - A post-equalization technique for recovering data bits from a coherent modulation optical signal is implemented in the digital domain by iteratively performing a decision-directed least mean square channel equalization step, a digital post filter step and a maximum likelihood sequence estimation step so that the symbol decisions of the previous iteration are fed to the decision directed least mean square channel equalization step to successively improve the symbol decisions. In an experimental setup, the iterative technique demonstrated performance improvement mitigating the bandwidth limitation as compared to a corresponding non-iterative technique. | 05-19-2016 |
20160173204 | OPTICAL SIGNAL RECOGNITION METHOD AND APPARATUS | 06-16-2016 |
20160182152 | BIT ERROR RATIO OPTIMIZATION METHOD AND APPARATUS | 06-23-2016 |
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