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:
Jul. 17, 2001
Filed:
Oct. 02, 1998
Yuji Shiraishi, Kawasaki, JP;
Ichiro Ayukawa, Kawasaki, JP;
Kimihiko Yoshimura, Kawasaki, JP;
Hisamichi Hazama, Kawasaki, JP;
Kimio Watanabe, Kawasaki, JP;
Shingo Mizuno, Kawasaki, JP;
Tadayuki Sakama, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
When a wireless channel fails, a working signal and a protection signal are synchronized and switching is performed without instantaneous disconnection. Each working unit of a plurality of working units is provided with a wireless-channel failure detector for detecting a failure that has occurred in a working wireless channel; a synchronization detecting circuit for detecting synchronization between a working wireless channel and a protection wireless channel; a changeover switch for selecting a signal from either the protection wireless channel or a working wireless channel without instantaneous disconnection; and a unit failure detector for detecting a failure that requires switching of a unit. When a failure develops in a wireless channel and a working wireless channel and the protection wireless channel are synchronized, a radio protection switching device controls the changeover switch to switch between working and protection wireless channels without instantaneous disconnection. Further, when failure that requires switching of a unit occurs, the radio protection switching device controls a unit changeover switch to switch between a working unit and the protection unit.