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:
Dec. 17, 1996
Filed:
May. 08, 1995
Applicant:
Inventors:
Yukio Nakano, Zama, JP;
Keiji Tomooka, Yokohama, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04J / ; H04J / ;
U.S. Cl.
CPC ...
370376 ; 359117 ; 370388 ;
Abstract
An add-drop multiplexer having a plurality of OC--N and OC--M (M <N) interfaces and a drop and insertion unit. The drop and insertion unit includes a plurality of switch units corresponding to the second stage switch and a plurality of first and third stage time slot interchange circuits provided on the side of a plurality of low speed side interfaces. A multiplexing signal can be linked between low speed side transmission lines by using simple circuits.