Abstract: An optical node (100) for multiplexing optical signals is disclosed. The optical node (100) comprises an add port (102), a common port (104), an auxiliary port (106), an optical transfer module (110), and a reflecting element (108) coupled to the auxiliary port. The optical transfer module (110) is configured to couple a signal received on the add port (102) and matching an operational wavelength of the optical node (100) to the common port (104), and to couple a signal received on the add port (102) and not matching an operational wavelength of the optical node (100) to the auxiliary port (106). The reflecting element (108) is configured to reflect a signal received on the auxiliary port (106) to the add port (102). Also disclosed are an optical transceiver and methods for operating and optical node and an optical transceiver.

Abstract: A communication system of a passive optical communication network includes an optical line terminal (OLT) system including a first OLT, a second OLT, and an OLT control device that controls the first OLT and the second OLT, a plurality of splitters that connects between the first OLT and the second OLT with an optical communication path, and an optical network unit (ONU) that is connected to each of the plurality of splitters with an optical communication path.

Abstract: Systems and methods are provided for improving signal propagation using lasers. A laser device is used to clear the air between a first fixed station, such as a base station, and a second fixed station, such as a fixed wireless access device. In the wake of the laser, particles in the air interface are cleared along a path that can then be used to communicate one or more sets of wireless signals. In the wake of the laser, the wireless signals experience less absorption, reflection, and refraction, reducing path loss, and increasing the overall effectiveness of the wireless system—particularly at or near the cell edge or when a meteorological condition exists between the fixed stations.

Abstract: Embodiments of the invention describe flexible (i.e., elastic) data center architectures capable of meeting exascale, while maintaining low latency and using reasonable sizes of electronic packet switches, through the use of optical circuit switches such as optical time, wavelength, waveband and space circuit switching technologies. This flexible architecture enables the reconfigurability of the interconnectivity of servers and storage devices within a data center to respond to the number, size, type and duration of the various applications being requested at any given point in time.

Abstract: Systems, methods, and devices for offloading network data to a datastore. A system includes routing chip hardware and an asynchronous object manager in communication with the routing chip hardware. The asynchronous object manager is configurable to execute instructions stored in non-transitory computer readable storage media. The instructions include asynchronously receiving a plurality of objects from one or more producers. The instructions include identifying one or more dependencies between two or more of the plurality of objects. The instructions include reordering the plurality of objects according to the one or more dependencies. The instructions include determining whether the one or more dependencies is resolve. The instructions include, in response to determining the one or more dependencies is resolved, calling back an application and providing one or more of the plurality of objects to the application.

Abstract: A wiring information creation system includes a switching device that switches a transmission path of an optical signal between an upper network and a lower network in units of combinations of physical ports, a switching control device that outputs, to the switching device, an instruction for switching the transmission path such that the transmission path passes through a selected physical port, a connection control device that determines whether a communication port of an intermediate communication device that relays communication between the upper network and the lower network and the selected physical port have been connected to each other and acquires, from the intermediate communication device, a number of the communication port connected to the selected physical port, and an information creation device that creates connection information indicating the communication port connected to the selected physical port and updates wiring information indicating connection information for each physical port of the

Abstract: Methods, systems, and devices are provided herein for providing a visually guided topology wiring scheme. As described herein, after determining that a first end of a cable has been inserted at a first port of a first peer device, a wiring application may reference a topology file to identify a second port of a second peer device with which the first peer device is intended to have a link. Subsequently, the wiring application may activate an indicator associated with the second port to mimic an indicator associated with the first port. For example, the wiring application may cause both indicators associated with each port to flash according to a same or similar flashing pattern, to produce or illuminate at a similar or identical color (e.g., approximately the same color), to flash at approximately a same rate, or by substantially synchronizing a flashing of each indicator.

Abstract: Embodiments of the present invention transmit fragmented frames using a sequence control field in a MAC header that includes an extended 15-bit sequence number for tracking the order of frames, and a 1-bit PF field that indicates the position of a fragmented frame in conjunction with a 1-bit MF field carried in a frame control subfield of the MAC header. The fragmented frames can be received by a wireless device and defragmented according to the MF field, the PF field, and the sequence control number. The frames can be discarded if any are not received successfully.

Abstract: A method includes: determining, by the control device, that a site receives a first service; determining that a mapping wavelength of a first service is blocked on an original routing path, where the original routing path includes a first line board connected to a first local dimension, and a wavelength occupied by the first local dimension includes the mapping wavelength of the first service; and routing, by the control device, the first service to a second line board connected to a second local dimension, where the mapping wavelength of the first service is available in the second local dimension.

Abstract: Systems and methods for automated network cabling integrity monitoring are provided. In one embodiment a system manager for a network that includes a network switch coupled to patching equipment comprises: at least one processor configured to execute software, the software comprising a network integrity monitor. The network integrity monitor controls a cable diagnostic test function to obtain a fault-distance measurement for a port of the switch. The network integrity monitor correlates the fault-distance measurement with network cable length information associated with the switch port to identify one or both of a network cable segment associated with the fault-distance measurement and a fault location. The cable length information is retrieved from a database. The network integrity monitor produces an output identifying of one or both of the network cable segment associated with the fault-distance measurement and the fault location to be displayed on a display device.

Abstract: An electrical circuit package includes an electrical processing engine circuit configured to perform data processing; and one or more co-packaged coherent optical Input/Output (IO) modules interconnected to the electrical processing engine circuit, wherein the electrical processing engine circuit is configured to interface electrical data including an optical signal waveform representation to each of the one or more co-packaged coherent optical IO modules, and wherein the one or more co-packaged coherent optical IO modules are configured to coherently transmit and receive optical data based on the optical signal waveform representation. The electrical processing engine circuit can be configured to perform optical modulation and demodulation based on the optical signal waveform representation, in addition to the data processing.

Abstract: An optical module includes a photoelectric converter configured to receive an optical signal having an intensity that changes at one of a first frequency or a second frequency that is higher than the first frequency, and convert the optical signal into a current signal corresponding to the intensity of the optical signal; a signal processor configured to acquire, when the optical signal has the intensity that changes at the first frequency, wavelength information set on a transmitting side based on a ratio between a plurality of signal intensities included in the current signal relating to the optical signal having the intensity that changes at the first frequency; and a decoder configured to generate, when the optical signal has the intensity that changes at the second frequency, communication data from the current signal relating to the optical signal having the intensity that changes at the second frequency.

Abstract: An optical device having a self-repair component capable of curing a defective component(s) is disclosed. To improve reliability as well as manufacturing yield, a photonic integrated circuit (“PIC”) for as a multi-channel optical line terminal (“OLT”) contains spare lasers or standby lasers configured to replace a failed laser(s). In one aspect, PIC includes a set of fixed-wavelength lasers (“FWLs”), a tunable-wavelength auxiliary laser (“TWAL”), a photonic detector, and a tuner. FWLs, for example, generate optical wavelengths representing optical signals. TWAL generates an optical signal with a spectrum of wavelengths based on a setting generated by the tuner. The photonic detector detects a defective wavelength. The tuner adjusts output wavelength of TWAL in response to the defective wavelength. Alternatively, PIC includes a working laser array, standby laser array, and spare laser array capable of providing two-layer laser defective protections.

Abstract: A system for transferring data between a rotating element and a fixed element by wireless optical communication, including a plurality of rotating optical transmitters distributed in a ring around the turning element and solidly attached to the rotating element, and at least one fixed optical receiver mounted on and solidly attached to the fixed element, arranged at the same height as the plurality of rotating optical transmitters in which the rotating optical transmitters simultaneously transmit a same optical signal, independently of the angular position of the rotating element and are sufficiently numerous such that regardless of the angular position of the rotating element, the fixed optical receiver receives an optical signal.

Abstract: An optical device having a self-repair component capable of curing a defective component(s) is disclosed. To improve reliability as well as manufacturing yield, a photonic integrated circuit (“PIC”) for as a multi-channel optical line terminal (“OLT”) contains spare lasers or standby lasers configured to replace a failed laser(s). In one aspect, PIC includes a set of fixed-wavelength lasers (“FWLs”), a tunable-wavelength auxiliary laser (“TWAL”), a photonic detector, and a tuner. FWLs, for example, generate optical wavelengths representing optical signals. TWAL generates an optical signal with a spectrum of wavelengths based on a setting generated by the tuner. The photonic detector detects a defective wavelength. The tuner adjusts output wavelength of TWAL in response to the defective wavelength. Alternatively, PIC includes a working laser array, standby laser array, and spare laser array capable of providing two-layer laser defective protections.

Abstract: Example embodiments of the present invention relate to a software programmable reconfigurable optical add drop multiplexer (ROADM) comprising of at least one M×N wavelength selective switch and a plurality of programmable waveguide optical elements, wherein when the plurality of programmable waveguide optical elements are set to a first configuration, the software programmable ROADM provides wavelength switching for at least two degrees of an n-degree optical node, and wherein when the programmable waveguide optical elements are set to a second configuration, the software programmable ROADM provides wavelength switching for at least two degrees of an m-degree optical node, wherein m>n.

Abstract: Methods and systems for optical data unit (ODU) path protection in a disaggregated optical transport network (OTN) switching system that include using plug-in universal (PIU) modules each having multiple ports for OTN to Ethernet transceiving and an Ethernet fabric as a switching core are disclosed. An OTN over Ethernet module in each of the PIU modules may enable various OTN functionality to be realized using the Ethernet fabric which may include multiple Ethernet switches. An egress PIU module may receive Ethernet packets via the Ethernet fabric from a working ODU path. In response to determining that a protection switch using a protection ODU path may be performed on the working ODU path, the egress PIU module may receive the Ethernet packets via the Ethernet fabric from the protection ODU path.

Abstract: Methods and systems are disclosed for storing, in a non-transitory memory device, multi-layer network information comprising at least one of link availability, bandwidth availability, priority levels for paths in a multi-layer network, path status in the multi-layer network, and status for network elements in the multi-layer network; receiving, via at least one input component, a message from a network element in the network comprising information indicative of a failure of a working path in the network; determining, automatically, based at least in part on the multi-layer network information, an alternate path for transmission of the data traffic through the network; and transmitting, via at least one output component, at least one signal comprising configuration instructions to at least one optical line module, the configuration instructions directing the optical line module to switch and select the data traffic using the alternate path.

Abstract: A datacenter for performing a service is provided. The datacenter is configured for receiving an optical signal comprising groups of wavelength bands, A1, A2, A3, . . . , AX, and B, X being an integer, the signal being associated with a request for a service to be executed by the datacenter, the datacenter being configured for executing the service and outputting the result of the service. The datacenter comprises at least one 1:N MD-WSS, having one common port and N tributary ports, where N is an integer and N>1, and a group of at least one server cluster, each comprising a respective transceiver configured to receive and transmit signals on at least some of the wavelength bands.

Abstract: The present invention provides a protection switching method of a node having communication failure in a ring, in a communication network. In one embodiment, this is accomplished by checking for loss of signal (LOS) at the non-ERPS device or at least one of the node in a communication channel, checking periodically for Continuity Check Message (CCM) at both the node, wherein the CCMs are periodically transmitted from both the node through at least one non-ERPS device, appropriately setting a Remote Destination Indication (RDI) bit in the Continuity Check Message (CCM) generated from at least one node and transmits the same via the non-ERPS device or through the non-ERPS device or through a disjoint communication channel, and blocking port of the node towards the non-ERPS device upon receipt of the fault notification and transmitting signal fail notification message on both the ports in the ring.

Abstract: A first and second head-end terminal and at least one optical add/drop filter device are connected to form a transmission path. Each head-end terminal is connected through an optical fiber to a western or eastern WDM port of an adjacent optical add/drop filter device, and each optical add/drop filter device is connected, at an eastern or western WDM port, to a western or eastern WDM port of an adjacent optical add/drop filter device. At least one tail-end terminal is connected to each optical add/drop filter device, wherein a first and second channel port of the respective add/drop tail-end terminal is connected to a dedicated first and second channel port of the optical add/drop filter device through a respective optical fiber. The head-end terminals, the optical add/drop filter devices, and the tail-end terminals are adapted to establish bidirectional communication between each tail-end terminal and the first and second head-end terminal.

Abstract: A method and a device for realizing an optical channel data unit (ODU) shared protection ring (SPRing) are disclosed by the present invention. The method includes: A first ODU of a first service transmitted in an optical line is taken as a protection granularity, where the first ODU is an ODUk that is directly multiplexed to the optical line; the first ODU is monitored, and a monitoring result is obtained; when the monitoring result indicates that a failure occurs, a switching is performed through cross of a second ODU of the first service, where the second ODU is an ODUm that is multiplexed to the first ODU, and m is smaller than or equal to k. Through the embodiments of the present invention, a protection switching speed may be accelerated.

Abstract: The disclosure relates to a method and apparatus for implementing self-adaption of cross granularity in an Optical Transport Network (OTN). The method includes: acquiring an optical interface side OTN service signal which has been processed by a frame-forming chip, and performing determination on the frame header of an Optical channel Data Unit (ODU) frame of the current level in the OTN service signal; when frame-alignment is determined to be successful, performing level-by-level de-multiplexing processing on the ODU frame of the current level to obtain cross granularities of different levels, selecting output channels for the cross granularities of different levels, performing mapping processing on the output cross granularities of different levels to form fixed rate service signals, and outputting the fixed rate service signals to back board ports, where the signals are transmitted to a cross board.

Abstract: Embodiments provide a methodology for designing a large-scale non-blocking OCS using a multi-stage folded CLOS switch architecture for use in datacenter networks and fiber-rich backbone network POPs. One aspect employs a folded CLOS architecture because of its ease of implementation, enabling the topology to scale arbitrarily with increasing number of stages. The fraction of ports allocated for internal switch wiring (overhead) also increases with the number of stages. Design decisions are made to carefully optimize the insertion loss per module, number of ports per module, number of stages and the total scale required. Other embodiments include folded CLOS switch architectures having at least two stages. In one example, power monitoring may be included only on the leaf switches.

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

Abstract: Techniques are provided for using light path priority of service information in an optical network. At a node in the optical network, priority of service information is stored for a plurality of light paths used in the optical network. The node serves traffic in the optical network using the plurality of light paths based on the priority of service information. These techniques provide for prioritizing light paths (wavelengths) for scenarios such as restoration, congestion and resource contention.

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: A method of restoration for an optical network, the network comprising a plurality of nodes (40, 50) interconnected with each other by optical links (130), a subset of the nodes (40) each comprising a regenerator, the method comprising: storing 160) a quality of transmission parameter and a regenerator availability at each of the plurality of nodes (40, 50); notifying (170) a branch node (110) in response to detecting a failure (140) within a link (130) forming part of the path between a source node (20) and a destination node (30), wherein the branch node (110) is the neighbouring upstream node (40, 50) upstream of the link failure (140), the branch node (110) having a regenerator; the branch node (110) computing (190) a restoration segment (100) to a merge node (120) having a regenerator which is a neighbouring downstream node which is downstream of the link failure (140), the restoration path (100) being based on the quality of transmission parameter and regenerator availability information; restoring (180

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: Systems and methods for optical path protection for distributed antenna systems are provided. In one embodiment, a system comprises a hub and at least one node located remotely from the hub. The hub is coupled to the node by first and second fiber paths, the first fiber path comprising an uplink fiber and a downlink fiber, the second fiber path comprising an uplink fiber and a downlink fiber. The node is coupled to the downlink fibers of the first and second fiber paths via an optical combiner, and is further coupled to the uplink fibers of the first and second fiber paths via an optical splitter. The node further monitors a signal quality of a downlink optical signal and communicates to the hub information indicative of the signal quality. The hub switches communications between the hub and the node from the first to second fiber path based on the information.

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: A passive optical network (PON) component comprising a power switch, a detector configured to monitor the power switch, and a processor configured to receive an interrupt from the detector and transmit a message comprising a first indicator that the PON component has powered down, and a second indicator giving a reason for the power down. A passive optical network (PON) component comprising a processor configured to implement a method comprising receiving an interrupt message from a detector, determining a reason for the interrupt, and transmitting a dying gasp message comprising an indicator of the reason for the interrupt. A method comprising transmitting an alarm message comprising an optical network terminal (ONT) manual power off indicator that indicates the ONT is shutting down because a subscriber has turned off its power switch.

Abstract: A network element of an optical communications network. The network element comprises an electronic router for forwarding traffic between a set of client access ports and a plurality of I/O ports. A respective EO interface is coupled to each one of the plurality of I/O ports. Each EO interface terminates a respective optical channel. A directionally independent access (DIA) node is configured to selectively route each optical channel between its respective EO interface and a selected one of at least two optical fiber links of the optical communications network.

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: A relay station has an optical switch that switches a reception path of an optical signal. The relay station generates a subsignal that has a wavelength different from the wavelength of a data signal corresponding to a signal to be transmitted and transmits an optical signal obtained by multiplexing the generated subsignal and the data signal. In this state, when the data signal is not included in the received optical signal, the relay station determines whether the subsignal is included in the optical signal. When it is determined that the subsignal is included, the relay station maintains a connection path of the optical switch without switching the connection path.

Abstract: The technique for improving the efficiency in use of power resources while maintaining the received signal quality that satisfies the requirement during a system operation is disclosed. The frame processing apparatus disclosed in the present case includes: a frame processing unit which performs frame processing on an input signal in the designated error processing mode; and a controlling unit which receives the monitoring result relating to the signal quality of the input signal and performs switching control of the designation of the above error processing mode in the frame processing unit based on the received monitoring result.

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 switch include a switch unit including a light reflection unit of which the reflection direction is changeable, the switch unit configured to optically connect an input port to an output port via the light reflection unit by changing the reflection direction of the light reflection unit; a determining light input unit configured to input into a first predetermined port a determining light for determining malfunctions in the light reflection unit; a light detection unit configured to detect the determining light from the output from a second predetermined port; and a malfunction determining unit configured to determine that abnormalities have occurred when the determining light is detected by the light detection unit.

Abstract: A method and system for protecting against communication loss or disruption in an optical network system includes a signal state detector, which can measure received optical signals and determine if their strength is sufficient to support reliable communications. If the signal state detector informs the control circuit that the received optical signal is too low to support communications with the data service hub (or if there is no signal at all, such as in a severance of an optical waveguide), then the control circuit can instruct the data switch to re-route communications from the primary communication path to a secondary or back up communication path. This switching or re-routing of communications from a primary communication path which is non-functional or inoperative to an operational and fully functional communication path (a back up or secondary communication path) can be completed in a very short time, such as within fifty milliseconds or less.

Abstract: As described herein, a network device includes an optical circuit switch to perform circuit switching. The network device also has a plurality of removable line cards, each of which includes a packet switch. A switching manager automatically reconfigures the optical circuit switch based on a configuration of the removable line cards to maintain a guaranteed packet switching bandwidth between active line cards.

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: Systems and methods are described that that dynamically configure high-speed data link lightpaths between access routers and backbone routers at geographically dispersed locations to reassign traffic when a backbone router fails or is removed from service. Embodiments reduce the quantity of backbone router ports used in dual backbone router-homed networks.

Abstract: An apparatus for simulating radio frequency (RF) signal propagation characteristics in a wireless communication network is disclosed. The apparatus includes a first RF terminal and a second RF terminal. A first optical modulator is in electrical communication with the first RF terminal. An optical delay line is in optical communication with the first optical modulator. A first optical demodulator is in optical communication with the optical delay line and in electrical communication with the first RF terminal. A second optical demodulator is in optical communication with the optical delay line and in electrical communication with the second RF terminal. A second optical modulator is in electrical communication with the second RF terminal and in optical communication with the optical delay line.

Abstract: A method for determining network topology of a provider network includes selecting a first network element, selecting a first port on the first network element, and iteratively performing connectivity validation tests using the first port, wherein each connectivity validation test is associated with a type of network element and yields a result that indicates whether a second port on a second network element of the associated type is connected to the first port. A system for discovering topology of a network, the system comprising a topology discovery engine in operable communication with a near network element and operable to identify a first port of a far network element that is connected to a second port of the near network element by remotely altering operation of the near network element to cause the second network element to respond in a manner that identifies the first port.

Abstract: The disclosure relates to a method and apparatus for implementing self-adaption of cross granularity in an Optical Transport Network (OTN). The method includes: acquiring an optical interface side OTN service signal which has been processed by a frame-forming chip, and performing determination on the frame header of an Optical channel Data Unit (ODU) frame of the current level in the OTN service signal; when frame-alignment is determined to be successful, performing level-by-level de-multiplexing processing on the ODU frame of the current level to obtain cross granularities of different levels, selecting output channels for the cross granularities of different levels, performing mapping processing on the output cross granularities of different levels to form fixed rate service signals, and outputting the fixed rate service signals to back board ports, where the signals are transmitted to a cross board.

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.