Abstract: Data center interconnections, which encompass WSCs as well as traditional data centers, have become both a bottleneck and a cost/power issue for cloud computing providers, cloud service providers and the users of the cloud generally. Fiber optic technologies already play critical roles in data center operations and will increasingly in the future. The goal is to move data as fast as possible with the lowest latency with the lowest cost and the smallest space consumption on the server blade and throughout the network.

Abstract: A system and method for performing an in-service optical time domain reflectometry test, an in-service insertion loss test, and an in-service optical frequency domain reflectometry test using a same wavelength as the network communications for point-to-point or point-to-multipoint optical fiber networks while maintaining continuity of network communications are disclosed.

Abstract: There are included: a light source (11) that outputs pulsed light; an optical splitter (12) that splits the pulsed light output from the light source (11) and outputs the split pulsed light from each of a plurality of second ports; a plurality of VOAs (13) that is each connected to a corresponding one of the second ports of the optical splitter (12), and attenuates and outputs the pulsed light input from the optical splitter (12); a plurality of optical couplers (14) each of whose first port is connected to output of a corresponding one of the VOAs (13) and each of whose second port is connected to one end of a corresponding one of a plurality of transmission lines (2) to be measured; a light receiving element (15) that receives backscattered light from the one end of each of the transmission lines (2); a power adjustment unit (16) that individually controls each of the VOAs (13); and a data processing unit (17) that performs abnormality detection on each of the transmission lines (2) from a result of light r

Abstract: The disclosed technology teaches testing a mesh network using new service application level KPIs that extend the TWAMP measurement architecture. A control-client receives and parses a configuration file to populate memory with IP addresses, ports, and test session parameters for disclosed KPIs used to originate two-way test sessions from a first network host; with control-servers and session-reflectors.

Abstract: The induction memory cell includes an electronic circuit that can control internally the “on” or “off” state of a magnetic field within a magnetic induction circuit. The induction memory cell can control external devices. When the induction memory cell is used in an array it can be programmed to retain binary information such as “on” as a binary digit of one or “off” as a binary digit of zero. The induction memory cell “on” or “off” state can be controlled via a one second burst of laser light, aim at one photo resistor for controlling the magnetic field “on” state in the primary coil or another photo resistor controlling the magnetic field “off” state in the primary coil. The induction memory cell requires a 1.5 volt, 5 amp power source in order to maintain an “on” or “off” switching effect in the primary coil.

Abstract: An optical transmission system comprises at least one first connection point and one second connection point arranged to transmit and receive at least one channel signal transmitted via at least one optical means connecting the first connection point and the second connection, wherein each of the at least one channel signal is reversibly configurable to be transmitted in either a first direction or a second direction between the first connection point and the second connection point. A method of transmitting at least one channel signal between a first connection point and a second connection point via at least one optical media in an optical transmission system, wherein each of the at least one channel signal is reversibly configurable to be transmitted in either a first direction or a second direction between the first and the second connection points.

Abstract: As network traffic grows and more data needs to be transmitted through a network, it is desired to use optical switching systems that allow for switching between a large number of nodes. An optical switching system according to one embodiment disclosed herein allows different nodes to transmit optical signals having the same optical wavelength, in order to accommodate a larger number of nodes. For example, one cluster of nodes may transmit data using optical wavelengths that are the same as optical wavelengths that may also be used by other clusters of nodes. A controller performs scheduling and reconfiguration in the optical switching system, as needed, e.g. in order to mitigate collisions.

Abstract: An optical transmission apparatus, includes: a reference-wavelength light source configured to generate reference light; a reference wavemeter configured to be calibrated by using the reference light; a receiver configured to receive measurement light transmitted from another optical transmission apparatus and wavelength information about the measurement light; and a controller, wherein the controller configured to: detect error between a first wavelength of the measurement light detected by using the reference wavemeter, and a second wavelength included in the wavelength information; and send error information that represents the error to the another optical transmission apparatus.

Abstract: Systems and methods are disclosed for data communication by forming a hybrid that includes an electrical switching network with packet granularity of switching and store-and-forward forwarding services to network traffic and an optical switching network providing circuit granularity of switching and optical bypassing services to network traffic; applying local control of optical switching modules in the optical switching network with a network controller coupled to the electrical switching network, the optical switching network, and a loss-of-light detection module; and detecting loss-of-light in a failure point in the optical switching network and rerouting traffic to avoid the optical failure point.

Abstract: A multi-failure resolution optical node includes an operating system wavelength path and two or more standby system wavelength paths which are assigned to the operating system wavelength path and have been assigned a ranking. It further includes a node control unit that can separately operate the operating system wavelength path and the standby system wavelength paths in a normal power consumption mode or a reduced power consumption mode. Thus, it is possible to provide an optical node with which power consumption is reduced and with which switching to a standby system wavelength path can be performed quickly in response to a failure in the operating system wavelength path.

Abstract: An optical branching/synthesizing device 20A includes an optical branching coupler group 25A and an optical combiner 26. The optical branching coupler group 25A includes a first-stage optical branching coupler 22 that receives a downstream optical signal Sd from an OLT device 12 at light input/output end 22a, and second-stage optical branching couplers 23 and 24 including light input/output ends 23b and 24a connected to light input/output ends 22c and 22d of the optical branching coupler 22 at the previous stage, respectively. A light input/output ends 23a, 23b, 24a, 24b of the optical branching couplers 23 and 24 transmit the downstream optical signal Sd to each ONU device 13 and receive upstream optical signals Su from the ONU devices 13. The optical combiner combines the upstream optical signals Su output from the light input/output ends 22b, 23a, and 24b of the optical branching couplers 22 to 24.

Abstract: In order to connect a path and a transponder with low loss, reduce an apparatus cost, reduce an apparatus size, and improve a reliability of an apparatus, a wavelength path multiplexing/demultiplexing apparatus comprises multiplexing/demultiplexing unit having a multiplexing port through which a wavelength multiplexed light is inputted and outputted and a demultiplexing port in which the wavelength multiplexed light is demultiplexed into the lights included in the wavelength multiplexed light based on the wavelength and through which the light is inputted and outputted and first switch unit which have a first port to which the demultiplexing port is connected and a second port and connect the second port to one of the first ports; and the demultiplexing port is connected to the first port of each of the first switch unit and the first port is connected to the demultiplexing port of each of the multiplexing/demultiplexing unit.

Abstract: A device may include a component, a first switch, a repeater, and a second switch. The component may configure optical paths between ports. The component may comprise a first pair of optical ports connected to a first pair of optical fibers, and a second pair of optical ports connected to a second pair of optical fibers. The first switch may be configured to output one of two optical signals received by the first pair of optical ports from the first pair of optical fibers. The repeater may reshape or amplify the outputted optical signal. The second switch may be configured to direct the reshaped or amplified signal to one of the second pair of optical ports.

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: A method includes generating a test signal and modulating the test signal. The method may also include transmitting the test signal on an optical path, where the optical path may include a number of add-drop multiplexer devices and amplifiers. The method may also include receiving the test signal at a destination device and converting the received test signal into an electrical signal. The method may further include identifying a portion of the electrical signal that is associated with the modulated test signal.

Abstract: A diagnostic testing utility is used to perform single link diagnostics tests including an electrical loopback test, an optical loopback test, a link traffic test, and a link distance measurement test. To perform the diagnostic tests, two ports at each end of a link are identified and then statically configured by a user. The ports will be configured as D_Ports and as such will be isolated from the fabric with no data traffic flowing through them. The ports will then be used to send test frames to perform the diagnostic tests.

Abstract: Methods and apparatus for a network element or server end station to determine an estimated physical location of a fault in a communications link utilized by two network elements. In an embodiment, the first and second network elements generate link failure indications including time values representing when the respective network element detected the fault. In other embodiments, the link failure indications include time values transmitted over the communications link between the first and second network elements. A time distance between these time values is calculated, which is used to calculate the estimated physical location of the fault. In some embodiments, the link failure indications include sequence numbers transmitted or about to be transmitted over the communications link between the network elements. Sequence distances are calculated between the sequence numbers, and are used to calculate the estimated physical location of the fault.

Abstract: A transmission apparatus includes a processor configured to recognize a number of working failures and a number of protection failures on a network for transmission of wavelength-multiplexed signal light, the number of working failures being the number of failures in signal light in wavelengths at a working entity and the number of protection failures being the number of failures in signal light in wavelengths at a protection entity, configured to perform path switching for each group of signal light in wavelengths that are different from each other and configured to select, when multiple failures occur, restoration processing, on a basis of the number of working failures and the number of protection failures.

Abstract: The present invention provides a method for processing a switch control command for solving the problem that consistency of data of the network device and the network management is unable to be kept in the process of processing the switch control command in the prior art. This method includes: when a priority of obtained trigger information is higher than a priority of a switch control command, discarding the switch control command (103); and reporting the discarded switch control command to a control system which manages the network device (104). The present invention further provides an device for processing a switch control command.

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

Abstract: Extender apparatus for an optical network includes first and second extender units having an network-facing port for connection to a backhaul fiber and a subscriber-facing port for connection to a feeder fiber. Each extender unit includes a gain assembly and is operable selectively either in an enabled state, in which the gain assembly amplifies a signal received at either port of the extender unit and couples it to the other port of the extender unit, or in a disabled state, in which the gain assembly blocks coupling of a signal from either port of the extender unit to the other port of the extender unit. A failover unit is operable when the first extender unit is in the enabled state and the second extender unit is in the disabled state to detect occurrence of at least one fault condition in the first extender unit. The failover unit is responsive to the fault condition in the first extender unit to switch the first extender unit to the disabled state and the second extender unit to the enabled state.

Abstract: An optical transmission apparatus includes an amplifier, a first output port to select a wavelength from the wavelength-division-multiplexed signal light amplified and output signal light with the selected wavelength to an operation line, a second output port to output multiplexed light obtained by multiplexing any one of first spontaneous emission light and second spontaneous emission light to a preliminary line, the first and the second spontaneous emission light being parts of spontaneous emission light generated by the amplifier, the first spontaneous emission light being in a wavelength range that is not selected, and the second spontaneous emission light being in a wavelength range other than a range of the wavelength-division-multiplexed signal light, and a judger to judge a continuity state of the operation line by using the signal light output to the operation line and a continuity state of the preliminary line.

Abstract: In one embodiment, an apparatus comprising an optical transmitter, having an optical transmitter portion and an electrical transmitter portion, and configured to convert an electrical signal to an optical signal, and transmit the optical signal; an optical receiver, having an optical receiver portion and an electrical receiver portion, configured to receive an optical signal and convert the optical signal to an electrical signal; a passive power controller configured to passively detect whether or not a cable is coupled with the optical transmitter and, if not, to place at least the optical transmitter portion in a sleep mode.

Abstract: A method for protecting a passive optical transmission network comprising an optical line terminal (OLT) at least one remote node (RN), and a plurality of network termination nodes (ONU) A bidirectional optical signal transmission can be established between each ONU and the OLT via a first bidirectional optical transmission route by means of which an optical wavelength-multiplexed signal is transmitted in the downstream direction from the OLT to the one or more RNs and in the upstream direction from the one or more RNs to the OLT. A second bidirectional optical transmission route is provided between the OLT and the RNs where the wavelength-multiplexed signal is fed in the upstream direction both to the first and second optical transmission routes. On the detection of a fault state on the first or second optical transmission route, the OLT is switched to the other corresponding optical transmission route.

Abstract: A SONET/SDH transmission apparatus comprises a plurality of interface units that accommodate a plurality of lines, and mesh wiring that interconnects the interface units in a mesh pattern. Each of the interface units includes a time slot interchange (TSI) unit to output a signal selected from among a plurality of signals through the TSI processing of a plurality of signals on the lines accommodated at all the interface units, a detection unit to detect alarm information on the lines accommodated at all the interface units, and a control unit to provide the TSI unit with control data reflecting protective switching operation calculated by computation of a logic circuit which virtually executes the protective switching operation to be as for the plurality of lines.

Abstract: A network protection switching mechanism comprises a plurality of optical switches located at a plurality of nodes; a plurality of optical communication paths between said switches; switch based fault detectors located as part of at least two switches which generate detection results representative of the identification of a fault; switch based controllers located as part of said at least two switches; and internal switch-communication means between said fault detectors and said controllers which facilitate the transmission of detection results from said fault detectors to said controllers; wherein said controllers directly cause switching to an alternative optical communication path dependent upon the receipt of said detection results; whereby autonomous switch based protection without dependence on either inter-switch control communication or higher level network control communication is achieved.

Abstract: A system and method of detecting polarity inversion in an optical switching circuit is disclosed. The method includes performing a first round of a port verification process on at least two optical ports, transmitting a payload from at least one optical port in the at least two optical ports, determining if the payload was received at a second optical port in the at least two optical ports, assigning a pair of ports to a first group in the case that the predetermined payload was communicated between the pair of ports, and assigning a pair of ports to a second group in the case that the predetermined payload was not communicated between the pair of ports. The method also includes determining that either the first group of ports or the second group of ports has inverted polarity.

Abstract: A system and method of detecting polarity inversion in an optical switching circuit is disclosed. The method includes performing a first round of a port verification process on at least two optical ports, transmitting a payload from at least one optical port in the at least two optical ports, determining if the payload was received at a second optical port in the at least two optical ports, assigning a pair of ports to a first group in the case that the predetermined payload was communicated between the pair of ports, and assigning a pair of ports to a second group in the case that the predetermined payload was not communicated between the pair of ports. The method also includes determining that either the first group of ports or the second group of ports has inverted polarity.

Abstract: A method is provided for protection switching in an optical network. The method may include establishing a baseline power level for a channel. The method may further include receiving a signal associated with the channel via each of a first path of the optical network and a second path of the optical network. The method may also include monitoring a power intensity of the signal received via the first path. The method may additionally include protection switching from the signal received via the first path to the signal received via the second path in response to a determination that the baseline power level exceeds the power intensity of the signal received via the first path by a predetermined threshold.

Abstract: The optical switch is capable of supervising the performance of optical switching in standby channels, and includes: a collimator unit; an optical splitter; a light-gathering unit; and a rotatable mirror. The optical switch further includes: a mirror angle controlling unit which controls a reflection face angle of the rotatable mirror for each wavelength to switch ON/OFF of the light beam coupling to the optical output port for each wavelength reflected, and determines an optical output port position outputting light beams of the reflected wavelengths; and a monitor unit, installed on a return path of a light beam, which monitors a light beam whose optical coupling is made OFF.

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

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

Abstract: A system and method is disclosed that allows for the monitoring, analyzing and reporting on performance, availability and quality of optical network paths. The correlation of PM parameter metrics to client connections, coupled with threshold-based alarm generation provides a proactive and predictive management, reporting and analyzing of the health and effectiveness of individual path connections to alert Operational Support (OS) staff and/or customers to signal degradation and impending Network Element (NE) failures. The system and method performs in real-time processing intervals required for alarm surveillance in a telecommunications network.

Abstract: In one embodiment, the present teachings provide for an efficient means to implement bidirectional data and signal channels in optical interconnects. Each optical interconnect channel may include two pairs of emitters and detectors that are imaged onto each other. Many such bidirectional optical channels may be simultaneously interconnected in dense two-dimensional arrays. The send or receive state of each bidirectional optical channel may be directly set in some embodiments by an electronic control signal. In other bidirectional optical channel embodiments, the send/receive state may be controlled locally and autonomously as derived from the output of the local detector.

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

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

Abstract: An apparatus, system and method are provided for a switchable fiber termination (SFT) incorporated into an optical network device that responds to a test signal received via an optical network carrying data. The test signal may be a part of a multiplexed signal carrying data and is separated from the data by a wavelength division multiplexer. The SFT may be used to determine the characteristics of an optical network, including the operational status of optical network devices.

Abstract: A method is provided for protection switching in an optical network.

Abstract: A client unit and a method are provided performing fault analysis in a Passive Optical Network, PON, by using Optical Time Domain Reflectometry, OTDR. The method comprises triggering a new OTDR measurement, wherein a previous reference measurement has been made indicating an original state of the PON. The method further comprises inserting an OTDR measurement signal into a multistage splitter before a last splitter stage of the multistage splitter, and wherein the last splitter stage is of ratio 2:N; and obtaining at least one new event location based on the OTDR measurement signal. Further, the method comprises calculating a fault magnitude at a given location by subtracting an event magnitude obtained from the new OTDR measurement from the reference OTDR measurement and taking into account the number of drop links connected to the last splitter stage in the reference measurement and the new measurement. Thereby, determination of position and severity of the fault locations is enabled.

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

Abstract: Provided is a multi-ring network operating method of cross-connecting at least two ring networks, the method including connecting an input working ring and an input protection ring of a ring network to an output working ring and an output protection ring of another ring network and then performing cross-connection between the same or different ring networks by using a multi-dimensional cross-connect apparatus. In the multi-ring operating method, a plurality of ring networks can be connected regardless of the protection method used by the ring networks, and the original protection method of each ring network can remain after they are connected.

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

Abstract: This invention discloses a method for mesh restoration, which includes the steps of: a) reserving channel resource for restoration path in the link by which the path passes and assigning discriminator for each channel, and determining the associated signaling channels for transporting the discriminator; b) when detecting the work path fails, activating the restoration path of the work path according to the discriminator which is transported by the associated signaling channel and whose value corresponds to a restoration. Using the method of the invention, the problem in rapid mesh restoration can be solved, and the speed of mesh restoration is comparable to that of the ring network protection.

Abstract: Disclosed is a method and node apparatus for traffic protection of Optical Transport Network (OTN), including: setting a part of channels in one fiber as working channels used for carrying traffic in need of protection, and setting a part of channels in the other fiber with a reverse transmission direction as protection channels, the number of which is equal to that of the working channels, to form a one-to-one protection for the working channels; when a failure in an optical line of OTN is detected, determining a bridging node and a switching node in accordance with pre-designated protection strategy, bridging and switching the traffic to be transmitted through the failed optical line between the working channels and the protection channels at the determined bridging node and switching node. This invention can realize OTN protection based on two-Fiber OMS shared protection ring, and improve the transmission reliability of optical networks.

Abstract: In one embodiment, a facilitating signal broadcasting includes receiving a first copy of a signal at a first selector of a first headend, where the first copy is received through a first receive pipe of a first ring. A second copy of the signal is received at the first selector, where the second copy is received through a second receive pipe of a second ring. The first selector selects either the first copy or the second copy. The selected copy is sent through a first transmit pipe of the first ring.

Abstract: A light source supplies optical signal to an optical switch and a detector detects light receiving level. A control unit changes a deflection control amount for changing an angle of a tilt mirror, and outputs the deflection control amount to a driving unit. When an input and an output ports are same, optical offset of the tilt mirror is calculated based on optimal angle at which the light detector detects an optimal point of the light receiving level. Whenever the input and the output port are different, a structure parameter of the tilt mirror is calculated based on the optical offset and the optimal angle. The optical offset and the structure parameter are stored in a memory as a test result.

Abstract: An optical network transmission channel failover switching device is proposed, which is designed for use in conjunction with an optical network for providing a transmission channel failover switching function, which is characterized by the provision of a two-to-two (2×2) type of optical switch, a one-to-two (1×2) type of optical switch, and a monitoring beam generating module for providing a backup channel monitoring function that can be used to activate the switching action. This feature allows the utilization of the optical network system to have enhanced reliability, serviceability, and security.

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

Abstract: The control of the transmission of useful optical signals on different line paths of an optical transmission device is accomplished via at least one of the following features: using signal sources and signal sinks, the useful optical signals are coupled into the line paths, or are coupled out of them; at least one portion of the optical line paths is configured as normal line paths having coupling nodes via which a switchover to an alternative line path can be undertaken if a normal line path is disturbed; in addition to the useful optical signals, test signals, whose evaluation is used for the switchover between the line paths, are transmitted bidirectionally section-by-section; at least two types of test signals can be transmitted, of which a first type is used as an indicator for an intact line path and a second type as an indicator for a disturbed line path; and any switchover to an alternative line path is only undertaken if, before the detection of the disturbance, a test signal of the first type has be