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:
Jun. 22, 2004
Filed:
Nov. 27, 2000
Masayuki Tanaka, Kanagawa, JP;
Masaki Kubo, Kanagawa, JP;
Satoshi Nemoto, Kanagawa, JP;
Shuji Sakakura, Kanagawa, JP;
Shigeo Handa, Kanagawa, JP;
Yuji Kamura, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A non-interruptive protection switching device which performs protection switching in a more efficient and robust way. The device has a working-channel signal storage unit to store data signals received through a working channel. Multiframe synchronization timings are detected by a working-channel multiframe synchronization controller, which provides a working-channel multiframe sync detection pulse signal when the main signals are in a normal condition and stops it when the channel is disrupted. A working-channel write controller controls every write access to the working-channel signal storage unit, generating a write pulse signal therefor. The working-channel write controller also produces working-channel write phase data by identifying a phase difference of the detected multiframe synchronization timing with respect to a reference phase signal. The generation of this write pulse signal is based on the multiframe sync detection pulse signal when the working-channel multiframe sync detection pulse signal is available, or on a free-running timebase when it is stopped. The stored data in the working- and protection-channel signal storage units are read out simultaneously, under the control of a read controller which produces read pulses from the write phase data.