Fujitsu Corporation

Tomoyuki Sakata

Akira Yamamoto

Koji Bato

Yuichiro Sakane

Kouichi Maeda

Koji Matsunaga

Tatsuya Toyozumi

Haruki Tanaka

Tatsuro Kishida

Yasushi Sugaya

Wataru Kawasaki

Taro Asao

Tatsuo Nagayoshi

Katsumi Sugawa

Hironori Kadota

Kouji Tanonaka

Tsutomu Tsurumi

Ryuta Hoshi

Seiichi Yamato

Takeshi Noma

Hiromu Yoshii

Yoshikazu Nakanishi

Noboru Kamei

Kazuyoshi Okuma

Tomonori Yamada

An optical transmitter includes a dummy optical source, a polarized wave beam coupler, and an auto gain control (AGC)-system amplifier. The dummy optical source outputs, out of an optical signal in which an optical path signal and an optical packet signal are mixed, a dummy signal having a wavelength identical to that of the optical packet signal. The polarized wave beam coupler multiplexes the dummy signal with the optical signal so that the dummy signal is orthogonal to the optical signal so as to output an output signal. The AGC-system amplifier inputs the output signal, and amplifies the output signal with a predetermined amplification factor corresponding to a power difference between input power and output power of an optical amplifier.

Optical transmitter and optical transmission method

An optical transmitter includes an amplifying unit, a monitor, an identifying unit, and a controlling unit. The amplifying unit amplifies an optical signal in which an optical packet signal is mixed in optical path signals. The monitor monitors power of the optical signal on an input stage and an output stage of the optical amplifying unit, respectively. The identifying unit identifies an optical packet signal section on the input stage side based on the monitoring result on the input stage side, and identifies an optical packet signal section on the output stage side based on the monitoring result on the output stage side. The controlling unit compares the power of the identified section on the input stage side with the power of the identified section on the output stage side, and controls an amplification factor of the amplifying unit based on a power difference resulting from the comparison.

There is provided an optical transmission device including: a packet disassembler configured to disassemble a packet into a plurality of signals having a different wavelength; an amplifier configured to amplify, for each of the wavelength, each signal into which the packet is disassembled by the packet disassembler, based on a correction value set for each wavelength; and a multiplexer configured to multiplex the respective signals amplified by the amplifier so as to transmit a packet generated by multiplexing the respective signals.

Optical transmission device and optical transmission method

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

A wavelength-multiplexing optical transmission apparatus includes an optical-wavelength-information storing unit that stores optical wavelength information on an optical wavelength of an optical signal to be output from a transponder, and an optical-wavelength-information transmitting unit that transmits the stored optical wavelength information to the transponder via a connection cable. The transponder includes an optical-wavelength control unit that controls an optical wavelength of an optical signal to be input to a wavelength multiplexing unit based on the optical wavelength information received from the optical-wavelength-information transmitting unit.

Wavelength-multiplexing optical transmission system and wavelength-multiplexing optical transmission method

The present invention provides an optical add/drop multiplexer including an optical power control unit for performing a control of an optical power by the unit of each signal light included in the wavelength multiplexed light, wherein the optical power control unit includes control logic for implementing a first control mode in which a transition to an automatic control of the optical power and release from the aforementioned control are carried out by comparing the optical power with a threshold value, and a second control mode in which a transition to an automatic control of the optical power is carried out based on control information of a notification by another of the optical add/drop multiplexers and release from the automatic control is carried out based on the comparison between the optical power and the threshold value.

Optical add/drop multiplexer, control method therefor and control program therefor

A high-speed sprchronous multiplexing apparatus has a low-speed device and a high-speed device and employs electrical signals to interface the devices with each other. The low-speed device is connected to a low-speed digital circuit. The high-speed device is connected to a high-speed synchronous multiplexing circuit. The apparatus also has a clock supplier for supplying a reference clock signal that defines a communication rate, to each of the low- and high-speed devices. The apparatus further has an alarm processor for separating faults in the low- and high-speed devices. The low- and high-speed devices are interfaced with each other with the use of the reference clock signal and electrical STM-0/STS-1 signals that employ a frame signal synchronized with the reference clock signal.

Growing community of inventors

Fukuoka, Japan

Tomoyuki Sakata