Incremental spare capacity allocation for optical networks restoration

Survivability of optical networks is one of the most relevant planning problems due to its impact on actual deployment cost. Indeed, survivability can only be achieved by deploying spare resources that will only be used under failure scenarios. In particular, the case of dual link failures on fiber optic cables (i.e., fiber cuts) has recently received much attention as repairing these cables typically takes too much time, which increases the probability of a second fiber cut. In this paper, we consider dual link failure scenarios and analyse the spare capacity allocation problem for restoration schemes, which have the potential to achieve better survivability performance than protection schemes in non-triconnected networks. However, since the traditional global optimization approach is not practical for large networks, we propose an incremental optimization approach that can find sub-optimal solutions in practical times even in large networks.