Patent application number | Description | Published |
20090046574 | Virtual Circuit Connectivity Verification Insertion for Packet Loss Control in Pseudowire - A method includes inserting a virtual circuit connectivity verification packet into aggregated traffic of m packets transmitted over multiple pseudowires in a network path, replying to the transmitted m packets with a virtual circuit connectivity verification packet with a packet loss indication when at least one packet loss is detected in an m packet group, and adjusting a rate of transmitting the aggregated m packets responsive to the packet loss indication. In the preferred embodiment the multiple pseudowires are one of constant bit rate and variable bit rate and the adjusting of the rate includes rate adjustment of variable bit rate pseudowires. | 02-19-2009 |
20090080551 | Bandwidth Efficient Coding for an Orthogonal Frequency Multiplexing OFDM System - A method for encoding an OFDM signal includes pairing two adjacent subcarriers of an OFDM signal as a group, changing a modulated symbol set of the OFDM signal to a modified symbol set for coding the OFDM signal, and providing a modified baseband OFDM signal with an increased frequency separation between the subcarriers and reducing the total number of subcarriers being used for transmission over each OFDM symbol interval. | 03-26-2009 |
20090092389 | Orthogonal Frequency Division Multiple Access Based Optical Ring Network - A fiber optic network transmits data between a hub node and a plurality of local nodes connected by at least one unidirectional fiber ring. Downstream data streams are carried on wavelength-division-multiplexed optical carriers from the hub node to the local nodes. An optical carrier corresponding to a specific wavelength carries downstream data streams to a specific local node. Downstream data streams are multiplexed onto an optical carrier via orthogonal frequency division multiplexing. A parallel signal detector in each local node detects all downstream optical carriers. A signal processing module demultiplexes the data stream from the optical carrier having the specific wavelength corresponding to the local node. An upstream data stream is multiplexed via orthogonal frequency division multiplexing onto an upstream optical carrier having the same specific wavelength and transmitted from the local node to the hub node. Upstream data awaiting transmission is allocated to specific subcarriers and time slots. | 04-09-2009 |
20090092393 | Coherent Optical Orthogonal Frequency Division Multiplexing (OFDM) Reception Using Self Optical Carrier Extraction - A method includes producing interference between a received optical OFDM signal and an optical carrier extracted from the received optical OFDM signal to provide optical coherent detection of the received optical OFDM signal. Preferably, producing the interference includes optically splitting the received optical OFDM signal into a first part that is filtered to extract the carrier from the received optical OFDM signal and a second part similar to the received optical OFDM signal. | 04-09-2009 |
20090092394 | Orthogonal Frequency Division Multiple Access Based Virtual Passive Optical Network (VPON) - Various types of passive optical networks operate simultaneously in one passive optical network system comprising an optical line terminal, a passive remote node, and multiple optical network units. Downstream data is orthogonal frequency division multiplexed onto a single wavelength optical carrier transmitted on a primary downstream optical beam from the optical line terminal to a splitter in the passive remote node. The primary downstream optical beam is split into multiple secondary downstream optical beams; each is transmitted to a specific optical network unit. Upstream data is orthogonal frequency division multiplexed onto a single wavelength optical carrier transmitted on a secondary upstream optical beam from each optical network unit to a coupler in the passive remote node. The upstream wavelength for each optical network unit is different. The wavelength division multiplexed optical beam is transmitted from the passive remote node to a parallel signal detector in the optical line terminal. | 04-09-2009 |
20090097852 | 10 Gbps OFDMA-PON - A method for generating transparent pipes for heterogeneous service transmission via OFDMA-PON. In an exemplary embodiment, dedicated sub-channels, which are composed of one or more subcarriers—are used as a “transparent pipe” for delivery of arbitrary analog or digital signals for both circuit switched and packet switched systems. | 04-16-2009 |
20090162066 | Intra-Channel Equalizing Optical Interleaver - An apparatus includes an interleaver configuration for at least one of combining or separating odd and even channel groups to achieve channel density doubling; and an optical equalizer for suppressing inter symbol interference within the channels to provide intra-channel equalizing in the optical path, the equalizer being integrated into the interleaver. Preferably, optical equalizer and interleaver are integrated together as a single monolithic device, the optical equalizer includes a passband that has a dip in the channel center to achieve a raised-cosine filtering profile in the optical signal path to achieve inter-symbol interference ISI suppression, and the equalizer includes integration into the optical path of the interleaver to realize a monolithic device combining or separating odd and even channel groups to achieve channel density doubling. Preferably, also, the optical equalizer includes a first equalizer with half the depth of required ripple dips at both a first output port and an input port and a second equalizer with half the depth of required ripple dips at a second output port. | 06-25-2009 |
20090199065 | GLDPC ENCODING WITH REED-MULLER COMPONENT CODES FOR OPTICAL COMMUNICATIONS - A method of encoding for optical transmission of information includes encoding information with a generalized low-density parity-check (GLDPC) code for providing coding gains, and constructing the GLDPC code with a Reed-Muller RM code as a component code, the component code being decodable using a maximum posterior probability (MAP) decoding. In a preferred embodiment, the GLDPC code includes a codeword length of substantially 4096, an information word length of substantially 3201, a lower-bound on minimum distance of substantially greater than or equal to 16, a code rate of substantially 0.78 and the RM component code includes an order of substantially 4 and an r parameter of substantially 6. | 08-06-2009 |
20090214210 | 100 Gbit/s OFDM Optical Signal Generation - A method includes modulating lightwaves to provide first and second OFDM signal sidebands at a first polarization direction and first and second OFDM signal sidebands at a second polarization direction, and combining sidebands that are oppositely positioned and joined from the first and second OFDM signal sidebands at each polarization direction to provide a polarization multiplexing OFDM signal. | 08-27-2009 |
20090226169 | Programmable Optical Network Architecture - A programmable optical network architecture and associated components employing a two-level orthogonal frequency division multiplexing (OFDM)/wavelength division multiplexed (WDM) mechanisms for bandwith virtualization. | 09-10-2009 |
20090257344 | ALL OPTICAL OFDM WITH INTEGRATED COUPLER BASED IFFT/FFT AND PULSE INTERLEAVING - A method and apparatus for all optical orthogonal frequency division multiplexing (OFDM) employing Inverse Fast Fourier Transform/Fast Fourier Transform by integrated coupler interferometrically. | 10-15-2009 |
20090282314 | MULTIDIMENSIONAL TURBO PRODUCT CODES AND GENERALIZED LOW-DENSITY PARITY-CHECK CODES WITH COMPONENT REED-SOLOMON CODES FOR OPTICAL TRANSMISSION - A transmitter, a receiver, and corresponding methods are provided. The transmitter includes encoders configured to encode source bit streams from L information sources into bytes of codewords. Each encoder includes different (n, k) multidimensional turbo-product codes of code rate R=k/n, where k is a number of information bytes, and n is code word length. The encoders operate in at least two phases. A first phase involves operating k | 11-12-2009 |
20090290877 | Monitoring for High Speed OFDM Signal Transmission - A method includes coupling an optical signal upconverted to a higher frequency and a digital signal having a bit rate similar to that of a subchannel of the upconverted optical signal, and obtaining, responsive to the coupling, a transmission signal with an optical carrier frequency carrying the digital signal and subchannels about the optical carrier frequency carrying the upconverted optical signal, the bit rate of the optical carrier being similar to that of the subchannels. In a preferred embodiment, the coupling includes electrically power coupling the upconverted optical signal with the digital signal, and modulating the coupled optical carrier frequency carrying the digital signal and subchannels about the optical carrier frequency carrying the upconverted optical signal. | 11-26-2009 |
20090290878 | Generating an Optical OFDM Signal with Reduced OSNR Requirement - A method for generating an optical OFDM signal with reduced optical signal to nose ratio requirement includes separating an up-converted OFDM signal into a first part and a second part out of phase with the first part; driving a modulator with the first and second parts of the of the up-converted OFDM signal; and varying a lightwave with the modulator for generating a carrier suppressed OFDM signal having improved receiver sensitivity. | 11-26-2009 |
20090297144 | POLARIZATION MODE DISPERSION COMPENSATION IN MULTILEVEL CODED-MODULATION SCHEMES USING BLAST ALGORITHM AND ITERATIVE POLARIZATION CANCELLATION - Receivers and methods are provided for polarization mode dispersion compensation in multi-level coded-modulation schemes using a BLAST algorithm and iterative polarization cancellation. A receiver includes a vertical Bell Laboratories Layered Space-Time Architecture (V-BLAST) orthogonal frequency division multiplexing (OFDM) detector configured to receive input sequences and partially cancel polarization interference with respect to the input sequences to output symbol estimates for the input sequences. The receiver further includes one or more low-density parity-check (LDPC) decoders coupled to the V-BLAST OFDM detector configured to receive channel bit reliabilities and output code words. The channel bit reliabilities are indirectly calculated from the symbol estimates. The one or more LDPC decoders iteratively provide extrinsic soft information feedback to the V-BLAST OFDM detector to compensate for the polarization interference. | 12-03-2009 |
20090310966 | DIRECT DETECTION RECEIVER USING CROSS-POLARIZATION INTERFEROMETER FOR POLMUX-ASK SYSTEM - A differential delay detection system and method includes an optical splitter to split an incoming optical signal between a first path and a second path. The first path includes a cross-polarization interferometer configured to separately generate polarization independent outputs using split paths and to generate cross-polarization interference outputs, balanced photodetectors to aid in removing cross-polarization beating noise, and a polarization demultiplexer configured to combine the polarization independent outputs and the cross-polarization interference outputs from the cross-polarization interferometer with updated coefficients received from the second path to remove the cross-polarization mixed signals. The second path includes a training signal receiver configured to compute the updated coefficients and output the updated coefficients to the polarization demultiplexer. | 12-17-2009 |
20100027994 | Phase Modulation Of An Optical Orthogonal Frequency Division Multiplexing Signal - A method includes generating an optical orthogonal frequency division multiplexing OFDM signal with in-phase and quadrature-phase components; varying an RF carrier according to the in-phase and quadrature-phase components; and modulating a phase of a lightwave carrier according to the varied RF carrier to generate an optical OFDM signal with equalized amplitude. | 02-04-2010 |
20100028001 | Generation Of At Least 100 Gbit/s Optical Transmission - A method includes generating at least two lightwave carriers from a lightwave source, the carriers having a wavelength spacing, creating an up-subchannel and a down-subchannel orthogonal to one another and spaced apart based on the fixed wavelength spacing from modulations of the lightwave carriers according to respective up-converted OFDM signals that are carrier suppressed, and combining one lightwave from the up-subchannel and one lightwave from the down-subchannel into an optical channel for transmission over an optical fiber. | 02-04-2010 |
20100050048 | MITIGATION OF FIBER NONLINEARITIES IN MULTILEVEL CODED-MODULATION SCHEMES - A receiver and method are provided for mitigation of finer non-linearities in multilevel coded-modulation schemes. The receiver includes a multilevel Bahl-Cocke-Jelinek-Raviv (BCJR) equalizer configured to receive channel samples of an input signal, partially mitigate fiber non-linearities, and provide symbol reliabilities. The receiver further includes a bit probabilities module coupled to the BCJR equalizer configured to calculate soft bit reliabilities from the symbol reliabilities. The receiver also includes one or more low-density parity-check (LDPC) decoders coupled to the bit probabilities module and the BCJR equalizer, configured to receive the soft bit reliabilities and output code words. The one or more LDPC decoders iteratively provide extrinsic soft information feedback to the BCJR equalizer to compensate for the fiber non-linearities. | 02-25-2010 |
20100054735 | OPTICAL OFDMA NETWORK WITH DYNAMIC SUB-CARRIER ALLOCATION - A system and method for dynamically allocating sub-carriers between the nodes of an optical OFDMA ring network or an OFDMA passive optical network. A carrier allocation system assigns sub-carriers according to a utility function based on real-time measurements of arrival data rates and queue length variance. | 03-04-2010 |
20100086314 | Method and Apparatus for an Optical Duty Cycle for an Optical Digital Coherent System - An optical apparatus includes a quadrature phase shift keying modulator for generating a non-return-to-zero quadrature phase shift keyed NRZ-QPSK signal from a received lightwave, the modulator being driven by a radio frequency RF signal, an intensity modulator for carving the NRZ-QPSK signal to return-to-zero RZ pulses with a different duty cycle than that of the NRZ-QPSK, the intensity modulator being driven by a radio frequency RF clock signal to change the NRZ-QPSK to an RZ-QPSK signal, and an optical filter with a narrow band for filtering the signal from the intensity modulator to increase optical power that is useable by an optical digital coherent detection system. | 04-08-2010 |
20100119241 | ADAPTIVE FREQUENCY DOMAIN EQUALIZATION WITHOUT CYCLIC PREFIXES - Polarization multiplexing, optical communications systems can suffer from chromatic dispersion and polarization mode dispersion, resulting in channel delay spread. These errors can be compensated quickly and simply in the frequency domain. By obviating the need for a cyclic prefix, the complexity of the equalization can be reduced by more than a factor of twenty. | 05-13-2010 |
20100122003 | RING-BASED HIGH SPEED BUS INTERFACE - A communication system management interface includes a control master; and one or more slaves under management by the control master; wherein each device, either the control master or slave, has at least an input signal connected to an output signal of another device to form a daisy-chain. | 05-13-2010 |
20100142637 | TRANSMITTER COMPENSATION IN DECODING OF INTENSITY MODULATED OPTICAL OFDM WITH DIRECT DETECTION - A method by an optical OFDM receiver includes converting a received optical signal to an electrical signal, deriving a digital signal from the electrical signal, and emulating, with an iterative OFDM demodulator responsive to the digital signal, a transmitter effect in the received signal of lower peak clipping and top peak distortion and applying the transmitter effect to the received signal and a decision-made signal for estimating an error function to be applied to a demodulation of the received optical signal. | 06-10-2010 |
20100196009 | POLARIZATION INDEPENDENT FREQUENCY DOMAIN EQUALIZATION (FDE) FOR CHROMATIC DISPERSION (CD) COMPENSATION IN POLMUX COHERENT SYSTEMS - A method for the polarization independent frequency domain equalization (FDE) chromatic dispersion compensation on polarization multiplexing (POLMUX) coherent systems. Operationally, time domain signals are converted to frequency domain signals such that time domain convolution can be done as simple multiplications in the frequency domain. These frequency domain signals then converted back to time domain for subsequent use. The input signal size and FFT size are advantageously designed so that the output signals can be continuous with some overlap between two successive frames. | 08-05-2010 |
20100208853 | FEEDBACK ADJUSTABLE CONSTELLATION DE-MAPPER - A system and method to adjust the symbol constellation used to de-map a signal in an optical coherent communications system. A feedback de-mapper adjustment module is configured to compare average Error Vector Magnitude and Bit Error Ratio to a pre-defined table to determine when a constellation de-mapper mismatch occurs. The feedback de-mapper adjustment module then rotates the de-mapper constellation in order to compensate for phase drift. | 08-19-2010 |
20100215371 | POLARIZATION MODE DISPERSION (PMD) COMPENSATION IN POLARIZATION MULTIPLEXED CODED ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (OFDM) SYSTEMS - A receiver and method are provided. The receiver includes a detector configured to receive polarization multiplexed coded orthogonal frequency division multiplexing input sequences and generate estimates of unknown transmitted symbols in the input sequences for x- and y-polarization channels with respect to laser phase noise and PMD. A demapper coupled to the detector is configured to partially cancel polarization mode dispersion (PMD) in the input sequences by computing symbol probabilities for the estimates with respect to the laser phase noise, and averaging the symbol probabilities with respect to the laser phase noise. One or more low-density parity-check (LDPC) decoders coupled to the demapper are configured to receive bit probabilities derived from the averaged symbol probabilities and output code words based at least on the bit probabilities. The one or more LDPC decoders iteratively provide extrinsic soft information feedback to the demapper to compensate for the PMD. | 08-26-2010 |
20100232789 | Modified Michelson Interferometer Structure for Inter-Symbol Interference-Suppressed Colorless DPSK Demodulation - An optical device includes an interferometer for a received optical differential phase shift keying DPSK signal, and an equalizer integrated with the interferometer in a manner for reducing from optical filtering effects an interference by signal bits of the DPSK signal with signal bits of a contiguous DPSK signal. The interferometer is a Michelson delay interferometer type, but can also be a Mach-Zehnder delay interferometer type on fiber, waveguide or other optical structure. The equalizer is a Fabry-Perot type equalizer, but can be a ring resonator type or a fiber based equalizer. | 09-16-2010 |
20100232795 | Flow-Subcarrier Mapping in Optical Orthogonal Frequency Division Multiplexing - Each of a plurality of data flows is classified as having a respective data flow type, and each data flow is assigned to one of a plurality of subcarrier groups, based on the data flow's type, wherein each subcarrier group comprises a respective plurality of subcarriers. First data flows assigned to a first subcarrier group are transmitted exclusively on respective subcarriers in the first subcarrier group, and second data flows assigned to a second subcarrier group are transmitted together on all of the subcarriers in the second subcarrier group. | 09-16-2010 |
20100232803 | Integrated Equalizer and Michelson Interferometer Structure for Inter-Symbol Interference-Suppressed colorless DPSK demodulation - An optical device includes an interferometer for a received optical differential phase shift keying DPSK signal, and an equalizer integrated with the interferometer in a manner for reducing from optical filtering effects an interference by signal bits of the DPSK signal with signal bits of a contiguous DPSK signal. The interferometer is a Michelson delay interferometer type, but can also be a Mach-Zehnder delay interferometer type on fiber, waveguide or other optical structure. The equalizer is a Fabry-Perot type equalizer, but can be a ring resonator type or a fiber based equalizer. | 09-16-2010 |
20100232804 | METHODS AND SYSTEMS FOR POLARIZATION MULTIPLEXED MULTILEVEL MODULATION FOR OPTICAL COMMUNICATION - Multilevel soft-equalizer detectors, such as a maximum a posteriori probability (MAP) detector, suitable for use in polarization multiplexed optical communications using multilevel modulations and coherent detection are disclosed. Detection systems and methods may consider two symbols transmitted over two orthogonal polarization states as a two-component symbol, which is effective in eliminating the bit error ratio (BER) floor phenomenon introduced by conventional soft equalizers. | 09-16-2010 |
20100266282 | Parallel Digital Coherent Detection Using Symmetrical Optical Interleaver and Direct Optical Down Conversion - A method includes modulating lightwaves to provide first and second OFDM signal sidebands at a first polarization direction and first and second OFDM signal sidebands at a second polarization direction, and combining sidebands that are oppositely positioned and joined from the first and second OFDM signal sidebands at each polarization direction to provide a polarization multiplexing OFDM signal. | 10-21-2010 |
20100310257 | Systems and Methods for Transmitting Signals in Communication Networks - For each path in a first plurality of paths in said communication network, a respective first weighted path length is determined based at least in part on a number of pure wireless links in the path. From among the first plurality of paths, a second plurality of paths having first weighted path lengths less than a threshold value is selected. For each path in the second plurality, a respective second weighted path length is determined based at least in part on a number of pure optical links in the path, and from among the second plurality of paths, a transmission path is selected having a highest second weighted path length. Information is transmitted via the transmission path. | 12-09-2010 |
20100329696 | 16 Quadrature Amplitude Modulation Optical Signal Transmitter - An optical transmitter including a dividing optical coupler for dividing a lightwave onto optical paths; a first optical modulator in a first of the optical paths and driven by an I component of a first signal and a I component of a second signal for modulating the lightwave, a DC bias of the first optical modulator being at a quadrature point; a second optical modulator in a second of the optical paths and driven by a Q component of the first signal and a Q component of the second signal for modulating the lightwave, a DC bias of the second optical modulator being at the quadrature point; a phase shifter for generating a 90 degree phase shift in the Q components of the first and second signals that are modulated by the second optical coupler; and a combining optical coupler for combining the modulated lightwave from the first optical coupler and the phase shifted Q components of the first and second signals for generating a quadrature amplitude modulated signal. | 12-30-2010 |
20110020003 | Generating A 400-Gbit/s Single-Channel Optical Signal - A method for generating a 400 Gb/s single channel optical signal from multiple modulated subchannels includes carving respective modulated subchannels into return-to-zero RZ modulated subchannels having non-overlapping peaks with intensity modulators having a duty cycle less than 50%, and combining the subchannels into a single channel signal aggregating the bit rate of each of the subchannels. The subchannels are combined with a flat top optical component for increased subsequent receiver sensitivity. | 01-27-2011 |
20110052201 | MODULAR COLORLESS AND DIRECTIONLESS MULTI-DEGREE RECONFIGURABLE OPTICAL ADD/DROP MULTIPLEXER NODE WITH IN-SERVICE UPGRADEABILITY - In a dense wavelength division multiplexed optical network, an upgradeable, modular, colorless, directionless, reconfigurable add/drop multiplexer having a small form factor. By using wavelength selective switches and couplers, the above features are achieved without the need for photonic cross connects. | 03-03-2011 |
20110069954 | On Improved Optical Network Apparatus Having Optical Line Terminal Blade Protection with 1-to-N Redundancy and No-Service-Interruption - There is provided an optical network apparatus having interconnected processing gigabit passive optical network G-PON blades, a protection blade, and controller blade, the regular blades and protecting blade having a higher layer processing and switching interface to a G-PON media access control MAC coupled to PHY including serializer and de-serializer modules that are connected to respective interface modules, the improvement including a protecting 1:N signal drive and a protecting N:1 signal select driver coupled between the interface module and serializer and de-serializer modules of the protecting blade, respectively, for protecting connection to the interface module of the protecting blade. The improvement further includes a processing 1:N signal driver and a processing N:1 signal select driver coupled between the interface module and serializer and de-serializer modules of the processing G-PON blade, respectively, for protecting connection to the interface module of the processing G-PON blade and a 1:2 signal driver and 2:1 signal select driver in the interface module for providing an alternative connection to the protection blade. | 03-24-2011 |
20110069964 | Optical Signal Sideband Millimeter-Wave Signal Generation for Super-Broadband Optical Wireless Network - An optical wireless network includes an optical coupler for diverting received millimeter-wave signals comprised of an optical carrier and second order sidebands into multiple transmission paths; a downstream optical path being one of the multiple transmission paths and including an optical filter for filtering passing through the optical carrier with a single sideband, a converter for converting the optical carrier and single sideband to a corresponding electrical signal for amplification and broadcast transmission from an antenna; and an upstream path being one of the multiple transmission paths and having a filter for passing through the optical carrier only from the mm-wave signals and an intensity modulator driven by data received over the antenna to modulate the optical carrier for optical transmission to a receiving destination. | 03-24-2011 |
20110075242 | OPTICAL SIGNAL GENERATION WITH D/A CONVERTERS AND OPTICAL CLOCK PULSE STREAM - An apparatus includes an optical train pulse generator for generating continuous optical pulses each having a narrow width; a clock source having a high frequency for triggering the generator and operable as a sampling clock; a digital-to-analog converter DAC for converting an input signal from a digital signal processor, the DAC responsive to the sampling clock; a data modulator responsive to an amplified output from the DAC to modulate the continuous optical pulses from the train pulse generator; and a filter for removing higher frequency harmonics from the modulated continuous optical pulses out of the data modulator. | 03-31-2011 |
20110081151 | Generation and Coherent Detection of High-Speed Orthogonal DWDM Optical Signal - A high speed orthogonal dense wavelength division multiplexing DWDM signal generator includes a multi-peak continuous wave signal generator responsive to a light source, an optical filter for separating multi-peaks of lightwaves from the generator; and a polarization multiplexing stage responsive to the multi-peaks of lightwaves from the optical filter for providing a polarization multiplexing optical signal. The generator includes a cascaded phase modulator and intensity modulator driven by a repetitive frequency (I) to generate multiple spectral peaks, each peak being modulated by an optical modulator driven by a respective baud rate (f baud/s) electrical signal. | 04-07-2011 |
20110085494 | DATA ROUTING IN HYBRID WIRELESS COMMUNICATION NETWORKS - System(s), device(s), and method(s) are provided to route data in a mesh network of devices that can communicate wirelessly through a plurality of technologies. One or more of such devices receive broadcast message(s) from a destination device intended to receive the data, and generate a first radio link quality metric (RLQM) value based on the broadcast message(s). A source device originates and delivers a quantum of data with an embedded first RLQM value. A set of intermediate devices relays the quantum of data if a forwarding criterion is fulfilled; the forwarding criterion is based in part on the first RLQM value and a second RLQM value generated by an intermediate device in the set of intermediate devices based on the broadcast message(s). The intermediate device exploits an optical interface to transmit the quantum of data. The destination device broadcasts an acknowledgement signal in response to receiving intended data. | 04-14-2011 |
20110085803 | ROADM TRANSPONDER AGGREGATOR SYSTEMS AND METHODS OF OPERATION - ROADM node systems and methods of operation are disclosed. ROADM node systems may include transponder aggregators including transponders to add signals for switching through the ROADM node. The transponder aggregators may be constrained from adding signals on adjacent channels for simultaneous use. Further, the transponder aggregators may include an optical coupler in lieu of an optical multiplexer. The ROADM system may include a set of wavelength selective switches associated with output ports that can provide an additional filtering function for the added signals prior to transmission on a WDM network. | 04-14-2011 |
20110249969 | POWER OPTIMIZATION OF OPTICAL RECEIVERS - An optical receiver system is disclosed. The system includes a local oscillator, a mixer and a processor. The local oscillator is configured to generate a laser signal to indicate a selection of one of a plurality of channels. In addition, the mixer is configured to receive signals on the plurality of channels and to utilize the laser signal to distinguish the signal on the selected channel. Further, the processor is configured to maximize a power level difference between the laser signal and at least one of the plurality of channels based on a total number of the plurality of channels by adjusting the power of the laser signal input to the mixer to limit a noise penalty in the receiver system. | 10-13-2011 |
20110262143 | ROADM SYSTEMS AND METHODS OF OPERATION - ROADM node systems and methods of operation are disclosed. ROADM node systems may include transponder aggregators including transponders to add signals for switching through the ROADM node. The transponder aggregators include optical couplers constrained that are from coupling added signals on adjacent channels for simultaneous use. The ROADM system may include an optical interleaver that can provide an additional filtering function for the coupled signals prior to transmission of the signals on a WDM network. | 10-27-2011 |
20110286746 | Transponder Aggregator Without Wavelength Selector for Colorless and Directionless Multi-Degree ROADM Node - A method for transponder optical channel selection of optical signals from a transponder aggregator includes choosing wavelength division multiplexing channels to be dropped from a transponder aggregator receiving optical input signals, splitting all dropped wavelength division multiplexing channels into at least one transponder having a coherent receiver and transmitter, and tuning a local oscillator laser of the coherent receiver to a wavelength of one of the all dropped wavelength division multiplexing channels for selecting one of the all dropped wavelength division multiplexing channels. | 11-24-2011 |
20110310951 | COMPUTATIONALLY-EFFICIENT MIMO EQUALIZATION ALGORITHM FOR HIGH-SPEED, REAL-TIME, ADAPTIVE POLARIZATION MULTIPLEXED (POLMUX) OFDM TRANSMISSION WITH DIRECT DETECTION - A polarization-multiplexed (POLMUX) optical orthogonal frequency division multiplexing (OFDM) system with direct detection includes an adaptive dual POLMUX carrier OFDM transmitter; and a block symmetric (B-S) MIMO equalizer coupled to the adaptive dual POLMUX carrier OFDM transmitter through a standard single-mode-fiber (SSMF) feedback path. | 12-22-2011 |
20110314352 | REDUCED-COMPLEXITY LDPC DECODING - Methods and systems for reduced-complexity decoding of low-density parity-check (LDPC) information. An encoded input stream is received. The received stream is decoded with one or more reduced-complexity min-sum or a posteriori probability LDPC decoders. A v-node update rule in the reduced complexity decoder is omitted. | 12-22-2011 |
20120047415 | REVERSE CONCATENATED ENCODING AND DECODING - Methods and systems for transmitting and receiving data include reverse concatenated encoding and decoding. Reverse concatenated decoding includes inner decoding the encoded stream with an inner decoder that uses a low-complexity linear-block code to produce an inner-decoder output stream, outer decoding the inner-decoder output stream with an outer decoder that uses a low-density parity-check code to produce an information stream, and iterating extrinsic bit reliabilities from the outer decoding for use in subsequent inner decoding to improve decoding performance. | 02-23-2012 |
20120082457 | K-Means Clustered Polyphase Filtering for Sample Rate Conversion in Coherent Polarization Multiplexing Fiber Optic Systems - A method for clustered polyphase filtering input data converted from an optical signal converting input data from a serial form into a parallel form, permutating data symbols from the input data to form K clusters, passing the permutated data to an adder and multiplier for each cluster; and adding output of all K multipliers together to form an output. | 04-05-2012 |
20120099637 | SYSTEMS AND METHODS FOR PERFORMING DYNAMIC CHANNEL ESTIMATION - Systems and methods are disclosed for dynamic channel estimation in a digital receiver by performing a dynamic equalization on an incoming signal to compensate for channel distortion; independently estimating one or more channel parameters for the dynamic equalization, wherein the one or more channel parameters track channel change; determining a convolution of the channel parameters and updating the parameters for the dynamic equalization for subsequent processing of incoming signal; and providing an equalized output from the digital receiver. | 04-26-2012 |
20120213523 | OPTICAL-LAYER TRAFFIC GROOMING AT AN OFDM SUBCARRIER LEVEL WITH PHOTODETECTION CONVERSION OF AN INPUT OPTICAL OFDM TO AN ELECTRICAL SIGNAL - A method for optical layer traffic grooming includes receiving at least two optical input signals into respective optical receivers, each optical receiver having a photodetector for converting the respective optical input signal into a respective electrical signal; a grooming processor responsive to the electrical signals, the grooming processor being a radio frequency RF processor for processing the electrical signals at a subcarrier level to produce an RF orthogonal frequency division multiplexing signal OFDM signal; and modulating the groomed RF OFDM signal at a transmitter for conversion of the groomed RF OFDM into an optical signal. | 08-23-2012 |
20120251028 | Polarization-Alternating Optical Signal Generation using CSRZ Modulation - A method for optical chirp-free optical polarization modulation includes dividing a data modulated optical signal into a first optical path and a second optical path, using a Mach-Zehnder intensity modulator in the first optical path for imparting a π phase difference between adjacent symbols of the data modulated optical signal in the first optical path, adjusting a delay and amplitude of symbols of the data modulated optical signal in the second path so that the symbols in the first path and the symbols in the second path are synchronized and have substantially equal power levels, and combining the first and second optical paths so that symbols from the first and second optical paths are in orthogonal polarizations. | 10-04-2012 |
20120251117 | Method for Traffic Grooming, Wavelength Assignment and Spectrum Allocation - A method includes determining a line rate selection for a flexible optical wavelength-division-multiplexing WDM network, determining a traffic routing in said network, and determining simultaneously a channel routing, wavelength assignment and spectrum allocation in said network based on an auxiliary graph. | 10-04-2012 |
20120263467 | Polmux-OFDM-DD Transmitter and Receiver for Reduced Complexity and Overhead in Optical Access/Metro Transmission - An optical communication system includes a polarization multiplexed orthogonal frequency-division multiplexing POLMUX-OFDM transmitter for generating a POLMUX-OFDM double sideband signal, an optical processing path for processing the double sideband signal from the transmitter; an analog-to-digital convert ADC-OFDM receiver coupled to the optical processing path for receiving the double sideband signal processed by the optical path; and a block-diagonal multiple-input multiple-output MIMO equalizer responsive to the receiver for enabling correct operation for a completely random incoming signal polarization state without adaptive polarization control at said receiver, which enables complexity. | 10-18-2012 |
20120263468 | Generation of Optical Quadrature Duobinary Format Using Optical Delay - An optical method for generating an optical quadrature duobinary QDB signal includes receiving a quadrature phase-shift-keying QPSK signal, and adding a delay to the received quadrature phase-shift-keying QPSK signal to generate an optical quadrature duobinary signal. | 10-18-2012 |
20120263469 | Method for Reducing Power Consumption of a Passive Optical Network - A method for reducing energy consumption of a passive optical network includes optical network units of the network which infer their downstream queue status rather than being explicitly notified by an optical line terminal of the network. Based on the inferred queue status, the optical network units make their own sleep mode decisions without assistance from optical line terminal. Both downstream traffic inference and sleep decision making at the optical network units are based on common information possessed by optical line terminal and optical network units. Accordingly, the optical line terminal can accurately infer the status of each optical network unit if the sleep control scheme implemented at an optical network unit is known by the optical line terminal. | 10-18-2012 |
20120301142 | Optical Superchannel Method and System - Optical superchannel methods and systems that couple two or more local oscillators into a single coherent receiver front end to receive multiple optical subcarriers are shown and described. With multiple local oscillators coupled into a single coherent receiver and appropriate optical selective filtering of the superchannel signal, non-neighboring subcarriers may be received by the single coherent optical receiver. | 11-29-2012 |
20120321303 | Multiple-Symbol Polarization Switching for Differential-Detection Modulation Formats - An inventive method for multi-symbol polarization switching for differential detection optical systems includes modulating a laser source by a DQPSK modulator, driving the DQPSK modulator with a data block configured for generating multi-symbol polarization-switched DQPSK differential-encoded signals, and polarizing the multi-symbol polarization-switched DQPSK signals with a polarizing modulator whose modulation speed is based on how often polarization states vary, wherein the data block provides a bits manipulation to provide the multi-symbol polarization switching thereby enabling differential detection for recovering correct original data by a receiver. | 12-20-2012 |
20120321311 | Coherent Interleaved Polarization-Multiplexing Optical Communications with Single IQ Modulator - An inventive method for coherent interleaved polarization-multiplexing PolMux optical communications with a single IQ modulator includes modulating a light source to generate a 50% return-to-zero RZ signal pulse at a frequency Rs, driving a single IQ modulator with inphase I and quadrature phase Q data at a bit rate of sais Rs to introduce phase modulation on said 50% RZ signal pulse to produce a QPSK pulse signal with all symbols being in a same polarization state without any time overlapping; and polarization modulating said QPSK signal to alternatively convert said QPSK signal into two orthogonal polarizations states enabling an interleaving PolMux signal with a symbol rate of Rs/2. | 12-20-2012 |
20130045012 | Multi-Service Provisioning in Orthogonal Frequency Division Multiplexing-Passive Optical network OFDMA-PON - A method for multi-service provisioning in an OFDMA-PON that includes linking communicatively to a core network and bandwidth provisioning, dynamically within a single wavelength, traffic from the core network to a network of multiple virtual passive optical networks VPONs for multi-service provisioning to the VPONs. | 02-21-2013 |
20130058648 | Variable Rate Optical Transmitter Based on All-Optical OFDM Super-Channel Technology - The present invention is directed to a method including determining an appropriate power level for a phase modulator for an optimum number of subcarriers; and applying the determined appropriate power level via a controller to produce the optimum number of subcarriers, wherein the optimum number of subcarriers enables an optical-orthogonal frequency division multiplex O-OFDM based variable rate transmitter with automatic control by a controller to produce an optimum setting based on a required rate. | 03-07-2013 |
20130077972 | Sleep Control for Energy Efficiency in Ethernet Passive Optical Networks - A method sets certain downstream traffic scheduling rules at an optical line terminal OLT and certain sleep control rules at optical network units ONUs. Both downstream traffic scheduling rules and sleep control rules are common information owned by both the OLT and ONUs. The method sets the traffic scheduling rules that each ONU is allocated with some time slots every cycle if the ONU has downstream traffic. Rather than using a control message to notify ONUs with their queue status, the method lets ONUs infer whether its downstream queue is empty or not based on downstream traffic scheduling and lets the OLT infer the status of an ONU based on sleep control rules. | 03-28-2013 |
20130089323 | Optimal Combined 2R/3R Regenerators Placement Method for Line Network Topologies in Optical WDM Networks - A method for optimal combined 2R/3R regenerators placement for optical transmission includes determining an optimal placement of multiple 2R and 3R regenerators that minimizes bit error rate BER at a destination node, determining an optimal number of the 2R and 3R regenerators that minimizes a total cost while satisfying the BER at the destination node, and determining an optimal placement of the 2R and 3R regenerators along a route in the optical transmission. | 04-11-2013 |
20130089327 | Polarization Switching for Optical Fiber Communications - A method implemented in a transmission apparatus used in an optical fiber communications system for a polarization switched differential quaternary phase-shift keying (DQPSK) signal is disclosed. The method comprises splitting data into two or more data streams, inputting said two or more data streams to 1-bit DQPSK precoders to perform 1-bit DQPSK precoding, and multiplexing inphase outputs of the 1-bit DQPSK precoders to generate a first output; and multiplexing quadrature outputs of the 1-bit DQPSK precoders to generate a second output. Other methods, apparatuses, and systems also are disclosed. | 04-11-2013 |
20130094851 | Optical Spectral Shaping for Nonlinearity Enhancement in High Speed Digital Coherent Optical Transmissions - A method includes evaluating an optical signal spectrum for estimated filtering parameters of an optical spectral filtering device for shaping optical signal spectrum, determining a feedback for fine tuning the optical spectral filtering device for nonlinearity tolerance enhancement in the optical transmission system, responsive to received optical signal quality in the optical signal spectrum; and using the feedback to adjust said optical spectral filtering device for predetermined shaping and predetermined fiber nonlinearity tolerance in the optical transmission system. | 04-18-2013 |
20130148963 | Dynamic Multidimensional Optical Networking Based on Spatial and Spectral Processing - An optical network includes a multidimensional coder and modulator for handling multiple-in-multiple-out MIMO spatial lightpath properties and content of any specific supercarrier, a spatial mode multiplexer responsive to orthogonal frequency division multiplexing OFDM transmissions and the multidimensional coder, a spatial-spectral routing node coupled over a fiber link to the spatial mode multiplexer for performing switching granularity by a spatial mode reconnection, a multidimensional decoder and demodulator; and a spatial mode demultiplexer coupled over a fiber link to the spatial-spectral routing node and responsive to the multidimensional decoder and demodulator. | 06-13-2013 |
20130170825 | Solution for Hitless Protection in High-Speed OTN Framer and Front-End - In an optical communication system containing a primary line and backup line card, a method includes providing interfaces for the primary and backup line card, each line card including a transmitter and receiver; and selecting output from the transmitter from either the primary or back up line card including selecting the backup line card when the primary line card encounters a failure. | 07-04-2013 |
20130209035 | OPTICAL DISPERSION COMPENSATION MODULE USING FIBER BRAGG GRATING WITH MULTIPLE DEGREES OF FREEDOM FOR THE OPTICAL FIELD - Systems and methods are disclosed for enhancing optical communication by performing dispersion compensation in an optical fiber using a fiber Bragg grating (FBG); and providing increased degrees of freedoms (DOFs) to distinguish forward and backward propagating fields with a passive component. | 08-15-2013 |
20130216229 | ORTHOGONAL FREQUENCY DIVISION MULTIPLE ACCESS TIME DIVISION MULTIPLE ACCESS-PASSIVE OPTICAL NETWORKS OFDMA TDMA PON ARCHITECTURE FOR 4G AND BEYOND MOBILE BACKHAUL - Systems and methods are provided for network communication using wireless base stations and an optical orthogonal frequency division multiple access (OFDMA) signal generated on an optical wavelength, with the optical OFDMA signal being composed of a plurality of OFDMA subcarriers. A multi-level modulator modulates each of the plurality of OFDMA subcarriers. A single optical wavelength propagates each of the plurality of OFDMA subcarriers to different base stations; a passive optical splitter delivers the optical OFDMA signal to different base stations; and an OFDMA subcarrier de-multiplexer delivers and extracts traffic for each of the base stations in an electronic-domain, wherein the extracted traffic is remodulated in a wireless signal format. Antennas at each of the base stations transmit wireless signals, and the wireless signals are recovered and processed from the base stations. | 08-22-2013 |
20130259055 | RECONFIGURABLE BRANCHING UNIT FOR SUBMARINE OPTICAL COMMUNICATION NETWORKS - Methods and systems for optical communication in a submarine network are provided. An input signal is received from a terminal at a reconfigurable branching unit (BU), wherein the BU enables bidirectional transmission between any two terminals, and the input signal is demultiplexed into at least one individual waveband or wavelength using at least one demultiplexer. Each demultiplexed waveband is passed through optical switches, with corresponding optical switches for the same demultiplexed waveband provided for transmission in the reverse direction. Independent per-waveband switching is performed using a demultiplexer-switch-multiplexer (DSM) architecture. Each demultiplexed waveband is multiplexed at each output port using at least one multiplexer to combine signals from different sources, and combined signals are transmitted to a destination terminal. | 10-03-2013 |
20130259174 | Method and System for Pilot-Based Time Domain Phase Noise Mitigation for Coherent Receiver - A method for phase noise mitigation for a coherent receiver in either an OFDM or single carrier based transmission system including applying a frequency offset and coarse phase noise compensation based on a radio frequency RF tone or using a phase lock loop PLL m-th power procedure, responsive to a signal from a digital signal processed transmission with an added pilots signal over an optical system, applying fine phase noise compensation based on comparison of the pilots signal in a time domain, removing the pilots, and demodulating the remaining pilotless signal. | 10-03-2013 |
20130259474 | TRANSPONDER AGGREGATOR-BASED OPTICAL LOOPBACK IN A MD-ROADM - The present principles are directed to a transponder aggregator-based optical loopback in a multi-degree colorless, directionless, contention-less, reconfigurable optical add/drop multiplexer. The multiplexer includes a reconfigurable optical add/drop multiplexer section for performing connect operations for wavelength division multiplexing signals among all degrees. The section has a plurality of subsections. Each of the subsections corresponds to a respective one of the degrees and has an optical separator at an input side and an optical combiner at an output side. The multiplexer further includes a transponder aggregator section having a split-and-select switch-based transponder aggregator. The multiplexer also includes an optical line loopback having a connection path between the optical separator at the input side and the optical combiner at the output side of at least one of the subsections. | 10-03-2013 |
20130259475 | RECONFIGURABLE BRANCHING UNIT FOR SUBMARINE OPTICAL COMMUNICATION NETWORKS - Methods and systems for optical communication in a submarine network are provided. An input signal is received from a terminal at a reconfigurable branching unit (BU), and the input signal is split into at least two parts, with one part being associated with one or more trunk terminals and another part being associated with one or more branch terminals. Each of one or more spectrum channels are selected and individually switched to one of a plurality of paths using at least one wavelength selective switch (WSS), with the at least one WSS being configured to transmit the one or more spectrum channels to their respective target output port and to combine signals switched to a specific port into a wavelength division multiplexing (WDM) signal. Individual spectrum channels are filtered out using at least one wavelength blocker (WB). | 10-03-2013 |
20130272711 | Light-Tree Provisioning for Multicast Traffic in Flexible Optical WDM Networks - Hybrid application of the generic evolution and simulated annealing methods are used to solve routing, wavelength assignment, and spectrum allocation sub-problems of a light-tree establishment problem in a flexible wavelength division multiplexing FWDM optical network. | 10-17-2013 |
20130343755 | Software-Defined Optical Network - A software-defined (SD) optical network is disclosed. An SD optical line terminal (OLT) includes a global SD controller, one or more SD OLT drivers connected to the global SD controller, and an underlying hardware component connected to each of said one or more SD OLT drivers. An SD optical network unit (ONU) includes a local SD controller, one or more SD optical network unit (ONU) drivers connected to the local SD controller, and an underlying hardware component connected to each of said one or more SD ONU drivers, wherein the local SD controller manages said one or more SD ONU drivers by issuing commands communicated to said one or more SD ONU drivers, and wherein each of said one or more SD ONU drivers implements a required function on the underlying hardware component. Other apparatuses, systems, and methods also are disclosed. | 12-26-2013 |
20140056371 | MIMO-OFDM-Based Flexible Rate Intra-Data Center Network - An optical network includes receiving inter-rack traffics from transmitter racks, converting by transmitters the inter-rack traffics to respective wavelength division multiplexing WDM optical signals, receiving and routing by a cyclic interleaver the optical signals from the transmitters to output ports in a cyclic manner, converting respective routed optical signals from the cyclic interleaver into respective electrical signals, and demodulating OFDM formats from respective converted optical signals containing signals for respective receiver racks. | 02-27-2014 |
20140056585 | Next Generation Optical Access Network with Centralized Digital OLT - An optical access network with centralized digital optical line termination OLT including an optical line termination unit having a digital transmitter and a coherent receiver for downstream signal transmitting and upstream signal receiving, and at least one optical network unit ONU with transceiver functions for communicating with the OLT over an optical path, the ONU including intensity modulation and single photodiode detection, wherein the digital transmitter includes digital signal processing DSP, digital-to-analog conversion DAC and analog-to-digital conversion ADC functions that can be shared by all multiple ones of the ONU in the network, the DSP reducing or removing dispersion and non-linearity effects in the network and the coherent receiver enabling performance of the downstream stream signal transmitting to match that of the upstream signal receiving in the OLT. | 02-27-2014 |
20140079164 | Full-Range Pilot-Assisted Frequency Offset Estimation for OFDM Communication Systems - A training symbol with two identical halves as well as a pilot-tone at a center frequency is used for both timing synchronization and carrier frequency offset estimation. A timing synchronization is achieved by finding a peak of a cross-correlation function of the two halves in the first symbol. A fraction part of the frequency offset FO is then calculated from a phase difference between the two halves of the first training symbol. Then, the received signal is compensated for the fraction part of FO, and, an integer part of the FO is obtained by counting the shifted positions of the pilot-tone peak in the frequency domain. | 03-20-2014 |
20140095685 | Generic Centralized Architecture for Software-Defined Networking with Low Latency One-Way Bypass Communication - A generic centralized, software-defined networking configuration for connecting network is defined as a generic multi-layer topology network entities interconnected either vertically or horizontally regardless of the employed network topology/graph). This centralized configuration enables establishment of a connection between any two networking entities by 1) bypassing intermediate protocol layers and 2) eliminating any handshaking between peer elements of the same layer. The centralized software-defined controller notifies in parallel all involved network entities along a connection path to take all necessary actions (i.e. reconfiguration) to establish the new connection. The centralized controller has authority to control only entities that are software-defined SD. | 04-03-2014 |
20140099103 | LDPC-CODED MODULATION FOR ULTRA-HIGH-SPEED OPTICAL TRANSPORT IN THE PRESENCE OF PHASE NOISE - Methods and systems for decoding a signal include compensating for impairments in a received signal using at least carrier phase estimation, where residual phase error remains after compensation; calculating symbol log-likelihood ratios (LLRs) for symbols in the compensated signal using Monte Carlo integration; demapping the symbols in the compensated signal using the symbol LLRs and extrinsic information from signal decoding to produce one or more estimated codewords; and decoding each estimated codeword with a decoder that generates a decoded codeword and extrinsic information. | 04-10-2014 |
20140099126 | Pair-wise Symbol Correlated High Receiver Sensitivity Modulation Format - The invention is directed to a novel computer implemented method for finding a modulation format that has better receiver sensitivity than modulation formats that are currently being used, with a correlated symbol modulation in which neighboring symbols are coded and decoded together to increase receiver sensitivity. | 04-10-2014 |
20140099128 | Inter-band cross-phase modulation compensation for the mitigation of intra-channel nonlinear impairments in optical fiber transmission - An optical communication system includes a digital signal processer coupled to the coherent receiver, said coherent receiver including a nonlinearity compensation module for compensating for nonlinear effects in fiber in the optical link for increasing capacity or transmission distance of the fiber, the nonlinearity compensation module includes a spectral slicing of the signal into bands, computing nonlinear interaction between the bands with parameters opposite to those of the fiber to reverse the non-linear effects in the fiber, and only certain nonlinear interactions between bands are considered thereby reducing complexity of the nonlinearity compensation. | 04-10-2014 |
20140101512 | ADAPTIVE LDPC-CODED MULTIDIMENSIONAL SPATIAL-MIMO MULTIBAND GENERALIZED OFDM - Systems and methods of transmitting includes one or more low-density parity-check (LDPC) encoders configured to adaptively encode one or more streams of input data by adjusting error correction strength based upon channel conditions. One or more mappers are configured to map one or more encoded data streams to symbols by associating bits of the symbols to points of an optimum signal constellation design (OSCD) based on one or more encoded data streams, the OSCD being decomposed into two or more sub-constellations. A spectral multiplexer is configured to combine symbol streams for the one or more encoded data streams to provide a plurality of spectral band groups. A mode multiplexer is configured to combine spectral contents of the plurality of spectral band groups allocated to a plurality of spatial modes for transmission over a transmission medium. | 04-10-2014 |
20140147120 | Grooming Multicast Traffic in Flexible Optical Wavelength Division Multiplexing WDM Networks - The present invention is directed to a solution for grooming multicast traffic in flexible optical wavelength division multiplexing WDM networks. The invention includes a solution for grooming multicast traffic in flexible optical wavelength division multiplexing networks into a solving a multicast routing sub-problem, solving a a grooming sub-problem; and solving a wavelength assignment and spectrum allocation sub-problem. | 05-29-2014 |
20140178071 | GENERATION OF POLARIZATION-ALTERNATED QPSK FORMAT - Methods, structures and systems for generating different polarization multiplexed signals wherein the drivers of the modulators are generic while a software-controlled manager allows the carrying of any standard 10 G/40 G/100 G data while—at the same time—being adaptively adjustable according to specific link requirements and users' requests in both dispersion-managed and uncompensated links. | 06-26-2014 |
20140205283 | MULTIDIMENSIONAL CODED-MODULATION FOR HIGH-SPEED OPTICAL TRANSPORT OVER FEW-MODE FIBERS - Systems and methods for data transport are provided which encode streams of data using low density parity check (LDPC) encoders and map data streams to symbols, by assigning bits of symbols to a signal constellation and associating bits with constellation points. Constellation points are generated using a D-dimensional optimum signal constellation design (OSCD) method. The OSCD determines an optimum source distribution for an optical channel, generates D-dimensional training sequences from the optimum source distribution, determines new signal constellation points as the center of mass for each D-dimensional cluster of points, and repeats these steps until convergence or until a predetermined number of iterations is reached. Coordinates obtained by the D-dimensional OSCD method are stored in a look-up-table (LUT), points are selected from the LUT using encoded data streams, coordinates are input into a D-dimensional modulator after digital-to-analog conversion (DAC), and a modulated signal is transmitted over an optical medium. | 07-24-2014 |
20140205286 | Multi-Direction Variable Optical Transceiver - An optical transceiver including a multi-direction variable transmitter including multiple outputs with different subcarriers being directed to different ones of the outputs to go to different directions in a network, and a multi-direction variable receiver for receiving multiple inputs thereby enabling transmission direction in a network with the transceiver at subcarrier granularity and avoiding entire super-channel granularity and enabling unused subcarriers to be utilized for traffic in other directions or destinations and making switching granularity finer for flexibility in the network. | 07-24-2014 |
20140208185 | RATE ADAPTIVE IRREGULAR QC-LDPC CODES FROM PAIRWISE BALANCED DESIGNS FOR ULTRA-HIGH-SPEED OPTICAL TRANSPORTS - Systems and methods for data transport include encoding one or more streams of input data using one or more Quasi-Cyclic Low Density Parity Check (QC-LDPC) encoders; controlling irregularity of the QC-LDPC encoded data while preserving the quasi-cyclic nature of the LDPC encoded data and eliminating the error floor phenomenon. A parity-check matrix may be partially reconfigured to adapt one or more code rates; and one or more signals are generated using a mapper, wherein the output of the mapper is modulated onto a transmission medium. One or more streams of input data are received, and the streams are decoded using one or more QC-LDPC decoders. | 07-24-2014 |
20140212135 | Switching for a MIMO-OFDM Based Flexible Rate Intra-Data Center Network - A communication system enabling a switching procedure for a multiple-input multiple-output orthogonal frequency division multiplexing (MIMO OFDM) based flexible rate intra-data center network DCN, includes a MIMO OFDM DCN with optical burst switching OBS capability, an optical burst switching OBS procedure for influencing the MIMO OFDM DCN, and a centralized control configuration coupled to the MIMO OFDM DCN and enabling a software defined network SDN configuration in the communication system. | 07-31-2014 |
20140219653 | MODIFIED ORTHOGONAL POLYNOMIALS BASED HYBRID CODED-MODULATION FOR MULTI-TB/SECOND OPTICAL TRANSPORT - A system and method for transmitting data, including one or more Low Density Parity Check (LDPC) encoders configured to encode one or more streams of input data; a signal constellation generation module configured to generate one or more signal constellations; one or more modulators configured to generate one or more signals using hybrid multidimensional coded modulation; a modified orthogonal polynomial generation module configured to generate modified orthogonal polynomials for use as electrical basis functions; and one or more mode-multiplexers and transmitters configured to mode-multiplex and transmit one or more LDPC-coded data streams over a transmission medium. | 08-07-2014 |
20140241717 | Dynamic Wavelength Virtualization and/or On-Demand Flow Provisioning in Optical Networks - A network apparatus used in an optical network is disclosed. The network apparatus includes one or more first tunable and temperature controlled (TTC) lasers, one or more transmitters each of which is connected to one of said one or more TTC lasers, one or more second TTC lasers, one or more digital signal processing (DSP) transponders (TPNDs) each of which is connected to one of said one or more second TTC lasers, one or more receivers, and a controller to control said one or more transmitters and said one or more DSP TPNDs, wherein said one or more transmitters defragment an optical access spectrum, and said one or more DSP TPNDs exploit a newly available spectrum. Other apparatuses, systems, and methods also are disclosed. | 08-28-2014 |
20140241720 | LATCHING OPTICAL SWITCH AND SUBSYSTEM USING BISTABLE LIQUID CRYSTAL - A submarine network includes a submarine network with a branching unit BU for splitting or combining a signal between a main trunk path and a branch path for allowing signals from different paths to share a same fiber optic path, said BU and submarine network normally having a fixed and predetermined wavelength arrangement preventing reconfigurability of the submarine network, and a latching wavelength selective switch WSS or wavelength blocker WB in the branching unit for splitting or combining the signals between the main trunk path and branch path to enable a latching capability and enable reconfigurability of the branching unit BU, the latching WSSS being a bistable liquid crystal based material without moving parts for increased stability and lower power consumption over use of conventional mono-stable liquid crystal LC switches in a submarine network. | 08-28-2014 |
20140269980 | Look-Up Table Based Digital Filter Array Using Digital Transmitter - Disclosed are structures and methods for slicing a broadband signal into multiple, narrower bandwidth sub-bands through the use of a look-up table (LUT). An input broadband signal is first loaded by a pre-defined LUT. The LUT is designed with multiple parallel outputs, wherein each output is one individual sub-band. | 09-18-2014 |
20140270759 | ULTRA-HIGH-SPEED OPTICAL TRANSPORT BASED ON ADAPTIVE LDPC-CODED MULTIDIMENSIONAL SPATIAL-SPECTRAL SCHEME AND ORTHOGONAL PROLATE SPHEROIDAL WAVE FUNCTIONS - Systems and methods for transmitting data, including encoding one or more streams of input data using one or more adaptive Low Density Parity Check (LDPC) encoders, wherein the encoders generate one or more signal constellations; modulate one or more signals using hybrid multidimensional coded modulation; apply orthogonal prolate spheroidal wave functions as electrical basis functions; generate one or more spectral band group signals by selecting and combining two or more spectral band groups with center frequencies that are orthogonal to each other; and spectral-mode-multiplex and transmit the one or more adaptive LDPC-coded data streams including the one or more spectral band group signals combined into corresponding spatial modes over a transmission medium. | 09-18-2014 |
20140301733 | ELASTIC CLIENT INTERFACE FOR TUNABLE OPTICAL TRANSPONDER - There are provided an optical transponder having a first end and a second end, as well as an electric switch having the transponder. The transponder includes an optical interface, at the first end, having a variable rate optical transmitter and a variable rate optical receiver to respectively transmit and receive signals using at least one of different bandwidths and different bit rates. The transponder further includes an electrical interface, at the second end, having an electrical interface throughput matching an optical capacity of the optical interface. The transponder also includes a processor for controlling the optical capacity. | 10-09-2014 |
20140308037 | Optical Network Switching Using N:N Transponder Through Time-Domain Multiplexing and Burst Mode Access - A network switch is disclosed with each port having the function of: electrical processing and optical modulation; electrical processing has the ability to identify packet or frame destination; burst mode transmission and receiving capability; uses its pre-assigned time slot to send to the corresponding destination, or receive from the expected source. | 10-16-2014 |
20140334814 | Adaptive Optical Amplifier for WDM Systems - An optical amplifier that uses software-defined optical networking (SDON) technology, with a centralized controller and flexible physical hardware (the adaptive amplifier here) to optimize the power distribution among different WDM channels in the amplifier. It considers the detailed information for each channel through the information from centralized controller. It is suitable for both single line rate and mixed line rate system, and is suitable for a wavelength division multiplexing WDM system with the same signal type or different signal types. | 11-13-2014 |
20140365835 | Receiver Bit Alignment for Multi-Lane Asynchronous High-Speed Data Interface - The invention uses a PRBS pattern generated by transmitter (serializer) as training At the receiver side, following receiver outputs, a synchronous capturing module is used to capture multiple lanes simultaneously. The captured data is used to calculate the PRBS distance for different lanes. After the distances are obtained, the one with largest latency is used as a reference, to calculate the relative latency with each other lane. This relative latency is further used to calculate the number of shifts for Barrel Shifter and word shifter. | 12-11-2014 |
20140379926 | Compute Followed by Network Load Balancing Procedure for Embedding Cloud Services in Software-Defined Flexible-Grid Optical Transport Networks - A method entails an efficient procedure, namely Compute followed by Network Load Balancing (CNLB), that first maps virtual nodes over physical nodes while balancing computational resources of different types, and finally, maps virtual links over physical routes while balancing network spectral resources | 12-25-2014 |
20140379927 | Network Followed by Compute Load Balancing Procedure for Embedding Cloud Services in Software-Defined Flexible-Grid Optical Transport Networks - A method for solving a cloud embedding problem includes first mapping virtual links over physical links followed by virtual nodes over physical nodes. The inventive method entails an efficient procedure, namely network followed by compute load balancing (NCLB), that first maps virtual links over physical links while balancing network resources, and finally, maps virtual nodes over physical nodes while balancing different types of computational resources. | 12-25-2014 |
20150043330 | END-TO-END HITLESS PROTECTION IN PACKET SWITCHED NETWORKS - A method and system are described for providing hitless protection in a packet switched network having source nodes and destination nodes. The method includes enabling a working path and a protecting path between the source and destination nodes. The working path is non-overlapping with respect to the protecting path. The method further includes replicating traffic in a given one of the source nodes to generate replicated traffic. The method also includes forwarding the traffic and the replicated traffic through a working path and a protecting path, respectively, from the given one of the source nodes to a particular one of the destination nodes. The method additionally includes delivering a hitless-protected service in the particular one of the destination nodes by selecting traffic packets received from either the working path or the protecting path. | 02-12-2015 |
20150043331 | ADDING LINK AGGREGATION GROUP TO HITLESS PROTECTION IN PACKET SWITCHED NETWORKS - A method is provided for traffic aggregation in a hitless protected packet switched network having source and destination nodes. The method includes enabling a working path and a protecting path between the source and destination nodes. The working path is non-overlapping with respect to the protecting path. The method includes generating, using a processor, internal marker packets at working and protecting input ports of the source nodes. Each market packet represents a respective marker time period. The method includes transmitting the marker packets to working and protecting output ports of the source nodes, by the working and protecting input ports of the source nodes. The method includes selectively aggregating, at each of the working and protecting output ports of the source nodes, hitless traffic sent from different working and protecting inputs ports of the source nodes to provide an aggregated flow there from, responsive to the marker packets. | 02-12-2015 |
20150043680 | Rhombic-QPSK Modulation for Improved Tolerance to Nonlinearity in Fiber Communication Systems - This invention proposes an alternative modulation format for channels that present improved performance when such channels co-propagate with existing intensity modulated channels. This modulation format is named Rhombic-QPSK (R-QPSK) and it is designed in such a way that it presents more tolerance to phase noise created by the nonlinear interaction with the legacy channels. | 02-12-2015 |
20150043920 | SUBMARINE RECONFIGURABLE OPTICAL ADD/DROP MULTIPLEXER WITH PASSIVE BRANCHING UNIT - Systems and methods for data transport, including submarine reconfigurable optical add/drop multiplexers, branching units configured to receive signals from trunk terminals (TTs), and dummy light filters configured to pass useful signals through the filters, and to reflect dummy light. Optical interleavers are configured to separate useful signals into two or more groups of optical channels, and the optical channels are set to a frequency of either a left or a right portion of a total channel bandwidth. De-interleavers merge signal groups together from trunk terminals, and lasers at each of the transponders at the source terminals are configured to adjust a destination of a channel by fine tuning a frequency or wavelength of the one or more signals. | 02-12-2015 |
20150043927 | Combining I-Q and/or PolMux Optical Receiver to Enable Single Detector - A method for reducing optical components at a receiver which include converting an input signal at a receiver to include an interleaving of alternate signal diversity components, the signal diversity components including phase diversity when the converting includes 0 and 90 degree interleaving and the signal diversity components include polarization diversity interleaving when the converting includes interleaved orthogonal polarizations, and combining the signal diversity components for enabling a single photo detection at the receiver to detect the alternative signal diversity components for subsequent analog-to-digital conversion. | 02-12-2015 |
20150046768 | ENCODING METHOD AND SYSTEM FOR QUASI-CYCLIC LOW-DENSITY PARITY-CHECK CODE - A method and system are provided. The method includes applying a quasi-cyclic matrix M to an input vector X of encoded data to generate a vector Y. The method further includes applying a matrix Q to the vector Y to generate a vector Z. The method also includes recursively generating, using a processor, parity check bits P for the encoded data from the vector Z and an identity matrix variant I. The encoded data includes quasi-cyclic low-density parity-check code. The identity matrix variant t is composed of Toeplitz sub-matrices. | 02-12-2015 |
20150055664 | RECONFIGURABLE AND VARIABLE-RATE SHARED MULTI-TRANSPONDER ARCHITECTURE FOR FLEXIBLE ETHERNET-BASED OPTICAL NETWORKS - Systems and methods for data transport, including receiving one or more signals into a reconfigurable and flexible rate shared rate multi-transponder network architecture, wherein the network architecture includes one or more transponders with multiple line side interfaces and one or more client side interfaces. The transponders are configured to map one or more signals to multiple parallel Virtual Ethernet Links, remove idle characters from the one or more signals, buffer one or more blocks of characters using an intermediate block buffer, activate and deactivate one or more portions of input/output electrical lanes of an Ethernet module, multiplex and demultiplex the one or more signals to and from the input/output electrical lanes to enable sharing of a single optical transceiver by multiple independent signals, and insert blocks of idle characters to enable transmission over a lower rate transmission pipe. | 02-26-2015 |
20150071636 | HITLESS SERVICE IN A VARIABLE RATE OPTICAL TRANSPONDER - Methods and systems for variable rate control include determining a new communications rate in response to measured data traffic patterns. A receive change message is transmitted to a receiver that triggers the receiver to wait for an end of transmission (EoT) message and to set a new communications rate. A transmit change message is transmitted to a transmitter that triggers the transmitter to send the EoT message to the receiver, to set the new communications rate, and to send a start of transmission (SoT) message to the receiver before resuming data communications. | 03-12-2015 |
20150085647 | Eliminating External Buffer for Hitless Protection by Using Channelized Flow Control - A packet switched communication system to support hitless protection includes a packet processor; a traffic manager with a buffer sized to compensate a maximum skew of each hitless path pair of a working path and a protecting path; and a hitless processor positioned between the packet processor and the traffic manager, wherein an interface between hitless processor and traffic manager has flow control to start or stop (XON/XOFF) traffic. | 03-26-2015 |