公开(公告)号：US20220173813A1

公开(公告)日：2022-06-02

申请号：US17437925

申请日：2020-03-06

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsuko KAWAKITA ,  Kazutaka HARA ,  Yasutaka KIMURA ,  Kenji HORIKAWA ,  Hiroyuki FURUKAWA

IPC: H04B10/572 ,  G02B6/287 ,  H04B10/272 ,  H04B10/50 ,  H04J14/02

Abstract: An object is to provide an optical communication system and an optical communication method that are capable of, when assigning wavelengths on a per-service basis and providing services on a per-area basis, preventing degradation of signal quality due to linear crosstalk and preventing an increase in cost and size. An optical communication system according to the present invention includes an optical splitter 300 connecting N first ports and M second ports by a combination of 2×2 fiber optical splitters, N and M each being an integer of two or more, where wavelengths of optical signals to be received are limited for each group of optical receivers 106, by using a correlation between a fused extension length of at least one 2×2 fiber optical splitter directly connected to the first port, among the 2×2 fiber optical splitters, and wavelength output characteristics of the second port of the optical splitter 300.

公开(公告)号：US20220360534A1

公开(公告)日：2022-11-10

申请号：US17624464

申请日：2019-07-04

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Tatsuya FUKUI ,  Katsuya MINAMI ,  Yuki SAKAUE ,  Hiroyuki FURUKAWA

IPC: H04L47/215 ,  H04L47/56 ,  H04L47/52 ,  H04L47/50

Abstract: An object is to provide a communication apparatus, a communication method, and a program capable of avoiding an increase in network load when input traffic continues to be large and a communication delay when input traffic is very small. A communication apparatus according to the present invention prepares three token buckets and can transfer, discard, or hold a packet in accordance with the amount of tokens in each token bucket. This enables the communication apparatus to operate so as not to exceed a set maximum bandwidth when large traffic is received for the delay guarantee shaping. Further, When the maximum bandwidth is exceeded, the communication apparatus can select whether to discard a packet to prioritize a delay guarantee or to hold a packet to prioritize no loss of packets. Furthermore, the communication apparatus can immediately transmit a packet without increasing a communication delay when input traffic is very small.

公开(公告)号：US20220166532A1

公开(公告)日：2022-05-26

申请号：US17440410

申请日：2020-03-06

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsuko KAWAKITA ,  Kazutaka HARA ,  Yasutaka KIMURA ,  Kenji HORIKAWA ,  Hiroyuki FURUKAWA

IPC: H04J14/02 ,  G02B6/287 ,  H04B10/272

Abstract: An object is to provide an optical communication system capable of controlling the output ratio by port and by wavelength for incident light of different wavelengths, a method of determining the split ratio of an uneven-split optical splitter for controlling the output ratio by port and by wavelength, and a transmission range determination method for the optical communication system. The split ratio determination method for an uneven-split optical splitter according to the present invention uses the melt-draw distance to adjust the split ratio of each fiber-optic splitter included in the uneven-split optical splitter such that the light output from the farthest ONUs among each of the ports connected under the ports B to M of the uneven-split optical splitter arrives with the minimum reception sensitivity at OLT receivers in a PON system.

公开(公告)号：US20210194589A1

公开(公告)日：2021-06-24

申请号：US17271222

申请日：2019-08-21

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Atsuko KAWAKITA ,  Kazutaka HARA ,  Hiroyuki FURUKAWA ,  Yasutaka KIMURA ,  Kenji HORIKAWA

IPC: H04B10/272 ,  H04L12/44 ,  G02B6/27

Abstract: To provide an optical communication system and an optical communication method able to achieve a high reliable access network capable of long haul distance transmission considering the optical energy efficiency even if the user distribution is biased. An uneven branch optical splitter included in an optical communication system according to the present invention can output the optical intensities different for each output port by adjusting the branching configuration and the branching ratio. For example, a reach transmission distance of the farmost user can be extended or the number of connectible users can be increased by adjusting the branching configuration of the uneven branch optical splitter or the branching ratios such that the near minimum reception sensitivity is given for the ONU installed near the telecommunications carrier.