Abstract: Systems and methods for identifying a fault location in an optical network are disclosed. In accordance with one embodiment of the present disclosure, a method for identifying a fault location in an optical network comprises monitoring, by a network element, an eastward optical path and a westward optical path for faults. The method further comprises transmitting, by the network element, a first data packet along the eastward path and a second data packet along the westward path. The first and second data packets comprise an eastward fault indicator and a westward fault indicator comprising information associated with any eastward or westward faults occurring on the eastward or westward paths. The fault indicators indicate the existence of an eastward or westward fault and the network element that detected the fault.

Abstract: The present disclosure relates to a passive optical network (PON) and provides a method for maintaining the PON, the optical network unit (ONU), and the optical line terminal (OLT) to solve the problem of the ONU being in a constant light emitting state. The method of the present disclosure allows the OLT to determine whether the continuous seizure time of an upstream channel exceeds the preset threshold, and if so, detect the failed ONU that continuously seizes the upstream channel and use a control message or control signal to instruct the failed ONU to turn off power supply to its transmitting circuit.

Abstract: A computerized system and method for managing a passive optical network (PON) is disclosed. The system includes a detection and analysis module adapted for receiving uploaded measurement data from an optical line terminal (OLT) and at least one optical network terminal (ONT), and at least one of technical tools data, service failure data, and outside plant data. The detection and analysis module is adapted for determining a source of failure or potential failure in the PON by correlating the uploaded measurement data and the at least one of technical tools data and service failure data with information stored in a memory medium for the OLT and each ONT.

Abstract: The invention relates to a network comprising at least one host device having an interface card connected to a backplane of said host device, wherein said interface card comprises at least one cage for receiving a pluggable module which performs a traffic management of data transported via at least one optical fiber connected to said pluggable module.

Abstract: Provided are a shared mesh protection switching apparatus and method. The shared mesh protection switching apparatus includes a plurality of linear protection switching processors allocated to the linear protection domains respectively and configured to provide a switching report signal in response to fault occurrence in the corresponding linear protection domains or a linear protection switching operation, and perform a function of limiting use of the shared section in response to a provided lock signal, and a mesh protection switching processor configured to select at least one linear protection domain to be limited in use of the network resources of the shared section according to a predetermined reference when the switching report signal is provided and provide the lock signal to a linear protection switching processor corresponding to the at least one selected linear protection domain.

Abstract: A method of monitoring (200) an optical fiber comprises modulating (210) an optical signal with a traffic signal; modulating (220) the optical signal with an incoherent optical frequency domain reflectometry, IOFDR, test signal; transmitting (230) the doubly modulated optical signal onto an optical fiber at a first end of the fiber; detecting (240) scattered radiation output from the first end of the fiber; and analyzing (250) the detected scattered radiation using incoherent optical frequency domain reflectometry to determine a distance to a break in the optical fiber. Apparatus suitable for carrying out the method is also described, as well as an optical communications network employing the method.

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: An apparatus comprising an optical transmitter, a coarse tuner coupled to the optical transmitter and having a first tuning range, a fine tuner coupled to the optical transmitter and having a second tuning range smaller than and within the first tuning range, a wavelength division demultiplexer coupled to the optical transmitter and to a plurality of optical fibers, and a detector coupled to the optical transmitter and the wavelength division demultiplexer. A network component comprising at least one processor configured to implement a method comprising detecting an Optical Time Domain Reflectometry (OTDR) signal spectrum that has a modulated pattern, and detecting a reflected OTDR signal spectrum that has a shifted modulated pattern comprising a frequency shift with respect to the OTDR signal spectrum and a time shift proportional to the frequency shift.

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: 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 splitter for a passive optical network for telecommunication signal transmission with an optical line terminal includes a wavelength selective optical electrical converter, an AC/DC splitter, an energy reservoir and optical switches, where the splitter comprises also a data transmission processing module by which the optical switches can be controlled according to data signals transmitted from the optical line terminal.

Abstract: Delivering multicast data traffic over a communication network includes a first network node delivering multicast data traffic to second network nodes. The first and second network nodes are connected by a transmission network in a ring architecture and implement a point-to-multipoint layer 2 protocol. A method includes at the first network node: collecting alarms signals indicative of a failure along the whole ring and of the second network nodes. Based on a current state of the alarm signals, delivering the multicast data traffic either in a first delivery direction along the ring, or in a second delivery direction along the ring opposite to the first delivery direction, or in both the first and second delivery directions. At each of the second network nodes: collecting alarm signals indicative of a failure of the transmission network locally to the second network node and of the second network node.

Abstract: The present invention relates to a method, device and system for fast protection of an optical network system, in particular for a Passive Optical Network (PON), such as a Gigabit-capable Passive Optical Network (GPON). In the method, communication failure between a first optical network device and a first optical line termination device is detected. Switching of functionality from the first optical line termination device to a second optical line termination device is initiated, and a control message is sent from the second optical line termination device to the first optical network device such that the first optical network device is prevented from moving into initial state. Furthermore, the method comprises determining and setting timing settings for the first optical network device.

Abstract: The present invention relates to a method and devices for fast protection of an optical network system, in particular for a Passive Optical Network (PON), such as a Gigabit-capable Passive Optical Network (GPON). In the method, it is detected that the communication from a first optical network device is lost. Switching of functionality is initiated from a first optical line termination device to a second optical line termination device, and a control message is sent from the second optical line termination device to the first optical network device such that the first optical network device is prevented from moving into initial state. Furthermore, the method comprises determining and setting timing settings for the first optical network device.

Abstract: A method for diagnosing an optical communication network having a control system, an optical hub, and multiple optical network terminators. The hub communicates with all the network terminators via an inband management channel. In case one network terminator disturbs the communication from the network terminators to the hub and the communication from the hub to the network terminators is functional, the control system sends a shut-off command to one network terminator, checks if the disturbance is gone, if the disturbance is not gone, sends a pulse mode activation command to this network terminator, checks if there is a superposition signal of the disturbance signal with a pulse mode signal and marks the network terminator as bad, if the pulse signal is not superimposed.

Abstract: A method and apparatus for detecting Passive Optical Network (PON) failures, and a PON system are provided to obtain the monitoring information of a peer device before a PON system failure occurs. The method includes: obtaining monitoring information of an Optical Line Terminal (OLT) and an Optical Network Unit (ONU); and determining a failure of a passive ONU according to the obtained monitoring information of the OLT and the ONU. The monitoring information of the peer device is obtained before a PON system failure occurs. Thus the failure is discovered in time, quick troubleshooting is ensured, and the costs of system maintenance are reduced.

Abstract: An integrated cable configured to communicate over much of its length using one or more optical fibers includes an electrical connector at least one end. The electrical connector at a first end of the integrated cable and an optoelectronic device coupled to or included in the other end of the integrated cable may utilize a bidirectional status link to transmit status data to each other. If the status data indicates that optical signals transmitted over the optical channels between the two devices are not potentially exposed to view, the two devices may operate above nominal eye safety limits. Otherwise, the two devices may operate at or below nominal eye safety limits. If the second optoelectronic device is not status-link enabled, the first optoelectronic device may operate at or below nominal eye safety limits.

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 multi-wavelength optical transmission system includes a plurality of primary optical transmitters, each being configured to provide directly modulated analog optical signals at non-uniformly spaced apart wavelengths. An optical multiplexer having a plurality of optical input ports receives the analog optical signals from each of the plurality of primary optical transmitters and provides a wavelength division multiplexed signal over an optical fiber coupled at an output thereof. A spare optical transmitter is coupled to an input port of the optical multiplexer and, in response to detecting failure of a failed one of the plurality of primary optical transmitters, is tuned to provide a directly modulated analog optical signal at a spare wavelength that is selected as to be non-uniformly spaced relative to at least some of the non-uniformly spaced apart wavelengths according to tuning data.

Abstract: A plurality of transmission devices are communicably coupled to each other in a first transmission network. A first transmission device receives data from a second transmission device, and extracts, from the received data, attribute information including report-destination identification information identifying a third transmission device and routing information identifying a transmission route through which the data has been transmitted to the first transmission device via the second transmission device in the first transmission network.

Abstract: A pulse transmission technique is used for wireless communication between a microcomputer (13) having a debugging support circuit (17) and a debugger (13). The pulse transmission technique is based on magnetic field coupling between a first coil (14) provided for the microcomputer and a second coil (8) coupled with the debugger. During an initialization operation, the microcomputer performs a process of configuring a communication condition of the wireless communication to perform the wireless communication. The microcomputer awaits control from the debugger when the microcomputer establishes communication with the debugger. The debugger awaits establishment of the communication and proceeds to control of the microcomputer in accordance with the wireless communication. It is possible to provide contactless interface for system debugging without the need for a large antenna or a large-scale circuit for modulation and demodulation.

Abstract: In an embodiment, an apparatus comprises a switch configured to control bi-directional communication in a first channel of a fiber optic network between the switch and a number of devices and in a second channel of the fiber optic network between the switch and a number of health assemblies in the number of devices. The fiber optic network comprises a number of lines, each line connecting one of the number of devices to the switch. Each health assembly is configured to send and receive a number of optical signals in the second channel.

Abstract: There is provided an optical network apparatus included in an optical network in which alarm information including a type and a position of a generated failure is transferred, the optical network apparatus including: a reception unit configured to detect alarm information from a received signal, generate alarm code information representing content of an alarm from the alarm information, and transmit a signal including the alarm code information; a transfer unit configured to switch and transfer the signal transmitted from the reception unit; and a transmission unit configured to replace the alarm information included in the signal transferred from the transfer unit, based on the alarm code information, setting information of the transmission unit and setting information of the reception unit, and to transmit the signal including the replaced alarm information.

Abstract: An optical-fiber-network (OFN) radio-frequency identification (RFID) method for deploying and/or provisioning service and/or locating faults in an OFN. The method includes providing at least one RFID tag on at least one OFN component of a plurality of OFN components that constitute an OFN and writing OFN component data to the at least one RFID tag that relates to at least one property of the OFN component associated with the RFID tag. The RFID tag data is written to and read from the RFID tags using one or more mobile RFID readers. The OFN component data is recorded and stored in an OFN database unit. The plurality of OFN components are deployed and operations of the OFN are provisioned using the OFN component data. The method may also include using the OFN component data and a plurality of locations on a spatial map to locate a fault in the OFN.

Abstract: An optical test termination device (100) for use in optical network comprising a passive optical element (102) and a first optical coupler (104) and a second optical coupler (106) for coupling the optical test termination device (100) to an optical fiber (108, 110, 202). The passive optical element (102) comprises an input for receiving a test signal from the network and an output for outputting a response signal towards the network, wherein in response to the test signal the passive optical element (102) is operable to output the response signal, wherein said response signal differs from said test signal.

Abstract: The present invention provides an optical signal-selection switch module which is used in a method for simultaneous real-time status monitoring and troubleshooting of a high-capacity single-fiber hybrid passive optical network that is based on wavelength-division-multiplexing techniques.

Abstract: The present invention provides a bidirectional optical signal traffic-directing and amplification module which is used in a method for simultaneous real-time status monitoring and troubleshooting of a high-capacity single-fiber hybrid passive optical network that is based on wavelength-division-multiplexing techniques.

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 method for locating fiber events and an optical network and network device are provided. The method for locating fiber events includes: determining the distance between an event and an OLT, measuring the optical loss of the optical channel between the OLT and an ONU or ONT at the peer end of the measured fiber link, and, according to the measured optical loss of the optical channel, judging whether the event occurs on the measured fiber link, and if so, determining the location of the event on the measured fiber link according to the distance between the event and the OLT.

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 method for channel protection switching of an optical network device, an Optical Transport Network (OTN) device, and a Passive Optical Network (PON) device is provided. The method includes detecting, by the PON device, whether an OTN alarm indication signal is received after discovering a fault. If the OTN alarm indication signal is received, the alarm generated by the PON device is suppressed so that the PON device does not perform channel protection switching. The PON device detects whether an OTN alarm indication signal is received, and suppresses the alarm generated by the PON device so that the PON does not generate futile alarms or lead to futile switching when the OTN fails but the PON works normally.

Abstract: Reduction in power consumption at low costs is realized by a system with apparatuses connected with each other. A switch device comprises transmission/reception unit each connected to each of apparatuses through a communication cable for transmitting/receiving a signal to/from each apparatus, and a connection switching unit for switching connection between the apparatuses by switching connection between the transmission/reception unit. Further provided are a reception state monitoring unit for monitoring a signal reception state of the transmission/reception unit, and a transmission stopping unit for executing signal transmission stopping processing according to a monitoring result obtained by the reception state monitoring unit with respect to other transmission/reception unit to which connected through that communication cable is other apparatus having a connection relationship with the apparatus to which the transmission/reception unit is connected through the communication cable.

Abstract: The invention relates to a protection device for removing signal interference in a passive optical network and to a corresponding passive optical network and to a method for removing signal interference in a passive optical network.

Abstract: The present invention discloses a method and system for tracking signaling in an automatically switched optical network (ASON), wherein the method comprises a step of setting a signaling tracking filtering condition for a corresponding signaling tracking task, and the following steps that: an ASON node collects and reports a received or sent signaling message when there exists a task tracking request; and when the reported signaling message is determined meeting the signaling tracking filtering condition of the current signaling tracking task, the reported signaling message is resolved to obtain the signaling message of the signaling tracking task. The invention realizes a signaling tracking scheme in an ASON and can establish multiple signaling tracking tasks at the same time, as each signaling tracking task can set its own signaling tracking filtering condition; a flexible signaling tracking is achieved.

Abstract: The present disclosure provides improvements with respect to in-band control plane signaling, virtualized channels, and tandem connection monitoring in optical networks utilizing Synchronous Optical Network (SONET), Synchronous Digital Hierarchy (SDH), Optical Transport Network (OTN), and the like. In an exemplary embodiment, the present disclosure includes an optical network operating a control plane with in-band signaling utilizing SONET/SDH path level overhead. In another exemplary embodiment, the present disclosure includes an optical network operating virtualized SONET/SDH or OTN channels with manually cross-connections at intermediate line terminating elements. In yet another exemplary embodiment, the present disclosure includes a tandem connection monitoring selection method across multiple operator domains.

Abstract: A system and method for fault identification in optical communication networks. One or more repeaters in the system includes a loop back path that couples an output a first amplifier for amplifying signals carried in a first direction through a repeater to an input of a second amplifier for amplifying signals carried in a second direction through said repeater. Fault analysis is conducted using loop gain data associated with test signals transmitted on the first or second paths and returned on the opposite path through the loop back paths.

Abstract: An apparatus and method for fault indication and localization in a Passive Optical Network (PON) comprising a multistage power splitter (100, 200, 300) with at least one 1:N splitter (120, 221, 222, 321, 322) followed by N items of 2:M splitters (131, 132, 231-233, 331-336), wherein N and M are integers greater than 1. The apparatus also comprises an Optical Time Domain Reflectometry (OTDR) device (110, 210, 310) capable of inserting an OTDR signal into the power splitter (100, 200, 300), and adapted to insert the OTDR signal between the first stage of the at least one 1:N splitter (120, 221, 222, 321, 322) and the second N items of 2:M splitters (131, 132, 231-233, 331-336).

Abstract: A method and apparatus for buffering an encoded signal having a plurality of codewords for a turbo decoder is provided. The method comprises de-interleaving each sub-block of the codeword received at the turbo-decoder; and storing LLRs of the de-interleaved codeword LLRs into an input buffer. Thereafter, each of punctured locations, if any, in the de-interleaved codeword is indicated to a read logic for enabling the latter to fill in each of those locations with a pre-determined LLR value as and when a read request corresponding to one of those locations arrives. This method obviates the need for storing the pre-determined LLRs at the punctured locations into the input buffer and thereby cuts down the input latency of turbo decoder significantly for higher code rates.

Abstract: Provided are an optical output power control method that provides optical communication without harming the human body even when a transmission line is cut or no optical network unit (ONU) accesses a communication system, and a passive optical network (PON) system using the method. In the method, an optical signal having a predetermined period is transmitted when an optical communication system is in an abnormal state, wherein the predetermined period includes a laser-on time interval in which the optical signal has a normal power level and a laser-off time interval in which the optical signal is off or has a power level lower than the normal power level, so that the optical communication system performs optical communication without harming the human body even during the abnormal state.

Abstract: A method and corresponding apparatus for diagnosing problems on a time division multiple access (TDMA) optical distribution network (ODN) is provided. An example method may include: (i) measuring no-input signal power level on a communications path configured to carry upstream communications between multiple optical network terminals (ONTs) and an optical line terminal (OLT) in a passive optical network (PON) at a time no upstream communications are on the communications path from the ONTs to the OLT; (ii) comparing the measured no-input signal power level to a threshold; and (iii) generating a notification in an event the threshold is exceeded. Through the use of this method, faults in optical transmitters, such as bad solder joints, can be determined. Such faults may cause errors in parameters, such as ranging or normalization parameters, associated with communications. By determining the faults, the time required to resolve communications errors can be reduced.

Abstract: Systems are provided for gathering location data pertaining to a fiber optic network. One system includes a sensor, a geolocation system, a processor in communication with the sensor and the geolocation system, and a user control panel. The sensor is configured to receive an operational input indicating the condition of a network, and the geolocation system is configured to determine the location, such as a latitude and longitude, of the optical fiber. The processor is configured to associate outputs from the sensor and the geolocation system. The processor may be configured to store the outputs on a storage media. A transmitter may also be provided to transmit the data to a remote location for analysis and display. An associated method for gathering location data is also provided.

Abstract: A method for allocating faults in a passive optical network (PON) by placing a number of passive unique optical correlators in a number of respective diagnostic points of the PON, each of the passive unique optical correlators being responsive to an optical diagnostic signal by returning a predetermined unique matching signal; by further transmitting the diagnostic optical signal in the PON towards the diagnostic points to receive upstream response signals from the correlators. Upon detecting presence or absence, in the received response signals, of a predetermined unique matching signal expected from a specific optical correlator, judging about a fault in proximity of the respective specific diagnostic point.

Abstract: In an optical network a 1+1 bidirectional protection system is presented. Each node across a link has photodiodes to monitor the power of signals received by the node on receiving working and protection optical fibers and also optical switches connected to transmission working and protection optical fibers to modulate signals to its counterpart node across the link. When a node detects a fault in the receiving working optical fiber, not only does the node switch to the receiving protection optical fiber, but it also switches to the transmission protection optical fiber to signal the fault to the node across the link. The optical switches on transmission working and protection optical fibers allow the two nodes across the link to signal each other at a protocol-less or primary protocol level for the link to revert back to its initial state.

Abstract: Systems and methods for identifying a fault location in an optical network are disclosed. In accordance with one embodiment of the present disclosure, a method for identifying a fault location in an optical network comprises monitoring, by a network element, an eastward optical path and a westward optical path for faults. The method further comprises transmitting, by the network element, a first data packet along the eastward path and a second data packet along the westward path. The first and second data packets comprise an eastward fault indicator and a westward fault indicator comprising information associated with any eastward or westward faults occurring on the eastward or westward paths. The fault indicators indicate the existence of an eastward or westward fault and the network element that detected the fault.

Abstract: Provided are a fault localization apparatus based on an optical communication network and a method thereof. In the fault localization apparatus according to the present invention, a downstream light source is used as a monitoring optical signal instead of using an additional monitoring light source and a subcarrier multiplexing (SCM) monitoring pulse signal of a certain frequency band having no interference with a frequency band of a downstream data signal is used and thus a fault position may be detected at low cost.

Abstract: The present invention discloses a fault localization method and a fault localization apparatus in a Passive Optical Network (PON) and a passive optical network having the same. A fault localization method in PON according to the present invention comprises a) configuring an optical path of a remote node (RN) selectively by electric power being fed temporarily only when necessary, while the PON is regularly being operated as a passive network; and b) detecting a fault occurring on the selectively configured optical path by inserting a monitoring signal of an OTDR unit, which is positioned in a central office (CO), through the selectively configured optical path.

Abstract: A method and apparatus is disclosed for use in fiber optic signature recognition to analyze buried optical fiber to identify a non-threat area along a fiber route and to discontinue monitoring for disturbances along that area of the cable route. The technique includes determining the location of the zone of non-threatening disturbances from comparing an optical signal to the representation of a prearranged optical signal identified as friendly. Once a zone of non-threatening disturbances is identified, all subsequent disturbances in that zone are considered friendly. Cable monitoring is discontinued in the identified zone of non-threatening disturbances so as to avoid monitoring fiber cable when permitted workers are in the area.

Abstract: Various high loss loop back (HLLB) repeater architectures are disclosed that enable selectively monitoring (e.g., measuring, analyzing, etc) of Rayleigh signals from both inbound and outbound directions of an optical communication system. In one such embodiment, first and second optical test signal frequencies (or ranges) are used, in conjunction with selective filtering, for monitoring the outbound and inbound paths, respectively. The repeater architectures allow optical time domain reflectometry (OTDR) monitoring techniques to be employed, for example, in particularly long repeater spans, such as those in excess of 90 km in length.

Abstract: A system and method is disclosed that allows real-time processing of child OPOI and rider service alarms from a parent OPOI which determines if one or more STS alarms are associated with a rider service, a child OPOI, or a parent OPOI. The system and method performs in real-time processing intervals required for alarm surveillance in a telecommunications network.

Abstract: A method, apparatus, and program, for evaluating an optical network node. The method comprises providing at least one communication path of the node with a capability by which lasing can occur in the communication path, and detecting whether lasing has been established in the communication path to determine whether the optical node is operational. If no lasing is detected in the detecting, a fault exists in the communication path. The method further comprises determining an insertion loss in the communication path, and determining whether the insertion loss is comparable to a predetermined insertion loss, to confirm whether the node is configured correctly.