公开(公告)号：US20230318730A1

公开(公告)日：2023-10-05

申请号：US18015680

申请日：2020-07-15

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takamitsu TOCHINO ,  Hirotaka UJIKAWA ,  Hirotaka NAKAMURA

IPC: H04J14/02

CPC classification number: H04J14/0227 ,  H04J14/0201

Abstract: A communication device that is connected to a wavelength-multiplexed optical ring network and conducts communication by performing time-division multiplexing on an optical signal for each wavelength includes: a communication unit that transmits a requested transmission amount for requesting a transmission band to a master communication device, and receives an allowed transmission amount for allocating a transmission band from the master communication device; and a control unit that estimates a band utilization rate of each wavelength on the basis of the requested transmission amount and the allowed transmission amount, and allocates data to the respective wavelengths so as to equalize the band utilization rates among the wavelengths. Thus, it is possible to equalize band utilization rates among wavelengths, and enhance communication efficiency of the entire system.

公开(公告)号：US20230246717A1

公开(公告)日：2023-08-03

申请号：US18011280

申请日：2020-06-24

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hirofumi YAMAMOTO ,  Hirotaka NAKAMURA

IPC: H04B10/80

CPC classification number: H04B10/806

Abstract: An optical communication system 1 includes an OLT 100 and an ONU 200. The ONU 200 includes a local power supply reception unit 202 capable of receiving power from an external power supply 300, a station-side power supply reception unit 204 connected to a station-side power supply 110 controlled by the OLT 100, via a power supply cable 120, and a power feeding switching unit 205 capable of selectively switching a state of the ONU 200 between a first state in which power feeding is performed by the local power supply reception unit 202 and a second state in which power feeding is performed by the station-side power supply reception unit 204. Upon an amount of power fed by the local power supply reception unit 202 falling below a prescribed amount in the first state, the ONU 200 transmits a power transmission request signal to the OLT 100 and switches from the first state from the second state via the power feeding switching unit 205. Upon reception of the power transmission request signal, the OLT 100 makes the station-side power supply 110 perform power transmission to a second power reception unit of the ONU 200.

公开(公告)号：US20230188240A1

公开(公告)日：2023-06-15

申请号：US17923895

申请日：2020-05-18

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takamitsu TOCHINO ,  Hirotaka UJIKAWA ,  Hirotaka NAKAMURA

IPC: H04J3/08 ,  H04B10/275

CPC classification number: H04J3/085 ,  H04B10/275

Abstract: There is provided a communication method used in a communication system in which a plurality of communication apparatuses is connected by an optical ring network, the communication method including: setting one of the plurality of communication apparatuses as a master communication apparatus and the other communication apparatuses as slave communication apparatuses, causing the master communication apparatus to transmit an optical signal at transmission timing determined in the master communication apparatus; causing the master communication apparatus to transmit an assignment signal for assigning, to the slave communication apparatuses, transmission timing at which an optical signal on at least one wavelength is time-division multiplexed and transmitted; and causing the slave communication apparatuses to transmit an optical signal to the optical ring network based on transmission timing assigned by the assignment signal received from the master communication apparatus. As a result, the number of wavelengths needed for communication is reduced, and even when communication paths increases due to an increase in the number of optical transmission apparatuses, there is no need to increase the number of wavelengths, thereby solving the problem in economic efficiency.

公开(公告)号：US20210083778A1

公开(公告)日：2021-03-18

申请号：US16970284

申请日：2019-02-21

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Kazuaki HONDA ,  Hirotaka NAKAMURA ,  Jun TERADA

IPC: H04B10/572 ,  H04B10/272 ,  H04B10/079 ,  H04B10/50

Abstract: An OLT (2) includes one or more optical receivers (22) configured to receive optical signals of respective different wavelengths obtained by an AWG filter (4) demultiplexing a wavelength-multiplexed signal addressed to the terminal itself, and a supervisory controller (23) configured to transmit, to an ONU (3), a wavelength adjustment instruction to transit a wavelength to be used by an optical transmitter (32) for transmission of an optical signal, to set a difference between an optical received power of an optical signal received by any of the optical receivers (22) and a reference value of the optical received power within a threshold, the ONU (3) being a transmission source of the optical signal.

公开(公告)号：US20230275682A1

公开(公告)日：2023-08-31

申请号：US18015435

申请日：2020-07-15

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takamitsu TOCHINO ,  Hirotaka UJIKAWA ,  Hirotaka NAKAMURA

IPC: H04J14/08

CPC classification number: H04J14/08

Abstract: A communication device includes: a communication unit that is connected to an optical ring network, conducts optical signal communication by time-division multiplexing, and receives a control signal for controlling an optical signal transmission timing from a master communication device; and a determination unit that determines the master communication device not to be operating properly and causes the subject communication device to operate as a new master communication device, in a case where the control signal is not received in a predetermined period. Thus, even in a case where the master device cannot operate properly, a slave device operates as the master device, so that the system operation can be continued.

公开(公告)号：US20220417914A1

公开(公告)日：2022-12-29

申请号：US17269211

申请日：2019-08-16

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hiroyuki UZAWA ,  Hirotaka UJIKAWA ,  Hirotaka NAKAMURA

IPC: H04W72/04 ,  H04W28/20 ,  H04W72/12

Abstract: A bandwidth allocation apparatus includes an acquisition unit acquiring scheduling information related to transmission of uplink data from a first subscriber line termination apparatus corresponding to a subscriber line termination apparatus needing to transfer uplink data with low latency, a requested amount reception unit receiving, from second subscriber line termination apparatus corresponding to a subscriber line termination apparatus not needing to transfer uplink data with low latency, information representing a requested amount related to transmission of uplink data from the second subscriber line termination apparatus, in a requested amount reception cycle corresponding to a cycle equal to or longer than a predetermined maximum round-trip time, and an allocation unit allocating, in an allocation amount determination cycle shorter than the requested amount reception cycle, a bandwidth to the uplink data from the first subscriber line termination apparatus on a basis of the scheduling information, and allocating, in the allocation amount determination cycle, a bandwidth to the uplink data from the second subscriber line termination apparatus on a basis of the information representing the requested amount.

公开(公告)号：US20220123838A1

公开(公告)日：2022-04-21

申请号：US17431668

申请日：2020-02-14

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Rintaro HARADA ,  Hiroyuki UZAWA ,  Hirotaka NAKAMURA ,  Jun TERADA

IPC: H04B10/27

Abstract: A transfer device installed between a host device and a plurality of OLTs in a communication system to which a network with a PON configuration including the plurality of OLTs between the host device and a subordinate device is applied, the transfer device including a frame information acquisition unit configured to monitor downstream frames input from the host device and calculate a statistical value of the downstream frames per a predetermined fixed cycle, a frame storage unit including a plurality of queues each configured to store downstream frames to be transferred to the plurality of OLTs, the frame storage unit configured to store the downstream frames input from the host device, a frame sorting unit configured to input the downstream frames to the plurality of queues in the frame storage unit, and a distribution control determination unit configured to determine the number of frames to be sequentially input by the frame sort unit to the plurality of queues based on the statistical value.

公开(公告)号：US20210112016A1

公开(公告)日：2021-04-15

申请号：US17057034

申请日：2019-05-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Rintaro HARADA ,  Hiroyuki UZAWA ,  Hirotaka NAKAMURA ,  Daisuke HISANO ,  Hirotaka UJIKAWA ,  Jun TERADA

IPC: H04L12/865

Abstract: A transfer apparatus include a distribution unit, a storage unit, and a transfer unit, in which the distribution unit is configured to identify a plurality of networks to which frames belong, distribute the frames for each of the networks based on an identification result, and store the distributed frames in the storage unit, the storage unit is configured to store information of a time at which a frame of the frames is stored in the storage unit and the frame in association with each other, and the transfer unit is configured to detect a period of time for which the frame stays in the storage unit, detect a remaining period to send which is a remaining time of a time for which the frame is permitted to stay in the storage unit, for each of the frames, based on a difference between the time for which the frame stays in the storage unit and the delay upper limit value, and output the frame to a predetermined apparatus based on the remaining period to send.

公开(公告)号：US20160127045A1

公开(公告)日：2016-05-05

申请号：US14896067

申请日：2014-06-24

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Kota ASAKA ,  Katsuhisa TAGUCHI ,  Hirotaka NAKAMURA

IPC: H04B10/516 ,  H04B10/564

CPC classification number: H04B10/516 ,  H04B10/505 ,  H04B10/564

Abstract: A bias point of an external modulator is set to different values according to on and off of a burst control signal and an optical source is driven continuously in a burst optical signal transmission device. The burst optical signal transmission device avoid generation of transient fluctuation of a wavelength and a light amount at the time of burst signal rising.

Abstract translation: 外部调制器的偏置点根据突发控制信号的导通和关断设置为不同的值，并且在突发光信号传输装置中连续驱动光源。 突发光信号传输装置避免在突发信号上升时产生波长的瞬态波动和光量。

公开(公告)号：US20230261744A1

公开(公告)日：2023-08-17

申请号：US18015403

申请日：2020-07-15

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takamitsu TOCHINO ,  Hirotaka UJIKAWA ,  Hirotaka NAKAMURA

IPC: H04B10/079 ,  H04B10/077

CPC classification number: H04B10/0791 ,  H04B10/0771

Abstract: A communication device is connected to a wavelength-multiplexed optical ring network, and performs communication by performing time-division multiplexing on optical signals at each wavelength. In a case where a control signal transmitted from the master communication device is not received in a predetermined period, the communication device instructs a scheduler unit to suspend transmission of data at a failure wavelength that is the wavelength at which the host communication device has been determined not to be operating properly, also instructs the scheduler unit to transmit the data stored in the buffer of the failure wavelength at another wavelength, and suspends allocation of new data to the buffer of the failure wavelength. Thus, the delay in transmission of data at the failure wavelength can be shortened.