Fujitsu Corporation

Fujitsu Telecom Networks Limited

Koji Tanonaka

Kenji Watanabe

Tomoyuki Suzuki

Akihisa Kawaguchi

Naoto Kidoku

Hiroyuki Suzuki

Takehiro Fujita

Motoshi Hamasaki

Toshikazu Magome

A transmission system is provided with a transmission apparatus that outputs an ASE light from a transmission light amplifier and with a reception apparatus provided with: a tilt detection unit that detects the optical strength levels of at least two probe lights having different wavelengths from a received ASE light; and a reception light amplifier that performs a first-order tilt correction on light to be output in a linear manner so as to reduce the difference in the optical strength level of the two probe lights detected by the tilt detection unit.

Transmission system and method of correcting tilt of the transmission system

An integrated transmission apparatus includes a plurality of optical supervisory channel (OSC) processing units for processing OSC signals contained in a wavelength division multiplexing (WDM) signal received from a WDM network and a switching unit for performing the path control of synchronous digital hierarchy (SDH) frames. An OSC processing unit transmits the SDH frame, containing wavelength information indicated by, to the switching unit. Another OSC processing unit acquires the SDH frame, containing wavelength information, from the switching unit and sets an OSC signal which is to be appended to the WDM signal to be transmitted, based on the wavelength information.

Transmission apparatus, transmission controlling method, and optical supervisory channel (OSC) processing apparatus

A transmission apparatus utilizing an SDH is provided. The transmission apparatus includes a processing unit controlling the transmission apparatus, an SSM extraction unit extracting a first SSM from an input signal, and a selector selecting either of the first SSM and a second SSM set by the processing unit. The transmission apparatus can add an incoming SSM function, for instance, to an external 2 Mbps SSM function in addition to an assumed SSM function. Accordingly, the transmission apparatus can conform to the ITU-T G.781 Recommendation by utilizing a related-art synchronization function.

Transmission apparatus

The invention concerns synchronization equipment; more particularly, the invention is directed to the provision of synchronization equipment which, after simple hardware installation and software setting, establishes a synchronization network with an existing network, SDH elements, etc. that do not support SSMB. The synchronization equipment comprises: a failure detection section for detecting a failure of each of a plurality of timing sources assigned prescribed priorities; a failure monitoring section for monitoring failure detection information from the failure detection section, and for outputting in the event of detection of a timing source failure a timing source switching control signal directing switching to a timing source having the highest priority among the timing sources other than the failure-detected timing source; a timing source selection section for outputting a timing source switching control signal based on the quality of synchronization derived from SSMB information; and a selection section for selecting one or the other of the two timing source switching control signals.

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Kanagawa, Japan

Koji Tanonaka