Fujitsu Corporation

Haruki Watanabe

Tadayuki Takada

Shinichi Kaneko

Jyunji Tanaka

An optical transmission apparatus includes a wavelength multiplexing unit that performs wavelength multiplexing with respect to dummy light for each channel of WDM and dummy light for each sub-band including the channels in plural; and a selecting unit that measures for each sub-band and corresponding to intensity of the channel-specific dummy light, transmission characteristics at a reception end, and according to measurement results, selects for each of the sub-bands, any one among the channel-specific dummy light and the sub-band-specific dummy light. The wavelength multiplexing unit wavelength multiplexes any of the channel-specific dummy light selected for each of the sub-bands by the selecting unit.

Optical transmission apparatus and dummy light inserting method

In a word synchronous system for a word interleave method in a digital communication system, the word synchronous system includes a line demultiplexing unit that receives a higher order signal for demultiplexing lower order signals therefrom; a window generating unit operatively connected to the line demultiplexing unit for generating windows to demultiplex the lower order signals from the higher order signal in the line demultiplexing unit; and a plurality of sub-demultiplexing units operatively connected to the line demultiplexing unit for receiving corresponding lower order signals from the line demultiplexing unit; wherein the window generating unit receives any one of lower order signals from the line demultiplexing unit and performs the detection of frame synchronous words from said lower order signal, when the window generating unit detects any one of frame synchronous words, the window generating unit performs a bit shift operation for the window in such a way that the bits are immediately shifted to the frame synchronous word to obtain synchronization with the window.

Growing community of inventors

Sagamihara, Japan

Haruki Watanabe