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:
Apr. 24, 2001
Filed:
Mar. 31, 1998
Koji Asahi, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A device comprises a plurality of nodes and four optical transmission lines of clockwise and counter-clockwise working operation lines and clockwise and counter-clockwise stand-by lines which connect the nodes in form of a ring. Each node is provided with first and second terminal sections including a receiver and transmitter, with a first optical path switch for switching the optical path between four output terminals of the counter-clockwise working operation and stand-by optical transmission lines, the second terminal section, and output terminal of a first stand-by line, and four input terminals of the clockwise operation and stand-by optical transmission lines, first terminal sections, and a second stand-by line. Each node is also provided with a second optical path switch for switching the optical path between four output terminals of clockwise operation and stand-by optical transmission lines, and first terminal section, and output terminal of the second stand-by path, and four input terminals of the counter-clockwise working operation and stand-by optical transmission lines, second terminal section, and input terminal of the first stand-by path.