Abstract: Adaptive modulation coding schemes improve spectral efficiency of telecommunication networks by implementing MCSs specific to each of a plurality of end devices in operable communication with a hub. For example, the MCSs may be specific to a channel, a wavelength, a distance, or capabilities of an end device. The MCSs are selected to include the highest modulation format and highest forward error correction coding rate that can be applied to a telecommunication signal without surpassing a signal parameter threshold.

Abstract: An optical full-field transmitter (OFFT) includes a plurality of optical circulators and a polarization beam combiner. The plurality of optical circulators are fabricated on a silicon-on-insulator (SOI) substrate, where each of the optical circulators has (a) a first port that optically couples to a high-quality optical source, (b) a second port that optically couples to a child laser configured to receive amplitude modulation data, and (c) a third port optically coupled to a phase modulator that (i) is configured to receive a phase modulation data and (ii) includes an output port that outputs amplitude and phase modulated light. The polarization beam combiner receives the amplitude and phase modulated light from each of the optical circulators and outputs combined amplitude and phase modulated light.

Abstract: A method for tuning a power characteristic of an optical frequency comb includes controlling a modulating light source according to a plurality of modulation parameters to generate an optical frequency comb including a plurality of optical tones. Additionally, at least one of the plurality of modulation parameters is changed until a total power of the plurality of optical tones is greater than or equal to a minimum threshold value. Furthermore, at least one of the plurality of modulation parameters are changed until respective powers of each of the plurality of optical tones are within a predetermined proximity to respective target powers of each of the plurality of optical tones.

Abstract: A beam steering subsystem is provided in an optical communication system. The beam steering subsystem is configured for steering a free-space optical (FSO) beam from a first transceiver to a second transceiver disposed remotely from the first receiver. The beam steering subsystem includes a beam steering device disposed between the first transceiver and the second transceiver, and an optical tracking unit in optical communication and electrical communication with the beam steering device. The wherein the beam steering device is further configured to (i) receive the FSO beam from the first transceiver, (ii) receive an optical tracking signal from the second transceiver, (iii) optically relay the received optical tracking signal to the optical tracking unit, and (iv) steer the FSO beam to the second transceiver based on an electrical feedback control signal from optical tracking unit.

Abstract: Multi-access gateways with intelligent convergence (MAGIC gateways) for use on client premises intelligently distribute user equipment network traffic to/from a plurality of Internet service providers (ISPs), without any change on the ISP network side. Use of a MAGIC gateway improves network reliability by providing redundancy and distributing traffic to those ISPs that provide the best service parameters for the type of traffic being transmitted.

Abstract: A fiber-optic network that uses as a hybrid telecommunication and sensing system when telecommunication signals and probe signals are transmitted across a shared fiber strand in either a co-propagated or counter-propagated direction is disclosed. Probe signals generated by a sensing termination system and/or by one or more end devices are used to analyze conditions affecting network hardware and/or events occurring within the fiber distribution area.

Abstract: A method for allocating bandwidth to a first ONU, a second ONU, M1 ONUs, and M2 ONUs includes, during an allocation cycle, (i) granting a respective upstream time slot to, of a plurality of N ONUs, only each of the M1 ONUs, and (ii) granting a first upstream time slot to the first ONU. Each of the M1 ONUs and M2 ONUs is one of the plurality of N ONUs. The method also includes, during a subsequent cycle, (i) granting a respective upstream time slot to, of the plurality of N ONUs, only each of the M2 ONUs. The N ONUs includes a skipped-ONU that is one of either, and not both, the M1 ONUs and the M2 ONUs. The method includes, during the subsequent allocation cycle, granting a second upstream time slot to a second ONU, which is not one of the plurality of N ONUs.

Abstract: Described embodiments include a circuit for adapting the on time in a switching voltage converter that includes a first transistor having a current terminal coupled to an output voltage terminal and to its control terminal. A second transistor is coupled between the first transistor and a ground terminal, and has a control terminal coupled to the first transistor. A third transistor is coupled between the output voltage terminal and a capacitor, and has a third control terminal coupled to the first control terminal. A current source is configured to provide a current that varies linearly between a first value and a second value. A fourth transistor is coupled between terminals of the capacitor, and has a fourth control terminal. A comparator has a first comparator input coupled to the capacitor. A logic circuit has an input coupled to the comparator output, and an output coupled to the fourth control terminal.

Abstract: Adaptive modulation coding schemes improve spectral efficiency of telecommunication networks by implementing MCSs specific to each of a plurality of end devices in operable communication with a hub. For example, the MCSs may be specific to a channel, a wavelength, a distance, or capabilities of an end device. The MCSs are selected to include the highest modulation format and highest forward error correction coding rate that can be applied to a telecommunication signal without surpassing a signal parameter threshold.

Abstract: An optical full-field transmitter for an optical communications network includes a primary laser source configured to provide a narrow spectral linewidth for a primary laser signal, and a first intensity modulator in communication with a first amplitude data source. The first intensity modulator is configured to output a first amplitude-modulated optical signal from the laser signal. The transmitter further includes a first phase modulator in communication with a first phase data source and the first amplitude-modulated optical signal. The first phase modulator is configured to output a first two-stage full-field optical signal. The primary laser source has a structure based on a III-V compound semiconductor.

Abstract: A coherent passive optical network includes a downstream transceiver and first and second upstream transceivers in communication with an optical transport medium. The downstream transceiver includes a downstream processor for mapping a downstream data stream to a plurality of sub-bands, and a downstream transmitter for transmitting a downstream optical signal modulated with the plurality of sub-bands. The first upstream transceiver includes a first local oscillator (LO) for tuning a first LO center frequency to a first sub-band of the plurality of sub-bands, and a first downstream receiver for coherently detecting the downstream optical signal within the first sub-band. The second upstream transceiver includes a second downstream receiver configured for coherently detecting the downstream optical signal within a second sub-band of the plurality of sub-bands. The downstream processor dynamically allocates the first and second sub-bands to the first and second transceivers in the time and frequency domains.

Abstract: A method for chromatic dispersion pre-compensation in an optical communication network includes (1) distorting an original modulated signal according to an inverse of a transmission function of the optical communication network, to generate a compensated signal, (2) modulating a magnitude of an optical signal in response to a magnitude of the compensated signal, and (3) modulating a phase of the optical signal, after modulating the magnitude of the optical signal, in response to a phase of the compensated signal.

Abstract: A method for allocating bandwidth to a first ONU, a second ONU, M1 ONUs, and M2 ONUs includes, during an allocation cycle, (i) granting a respective upstream time slot to, of a plurality of N ONUs, only each of the M1 ONUs, and (ii) granting a first upstream time slot to the first ONU. Each of the M1 ONUs and M2 ONUs is one of the plurality of N ONUs. The method also includes, during a subsequent cycle, (i) granting a respective upstream time slot to, of the plurality of N ONUs, only each of the M2 ONUs. The N ONUs includes a skipped-ONU that is one of either, and not both, the M1 ONUs and the M2 ONUs. The method includes, during the subsequent allocation cycle, granting a second upstream time slot to a second ONU, which is not one of the plurality of N ONUs.

Abstract: A fiber-optic network is used to interrogate a geographic area for propagating waves initiated by events external to the fiber-optic network. The probe signals are frequency modulation aligned and/or carrier frequency aligned with one another. Scattered energy indicative of probe signals' interactions with the propagating wave are time aligned with one another, amplitude normalized, cross correlated and/or added together to improve signal-to-noise and spatial resolution.

Abstract: An injection locking laser source is provided for an optical communications system. The injection locking laser source includes a laser cavity configured to receive an externally injected low linewidth primary light source. The laser cavity includes a cavity length, a cavity facet reflectivity, and a cavity quality factor. The injection locking laser source further includes an emitting region configured to output a secondary light source injection locked to the externally injected low linewidth primary light source at a stable detuning frequency based on a photon number, a steady-state phase, and a carrier number of the primary light source injected into the cavity.

Abstract: A communications network includes a central communication unit, an optical transport medium, and a plurality of remote radio base stations. The central communication unit generates, within a selected millimeter-wave frequency band, a plurality of adjacent two-tone optical frequency conjugate pairs. Each conjugate pair includes a first optical tone carrying a modulated data signal, and a second optical tone carrying a reference local oscillator signal. The optical transport medium transports the plurality of two-tone conjugate pairs to the plurality of radio base stations, and each base station receives at least one conjugate pair at an optical front end thereof. The optical front end separates the first optical tone from the second optical tone, and converts the first optical tone into a millimeter-wave radio frequency electrical signal.

Abstract: An injection locked transmitter for an optical communication network includes a master seed laser source input substantially confined to a single longitudinal mode, an input data stream, and a laser injected modulator including at least one slave laser having a resonator frequency that is injection locked to a frequency of the single longitudinal mode of the master seed laser source. The laser injected modulator is configured to receive the master seed laser source input and the input data stream, and output a laser modulated data stream.

Abstract: An echo cancellation method includes steps of (a) extracting phase-distortion estimates, (b) reconstructing an echo signal, (c) generating a clean signal, and (d) producing a primary signal. Step (a) includes extracting, from a first phase signal, a plurality of phase-distortion estimates, the first phase signal having been estimated from an echo-corrupted signal received at a first coherent transceiver of a coherent optical network. Step (b) includes reconstructing an echo signal from the plurality of phase-distortion estimates and a transmitted signal transmitted by the first coherent transceiver. Step (c) includes generating a clean signal as a difference between the reconstructed echo signal and the first phase signal. Step (d) includes producing a primary signal by mapping each of a plurality of clean-phase estimates of the clean signal to one of a plurality of constellation symbols associated with a modulation scheme of the primary signal.

Abstract: A method for estimating a chromatic dispersion of an optical-fiber channel is disclosed includes receiving, via the optical-fiber channel, a chromatically-dispersed signal having a symbol rate 1/T. The method also includes, for each chromatic-dispersion value of a plurality of chromatic-dispersion values, determining a respective clock-tone magnitude by: (i) applying, to the chromatically-dispersed signal or a signal derived therefrom, a chromatic dispersion equal to the chromatic-dispersion value to generate a dispersion-compensated signal, and (ii) extracting the clock-tone magnitude from at least one of a positive-frequency clock-tone and a negative-frequency clock-tone of the dispersion-compensated signal, the positive-frequency clock-tone and the negative-frequency clock-tone being spectral components of the dispersion-compensated signal at temporal frequencies 1/T or ?1/T respectively. The method also includes determining a maximum of the extracted clock-tone magnitudes.

Abstract: A method for traffic flow classification in a communication network includes (1) identifying a traffic flow in communication network traffic, (2) extracting features of the traffic flow, and (3) using a machine learning model, classifying the traffic flow at least partially based on the features of the traffic flow. The features of the traffic flow include, for example, a distribution of packet size values of a sliding window sample of the traffic flow, a distribution of inter-arrival time values of a sliding window sample of the traffic flow, standard deviation of data packet size, average of data packet size, standard deviation of data packet inter-arrival time, and average of data packet inter-arrival time.