The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 11, 2008
Filed:
Jul. 26, 2004
Hiroaki Tomofuji, Kawasaki, JP;
Takuji Maeda, Kawasaki, JP;
Taizo Maeda, Kawasaki, JP;
Hideki Kobayashi, Yokohama, JP;
Tatsuo Nagayoshi, Yokohama, JP;
Tetsuo Wada, Kawasaki, JP;
Hiroaki Tomofuji, Kawasaki, JP;
Takuji Maeda, Kawasaki, JP;
Taizo Maeda, Kawasaki, JP;
Hideki Kobayashi, Yokohama, JP;
Tatsuo Nagayoshi, Yokohama, JP;
Tetsuo Wada, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical transmission system with automatic startup functions to optimize the power level of optical signals entering each optical amplifier and operate those amplifiers in appropriate mode. In the process of starting up an optical transmission system, upstream and downstream optical transmission devices set up themselves under the coordination of their internal controllers. The downstream device controller adjusts its local variable optical attenuator by utilizing optical noise emission from a post-amplifier in the upstream optical transmission device, and it selects and sets a preamplifier unit to work in appropriate operating mode. The upstream device controller, on the other hand, selects and sets operating mode of its local post-amplifier unit. During this process, the upstream and downstream device controllers exchange messages over supervisory control channels to achieve the purpose.