Automatic laser shutdown and recovery in response to a link break
Granted: February 16, 2016
Patent Number:
9264134
A communication system may include a first control circuit to detect a break on a first optical link; a first optical source to supply a first optical signal on a second optical link in response to detecting the break on the first optical link, the first optical signal propagating in a first direction on the second optical link; a second control circuit to detect a presence of the first optical signal on the second optical link, and output a control signal in response to detecting the…
Rotator external to photonic integrated circuit
Granted: February 16, 2016
Patent Number:
9261635
An optical system may include a polarization beam splitter having an input that receives multiple optical signals, a first output and a second output. The first output may provide components of the multiple optical signals having a first polarization. The second output may provide components of the multiple optical signals having a second polarization. The optical system may include a rotator having an input that receives the components to rotate the first polarization such that each of…
Optical layer protection switching applications
Granted: February 9, 2016
Patent Number:
9258215
Systems and methods are disclosed for modulating, with circuitry of a source node in a communication network, at least one optical carrier to carry data utilizing a format of a soft decision forward error correction (SD-FEC) data field of an overhead portion of a data frame; encoding, with the circuitry of the source node, first data being SD-FEC data and second data being additional data into the SD-FEC data field, the first and second data being accessible without accessing client data…
Polarization beam splitter
Granted: February 9, 2016
Patent Number:
9256084
An optical system may include: a polarization beam splitter having: a first end having an input configured to receive multiple optical signals; a second end having a first output and a second output, where the first output may provide first components, having a first polarization of the multiple optical signals, and the second output may provide second components, having a second polarization, of the multiple optical signals; and a first waveguide having a first width and a second…
OAM in OTN networks: GMPLS signaling for TCM
Granted: February 2, 2016
Patent Number:
9253067
Methods and nodes are disclosed for OAM configuring one or more tandem connection monitoring layers through GMPLS signaling during GMPLS sub-network connection (SNC) establishment. Additionally, methods and nodes are disclosed for OAM configuring one or more tandem connection monitoring layers through GMPLS signaling after GMPLS sub-network connection establishment, that is, for existing connections.
Disjoint path computation for arbitrary directed graph
Granted: February 2, 2016
Patent Number:
9253032
Systems and methods for accessing network configuration data identifying one or more working path(s) configured to transport data between source and destination nodes, wherein multiple working paths are prioritized, and including at least one first diversity weight of a first value indicative of at least one communication link in the working path(s), and at least one second diversity weight of a second value indicative of at least one communication link outside of the working path(s);…
Equalizing a signal modulated using a 5QAM modulation format
Granted: January 26, 2016
Patent Number:
9246735
An optical system may include an optical transmitter or an optical receiver. The optical transmitter may include a laser to provide an input signal, a first digital signal processor (DSP) to receive a data signal, provide non-rotated and rotated symbols corresponding to the data signal, and provide digital signals corresponding to the non-rotated and the rotated symbols to cause one or more digital to analog converts to convert the digital signals to analog signals. The optical…
Network planning and optimization of equipment deployment
Granted: January 26, 2016
Patent Number:
9246704
Embodiments of the present invention provide systems, devices and methods for improving the efficient deployment and configuration of networking equipment within a network build-out. In certain embodiments of the invention, an iterative analysis of inter-node equipment placement and connectivity, and inter- and intra-node traffic flow is performed to identify a preferred deployment solution. This analysis of deployment optimization takes into account both configurations from a network…
Dual rate QPSK/TCM-QPSK optical modulation
Granted: January 26, 2016
Patent Number:
9246597
The present disclosure allows for optical link capacity to be optimized based on transmission parameters, such as amplifier gain, link loss, optical signal-to-noise ratio. For example, optical signals at wavelengths that are susceptible to impairments, such as non-linear effects, or that are not adequately amplified by an optical amplifier, may be modulated in accordance with lower rate/less spectrally efficient modulation formats (“low rate formats”) that are more noise tolerant. On…
Super optical channel data unit signal supported by multiple wavelengths
Granted: January 12, 2016
Patent Number:
9236969
A node is configured to receive first optical channel data unit (ODU) signals; encapsulate the first ODU signals into a second ODU signal; distribute data of the second ODU signal to a group of third ODU signals; encapsulate each of the third ODU signals into a respective optical channel transport unit (OTU) signal; and transmit each of the OTU signals on a respective optical channel of a group of optical channels. Each optical channel, of the group of optical channels, has a…
Detecting and correcting cycle slips to minimize system penalty
Granted: January 12, 2016
Patent Number:
9236952
An optical receiver receives an optical signal with a phase error and pilot symbols, and converts the optical signal into an electrical signal. The optical receiver identifies, based on the pilot symbols, a cycle slip due to the phase error and associated with a transition time. The optical receiver determines, based on the pilot symbols, a direction and a center of the cycle slip, and generates a rotation value based on the direction and the center. The optical receiver applies the…
Channel skew identification and notification
Granted: January 5, 2016
Patent Number:
9231798
Embodiments of the present invention analyze a plurality of parallel channels and identify specific channel(s) that have skew outside of an acceptable skew error margin. In certain embodiments, this skew is identified by determining the timing misalignment between a channel under test and a deskew channel. Other channels within the plurality of channels are masked by transmitting a repeating masked bit pattern. This timing misalignment may be measured by comparing a segment within the…
Methods and apparatus for minimizing wander generation in constant bit rate asynchronously mapped digital transport systems
Granted: December 29, 2015
Patent Number:
9225446
A client receive circuit receives client data from a network, decodes the client data and stores the client data within the memory. A frame transmit circuit is provided that includes a justification control logic and a framer and a justification control logic is provided that 1) determines each of a plurality of fill levels and 2) determines an average of the plurality of fill levels. The framer has circuitry to generate a wrapper including a justification opportunity having data based…
Forward carrier recovery using forward error correction (FEC) feedback
Granted: December 22, 2015
Patent Number:
9219550
A system receive, from an optical receiver, a signal derived from a first optical signal and a second optical signal generated by a local oscillator, that includes a first component that is an in-phase component and a second component that is a quadrature phase component; filter the signal, using a filter, set to one or more configurations, to obtain one or more recovered signals, where each of the recovered signals includes a respective quantity of noise; perform forward error…
Quality of service application for different data flow types
Granted: November 17, 2015
Patent Number:
9191114
A network device is configured to store parameters identifying a respective quality of service (QoS) to apply to corresponding different types of data flows; initiate establishment of a network channel between a source device and a destination device through an optical network; receive first and second data flows destined for the destination device, where the first data flow and the second data flow may have first and second data flow types; identify a first QoS and a different second…
Suppression of non-linear effects in low dispersion optical fibers
Granted: November 3, 2015
Patent Number:
9178641
Consistent with the present disclosure, chromatic dispersion is introduced into an optical communication path including multiple segments or spans of dispersion shifted fiber (DSF). The chromatic dispersion generates phase mismatching between optical signals propagating along the optical communication path, i.e., the optical signals are decorrelated, such that mixing products are reduced inmagnitude, and the noise attributable to four wave mixing is correspondingly reduced.
Accurate calculation of polarization mode dispersion using blind equalization
Granted: November 3, 2015
Patent Number:
9178624
A digital signal processor (DSP) may receive a signal that has an x-polarization (x-pol) and a y-polarization (y-pol). The DSP may equalize the x-pol of the signal and the y-pol of the signal based on filter coefficients determined using a constant modulus algorithm (CMA). The DSP may perform phase correction on the equalized x-pol signal and the equalized y-pol signal. The DSP may identify a first frame header pattern within the phase-corrected x-pol signal, and may identify a second…
Suppression of resonant polarization conversion in photonic integrated circuits
Granted: October 27, 2015
Patent Number:
9170438
A device may include a number of optical waveguides, each of which being spaced from one another. The optical waveguides may each include at least one curved section and widths of the curved sections of the optical waveguides may be selected to reduce polarization conversion of light traversing the birefringent optical waveguides.
Discovery of an adjacent network element within a network data plane
Granted: October 27, 2015
Patent Number:
9172489
The present invention provides a system, apparatus and method for discovery of network elements, which are adjacent within the network data plane but may or may not be adjacent in the network control plane. In one embodiment of the present invention, digital network elements, with a plurality thereof having a lambda switching capability (hereinafter “LSC”) interface, is provided. A digital network element with an LSC interface originates and sends a local advertisement to its…
Raman pump circuit
Granted: October 27, 2015
Patent Number:
9172467
A Raman pump may include a dual output laser configured to output two optical signals; a delay interferometer configured to delay a first of the two optical signals to decorrelate the two optical signals from each other; and a combiner configured to combine the delayed first of the two optical signals and a second of the two optical signals to provide a Raman amplification signal.
