Robust FIPP p-cycles against dual link failures

Design of efficient node p-cycles in WDM mesh networks

“…Later, Kodian and Grover [3] proposed FailureIndependent Path-Protecting (FIPP) p-cycles, and Jaumard et al [8] Failure-Dependent Path-Protecting (FDPP) pcycles to provide end-to-end path protection. If node disjointness is required instead of only link disjointness for all the paths to be protected by a single unit FIPP p-cycle, 100% node protection (excluding the endpoints of the working paths) can be guaranteed.…”

“…This is ensured by constraints (7). Constraints (8) and (9) are used to identify straddling links. A link straddles a cycle if its two end nodes are on the cycle, but the link itself is not.…”

“…We re-use the column generation formulation of [4,8] and adapt it in order to guarantee 100% node protection. Note that we consider here, as in [4], a decomposition of the pricing problem in order to further enhance the CG model scalability as path p-cycles are more costly (with respect to computing times) to compute than link p-cycles.…”