Abstract: Systems and methods are implemented at an Optical Add/Drop Multiplexer (OADM) node using virtual sections to provide sectional control over an optical link over a foreign-controlled optical network. The systems and methods include obtaining and storing a first power spectral density snapshot of an optical link, from an optical spectrum monitor and when the optical link is in a non-fault condition; responsive to detection of a fault on channels traversing the optical link, obtaining a second power spectral density snapshot at a receiving end of the optical link; analyzing the first power spectral density snapshot and the second power spectral density snapshot; and determining the fault is on the optical link based on the analyzing.

Abstract: A wireless relay system includes a master unit and remote units. The remote units are connected to a communication path downstream of the master unit. Each remote unit includes a switching unit, a communication unit, a determiner, and a switching controller. The switching unit switches a normal connection in which the master unit or an upstream remote unit is connected to a downstream remote unit and a bypass connection in which they are connected with the communication unit not interposed therebetween. The communication unit processes a signal to be transmitted/received for communication. The determiner determines whether the communication unit is normal or abnormal. The switching controller switches the switching unit to the bypass connection when the communication unit is abnormal. After switching to the normal connection, the deter liner determines whether the communication unit is normal or abnormal after restarting the communication unit.

Abstract: The disclosed methods, apparatus, and systems allow safe and easy deployment of amplifier products that exceed laser safe limits without the need for fiber testing and characterization or OTDR techniques. One example embodiment is a method for ensuring eye safety in an optical network. The example method includes detecting optical connectivity between an output of a transmit amplifier and a passive optical processing element. The transmit amplifier is located at a first network node and is configured to output optical power greater than eye-safe level. The passive optical processing element is located at a second network node and is configured to guarantee a reduction of a maximum optical power level at an output side of the passive optical processing element to an eye-safe optical level. The detecting occurs at the first network node, and the transmit amplifier is enabled or disabled as a function of detection of the optical connectivity.

Abstract: An optical transceiver includes: a light source; a light source power management unit configured to manage a state of an output power of the light source; an optical detector configured to receive a first optical signal from a counterpart optical transmission apparatus and detect the first optical signal; and a monitoring information extraction unit configured to extract a monitoring information of a reception power level of a second optical signal, which is generated from an output light of the light source and received in the counterpart optical transmission apparatus, from the first optical signal, wherein the light source power management unit is configured to update a written value of the state of the output power of the light source in a case where a monitored value of the reception power level included in the monitoring information is decreased to exceed a variation of an optical transmission path.

Abstract: Safety and power control arrangement and method for optical communication apparatus, where a first circuit pack emitting an optical signal (OS1) and at least a second and a third circuit pack (2, 3) are connected in series via optical fibers (4, 5). A power monitor (26) connected to an output (27) of the at least second circuit pack (2) reduces the signal power (PW2) output from the second circuit pack (2) to a pre-determined safe value if a loss-of signal monitor (34) of a next circuit pack (3) forwards a loss-of-signal control signal (LOC3). The advantage is that the maximum allowable value is achieved at the input of an interrupted fiber section and the non-interrupted circuits can still receive the optical signals with a reasonable power level.

Abstract: A switch device can identify when a loss of signal event occurs on a communication link connecting a local link partner and a remote link partner. The switch device may automatically perform a link restart process to restore communication with the remote link partner without performing a speed negotiation with the remote link partner. The link restart process may include disabling a transmitter for a recovery duration and configuring a transmitter and a receiver to an initial configuration state. The link restart process may also synchronize the start of a training protocol communication between the local link partner and remote link partner. The switch device may also perform the link restart process when traffic received from the remote link partner fails a link criteria.

Abstract: A bus-based optical network system comprising optical fibers, optical line terminals (OLTs), and a plurality of optical network units (ONUs) is revealed. The OLT consists of the near part (OLTN) and the far part (OLTF). Optical fibers respectively form the transmitting and receiver buses (T Bus and R Bus) with the technique of time-division multiple access (TDMA). The slot flows on both buses are in opposite directions. The OLTN performing traffic control is situated in or near a central office (CO) while the OLTF is far from the CO. ONUs, whose MAC performs traffic control, connect with two buses and share their bandwidth. The MAC with traffic control keeps the performance of the network from degradation. The required numbers of COs and optical fibers for establishing the bus-based network are so smaller that the cost of the network can be significantly reduced.

Abstract: An optical transmission system includes a first node and a second node, the first node includes a first optical amplifier which outputs a signal to the second node through a first transmission line and a first monitoring unit, the second node includes a monitor which monitors a signal from the first transmission line, a second optical amplifier which outputs a signal to the first node through a second transmission line and a second monitoring unit, upon detecting disconnection from the first transmission line, the second monitoring unit transmits a notification for making power of the first optical amplifier reduced, upon receipt of the notification, the first monitoring unit reduces power of the first optical amplifier, and transmits a completion notification to the second monitoring unit, and upon not receiving the completion notification even after expiration of an allowed time, the second monitoring unit reduces power of the second optical amplifier.

Abstract: Node equipment 1, having optical attenuator unit 21 for optically attenuating wavelength division multiplexing signals received and optical multiplexer/demultiplexer unit 5 for performing optical multiplexing/demultiplexing of the wavelength division multiplexing signals received from the optical attenuator unit 21 via an optical cord 11, includes: output level detecting unit 24 for detecting the optical power level of the wavelength division multiplexing signals at a pre-stage of the optical cord 11; input level detecting unit 52 for detecting the optical power level of the wavelength division multiplexing signals at a post-stage of the optical cord 11; deciding unit 25 for deciding abnormality of the optical power level loss through the optical cord 11 from the optical power levels detected by the output level detecting unit 24 and input level detecting unit 52; and control unit 26 for controlling the optical attenuation of the optical attenuator unit 21 according to the abnormality decision result by the d

Abstract: A light receiving device includes: a converter digitalizing an analog signal with a given sampling clock frequency, the analog signal being obtained through a photoelectric conversion of a received optical signal; a plurality of fixed distortion compensators compensating an output signal of the converter for waveform distortion with a fixed compensation amount that is different from each other; a plurality of phase shift detector circuits detecting a sampling phase shift from an output signal of the plurality of the fixed distortion compensators; a phase-adjusting-amount determiner determining a sampling phase adjusting amount with use of an output signal of the plurality of the phase shift detector circuits; and a phase adjusting circuit reducing a phase difference between the sampling clock frequency and the received optical signal based on a determination result of the phase-adjusting-amount determiner.

Abstract: An optical transmission device according to the present invention comprises: a Raman amplification means; a main signal light sending means which sends first main signal light; a communication interruption detection light monitoring means which sends a first signal if it cannot detect communication interruption detection light; a main signal light monitoring means which sends a second signal if it cannot detect second main signal light; a light monitoring signal analysis means which sends a result of its analysis of a light monitoring signal as a third signal in a predetermined period of time; and a control means which makes the Raman amplification means suspend the generation of the excitation light, if it cannot receive the third signal even after the elapse of the predetermined period of time in the state it has received the first signal and has not received the second signal, and stops sending of the first main signal light from the main signal light sending means when receiving the second signal further.

Abstract: An optical network has an optical line termination coupled to a backbone network, in particular to an optical long haul network and a local exchange coupled to an optical access network. The local exchange provides an optical connection between an optical network unit of a tree topology and the optical line termination, which is part of a ring topology. There is also described a method for processing data in such an optical network.

Abstract: An eye safety mechanism for use with a bi-directional data cable having an electrical interface at at least one (but potentially both) ends, despite the fact that the cable communicates over much of its length using a bi-directional optical channel. Upon power-up, the eye safety mechanism determines whether or not a loss of signal condition is present on an optical receive channel of the bi-directional data cable. If the loss of signal is present, the mechanism intermittently disables the optical transmit channel of the bi-directional data cable. On the other hand, if the loss of signal is not present, the mechanism enables the optical transmit channel of the bi-directional data cable without intermittently disabling transmission at least for most of the time until the next time a loss of signal is detected on the optical receive channel.

Abstract: The internal propagation of radiation between a radiation source and radiation detector mounted within a sensor package is prevented by the use of an optical isolator. The optical isolator is formed by the combination of a baffle mounted between the source and detector and a groove formed in an upper surface of the sensor package between the source and detector. A bottom of the groove is positioned adjacent to an upper edge of the baffle.

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: Optical safety functions are incorporated into protection switching modules which maintain redundant pathways to avoid interruptions in optical network connections. The optical safety functions which lower optical power levels upon interruptions of optical connections are effectively combined with protection switching procedures which are also triggered by interruptions in optical network connections. The interoperation of protection and safety processes keep optical power levels below hazardous levels at system points which might be accessible to human operators.

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: The present invention includes method and apparatus for storing provisioned information within the optical switches and retrievable by every controller. The optical switches perform failure isolation according to their provisioning information. The optical switches monitor each channel for loss of signal. The provisioning information is shared autonomously between the optical switches allowing the switches to retrieve the provisioning information of the network topology from any other optical switch in the network. Fault isolation is done by the optical switch on the level of optical switch provisioning following the paradigm of “single alarm for single fault,” thus avoiding alarm floods and ambiguous alarms, thereby saving the operator time and money.

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: A power saving method in a passive optical network, including: when receiving an upstream burst timeslot allocated by the Optical Line Terminal (OLT) after a power supply of the Optical Network Unit (ONU) is turned off, the ONU dividing the upstream burst timeslot into one or more upstream burst timeslots; and the ONU turning on own laser in the upstream burst timeslot belonging to the ONU, and after sending one or more emergent Physical Layer Operations, Administration and Maintenance (PLOAM) messages to OLT in each upstream burst timeslot, promptly turning off the own laser. A power saving system in a passive optical network and an optical network unit is provided. The invention can decrease the power supply volume of an electric supply installation in a power-off ONU and reduce the cost of the electric supply installation.

Abstract: An optical amplifier of the present invention includes: an optical amplifier circuit that amplifies input signal light and outputs the amplified light as output signal light; a first monitor for monitoring the presence or absence of the input signal light; and a control circuit that, when receiving a shutdown control signal, controls the optical amplifier circuit such that a shutdown control speed for reducing a level of the output signal light to zero differs according to the presence or absence of the input signal light.

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

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

Abstract: The present invention provides an optical signal control method, an optical signal control system and an optical backplane system, which belongs to the field of optical communications technologies. The method includes: detecting whether a circuit board is pulled out from an optical backplane; if the circuit board is pulled out, querying a transmitting port of another circuit board connected to a slot where the pulled out circuit board is located, transmitting a first control instruction to the transmitting port, and notifying of closing the transmitting port or adjusting output power of the transmitting port to make it below a preset threshold. The optical signal control system includes: a detection module and a control module. The optical backplane system includes the optical signal control system.

Abstract: In case of a disconnection failure of an optical transmission line, a Raman amplifier generates a loss of main and supervisory signal alarms, an optical amplifier generates a loss of main signal alarm, and a supervisory signal transmission and reception unit detects the loss of supervisory signal. On the other hand, in case of a failure generated in an optical fiber, the supervisory signal transmission and reception unit performs APR control. Thus the optical amplifier stops outputting the main signal and continues to output the supervisory signal. The Raman amplifier generates the loss of main signal alarm, and the supervisory signal transmission and reception unit detects the loss of supervisory signal. The monitoring unit identifies failure point according to a combination of an existence of the loss of signal alarm by the Raman and optical amplifiers and the loss of supervisor signal by the supervisory signal transmission and reception unit.

Abstract: A method for engineering of a connection in a WDM photonic network with a plurality of flexibility sites connected by links comprises calculating a physical end-to-end route between a source node and a destination node and setting-up a communication path along this end-to-end route. An operational parameter of the communication path is continuously tested and compared with a test threshold. The path is declared established whenever the operational parameter is above the margin tolerance. The established path is continuously monitored by comparing the operational parameter with a maintenance threshold. A regenerator is switched into the path whenever the operational parameter is under the respective threshold, or another path is assigned to the respective connection. An adaptive channel power turn-on procedure provides for increasing gradually the power level of the transmitters in the path while measuring an error quantifier at the destination receiver until a preset error quantifier value is reached.

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

Abstract: An eye safety mechanism for use with a bi-directional data cable having an electrical interface at at least one (but potentially both) ends, despite the fact that the cable communicates over much of its length using a bi-directional optical channel. Upon power-up, the eye safety mechanism determines whether or not a loss of signal condition is present on an optical receive channel of the bi-directional data cable. If the loss of signal is present, the mechanism intermittently disables the optical transmit channel of the bi-directional data cable. On the other hand, if the loss of signal is not present, the mechanism enables the optical transmit channel of the bi-directional data cable without intermittently disabling transmission at least for most of the time until the next time a loss of signal is detected on the optical receive channel.

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 communication serial interface is employed to power up a device from a powered down state to a powered on state. An optical receiver element receives serial optical signals transmitted by at least one optical fiber and converts the received serial optical signals to electrical signals. A low level reception converter detects and decodes the electrical signals to provide data and control words from detected and decoded normal electrical signals for a high level command processor. A power supply maintains low level power to at least the optical receiver element and the low level reception converter of the optical communication serial interface while the device is in the powered down state. The low level reception converter detects a particular abnormal sequence of electrical signals; and in response to detecting the particular abnormal sequence of electrical signals, asserts a control signal to power up the device controllable power supply.

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: The present invention relates to the quality monitoring of optical signals, which have different symbol rates and generated by different modulation schemes, used for example in a wavelength division multiplexing network. The apparatus according to the invention includes an optical splitter for outputting the input optical signal to a first optical route and a second optical route, an optical coupler for coupling a optical signal from the first optical route with a optical signal from the second optical route, a delay unit provided on the first optical route, and a phase shift unit provided on the first optical route or the second optical route.

Abstract: The present relates to pluggable electronic unit with transmission power adjustment capability such as for example small form-factor pluggable transceivers. The pluggable electronic unit with transmission power adjustment capability may comprise a power adjustment unit. By verifying the transmitted power is sufficient or could be reduced, it is possible to regulate transmission power of a transceiver autonomously within the pluggable electronic unit itself.

Abstract: An eye safety mechanism for use with a bi-directional data cable having an electrical interface at least one (but potentially both) ends, despite the fact that the cable communicates over much of its length using a bi-directional optical channel. Upon power-up, the eye safety mechanism determines whether or not a loss of signal condition is present on an optical receive channel of the bi-directional data cable. If the loss of signal is present, the mechanism intermittently disables the optical transmit channel of the bi-directional data cable. On the other hand, if the loss of signal is not present, the mechanism enables the optical transmit channel of the bi-directional data cable without intermittently disabling transmission at least for most of the time until the next time a loss of signal is detected on the optical receive channel.

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

Abstract: According to halt of a Raman pumping light source, a transmitting light power of a first light which is subject to receive a Raman gain is controlled to increase. In this state, a first input/output light power for a first light of an optical transmission line is measured, the first input/output light power being used for determining a reference of loss characteristic of the optical transmission line. A second input/output light power for a second light of the optical transmission line is measured, the second light not being subject to receive the Raman gain, the second input/output light power being used for determining a fluctuation of the reference.

Abstract: An optical wavelength multiplexing system includes transmission-side and reception-side optical wavelength multiplexers, and terminal devices, which are connected to each other by optical fiber cables. Optical wavelength converters in the transmission-side optical wavelength multiplexers are connected to ports respectively. The optical wavelength converter converts an input optical signal into an arbitrary preset wavelength to generate a converted optical signal. The port has a predetermined wavelength preset therein. Each optical power level of input converted optical signals is compared with each optical power level of optical signals of respective wavelengths set in the ports. When a difference is detected in the comparison result, it is determined that an optical wavelength converter is incorrectly connected to the port.

Abstract: An input of a command to stop optical output or a command to reduce optical output by a main signal transmitting section is received from the outside. When the input of the optical output stop command or optical output reduction command is received, an inter-device control signal communication section transmits the optical output stop command or optical output reduction command. Based on the input optical output stop command or optical output reduction command, an output of optical signals from the main signal transmitting section is stopped, or else the output level is reduced to less than the output level during normal operation.

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

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

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

Abstract: A method is provided including the steps of monitoring at least one performance metric of at least one network component in an optical network system, determining whether the at least one network component is a rogue network component using the at least one performance metric, saving environment data to a non-volatile storage medium, and modifying the operation of the rogue network component to reduce interference of the rogue network component with the optical network system. In another embodiment, a method includes detecting a condition of a network component in an optical network system, and writing environment data of the network component to a non-volatile storage medium.

Abstract: An abnormal pulse detection circuit in a receiver of the present invention includes: an incoming pulse edge detection circuit which detects the moment of rise of an input signal and outputs the result of the detection as an edge detection signal; a muting reference pulse generation circuit which generates a muting reference pulse based on the edge detection signal; a logic circuit which outputs a signal indicating a negative AND of the muting reference pulse and the input signal; a muting signal generation circuit which generates a muting signal from the output signal of the logic circuit; and a switching circuit which outputs the input signal or the muting signal. The receiver of the present invention can therefore reduce discomfort in hearing reproduced sound in case where a noise occurs in an audio signal due to a variation in pulse width.

Abstract: To control activation of one or more communication units in a survey system that performs surveying of a subterranean structure, optical activity on at least one optical link connected to at least one communication unit that is part of a survey system is detected. In response to determining that the optical activity has a characteristic that satisfies a predetermined criterion, the at least one communication unit is awakened.

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: A method and apparatus for controlling the power level of an optical signal includes detecting the loss of a supervisory signal counter-propagating in an optical fiber.

Abstract: A method for engineering of a connection in a WDM photonic network with a plurality of flexibility sites connected by links comprises calculating a physical end-to-end route between a source node and a destination node and setting-up a communication path along this end-to-end route. An operational parameter of the communication path is continuously tested and compared with a test threshold. The path is declared established whenever the operational parameter is above the margin tolerance. The established path is continuously monitored by comparing the operational parameter with a maintenance threshold. A regenerator is switched into the path whenever the operational parameter is under the respective threshold, or another path is assigned to the respective connection. An adaptive channel power turn-on procedure provides for increasing gradually the power level of the transmitters in the path while measuring an error quantifier at the destination receiver until a preset error quantifier value is reached.

Abstract: The present invention allows immediate reading of a monitor voltage of a required arbitrary burst cell and provides a burst light receiving power monitor circuit that monitors the monitor voltage of a burst cell, the burst light receiving power monitor circuit comprising: a memory that includes a plurality of areas and that prepares an address for each area; a monitor voltage forming section that converts input signal light of the burst cell to a digital monitor voltage amplitude; and a controller that continuously stores the monitor voltage amplitude from the monitor voltage forming section in each area of the memory specified with an address by a control signal externally inputted according to the timing of the burst cell and that controls reading out a monitor voltage from an arbitrary area of the memory specified with an address by an external memory access signal.