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: 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: 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 and device for indicating an uncorrectable data block. The method includes: if a forward error correction decoding fails, setting synchronization character of at least one of the corresponding data blocks to a first character; and performing line decoding on the data block with the set first character, and outputting decoded data. With the invention, indicating the uncorrectable data block Simple and effective to a line decoding module can be implemented in case of a failure of FEC decoding.

Abstract: An optical correlation apparatus is described which forms first and second parallel optical signals in response to a serial input data stream. The first parallel optical signal is arranged to have bright pulses represent binary 1 and the second parallel optical signal is arranged to have bright pulses represent binary 0. A channel select means, such as an optical switch or amplitude modulator, deselects or blocks channels in the first parallel optical signal which correspond to binary 1 in a reference data string and also deselects or blocks channels in the second parallel optical signal which correspond to binary 0 in the reference data string. The remaining optical signals are combined at one or more detectors. Where the input data matches the reference data string each bright pulse in the first and second parallel optical signals is deselected and the detector registers zero intensity. However when there is any mismatch at least one channel will pass a bright pulse to the detector.

Abstract: A method, system and apparatus for managing alarms in a Long Reach Passive Optical Network (LR-PON) system are disclosed. The method includes: obtaining a PON signal from an Optical Line Terminal (OLT) or an Optical Network Unit (ONU) on one side; checking whether the obtained PON signal fails; and notifying the ONU or the OLT on the other side if the PON signal fails. The method, system and apparatus under the present invention monitor the LR-PON transmission quality and process various alarm indications raised in the LR-PON signal monitoring.

Abstract: Passive optical networks can experience faults that are unrecoverable. An embodiments of the present invention is a hybrid passive optical network configured to protect a primary optical path employing a switch to transmit data from the primary path to a secondary path in a passive manner. In an event data flows through both the primary path and the secondary path, the optical switch may be configured to monitor the primary path. In such an embodiment, the optical switch is a protection optical switch that is sensitive to monitoring an optical signal that flows on the primary path. If the switch detects a loss of signal on the primary path, the optical switch automatically switches delivery of the optical signal from the primary path to the secondary path, via the optical switch to allow an optical line terminal to receive optical signals virtually uninterrupted.

Abstract: Detection and characterization of laser clipping within communication devices. Identification of one or more harmonics associated with a fundamental frequency by which signaling is effectuated within the communication system for laser clipping identification. Appropriate spectral signal analysis is made to identify the presence of characteristic(s) (e.g., energy, amplitude, phase, and/or other characteristic(s)), if any, at one or more harmonic frequencies within a received signal. Appropriate time correlation is performed to distinguish whether or not characteristic(s) associated with at one or more of these harmonic bands is a result of laser clipping or from some other source (e.g., such as other signals within a communication system that happened to reside at those respective harmonic bands). Such appropriate identified correlation between characteristic(s) corresponding to a fundamental frequency band of the communication signal and characteristic(s) corresponding to one or more harmonics (e.g.

Abstract: There is provided an optical transmission system including: an optical transmitting apparatus including: a first processing circuit configured to process a transmission signal to be transmitted, a second processing circuit configured to process overhead data, the processed overhead data being multiplexed to the transmission signal, a retaining circuit configured to retain the overhead data, the retained overhead data being multiplexed to the transmission signal; and an insertion circuit configured to generate an identifier to be inserted into the retained overhead data; and an optical receiving apparatus including a detecting circuit configured to receive the transmission signal transmitted from the optical transmitting apparatus, and detect the identifier, wherein, when the overhead data is a predetermined state, the first processing circuit multiplexes the retained overhead data into which the identifier is inserted and the detecting circuit detects the identifier.

Abstract: Systems and methods for triggering fault information insertion in an optical network are disclosed. In accordance with certain embodiments of the present disclosure, a method may include detecting, by a network element, occurrence of an event. The network element may also determine whether the event comprises a triggering fault condition in which fault information is to be communicated. The network element may additionally insert fault information into a data packet. The network element may further communicate the data packet to at least one neighboring network element.

Abstract: A communication network access device is adapted for duplex communication and provides transmit and receive signal paths. A controllable socket is coupled to the transmit and receive signal paths and linked to a control interface for activating/deactivating the control interface. A pluggable module is coupled to the transmit and receive signal paths via the controllable socket in an activated status and to a transmission path carrying uni-directional signals. The module includes a first optical device and a splitter in the transmission path and is coupled to a second optical device via the splitter. The second optical device responds to a portion of uni-directional signals provided by the splitter for placing the communication access device in a link up condition for uni-directional signals provided by the first optical device to the transmission path serving an optical local area network.

Abstract: In a passive optical network system, a parent station includes a reception circuit that receives an optical signal from each of child stations using a threshold used to identify if the optical signal is 0 or 1; a bandwidth setting unit that determines a time at which each child station sends an optical signal; a storage unit that stores thresholds and intensities of optical signals received from the child stations; and a control unit that sets a threshold, stored corresponding to a sending time, in the reception circuit to control a reception of an optical signal. The control unit has a function that compares an intensity of a signal received from each child station at an optical signal reception time with information stored in the storage unit to detect and determine a fault in the child station or in the optical fiber connected to the child station.

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: A node comprising: an ingress port configured to receive data; a plurality of egress ports configured to transmit data; a routing table configured to provide, at least part of, both a preferred routing path and a recovery routing path; a data tag engine configured to read a tag, associated with the data, that indicates the routing state of the data and, based at least in part upon the tag determine whether to use the preferred routing path or the recovery routing path for a selected path, and determine if the tag is to be modified to indicate a change in the routing status of the data; and a routing engine configured to utilize the selected path to determine the egress port from which to transmit the data.

Abstract: A method and apparatus for regulating rogue behavior in optical transmission devices. The apparatus, for example, may be implemented in one or more of the ONTs in a PON. The ONT includes an optical transmitter that may be disabled by a command generated by the ONT itself if rogue behavior is detected or suspected. To detect rogue behavior, at least one output indictor, such as LBC or MPC, is monitored during one or more monitoring windows. If monitoring indicates that the optical transmitter is transmitting more than a pre-determined threshold, a suspect rogue flag is set, for example in an I2C register. The register is read, preferably a number of successive times, and a determination is made whether to disable the optical transmitter. In some embodiments, the OLT is queried as part of this determination. The disability may be permanent, until a manual service operation, for example, or temporary.

Abstract: There is provided an abnormal light cut-off system in which even when a high power light is inputted from an optical fiber connected to a user side apparatus by a malicious user or an accident, a trouble rate is low, the abnormal light is cut off at high sensitivity, and security is high.

Abstract: This disclosure relates to detection of optical fiber failure and implementation of protection switching in a passive optical network (PON). A protection switch determines whether there is an optical fiber failure in a fiber link between an OLT and a group of ONTs. In the case of an optical fiber failure, an optical fiber may be physically cut or damaged, causing the optical fiber link to be disabled. A protection switch may detect an optical fiber failure by determining a peak optical power of at least a portion of an upstream optical signal transmitted from one or more ONTs via the optical fiber link. If the peak optical power is less than a threshold value, the protection switch may detect a fiber failure. In response to a detected fiber failure, the protection switch may switch upstream and downstream PON transmissions from a primary optical fiber to a secondary optical fiber.

Abstract: The subject matter described herein includes providing virtual 1:N automatic protection switching and dynamic, in service configuration change for optical network interface equipment. According to one aspect of the subject matter described herein, a method for providing virtual 1:N automatic protection switching (APS) for optical network interface equipment is disclosed. The method includes configuring N optical network interface cards (ONICs) as working cards, each working card having sending and receiving optical interfaces, wherein N is an integer greater than 1. A single ONIC is configured as a protection card for providing N optical interfaces for providing redundant interface protection for each of the optical interfaces on the N working cards.

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: An interface between a network component and an optical fiber section communicates with a remote interface and a remote network component at an opposite end of the optical fiber section through over-modulation of optical signals sent between the interfaces and network components. The over-modulation is at frequencies much lower than the ordinary modulation of the optical signals. The over-modulation allows communication between the interfaces for performing management, testing and maintenance operations and permits superior detection of faults in the optical fiber section.

Abstract: The present invention encompasses a method for 1+1 protection of an optical transmission path comprising a working path and a protection path that connect a first and second terminal node. In a working mode, an optical transmission signal is transmitted via the working path from the first to the second terminal node. At the second terminal node, the optical transmission signal is split into two optical sub-signals, and one of the optical sub-signals is sent via the protection path to a protection-path connection node as a working-path control signal. In the case of an interruption of the signal transmission via the working path, the protection-path connection node detects the absence of the working-path control signal and switches the system from the working mode to a protection mode in which signal transmission is conducted via a separate protection path.

Abstract: A communication light detecting device interconnecting light transmission paths and collocated therebetween, comprises: an optical coupling body including a core portion for photo coupling with the light transmission paths, and a light extracting portion for extracting a part of the communication light as a leakage light; and a light detecting portion having a light receiving member for receiving the leakage light. The light extracting portion is preferable to possess a lower refractive index than that of the core portion. Besides, the light extracting portion is preferable to include a light detecting use groove with a groove width of 50 ?m or more and 140 ?m or less formed by cutting and separating the core portion. Besides, the light extracting portion is preferable to be the optical coupling body in which outer diameter of the core portion is different from the outer diameter of a core of the light transmission path.

Abstract: The present invention provides for an optical cable and methods for interconnecting modular components with optical fibers. Each optical fiber is electronically labeled with a unique serial number such that interconnections using the optical fibers can be accurately audited.

Abstract: The present invention discloses a method for indicating client signal fail in an optical transport network, including: adding CSF indication bits to an Optical Channel Payload Unit k (OPUk) or/and OPUk-Xv multiframe to indicate whether a client signal is failed; detecting the CSF indication bits of a PSI in the received OPUk or/and OPUk-Xv multiframe, and when the number of continuously detected CSF indications exceeds a preset threshold, indicating to perform a link protection switch. The present invention also discloses an apparatus for implementing the above method. The present invention can avoid the case of APS fail due to the too long CSF time delay; the indication method is simple and the implementation is convenient; and a plurality of CSF indications are used in the multiframe, thus the indication is more flexible.

Abstract: An information processing method is disclosed according to the embodiments of the present invention. The method includes: A node receives a first message from overhead of a first dimension; the node searches for local configuration information, where the local configuration information includes the overhead of the first dimension of a protection path, a protection resource of the first dimension of the protection path, overhead of a second dimension of the protection path, and a protection resource of the second dimension of the protection path; according to the local configuration information and the first message, the node determines a protection path correlated with the first message and determines overhead of the second dimension correlated with the first message; and the node sends a second message to a node adjacent to the second dimension through the overhead of the second dimension correlated with the first message, according to the first message.

Abstract: A wavelength division multiplexing (WDM)-time division multiplexing (TDM) passive optical network (PON) remote terminal (RT) is provided. The wavelength division multiplexing (WDM)-time division multiplexing (TDM) passive optical network (PON) remote terminal (RT), includes: a WDM-TDM converter configured to convert a WDM downstream optical signal that is received from a central office terminal (COT) into a TDM downstream optical signal or to convert a TDM upstream optical signal that is received from an optical network terminal (ONT) into a WDM upstream optical signal; an error detector configured to detect an error; and a controller configured to, in response to an error being detected, transmit the WDM upstream optical signal to the COT via a first standby link or transmit the TDM downstream optical signal to the ONT via a second standby link.

Abstract: A standard test device is used to test the interoperability of a Synchronized Optical Network (SONET) optical interface, e.g., a 1+1 protected SONET interface. In one embodiment, two test sets, under the common control of a master controller, can be connected respectively to the working and protect lines of an optical interface. The controller then operates the test sets to test the operation of the interface under the Automatic Protection Switching (APS) protocol to verify interoperability based on the standards incorporated in the test sets while requiring minimal operator intervention. Alternatively, a single test set can include two connections that are connected, respectively, to the working and protection lines of the interface being tested. The test set can then test the operation of the interface under the APS protocol to verify interoperability based on the standards incorporated in the test set.

Abstract: 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.

Abstract: A system and methods include generating an optical time domain reflectrometry signal; transmitting the optical time domain reflectrometry signal on a first fiber path in a first direction through at least one optical amplifier; receiving a reflection of the optical time domain reflectrometry signal on the first fiber path in a second direction opposite the first direction; transmitting the reflected optical time domain reflectrometry signal on a second fiber path in the second direction, where the second fiber path is not the first fiber path; and determining a location of a fault on the first fiber path based on the reflected optical time domain reflectrometry signal.

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: A system and method for responding to a failure in a communications network. The failure is detected by a router, which then transmits data from the protection port. A signal is sent from the router to a optical cross-connect system indicating the failure and causing the optical cross-connect system to connect the protection port of the router to a working port of the OXC.

Abstract: An optical transmission device for controlling an optical signal output includes a return light detection section for detecting return light of the optical signal transmitted via the optical transmission line; a superimposed light transmission section for generating superimposed light having a superimposed basic low-frequency wave and transmitting the light when return light is detected by the return light detection section; a return light identification section for identifying the return light detected by the return light detection section as Fresnel light caused by a disconnection of the optical connector or Stokes light caused by stimulated Brillouin scattering based on an analysis result of the return superimposed light with respect to the superimposed light transmitted by the superimposed light transmission section.

Abstract: The embodiments of the invention provide a method of routing convergence in a control plane of an intelligent optical network, which includes: a function unit perceiving a service link state transmitting an alarm notification message indicating a failure in a service link to a routing protocol unit when the service link is in failure; the routing protocol unit confirming a service link failure in the control plane according to the alarm notification message. The embodiments of the invention also provide an apparatus of routing convergence in a control plane of an intelligent optical network. According to the embodiments of the invention, the establishment of a new service or re-routing may be implemented within several seconds or even hundreds of milliseconds after the service link failure in the control plane occurs.

Abstract: Systems and methods for optical path protection for distributed antenna systems are provided. In one embodiment, a method is provided. The method comprises receiving an electrical uplink radio frequency signal; generating an uplink optical signal derived from the electrical uplink radio frequency signal; splitting the uplink optical signal for transmission on a primary uplink optical fiber and a secondary uplink optical fiber; combining any downlink optical signal received on a primary downlink optical communication medium and any downlink optical signal received on a second downlink optical communication medium in order to output a downlink optical signal; and generating a downlink radio frequency signal derived from the downlink optical signal.

Abstract: In a method and device which can quickly detect a fiber misconnection without setting an expected value, a node identifier of source node and an identifier of an interface for inputting/outputting a signal are set in a predetermined first field of a header to be transmitted to a destination node, and when both identifiers set in the first field are received from the destination node, both identifiers are set in a predetermined second field of the header to be transmitted and stored with the first field. When the identifiers set in the first and second fields are received and the identifiers of the second field among the identifiers are consistent with the identifiers of the first field stored at the second step (means), a connection is determined to be correct.

Abstract: Provided is a bidirectional wavelength division multiplexed passive optical network (WDM-PON) which includes a central office (CO) that transmits and receives multiplexed optical signals, a remote node (RN) that communicates with the CO, receives a multiplexed optical signal to demultiplex, and receives a demultiplexed optical signal to multiplex, an optical network unit (ONU) that transmits and receives demultiplexed optical signals to and from the RN, operational and protective backbone optical fibers that connect the CO to the RN, and operational and protective distribution optical fibers that connect the RN to the ONU.

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: 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.

Abstract: A network component is disclosed that includes a memory comprising a data structure comprising an optical network terminal management and control interface (OMCI) comprising a plurality of managed entities (MEs), wherein one of the MEs is a description of the OMCI. Also disclosed is a network component comprising a processor configured to implement a method comprising promoting the sending of an OMCI Description to an optical line terminal (OLT), wherein the OMCI Description comprises an OMCI Object, whose instance describes the types of MEs supported by an OMCI, a plurality of Managed Entity Objects, whose instances describe each ME supported by the OMCI, and a plurality of Attribute Objects, whose instances describe each attribute supported by the OMCI.

Abstract: An all-optical carrier sense multiple access collision detection apparatus and method for checking by using mutual gain saturation whether distortion occurs in two or more optical signals due to mutual interference when the optical signals pass through a semiconductor optical amplifier.

Abstract: An apparatus for performing an optical line analysis of continuous data signals. The apparatus comprise a phase position processor for computing a phase early/late indicator; a phase control code processor for computing a difference phase indicator; a frequency extractor for computing a low frequency jitter indicator; and a statistical calculator for computing a plurality of statistical measures regarding frequency and amplitude components of a jitter of an input continuous data signal, wherein the statistical measures are computed based on one of the phase early/late information indicator, the difference phase indicator, or the low frequency jitter indicator.

Abstract: 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.

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: An optical keyless entry sensor system and method includes an optical sensor in association with a mirror that reflects light transmitted from the optical sensor, wherein reflected light is detectable by the optical sensor. An attenuation filter can be located between the mirror and the optical sensor, wherein the attenuation filter is configured to simulate a contamination of the optical sensor in order to determine an exact level of attenuation representative of contamination that causes a performance failure of the optical sensor, thereby providing data which is indicative of a dynamic range of the optical sensor, such that the dynamic range is utilized to enhance the performance of the optical keyless entry sensor system.

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: An optical transmitting and receiving apparatus 1 has a transmitting circuit unit 20 including a light emitting element 2 and a driving circuit 3 which drives the light emitting element 2, a receiving circuit unit 30 including a light receiving element 5 and amplification circuit 6 which amplifies a signal received from the light receiving element 5, a judging unit 8 which judges an abnormality or failure of either or both of the transmitting circuit unit 20 and the receiving circuit unit 30 based on a measured data value provided from the transmitting circuit unit 20 and/or the receiving circuit unit 30, and a measured value storing unit 9 which stores the measure data value in the case that the judging unit 8 judges the abnormality or failure occurs in the transmitting circuit unit 20 and/or the receiving circuit unit 30.

Abstract: The present invention discloses a method for identifying an optical network unit (ONU) in an optical access system, including: receiving uplink signals sent by a plutality of ONUs through a shared optical transmission path; extracting detection signals from the uplink signals, and obtaining signal characteristics of the detection signals; and comparing the signal characteristics with a reference characteristic value, and determining, according to a result of the comparison, whether the multiple ONUs that send the uplink signals include a point-to-point connection-based (P2P) ONU. Through the method for identifying an ONU in an optical access system, when P2P ONU is mistakenly connected into a point-to-multipoint (P2MP) connection-based optical access system, a fault alarm can be raised quickly, which facilitates system maintenance and troubleshooting. The present invention further discloses an optical access system, an optical line terminal, and an optical module.

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: Component malfunctions in passive optical networks (PON) can increase bit error rates and decrease signal-to-noise ratio of communications signals. These faults may cause the receivers of the signals, either the optical line terminal (OLT) or optical network terminals (ONTs), to experience intermittent faults and/or may result in misinterpreted commands that disrupt other ONT's communication, resulting in a rogue ONT condition. Existing PON protocol detection methods may not detect these types of malfunctions. An embodiment of the present invention identifies faults in a PON by transmitting a test series of data patterns via an optical communications path from a first optical network node to a second optical network node. The test series is compared to an expected series of data patterns. An error rate may be calculated as a function of the differences between the test series and expected series. The error rate may be reported to identify faults in the PON.