Patent ID: 8358929
Filing Date: 2013-01-22
Classification: H04J,H04Q

Abstract:
1. A network protection switching mechanism comprising: a plurality of optical switches located at a plurality of nodes; a plurality of optical communication paths between said switches; switch based fault detectors located as part of at least two switches which generate detection results representative of the identification of a fault; at least one of said fault detectors being based at a first one of said optical switches and configured to detect one of reflection and a loss of power caused by a fault between the first switch and a second one of said optical switches; at least a further of said fault detectors being based at said second switch and configured to detect one of reflection and a loss of power caused by a fault between the first and second switches; first and second switch based controllers located as part of said first and second switches; and internal switch communication means between said fault detectors and said controllers which facilitate the transmission of detection results from said first and second fault detectors to corresponding first and second controllers; wherein said first and second controllers directly cause switching to an alternative optical communication path dependent upon the receipt of said detection results; whereby autonomous switch based protection without dependence on either inter-switch control communication or higher level network control communication is achieved; and wherein at least one of said controllers is configured to identify available paths to act as alternative optical communication paths; and said at least one controller is configured to directly instruct switching to an identified available path in response to the receipt of said fault results.