Nippon Telegraph and Telephone Corporation

Junichi Kani

Masamichi Fujiwara

Hiroo Suzuki

Takuya Kanai

Mitsuhiro Teshima

Kenichi Suzuki

Katsumi Iwatsuki

Shin Kaneko

Katsuhiro Araya

Kazuaki Honda

Noriko Iiyama

Sang-Yuep Kim

Takahiro Suzuki

Ryo Igarashi

Hiroji Masuda

Kota Asaka

Noboru Takachio

Keita Nishimoto

Koji Akimoto

Jun Terada

Manabu Yoshino

Takashi Yamada

Hirotaka Nakamura

Hirotaka Ujikawa

Takumi Harada

Ryogo Kubo

Yumiko Senoo

Yukio Toyoshima

Yasunari Tanaka

Yukihiro Fujimoto

Mitsumasa Okada

Ukyo Yamaguchi

Hidetaka Onishi

One aspect of the present invention is a optical main signal processing node apparatus including: an input port for inputting an optical multiplexed with signals pertaining to a plurality of services from an optical transmission path; an output port for outputting an optical signal multiplexed with signals pertaining to a plurality of services to an optical transmission path; a optical main signal processer configured to perform optical main signal processing on an optical signal input from the input port; and a path switch configured to switch a path of the optical signal input from the input port to one of a first path for guiding the optical signal to the output port and a second path for guiding the optical signal to the optical main signal processer.

Optical main signal processing node apparatus and control method of optical main signal processing node apparatus

An optical signal processing apparatus includes a removal unit and a superimposition unit. The removal unit receives, from a first optical transmission path, an optical signal converted from an electrical signal, in which a first signal and a second signal having different frequencies from each other have been superimposed, and removes the second signal from the optical signal which has been input. The superimposition unit superimposes a third signal having a frequency different from a frequency of the first signal on the optical signal in which the second signal has been removed by the removal unit, and outputs the optical signal in which the third signal has been superimposed to a second optical transmission path.

Optical signal processing apparatus and optical signal processing method

A transmitter management device includes: a reception unit that receives a virtual switch configuration request from an upper management system; a determination unit that determines a plurality of paths including transfer processing by different optical transmitters on the basis of the configuration request received by the reception unit; and a setting unit that performs a setting for a plurality of the optical transmitters in such a way that a virtual switch that executes transfer processing on the basis of the paths determined by the determination unit is configured for each one of a plurality of the paths.

Transmission device management device, transmission device management system, transmission device management method and program

The optical communication system includes the optical distribution device () provided between the wavelength routing device () and the optical multiplexing/demultiplexing device (). The wavelength routing device outputs the optical signal input from the port on the wavelength variable subscriber device side to the port uniquely determined by a combination of the wavelength of the optical signal and the port to which the optical signal is inputted. The wavelength variable subscriber device can execute the first protection for switching the wavelength of the optical signal to be transmitted and received to the spare wavelength different from the operating wavelength when the wavelength variable subscriber device and the wavelength variable communication device () are disconnected. Then, the optical distribution device can execute the second protection for switching the optical fiber transmission path () to be used when the wavelength variable subscriber device and the wavelength variable communication device are disconnected.

Optical communication system and protection method for optical communication system

Provided is an optical receiver including: a heterodyne detection unit that converts, by heterodyne detection, a subcarrier multiplexed signal in which a plurality of optical signals transmitted from a plurality of optical transmitters are multiplexed, into an electrical signal in an intermediate frequency band; a filter unit that removes a carrier component from the electrical signal in the intermediate frequency band, generated by the conversion, to extract a subcarrier component; an analog-digital conversion unit that performs analog-digital conversion on a signal having the subcarrier component, extracted by the filter unit; and a digital signal processing unit that performs digital signal processing for each subcarrier on a digital signal generated by the analog-digital conversion performed by the analog-digital conversion unit.

Optical receiver and optical receiving method

An aspect of the present disclosure is a transmission system including a modulated wave generation unit that generates an intermediate wave, which is a coherent wave in which a frequency component of either of two signals overlays a frequency spectrum, the two signals being a main signal indicating transmitted information to be transmitted and a control signal indicating management information, which is information on communication between a transmission source of the transmitted information and a communication destination of the transmission source, and a modulation unit that modulates the intermediate wave with a signal in which a frequency component does not overlay the frequency spectrum of the coherent wave generated by the modulated wave generation unit out of the two signals that are the main signal and the control signal. In the transmission system, a frequency band of the main signal and a frequency band of the control signal do not overlap each other.

Transmission system, transmission method, and communication system

A communication device includes: a MAC unit that processes a main signal including a payload, and determines a communication timing of the main signal; a communication unit that performs, based on the communication timing, at least one of transmission processing for E/O converting the main signal acquired from the MAC unit, and transmitting the main signal to a communication counterpart device, and reception processing for O/E converting the main signal received from the communication counterpart device; a main signal transmission line through which the main signal is transmitted between the MAC unit and the communication unit; and a control information transmission line that is provided separately from the main signal transmission line, and through which communication timing data that is data indicating the communication timing is transmitted from the MAC unit to the communication unit.

Communication apparatus and communication method

A communication system includes a subscriber network unit and a communication device provided in an accommodating station. The subscriber network unit includes an acquisition unit that acquires uplink data from one or more lower-layer devices. The communication device includes: a data processing unit that acquires the uplink data from the subscriber network unit using a band of uplink communication and executes data processing on the acquired uplink data; a policy determination unit that determines a policy of band allocation of the uplink communication on the basis of the result of the data processing; and an allocation control unit that allocates the band of the uplink communication to the subscriber network unit on the basis of the policy.

Communication system, communication apparatus and bandwidth allocation method

A data process device includes a data input unit and a processor. The processor includes a division unit, a first storage unit and a second storage unit which have a plurality of storage areas, a write unit, a calculation unit, and a control unit. The division unit divides a data series input by the data input unit to generate a plurality of divided data. The write unit writes the divided data to the first storage unit according to writing order to the storage areas in the first storage unit. The calculation unit performs calculation processing on the divided data written to the first storage unit, and writes calculated data obtained by the calculation processing to the second storage unit according to writing order to the storage areas in the second storage unit. The control unit controls processing of the write unit and processing of the calculation unit, which are divided into different processing lines, to be executed in parallel by pipeline processing.

Data processing apparatus, data processing method and program

An optical reception device including: a local light transmission unit configured to generate a plurality of local lights having different wavelengths, select a local light having a wavelength that is close to the wavelength of a received optical signal from among the plurality of generated local lights having different wavelengths, and transmit the selected local light to a coherent receiver; a demultiplexing unit configured to demultiplex a received optical signal and transmit the demultiplexed optical signal to the coherent receiver via a first path; and a wavelength detection unit configured to input the optical signal demultiplexed by the demultiplexing unit via a second path, split the input optical signal into different paths according to wavelengths by using a wavelength multiplexer/demultiplexer, and output, to the local light transmission unit, a control signal for causing the local light transmission unit to output a local light having a frequency that corresponds to a path in which the optical signal is included.

Optical receiving apparatus, optical transmission system, optical transmission method and computer program

Provided is a communication device including: a transmission timing calculation unit configured to calculate a transmission timing of a first frame using the number of transmitted bits from a predetermined timing to transmission of the first frame and a throughput; a transmission unit configured to transmit the first frame to an external device at the transmission timing; a reception unit configured to receive a second frame from the external device in response to the first frame; a reception timing calculation unit configured to calculate a reception timing of the second frame using the number of received bits from a predetermined timing to reception of the second frame by the reception unit and a throughput; and a round trip time calculation unit configured to calculate a round trip time using a processing time required by the external device from the reception of the first frame to the transmission of the second frame, the transmission timing, and the reception timing.

Communication apparatus and ranging method

An optical reception device including: a wavelength selection unit configured to split an optical signal amplified by an optical amplifier into different paths according to wavelengths by using a wavelength multiplexer/demultiplexer, and control a passage state of a passage target optical switch through which the optical signal is to be passed, out of a plurality of optical switches provided on the respective paths, to select an optical signal of a path where the optical signal entered and output the optical signal to a receiver; and a wavelength detection unit configured to detect the wavelength of an optical signal by using each of a plurality of optical detectors, determine the passage target optical switch based on a detection result, and output, to the determined passage target optical switch, a control signal for controlling the passage target optical switch so as to enter the passage state, the optical detectors being respectively provided on different paths that are different from the paths on which the plurality of optical switches are provided and that respectively correspond to wavelengths into which the optical signal is split by a wavelength multiplexer/demultiplexer.

A communication apparatus includes: a memory that stores, first data on firmware before update, second data on firmware after the update, and a table in which the first data or the second data is associated with an address where the first data or the second data is positioned; and a processor that executes processing based on the first data or the second data positioned at the address defined in the table.

Communication device and information processing method

An ADC () in an optical receiver () generates a sample signal composed of time series samples by oversampling a received signal that is an electrical signal converted from an optical signal by a light receiving unit (). A symbol timing detection unit () of a DSP unit () detects a symbol timing in the sample signal. When it is determined that a symbol timing is appearing at a longer interval than a predetermined interval based on this detection result, a symbol timing adjusting unit () skips one or more samples included in the sample signal to read out samples at the predetermined interval, while when it is determined that the symbol timing is appearing at a shorter interval than the predetermined interval, the symbol timing adjusting unit inserts the same samples as one or more samples included in the sample signal immediately after the one or more samples to read out the samples at the predetermined interval.

Signal processing apparatus and optical receiver

A reception apparatus includes a detection unit that detects occurrence of a phase slip in phase estimation values of time-series received symbol data, and determines an inclination of the phase slip, a delay processing unit that generates first received signal data obtained by delaying received signal data obtained from the time-series received symbol data by one symbol time interval, a phase shift unit that generates second received signal data by performing phase shift according to the inclination, only in a period in which one symbol time interval elapses, on only the received signal data of a symbol time at which the occurrence of the phase slip is detected among pieces of the received signal data, and a remainder processing unit that derives a remainder of a difference between the second received signal data and the first received signal data.

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Narashino, Japan

Junichi Kani