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Test signal

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398 - Optical communications


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Class / Patent application numberDescriptionNumber of patent applications / Date published
398016000 Test signal 89
20100092168OPTICAL COHERENT RECEIVER, APPARATUS FOR AND METHOD OF MONITORING PERFORMANCE THEREOF - The present invention relates to an optical coherent receiver and an apparatus for and a method of monitoring performance thereof. The apparatus for monitoring performance of the optical coherent receiver makes use of a first signal and a second signal from the optical coherent receiver to monitor performance of the optical coherent receiver, and comprises a first subtracter, for subtracting the second signal from the first signal to obtain a first subtraction result; a squarer, for obtaining a square of the first subtraction result; a delayer, for delaying the first subtraction result; a multiplier, for multiplying the first subtraction result with the delayed first subtraction result; and a second subtracter, for subtracting the result of the multiplier from the result of the squarer.04-15-2010
20090196600OPTICAL TRANSMISSION MODULE - Provided is an optical transmission module that includes: a semiconductor light emitting element for emitting laser light; a first driving unit for providing a first driving current to the semiconductor light emitting element; a switching unit connected between the semiconductor light emitting element and the first driving unit; and a package for accommodating the semiconductor light emitting element, the first driving unit, and the switching unit. The switching unit includes a first input for receiving a first driving current outputted from at least from the first driving unit, a second input for receiving a second driving current for testing the semiconductor light emitting element, and an output connected to the semiconductor light emitting element. The switching unit connects the first input or the second input to the output.08-06-2009
20090123147Test Instrument For Testing Multi-Wavelength Optical Networks Using Two Or More Tunable Lasers - The present invention relates to test equipment (e.g. TBERD 8000) with two or more Tunable Lasers (TL) for testing the complete spectrum of a DWDM system. Diagnostic software is used to stepwise tune a TL to a specific wavelength under test and simultaneously insert one or more distortion wavelengths while executing bit error and impairment tests on the wavelength under test. Information from these tests is correlated to create a combined DWDM network test report.05-14-2009
20130077961TECHNIQUES FOR GENERATING LOW RATE DATA PATTERNS COMPLIANT WITH PASSIVE OPTICAL NETWORKS - An apparatus for generating a reflection analysis data pattern (RADP) being utilized for performing a reflection analysis in a PON. The apparatus comprises a data pattern generator for generating a low rate data pattern using a low rate polynomial; a high rate adaptor for increasing a rate of the low rate data pattern to a transmission rate of the PON; first and second scrambler polynomial generators for generating first and second data sequences according to a scrambler polynomial of the PON; a pre-scrambler for scrambling a high-rate data pattern with the first data sequence; a scrambler coupled to the pre-scrambler for scrambling the output of the pre-scrambler with a time-shifted signal of the second data sequence to result with the RADP; and an encapsulator for encapsulating the reflection analysis data pattern output by the scrambler in a plurality of downstream frames transmitted from an OLT to ONUs of the PON.03-28-2013
20120207467Path Computation Element System and Method of Routing and Wavelength Assignment in a Wavelength Switched Optical Network - The disclosure includes an apparatus comprising a path computation element (PCE) that manages the processes of routing in an optical network, wherein the PCE receives a path computation request and provides a wavelength range to a network element (NE), and wherein the NE assigns a wavelength from the wavelength range. Also disclosed is an apparatus comprising a path computation client (PCC) that sends a path computation request to a path computation client (PCE) using path computation element communication protocol (PCEP), and receives a routing and wavelength assignment (RWA) reply to the path computation request using PCEP, wherein the RWA reply comprises an PCEP error message comprising a PCEP error object and an error value to indicate errors associated with the RWA request.08-16-2012
20130039646Optical Monitoring in a Communications Network Element - A communications network element comprises an input to receive an input optical signal having an input spectral property and carrying input traffic, an output and a monitoring port. Optical signal processing apparatus to receive the input signal and to form an output optical signal having an output spectral property and carrying output traffic. An optical splitter to tap off a part of one of the input signal and the output signal to form a tapped signal having a respective one of the input spectral property and input traffic, and the output spectral property and output traffic. Optical signal transforming apparatus to receive the tapped signal and to apply an optical transfer function (OTF) to it to form an optical monitoring signal, and to provide the monitoring signal to the monitoring port. The OTF preserves the spectral property of the tapped signal and applies a time-domain obfuscation to the tapped signal.02-14-2013
20100098409COMMUNICATION PATH SETTING METHOD, COMMUNICATION SYSTEM, OPTICAL PROPAGATION APPARATUS AND OPTICAL TRANSMISSION/RECEPTION DEVICE - An optical propagation apparatus and method setting a communication path to propagate a signal light between optical transmission/reception devices in different optical propagation apparatuses through a propagation path for multiplex communication. The optical propagation apparatus includes a conduction confirmation unit to confirm the conduction of the conduction confirming light output from one of the optical transmission/reception devices, and a setting unit to set, as a part of the communication path, the propagation path of the conduction confirming light following a point where the conduction of the conduction confirming light is confirmed by the conduction confirmation unit.04-22-2010
20130051790COHERENT OPTICAL RECEIVER, APPARATUS AND METHOD FOR DETECTING INTERCHANNEL SKEW IN COHERENT OPTICAL RECEIVER - In a coherent optical receiver, sufficient demodulation becomes impossible and consequently receiving performance deteriorates if an interchannel skew arises, therefore, a coherent optical receiver according to an exemplary aspect of the invention includes a local light source; a 90-degree hybrid circuit; an optoelectronic converter; an analog-to-digital converter; and a digital signal processing unit, wherein the 90-degree hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs a plurality of optical signals separated into a plurality of signal components; the optoelectronic converter detects the optical signals and outputs detected electrical signals; the analog-to-digital converter quantizes the detected electrical signals and outputs quantized signals; and the digital signal processing unit includes a skew compensation unit for compensating a difference in propagation delay between the plurality of signal components, and a demodulation unit for demodulating the quantized signals.02-28-2013
20130051789Monitoring Circuitry For Optical Transceivers - Monitoring signals associated with operating parameters of an optical transceiver are ascertained by using a comparator arrangement external to a micro-controller unit. Monitoring signals associated with these operating parameter are provided as inputs to a discrete arrangement of comparators and then evaluated against a known reference voltage source. The reference source is swept across a known range of values, and when the output of the comparator changes state, the value of the reference input associated with this transition is defined as the value of the specific monitoring input signal and stored within the proper memory location within the microcontroller portion of the transceiver monitor circuit. The digital output signal of the comparator is applied as an input to the microcontroller, which recognizes this digital signal as defining the specific value of the reference signal to use and equate with the value of the monitored signal.02-28-2013
20130051788PATH DISCOVERY IN A COMMUNICATIONS NETWORK - The invention relates to discovering a path in a communications network. Embodiments of the invention disclose determining whether at least two server trail termination points (TTPs) of the path are compatible, creating a server trail between the at least two TTPs, determining whether each TTP is framed by a respective client connection termination point (CCTP) of a higher layer, assigning a respective CCTP to each of the two TTPs, creating a link connection between the respective CCTPs, determining if one of the respective CCTPs is associated with a higher layer TTP, and if it is not so associated then determining if one of the respective CCTPs is constrained to a single TTP. The embodiments of the invention allow paths in a network to be determined after a change has taken place or a physical link has been created.02-28-2013
20100272431IN-SERVICE OPTICAL NETWORK TESTING - A system may include a first measurement device configured to be coupled to a first node in an optical path being measured. The first measurement device may be configured to generate a signal at an initiating device; identify an unused channel in an optical path, wherein the optical path includes at least two spans; and transmit the signal on the unused channel. A second test device may be configured to be coupled to a last node in the optical path being measured. The second measurement device may be configured to: receive the signal at a destination device; compensate the signal for chromatic dispersion (CD) and/or polarization mode dispersion (PMD) effects; and determine CD and/or PMD measurements associated with the optical path being measured based on the compensation.10-28-2010
20110013904PASSIVE OPTICAL NETWORK (PON) IN-BAND OPTICAL TIME DOMAIN REFLECTOMETER (OTDR) - An in-band OTDR uses a network's communication protocols to perform OTDR testing on a link. Because the OTDR signal (probe pulse) is handled like a data signal, the time required for OTDR testing is typically about the same as the time required for other global network events, and is not considered an interruption of service to users. A network equipment includes an optical time domain reflectometry (OTDR) transmitter and receiver, each operationally connected to a link to transmit and receive, respectively, an OTDR signal. When an OTDR is to be performed, a network device operationally connected to the link actuates the OTDR transmitter to transmit the OTDR signal on the link during a determined test time based on a communications protocol of the link, during which data signals are not transmitted to the network equipment. A processing system processes the OTDR signal to provide OTDR test results.01-20-2011
20120224847Quadrature Time Skew Detection for Coherent Optical Signals - A method for detecting and measuring time skew in high-speed DP-QPSK coherent optical receivers is described.09-06-2012
20090304379OPTICAL SIGNAL BIT RATE ADJUSTER, AN OPTICAL SIGNAL GENERATOR, AN OPTICAL TEST DEVICE, AN OPTICAL SIGNAL BIT RATE ADJUSTMENT METHOD, A PROGRAM, AND A RECORDING MEDIUM - An optical signal bit rate adjustment device of the present invention includes a demultiplexing unit that demultiplexes light into first demultiplexed light and second demultiplexed light, a first optical path through which the first demultiplexed light passes, a second optical path through which the second demultiplexed light passes, a multiplexing unit that multiplexes the first demultiplexed light having passed the first optical path and the second demultiplexed light having passed the second optical path, multiple first period changing units that are disposed along the first optical path, and change a period for which the first demultiplexed light passes through the first optical path according to first electric pulse signals to be fed, and multiple second period changing units that are disposed along the second optical path, and change a period for which the second demultiplexed light passes through the second optical path according to second electric pulse signals to be fed, where the first electric pulse signals and the second electric pulse signals are displaced in timing.12-10-2009
20090238558STATION TERMINAL DEVICE, COMMUNICATION SYSTEM, SUBSCRIBER DEVICE MANAGEMENT METHOD, AND RECORDING MEDIUM RECORDING PROGRAM FOR STATION TERMINAL DEVICE - In a conventional art, ONUs in services are significantly affected even when just one ONU is activated, and thus a communication bandwidth fails to be effectively utilized. To address this, an OLT includes a first distance information storing unit that stores information on the distance to an ONU in association with identification information which identifies the ONU (ONUi), and by using the distance information stored in the first distance information storing unit, an activation control unit controls activation of the ONUi.09-24-2009
20090238557Self-Calibrating Integrated Photonic Circuit and Method of Control Thereof - A self-calibrating integrated photonic circuit and a method of controlling the same. In one embodiment, the circuit includes: (1) a substrate, (2) a laser located on the substrate and configured to produce source light at an output frequency, (3) a laser alignment sensor located on the substrate and including: (3a) a reference optical resonator configured to receive the source light, have a null proximate a predetermined center frequency and provide output light as a function of a relationship between the output frequency and the center frequency and (3b) a photodetector configured to provide an electrical signal of a magnitude that is based on the output light and (4) a calibration controller located on the substrate, coupled to the photodetector and configured to adjust the output frequency based on the magnitude.09-24-2009
20120237202COHERENT OPTICAL RECEIVER, APPARATUS AND METHOD FOR DETECTING INTER-CHANNEL SKEW IN COHERENT OPTICAL RECEIVER - In a coherent optical receiver, sufficient demodulation becomes impossible and consequently receiving performance deteriorates if an inter-channel skew arises, therefore, a coherent optical receiver according to an exemplary aspect of the invention includes a local light source, a 90° hybrid circuit, an optoelectronic converter, an analog to digital converter, and a digital signal processing unit; wherein the 90° hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs a plurality of optical signals separated into a plurality of signal components; the optoelectronic converter detects the optical signals and outputs detected electrical signals; the analog to digital converter quantizes the detected electrical signals and outputs quantized signals; the digital signal processing unit includes a skew compensation unit for compensating a difference in propagation delay between the plurality of signal components, and an FFT operation unit for performing a fast Fourier transform process on the quantized signals; and wherein the difference in propagation delay is calculated on the basis of a plurality of peak values with a central focus on one peak value in the results of performing the fast Fourier transform process.09-20-2012
20100266275Optical Network Testing - A method includes generating a test signal and modulating the test signal. The method may also include transmitting the test signal on an optical path, where the optical path may include a number of add-drop multiplexer devices and amplifiers. The method may also include receiving the test signal at a destination device and converting the received test signal into an electrical signal. The method may further include identifying a portion of the electrical signal that is associated with the modulated test signal.10-21-2010
20100215357Optical Sampling With Coherent Detection - An optical sampling arrangement for high-speed measurement of the time-varying electric field of a data-carrying optical input signal. The present invention includes optical sampling of the optical input signal, followed by coherent mixing with a reference laser source in an optical hybrid solution. The generated streams of mixed optical samples are then detected and signal processed in order to reconstruct a sampled version of the electric field of the data-carrying optical input signal.08-26-2010
20090169202Link Discovery and Verification Using Loss of Light - Systems and methods for link discovery and verification that minimize the need for line termination resources to generate and interpret packets. According to one aspect of the present invention, a method for operating a first node in a data communication network to verify connectivity to a second node includes sending a request for verification of connectivity to the second node that identifies an IP address of the first node, a port of the first node, and an IP address of the second node. The method also includes toggling a signal emitted by the port, and notifying the second node of a toggling mode of the port. Finally, the method includes receiving a first message from the second node indicating whether the second node detected the toggling. The request for verification of connectivity is sent on a control channel via a control message separate from the signal and the first message.07-02-2009
20090060495INITIATING DIAGNOSTICS FROM ANY USER COMMUNICATION TERMINAL - A method for initiating diagnostic operations for a communication network, and devices, a network, and computer-readable storage medium storing control logic, that operate in accordance with the method. A test set device is communicatively coupled to a test head. The test set device provides access information to the test head, the access information comprising a diagnostic code indicating a diagnostic operation to be performed. The test head is communicatively coupled to a network. The test head provides the diagnostic code to the network device and sends a response from the network device to the test set device, the response indicating a result of performing the diagnostic operation. In this manner, a field technician can initiate diagnostics without the intervention of another technician, thereby reducing manpower required to troubleshoot a problem and improve troubleshooting turnaround.03-05-2009
20100098410METHOD AND APPARATUS FOR AUTOMATIC PORT INTERCONNECTION DISCOVERY IN AN OPTICAL NETWORK - To automatically discover the port connections for all nodes in a network, a master node generates a predetermined optical signal and transmits the predetermined optical signal to a neighboring node, which signal identifies the port on which the master node transmitted the predetermined signal. The recipient transmits a reply signal to the predecessor node and to the master node via a control channel, which identifies a port on which the predetermined optical signal was received by the neighboring node. By successively repeating this process in a methodical manner, the master node can discover all of the port interconnections in the optical network. Also each node can discover all its port interconnections to its neighbors. Moreover, by selecting controlling the state (e.g., terminate, open) of the ports of the non-master nodes in the network, the master node can control which nodes receive the predetermined signal, thereby ensuring proper port discovery.04-22-2010
20090047013In-Band Optical Frequency Division Reflectometry - An apparatus comprising an optical transmitter coupled to an optical fiber, and an optical receiver coupled to the optical fiber, wherein the transmitter is configured to transmit a test signal data pattern and user data into the optical fiber, and wherein the receiver is configured to receive a reflection of the test signal data pattern. Also disclosed is a network component comprising a processor configured to implement a method comprising promoting the transmission of an optical test signal data pattern into an optical fiber, wherein the test signal data pattern creates a radio frequency (RF) tone, and detecting a reflection of the RF tone in the optical fiber.02-19-2009
20090297140MEASURING CHROMATIC DISPERSION IN AN OPTICAL WAVELENGTH CHANNEL OF AN OPTICAL FIBER LINK - Two intensity modulated test signals are generated with precise frequency offset from a single laser source, and multiplexed into a combined test signal. The two modulated signals are demultiplexed at a receiver using a fixed periodic optical filter with complementary output ports. Group velocity dispersion/chromatic dispersion is measured over a large dynamic range, using pseudo-random intensity modulation and digital demodulation techniques.12-03-2009
20090290868METHOD, APPARATUS, AND SYSTEM FOR TRANSMITTING TEST DATA - A method for transmitting test data includes: an optical network unit (ONU) determining whether its current situation satisfies a preset condition, and if so, the ONU transmitting its test data to an optical line terminal (OLT). A method for acquiring a test data, an ONU, an OLT, and a passive optical network (PON) system are also provided. According to the method for transmitting test data, the method for acquiring test data, the ONU, the OLT, and the PON system provided by the present invention, the ONU may transmit its test data in real time, and the OLT may also obtain the ONU test data in real time, which helps to the real-time monitoring on the network status of the PON.11-26-2009
20110200324METHOD AND SYSTEM FOR OPTICAL CONNECTION VALIDATION - An optical add/drop multiplexer (OADM) having an Add path for adding optical channel signals input through a plurality of Add ports to an outbound dense wavelength division multiplexed (DWDM) signal, and a Drop path for switching selected channels from an inbound DWDM signal to one or more of a plurality of Drop ports. The OADM has a loopback connection between the Add path and the Drop path. The loopback connection couples a selected loopback channel wavelength from the Add path to the Drop path. The physical connection between a transceiver and the OADM can be verified by connecting the transmitter to an Add port of the OADM and the receiver to a Drop port of the OADM. The OADM is controlled to switch the selected loopback channel wavelength in the Drop path to at least one intended drop port to which the receiver should be connected, and the transmitter is controlled to transmit a predetermined test signal using the loopback channel wavelength. Detecting the test signal by the receiver verifies that the receiver is connected to the at least one intended drop port.08-18-2011
20100098408DETECTION OF CHANGES IN AN INTERVAL OF TIME BETWEEN OPTICAL OR ELECTRICAL SIGNALS - A method is disclosed for detecting changes in an interval of time (ΔT) between an optical or electrical signal and an optical or electrical reference signal using a photodetector. The method may be used to synchronize an optical or electrical signal with an optical or electrical reference signal. An apparatus for carrying out the method is also disclosed. The method comprises the steps of: receiving the optical signal and the optical reference signal by means of the photodetector, outputting an electrical response signal at an output of the photodetector, the electrical response signal having a frequency spectrum which depends on the interval of time (ΔT), filtering a selected harmonic from the frequency spectrum of the electrical response signal which has been output, and detecting changes in the interval of time (ΔT) from changes in the amplitude of the selected harmonic.04-22-2010
20080219660Communicating Information - The present invention relates to the communication of information where the information is introduced at a plurality of spaced apart locations onto an optical waveguide. The following steps are performed: (i) transmitting test signals onto the waveguide, components of the test signals being returned in a distributed manner along the waveguide; (ii) receiving first component signals returned from beyond a first location at which information is introduced; (iii) receiving second component signals returned from beyond a second location at which information is introduced, the second component signals being returned through the first location; and, (iv) processing the second component signals using the first component signals to distinguish information introduced at the second location from information introduced at the first location.09-11-2008
20090097844SENSING A DISTURBANCE - The present invention relates to a method of sensing a disturbance along an optical link including the steps of: using a first interferometer arrangement connected to an optical source so as to generate pairs of signal copies, which signal copies of a given pair are temporally delayed relative to one another; transmitting the time-displaced signal copies from the first interferometer arrangement onto the optical link; receiving the time-displaced signal copies transmitted over the optical link; and, using a second interferometer arrangement to temporally recombine the received signal copies from a given pair so as to generate an interferometer signal, which interferometer signal is representative of environmental effects on the optical link.04-16-2009
20090028550System and Method Using Differential Loop Gain for Fault Identification in Line Monitoring Equipment - A system and method using differential loop gain for fault analysis in line monitoring equipment. Differential loop gain data is calculated from loop gain data, and fault analysis is conducted using differential loop gain data, e.g. by comparing the differential loop gain data to predefined fault signatures.01-29-2009
20110206367SWITCHABLE FIBER TERMINATION - An apparatus, system and method are provided for a switchable fiber termination (SFT) incorporated into an optical network device that responds to a test signal received via an optical network carrying data. The test signal may be a part of a multiplexed signal carrying data and is separated from the data by a wavelength division multiplexer. The SFT may be used to determine the characteristics of an optical network, including the operational status of optical network devices.08-25-2011
20110268438UNIDIRECTIONAL ABSOLUTE OPTICAL ATTENUATION MEASUREMENT WITH OTDR - Devices and methods for optical measurements in point-to-point and point-to-multipoint networks, e.g. like PON networks with splitters are described in which reflected power from some known reflections at the end of the lines is used to determine the attenuation and stability of the attenuation of each line. Also a reference reflection is used at the beginning of the network so that an absolute loss measurement between the points of reflection and the reference reflection can be made. In a further aspect wavelength selective stable reflections and reflectors are used, to provide reflections in a wavelength range that does not interfere with normal operation.11-03-2011
20090080881OPTICAL COMMUNICATION METHOD, OPTICAL COMMUNICATION DEVICE, AND OPTICAL COMMUNICATION SYSTEM - The present invention relates to controlling wavelength switching in a plurality of nodes that are provided to increase the distance of signal transmission in inverse MUX transmission in which a high-speed line is divided into a plurality of low-speed lines for transmission. A maximum skew occurring between adjacent nodes is measured, and switching of wavelength channels is performed in one or a plurality of nodes on the basis of the measured maximum skew to keep the skew of the entire inverse MUX transmission system at or below a prescribed value. The optical communication device is provided with an NNI functional block to which high-speed lines on the transmission channel side are connected, and a UNI functional block to which low-speed lines on the client side are connected.03-26-2009
20110142440MEASUREMENT OF POLARIZATION MODE DISPERSION OR DIFFERENTIAL GROUP DELAY OF AN OPTICAL PATH - A method may include generating first and second optical signals and modulating the first and second optical signals simultaneously to synchronize the signals. The method may include varying the polarization of the second optical signal and transmitting the first and second optical signals. The method may include receiving the first and second optical signals, wherein the signals traveled along a same optical path. The method may include determining a plurality of differential travel delays between the first and second optical signals over a period of varying polarizations and determining a differential group delay based on the maximum and the minimum differential travel delays.06-16-2011
20090097843Optical Phase Modulator With Monitoring Structure - The invention relates to an optical waveguide device that includes a waveguide phase modulator (WPM). A waveguide monitoring structure is coupled optically in parallel with the WPM so as to form a Mach-Zehnder interferometer therewith for producing monitor light indicative of a phase shift imparted by the WPM. The waveguide monitoring structure includes a first optical tap for tapping off a fraction of light entering the first WPM for providing first tapped-off light, a second optical tap for tapping off a fraction of light exiting the first WPM for providing second tapped off light, and an ancillary phase modulator for modulating the optical phase of the first or second tapped-off light so as to modulate the intensity of the monitor light in dependence upon the first phase shift. A feedback circuit controls the phase shift imparted by the WPM based on a modulation index of the monitor light.04-16-2009
20090208202METHOD AND DEVICE FOR COMPLEX ANALYSIS OF OPTICAL SPECTRUMS - This invention relates to a device and associated process capable of obtaining the optical spectrum phase of an optical signal or test signal to be analyzed using techniques for heterodyning between two monochromatic spectral components simultaneously extracted from the test signal itself by means of stimulated Brillouin scattering.08-20-2009
20090208203METHODS OF RESTORATION IN AN ULTRA-LONG HAUL OPTICAL NETWORK - A method includes receiving a restoration indicator associated with a path that includes an optical cross-connect (OXC). The OXC is reconfigured from a standby configuration to a restoration configuration in response to the restoration indicator. An optical signal received in a first direction at a first wavelength is optically regenerated to produce an optical signal in the first direction at a second wavelength. An optical signal received in a second direction at the second wavelength is optically regenerated to produce an optical signal in the second direction at the first wavelength.08-20-2009
20110142439HIGH SPEED IN-SERVICE OPTICAL NETWORK TESTING - A method may include generating a signal at an initiating device. A channel in an optical path may be identified, with the optical path including at least two spans. Simulated polarization mode dispersion (PMD) is injected into the signal to generate a test signal. The test signal is transmitted on the channel and received at a destination device. PMD effects in the test signal are compensated, and a measurement of PMD for the test signal is determined based on the compensation, the PMD for the test signal including PMD for the channel and the injected PMD. A measurement of the PMD for the channel is determined based on the PMD for the test signal and the injected PMD.06-16-2011
20090252491SENSING A DISTURBANCE - The present invention relates to a system for sensing of a disturbance on an optical link. Data traffic from an optical source with a short coherence length is transmitted along the link to a receiver station on one or more of a plurality of time-division-multiplexed channels. One of the channels is used to transmit encoded phase information relating to the phase characteristics of the optical source output. At the receiver station the actual phase characteristics of the arriving light from the optical source is compared with the encoded phase information. Since a physical disturbance of the link is likely to alter the actual phase characteristics of the arriving light but not the encoded phase information, it is possible to determine if a physical disturbance has occurred. The system can conveniently be used to monitor an optical link carrying communications traffic.10-08-2009
20090263123FIBER NETWORK MONITORING - This specification describes technologies relating to optical fiber network monitoring. A monitoring system is provided. The monitoring system includes a fiber network including a plurality of branch fibers and a main station coupled to a main fiber of the fiber network to broadcast communications signals to a plurality of branch stations. The monitoring system includes a monitoring device configured to transmit a monitoring signal and detect reflected portions of the monitoring signal such that the received portions specifically identify a condition of specific branch fibers of the plurality of branch fibers and a plurality of filtering devices coupled to each respective branch fiber, each filtering device including a transmission window configured to pass a plurality of communication wavelengths and a distinct wavelength of the monitoring signal, where the distinct wavelength is not within the transmission window, and block the remaining wavelengths, where the distinct wavelength identifies the respective branch fiber.10-22-2009
20100183296Systems 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.07-22-2010
20110236014OPTICAL-TRANSMISSION-LINE INSPECTION APPARATUS, OPTICAL TRANSMISSION SYSTEM, AND OPTICAL-TRANSMISSION-LINE INSPECTION METHOD - An apparatus includes a pulse generator configured to generate a wavelet pulse defined by a setting device, an optical modulator configured to output an optical wavelet pulse based on the wavelet pulse generated by the pulse generator to an optical transmission line, and an analyzer configured to analyze a reflected wavelet pulse from the optical transmission line.09-29-2011
20100183297OPTICAL FIBER SENSOR HAVING ELECTRICAL CONNECTORS - An optical fiber sensor has a sensor band of optical sensor fibers. The band is connected on both ends to a transmitter unit and a receiver unit, the transmitter unit feeding optical signals into the optical fibers, the signals being optically evaluated with regard to the intensity thereof by the receiver unit. Parallel electrical conductors are located in the sensor band and can, for example, be designed as ribbon cables. The electrical conductors allow an additional electrical connection of the transmitter unit and the receiver unit, so that external cables advantageously need only be connected to one of the two units. The difficulty of connection is thereby reduced, and the wearing comfort is increased for the application of the fiber sensor, for example, as a back sensor.07-22-2010
20110129213METHOD AND APPARATUS FOR MEASURING A FACTOR CHARACTERIZING A BALANCED DETECTION DEVICE - A method is provided for measuring a factor, called herein the single-port rejection ratio (SPRR), characterizing a balanced detection device. The SPRR is representative of the ratio of the weak differential output current measured under illumination of a single-port of the balanced detection device to the strong measurable differential output current obtained under dual-port illumination. An apparatus for measuring the SPRR is also provided.06-02-2011
20090110390Multimode Fiber Link Probe - A link probe for multimode fibers in optical networks is provided. An optical test probe signal is sent over a multimode fiber of an optical network link and a receiver converts the optical signal into an electronic signal with a trigger generated by the clock recovery section of an EDC (electronic dispersion compensation) unit. The digital signal is processed by a modified IEEE algorithm to determine a TWDP (Transmitter and Waveform Dispersion Penalty) parameter which quantifies the transmission quality of the multimode fiber and link suitability to LRM transmission.04-30-2009
20110236015METHOD OF SWITCHING OPTICAL PATH, AND APPARATUS THEREOF - Terminals of upstream and downstream sides of an in-service line and a detour line are connected by optical couplers. An optical oscilloscope is connected to one optical coupler, and a chirped pulse light source is connected to the other optical coupler to thereby form dualized lines. The detour line includes an optical line length adjuster for compensating for the phase difference of optical transmission signals that occurs because of the optical line length difference with the in-service line. Pulse light in which an optical frequency is chirped is transmitted from the chirped pulse light source. The pulse light is branched by the second optical coupler, passes through the in-service line and the detour line, is multiplexed again by the first optical coupler, and is measured by the optical oscilloscope. While matching an arrival time of the pulse light, the optical line length is adjusted by the optical line length adjuster so as to minimize the size of upper and lower limits of an interference waveform generated in an upper part of the pulse light waveform or so as to make a frequency of an interference waveform become zero.09-29-2011
20120243864OPTICAL COMMUNICATION DEVICE AND OPTICAL COMMUNICATION METHOD - An optical communication device includes an optical switch that switches a path of an optical signal; a first path that transmits an optical signal between a first communication unit and the optical switch; a second path that transmits an optical signal between a second communication unit and the optical switch; and a switch controller that controls the optical switch. After an optical connection between the first communication unit and the optical switch and an optical connection between the second communication unit and the optical switch are checked, the switch controller switches the path of the optical signal selected by the optical switch to enable optical communication between the first communication unit and the second communication unit.09-27-2012
20090028549System and Method for Suppressing Beat Noise in Line Monitoring Equipment - A system and method for suppressing beat noise in line monitoring equipment. A wavelength dither generator wavelength modulates a carrier wavelength of a test signal laser transmitter. A test code is modulated on the dithered carrier wavelength to provide a test signal output of the line monitoring equipment.01-29-2009
20120121251MONITORING AND CONTROL OF ELECTRONIC DEVICES - A method, a system, and a computer program product for managing one or more electronic devices. Performance of an electronic device is monitored and presented to a user through a digital agent interface. The performance of the electronic device is controlled automatically by digital agent through the digital agent interface. The invention also enables automatic testing of the electronic device through the digital agent interface by setting up test configurations, activating test signals, and interpreting any error codes that may be generated.05-17-2012
20100086298ENFORCED ROUTING IN SWITCHED NETWORK FOR FRU VERIFICATION - A method implemented in a computer infrastructure having computer executable code having programming instructions tangibly embodied on a computer readable medium. The programming instructions are operable to configure an initiator-to-initiator message route in a switched fibre channel arbitrated loop (FCAL) network such that the initiator-to-initiator message route traverses a replacement field replaceable unit (FRU). Additionally, the programming instructions are operable to transmit a verification initiator-to-initiator message along the initiator-to-initiator message route to verify proper operation of the replacement FRU.04-08-2010
20080205884Polarization Controlled Interferometric Chirp Characterization - The invention relates to determining a chirp property) of an optical device, comprising: receiving an input optical signal from the optical device and generating an output optical signal by providing a change of a state of polarization by means of a polarization controller operating at a first setting and an interferometric superposition of two signal parts in any order, determining an optical intensity of the output optical signal, controlling the polarization controller to operate at a second setting in order to provide a different change of the state of polarization and repeating previous steps for determining a corresponding optical intensity, and determining the chirp property by evaluating the optical intensities determined in response to the different polarization controller settings.08-28-2008
20080205883Device For Measuring the Profile of Very Short Single Pulses - The invention relates to a device for measuring the profile of single optical pulses, comprising:08-28-2008
20110255861Method and Apparatus for Determining a Signal Transfer Characteristic Along a Light Path in an Optical Network - There is provided a method for determining a signal transfer characteristic along a light path between a first point and a second point in an optical network. The optical network comprises at least one optical element situated in the light path. The method comprises transmitting a plurality of optical test signals of different bandwidths from the first point along the light path. Each signal has a known bandwidth and a known power. The method further comprises receiving the optical test signals at the second point after they have travelled along the light path and measuring the power of each received optical test signal. The method also comprises determining the signal transfer characteristic along the light path from the power measurements.10-20-2011
20110019994High Bandwidth Demodulator System And Method - A method of analysing an input signal, the method including the steps of: (a) dividing a first input signal into first and second orthogonal signal polarisation components; (b) dividing a second input signal into orthogonal first and second orthogonal local polarisation components; (c) mixing the first orthogonal signal component with the second orthogonal local polarisation component to provide a first mixed signal; (d) mixing the second orthogonal signal component with the first orthogonal local polarisation component to provide a second mixed signal; (e) analysing the first and second mixed signal to determine the polarisation or phase information in the input signal.01-27-2011
20100183295ROGUE ONU DETECTION VIA PHOTONIC MIXING - A system, method, and computer readable medium for rogue Optical Network Unit (ONU) detection via photonic mixing, comprises a first Wavelength Division Multiplexer (WDM), a second WDM communicably coupled to the first WDM, a non-linear medium communicably coupled to the second WDM, and a photodetector communicably coupled to the non-linear medium, wherein the first WDM transmits a first upstream beam and a second upstream beam to the second WDM, wherein the first upstream beam is a normal upstream beam and wherein the second upstream beam is a rogue upstream beam, wherein the second WDM transmits the normal upstream beam and the rogue upstream beam to the non-linear medium, wherein the non-linear medium mixes the normal upstream beam and the rogue upstream beam resulting in a mixed beam, wherein the non-linear medium transmits the mixed beam to the photodetector, and wherein the photodetector analyzes the mixed beam to indicate the presence of a rogue ONU.07-22-2010
20130294763Optical Signal Power Selection and Control11-07-2013
20100014854TESTING AN OPTICAL NETWORK - The present invention relates to testing a passive optical network having a head end and a plurality of terminals, which terminals are connected to the network at a respective plug and socket arrangement located at customer premises. A test device is provided having a standard plug for connection in place of a terminal in the socket of the relevant customer premises. An identification device is provided in the socket. The test device is arranged to (i) read the identity of the identification device and (ii) test the line and transmit a result to the head end together with the identity so that the line to the customer premises can be tested remotely. When the line has been tested, the test device can be removed. Because the test device uses an existing connection, the optical (insertion) loss is reduced.01-21-2010
20120057865COMMUNICATION SYSTEM AND TIME SYNCHRONIZATION METHOD - In a communication system using a PON, time synchronization of a slave device such as a base station is realized with respect to a master device such as an L2SW or the base station. Time information acquired by a GPS satellite is corrected by ranging information of a discovery function of an OLT so as to be reflected on time information of each ONU. A propagation delay from the L2SW to the OLT is obtained with the use of a delay estimation mechanism, a propagation delay from the OLT to the ONU which is obtained by ranging is added to obtain a propagation delay from the L2SW to the ONU. The obtained propagation delay from the L2SW to the ONU is added to the transmitted time stamp value whereby a time stamp value received at a base station or femtocell side becomes a time into which the propagation delay to the ONU is incorporated, and absolute values of clock timers can be synchronized with each other. The addition process can be realized by rewriting the time stamp value of the packet within the OLT or the ONU.03-08-2012
20120020659Polarization Monitoring in Polarization Division Multiplexing in Optical Communications - Systems and techniques for optical communications based on polarization division multiplexing are described.01-26-2012
20120301137ERRONEOUS OPTICAL FIBER CONNECTION DETECTING METHOD AND NODE DEVICE - A node device includes a data pattern generator configured to generate different fixed patterns for a plurality of ports to insert the generated fixed patterns into optical signals output from a plurality of optical transmitters, an optical switch configured to switch outgoing paths of the optical signals to output the optical signals as a multiplexed signal from one of the ports, a detector configured to detect a frequency spectrum of the multiplexed optical signal, and a management part configured to monitor a peak frequency of the detected frequency spectrum to detect an erroneous optical fiber connection associated with the optical transmitters based on peak frequencies corresponding to the different fixed patterns for the respective ports.11-29-2012
20120301136COHERENT POWER COMBINING FOR SIGNALS THROUGH MULTIPLE SATELLITE COMMUNICATIONS CHANNELS - A communication system and method that allows a transmitter segment (ground end of uplink segment) to dynamically combine power from a plurality of propagation channels (transponders) to improve power levels of signals being transmitted, without affecting the receiver segment (user end of downlink segment) and the propagation segment (space segment), and without modifying propagation apparatus configurations (satellite). Specifically, the transmitter segment generates mixtures of input signals by using Wavefront-Multiplexing and transmits wavefront-multiplexed (WFM) signals through propagation channels to a receiver segment that coherently separates the mixtures of received WFM signals by using adaptive equalization and Wavefront-De-Multiplexing. The WFM signal mixtures allow an operator, or automated system, at the transmitter segment to dynamically allocate equivalent channel (transponder) powers according to continuously changing market demands by dynamically including change of relative input powers into ratios of the WFM signal mixtures being transmitted.11-29-2012
20080298800TRANSMISSION DEVICE AND ROUTE VERIFYING METHOD - A transmission device transmitting a data frame to an opposite transmission device by use of one virtual transmission path built up by a plurality of communication channels comprises a route control unit determining each of routes of the communication channels building up the virtual transmission path between the transmission device and the opposite transmission device, a circuit setup unit performing a circuit setup of the self-device based on the routes determined by the route control unit, and a test signal transmitting unit transmitting test signals to the opposite transmission device via the communication channels based on the circuit setup.12-04-2008
20120251098Method, apparatus and system for high-speed transmission on fiber optic channel - Multi-carrier modulation fiber optic systems constructed using a series of electrical carriers, modulating the data on the electrical carriers and combining the carriers to form a wideband signal. The wideband signal can then be intensity modulated on a laser and coupled to a fiber optic channel. A receiver may then receive the laser signal from the fiber optic channel and convert it into an electrical signal. Multi-carrier modulation may be applied to existing fiber channels, which may be of lower quality. Existing fiber channels may have characteristics which prevent or restrict the transmission of data using intensity modulation at certain frequencies. An adaptive multi-carrier modulation transmitter may characterize an existing fiber optic channel and ascertain the overall characteristics of the channel. The transmitter and receiver can then be configured to use various bandwidths and various modulations in order to match the transfer characteristic of the fiber channel. A series of adaptive multi-carrier modulation transmitters and receivers can be integrated on a single integrated circuit. If multiple adaptive receivers and transmitters are integrated on a single integrated circuit, they may be used to upgrade existing networks by adding different wavelength lasers for the transmission of data in order to achieve any capacity desired. Each receiver and transmitter may characterize the fiber for its particular wavelength laser and may configure the modulation and bandpass to the fiber's characteristics.10-04-2012
20120251099Multiplexer Lane Alignment for High-Speed Data Systems - Patterns detected by a low-speed receiver at the output of a high-speed multiplexer are used to determine when multiplexer input lanes are deskewed.10-04-2012
20120155857METHOD, APPARATUS AND UNIT FOR DETECTING FAULT OF SUBMARINE DEVICE - The embodiments of the present invention relate to optical communication technologies, and provide a method, an apparatus, and a unit for detecting a fault of a submarine device. The apparatus includes: a pair of optical couplers that are respectively set on two optical cables for transmitting optical signals in opposite direction and are configured to receive or send optical detection signals through the optical cables, where: the two optical couplers are connected through an optical fiber that transmits an optical detection signal, and a photosensitive component is set on the optical fiber and is configured to adjust an optical parameter of the optical detection signal by perceiving change of an ambient environment state parameter when a fault occurs. The embodiments of the present invention bring benefits of detecting whether a target submarine device is faulty, and locating a cause for the fault of the submarine device accurately.06-21-2012
20110076011Apparatus for monitoring optical signal quality specifically applicable to NRZ optical signals - A binary intensity-modulated light signal to be monitored is split into three signal beams. The first and third beams are converted into electric signals. Frequencies of the first electric signal corresponding to a bit rate pass a filter bank. The intensity of the filtered signal is detected by an RF intensity detector. A delaying interferometer makes the second beam interfere with a light signal obtained by delaying the second beam by a predetermined delay time. One of the resulting interference signals is converted into an electric signal. The intensities of the amplified signal are detected by another RF intensity detector. The third electric signal is smoothed by the filter bank, and its average intensity is detected by a power detector. The intensities of the detected, amplified signals are found relative to the detected average intensity to determine wavelength dispersion and optical SNR or the tendency of their changes.03-31-2011
20120121252OPTICAL COMMUNICATION SYSTEM FOR SUPPORTING REMOTE OPERATION MANAGEMENT - Provided is an optical communication system including: a remote control device for generating OAM (Operation, Administration, and Maintenance) signal including OAM information for equipment, converting the OAM signals to OAM optical signals, overlaying the OAM optical signals and communication upstream signals transmitted to a Communication Stations device, and controlling the transmission of the overlaid signals to the Communication Stations device; and the Communication Stations device for generating OAM control signals, converting the OAM control signal to OAM optical control signals, overlaying the OAM optical control signals and optical communication downstream signals transmitted to the remote control device, and controlling the transmission of the overlaid control signals to the remote control device.05-17-2012
20120121250MEASURING DIFFERENTIAL GROUP DELAY IN AN OPTICAL FIBER - A system includes an optical transmitter configured to generate an optical signal that includes a scrambled polarization state; and output the optical signal via an optical fiber associated with a network path that is transporting network traffic. The system also includes an optical receiver configured to receive the optical signal; measure a polarization associated with the optical signal; determine, based on the polarization, a degree of polarization associated with the test signal; identify a differential group delay associated with the test signal based on the degree of polarization; output a notification that the optical fiber is available to carry high capacity traffic when the differential group delay is less than a threshold, where the high capacity traffic includes a data rate that his greater than another threshold; and output a notification that the optical fiber is not available to carry the high capacity traffic when the differential group delay is not less than the threshold.05-17-2012
20120163801OPTICAL FIBER COMMUNICATION SYSTEM - There is provided an optical fiber communication system restricting enlargement of the diameter of an optical fiber as well as enabling achievement of a large-capacity optical communication with a small number of optical fibers.06-28-2012
20120177364METHOD AND APPARATUS FOR AUTOMATIC DISCOVERY IN OPTICAL TRANSPORT NETWORKS - In order to improve the link adjacency discovery in an Optical Transport Network, a method and related network nodes are provided. A first network node (07-12-2012
20120177363OPTICAL SIGNAL OUTPUT APPARATUS, ELECTRICAL SIGNAL OUTPUT APPARATUS, AND TEST APPARATUS - To efficiently apply jitter to an optical signal using a simple configuration, provided is an optical signal output apparatus that outputs an optical pulse pattern signal including jitter, the optical signal generating apparatus comprising a light source section that outputs an optical signal having an optical frequency corresponding to a frequency control signal; an optical modulation section that modulates the optical signal output by the light source section, according to a designated pulse pattern; and an optical jitter generating section that delays an optical signal passed by the optical modulation section according to the optical frequency, to apply jitter to the optical signal.07-12-2012
20120230673MEASUREMENT OF ACCUMULATED CHROMATIC DISPERSION IN AN OPTICAL DATA TRANSMISSION NETWORK - A method of measuring accumulated chromatic dispersion in an optical data transmission network includes the following method steps: a) sending a first bit pattern with at least one first pulse at a first wavelength and a second bit pattern with at least one second pulse at a second wavelength over an optical fiber; b) receiving the first bit pattern and the second bit pattern; c) determining a relative temporal shift between the first bit pattern and the second bit pattern; and d) calculating the accumulated chromatic dispersion from the relative temporal shift.09-13-2012
20130302027OPTICAL MEASUREMENT METHOD AND SYSTEM - The present application is directed to the measurement of the intensity and phase of high speed optical signals. The present application uses a tunable optical local oscillator, an optical coupler, a photodiode and RF electronics. The tunable laser enables successive measurements to be taken across the optical spectrum allowing the system to measure extremely high bandwidth signals. The signal generated by the local oscillator comprises a component at a frequency between two adjacent modes of the periodic optical signal to be measured. The local oscillator and said periodic signal are optically mixed and sent to a photodiode, the measurement of the phase being based on isolating the resulting beat frequencies. This approach offers a significant improvement over existing time resolved approaches which are limited to the bandwidth of the photodiode (˜50 GHz).11-14-2013
20100202772Method and Device For Validating a Link Attribute In The Nodes Of Automatically Switched Optical Network - The invention provides a method and device for verify link attributes in a node of an Automatically Switched Optical Network. In the Automatically Switched Optical Network, the node and another node are connected to a first port and a second port of one bidirectional link respectively, and the bidirectional link is divided into a first unidirectional link from the first port to the second port and a second unidirectional link from the second port to the first port. The method comprising the steps of: configuring a plurality of link attributes of the first unidirectional link in the node; receiving in the node a plurality of link attributes of the second unidirectional link configured in the another node from the another node; and comparing in the node the plurality of link attributes of the first unidirectional link with the received plurality of link attributes of the second unidirectional link respectively to check whether they match each other.08-12-2010
20110158638PON SYSTEM AND REDUNDANCY METHOD - An optical line terminal performs transmission to optical network units using a light signal having a wavelength different for each of systems, allocates communication time to data, which is transmitted from the optical network units, in a time division manner for each of the systems, selects, for each of the optical network units, a system for performing data transmission, and transmits the data using a wavelength corresponding to the selected system. The optical network unit includes: ith blocking filter that removes a component other than a component in a predetermined wavelength band, which is set to correspond to an ith system, from a received light signal; and ith PON processing unit that applies termination processing to signals and transmitting the data based on an allocation result of the optical line terminal. The PON system includes n optical network units corresponding to i=1 to i=n.06-30-2011
20120243863Optical Transceiver Integrated with Optical Time Domain Reflectometer Monitoring - An optical transceiver having an integrated optical time domain reflectometer monitoring unit and methods for using the same are disclosed. The disclosure relates to an optical transceiver comprising an optical device comprising a wavelength division multiplexing system (WDM), a data signal driver, a data signal limiting amplifier, and an optical time domain reflectometer (OTDR) data processing module. Furthermore, the optical transceiver is particularly advantageous in an optical line terminal (OLT) and/or a passive optical network (PON). The integrated OTDR data processing module can protect the optical transceiver, ensure successful monitoring data, simplify network wiring and decrease system and network costs by decreasing the number of OTDR modules and WDM units.09-27-2012
20080226289Optical device testing - In one embodiment, an apparatus comprises a pattern generator to generate a test bit pattern in an electrical signal, an optical transponder to covert the electrical signal to an optical signal, transmit the optical signal to a device, and receive a processed test bit pattern from the device, and an error detector to analyze the processed test bit pattern to determine an error rate associated with the device.09-18-2008
20110274426DETECTING METHOD, APPARATUS, AND SYSTEM IN AN OPTICAL DISTRIBUTION NETWORK - A detecting method, an apparatus, and a system in an Optical Distribution Network (ODN) are provided. The method includes: an Optical Line Termination (OLT) reserves a test window, and an Optical Network Unit (ONU) stops sending an uplink signal in the test window, the OLT emits a downlink test signal having a wavelength the same as that of the uplink signal in the test window, the OLT receives backward signals of the downlink test signal, in which the backward signals include a backward scattered signal and a backward reflected signal, processes the backward signals, and obtains state information of the ODN according to the backward signals. The method does not need to add other hardware, and the downlink signal is sent normally in the downlink. The implementation is low in the cost and easy in the technology.11-10-2011
20130142506CLOSED LOOP OPTICAL MODULATION AMPLITUDE CONTROL - Systems and methods are provided for an optical modulation feedback circuit. The feedback circuit includes a low frequency comparison circuit configured to receive a monitoring signal generated by an optical detector, the monitoring signal being proportional to an amount of light generated by an optical transmission device that transmits based on a data signal that is received by an optical driver. The comparison circuit is further configured to generate a modulation control feedback signal that is transmitted to the optical driver based on a comparison of a low frequency component of the monitoring signal and a low frequency component of the data signal.06-06-2013
20130114955Method and System for Testing Jitter Compatibility - A method and system for testing jitter compatibility are disclosed in the present invention, which includes: an interconnection testing board configured with a non-NRZ optical transponder needing to satisfy the board jitter performance specification, and according to the specification, testing the jitter performance of the interconnection testing board to indirectly judge whether the jitter compatibility of non-NRZ optical transponder at a line side of the interconnection testing board is qualified, wherein: at the line side and a client side of the interconnection testing board, a non-NRZ optical transponder to be tested and an NRZ optical transponder with qualified jitter performance are configured respectively, and the jitter performance of interconnection testing board is tested; if the qualified jitter performance of interconnection testing board is obtained through testing, believing that the jitter compatibility of non-NRZ optical transponder to be tested is qualified.05-09-2013
20110268437BIT ERROR GENERATION SYSTEM FOR OPTICAL NETWORKS - A system may include an optical bit error generator comprising a high instantaneous power light source. An optical coupler may couple an output of the optical bit error generator to a traffic fiber. A device under test receives a traffic signal via the traffic fiber. A performance monitor is coupled to the device under test to determine responsiveness of the device under test to a bit error condition simulated by the optical bit error generator, wherein the high instantaneous power light source in the optical bit error generator is configured based on a protocol of a traffic signal in the traffic fiber and the bit error condition.11-03-2011
20130148959FIBER OPTIC TELECOMMUNICATIONS CARD WITH SECURITY DETECTION - A transceiver card for a telecommunications box for transmitting data over a first optical fiber and receiving data over a second optical fiber. The card has transmitter for transmitting data over the first optical fiber, the transmitter having a laser and a modulator, a fiber output optically connected to the laser for connecting the first optical fiber to the card, a fiber input for connecting the second optical fiber to the card, a receiver optically connected to the fiber input for receiving data from the second optical fiber, and an OTDR optically connected between the transmitter and the fiber output or between the receiver and the fiber input. An energy level detector is also provided between the receiver and the fiber input.06-13-2013
20120134665Testing of Transmitters for Communication Links by Software Simulation of Reference Channel and/or Reference Receiver - A transmitter for a communications link is tested by using a (software) simulation of a reference channel and/or a reference receiver to test the transmitter. In one embodiment for optical fiber communications links, a data test pattern is applied to the transmitter under test and the resulting optical output is captured, for example by a sampling oscilloscope. The captured waveform is subsequently processed by the software simulation, in order to simulate propagation of the optical signal through the reference channel and/or reference receiver. A performance metric for the transmitter is calculated based on the processed waveform.05-31-2012
20110293265Optical Access Network, Secondary Network Side Termination Node of an Optical Access Network, and Method for Operating a Network Side Termination Node - An optical access network has a first and a second network-side termination node, the first including a first transceiver arrangement connected to a first optical link, configured to send a first signal to a customer side termination node including a transceiver for receiving the first signal, and the second including a second transceiver arrangement connected to a second optical link and configured for sending a second signal to a transceiver of a customer-side termination node via the second link. The transceiver of the customer side termination node has a loopback element emitting a monitoring signal back to the network side termination nodes. Both network-side termination nodes have a link failure detector receiving the monitoring signal.12-01-2011
20120288274OPTICAL NETWORK SYSTEM AND DEVICES ENABLING DATA, DIAGNOSIS, AND MANAGEMENT COMMUNICATIONS - An optical transmitter module includes an optical transmitter configured to emit a first optical signal that includes a user data signal having a first frequency and comprising user data associated with the first communication channel. A management diagnostic modulator can superimpose a diagnostic waveform to the user data signal. The diagnostic waveform has a second frequency associated with the first communication channel, wherein the second frequency is in a frequency range between about 10 KHz and about 10 MHz. A management unit can modulate the diagnostic waveform by a management data signal at a third frequency associated with the first communication channel. The management data signal includes management data for digital diagnostic monitoring signals (DDM) and the control of the first optical transceiver module.11-15-2012
20130259470METHOD AND APPARATUS FOR TESTING OPTICAL FIBER AND PASSIVE OPTICAL NETWORK SYSTEM - A method for testing an optical fiber includes: receiving a test optical signal from an optical fiber network, and converting the test optical signal into a test current signal; receiving, by a transimpedance amplifier, the test current signal by using a first working mode and outputting a first test voltage signal; acquiring a swing of the first test voltage signal, and determining whether the swing of the first test voltage signal meets a preset condition; and receiving, by the transimpedance amplifier, the test current signal by using a second working mode and outputting a second test voltage signal when the swing of the first test voltage signal meets the preset condition, where an upper limit and a lower limit of a receiver dynamic range when the transimpedance amplifier works in the first working mode are different from those when the transimpedance amplifier works in the second working mode.10-03-2013
20130259469Apparatus And Method For Testing Fibers In A PON - A manner of providing for testing of access fibers in a PON (passive optical network) using OTDR (optical time-domain reflectometry). According to the invention, a PON includes an optical splitter module having one or more optical couplers that combines downstream light from 1×N optical splitter directing the output of an OLT (optical line terminal) and a cyclic AWG (arrayed waveguide grating) for transmission toward one or more ONUs (optical network units). The splitter module is preferably formed on a single semiconductor chip, such as a PIC (photonic integrated circuit) chip and may reside in an outside plant of the PON.10-03-2013
20130266307DIAGNOSTIC PORT FOR INTER-SWITCH AND NODE LINK TESTING IN ELECTRICAL, OPTICAL AND REMOTE LOOPBACK MODES - A diagnostic testing utility is used to perform single link diagnostics tests including an electrical loopback test, an optical loopback test, a link traffic test, and a link distance measurement test. To perform the diagnostic tests, two ports at each end of a link are identified and then statically configured by a user. The ports will be configured as D_Ports and as such will be isolated from the fabric with no data traffic flowing through them. This configuration can be static or can be on request or on errors. The ports will then be used to send test frames to perform the diagnostic tests. After completion of requested or on error testing the ports can return to normal operation.10-10-2013
20130266308COHERENT OPTICAL RECEIVER, DEVICE AND METHOD FOR DETECTING INTER-LANE SKEW IN COHERENT OPTICAL RECEIVER - The disclosed coherent optical receiver includes a local light source; a 90-degree hybrid circuit; an optoelectronic converter; an analog-to-digital converter; a skew addition unit; and a FFT operation unit. The 90-degree hybrid circuit makes multiplexed signal light interfere with local light from the local light source, and outputs multiple optical signals separated into a plurality of signal components. The optoelectronic converter detects the optical signal and outputs a detected electrical signal. The analog-to-digital converter digitizes the detected electrical signal and outputs a detected digital signal. The skew addition unit adds to the detected digital signal an additional skew amount whose absolute value is equal to, whose sign is opposite to a skew amount of a difference in propagation delay in each lane connected to each output channel of the 90-degree hybrid circuit. The FFT operation unit performs a fast Fourier transform on the output from the skew addition unit.10-10-2013

Patent applications in class Test signal