Abstract: Techniques are described for implementing an out-of-band communication channel used to exchange control channel information in sub-carrier-based optical communication systems. In an example implementation, a transmitter includes a laser operable to supply an optical signal, a digital signal processor operable to supply first electrical signals based on first data input to the digital signal processor and second data input to the digital signal processor, digital-to-analog conversion circuitry operable to output second electrical signals based on the first electrical signals, modulator driver circuitry is operable to output third electrical signals based on the second electrical signals, and an optical modulator operable to supply first and second modulated optical signals based on the third electrical signals. The first modulated optical signal includes a plurality of optical subcarriers carrying user data. The second modulated optical signal is polarization modulated based on the second data.

Abstract: A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to receive data carrying optical signals from, and supply data carrying optical signals to, the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, optical splitters/combiners, and optical add/drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced.

Abstract: A telecommunication appliance and method is described. In the method, a flexible cover part of an appliance cover of a telecommunication appliance supported by a telecommunication rack is removed while the telecommunication appliance is in service and passing data. The telecommunication appliance has a plurality of pluggable optical modules installed within connectors within a space encompassed by the appliance cover. The connectors are operably connected to a power supply supplying power to the connectors. When a first one of the connectors is devoid of a pluggable optical module being installed within the first one of the connectors, a first pluggable optical module is plugged into the first one of the connectors.

Abstract: Consistent with the present disclosure, codewords indicative of a super Gaussian distribution may be encoded and decoded using the encoders and decoders disclosed herein. Based on such codewords, symbols may be transmitted in accordance or in conformance with a super Gaussian distribution to tailor the SE of an optical signal or subcarrier for a given link having non-linear degradations and shaping gain. Such tailed SE may not be achievable with a Gaussian symbol transmission probability distribution.

Abstract: A method and system are herein disclosed. A coherent optical receiver receives a first optical data carrier signal at a first instant of time and a second optical data carrier signal at a second instant of time, generates at least four first data streams from the first optical data carrier signal and at least four second data streams from the second optical data carrier signal; and circuitry calculates a first aggregate power of the first data streams and a second aggregate power of the second data streams; applies an adjustable temporal low pass filter to the first aggregate power and the second aggregate power resulting in a compensation power, the adjustable temporal low pass filter adjusted to achieve a performance metric; and phase-rotates the first data streams and the second data streams proportional to the compensation power.

Abstract: Optical network systems and components are disclosed, including a transmitter comprising a digital signal processor receiving a plurality of independent data streams, and supplying a plurality of digital subcarrier outputs, based on the plurality of independent data streams, and configurable to vary the frequency spacing between two or more of the plurality of digital subcarrier outputs; the transmitter configured to output a modulated optical signal including a plurality of optical subcarriers based on the digital subcarrier outputs wherein based on first ones of the plurality of digital outputs, the first one of the plurality of subcarriers is spectrally spaced from the second one of the plurality subcarriers by a first gap, and based on second ones of the plurality of digital outputs, the first one of the plurality of subcarriers is spectrally spaced from the second one of the plurality of subcarriers by a second gap different than the first.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for transmitting signals with a high data rate. In some implementations, an apparatus includes a first digital signal processor outputting first data at a first data rate. A second digital signal processor outputting second data at a second data rate. A filter circuitry receiving and up-sampling the first and second data. Additionally, the apparatus includes a combiner circuit that receives the first up-sampled data and the second up-sampled data, the combiner circuit combining the first and second up-sampled data to provide a multiplexed output, the multiplexed output having a third data rate that is greater than the first data rate or the second data rate.

Abstract: This disclosure describes digitally generating sub-carriers (SCs) to provide isolation and dynamic allocation of bandwidth between uplink and downlink traffic between transceivers that are communicatively coupled via a bidirectional link including one or more segments of optical fiber. Separate uplink and downlink communication channels may be created using digitally generated SCs and using the same transmitter laser. In some implementations, one or more of the nodes include a transceiver having at least one laser and one digital signal processing (DSP) operable for digitally generating at least two SCs and detecting at least two SCs. The transceiver can transmit selected SCs, and can receive other SCs. Accordingly, the transceiver can facilitate bidirectional communication, for example, over a single optical fiber link. In some instances, techniques can facilitate dynamic bandwidth assignment by facilitating adding or blocking of optical subcarriers from transmission in an uplink or downlink direction.

Abstract: Methods, systems, transceivers, and apparatus are included for clock synchronizing an optical system and multiple leaf systems. In some implementations, a transceiver includes a receiver and a transmitter. The receiver includes an optical hybrid circuit operable to receive a first modulated optical signal and local oscillator light and to supply optical mixing products based on the first modulated optical signal and the local oscillator light. A photodiode circuit operable to supply an electrical signal based on the optical mixing products. An analog-to-digital conversion circuitry operable to supply digital signals based on the electrical signal. A digital signal processor operable to generate a supply signal based on the digital signals and provide the supply signal to a reference clock circuit for generating a clock signal. The transmitter is operable to output a second modulated optical signal that includes a timing of data based on the clock signal.

Abstract: A telemetry manager receives, from a network server, global data collection information about network components in an optical network device. The global data collection information includes identifiers for network nodes in the network components from which telemetry data are to be collected, and reporting frequency and encoding format for sending collected telemetry data to the network server. The telemetry manager identifies, from the global data collection information, local data collection information specified for a network component, and sends this information to a telemetry agent in the network component. The telemetry manager receives telemetry data generated by a network node of the network component, where the data is provided according to instructions in the local data collection information. The telemetry manager converts the telemetry data from its native format to an encoding format specified by the global data collection information, and sends the encoded telemetry data to the network server.

Abstract: A method of fabricating a heat pipe may include providing a first material as a body section. The method may include stamping or etching the body section to include the cavity. A portion of the body section may constitute a wall of the cavity. The method may include stamping or etching the wall of the cavity to provide a set of corrugations on a portion of the wall of the cavity. The method may include forming an opening in the wall of the cavity. The method may include attaching a lid over the cavity. The lid constituting at least a portion of a hermetic seal of the cavity. The method may include attaching a cover to the body section approximately adjacent to the opening in the cavity. The method may include attaching a valve to the body section approximately at the opening to the cavity.

Abstract: Techniques are described for implementing an out-of-band communication channel used to exchange control channel information in sub-carrier-based optical communication systems. In an example implementation, an apparatus includes an optical tap coupled to an optical communication path carrying a modulated optical signal carrying a plurality of optical subcarriers. The optical tap has a first output configured to supply a first portion of the modulated optical signal and a second output configured to supply a second portion of the modulated optical signal. The plurality of optical subcarriers are amplitude modulated based on control data at a first frequency, and each of the plurality of optical subcarriers is modulated to carry user data at a second frequency greater than the first frequency. The apparatus is configured to supply the control based on the first portion of the modulated optical signal.

Abstract: An optimized communication network may include an edge switch capable of transporting and switching L1 and L2 traffic and configured to selectively transport and switch L2 traffic using L1 protocols.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for clock recovery in subcarrier based coherent optical systems. In one aspect, an apparatus includes a plurality of phase detectors configured to generate a plurality of phase detection outputs by detecting a plurality of digital signals associated with a plurality of frequency bands, each of the plurality of phase detection outputs being associated with a respective one of the plurality of frequency bands, alignment circuitry coupled to the plurality of phase detectors and configured to align phases of the plurality of phase detection outputs to be substantially same, and averaging circuitry coupled to the alignment circuitry and configured to generate a particular output based on the plurality of phase detection outputs with the aligned phases. The plurality of digital signals is adjusted based on the particular output.

Abstract: A device may be configured to receive a text file including network information for an optical network. The network information may include information for an optical route in the optical network. The device may generate a user interface based on the text file. The user interface may display a representation of the optical route. The device may provide the user interface for display and receive a user input via the user interface. The device may change the representation of the optical route displayed by the user interface based on the user input and the network information included in the text file.

Abstract: Methods, devices, and systems for mapping transport segment labels to packet network endpoints using a mapping server. In some implementations, an end point address in an edge domain is received from an edge router, a mapping of one of the end point address to a transport segment label is received from a network device, the mapping is stored in a non-transitory memory device, and the mapping is transmitted to the edge router.

Abstract: Systems and methods are described in which circuitry of a first controller of a first node receives a first signal indicating an optical loss of signal within the first path. Circuitry of a second controller of the first node on the first path within a transport network generates a second signal indicating a failure within the first path. The first controller accessing a network topology database determines that restoration of the first path would be ineffective due to there being no alternate path, and signals a second node downstream in the first path with the second signal indicating the failure within the first path, and a third signal indicating that restoration of the first path would be ineffective due to there being no alternate path.

Abstract: Methods, nodes and control modules are disclosed. In the method, circuitry of a first node in a mesh network converts an optical layer in a working path between the first node and a second node, to a data stream in a digital layer. The working path carries data traffic from the first node to the second node in the optical layer of the mesh network when there is no failure in the working path. Circuitry of the first node in the mesh network detects a failure in the working path due to detection of an error in the data stream in the digital layer. The circuitry of the first node establishes, through transmission of at least one signal from the first node to the second node, a restoration path in the optical layer based on, at least in part, detection of the error in the data stream in the digital layer.

Abstract: Consistent with an aspect of the present disclosure, electrical signals or digital subcarriers are generated in a DSP based on independent input data streams. Drive signals are generated based on the digital subcarriers, and such drive signals are applied to an optical modulator, including, for example, a Mach-Zehnder modulator. The optical modulator modulates light output from a laser based on the drive signals to supply optical subcarriers corresponding to the digital subcarriers. These optical subcarriers may be received by optical receivers provided at different locations in an optical communications network, where the optical subcarrier may be processed, and the input data stream associated with such optical subcarrier is output. Accordingly, instead of providing multiple lasers and modulators, for example, data is carried by individual subcarriers output from an optical source including one laser and modulator. Thus, a cost associated with the network may be reduced.

Abstract: An optical device having an amplifier and a controller is described. The amplifier is configured to amplify an optical signal in at least one of the C-Band or the L-Band. The controller includes a processor and a non-transitory computer readable medium. The non-transitory computer readable medium storing computer executable code that when executed by the processor causes the processor to: select a target tilt and gain setting from a plurality of target tilt and gain settings stored in the non-transitory computer readable medium based on the type of fault event message responsive to a fault event message affecting the C-band or the L-Band. The selected and pre-calculated target tilt and gain settings are applied to the amplifier.