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. 08, 1994
Filed:
Feb. 25, 1991
Applicant:
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04J / ; H04J / ;
U.S. Cl.
CPC ...
370 8515 ; 370 855 ; 370 8512 ; 370 8514 ; 3701101 ;
Abstract
In a system control information transmission system in a ring LAN system, each of a plurality of data transmission devices transmits a transmission frame including a user information transmission area and a system control information transmission area to an adjacent data transmission device at peculiar periods independent of the state of the system, i.e., a failure in the system. The system control information transmission area in the transmission frame is used to transmit system control information only required to be relayed to a downstream data transmission device.