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:
Aug. 02, 2005
Filed:
May. 19, 2003
Thomas Pfeiffer, Stuttgart, DE;
Thomas Pfeiffer, Stuttgart, DE;
Alcatel, Paris, FR;
Abstract
Passive optical networks are generally built from a central office and a plurality of passive optical nodes. Over a main path, optical signals are transmitted to the nodes. When a fault, e.g. a cable break, occurs on the main path, the optical signals are transmitted to the nodes over a reserve path. When the fault has been removed, switchback to the main path is effected and the optical signals are again transmitted to the nodes over the main path. The device according to the invention is particularly characterized in that an additional optical signal is provided which is transmitted at a wavelength outside the wavelength range used for the transmission of useful optical signals over the main path, and which is used to power an electric circuit within the device which, in turn, controls a switch that switches between main path and reserve path.