Fujitsu Telecom Networks Limited

Fujitsu Corporation

Reiko Sato

Shota Mori

Tomoko Osaki

Masato Iwawaki

Takashi Fujiki

Hiroshi Yakushiji

An optical packet transmitting/receiving system includes an optical packet transmitting apparatus for generating a copied optical packet signal of an original packet signal to be transmitted and for transmitting the copied optical packet signal after the original optical packet signal, an optical packet receiving apparatus for performing an error recovery processing based on the copied optical packet signal of the original optical packet signal, when an error occurs with the received original optical packet signal, and an optical packet switching apparatus. When congestion occurs between a copied optical packet signal inputted to an input port and an original optical packet signal inputted to another input port, the optical packet switching apparatus preferentially passes the original optical packet signal.

Optical packet transmitting/receiving system

An optical packet switching system includes a plurality of network elements for transmitting and receiving optical packet signals. Each network element includes an optical signal-to-noise ratio (OSNR) acquiring unit for acquiring the OSNR of each optical packet signal, an average value calculating unit for calculating the average value of the OSNRs of optical packet signals received within a predetermined time duration for each of the plurality of source network elements, and a difference information transmitter for calculating the difference between the calculated average value of the OSNRs and a target value of the OSNRs and then transmitting the difference to a network element corresponding to the difference. A source network element that has received the difference information adjusts the characteristics of an optical packet signal to be transmitted in a manner such that the difference is reduced.

Optical packet switching system

An optical packet switching system includes: an optical packet switching device configured to route and output an input optical packet signal; an optical amplifier device provided in a stage subsequent to the optical packet switching device; and a control signal generation unit configured to superimpose a noise component on the optical packet signal by inducing cross talk in the optical packet switch.

An optical packet switching apparatus includes (i) an optical packet switch for switching the route of an inputted optical packet signal and outputting the inputted optical packet signal, (ii) an input-side packet density monitoring unit for detecting the packet density of optical packet signals inputted to the optical packet switch, (iii) a first input-side optical amplifier provided on an input side of the optical packet switch, (iv) a first input-side variable optical attenuator (VOA) provided posterior to the optical amplifier, (v) a storage for storing the gain characteristics in relation to the packet density at the first input-side optical amplifier, and (vi) an input-side VOA control unit for controlling the attenuation by the first input-side VOA in such a manner as to compensate for the gain fluctuations due to the variations in the packet density at the first input-side optical amplifier, based on the packet density and the gain characteristics.

Optical packet switching apparatus, optical packet switching system, and optical packet in-line amplifier apparatus

An optical packet switching system includes: an optical packet transmitter device configured to transmit an optical packet signal; and an optical packet switching device configured to route and output an input optical packet signal. The optical packet transmitter device is configured to adjust gap time between optical packets transmitted. The optical packet transmitter device adjusts the gap time to a fixed value defined by time required for switching in the optical packet switching device.

Optical packet switching system and optical packet transmitter device

An optical packet switching system includes: an optical packet switching device configured to route and output an input optical packet signal; an optical amplifier device provided in a stage subsequent to the optical packet switching device; and a dummy packet insertion device configured to insert a dummy packet in an optical packet signal prior to input to the optical amplifier device. A dummy packet includes a flag indicating that the packet is a dummy packet.

In the master control unit, updated information is transferred to a slave control unit and a coherence of information between the master control unit and the slave control unit is periodically checked, thereby eliminating a difference of the internal information of the two units which execute a control, a status monitor, and a maintenance of a computer system in an on-line manner and guaranteeing the coherence. When the master control unit recognizes a difference between the information for a predetermined time or more, the slave control unit is halted and the information of the master control unit is made effective. With respect to an abnormality of the master control unit, the master control unit halts by itself. In this instance, the slave control unit is shifted to the master status and takes over the process.

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Kawasaki, Japan

Reiko Sato