On Spectrum Efficient Failure-Independent Path Protection p-Cycle Design in Elastic Optical Networks

High spectrum efficiency and fast restoration speed are highly desired for survivable elastic optical networks (EONs). In this paper, we take the advantages of failure-independent path-protecting preconfigured cycles (FIPP p-cycles) and investigate how to realize spectrum efficient resilience design with them. We first study the problem of offline service provisioning with FIPP p-cycles. We formulate an integer linear programming model and prove that the problem is NP hard. Then, several time-efficient heuristics are designed for FIPP p-cycle formulation and related routing, modulation format, and spectrum assignment. Extensive simulations on offline provisioning verify that the heuristics can obtain near-optimal solutions. Next, we consider online service provisioning with FIPP p-cycles in dynamic EONs. In order to overcome the decrease of protection efficiency during dynamic network operation, we propose a p-cycle reconfiguration scheme to reoptimize protection structures on-the-fly. Simulation results demonstrate that the proposed algorithms can improve spectrum efficiency and reduce bandwidth blocking probability simultaneously.