Survivable routing and wavelength assignment performance improvement using primary-backup multiplexing with 100% fault recovery guarantee

In this paper, we address the problem of designing survivable optical networks. Path Protection (PP) and Link Protection (LP) schemes are the main means of protecting Wavelength-Division Multiplexed (WDM) networks from the losses caused by a component failure. We here propose to use a new generalization of the PP scheme called Partial Path Protection (PPP). PPP designates a different restoration path for every link failure of every primary path. Based on the PPP scheme, an Integer Linear Programming (ILP) model and a heuristic algorithm are presented to tackle the problem of establishing a set of static connections, referred to as Dependable connections (D-connections), with fault-tolerant requirements under Shared Risk Link Group (SRLG) constraints. Both approaches aim at maximizing the overall network throughput by minimizing the total bandwidth consumption using two resource sharing techniques, namely Primary-Backup Multiplexing (PBM) and Backup-Backup Multiplexing (BBM). To the best of our knowledge, this is the first attempt to combine these two techniques when routing static D-connections and performed in such a way that 100% fault-recovery is still guaranteed for all established connections. Multiple simulation studies have been carried out on different network topologies to evaluate the performance of the proposed solutions. These performance results are also compared to those of previously proposed approaches in the literature, to outline the improvements brought by our approaches.