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:
Feb. 27, 2001
Filed:
Dec. 03, 1997
Applicant:
Inventor:
Koji Asahi, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B 1/000 ; H04B 1/024 ; H04B 1/700 ;
U.S. Cl.
CPC ...
H04B 1/000 ; H04B 1/024 ; H04B 1/700 ;
Abstract
A ring network is composed of an even-number of optical fibers wherein each pair of optical fibers forms a bidirectional transmission line and a plurality of nodes coupled through the optical fibers in ring topology. In this ring system, each of the nodes includes the even-number of Add/Drop circuits coupled to the optical fibers, respectively, and the even-number of optical transceivers each including an optical transmitter and an optical receiver. A switch changes a combination of an Add/Drop circuit and each of the optical transmitter and the optical receiver.