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:
Nov. 07, 2000
Filed:
Jul. 02, 1998
Jun Wakabayashi, Yokohama, JP;
Kazuhiko Shiba, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A clock regeneration apparatus which regenerates and distributes a timing signal in a synchronous data transmission network. The network is organized by a plurality of transmission units being linked in a ring topology, and at least two transmission units have external clock sources for synchronization purposes. The clock regeneration apparatus, disposed in each transmission unit, has a clock source list that contains entries for at least two line clock sources provided from neighboring transmission units. A clock selection controller selects a reference clock source with which the transmission unit is to be synchronized. A clock quality transmitter supplies one of the two neighboring transmission units that is not selected as the reference clock source by the clock source selection controller, with a message requesting not to use a corresponding line clock source for synchronization. This message transmission occurs only when the transmission unit is configured as a slave unit, and when the clock quality messages received from the neighboring transmission units exhibit equal clock quality levels continually for a predetermined period.