Nippon Telegraph and Telephone Corporation

Ntt Electronics Corporation

Mitsunori Fukutoku

Yutaka Miyamoto

Akira Masuda

Shuto Yamamoto

Kenya Suzuki

Ippei Shake

Hirotaka Ono

Shingo Kawai

Katsuhiro Shimano

Wataru Imajyuku

Tetsuo Takahashi

Toshio Watanabe

Yoshiaki Kisaka

Takayuki Mizuno

Norio Sato

Akira Hirano

Takafumi Tanaka

Yosuke Takeuchi

Keita Yamaguchi

Yuzo Ishii

Etsu Hashimoto

Yuichi Higuchi

Kazunori Seno

Naoki Ooba

Tomoyoshi Kataoka

Koichi Hadama

Hiroki Taniguchi

Kohki Shibahara

Akihiro Kadohata

Akira Isoda

Kazunori Senoo

Takeshi Kawai

Akio Sahara

Wataru Imaiyuku

An optically amplified repeater system includes optical transmission paths, a multi-channel optical amplifier, one or more Raman amplification pumping light sources, and a wavelength multiplexer. The multi-channel optical amplifier includes K simultaneous pumping light sources, N optical amplification media, and one or more optical couplers, and simultaneously amplifies, with the K simultaneous pumping light sources, light intensities of optical signals that pass through the N optical amplification media and propagate through the optical transmission paths. Light intensities of the wavelength band of the optical signals is Raman amplified by the Raman amplification pumping light. A light intensity of the Raman amplification pumping light output from the one or more Raman amplification pumping light sources is determined in accordance with characteristic differences between the optical signals passing through the optical transmission paths.

Optically amplified repeater system and optical amplifier

An optical node device includes one or more input-side wavelength selection switches, a plurality of output-side wavelength selection switches, and an amplification unit. The input-side wavelength selection switches include a plurality of output ports, separate input light in accordance with a wavelength, and output the separated light from the output port corresponding to an output destination of the separated light. The output-side wavelength selection switches include input ports each receiving the light output from each of the one or more input-side wavelength selection switches, multiplex the light received from the input ports, and output the light. The amplification unit amplifies the light output from each of the output ports of the input-side wavelength selection switches and outputs the amplified light to the output-side wavelength selection switch at the output destination corresponding to the output port.

Optical node device

A symbol-determining device according to an embodiment includes: a transmission line shortening unit that multiplies each symbol value of a symbol array that is part of an input signal by a tap gain of a linear digital filter and outputs a symbol array representing a sum of values acquired through the multiplication; a transmission line estimating unit that estimates a transfer function of a transmission line using an adaptive nonlinear digital filter on the basis of a symbol array representing a state of the transmission line; an addition comparison processing unit that calculates a minimum value of a distance function in a Viterbi algorithm on the basis of a metric that is calculated on the basis of the output of the transmission line shortening unit and the transfer function; and a path tracing-back determination unit that performs symbol determination by tracing back a trellis path in the Viterbi algorithm on the basis of the minimum value of the distance function.

Symbol-determining device and symbol determination method

An optical node device includes: a multicore optical amplification unit that amplifies collectively light transmitted along a multicore fiber; a separation unit that inputs the amplified light in each core to each of a plurality of input-side single-core fibers; an optical cross-connect switch that attenuates the light input from each of the plurality of input-side single-core fibers through an optical attenuator, separates the light in accordance with a wavelength, and outputs the separated light to an output-side single-core fiber of a plurality of output-side single-core fibers related to a respective output destination; a plurality of single-core optical amplification units that amplify the light transmitted along the corresponding output-side single-core fibers; and an output unit that outputs the light transmitted along each of the plurality of output-side single-core fibers to a multicore fiber. A control unit controls the optical attenuator and the single-core optical amplification unit based on input signal optical power and output optical signal power.

An encoding device includes an encoding unit, DA converters, light sources, intensity modulators, and wavelength multiplexers. The encoding unit adds (NM/2) to an encoded signal having a negative minimum value in a range of the encoded signal among encoded signals of N channels of (NM+1) values obtained by calculating an inner product of a Hadamard matrix of N rows and N columns and a matrix having elements of N intensity signals of (M+1) values. The DA converters of the channels convert the encoded signals of the channels from digital signals into electrical analog signals. The light sources output light of wavelengths for use in the channels. The light intensity modulators of the channels intensity-modulate the light output from the light sources with the encoded signals converted into the electrical analog signals by the DA converters. The wavelength multiplexer outputs a wavelength-multiplexed signal obtained by wavelength-multiplexing the light intensity-modulated by the light intensity modulators.

Encoding device and decoding device

To provide an optical signal processing device that can collect light from an input waveguide to form a beam array having a small diameter. The optical signal processing device includes input waveguidesto, an array waveguideand a slab waveguidethat is connected to a first archaving the single point C as a center and input waveguidestoand that is connected to a second archaving the single point C as a center and an array waveguide

Optical signal processing device with an array waveguide coupled to a slab waveguide with two arcs

A transmission system includes: an error correction encoding agent which converts an input data sequence into an encoded data sequence constituted of an error correction code and coded data; a data distribution agent which divides the encoded data sequence from the error correction encoding agent, in a predetermined processing unit and send them to a plurality of transmission routes; a data combining agent which combines signal sequences from the respective transmission routes and restores the encoded data sequence; an error correction decoding agent which applies error correction to and decodes the encoded data sequence from the data combining agent and outputs the input data sequence; and an agent for configuration in which a redundancy in the error correction encoding agent and a degree of splitting of the encoded data sequence in the data distribution agent are set.

Transmission system and transmission method

A wavelength selection switch system includes a wavelength selection switch including an input port and an output port, a nonvolatile memory in which configuration information for controlling an operation of the wavelength selection switch is stored, a high-speed memory in which reading and writing can be performed at a higher speed than in the nonvolatile memory and that stores a copy of the configuration information stored in the nonvolatile memory, and a control unit that controls an operation of the wavelength selection switch based on the configuration information read from the high-speed memory, wherein the control unit periodically reads the configuration information stored in the nonvolatile memory and writes a copy of the read configuration information to the high-speed memory.

Wavelength selection switch system and method for controlling wavelength selection switch

A packet transfer method in a network apparatus that transfers packets is disclosed. In the packet transfer method, a sending side apparatus generates two copies of a send packet, provides a sequence number identifying the same sending sequence to each of the copied packets, provides an identifier corresponding to a send/receive pair to each of the copied packets to send the packets, and a receiving side apparatus receives each of the packets with two receiving units; recognizes the identifiers each corresponding to a send/receive pair; identifies packets having the same information and the sequence based on the sequence number when the identifiers are the same; selects one of the packets of the same sequence so as to send the packet downstream, and discards another packet, wherein, when only one of the packets of the same sequence arrives, the arriving packet is sent downstream.

Packet transmission method and packet transmission device

Growing community of inventors

Yokosuka, Japan

Mitsunori Fukutoku