Fujitsu Corporation

Kouichi Maeda

Tomoyuki Sakata

Yasushi Sugaya

Hiroshi Yoshida

Akira Yamamoto

Yuichiro Sakane

Haruki Tanaka

Tsutomu Tsurumi

Hiromu Yoshii

Mamoru Suematsu

Ryuta Hoshi

Takeshi Noma

Yoshikazu Nakanishi

An optical packet signal transmission device includes a transmitting unit which includes a plurality of data delay circuits; a plurality of optical branch units which branches some of the optical packet signals as monitor lights; an optical switch which selects one of the monitor lights; a test signal generation circuit which generates a test signal which is used to adjust a delay amount in the data delay circuits; a reference optical pulse generation circuit which generates a reference optical pulse based on the test signal; an optical phase comparator which detects an relative optical phase difference by comparing the phases of the selected monitor light and the reference optical pulse; and a control circuit which sequentially sends the test signals to the data delay circuits, switches the selected monitor light, detects a relative optical phase, determines the delay amount based on a detection result, and sets the delay amount.

Optical packet signal transmission device and WDM optical communication network

An aspect of the embodiments utilizes an optical transmission apparatus which includes a rough adjustment execution portion that monitors a bit error rate of an optical signal for set values of a dispersion compensator where the set values have been set less closely to each other within a dispersion compensation control range than when a wavelength dispersion value set in the dispersion compensator is determined, and carries out a rough adjustment to determine a comparison threshold value used to set the wavelength dispersion value based on the monitored bit error rate, and a fine adjustment execution portion that monitors the bit error rate for the dispersion compensator the set values have been set more closely to each other, and carries out an adjustment to determine a wavelength dispersion value corresponding to the midpoint between the two acquired bit error rates as the wavelength dispersion value of the dispersion compensator.

Optical transmission apparatus, optical transmission method, and optical transceiver

A transponder includes a CDR section that extracts clocks from an input signal, an oscillating section that can output various frequencies to the CDR section, a frequency instruction processing section that instructs the oscillating section to output an arbitrary frequency, a detection processing section, and a frame processing section control section. The detection processing section determines whether the frequency output from the oscillating section and an input signal synchronize in frequency or not in response to an instruction by the frequency instruction processing section, and detects a synchronization frequency. The frame processing section control section operates a frame processing section based on the synchronization frequency detected by the detection processing section.

Transponder unit, transponder unit control apparatus, transponder unit control method and recording medium recording transponder unit control program

Equal-length group data obtained by grouping together slot pairs connected by a wiring pattern of equal length is stored in advance. Error rate is determined while changing a pre-emphasis (PE) setting value and an equalizer (EQ) setting value of a signal transmitted between a specified slot pair. The slot pairs belonging to the same equal-length group as the specified slot pair are selected based on the equal-length group data, and optimum PE and EQ setting values, determined based on the error rate, are set for the signals transmitted between the selected slot pairs.

Apparatus, method and computer-readable recording medium for setting signal correction-magnitude

Growing community of inventors

Fukuoka, Japan

Kouichi Maeda