Fujitsu Corporation

Rikiya Watanabe

Takuya Miyashita

Motoyoshi Sekiya

Yasushi Sugaya

Hiroaki Tomofuji

Taizo Maeda

There is provided a network management device to manage a network on which an existing optical path is operated, the network management device including: a first receiver configured to receive data related to a measurement result of signal quality of a first optical signal having a first wavelength on the existing optical path; a second receiver configured to receive a request for adding a second optical signal having a second wavelength to the existing optical path; at least one memory configured to store a procedure; and at least one processor configured to execute the procedure of estimating a variation quantity in the signal quality of the first optical signal when the second optical signal is added to the existing optical path based on the data related to the measurement result, when the request is received, and determining whether to add the second optical signal based on results of the estimating.

Network management device and network management system

A design method includes calculating a calculated compensation amount of a dispersion compensation module arranged on each of a plurality of wavelength paths in such a way that a residual chromatic dispersion value of each of the wavelength paths which transmits an optical signal between an initial node and a final node satisfies a tolerance condition given in accordance with a priority given to each of the wavelength paths; and deciding a decision value to be applied as the compensation amount of the dispersion compensation module based on the calculated compensation amount based on a plurality of candidate values each being prepared in advance as the candidate for the compensation amount of the dispersion compensation module.

Method and device for designing chromatic dispersion compensation

A communication system is provided for communicating over a network. A plurality of transmission devices are disposed within a network and connected by transmission channels. A control device calculates initial data required during an initial operation of the transmission devices and sets the initial data to the transmission devices. The transmission devices perform reception processing using maximum likelihood sequence estimation, and the control device obtains, as the initial data, with respect to paths that are signal communication pathways between the transmission devices and in accordance with transmission states of individual paths, initial likelihood information that is initial-stage likelihood information for performing the maximum likelihood sequence estimation.

Communication system using initial likelihood information for performing maximum likelihood sequence estimation (MLSE)

An optical amplifier to reduce signal loss by reducing crosstalk, and method therefor. A demultiplexer isolates an optical signal into a first wavelength band and a second wavelength band. The first and second wavelength bands are separately amplified in first and second optical amplifiers, respectfully, first and second optical amplifies each including cutoff filters to cutoff the wavelength band not corresponding to the particular amplifier. Optical receiving elements monitor light input to the first and second optical amplifiers and receive crosstalk signals on an output side.

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Kawasaki, Japan

Rikiya Watanabe