A Comparative Study on Shared Precomputed Restoration and Shared Backup Path Protection in EONs

This paper proposes a shared precomputed restoration (SPR) mechanism for link failures in translucent elastic optical networks (EONs). We present SPR with a heuristic algorithm that aims to minimize a cost function. The cost function depends on the number of transceivers and frequency slots (FSs) used to establish a working/protection lightpath (LP) with a tunable parameter that determines the weight of the number of transceivers and FSs in the cost function. SPR precalculates a protection LP for all links of each working LP. As a result, non-link-disjoint working LPs can share protection spectrum and transceivers on newly eased conditions. Like shared backup path protection (SBPP) and dedicated protection (1+1), SPR guarantees single link failure recovery. Our simulation results reveal that SPR outperforms SBPP in terms of recovered bandwidth in multiple link failures. Furthermore, SPR uses fewer transceivers compared to SBPP and 1+1 protection.