Abstract: A method, bus controller, and computer program product for arbitrating use of a communication bus for a certain one of a plurality of interconnected nodes that share the bus. The method includes the steps of: presenting a data frame on the transmitter and receiver side of the bus, where the certain node presents at the transmitter side, where the data frame has a embedded clock of a predetermined timing and a header field, synchronizing, by the certain node, with the embedded clock in the data frame at the receiving side of the bus, successively presenting, by the certain node, an idle pattern on the bus determined by a preassigned node ID, emitting light, by the certain node, on the bus at a predetermined timing preassigned to the certain node, and monitoring light emission on the bus that indicates a bus access request from another one of the nodes.

Abstract: A device may include a first module to capture information relating to network traffic passing through a first interface in a network device. A second module may capture information relating to network traffic passing through a second interface in the network device. A control module may be configured to transmit control commands to the first module and the second module, the control commands instructing the first module and the second module to capture information relating to network traffic passing through the first interface and the second interface, respectively. The control module may be further configured to receive the captured information from the first module and the second module, correlate the received information from the first module and the second module; and provide the correlated information to a user.

Abstract: A method includes outputting an optical signal from an optical transmitter; causing the optical signal to propagate through equipment of an optical communication site and to loop back to an optical receiver; measuring optical powers, respectively, based on taps proximate to the optical transmitter and the optical receiver; calculating an optical power loss based on the optical powers measured; determining whether the optical power loss is an acceptable value; and indicating when the optical power loss is not the acceptable value.

Abstract: A network monitoring module for deployment in a branched optical network at a split location where the network splits into a plurality of branches, the network monitoring module is disclosed, comprising an array of transmitters for generating optical test signals, an output of each transmitter in the array being optically connected to a respective branch, a detector for receiving a remotely generated optical trigger signal which identifies a particular one of the transmitters, and a CMOS circuit for selectively triggering the transmitter identified in the optical trigger signal to transmit an optical test signal into the branch connected to that transmitter.

Abstract: A device and method to allow to estimate drift induced by temperature variation in a network including a frequency splitter based on a Mac Zehnder, or alike component, and to track it over time, by adding mirrors to the unused port of the Mac Zehnder components. Doing so, both OLT and ONU are able to scan a band of frequencies. The frequency corresponding to the nominal wavelength of the component will be reflected on the other port on the same side of the Mac Zehnder while other frequencies will go through the Mac Zehnder to be reflected by the mirror and come back to the emitter.

Abstract: An optical receiver able to distinguish a failure occurred in one of multiplexed signals from a failure in the transmission medium is disclosed. The optical receiver includes an optical de-multiplexer, optical devices, a signal processor, and a controller. Each of the optical devices converts the de-multiplexed signal into an electrical signal. A clock is extracted from one of the electrical signals. The processor decides, based on the electrical signals and the clock, one of the multiplexed signals falls in a failure.

Abstract: A time-domain (TD) reflectometer that is designed to operate based on probe and response signals that are substantially fully spectrally confined to a designated frequency passband. In one embodiment, the TD reflectometer uses a passband transmitter to generate the probe signal based on a pseudo-random bit sequence and a passband receiver to demodulate the response signal. The TD reflectometer determines the impulse response of a channel under test based on cross-correlation of the transmitter and receiver baseband signals. In various embodiments, the TD reflectometer can be designed to operate in an acoustic-frequency range, a radio-frequency range, or an optical-frequency range. Due to its passband configuration, the TD reflectometer is advantageously capable of determining impulse responses without disrupting the operation and/or interfering with normal functions of the tested channel.

Abstract: An optical transmission apparatus includes an amplifier, a first output port to select a wavelength from the wavelength-division-multiplexed signal light amplified and output signal light with the selected wavelength to an operation line, a second output port to output multiplexed light obtained by multiplexing any one of first spontaneous emission light and second spontaneous emission light to a preliminary line, the first and the second spontaneous emission light being parts of spontaneous emission light generated by the amplifier, the first spontaneous emission light being in a wavelength range that is not selected, and the second spontaneous emission light being in a wavelength range other than a range of the wavelength-division-multiplexed signal light, and a judger to judge a continuity state of the operation line by using the signal light output to the operation line and a continuity state of the preliminary line.

Abstract: An optical line terminal which includes an observing unit that observes information of any one or all of an arrival interval of frames, an instantaneous bandwidth under use of a flow, a queue length of a queue temporarily storing the frames, and a traffic type, and a stop determining unit that dynamically determines a sleep time to be a period in which a sleep state where partial functions of the ONU are stopped is maintained, on the basis of the information obtained by the observing unit. The ONU is entered into a sleep state, immediately after communication ends, after a predetermined waiting time passes from when the communication ends, or after a waiting time determined on the basis of the information passes from when the communication ends.

Abstract: The present invention is an adapter for providing wireless communication between a digital multimeter (DMM) and a computer. The adapter has a processor as well as a transmitter operable for transmitting signals to the (DMM) from the processor. The adapter also includes a receiver operable for receiving signals from the DMM, the processor is able to receive the signals from the receiver. The adapter of the present invention also includes at least one radio transmitter operable for providing wireless communication between the processor and the computer. The data measurements obtained through communication with the DMM via the receiver and transmitter are transferred wirelessly to the adapter. The data measurements obtained by the adapter are then transferred wirelessly from the adapter to the computer through the radio transmitter. The radio transmitter is operable to communicate wirelessly with the computer in one or more communication protocols, such as Zigbee and WiFi.

Abstract: A method for performing an optical line analysis of continuous data signals transmitted in a passive optical network (PON). The method comprises determining, from an optical signal of the optical line, at least one of a phase early/late indicator based on a phase position of an input continuous data signal relative to sampling clock signals, a difference phase indicator based on an input phase control code, and a low frequency jitter indicator based on an input phase control code; computing a plurality of statistical measures regarding frequency and amplitude components of a jitter of the input continuous data signal, wherein the statistical measures are computed based on one of the phase early/late information indicator, the difference phase indicator, and the low frequency jitter indicator; and analyzing the plurality of statistical measures to detect optical failures in the PON and determining a root cause of each of the detected failures.

Abstract: In one embodiment, compensating for interference in optical fiber relates to receiving a signal transmitted over the optical fiber, multiplying the signal by a frequency domain equalization (FDE) filter that compensates for the interference to obtain a filtered signal, computing an error in the filtered signal, estimating a gradient based upon the computed error, and updating the FDE filter using the estimated gradient.

Abstract: A correlation system, such as a correlation optical time domain reflectometer (OTDR) system, transmits a correlation sequence, such as an M-sequence, and measures the returns of the correlation sequence over time. The system correlates the transmitted sequence with the returns to provide correlation measurement values that respectively correspond to different distances from the point of transmission. A correlation error compensation element adjusts each correlation measurement value in order to cancel the contribution of the correlation error floor from the measurements to provide compensated measurement values that are substantially free of the effects of the correlation error floor.

Abstract: A method of network communications includes determining an access identifier (AID) for an egress signal through a network interface of a network element, an Optical Transport Network (OTN) multiplexing structure identifier (MSI) associated with the egress signal through the network interface, another AID associated with a defined ingress signal through the network interface, another OTN MSI associated with the defined ingress signal through the network interface, and associating the egress signal and the defined ingress signal based on the AIDs and OTN MSIs. The first OTN MSI is not equal to the second OTN MSI.

Abstract: Systems and methods for Ethernet Passive Optical Network Over Coaxial (EPOC) power saving modes are provided. The EPOC power savings modes allow an EPOC coaxial network unit (CNU) to enter a sleep mode based on user traffic characteristics. The sleep mode may include powering down one or more module of the EPOC CNU, including radio frequency (RF) transmit/receive circuitry and associated circuitry. In embodiments, the EPOC CNU may enter sleep mode based on instructions from an optical line terminal (OLT) or based on its own determination. Embodiments further include systems and methods that allow the EPOC CNU to maintain synchronization with a servicing coaxial media converter (CMC) when it enters a sleep mode.

Abstract: Disclosed is a bidirectional optical transmitting and receiving device which includes a bottom case; a sidewall case; an upper case; a thermoelectric cooler provided on a first portion of the bottom case; a temperature sensor, a light emitting element, and a first lens collecting light emitted from the light emitting element, the temperature sensor, the light emitting element, and the first lens formed over the thermoelectric cooler; a second lens contacting with the exterior via the sidewall case; a filter transmitting light propagated from the first lens to the second lens and reflecting light propagated from the second lens; a third lens coupled with a lower surface of the filter and collecting light reflected from the filter; a light receiving element provided on a second portion of the bottom case and receiving light propagated from the third lens to output an electric signal; a pre-amplifier provided on the second portion and amplifying the electric signal from the light emitting element; and a support

Abstract: In a communication system in which data is transferred by packets, a ranging method in which a receiver, in a given ranging window, periodically compares received data with expected data to find a match. The periodic comparison includes searching for known preamble and/or delimiter sequences of ranging packets and involves timeouts for each search period. In case a match between the known sequences and received sequences is not found and the respective timeout is exceeded, the search and comparison process is restarted and continues until a global timeout is exceeded.

Abstract: An apparatus including: a first port configured to receive a first end of a cable to provide a communication link between (i) the first port, and (ii) a second port coupled to a second end of the cable. The apparatus further includes a processor configured to, during a time that the first end of the cable is coupled to the first port and the second end of the cable is coupled to the second port, (i) receive a command to identify the second port to which the second end of the cable is coupled, and (ii) in response to the command, repeatedly change the state of the communication link at the first port in accordance with a pattern.

Abstract: An improved algorithm for calculating multimode fiber system bandwidth which addresses both modal dispersion and chromatic dispersion effects is provided. The radial dependence of a laser transmitter emission spectrum is taken into account to assist in designing more effective optical transmission systems.

Abstract: Various embodiments of a 16-QAM (quadrature-amplitude-modulation) constellation having one or more subsets of its sixteen constellation points arranged within respective one or more relatively narrow circular bands. Each of the subsets includes constellation points of at least two different amplitudes and may have between about six and about ten constellation points. Each of the circular bands may have a width that is between about 3% and about 20% of the maximum amplitude in the constellation.

Abstract: A system and method for monitoring an optical communication system. The system may include trunk terminals coupled through a trunk path and a branch terminal coupled the trunk path. A monitoring signal routing device within the branch terminal routes a monitoring signal from a branch-drop path to a branch-add path.

Abstract: A method for small scale time increased bandwidth assignment to increase optical network unit ONU downstream energy efficiency includes splitting of downstream scheduling cycles into multiple rounds, using selective ones of the multiple rounds as probing rounds and other than said selective ones of the multiple rounds as fixed rounds, the probing rounds and fixed rounds being cooperatively selected for energy efficiency without limitations in length of the downstream scheduling cycles.

Abstract: One embodiment relates to an integrated circuit which includes a transmitter buffer circuit, a duty cycle distortion (DCD) detector, correction logic, and a duty cycle adjuster. The DCD detector is configured to selectively couple to the serial output of the transmitter buffer circuit. The correction logic is configured to generate control signals based on the output of the DCD detector. The duty cycle adjuster is configured to adjust a duty cycle of the serial input signal based on the control signals. Another embodiment relates to a method of correcting duty cycle distortion in a transmitter. Other embodiments and features are also disclosed.

Abstract: 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.

Abstract: An optical network having a tree-like structure with a main line and a plurality of branches, at least two of the branches comprising a monitoring unit for upstream signalling to the main line, wherein each of the monitoring units comprises a signal generation unit with a light source for generation of a pre-defined optical signal, and the monitoring units are construed to generate pre-defined optical signals which are different from each other, as well as a monitoring unit for generating a periodic upstream signal in such an optical network and a method for monitoring such an optical network.

Abstract: In the configuration of an optical communication system interconnecting a parent station and a plurality of child stations via an optical fiber network equipped with an optical splitter, RE is provided having a measuring unit for measuring a transmission distance or time to a child station, a determining unit for determining a timing when a child station transmits a signal, in accordance with a transmission bandwidth request from the child station, and a signal processing unit for processing a signal received from a child station and transmitting the processed signal to the parent station. When a burst signal is received from each child station at the determined timing, a portion of the header of the burst signal is deleted, and a dummy signal is inserted into the deleted area and a gap area between received burst signals to convert the burst signals into a series of signals to be sent to the parent station.

Abstract: A system includes: a plurality of pixels arranged in a matrix; a reference signal generating unit for generating a ramp signal; A/D converters each arranged correspondingly to each of columns to A/D-convert a signal from the pixel; a counter that performs a count operation according to an output of the ramp signal, and supplies the count signal through the count signal line to the A/D converter; and a counter test circuit that is provided independently from the A/D converter, and tests the counter, based on a matching of the expected value of the count signal with the count signal supplied through the count signal line from the counter. This configuration allows the count signal to be checked concurrently with imaging of an object.

Abstract: A optical time domain reflectometer (OTDR) which sends and receives pulses for multiple frequencies down a fiber under testing (FUT). These frequencies can include frequencies for testing a live FUT and frequencies for testing a dark FUT. The pulses of the various frequencies are sent and received through a single optical connection with the FUT. The number of connections necessary to test the fiber is thus reduced. The OTDR may also include a built in passive optical network (PON) power meter, which measures the power level of the fiber over the same single optical connection.

Abstract: 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.

Abstract: 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.

Abstract: A Gigabit-capable Passive Optical Network (GPON), including an enhanced Optical Line Termination (OLT) and Optical Network Units (ONUs), provides enhanced features, e.g., features defined in XG-PON. One or more of the ONUs are enhanced ONUs. The enhanced OLT communicates with the ONUs via downstream frames and upstream bursts, each downstream frame and upstream burst being compliant with a GPON framing format. The enhanced OLT transmits downstream frames to the ONUs, the downstream frames including downstream sub-frames with at least one downstream sub-frame being an overhead sub-frame that includes information of the enhanced features. The enhanced OLT receives upstream bursts from the ONUs, the upstream bursts including upstream sub-frames, each upstream sub-frame including an upstream identifier field that indicates to the enhanced OLT whether the upstream sub-frame is an overhead sub-frame.

Abstract: 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.

Abstract: Provided herein is a novel approach to simultaneous fiber presence detection and improved laser eye safety of an optical transceiver. The subject optical transceiver is fitted with at least one switch in its receptacle that controls the laser diode and indicates the presence of a fiber (or fibers) within such a receptacle. If a fiber is present within the subject module receptacle, the laser switch is permitted to be “on”, whereas the absence of a fiber will prevent the laser switch from turning on, thereby permitting effective control of the laser at a single point of failure within the entire optical transceiver system. The typical optical transceivers of today exhibit limited optical power output due to eye safety limit criteria.

Abstract: An optical interface device determines whether frequency deviation of a clock signal corresponding to an optical signal from a client side is abnormal based on a stuff amount when subjecting a data signal corresponding to an optical signal input from the client side to a stuffing process, inserts an alarm indication signal (AIS) indicating that the frequency deviation is abnormal into a predetermined region of a data signal when the deviation is determined to be abnormal, and outputs an optical signal generated corresponding to the data signal to a WDM line side so as to transfer the AIS to another component disposed downstream therefrom, so that locating a site where an abnormal state occurs is made easier.

Abstract: An optical control system is described which is capable of maintaining and optimizing a fiber-optic transport system within it's domain of control while interacting with other optical systems which are controlled independently. This allows the optical system to be incorporated as a building block into a larger optical network in a relatively arbitrary fashion. This provides an underlying control system for a non-linear system like optics network that is flexible and extensible.

Abstract: A method comprises: acquiring, for a number nSOP of varied State-Of-Polarization analysis conditions of the input optical signal, nSOP polarization-analyzed optical spectrum traces; mathematically discriminating said signal contribution from said noise contribution within said optical signal bandwidth using said polarization-analyzed optical spectrum traces, said mathematically discriminating comprising: obtaining a differential polarization response that is related to the optical spectrum of said signal contribution by a constant of proportionality; estimating the constant of proportionality of a differential polarization response to the optical spectrum of said signal contribution; estimating the optical spectrum of said noise contribution from said input optical signal, within said optical signal bandwidth using said constant of proportionality and said differential polarization response; and determining said in-band noise parameter on said input optical signal from the mathematically discriminated noise c

Abstract: There is provided a method for determining the in-band noise in agile multichannel Dense Wavelength Division Multiplexing (DWDM) optical systems, where the interchannel noise is not representative of the in-band noise in the optical channel. The method relies on the analysis of two observations of the same input optical signal. In the two observations, the linear relationship between the optical signal contribution and the optical noise contribution (i.e. the observed OSNR) is different, which allows the discrimination of the signal and noise contributions in the input optical signal. In a first approach, the two observations are provided by polarization analysis of the input optical signal. In a second, the input optical signal is obtained using two different integration widths.

Abstract: A system and method of detecting polarity inversion in an optical switching circuit is disclosed. The method includes performing a first round of a port verification process on at least two optical ports, transmitting a payload from at least one optical port in the at least two optical ports, determining if the payload was received at a second optical port in the at least two optical ports, assigning a pair of ports to a first group in the case that the predetermined payload was communicated between the pair of ports, and assigning a pair of ports to a second group in the case that the predetermined payload was not communicated between the pair of ports. The method also includes determining that either the first group of ports or the second group of ports has inverted polarity.

Abstract: A system and method of detecting polarity inversion in an optical switching circuit is disclosed. The method includes performing a first round of a port verification process on at least two optical ports, transmitting a payload from at least one optical port in the at least two optical ports, determining if the payload was received at a second optical port in the at least two optical ports, assigning a pair of ports to a first group in the case that the predetermined payload was communicated between the pair of ports, and assigning a pair of ports to a second group in the case that the predetermined payload was not communicated between the pair of ports. The method also includes determining that either the first group of ports or the second group of ports has inverted polarity.

Abstract: A method in a network device for providing end-to-end connection in a unified optical and coax network, comprising receiving at an integrated node device (IND) a frame from an optical line terminal (OLT), wherein the frame comprises a data frame and a logical link identifier (LLID), and placing the data in a one of a plurality of buffers based on the LLID, wherein the one of the plurality of buffers corresponds to a customer premises equipment (CPE) associated with the LLID, wherein the data frame stays intact in a media access control (MAC) layer.

Abstract: Provided in accordance with the invention is a method for measuring the distance of an object in which a transmitted signal (S) with a pulse train having a prescribed pulse repetition frequency (fw) is generated such that the transmitted signal has a frequency comb in the frequency domain, the transmitted signal is directed onto the object, and a reflected signal (R) reflected from the object is received, the phase difference (?MESS,1) between the transmitted signal and the reflected signal is determined for a prescribed spectral line of the frequency comb, and the distance is determined with the aid of the phase difference.

Abstract: A router comprising an interface module (IM), having an optical path and an electrical path and a speed sensor coupled between an input of the router and an input of the IM. The speed sensor is adapted to receive a packet and detect a speed of the IM connection and in response to the speed of the IM connection being above a threshold value, the speed sensor provides the packet to the optical path of the IM and in response to the relative speed being below the threshold value, the speed sensor provides the packet to the electrical path of the IM.

Abstract: In this application, we have the following examples: (1) Integrating the NID functionality in to the small foot-print of an SFP Module, with one or more of the features below: a) Mounting a NID SoC IC to an existing SFP Printed Circuit Board (PCB); b) Using the power from the SFP module, without requiring separate external power; c) NID SoC having only 2 ports, each with its own MAC and possibly PHY layer; d) NID SoC having an embedded microprocessor, RAM and ROM. Many examples and applications are provided.

Abstract: One aspect provides an optical communication system. The system includes an optical combiner, an optical tap, and a controller. The optical combiner is configured to receive a first optical signal at a first port of a plurality of ports. The optical tap is associated with the first port and is configured to divert a portion of the first optical signal. The controller is configured to monitor the diverted portion and to create an ID message including an identification datum associated with the port in the event that the diverted optical signal is detected.

Abstract: A method, system and computer-usable medium are disclosed for visually indicating the remaining life of a small form factor pluggable (SFP) optical transceiver module. The total number of optical light pulse signals processed by an SFP are compared to a predetermined lifecycle number of signals that can be processed before the SFP enters a failed operating state. The remaining life of the SFP is calculated. A first display visually indicates that the total number of processed signals has not exceeded the lifecycle number of signals. A second display located on the SFP enclosure visually indicates the SFP has reached the end of its lifecycle.

Abstract: In a transmission path monitoring system, a first add section adds a first add signal to a first wavelength division multiplexing signal. A first drop section separates a first drop signal from the first wavelength division multiplexing signal. A first loopback section transfers a monitor signal on a first drop optical transmission path onto a second add optical transmission path. A second add section adds a second add signal to a second wavelength division multiple signal. A second drop section separates a second drop signal from the second wavelength division multiplexing signal. A first communication section transmits the first add signal and the monitor signal and receive the second drop signal and the monitor signal.

Abstract: A system and method is disclosed that allows for the monitoring, analyzing and reporting on performance, availability and quality of optical network paths. The correlation of PM parameter metrics to client connections, coupled with threshold-based alarm generation provides a proactive and predictive management, reporting and analyzing of the health and effectiveness of individual path connections to alert Operational Support (OS) staff and/or customers to signal degradation and impending Network Element (NE) failures. The system and method performs in real-time processing intervals required for alarm surveillance in a telecommunications network.

Abstract: A system and method for performing lethality assessment utilizes frequency domain reflectometry (FDR) to determine impact point and damage propagation faults in a detection surface. The detection surface has a conductive layer capable of propagating radio frequency (RF) signals. At least one signal transmit/receive port on the detection surface injects a radio frequency (RF) interrogation signal into the detection surface and at least two signal receive-only ports on the detection surface spaced a distance apart from each other and from the signal transmit/receive port receive reflected radio frequency (RF) signals of the interrogation signal. A frequency domain reflectometry measurement system coupled with the transmit/receive port and signal receive-only ports measures frequency responses of the ports compared to predetermined baseline measurements and determines the precise location of an impact point and damage propagation fault in the detection surface by triangulation.

Abstract: To detect the performance degradation of an optical communication transmission system after it becoming operational, thereby preventing the reliability of the system from lowering. In an optical communication transmission system, one of optical transmitter-receivers in a redundant-structured system is an active optical transmitter-receiver, and the other optical transmitter-receiver is a standby optical transmitter-receiver. The optical transmitter-receiver includes a loopback device through which the signal light of a transmitting section of the optical transmitter-receivers is inputted to a receiving section, and an operating-system switching scheduling device for regularly switching the operating system is provided.

Abstract: Embodiments of the present disclosure describe a method and an apparatus for testing an optical network, which may be applicable to an integrated OTDR and the field of optical network technologies. The method includes obtaining a maximum test time of a single group test; dividing a total test time into at least two groups of single group test time that is not greater than the maximum test time when the total test time is greater than the maximum test time of the single group test; performing the single group tests in sequence according to each single group test time; and instructing optical network equipment to restore to a normal working state when the single group test time corresponding to each single group test ends.