Patent ID: 9559770
Date: 2017-01-31
CPC Classifications: H04B,H04J,H04Q

Claim:
1. A method of dynamic restoration by routing and bandwidth assignment of an unplanned restoration path in a wavelength switched optical network, to restore a traffic flow after a fault, the wavelength switched optical network having multiple nodes, of which one or more are regeneration nodes, the regeneration nodes each having a ROADM having optical drop paths and optical add paths, the regeneration nodes also having electrical drop paths coupled by O/E converters to respective ones of the optical drop paths, electrical add paths coupled by E/O converters to the optical add paths, and an electrical switch for making interconnections between the converters to provide configurable regeneration capacity by coupling selected ones of the electrical drop paths to respective selected ones of the electrical add paths, the method comprising: before the fault, determining what bandwidth is currently available between at least some of the nodes, and how much of the configurable regeneration capacity is currently available at the regeneration nodes; restricting assignment of at least some of the configurable regeneration capacity so that at least some remains available for unplanned restoration paths, and, after detection of the fault; determining routing and bandwidth assignments for the unplanned restoration path for the traffic flow avoiding the fault, and if needed, assigning some of the currently available configurable regeneration capacity to the unplanned restoration path; sending configuration messages to the nodes of the determined route to set up the unplanned restoration path dynamically and to configure the electrical switch at a respective one of the regeneration nodes according to the assignment of regeneration capacity, and to reroute the traffic flow onto the unplanned restoration path.