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:
Aug. 04, 1998
Filed:
Oct. 29, 1996
Applicant:
Inventors:
Koji Iwamoto, Kawasaki, JP;
Akihiko Oka, Kawasaki, JP;
Assignee:
Fujitsu Limited, Kanagawa, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04J / ;
U.S. Cl.
CPC ...
370223 ; 370228 ;
Abstract
A path protection switch ring system has a working line, a protection line, and a plurality of add/drop multiplexers. The add/drop multiplexer has a path-switch unit, an unequipped signal detection unit, and a path-switch control unit. The path-switch unit is used to switch between the working line and the protection line. The unequipped signal detection unit is used to detect an unequipped signal which is output when line setting has not been carried out. The path-switch control unit is used to control the switching operation of the path-switch unit when the unequipped signal is detected.