Patent ID: 6097516
Filing Date: 2000-08-01
Classification: H04J,H04Q

Abstract:
A method of configuring subnodes in an optical network ring against both node and fiber failure, the network including a unidirectional working ring and a unidirectional stand-by ring and each subnode including monitor points, selective optical filter means, optical 2.times.2 switch means and optical amplifier means, the method comprising the steps ofmonitoring inputs and outputs, respectively, of each subnode for the working and stand-by rings by monitor device means for monitoring the monitor points,generating by the monitor device means an alarm signal upon detection of signal loss at a subnode,setting, as a response to the alarm signals a new state of the subnode causing the alarm signal, said subnode being set from a first state into one of a number of possible new states as a function of the generated alarm signal, said possible new states including folding a ring in front of or behind a subnode and line switching, andselecting a switch configuration for the subnode according to the new state.