Routing and spectrum assignment for 1+1:1 lightpath services in elastic optical networks

This paper extends single failure to dual failure recovery for an elastic optical network (EON) with 1+1:1 network protection. The issue of routing and spectrum assignment (RSA) is studied with objective of minimizing the maximal number of frequency slots (FSs) used. The key principle for protection capacity sharing among second protection lightpaths is identified. An Integer Linear Programing (ILP) model and a spectrum window plane (SWP)-based heuristic algorithm are developed for RSA of 1+1:1 protected EON. Simulation results show that the proposed SWP-based algorithm can achieve better capacity utilization than the shortest-path (SP) algorithm and is almost as efficient as the ILP model.