Fujitsu Corporation

Toshihisa Kyouno

Hideyuki Miyata

Nobuyuki Kobayashi

Masaji Noguchi

Kenichi Miyama

Noboru Shimizu

Yutaka Kai

Yasuhiko Aoki

Tetsuo Wada

Tomohiro Ueno

Yasushi Tateno

Kazumaro Takaiwa

Yoshihisa Funami

Yoshiaki Shibayama

Hiromitsu Yanaka

Akinori Nishiie

A transmission apparatus includes: a first plug-in unit including: a clock generator to generate a first clock, a first frame-pulse generator to generate a first frame-pulse-signal based on the first clock; a detector to detect a phase-difference between a first phase of the first frame-pulse-signal and a second phase of a second frame-pulse-signal transmitted from other plug-in unit, and generate phase-difference information based on the phase-difference, and a first transmitter to transmit a control-signal including the phase-difference information to the other plug-in unit; and a second plug-in unit being the other plug-in unit, including: a receiver to receive the control-signal, a controller to control a phase of a second clock of the second plug-in unit, based on the phase-difference information, a second frame-pulse generator to generate the second frame-pulse-signal based on the second clock, and a second transmitter to transmit the second frame-pulse-signal to the first plug-in unit.

Transmission apparatus and plug-in unit

An FPGA configuration device comprises: a read operation control unit which performs control to read configuration data from a configured FPGA; and a configuration data transfer unit which transfers the configuration data read out of the FPGA to a memory.

Configuration device for configuring FPGA

A configuration data feeding device for feeding configuration data to a plurality of FPGAs includes a memory for storing configuration data that are fed to the plurality of FPGAs, a plurality of interface units for outputting the configuration data read out from the memory, according to their specific configuration layouts, an interface selection unit for selecting, out of the plurality of interface units, an interface unit that is to be used for configuring each of the plurality of FPGAs, and a circuit-switching unit for switching the circuits that connect the FPGAs to the interface units depending upon the selection by the interface selection unit.

Configuration data feeding device

A method of wavelength selection control is disclosed. The method includes detecting reference RF frequencies by varying the frequency of a RF signal supplied to a reference acousto-optic tunable filter with the reference RF frequencies corresponding to reference wavelengths of reference signals input to the tunable filter, performing tracking to optimize the reference RF frequencies, calculating dependent RF frequencies corresponding to wavelengths of WDM transmission signals and recording the calculated dependent RF frequencies in a first register, repeating the above when a request of wavelength selection is not received, when a request of wavelength selection is received, selecting one of the dependent RF frequencies corresponding to the requested wavelength and recording the selected dependent RF frequency in a second register for use of an acousto-optic tunable filter at a port in operation, and generating and supplying a RF signal having the selected dependent RF frequency to the acousto-optic tunable filter.

Method of wavelength selection control and wavelength variable filter device

A drop-type AOTF is used as a configuration for removing from a through signal an optical signal having the same wavelength as that of an optical signal to be added. To the drop-type AOTF, RF signals are input to always select all of wavelengths, and an RF signal is not input for a wavelength desired to be rejected. As a result, the optical signal having the wavelength for which the RF signal is stopped is not selected by the drop-type AOTF, and cannot pass through. Since there is only one RF signal whose input is stopped, a 'drawing effect' does not occur, and control of an optical add/drop device is simplified. Additionally, since high-speed switching can be made, and a wavelength to be added can be varied, restrictions are not imposed on a network configuration.

Optical add/drop device

An optical multiplex communication system includes a transmission part and a receiving part, wherein the transmission part includes a transmission quality detecting part which measures and transmits a transmission quality information for the channels based on a request from the transmission part; the receiving part includes a variable optical attenuation part controls the optical signal level for the channels, an optical level setting part controls the variable optical attenuation part based on a setting value, a setting control part adding the setting value to the optical level setting part based on a request for setting.

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Kawasaki, Japan

Toshihisa Kyouno