Fujitsu Corporation

Hiroshi Iizuka

Hiroyuki Itou

Kosuke Komaki

Takeshi Sakamoto

Tsukasa Takahashi

Yoshio Shimano

Hisayuki Ojima

Kaoru Usui

Kousuke Komaki

A transmission apparatus includes: a module configured to receive and transmit data externally, the data received and to be transmitted being transferred via an interface internally; a framer configured to process transmission and reception of the data processed by the module; a transmission channel on which predetermined data is transmitted and received to and from the framer; and a controller configured to determine a combination of setting values for transmission and reception in accordance with a surrounding environment of the transmission channel, based on an error rate when the predetermined data is transmitted and received for each combination of setting values for transmission and reception on the transmission channel, and to perform setting for transmission and reception via the interface, based on the determined combination of setting values for transmission and reception.

Transmission apparatus, line card and control method of transmission apparatus

A card control unit for controlling a line card includes a detecting section, a collecting section, and an estimating section. The detecting section detects mounting of a module into a mounting port in the communication card equipped with multiple cages that each have a mounting port into which a module is removably mounted. When mounting of a module has been detected, the collecting section collects an environmental temperature around a mounting port into which the module has been mounted, a power consumption and specified temperature of the module, and thermal resistance information of a cage mounted with the module. The estimating section estimates an environmental temperature after activation of the module on the basis of the collected environmental temperature, power consumption, specified temperature, and thermal resistance information before the module of which the mounting has been detected is activated.

Monitoring control device, monitoring control method, and recording medium

There is provided an optical receiving apparatus, including a receiver configured to perform coherent reception by mixing first light of a received optical signal and second light generated by a local oscillator, a monitor configured to monitor a first frequency of the first light, and a controller configured to control a second frequency of the second light, based on a difference between the first frequency and the second frequency so as to reduce the difference.

Optical receiving apparatus

An optical transmission apparatus receives an optical signal of an optical wavelength. The optical transmission apparatus has a variable wavelength filter, a neighboring frequency detection unit, and an ADC/DSP. The variable wavelength filter detects a neighboring of another optical transmission apparatus that receives an optical signal of a wavelength different from the wavelength. The neighboring frequency detection unit determines whether or not a second frequency supported by the another optical transmission apparatus where a neighboring has been detected by the variable wavelength filter is different from a first frequency supported by the optical transmission apparatus. The ADC/DSP changes a parameter for removing a phase noise from the optical signal of the wavelength according to a difference between the first frequency and the second frequency when it is determined that the second frequency is different from the first frequency.

Optical transmission apparatus and optical transmission method

An optical receiving apparatus includes: a compensator configured to compensate an amount of change in a characteristic; a controller configured to obtain, based on a first amount of change in the characteristic with respect to a first optical signal with a first wavelength, the first wavelength, and a wavelength characteristic in the characteristic, a second amount of change in the characteristic made when a second optical signal with a second wavelength is propagated in an optical path, the second wavelength being different from the first wavelength, and obtain a compensation amount based on the second amount of change; and a first setting unit configured to set the compensation amount for the compensator so that the compensator compensates the amount of change in the characteristic.

Optical receiving apparatus and characteristic compensation method

An optical transmission apparatus includes a non-reciprocal device including first to second ports, an optical signal input from the first port being provided to the second port, an optical signal input from the second port being provided to the first port, a dispersion compensator that is coupled to the first port of the non-reciprocal device and that conducts given processing to an optical signal input from the first port of the non-reciprocal device to provide the optical signal subjected to the given processing to the second port of the non-reciprocal device, a first monitor, a second monitor, and a fault determination device that compares a value monitored by the first monitor with a value monitored by the second monitor to determine one of a connection failure, at least at one of the first port, the second port, of the non-reciprocal device and a connection state of the dispersion compensator.

Optical transmission apparatus and fault detection method

In an optical transmission apparatus, a unit includes a first connection section, a second connection section, a branching section, a first detection section, and a second detection section. The first connection section connects to a first component. The second connection section connects to a second component. The branching section is disposed at a preceding stage of the second connection section and outputs signal light to the first component through the first connection section. The first detection section determines whether the first component receives the signal light output from the branching section. The second detection section is disposed at a subsequent stage of the second connection section and detects the signal light.

Optical transmission apparatus

A photo amplifying apparatus for amplifying wavelength division multiplexed signals includes a specific wavelength measuring unit for measuring a specific wavelength at a measuring point, a total power measuring unit for measuring all wavelengths at the measuring point, and an output control unit for controlling the output of the photo amplifying apparatus based on the light power measured by the specific wavelength measuring unit and the total power measuring unit. Since the photo amplifying apparatus measures both the specific wavelength and all wavelengths, the photo amplifying apparatus can determine change in the number of multiplexed wavelengths and the gain gradient of the photo signals, and can properly control its output level.

Optical amplifying apparatus for wavelength division multiplexed signals

There are provided an ASE correction unit which corrects control errors regarding either or both of the gain and the output level of the optical amplifier, which control errors are generated due to the ASE, and an ASE correction controller which controls the correction of the control errors by these ASE correction unit based on a predetermined time constant. Accordingly, the ASE correction errors of the optical amplifier, which performs the ASE correction are suppressed, and stabilization of the output signal light level and the optical amplification gain at the time of changes of the wavelength number can be attained.

Control device and control method of optical amplifier

An optical amplifier includes first and second optical amplifier units, a variable optical attenuator optically coupled between the first and second optical amplifier units, a first control unit to control gains of the first and second optical amplifier units based on an input of the first optical amplifier unit and an output of the second optical amplifier unit, and a second control unit to control an attenuation quantity of the variable optical attenuator based on the input and an output of the first optical amplifier unit and an input and the output of the second optical amplifier unit.

Optical amplifier and optical amplifier control method

The optical amplifier according to the present invention includes a first optical amplifying unit, a second optical amplifying unit, a variable optical attenuator optically connected between the first and second optical amplifying units and a first control unit for controlling the gains of the first and second optical amplifying units according to an input to the first optical amplifying unit and an output from the second optical amplifying unit, and a second control unit for controlling the attenuation of the variable optical attenuator according to an input to and an output from the first optical amplifying unit and an input to and an output from the second optical amplifying unit.

Growing community of inventors

Kawasaki, Japan

Hiroshi Iizuka