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:
Mar. 23, 2010
Filed:
Aug. 08, 2007
Yoshihiro Onoda, Kawasaki, JP;
Takashi Sekiguchi, Kawasaki, JP;
Takao Sumiya, Kawasaki, JP;
Yoshihiro Kaneda, Kawasaki, JP;
Yoshihiro Onoda, Kawasaki, JP;
Takashi Sekiguchi, Kawasaki, JP;
Takao Sumiya, Kawasaki, JP;
Yoshihiro Kaneda, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
The invention relates to an optical transmitting device. Particularly, the invention provides a loss-of-signal detecting device that detects a loss of an optical signal received by a terminal station or a relay station, in the order of an SD and an SF. The loss-of-signal detecting device includes: an optical input unit that outputs received-optical-power reduction information and a LOS alarm based on a measuring of received optical power of an optical input signal; a synchronizing unit that extracts a synchronous clock contained in the optical input signal, and outputs an LOL alarm when the clock is asynchronous; and a loss-of-signal detecting unit that determines the presence or absence of the received-optical-power reduction information, sets the LOS alarm valid based on the output of the LOL alarm when the received-optical-power reduction information is present, and immediately sets the LOS alarm valid when the received-optical-power reduction information is absent, thereby detecting a loss of signal based on a valid LOS alarm.