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. 03, 1999
Filed:
Sep. 04, 1996
Thomas P Flanagan, Plano, TX (US);
Siraj E Elahmadi, Dallas, TX (US);
Northern Telecom, Montreal, CA;
Abstract
A discontinuous ring is formed by separate bidirectional optical communication links, with possibly different transmission speeds, synchronous or asynchronous transmission, and ratios of working to protection channels, each linking a pair of terminals in different nodes of a communication system. To protect protection-switched traffic on a communication link from a link failure, it is routed around the ring via the protection channel of the other communication links. To this end, an optical switch is provided between the protection channel of each link and the associated terminals in each node, and is controlled differently in nodes adjacent the link failure and in nodes not adjacent the link failure to route the protection-switched traffic accordingly. Rapid protection switching is facilitated by controlling the optical switches using wavelength detectors directionally coupled to the protection channel at each node.