Nec Corporation

Hiromitu Watanabe

Takashi Yamazaki

Naoya Henmi

Hitoshi Takeshita

Shinya Nakamura

Yuuki Yoshifuji

Naoki Ando

Shuichi Iida

Kimio Ozawa

Shinobu Sasaki

Minoru Shinta

Tukasa Haga

Hitoshi Kikuchi

Youko Nakabayashi

Ryou Yamada

An optical ring system having: a wavelength demultiplexer to which wavelength-multiplexed optical signal to be sent through an optical fiber from a previous node of multiple nodes is input and in which optical signal with each wavelength assigned to itself is demultiplexed; an optical ring device which is disposed in a predetermined node of the multiple nodes to the each wavelength assigned and which is composed of a failure existence judging part which terminates an overhead of each optical signal with a wavelength demultiplexed by the wavelength demultiplexer and judges whether a failure occurs in regard to a wavelength in a previous section through which optical signal with the assigned wavelength is sent, and a switching part which, when the failure existence judging means determines the occurrence of failure, selects a path that allows optical signal with the wavelength to be transmitted to the previous node while avoiding the previous section incurring the failure; and a wavelength multiplexer which multiplexes optical signal to be output from the optical ring part and then outputs it to an optical fiber connected to a next node.

Optical ring system

Growing community of inventors

Miyagi, Japan

Hiromitu Watanabe