On the Benefits of a Fast Heuristic for Backup Reprovisioning in WDM Networks

In a wavelength-division-multiplexing (WDM) optical network, backup reprovisioning (BR) provides a means to improve survivability (by protecting against multiple concurrent potential failures) and to utilize the available resources more efficiently. In particular, global backup reprovisioning (GBR), i.e. the reprovisioning involving the totality of the backup capacity has been demonstrated to be almost as capacity-effective as other re-optimization techniques involving primary paths. Unfortunately, existing ILP and heuristic solutions for the GBR problem are very time consuming and unsuitable to be adopted in time-sensitive network scenarios (e.g., subject to frequent network-status changes and/or connection-provisioning setup- time constraints). In this paper, we first analytically evaluate how the GBR computational time may impact on the connection provisioning process. Then, we propose a fast BR procedure based on simulated annealing (SA) which significantly decreases the computational time with respect to existing heuristics while still achieving very high resource efficiency.