公开(公告)号：US20250097612A1

公开(公告)日：2025-03-20

申请号：US18469515

申请日：2023-09-18

Applicant: Nokia Solutions and Networks Oy

Inventor： Kovendhan Vijayan ,  Robert Borkowski ,  Vincent Houtsma ,  Doutje Van Veen ,  Amitkumar Mahadevan

IPC: H04Q11/00 ,  G02B6/293 ,  H04B10/25

Abstract: Various example embodiments for providing a passive optical network (PON), supporting communications between an optical line terminal (OLT) and a set of optical network units (ONUs) of a PON, are presented. The PON may be enabled based on use of an optical frequency comb (OFC), generated at the OLT and reconstructed at the ONUs for locking the OFC at the ONUs to the OFC at the OLT. The OFC may include a set of optical frequency lines used as seed lines for reconstruction of the OFC at the ONUs (e.g., the pair of OFC lines at the center of the OFC which may be used to regenerate locked OFCs at the ONUs), a set of optical frequency lines used to support downstream communications from the OLT to the ONUs, and a set of optical frequency lines used to support upstream communications from the ONUs to the OLT.

公开(公告)号：US12244348B2

公开(公告)日：2025-03-04

申请号：US17714959

申请日：2022-04-06

Applicant: NOKIA SOLUTIONS AND NETWORKS OY

Inventor： Doutje Van Veen ,  Amitkumar Mahadevan ,  Vincent Houtsma

IPC: H04B10/54 ,  H04L27/26

Abstract: 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.

公开(公告)号：US12126948B2

公开(公告)日：2024-10-22

申请号：US17746658

申请日：2022-05-17

Applicant: Nokia Solutions and Networks Oy

Inventor： Doutje Van Veen ,  Amitkumar Mahadevan ,  Vincent Houtsma

IPC: H04Q11/00 ,  H04B10/073 ,  H04B10/2557

CPC classification number: H04Q11/0067 ,  H04B10/0731 ,  H04B10/2557 ,  H04Q2011/0083

Abstract: 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.

公开(公告)号：US20240323065A1

公开(公告)日：2024-09-26

申请号：US18125225

申请日：2023-03-23

Applicant: Nokia Solutions and Networks Oy

Inventor： Doutje Van Veen ,  Vincent Houtsma

IPC: H04L25/03 ,  H04B10/2575

CPC classification number: H04L25/03878 ,  H04B10/25759 ,  H04L25/03006 ,  H04L2025/03815

Abstract: A phased approach to training of an upstream burst mode receiver equalizer is disclosed that proceeds incrementally through modulation schemes requiring increasing levels of equalization in a manner where the equalizer maintains the capability to accurately recover data transmitted during each training phase. The phased approach includes an initial training phase (one or more upstream bursts) using a simple modulation format, one or more intermediate phases of different modulation schemes, and a final training phase using the PON-defined (high) line rate upstream modulation format. Equalizer settings generated during the initial phase are used as a starting point for the equalization process in the next training phase, and so on, until the equalizer training reaches the final phase where the ONU uses the PON-defined upstream data rate and the burst mode equalizer is updated accordingly.

公开(公告)号：US20220123863A1

公开(公告)日：2022-04-21

申请号：US17470293

申请日：2021-09-09

Applicant: Nokia Solutions and Networks Oy

Inventor： Yannick Lefevre ,  Adriaan de Lind van Wijngaarden ,  Jochen Maes ,  Vincent Houtsma ,  Doutje Van Veen ,  Amitkumar Mahadevan ,  Michaël Fivez

IPC: H04L1/00 ,  H03M13/00 ,  H04B10/516 ,  H04B10/60

Abstract: 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.

公开(公告)号：US20190253152A1

公开(公告)日：2019-08-15

申请号：US15896783

申请日：2018-02-14

Applicant: Nokia Solutions and Networks OY

Inventor： Vincent Houtsma ,  Doutje van Veen

IPC: H04B10/61 ,  H04B10/54 ,  H04L7/00

CPC classification number: H04B10/616 ,  H04B10/5167 ,  H04B10/541 ,  H04B10/612 ,  H04B10/69 ,  H04J14/0282 ,  H04L7/0075

Abstract: A PON having an OLT configured to send downlink transmissions to ONUs using amplitude modulation and two symbol rates. An example ONU includes a clock-recovery circuit capable of continuous clock extraction from the received variable-rate modulated optical signal. The continuous clock extraction can be achieved, e.g., by (i) configuring the photodetector to convert the higher-rate portions of the received optical signal into transformed electrical waveforms while converting the lower-rate portions thereof into similar electrical waveforms and (ii) configuring the clock-recovery circuit to phase-align the clock signal with signal transitions in the resulting sequence of transformed and similar electrical waveforms. An ONU configured to operate in this manner can advantageously stay locked to the received data signal during transmissions at both symbol rates, without the need to reacquire the clock signal at each rate change and/or at the beginning of each packet intended for the host ONU.

公开(公告)号：US20190238235A1

公开(公告)日：2019-08-01

申请号：US15885385

申请日：2018-01-31

Applicant: Nokia Solutions and Networks OY

Inventor： Vincent Houtsma ,  Doutje van Veen

IPC: H04B10/64 ,  H04B10/079 ,  H04B10/572 ,  H04J14/08

CPC classification number: H04B10/64 ,  H04B10/0795 ,  H04B10/572 ,  H04J14/08

Abstract: A passive optical network having an optical-signal monitor configured to monitor carrier-wavelength drifts during optical bursts transmitted between the optical line terminal and optical network units thereof. In an example embodiment, the optical-signal monitor uses heterodyne beating between two differently delayed portions of an optical burst to generate an estimate of the carrier-wavelength drift during that optical burst. The passive optical network may also include an electronic controller configured to use the estimates generated by the optical-signal monitor to make configuration changes at the optical network units and/or implement other control measures directed at reducing to an acceptable level the amounts of carrier-wavelength drift during the optical bursts and/or mitigating some adverse effects thereof.