Abstract: A WDM fiber optic communication system is operative to transmit WDM signals between multiple nodes. Each node has a booster EDFA, and in-band and out-of-band supervisory channels monitoring the integrity of a link by generating and detecting respective in-band and out-of-band control signals. The booster EDFA receives the multiplexed WDM and IB signals and generates an output signal carried by fibers between the nodes. The booster EDFA switches from an automatic gain control regime upon detecting of at least one of the IB and OB control signals to an automatic power control regime upon loss of both IB and OB control signals. The output signal of the EDFA in the AGC regime has a high power sufficient for transmitting the WDM and IB signals, and has a low power in the APC regime sufficient for transmitting only the IB control signal.

Abstract: A mechanism for adjusting or shutting off an optical signal within a network system is provided. The system may include a generating element for providing an optical signal and a bi-directional coupler for transmitting the optical signal to downstream components and fiber links and for transmitting a reflected optical signal based on the reflection characteristics of the downstream components to a converter element. The converter element converts the reflected optical signal to an electrical trigger signal that is used by a processing element to monitor the degradation or operational conditions within the network system. Based on the electrical trigger signal the processing element may adjust or shut off the optical signal at the generating element or at another element within the network system or another network system. The processing element may also send a communication signal to other elements or an operator to indicate unacceptable noise within the network system.

Abstract: The present invention provides an optical transmitter applicable to the WDM communication system. The optical transmitter includes a light-emitting device, an APC circuit and a processing unit. The processing unit, responding to a command TX_DISABL, which is sent from the control unit that communicates with the host controller, stops the optical output power of the transmitter by decreasing the reference to a preset value in step wise. Moreover, the processing unit, responding to a command ENABLE that is also sent from the control unit, starts the optical output by increasing the reference to another preset value in step wise.

Abstract: An optical network unit useful in a passive optical network has capability for automatic shutdown upon detection of a malfunction, thereby protecting the integrity of upstream data transmitted in the network. The unit detects the generation of upstream light during intervals in which transmission is not authorized. In response, the light source of the unit is deactivated to prevent collisions with upstream data from other optical network units in the network.

Abstract: Differently designed measuring systems exist of which most contain a central signal processing unit and a number of electrical measuring components, and in which the measured values furnished by the measuring components are optically transmitted over optical wave guides. The aim of the invention is to provide a measuring system of this type, which has low power consumption and enables a reliable optical data transmission. To this end, an optical loop is provided between a central measuring unit (MG) and a sensor head (SK). Microprocessors (MP1, MP2), which are situated inside the central measuring unit (MG) and inside the sensor head (SK), carry out transmitting, measuring and monitoring tasks as a distributed controller with bi-directional data communication. A frame synchronization signal serves both for supplying power as well as for deriving a clock signal for block-oriented data transmission.

Abstract: The invention concerns shutting down and restarting optical amplifiers, such as Raman amplifiers, in an optical link, depending whether the optical amplifier is a transmitting side amplifier or a receiving side amplifier. For controlling the amplifiers, at least one diagnostic signal is to be transmitted via an auxiliary optical channel in the optical link, and a number of physical events simultaneously taking place are to be taken into account to conclude whether to shut down or to restart one of the optical amplifiers.

Abstract: A fiber to copper patch terminal includes selectively activated circuitry for controlling an associated transceiver to produce a condition where normal communication with a connected power patch panel module has been temporarily interrupted. The patch terminal includes a selectively activated location identification function. This function when activated causes the optical transceiver to transmit a location signal preferably during a period where communication is awaiting resetting. In a preferred embodiment the patch terminal is designed to transmit the location signal during a period where Ethernet communication as awaiting completion of a reset.

Abstract: Embodiments related to light emitter control are described and depicted.

Abstract: A method and apparatus for fault notification in an optical network are described herein. In one embodiment, an exemplary process includes detecting at a node that at least a portion of a first unidirectional path of an optical circuit is down, where the first unidirectional path is originated from a first terminating node. In response to the detection, the node signals the first terminating node by removing at least a portion of light of a second unidirectional path in an opposite direction of the first unidirectional path of the optical circuit, to indicate a path between the node and the first terminating node is down. Other methods and apparatuses are also described.

Abstract: The invention relates to a package starting control device determining a moment and a sequence of starting a package corresponding to an individual wavelength to be wavelength-division-multiplexed in a wavelength division multiplex transmission device. An object of the invention is to provide a package starting control device capable of effectively increasing or decreasing the number of wavelengths at low cost without changing a basic structure drastically.

Abstract: The present invention provides an automatic power restoring method capable of reliably detecting continuity by the dissolution of a line fault, to restore the optical power, even in a structure including an optical amplification medium on an optical transmission path and an optical communication system using the method. To this end, in an optical communication system to which the automatic power restoring method of the invention is applied, a pilot signal having a low transmission rate, a wavelength of which is set based on loss wavelength characteristics obtained by combining loss wavelength characteristics of an optical fiber used for the optical transmission path and loss wavelength characteristics of the optical amplification medium on the optical transmission path, is transmitted and received between an optical transmitting station and an optical receiving station when a line fault occurs, and a detection of continuity is thus performed.

Abstract: A method and apparatus for initializing an end-to-end link in a fiber optic communications system in which a pair of nodes interconnect a pair of end devices. A first node, upon initializing a device link segment with an end device to which the node is coupled, sends a signal to the other node over a network link segment indicating that the sending node has initialized its device link segment. The first node completes initialization of the end-to-end link upon receiving a signal from the other node over the network link segment indicating that the other node has initialized its device link segment. In an alternative initialization scheme, a node momentarily operates its data channel in a loopback mode to allow its end device to initialize the device link segment in accordance with a predetermined protocol before returning to a transparent mode.

Abstract: Identification of optical channels in wavelength division multiplex (WDM) optical networks may be confounded by unwanted noise tones interfering with pilot/dither tones used for identifying optical channels. The invention describes a method of selecting pilot/dither tones that are selectively restricted to avoid allocating dither/pilot tone frequencies that appear as noise tones along the path of an optical channel in the optical network.

Abstract: A system, method, and computer readable medium for passive optical network rogue optical network unit diagnostics, comprises, detecting an alarm of a network, correlating the detected alarm to a bandwidth map, and selectively disabling an optical network unit upstream to the detected alarm on the bandwidth map for a pre-determined interval.

Abstract: The present invention discloses a method for handling channel failures in an Automatically Switched Optical Network (ASON). When a channel alarm occurs, the head service node decides whether the channel alarm is incurred by a channel failure according to the alarm message or alarm information. If so, the head and end service nodes continue to locate whether the channel failure is inside or outside the network by combining local detection and message notification. If the channel failure is an internal failure, rerouting is activated to locate and remove the channel failure. When this method is used to locate a channel failure, the amount of information exchanged is small. The method may quickly identify the accurate position of a failure inside the network, improve the efficiency in removing failures, and minimize the damages to services, with little harm to equipment functioning and network performance.

Abstract: A component for an optical communication network comprises a source (6) for an optical communication signal, an output port (11) for outputting the optical communication signal on an optical transmitting fiber (1), a light sensor (14; 15) and an optical circulator (9) for transmitting the optical communication signal from the source (6) to the output port (11) and for transmitting light reflected or received from outside at the output port (11) to the light sensor (14; 15). The light sensor (14, 15) has an evaluation circuit (13) connected to it for detecting a time delay between a time marker of a light signal from the source and the corresponding time marker of the light arriving at the light sensor (14; 15).

Abstract: A system is disclosed as including a power supply, a secondary capacitive storage device connected to the power supply, and multiple network devices powered by the power supply. The system further includes a designated device for transmitting a power loss condition over a network, where upon detection of an imminent interruption of power from the power supply the secondary capacitive storage device exclusively powers the designated device during transmission of the power loss condition, and the multiple network devices are intentionally powered off.

Abstract: The invention provides an optical shutter (400) for a communication system of a type comprising first (B1, B2) and second (A1, A2) communication paths along which information-bearing radiation propagates in opposite directions. The shutter (400) comprises: an optical tap (440) and a power monitor (430) for monitoring power of information-bearing radiation propagating along the first path (B1, B2) and for generating a corresponding radiation power indicative signal; a control unit (420) for comparing the indicative signal with a threshold value to generate a control signal (control); and shutter switch (410) for selectively substantially transmitting or blocking radiation propagating along the second path (A1, A2) in response to the control signal.

Abstract: The present disclosure relates to a passive optical network (PON) and discloses a method and system for maintaining the PON where the optical line terminal (OLT) is provided with an optical power detection module for measuring the total power of optical signals received by the PON, and the optical network units (ONUs) are provided with an optical transmitter power supply module.

Abstract: An optical transmitter system supplies a plurality of different wavelength optical radiation components to a transmission element which, in operation, is connected to the transmitter system for conveying the different wavelength radiation components to a respective receiver. The supply of the wavelength components is interrupted, preferably in response to a loss of the wavelength components at the respective receiver. A timer provides respective restart times which differ one to another for the wavelength radiation components. The supply of the wavelength components is restarted, following an interruption, at the respective restart times provided by the timer.

Abstract: The present invention provides an automatic power restoring method capable of reliably detecting continuity by the dissolution of a line fault, to restore the optical power, even in a structure including an optical amplification medium on an optical transmission path and an optical communication system using the method. To this end, in an optical communication system to which the automatic power restoring method of the invention is applied, a pilot signal having a low transmission rate, a wavelength of which is set based on loss wavelength characteristics obtained by combining loss wavelength characteristics of an optical fiber used for the optical transmission path and loss wavelength characteristics of the optical amplification medium on the optical transmission path, is transmitted and received between an optical transmitting station and an optical receiving station when a line fault occurs, and a detection of continuity is thus performed.

Abstract: A system for configuring fiber optic communication channels between arrays of emitters and detectors comprises: an array of light emitters; an array of light detectors; a bundle of optical fibers disposed between the arrays of light emitters and light detectors for conducting light from the light emitters to the light detectors, wherein the number of optical fibers in the bundle is greater than the number of light emitters in the array and wherein an area cross-section of the bundle of optical fibers overlaps the array of light emitters and the array of light detectors; and logic for mapping at least one emitter to at least one detector to establish at least one optical fiber communication channel between the array of light emitters and the array of light detectors. The system is further operative to monitor data communication over the at least one fiber optic communication channel and to reconfigure the mapping based on the monitored data communications thereof.

Abstract: A transmitter-receiver having a means for automatically determining the status of transmission medium such as optical fiber, and a means for automatically setting and resetting the transmission rate and/or output power according to the status of the transmission medium, a transmission loss and gain measurement method, and a transmitting-receiving system. A transmitter-receiver comprises at least: an output power controller for controlling the output power of a transmitter; an input power measuring section for measuring the strength of input signals; and an information processor for deriving the loss or gain of a path to change the output power of the transmitter and/or the rate of data transmission according to the derived loss or gain of the path.

Abstract: An optical transmission apparatus includes optical transmitters for transmitting optical signals and first monitor units for monitoring optical signals from the optical transmitters. A multiplexer is provided for multiplexing the optical signals from the optical transmitters into a multiplexed signal. A second monitor unit is provided for monitoring each optical signal which is multiplexed in the multiplexed signal from the multiplexer. A processing unit is provided for comparing a first number of optical signals detected by the first monitor units and a second number of optical signals detected by the second monitor unit.

Abstract: In an optical transmission node network in which a first optical transmission node is connected with a second optical transmission nodes through an optical fiber cable and automatic optical output (APSD: Automatic Power Shut-Down) control is activated, after the APSD control is brought into an inhibited status, if an optical conduction to the second optical transmission node is detected, the APSD control inhibited status is canceled. In this way, if an optical transmission fiber is resorted (reconnected) after optical output power measurement or the like is carried out, the APSD control inhibition status (invalid status) is canceled for automatically restoring the APSD control activated status. Thus, optical output can be prevented from being inadvertently emitted at a high energy level from the optical fiber cable.

Abstract: A method and apparatus for fault notification in an optical network are described herein. In one embodiment, an exemplary process includes detecting at a node that at least a portion of a first unidirectional path of an optical circuit is down, where the first unidirectional path is originated from a first terminating node. In response to the detection, the node signals the first terminating node by removing at least a portion of light of a second unidirectional path in an opposite direction of the first unidirectional path of the optical circuit, to indicate a path between the node and the first terminating node is down. Other methods and apparatuses are also described.

Abstract: Methods, systems, and computer-readable media provide for notifying an optical line termination (OLT) of a power failure. According to embodiments, a method for notifying an OLT of a power failure is provided. According to the method, a notification of a power failure at an optical network termination (ONT) is received. In response to receiving the notification, power is retrieved from a dedicated power storage unit dedicated to providing power for the transmission of a dying gasp alarm. The dying gasp alarm is transmitted to the OLT utilizing at least a portion of the power from the dedicated power storage unit. The dying gasp alarm notifies the OLT of the power failure.

Abstract: Disclosed is an optical cross connect apparatus that is applicable to an end office node and relay node in a path. The optical cross connect apparatus includes an optical switch for generating plural optical output signals from plural optical input signals; an optical level monitor section for detecting the optical levels of the optical input signals; and a control section that is connected to the optical switch and the optical level monitor section, includes a path switching management section for retaining a path switching management table, references the path switching management table when the optical input signals detected by the optical level monitor section are found to be OFF, and judges whether the optical switch should be operated.

Abstract: The present invention provides an automatic power restoring method capable of reliably detecting continuity by the dissolution of a line fault, to restore the optical power, even in a structure including an optical amplification medium on an optical transmission path and an optical communication system using the method. To this end, in an optical communication system to which the automatic power restoring method of the invention is applied, a pilot signal having a low transmission rate, a wavelength of which is set based on loss wavelength characteristics obtained by combining loss wavelength characteristics of an optical fiber used for the optical transmission path and loss wavelength characteristics of the optical amplification medium on the optical transmission path, is transmitted and received between an optical transmitting station and an optical receiving station when a line fault occurs, and a detection of continuity is thus performed.

Abstract: The present invention provides an optical signal transmission apparatus for carrying out bi-directional light transmission. The optical signal transmission apparatus includes: a light sending module, for sending an optical main-signal having at least one data width, and receiving an optical sub-signal including a control signal; a light receiving module for receiving the optical main-signal and sending the optical sub-signal; and an optical cable for connecting between the light sending module and the light receiving module, wherein the light sending module comprises a control component which controls the output of the optical main-signal such that the output of the optical main-signal is stopped, when the optical sub-signal, which includes as data the reception status of the optical main-signal, is not being received, or when the reception status of the optical main-signal is indicating non-receiving.

Abstract: An optimum optical node processor is provided to a metropolitan network in which the distance of a transmission line between each optical node processor is short. The optical node processor according to the invention is provided with an optical add/drop multiplexer (OADM), variable optical control means connected to the OADM for collectively attenuating the intensity level of WDM optical signals, a controller for controlling the variable optical control means and monitoring control means for controlling the controller according to information from an external device, and enables the automatic power reduction (APR) control and the output control of an optical network system.

Abstract: An optical transmission-path fault-detection system for detecting a fault in an optical-transmission path connecting an optical communications apparatus and an optical amplifier corresponding to the communications apparatus is disclosed.

Abstract: An optical network terminal, which includes an optical transmitter, monitors the status of the optical transmitter, such as the output or the power consumption of the optical transmitter, to determine when the optical transmitter is illegally transmitting. When an illegal transmission is detected, the optical network terminal removes power from the optical transmitter.

Abstract: An optical transponder, system, method, and program wherein the transponder monitors for at least one of a failure or an alarm signal. In response to detecting a failure or alarm signal (communication), the transponder performs at least one of a predetermined action and propagating an alarm communication to a network, based on a configuration property. The transponder can have a configuration property specifying a predetermined action for shutting off a laser if an alarm signal indicating a network failure is detected. As an example, some transponders can be configured to either provide an alarm communication, and/or shut off a laser, depending upon which communication interface detects a network failure or receives an alarm signal. Also, other transponders can be configured to propagate existing alarm communications, without generating new alarm communications or shutting off lasers.

Abstract: A transmission unit of a signal transmission device includes: a transmission-side detection unit that detects image information from an inputted electrical signal; a receiving unit that receives, from a reception unit, a status signal representing an arrival status of an outputted optical signal; and a control unit that controls an electrical-optical conversion unit on the basis of the detection result of the transmission-side detection unit and the status signal of the receiving unit so that the output of the optical signal is shut down in at least one of a case where image information is not included in an electrical signal and a case where an optical signal has not arrived.

Abstract: A method for powering up an optical network is provided. The method comprises remotely and safely increasing power to optical links in the optical network while monitoring signal levels in the network to discover installation errors, incorrect equipment configuration, and faulty components. In a modification to the method, attenuations of optical attenuators and gain values of optical amplifiers are set. The methods for powering up the optical network of the embodiments of the invention apply to both new optical networks and to new optical links added to pre-existing optical networks.

Abstract: An optical transmission equipment in an optical communication system interconnecting two optical transmission equipment sets by a main transmission line and a backup transmission line. An optical amplifier amplifies and outputs optical signals from one transmission line in use, interconnecting the optical transmission equipment concerned with neighboring upstream optical transmission equipment, and outputs the optical signals including a signal component and a noise component. A controller controls an optical signal level so that a signal component in the optical signal reaches a predetermined level.

Abstract: Embodiments of the present invention disclose a method for detecting an upstream timeslot conflict in a Passive Optical Network (PON). An Optical Line Terminal (OLT) detects a timeslot conflict in an upstream timeslot. An OLT is provided also, including an optical receiver, an optical transmitter, a control unit and a detection unit. The detection unit receives an optical signal from the optical receiver, samples instantaneous optical power of the optical signal in an upstream timeslot, compares the instantaneous optical power with normal upstream optical power of the upstream timeslot, and detects that a timeslot conflict occurs in the upstream timeslot when the instantaneous optical power exceeds normal upstream optical power of the upstream timeslot. Embodiments of the present invention make the costs lower to detect an upstream timeslot conflict in the PON.

Abstract: In an optical transmission apparatus in which a plurality of nodes are optically connected to one another via an optical transmission path, a light signal which is coded so that a mixture ratio of 1 and 0 constituting data is made close to 50% is transmitted through the optical transmission path. When a light signal is not emitted from all of the nodes, a dummy signal which is an AC-like signal is emitted to the optical transmission path. Therefore, an optoelectric conversion section can be always set to an active state, and the signal recognizability can be prevented from being lowered.

Abstract: A method for providing dying gasp support for a network component is disclosed. The method includes detecting an imminent loss of power to the network component and disabling all sub-systems of the network component except a designated sub-system of the network component upon the detection of the loss of power. The imminent failure of power to the network component is reported.

Abstract: A method for switching a transmission route in an optical network. A regenerator station extracts a main signal, and detects the input level of the main signal. When the input level falls below a threshold, the regenerator station determines that a failure occurs, and stops output of a main signal from the regenerator station, and transmits a control signal indicating occurrence of the failure to a receiver station, which separates the control signal from a main signal transmitted thereto, detects the input level of the main signal at the receiver station, analyzes the separated control signal, and determines whether or not a failure occurs. When the input level of the main signal at the receiver station falls below a threshold, or when the separated control signal indicates occurrence of a failure, the receiver station detects the occurrence of the failure, and switches the transmission route.

Abstract: Multiple working paths are established on each working rings and multiple protection paths are established on each of multiple protection rings. A working path on a first working ring spans across first and second nodes for signal transmission in a first direction of the ring, and a working path on a second working ring spans across the first and second nodes for signal transmission in a second, opposite direction of the ring. A protection path on a first protection ring spans across the first and second nodes for signal transmission in said second direction, and a protection path on a second protection ring spans across the first and second nodes for signal transmission in said first direction. The first and second nodes normally use the working paths, respectively. When one of the working paths fails, the first and second nodes use a corresponding protection path.

Abstract: A method for the automatic provisioning of a network element (NE) includes receiving a client signal at a tunable optical translator (OT) in the NE, determining the set of channels supported by the OT that are able to correspond to the client signal, eliminating the channels that have connections, that may be present on a line side of the NE in a laser off scan process, or that have not been equipped or otherwise provisioned for transmission, tuning the OT to each of the remaining channels and determining the optical power level of each channel on a line side of the NE in a laser on scan process. Subsequently, the channel with the highest power level is selected to transmit the client signal and associations for a point to point connection for that channel are added for that OT to a database of associations for the NE.

Abstract: The invention concerns a transmitter-receiver device (A, B) which comprises a receiver unit (RXA) arranged to receive light and optical signals from a transmitter unit (TXA) arranged to transmit light and optical signals. The device also comprises a supervising unit (CUA) which prevents the transmitter unit (TXA) from continuously transmitting light when the supervising unit (CUA) detects that the receiver unit (RXA) does not receive light. The supervising unit (CUA) is arranged to, when it detects that the receiver unit (RXA) does not receive light, change to a test mode where the transmitter unit (TXA) is controlled to intermittently transmit short light pulses the supervising unit has an output (109) where a status signal indicates whether the transmitter-receiver device is in said test mode. The invention also concerns a communication system which comprising at least two such transmitter-receiver devices.

Abstract: An optical communications system initiates automatic power reduction by selecting a portion of a Raman optical pumping signal from optical signals propagating on an optical fiber span. A signal related to a magnitude of the selected portion of the Raman optical pumping signal is generated. Power of at least one of the optical data signals and the optical pumping signals propagating in the optical fiber span is reduced in response to the generated signal.

Abstract: The invention concerns a transmitter-receiver device (A, B) which comprises a receiver unit (RXA) for receiving optical signals and transmitter unit (TXA) for transmitting optical signals. Furthermore, the transmitter-receiver device (A, B) comprises a supervising unit (CUA) which supervises the functions of the receiver unit (RXA) and the transmitter unit (TXA). Furthermore, the transmitter-receiver device (A, B) comprises a transmitter circuit which transmits optical communication signals in response to a balanced electric input signal. The invention also concerns a communication system comprising two transmitter-receiver devices (A, B). Through the structure of the invention is by relatively simple means a well functioning device achieved, which, inter alia, makes it possible to supervise the status of the two transmitter-receiver devices (A, B) in an advantageous manner.

Abstract: The present invention includes an optical transceiver having a fiber module with an optical data input and an electrical data output. The fiber module further includes a signal detect output that indicates the receipt of valid optical data. A physical layer device having a receive input is coupled to the electrical data output through a switch that is controlled by the signal detect output. The switch passes electrical data from the electrical data output of the fiber module to the receive input when the signal detect output indicates the receipt of valid optical data, and does not pass the electrical data when the signal detect output indicates invalid optical data. By using this configuration, the signal detects pins of the physical layer device are eliminated. In another embodiment, the switch is not utilized, and the electrical data output of the transceiver is ac-coupled to the differential receive input of the physical layer device.

Abstract: A circuit and associated method for safety shutdown of an optical amplifier, wherein the power of an amplified spontaneous emission ASE is subject to a correction factor and subtracted from a measured signal extracted from the optical signal.

Abstract: A transmission system is provided that recognizes occurrence of a fault efficiently so that the workability and quality of service can be improved. An optical amplifier part amplifies an optical main signal. A fault occurrence recognizing part detects a pump light used for an opposing device via an optical fiber transmission line to which an optical main signal is sent by the repeater. If the pump light is not detected, the fault occurrence recognizing part recognizes occurrence of a fault. A light cutoff control part stops the optical amplifying part outputting an amplified signal so that the light cutoff control in only one of two directions is performed when a fault occurs.

Abstract: Disclosed herein is a signal transmission method in a wavelength-division-multiplex (WDM) transmission system. The WDM transmission system comprises a first WDM terminal for transmitting a WDM signal, a second WDM terminal for receiving the WDM signal, and an optical add-drop multiplexer (OADM) node for transmitting to a network element an optical signal of a specific wavelength of the WDM signal which is transmitted between the first and second WDM terminals. The WDM signal is transmitted from the first WDM terminal to the second WDM terminal regardless of whether an optical signal is added or dropped at the OADM node. The network element employs an optical signal of an idle wavelength of the WDM signal that has no transmission data, to transmit another transmission data that is transmitted by the network element.