Infinera Corporation

Other

Ting-Kuang Chiang

David F Welch

Vincent G Dominic

Fred A Kish, Jr

Drew Daniel Perkins

Edward Everett Sprague

Radhakrishnan L Nagarajan

Stephen G Grubb

Charles H Joyner

Robert B Taylor

Prasad Paranjape

Matthew L Mitchell

Richard P Schneider

Mark Missey

Frank H Peters

Atul Mathur

Parthiban Kandappan

Daniel P Murphy

Marco Sosa

Alan C Nilsson

Biao Lu

Tulasi Veguru

Jan Bialkowski

Vinod Narippatta

Jeffrey Bostak

Scott Pringle

Marco E Sosa

Han Henry Sun

Rajan Rao

Scott Allen Young

Jonas Webjorn

Sandy Thomson

Chung Kuang Chin

Radhakrishna Valiveti

Yuejian Wu

Michael Timothy Kauffman

Ahmed Awadalla

Christopher Liou

Mark Tehmin Yin

Satish K Sridharan

Donald J Pavinski

Fred A Kish

Michael D Jarchi

Mats Plantare

Robert Grencavich

Konstantin Saunichev

Mallikarjun Chillal

Gopal Rao

Vinh D Nguyen

Donald J Pavinski, Jr

Curtis Villamizar

Steven G Grubb

Gus Elmer

Sofia Amado

Aroutchelvame Mayilavelane

Christopher Fludger

Mark J Missey

Millikarjun Chillal

Consistent with the present disclosure, multiple forward error correction (FEC) encoders are provided for encoding a respective one of a plurality of data streams. A mechanism is provided to mix or interleave portions of the encoded data such that each subcarrier carries information associated with each data stream, as opposed to each subcarrier carrying information associated with only a corresponding one of the data streams. As a result, both higher SNR and low SNR optical subcarriers carry such information, such that errors occurring during transmission are distributed and not concentrated or limited to information associated with a single data stream. Accordingly, at the receive end, each FEC decoder decodes information having a similar overall error rate. By balancing the error rates across each FEC encoder/decoder pair, the overall ability to correct errors improves compared to a system in which mixing or interleaving is not carried out.

Methods and apparatus for sub-carrier interleaving to improve overall forward error correction

Comprises aggregating data received by a first number of server ports of an edge switch. The server ports operate at a first data speed. The aggregated data is distributed into a plurality of virtual lanes with each virtual lane carrying a portion of the aggregated data at a second data speed less than the first data speed.

Data center interconnect

Systems, methods, devices, and other implementations for minimizing latency asymmetries and variations in a bi-directional link between two nodes in a communication system are described. To determine a variable latency for communication between two network nodes, a transmitting node can insert a line marker and a client marker into the data to be transmitted to the receiving node. The line marker and client marker can be inserted into the data at different portions or by different components of a transmitter. The receiving node can receive the transmitted data and extract the line marker and client marker. A delay associated with the line and client markers (Tc-T) in the transmission device and a delay between the reception of the line and clien markers (Rc-R) at the receiving node can be used to determine the variable latency.

Dual marker based latency measurement

Optical subcarriers may be employed to transmit data in a point-to-multi-point network whereby a hub node including a network switch receives such data from a client and transmits information indicative of such data to multiple leaf or network nodes, where data intended for such leaf node is output. Often the rate at which data is supplied to the hub node is different than the rate at which information indicative of the data is transmitted. Moreover, the client data may have a format that is different than that associated with the transmitted information indicative of the client data. Consistent with the present disclosure, client data is inverse multiplexed to lower data rate streams and then multiplexed to a plurality of inputs, each of which corresponding to a respective optical subcarrier. Information indicative of the data may be allocated to multiple subcarriers, if the a single carrier lacks sufficient capacity or bandwidth to meet the bandwidth requirements of the leaf node. Buffer circuits may also be employed to 'shape' or delay the outputs or flows of the multiplexer so that data is fed, for example, to a transmit portion of chipof the network switch at a uniform rate rather than in non-uniform data bursts, which, under certain circumstances, could exceed the capacity of such transmit portion. In a further example, leaf nodes include circuitry for monitoring the amount of received data, and, if such received exceeds a certain threshold, a request is sent from the leaf node to the hub to transmit data at a rate equal to or substantially equal to the received data rate. As a result, symmetric data flows may be achieved whereby the leaf nodes transmit and receive data at the same or substantially the same rate.

Network switches systems for optical communications networks

Consistent with the present disclosure, an optical switch is provided that switches multiple wavelength division multiplexed (WDM) optical signals. Each of the WDM signals includes optical signals having the same wavelengths. The WDM signals are supplied to optical splitters, which supply power split portions of the WDM signals to corresponding optical gates. Groups of the optical gates are associated with a corresponding switching block, which may include a cyclical arrayed waveguide grating (AWG), and the optical gates within each group are controlled so that one gate passes a received WDM signal portion while the remaining optical gates in the group are in a blocking configuration. As a result, the WDM portion received by the non-blocking gate is demultiplexed in the switching block and each of the wavelength components that constitute the selected WDM portion are supplied to corresponding outputs within the switching block. In a later time interval, a different optical gate may be rendered non-blocking so that a different WDM signal portion, supplied from a different optical splitter and carrying different information over the same wavelengths, may be input to the switching block. Thus, by controlling the optical gates, different WDM signal portions may be switched to, and thus demultiplexed by, a particular switching block. In addition, portions of the same WDM signal may be selectively supplied to different AWGs by appropriately control of the optical gates.

High-capacity switch

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 channel under test to a corresponding segment within the deskew channel and identifying a time differential between the two segments.

Channel skew identification and notification

A propagation delay in the transmission of a frame from an initiator node to a peer node is determined by initially identifying a frame number and byte offset of a first incoming frame from the peer node at a time when the initiator node outputs a portion of a transmitted frame. The portion of the transmitted frame may be the first byte of a sub-frame within the transmitted frame. At the peer node, the frame number and byte offset of a second frame to be supplied to the initiator node is identified at a later time when the frame portion transmitted by the initiator node is received by the peer node, and such information is transmitted to the initiator node. Thus, since the frames output and received by the initiator node are typically of fixed duration, the frame number and byte offset of the incoming frame represent the time when the initiator node outputs the frame portion (a transmit time). In addition, the frame number and byte offset of the second frame represents the time at which the frame portion is received by the peer node (a receive time). Accordingly, by comparing the frame numbers and byte offsets of the first and second frames received from the peer node, a difference between transmit and receive times or propagation delay can be obtained.

Method and apparatus for determining propagation delay in a network

Consistent with the present disclosure, client data, which may include multiplexed data sub-streams, is supplied to an ingress node of a network. Each sub-stream typically has a corresponding data rate, i.e., an original data rate, prior to multiplexing. The client data is encapsulated in a plurality of successive frames that are output from the ingress node and propagate, typically through one or more intermediate nodes, to an egress node. At the egress node, data rates associated with the sub-streams included in each frame are determined based on the amount of client data in each frame. The data rates are then averaged over a given number of frames to thereby filter any wander or deviation in the client data rate. Based on the averaged data rate, justification opportunities are added to the client data in each sub-stream, which are then multiplexed into frames that are output from the egress node. By including the justification opportunities, the effective rate of each sub-stream may be set equal to the original data rate when the sub-streams are demultiplexed after being output from the egress node. An advantage of the present disclosure is that the justification opportunities, are not generated based solely on clock signals generated by PLL circuits. As a result, fewer PLL circuits are required, thereby simplifying system design and minimizing power consumption.

Clocking of client signals output from an egress node in a network

Embodiments of the present invention compensate for skew across a wavelength division multiplexed network. The network is a wavelength division multiplexed optical transport network. The skew compensation can be performed electrically or optically. It can be performed on the transmission side of the network, the receiver side of the network or at any intermediary node on the network.

Communication network with skew compensation

A forward error correction (FEC) communication device that includes a transmitter photonic integrated circuit (TxPIC) or a receiver photonic integrated circuit (RxPIC) and a FEC device for FEC coding at least one channel with a first error rate and at least one additional channel with a second error rate, wherein the first error rate is greater than the second error rate. The TxPIC chip is a monolithic multi-channel chip having an array of modulated sources integrated on the chip, each operating at a different wavelength, wherein at least one of the modulated sources is modulated with a respective FEC encoded signal. The TxPIC also includes an integrated wavelength selective combiner for combining the channels for transport over an optical link.

Forward error correction (FEC) enabled photonic integrated circuit (PIC) chips with multiple signal channels

A method includes receiving client data; extracting overhead data from the client data; mapping the client data into one or more frames, where each of the one or more frames has a frame payload section and a frame overhead section, where the client data is mapped into the frame payload section of the one or more frames; inserting the overhead data into the frame overhead section of the one or more frames; transporting the one or more frames across a network; extracting the overhead data from the frame overhead section of the one or more frames; recovering the client data from the one or more frames; inserting the extracted overhead data into the recovered client data to create modified client data; and outputting the modified client data.

Providing access to client overhead while transparently transmitting the client signal

The present invention provides a system, apparatus and method for modularly adapting a network node architecture to function in one of a plurality of potential node types. The architecture includes a configurable switching element, integrated optics, and a plurality of modules that allow a 'type' of node to be adapted and configured within the base architecture. The module interfaces may be optical or electrical and be used to construct various different types of nodes including regenerators, add/drop nodes, terminal nodes, and multi-way nodes using the same base architecture.

Modular adaptation and configuration of a network node architecture

A network may include an ingress node that is configured to receive a client signal having a client rate that is one of a multiple different client rates, asynchronously map the client signal into a first frame of a first rate, asynchronously map the first frame into a second frame of a second rate, and output the second frame on the network; an intermediate node that is configured to receive the second frame, recover the first frame from the second frame, asynchronously map the first frame into a third frame of a third rate, and output the third frame on the network, where the intermediate node does not recover the client signal from the first frame; and an egress node that is configured to receive the third frame, recover the first frame from the third frame, recover the client signal from the first frame, and output the client signal.

Dual asynchronous mapping of client signals of arbitrary rate

Consistent with the present disclosure, circuitry may be provided in an optical receiver that can determine a bit error rate (BER) associated with an incoming signal by dividing the number of errored bits in a frame alignment signals (FAS) by the number of bits in the FAS. Accordingly, although an optical signal may be severely degraded and forward error correction (FEC) cannot be performed, a BER may be obtained if the FAS can be identified. The BER can then be used in a feedback loop to control various optical or electrical components in the receiver to improve or reduce the BER to a level, for example, at which FEC can be performed.

Method and system for control of communication equipment based on a bit error rate derived from a frame alignment signal

A photonic integrated circuit (PIC) chip comprising an array of modulated sources, each providing a modulated signal output at a channel wavelength different from the channel wavelength of other modulated sources and a wavelength selective combiner having an input optically coupled to received all the signal outputs from the modulated sources and provide a combined output signal on an output waveguide from the chip. The modulated sources, combiner and output waveguide are all integrated on the same chip.

Transmitter photonic integrated circuit (TxPIC) chip

Growing community of inventors

Saratoga, CA, United States of America

Ting-Kuang Chiang