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:
May. 27, 2003
Filed:
Feb. 23, 1999
Sadao Fujita, Tokyo, JP;
Koji Asahi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
Each node of an optical ring system having m nodes connected multiplexes wavelengths of &lgr;1 to &lgr;n in optical wavelength division and transmits signals. This optical ring system is composed of working optical fibers ( - and - ) and protection optical fibers ( - and - ). Each node is composed of 4×4 optical switches ( and ), a first optical preamplifier ( ), a first wavelength demultiplexer ( ), a first wavelength multiplexer ( ), a first optical booster amplifier ( ), a second optical preamplifier ( ), a second wavelength demultiplexer ( ), a second wavelength multiplexer ( ), a second optical booster amplifier ( ), a third optical preamplifier ( ), a third wavelength demultiplexer ( ), a third wavelength multiplexer ( ), a third optical booster amplifier ( ), a fourth optical preamplifier ( ), a fourth wavelength demultiplexer ( ), a fourth wavelength multiplexer ( ), a fourth optical booster amplifier ( ), and line terminals ( - to - ). In each node, 2×2 optical switches ( - to -n and - to -n) are connected in the working optical paths, and 2×2 optical switches ( - to -n and - to -n) are connected in the protection optical paths.