Nippon Telegraph and Telephone Corporation

Ntt Corporation

Ntt Electronics Corporation

Hideki Nishizawa

Seiji Okamoto

Tetsuro Inui

Seiki Kuwabara

Shuto Yamamoto

Toru Mano

Akira Hirano

Kenya Suzuki

Takuya Oda

Takafumi Tanaka

Fumikazu Inuzuka

Osamu Moriwaki

Keita Yamaguchi

Shunichi Soma

Junki Ichikawa

Tomoya Hibi

Kiwami Inoue

Etsushi Yamazaki

Kei Kitamura

Shokei Kobayashi

Kazuhito Takei

Osamu Ishida

Yukio Tsukishima

Kenji Shimizu

Wataru Kawakami

Yasuhiro Suzuki

Masanori Nakamura

Masahito Tomizawa

Kengo Horikoshi

Takeru Inoue

Kazuya Anazawa

Hirokazu Takahashi

Atsushi Taniguchi

A connection optimization device that optimizes connections between a plurality of FXC switches for switching connections of optical fibers includes a optimization unit for receiving, as inputs, a number k of FXC switches, a number n of sending/receiving ports, and a connection probability matrix C of the sending/receiving ports and swapping rows and columns of the connection probability matrix C so as to maximize an expected value D in which a connection probability using a short path connecting between the sending/receiving ports connected in the same FXC switch becomes the largest, and a swapping port information output unit for outputting difference information between the connection probability matrix C and the optimization matrix C* in which the rows and the columns are swapped by the optimization unit.

Connection optimization device, connection optimization method, and program

A transmission device () includes a modulation unit () that modulates photons with a predetermined data pattern, a synchronization signal generation unit () that generates a frame synchronization signal of a random number data pattern, an identification signal generation unit () that divides the frame into a plurality of subframes and generate a subframe identification signal indicating a subframe, and a transmission unit () that transmits the photons modulated by the modulation unit (), the frame synchronization signal, and the subframe identification signal. A reception device () includes a reception unit () that receives the photons, the frame synchronization signal, and the subframe identification signal transmitted from the transmission unit (), a decoding unit () that detects and decodes a data pattern from the photons, a time measurement unit () that measures an elapsed time from the subframe identification signal until a photon is detected in each subframe, and a detection time calculation unit () that calculates a photon detection time from the frame synchronization signal to photon detection in one frame, based on the elapsed time.

Quantum key distribution system, quantum key distribution method and quantum key distribution program

An intermediate deviceA includes a transfer unitthat transfers a request including data to be transmitted from a localto a remote, and a generation unitthat generates a pseudo-response to the request and returns the pseudo-response to the local. The intermediate deviceB includes a discard unitthat discards a response to the request from the remote. An intermediate deviceB includes a generation unitthat generates a pseudo-request based on an initial request for requesting data transmission from the localto the remoteand transmits the pseudo-request to the remote, and a transfer unitthat transfers a response including data to be transmitted from the remoteto the local. The intermediate deviceA includes the discard unitthat discards a subsequent request from the local

Intermediate apparatus, communication method, and program

An optical transmission system including an optical transmission device and an optical reception device that receives, via an optical transmission line, a signal transmitted from the optical transmission device, the optical transmission system including a transmission-mode selection unit that selects transmission mode information in descending order of priority out of transmission mode information, which is combinations of a plurality of parameters concerning transmission performance, the transmission mode information being a plurality of kinds of the transmission mode information common to the transmission performance of the optical transmission device and the optical reception device, a signal transmission unit that transmits, to the optical reception device, a signal modulated based on the selected transmission mode information, and a signal reception unit that receives the signal and modulates the received signal based on the transmission mode information selected by the transmission-mode selection unit.

Optical transmission system and transmission mode selecting method

A communication system includes a plurality of computing machinesandconnected to an optical network, in which the optical network includes a main signal communication pathand a control communication path. Each of the computing machinesandincludes a control unitthat sets a remote direct memory access (RDMA) communication path, and a communication unitthat transmits a setting request including setting information of the RDMA communication path set by the control unitand setting information for setting the main signal communication pathto a computing machine of an access destination via the control communication path; and a main signal transmitting/receiving unitthat establishes the main signal communication pathbased on the setting information of the main signal communication path

Communication system, computing machine, communication method and program

This communication system comprises a plurality of computersthat each comprise: an optical transport path control unitthat adjusts the number of optical transport paths between the computer itself and a connection target computer and that sets the adjusted number of optical transport paths; a remote direct memory access (RDMA) communication unitthat, in accordance with the number of optical transport pathsannounced from the optical transport path control unit, chunks data that is to be transferred to the connection target computer; and an RDMA control unitthat sets RDMA communication paths the number of which is the same as the number of the optical transport pathspursuant to an instruction from the RDMA communication unit

The communication apparatus includes: a processing device that processes communication data to be transmitted to and received from a partner apparatus; a transmission unit that transmits the communication data to the partner apparatus; an internal state measurement unit that measures a state related to transmission of the communication data between the processing device and the transmission unit and a determination unit that determines a communication mode in communication with the partner apparatus from the state. The transmission unit transmits the communication data to the partner apparatus in the determined communication mode.

Communication apparatus, relay apparatus, communication system, communication method, and program

A high-performance optical and electronic integrated switch capable of effectively extending the transmission distance includes a network processor that controls the functions of the packet switch, a plurality of optical transceivers provided near the processor and having a photoelectric conversion function, and an optical relay switch. A plurality of optical waveguides are connected to the input and output sides of the optical relay switch. Each optical transceiver has a regeneration function that performs optical-electrical conversion on inputted optical signals, then turns back the converted signals, and performs signal conversion on them, and its input side is connected with a routing optical waveguide included in the optical waveguides on the output side of the switch and its output side is connected with a routing optical waveguide included in the optical waveguides on the input side of the switch. The optical waveguides include ones for connecting to an external communication counterpart.

Optical and electronic integrated switch

A virtual environment optical communication network is generated by setting configuration parameters of physical packages of a real environment optical communication network in package emulators that a computer program has virtually constructed to implement the physical packages, the real environment optical communication network being constructed by a plurality of node devices in which the physical packages are mounted, pieces of configuration data are generated based on pieces of resource data indicating resources required for optical paths detected based on acquired configuration parameters and a requested transmission mode, optical paths are set in the virtual environment optical communication network based on the generated pieces of configuration data, and optical paths are set in the real environment optical communication network based on the pieces of configuration data that have been used to set the optical paths.

Optical communication network management apparatus

An optical and electronic integrated switch includes a network processor that controls the functions of the packet switch, a plurality of optical transceivers having photoelectric conversion functions, and a plurality of optical switches. The optical switches include different types of optical core switch and a plurality of optical-path selection switches. The optical transceivers provided near the processor have a regenerative relay function that regenerates optical signals and turns back the optical signals, and perform optical communication with a communication counterpart via the optical switches. In the optical communication, optical switches of the different types can cooperate to set paths for optical cut-through in which path selection is performed such that inputted optical signals are outputted without the intervention of the processor. This optical cut-through can be effectively performed without imposing a signal processing burden that consumes electric power on the processor.

A photonics-electronics convergence switch with which, even if an optical network system is built by combining a plurality of packet switches, the amount of processing in the packet switches does not increase, the optical network system operates with low electric power consumption, and this enables wide-range optical communication between the nodes of a communication origin and of a communication partner, includes a network processor that is an electronic circuit configured to control the functions of the packet switch, a plurality of optical transmitter-receivers having photoelectric conversion functions, and a plurality of optical switches. Different types of optical switches cooperate to select a path through which inputted optical signals or optical signals inputted from a different packet switch connected to the packet switch are outputted to a different packet switch without passing through the processor and a path through which inputted optical signals or optical signals inputted from a different packet switch pass through the processor and are subjected to photoelectric conversion.

A photo-electron fusion switch that can perform optical communications without any trouble, even when nodes of a communication source and a communication partner that are large in transmission capacity are connected, and makes it possible to realize a concentrated arrangement of devices having similar functions and reduce the communication processing time is connected to communication source's information processing devices and communication partner's information processing devices and information processing devices that are each different in transmission speed so as to configure an optical network system. The photo-electron fusion switch includes a network processor of an electronic circuit for controlling packet switch functions, a plurality of optical transmitter/receivers that can support coherent communications and has a photoelectric conversion function capable of transmitting and receiving optical signals different in transmission speed, an optical line switching device, and a plurality of multiplexing/separators. Each multiplexing/separator simultaneously transmits and receives respective optical signals different in transmission speed to and from the nodes via optical waveguides.

Optical and electronic integrated switch and optical network system

A signal processing apparatus includes: a coefficient update unit configured to approximate a characteristic of a transmission line of an optical signal by a first tap coefficient vector of which an L0 norm is a predetermined value or less; a zeroing unit configured to generate a second tap coefficient vector by replacing, with 0, a tap coefficient of which an absolute value is less than a threshold among tap coefficients of the first tap coefficient vector; and an adaptive filter configured to perform, based on the second tap coefficient vector, adaptive equalization processing on a digital signal corresponding to an optical signal received via the transmission line.

Signal processing apparatus, signal processing method, and program

A state estimating device includes a pre-processing unit and an estimating unit. The pre-processing unit acquires data representing at one or more of a phase of a signal transmitted from a transmission unit of a transmission device and received at a reception unit of another transmission device via a transmission path, a reception strength, a reception quality, a voltage after conversion into an electric signal, and a signal processing parameter used in reception processing, and processes the acquired data into feature data to be used for state estimation. The estimating unit estimates a state of the transmission path, an abnormal state of the transmission unit, or an abnormal state of the reception unit, on the basis of the feature data.

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Tokyo, Japan

Hideki Nishizawa