Nippon Telegraph and Telephone Corporation

Kota Asaka

Katsuhisa Taguchi

Takuya Kanai

Takeshi Imai

Keita Nishimoto

Tomoaki Yoshida

Junichi Kani

Tomoya Hatano

Shunji Kimura

Yumiko Senoo

Takashi Yamada

Hirotaka Nakamura

Hirotaka Ujikawa

Takashi Mitsui

Takamitsu Tochino

Noriyuki Oota

Yukio Toyoshima

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

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

A wavelength-selective optical reception device includes a photoreceptor () that converts optical signals () into electric signals and outputs the electric signals, a base () on which the photoreceptor () is provided, a housing () that is mounted on the base () and surrounds the photoreceptor () along with the base (), and that is provided with a window () to pass optical signals () including the optical signals () and including optical signals () of a wavelength different from a first wavelength of the optical signals () and a window () to pass the optical signals (), and an optical filter () that is disposed inside the housing between the window () and the photoreceptor () along the optical axis () of the optical signals (), and that outputs, out of the optical signals () that enter thereto, the optical signals () toward the photoreceptor (), and reflects the optical signals () toward a near side in a direction of travel of the optical signals ().

Wavelength-selection type optical receiving apparatus

A station-side telescope included in a station-side optical antenna unit is configured to transmit and receive an optical signal, a guide light source is configured to emit guide light in a direction of orientation of the station-side telescope, a node-side telescope is configured to transmit and receive an optical signal, a node-side control unit included in a node-side optical antenna unit is configured to generate and output a control signal for moving a node-side base based on a position of the guide light included in an image obtained by a camera capturing the guide light emitted by the guide light source so that a direction of orientation of the node-side telescope faces the direction of orientation of the station-side telescope, an antenna drive unit is configured to receive the control signal and generate and output a drive signal based on the control signal, and the node-side base included in the node-side optical antenna unit is configured to support the node-side telescope and receive the drive signal to change a direction of orientation of the node-side telescope.

Optical space communication system and optical space communication method

An optical wavelength selecting filter-module into which light is incident from a prescribed direction determined in advance, the optical wavelength-selective filter module including: an optical filter of which an orientation can be changed; a frequency information acquiring unit which acquires frequency information that is information indicating a frequency of light to be transmitted through the optical filter; a temperature information acquiring unit which acquires temperature information that indicates a temperature of the optical filter; a determining unit which determines an orientation of the optical filter based on relationship information that is information associating, for each prescribed frequency, the temperature and an orientation of the optical filter at which light of the frequency is transmitted through the optical filter at transmittance equal to or higher than prescribed transmittance at the temperature, a temperature indicated by the temperature information, and a frequency indicated by the frequency information; and an actuator which points the optical filter in an orientation having been determined by the determining unit.

Optical wavelength selecting filter-module and optical wavelength selecting method

An information management system includes a first information storage configured to store first attribute information regarding a communication device, a second information storage configured to store second attribute information regarding the communication device, a related information storage configured to store information representing a relationship between the first attribute information and the second attribute information, a detector configured to detect update, addition, or deletion of the first attribute information or the second attribute information, and an updater configured to output a command for the update of the second attribute information associated with the first attribute information to the second information storage when the update of the first attribute information is detected, and to output a command for the update of the first attribute information associated with the second attribute information to the first information storage when the update of the second attribute information is detected.

Information management system and information management method

A wavelength-tunable optical filter control apparatus in an optical access system that uses wavelength-multiplexed optical signal of a plurality of wavelength channels includes a wavelength-tunable optical filter configured to pass an optical signal of a specific wavelength channel among the plurality of wavelength channels; a light receiving element configured to convert the optical signal that has passed through the wavelength-tunable optical filter into an electrical signal; a signal quality determining unit configured to determine a quality of the electrical signal; and a wavelength-tunable optical filter control unit configured to acquire a light intensity of the electrical signal and control a wavelength of the wavelength-tunable optical filter based on the acquired light intensity and a determination result of the quality of the electrical signal.

Tunable optical filter control apparatus and tunable optical filter control method

Transmitting devices used in an optical access system in which a plurality of the transmitting devices transmit an optical burst signal to a receiving device by time division multiple access, the transmitting devices each including an arithmetic processing unit, the arithmetic processing unit including: a data signal transmission instruction unit, the a data signal transmission instruction unit that outputs a first instruction for controlling transmission processing of a data signal on the basis of a requester's instruction; an optical signal control instruction unit that outputs a second instruction for controlling output processing of an optical signal on the basis of the requester's instruction; and an instruction output adjustment unit that adjusts a timing at which the first instruction is output and a timing at which the second instruction is output.

Transmission device, and transmission method

A virtual subscriber line terminal station device includes a software component including software to be added in accordance with a service requirement; and hardware having general-purpose functions; wherein the hardware includes a communication unit that receives a bandwidth allocation request transmitted by a subscriber line termination device; and the software component includes a bandwidth allocation component. The bandwidth allocation component has an individual unit that, based on an algorithm for allocating bands, computes a bandwidth to be allocated to the subscriber line termination device that transmitted the bandwidth allocation request; a common unit that, in accordance with the bandwidth allocated by the individual unit, allocates the bandwidth to the subscriber line termination device; and an interface between the individual unit and the common unit. The common unit converts the bandwidth allocation request received by the communication unit to a format that can be used by the individual unit. The individual unit computes the bandwidth to be allocated to the subscriber line termination device that transmitted the bandwidth allocation request that is converted, by the common unit, to a format that can be used by the individual unit.

Virtual subscriber line terminal station device and control method for virtual subscriber line terminal station device

An optical transceiver includes a wavelength-tunable transmission unit configured to transmit an optical transmission signal, a wavelength-tunable reception unit configured to receive an optical reception signal, a wavelength table configured to store a plurality of combinations of a transmission wavelength and a reception wavelength, an input terminal configured to input a wavelength selection signal, and a control unit configured to select one combination of the transmission wavelength and the reception wavelength from the wavelength table based on the wavelength selection signal, and perform transmission wavelength control for setting the selected transmission wavelength in the wavelength-tunable transmission unit as a wavelength of the optical transmission signal and reception wavelength control for setting the selected reception wavelength in the wavelength-tunable reception unit as a wavelength of the optical reception signal.

Optical transceiver and control method

An optical transceiver includes: a wavelength-tunable transmitter transmitting an optical transmission signal; a wavelength-tunable receiver receiving an optical reception signal; a wavelength table storing a plurality of wavelengths; an input terminal inputs a wavelength selection signal; and a control unit that identifies one of the optical transmission signal and the optical reception signal as a target based on the wavelength selection signal, selects the wavelength from the wavelength table based on the wavelength selection signal, performs transmission wavelength control in which the selected wavelength is set in the wavelength-tunable transmitter as a wavelength of the optical transmission signal in the case that the optical transmission signal is identified as the target, and performs reception wavelength control in which the selected wavelength is set in the wavelength-tunable receiver as a wavelength of the optical reception signal in the case that the optical reception signal is identified as the target.

An OLT configures combinations of wavelength pairs used for upstream and downstream signals, in a wavelength multiplexing optical communication system which performs single-core bidirectional transmission of a plurality of upstream and downstream signals, in such a way that the maximum value of the chromatic dispersion delay amount calculated from each wavelength pair is less than the maximum value of the chromatic dispersion delay amounts calculated when the combinations of wavelength pairs used for upstream and downstream signals are both allocated from the short wave side.

Station-side device and wavelength control method

A subscriber device includes a demultiplexer configured to demultiplex input wavelength-multiplexed light into a plurality of light signals for each wavelength, a plurality of light receivers configured to receive each of the plurality of light signals obtained through demultiplexing by the demultiplexer and to convert the light signals into electrical signals, a plurality of limiting amplifiers configured to amplify each of the plurality of electrical signals output from the plurality of light receivers, and a plurality of signal selection units configured to select a plurality of signals to be received from among a plurality of amplified signals output from the plurality of limiting amplifiers.

Subscriber device and light receiving method

In a case where a wavelength to be assigned to a subscriber-side device, to which a downstream wavelength has been assigned, is to be changed from the currently used (Source) downstream wavelength to a different changeover target (Target) downstream wavelength, a downstream wavelength changeover instruction message that indicates the change target wavelength is generated. In a case where a wavelength to be assigned to the subscriber-side device, to which an upstream wavelength has been assigned, is to be changed from the currently used (Source) upstream wavelength to a different changeover target (Target) upstream wavelength, an upstream wavelength changeover instruction message that indicates the change target wavelength is generated. The downstream wavelength changeover instruction message and the upstream wavelength changeover instruction message are respectively independently generated, and only the wavelength for which the wavelength changeover instruction message was generated is changed.

Station-side device and wavelength changeover method

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.

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Yokosuka, Japan

Kota Asaka