Nokia Solutions and Networks Oy

Sail Internet, Inc.

Ikanos Communications, Inc.

Amitkumar Mahadevan

Georgios Ginis

Jochen Maes

Noriaki Kaneda

Kevin Dean Fisher

Nicholas Philip Sands

Yannick Lefevre

Doutje Van Veen

Vincent Etienne Houtsma

Werner Van Hoof

Vincent Houtsma

Doutje T Van Veen

Carl Mertens

Adriaan De Lind Van Wijngaarden

Michael Fivez

Paul Cautereels

Michiel Verplaetse

Michaël Fivez

Edward Harstead

Xia (Sharon) Wan

Yannnick Lefevre

An optical network unit (ONU) includes a transmitter and receiver to optically communicate with an optical line terminal (OLT) of a passive optical network. The ONU is configured to send an acknowledgment message to the OLT in response to a burst-profile message unicast by the OLT. The acknowledgement message indicates unsupported forward error correction (FEC) code in response to the burst-profile message identifying an FEC code for upstream transmission and the ONU not supporting the FEC code for upstream transmission to the OLT.

Acknowledgment-based flexible FEC selection

An optical line terminal (OLT) in flexible passive optical network (PON) transmits a downstream signal with two or more modulation formats, wherein at least one of the modulation formats is a modified PAMx modulation format and wherein x is greater than 2. The modified PAMx modulation encodes data bits such that the probability of at least one predetermined transition between amplitude levels is modified. Furthermore, an optical network unit (ONU) in the flexible PON is assigned to one of the plurality of modulation formats based on one or more parameters, such as configuration of the ONU and line conditions.

System and method for multimodulation in a passive optical network

A digital receiver based on one-dimensional hard demapping of an input symbol stream (FEC encoded) is configured to utilize LLRs created to have bit-specific magnitude values to improve the probability that the included decoder (such as an LDPC decoder) properly recovers each bit from the original stream. The digital receiver may be used with various types of data modulation schemes (e.g., PAM3, PAM4, DSQ8, etc.), with a specific set of LLR magnitudes created for each modulation scheme.

One-dimensional hard-input FEC receiver for digital communication

A method and apparatus is proposed for accurately evaluating the performance of optical transmitters under test conditions (such as high bit-rate modulation formats) that compromise the operability of standard test equipment used for this purpose. The proposed apparatus and method are similar to the elements associated with existing testing standards based on an optical eye diagram, with an important distinction that allows for accurate measurements of the transmitter's performance to be made. In particular, the sampling point for collecting eye diagram data samples in the inventive arrangement is shifted by half a period with respect to the conventional mid-eye sampling point, eliminating the need to include representative reference equalizer in the test equipment and providing an evaluation not influenced by the test equipment, resulting in a more accurate measurement of transmitter-related distortions.

Method and apparatus for evaluating transmitter performance capabilities in a passive optical network

Various example embodiments for supporting forward error correction (FEC) in a communication system are presented. Various example embodiments for supporting FEC in a communication system may include selection of a FEC setting (e.g., an amount of puncturing and/or shortening of a FEC code, a FEC code, or the like) for a communication channel from a transmitter to a receiver based on channel characteristic information of the communication channel from the transmitter to the receiver (e.g., transfer function information, channel loss information, noise characteristic information, error information (e.g., bit error rate, error modeling, or the like), or the like). Various example embodiments for supporting FEC in a communication system, based on selection of a FEC setting for a communication channel based on channel characteristic information of the communication channel, may be applied within various types of communication systems, including various types of wired and/or wireless communication systems.

Forward error correction

Various embodiments of the disclosed PON system enable approximate leveling of the optical-modulation amplitudes in a sequence of optical bursts received by a system's OLT from a plurality of ONUs. Some embodiments additionally enable approximate leveling of the average optical power, received at the OLT from different ONUs, in such a sequence. Some embodiments may rely on control messaging between the OLT and ONUs to perform one or both types of leveling. The disclosed leveling may advantageously provide an effective tool for optimizing upstream transmission for high-speed TDM-PONs.

Control of optical-modulation amplitude for burst-mode transmission

A customer location is identified that can be served by a base-station in a fixed wireless communication system. Embodiments of the invention generate a viewshed for an antenna of the base-station, compute an area of a rooftop at the customer location that is included in the generated viewshed, and identify the customer location as able to be served, or not, by the base-station, based on the area of the rooftop at the customer location that is included in the generated viewshed. Further, a parcel of land on which to install a fixed wireless communication base-station can be identified. Each candidate base-station parcel of land in a list ('candidate base-station locations') is evaluated and ranked. An evaluated candidate base-station location having a particular ranking is selected as the location on which to install the base-station.

Method and apparatus for qualifying customers and designing a fixed wireless network using mapping data

An upstream (US) optical line terminal (OLT) for a passive optical network having at least one downstream (DS) optical network unit (ONU). The OLT generates a trigger signal indicating a need to receive at least one US burst having a shortened codeword for a first forward error-correction (FEC) code. Based on the trigger signal, the OLT transmits a DS message instructing the ONU to transmit an US burst having a shortened codeword. The OLT receives and decodes the US burst having the shortened codeword using the first FEC code. During periods of high bit-error rate, the shortened codewords increase the ability of the OLT to decode the US bursts and keep communications from the ONU alive. The OLT can use the decoded US bursts to measure BER and, if appropriate, instruct the ONU to use a different FEC code.

Using shortened codewords in passive optical networks

An optical line terminal (OLT) operating within a multi-rate PON is configured to perform downstream timeslot scheduling among an associated number of ONUs so as to minimize the change in information rate from one scheduled ONU timeslot to the next. In this manner, the clock recovery component at each ONU is best able to follow the change in information rates, remaining locked on the system clock regardless of the specific implementation of the clock and data recovery (CDR) functionality at a given ONU. The OLT may schedule timeslot assignments that span a pair of adjacent parts (referred to as a two-part cycle), with the first part having timeslots assigned from the lowest information rate (e.g., NRZ) to the highest (e.g., PAM4) and the second part's timeslots assigned in the reverse order; that is, from the highest to the lowest information rate.

Method and apparatus for downstream timeslot scheduling in multi-rate passive optical networks

An apparatus, for use by an Optical Network Unit, performs receiving, from an Optical Line Terminal, a broadcast message including code set information indicating a first code set selected from a plurality of error correction code sets; determining whether the first code set is comprised in a group of code sets supported by the Optical Network Unit, wherein, the group of code sets includes at least one code set of the plurality of error correction code sets; and encoding an upstream transmission with the first code set, in case the first code set is included in the group of code sets.

Method and apparatus for ONU activation

Various example embodiments for supporting forward error correction (FEC) in a communication system are presented. Various example embodiments for supporting FEC in a communication system may include the selection of a FEC setting for a communication channel from a transmitter to a receiver, e.g., the selection of a FEC setting for a communication channel, the selection of a FEC setting for a data burst sent over a communication channel, the selection of a FEC setting for a portion of a data burst sent over a communication channel, switching between FEC settings for different portions of a data burst over a communication channel, or the like, as well as various combinations thereof.

Growing community of inventors

Edison, NJ, United States of America

Amitkumar Mahadevan