Abstract: In one example, an autonomy system assigns a trust level to a vehicle, wherein the trust level is a lowest trust level. The autonomy system may modify the trust level to fully autonomous in response to an indicator light providing a fully autonomous status prior to a maneuver as indicated by the indicator light. Additionally, the autonomy system may modify the trust level to driver controlled in response to the indicator light providing a driver controlled status prior to the maneuver as indicated by the indicator light.

Abstract: A machine learning apparatus includes: a state amount observation unit that observes a state amount of a laser apparatus including output data from an optical output detection unit, an optical output characteristic recording unit that records history of a driving current and optical output characteristics, and a driving condition/state amount recording unit that records history of a LD unit driving condition data and the state amount; an operation result acquisition unit that acquires a prediction result of characteristics and measurement result of optical output characteristics of the LD unit; a learning unit that learns the LD unit driving condition data with the state amount and the results of the LD unit driving condition data; and a decision-making unit that decides, from a learning result, the LD unit driving condition data.

Abstract: A transceiver can include a transmitter and a receiver. The transmitter can include: a primary laser emitter; a primary monitor photodiode optically coupled with the laser emitter; a spare laser emitter; and a transmitter integrated circuit having a primary channel operably coupled with the primary laser emitter; a spare channel operably coupled with the spare laser emitter; a switch on the primary channel; and a secondary channel operably coupled with the switch and the spare channel. The receiver can include: a primary detector photodiode; a spare detector photodiode; and a receiver integrated circuit a primary receiver channel operably coupled with the at least one primary detector photodiode; a spare receiver channel operably coupled with the spare detector photodiode; a receiver switch on the spare receiver channel; and a secondary receiver channel operably coupled with the receiver switch and the primary receiver channel.

Abstract: An illuminating light communication device comprises a constant current source, a smoothing capacitor connected to an output of the constant current source, a load circuit comprising a light emitting diode and connected to the output of the constant current source, a load change element added to the load circuit and thereby partially changing load characteristic of the load circuit, and a switch element configured to determine whether or not the load change element is added to the load circuit in accordance with a binary optical communication signal.

Abstract: An optical transmission device includes an extractor that extracts respective optical signals from optical signals multiplexed from a plurality of optical signals of different wavelengths, a detector that detects wavelengths of the extracted respective optical signals, a storage that stores the wavelengths of the detected respective optical signals, and a processor that is operative to derive trends in wavelength variation of the respective optical signals based on the detected respective optical signals and the respective optical signals stored in the storage, and determines that either one or both of the extractor and the detector cause the wavelengths to be varied when the trends in wavelength variation of two or more wavelengths are the same.

Abstract: A signature encoded light system includes at least one light source. The at least one light source is configured to output a first encoded light signature embedded within light in the visible spectrum. A light signature detection device is configured to receive a composite light signal formed with light from the at least one light source and ambient light. The light signature detection device is configured to identify the first encoded light signature.

Abstract: A method, an apparatus and a system for detecting a connection status of an optical fiber jumper are provided in the embodiments of the present invention. The method for detecting a connection status of an optical fiber jumper includes: judging a connection status of a second port and a first port according to whether an optical signal sent by the first port to the second port through a first optical fiber is received, wherein the first optical fiber is connected to two ends of an optical fiber jumper, and the two ends of the optical fiber jumper are connected to the first port and the second port respectively; and obtaining a port identification corresponding to the first port according to the optical signal if the optical signal is received.

Abstract: Methods, architectures, circuits, and/or systems for monitoring operating parameters and/or generating status indications associated with electronic device operation are disclosed. The method can include (i) monitoring a first operating parameter related to operation of the electronic device to determine a first parameter value, (ii) calculating a difference between the first parameter value and a predetermined value for the first operating parameter, (iii) monitoring a second operating parameter on which thresholds for operational warnings and/or alarms are based to determine a second parameter value, (iv) updating or changing the thresholds based on a predetermined change or event in the second parameter value, (v) comparing the difference to the updated or changed thresholds, and (vi) generating a corresponding one of the operational warnings and/or alarms when the difference crosses at least one of the thresholds in a predetermined direction.

Abstract: A wireless communications link comprising an RF link and a free space optics (FSO) link, a switch, an RF signal monitoring apparatus, an optical signal monitoring apparatus, alarm apparatus and a controller. The switch operates in a normal mode to aggregate the links to form a link aggregation group and to route traffic on the link aggregation group, a first protection mode to route traffic on the FSO link, or a second protection mode to route traffic on the RF link. The controller is arranged to receive an alarm signal and to generate and transmit a control signal to cause the switch to operate in the first protection mode when a first alarm signal is received, the second protection mode when a second alarm signal is received, and the normal mode when an indicator is received indicating that both signal quality parameters are above their threshold values.

Abstract: The optical transmission device includes an N×N optical switch, an optical packet receiver and an optical packet generation unit. The N×N optical switch transmits data in which a plurality of optical signals each having a different wavelength is multiplexed. The optical packet receiver detects change in the number of wavelengths of optical signals constituting the data. The optical packet generation unit generates, when the change is detected by the optical packet receiver, data to be transmitted by the N×N optical switch, using optical signals for the number of wavelengths after the change.

Abstract: Disclosed herein is an optical network terminal. The Optical Network Terminal (ONT) includes a laser diode for generating an optical signal to be transmitted to the OLT. A laser diode driving unit supplies driving current required for light emission of the laser diode. A driving current detection unit detects the driving current. A light emission time determination unit calculates a light emission time of the laser diode depending on a time for which the driving current is detected, and outputs a power control signal including information about results of a comparison between the light emission time of the laser diode and a preset reference time. A power supply voltage control unit interrupts a power supply voltage of the laser diode driving unit when the power control signal includes information indicating that the light emission time of the laser diode is longer than the reference time.

Abstract: A subscriber-side optical network unit (ONU) includes a control LSI for outputting a data signal and a pre-bias signal at fixed intervals, an optical transmitter-receiver for producing optical output in response to these signals, and a light-emission error preventing circuit for preventing light-emission error. First and second light-emission error detecting circuits output an abnormality detection alarm signal when no rising edge occurs in the data signal and pre-bias signal for a prescribed period of time. An OR element, when receiving the abnormality detection alarm signal from at least one of the first and second light-emission error detecting circuits, supplies the optical transmitter-receiver with a shutdown signal and halts the optical output.

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: An optical transmitting device includes: a laser diode to which a first or second driving current is provided; a controller to provide the laser diode with the first driving current to transmit an optical signal and with a plurality of second driving currents, to emit light, different from each other in magnitude during a stop of providing the first driving current; a measuring unit to measure an intensity of the light emitted by the laser diode; a calculator to calculate a threshold current of the laser diode, based on the intensities corresponding to the plurality of second driving currents measured by the measuring unit and magnitudes of the plurality of second driving currents; and a determination unit to determine a precursor of a sudden-death of the laser diode, based on an amount of variation in the threshold current calculated by the calculator during a specific period.

Abstract: Exemplary systems, devices, and methods for evaluating a link status of a fiber-optic communication system are disclosed. An exemplary transceiver device includes a transmitter configured to transmit an optical signal having a first wavelength to an additional transceiver device by way of a single optical fiber, a receiver configured to receive an optical signal having a second wavelength from the additional transceiver device by way of the single optical fiber, and a link status facility communicatively coupled to the transmitter and the receiver and configured to provide one or more visual indications of a link status between the transceiver device and the additional transceiver device. Corresponding systems, devices, and methods are also disclosed.

Abstract: An optical transceiver module adapted to a link device includes a connection unit, a driving unit and optical transmitting and receiving units. The connection unit, to be coupled with the link device, includes an indicating element for generating an indicating signal when the connection unit is coupled with the link device. The driving unit, coupled with the connection unit, receives the indicating signal and outputs a control signal according to the indicating signal. The optical transmitting unit, coupled with the driving unit, receives the control signal for driving the optical transmitting unit to output a first optical signal. The optical receiving unit, coupled with the driving unit, transmits a received second optical signal to the driving unit. An optical transmission device using the optical transceiver module, and an optical transmission method are also disclosed. A link training sequence can be initiated after the connection unit is actually coupled with the link device.

Abstract: An optical transmitter includes a plurality of VCSELs (vertical cavity surface emitting laser) that convert an electrical signal into an optical signal and transmit the converted optical signal. The optical transmitter measures a time for each of the VCSELs of transmitting an optical signal. Then, the optical transmitter assigns an electrical signal, indicating information to be transmitted, to one or more VCSELs, out of the VCSELs, other than a VCSEL of which a cumulative time measured is more than a predetermined threshold.

Abstract: The present invention relates to a fiber transmission field and provides a data sending or receiving method, device, and apparatus used in optical fiber transmission. The method includes: detecting data to be transmitted; encoding one bit pulse width to M parts if the to-be-transmitted data is 0, wherein the first part is a high-level, the later M?1 part is a low-level; encoding one bit pulse width to N parts if the to-be-transmitted data is 1, wherein the first part is a high level, and the later N?1 part is a low-level, the M is not equal to the N but both are integer which is greater than or equal to 2; and sending the encoded level signal.

Abstract: An optical transmission device includes a transmission unit, a filter unit, a detection unit, and a control unit. The transmission unit superimposes identical superimposition signals of a frequency modulation method on a plurality of optical signals that have identical destinations and that have adjacent wavelengths, and transmits resultant signals as one communication signal. The filter unit filters part of two optical signals having adjacent wavelengths from among the plurality of optical signals included in the communication signal. The detection unit generates an electric signal of a detection level representing an optical intensity of the two optical signals that were filtered by the filter unit. The control unit controls timings of superimposing the superimposition signals on the two optical signals respectively by controlling the transmission unit so that variation in the detection level becomes smaller.

Abstract: N optical transceivers are each connected to a respective electronic module in one-to-one relation such that a respective one electronic module controls a respective one optical transceiver. An electronic switch matrix provides cross-connect capability between the P redundant electronic modules and N electronic modules to the N optical transceivers. A system controller determines when an active N electronic module has failed, and configures the electronic switch matrix to switch a P redundant electronic module into the optical transceiver to which the failed electronic module was connected. A system switch module redirects traffic and routing information, under the direction of the system controller, from the failed module to the newly activated redundant module so that the redundant module assumes the functionality of the failed module.

Abstract: An optical communications system includes a MSAP and an optical transceiver mounted at the MSAP that communicates over an optical network to at least one optical network terminal (ONT). A first electronic module is operatively connected to the optical transceiver and configured to control the optical transceiver and mounted at the MSAP separate from the optical transceiver. A redundant second electronic module is supported within the MSAP and mounted separate from the optical transceiver. A Mux/Demux module interconnects and supports the first and second electronic modules to form an integral unit and mounted at the MSAP separate from the optical transceiver. The Mux/Demux module is configured to switch the second electronic module into communication with the optical transceiver upon failure of the first electronic module.

Abstract: The invention relates to a method of operating an optical transmission system (100a, 100b, 100c), wherein at least one optical data signal is transmitted over an optical transmission link (120), which particularly comprises at least one optical fiber (120a). The inventive method is characterized by modulating (200) said data signal with a test signal (s) having a predetermined modulation frequency fmod to obtain a modulated data signal (Pin), by receiving (210) a reflected portion (Pback) of said modulated data signal (Pin), and by determining (220) a fiber quality measure (a) depending on said received reflected portion (Pback) of said modulated signal (Pin).

Abstract: A method and system for protecting integrated optoelectronic devices are disclosed. The method includes (1) providing standby light source links of fixed wavelength and their corresponding standby data channel in a transmitting-end integrated optoelectronic device; (2) detecting whether there is failure in each active light source link in the transmitting-end integrated optoelectronic device; and (3) selecting a standby light source link having a fixed wavelength and its corresponding standby data channel for accomplishing service transmission of failed active light source link and its corresponding active data channel when detecting failure of an active light source link. The system includes a transmitting-end integrated optoelectronic device and a receiving-end integrated optoelectronic device.

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: 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: 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: 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: An optical signal division transmission system in which an input optical signal is divided into N parts (termed as “N-part optical signals”) and transmitted at a transmission rate of 1/N, wherein an additional optical wave path is provided separately from an optical wave paths for transmitting said N-part optical signals, and even if a malfunction occurs in any one of said optical wave paths for transmitting said N-part optical signals, transmission of said N-part optical signals is continued, using said additional optical wave path.

Abstract: A method for remote communication using the interpretation of thermoluminescence or photoluminescence signals uses a property of photoluminescence or of thermoluminescence when it is caused by entangled trapped electrons. In this case, stimulation of deexcitation of trapped electrons by heat or radiation occurs when the deexcitation thermal energy is approximately equal to the trap-emptying energy. Stimulation by a temperature rise of a “master” sample induces luminescence of a remote “slave” “entangled” sample, which is reproduced on lowering the temperature of the “master” sample whatever the distance and the media separating the “master” sample and the “slave” sample. This teaching and its generalization to other forms of stimulation is used by the method of interpreting the quantum reception measurements so as to determine, using a correlation method, the transmission of information or commands.

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: 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: 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: 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: 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 subscriber-side optical network unit (ONU) includes a control LSI for outputting a data signal and a pre-bias signal at fixed intervals, an optical transmitter-receiver for producing optical output in response to these signals, and a light-emission error preventing circuit for preventing light-emission error. First and second light-emission error detecting circuits output an abnormality detection alarm signal when no rising edge occurs in the data signal and pre-bias signal for a prescribed period of time. An OR element, when receiving the abnormality detection alarm signal from at least one of the first and second light-emission error detecting circuits, supplies the optical transmitter-receiver with a shutdown signal and halts the optical output.

Abstract: Methods and systems for an optical line termination including instructions stored on a computer-readable medium, the instructions including a digital diagnostic table, and a plurality of entries within the diagnostic table, wherein a first entry is associated with a first optical network unit, the first entry including at least one setting for performing burst mode digital diagnostic processes using a first burst mode transmission received from the first optical network unit.

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: 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: 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: Optical test apparatus. A test apparatus for testing transmitter or receiver devices. The test apparatus includes a transmitter source configured to connect to an optical transmitter. A wide band, wide area optical detector is adapted to optically couple to the optical transmitter powered by the transmitter source. A filter is connected to the optical detector. The filter is configured to separate AC and DC portions of a signal received from the optical detector. A true RMS converter is connected to the filter. The filter is configured to convert an AC noise signal received from the filter to a function of an RMS value of the AC noise signal received from the optical detector. A data acquisition system is connected to the true RMS converter. The data acquisition system is configured to characterize noise characteristics of the transmitter source.

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: An optical transmission system includes more optical channels than electrical channels. If an optical channel is not functioning, the signals may be diverted to another optical channel since there are more optical channels than electrical channels. Embodiments of the present invention also relate to switches for switching the electrical channels to particular optical channels on either or both of the transmission and reception side. The switches include switching elements and selector elements for routing the electrical signals between the electrical channels and optical channels. In one embodiment, the multiple optical channels are incorporated into a single cable. The single cable may have the electrical interface for a number of electrical channels exposed for mechanical and electrical coupling with an external port, whereas the optical channels may be hidden within the cable coating.

Abstract: In accordance with the teachings of the present invention, a system and method for managing wavelength drift in an optical network is provided. In a particular embodiment, the method includes receiving traffic in one or more optical channels transmitted by one or more transmitters, each channel having successive timeslots, each transmitter assigned to transmit in a channel in allocated timeslots in the channel. The method also includes determining whether the traffic received in a particular channel in a particular timeslot was transmitted by one of the transmitters that was not assigned to transmit in the particular channel.

Abstract: A fiber-optic communications interface (110) and method of operation that operates with a paired fiber-optic communications interface (112) in a redundant communications termination point (101). The fiber-optic communications interface (110) has a paired card interface (122) that exchanges at least a first subset of status data between a local bearer processor (124) and a paired bearer processor (144) located within a different card cage (112). The local bearer processor (124) processes bearer data channels communicating with a remote site (102) through a remote site fiber-optic line (106). A local data interface (128) exchanges data contained in the bearer data channels between the local bearer processor (124) and a local user data network (114). The local data interface (128) also exchanges at least a second subset of the status data with the paired bearer processor (144) through the local user data network (114).

Abstract: An optoelectronic device uses microcode to perform an end of life calculation for the optoelectronic device. In particular, the optoelectronic device senses environmental and operational parameters under changing conditions during device operation. The optoelectronic device then calculates the end of life for itself based on one or more of the sensed environmental and/or operational parameters. The calculation can be done in real time and using digital logic. The calculation can provide a result in a format which is useful to a host system with which the device is connected. The optoelectronic device may automatically shut itself down upon reaching its calculated end of life.

Abstract: Provided are an optical network terminal (ONT) and a method for the ONT to detect an optical transmission error. The ONT is connected with an optical line termination (OLT) and constituting a passive optical network (PON), and includes an optical transmitter configured to transmit an optical signal to the OLT, an error detector configured to detect an error of the optical transmitter; and a controller configured to transmit an error message to the OLT through the optical transmitter when the error detector detects an error of the optical transmitter.

Abstract: To detect a transmission path cut-off or deterioration depending on the presence or absence of receiving a packet signal at a fixed time interval without transferring an OAM packet. At a transmitting side, a conversion section periodically sends a main signal without including a maintenance operation signal packet. At a receiving side, a transmission path failure detection device judges that a transmission path failure is detected if it is determined that the next main signal is not received for a preset time after receiving the main signal. An OAM processing section detects a state where the main signal is not transmitted to the opposed transmission apparatus or an idle state, based on the detection of the transmission path failure by the transmission path failure detection device, and sends a maintenance operation signal for notifying the transmission path failure to the opposed transmission apparatus when in the idle state.

Abstract: A transmission apparatus switches to a line of one standby system upon occurrence of a fault on any one of n lines of a working system. The transmission apparatus includes a switching controller that when switching from a line of the working system to a line of the standby-system upon the occurrence of the fault and executing a given command to put the line causing the fault in a given state of line switching according to the given command, causes the working system to maintain the state of line switching according to the given command even after restoration from the fault.

Abstract: An optical transmission control circuit includes: an analog input section which receives optical transmission states as an analog values; an A/D conversion section which converts the analog values into digital values; a value storage section which stores maximum value of the digital values provided by the A/D conversion section; an output register which outputs a value to a host apparatus; and a control section which controls the maximum value storage section to store the maximum value of the digital values therein and controls the output register to output the maximum value to the host apparatus.

Abstract: Techniques for measuring optical modulation amplitude (OMA) are disclosed. For example, a technique for measuring an OMA value associated with an input signal includes the following steps/operations. The input signal is applied to a photodetector, wherein the photodetector is calibrated to have a given responsivity value R, and further wherein the photodetector generates an output signal in response to the input signal. The output signal from the photodetector is applied to a radio frequency (RF) power meter, wherein the RF power meter measures the root mean squared (RMS) power value of the output signal received from the photodetector. The OMA value associated with the input signal is determined in response to the root mean squared (RMS) power value measured by the RF power meter. The OMA value may be determined as a function of a factor F derived from a relationship between an amplitude of a data signal and the RMS value of the data signal.