Shared path protection with differentiated reliability

The authors (Fumagalli and Tacca (2001)) introduced the concept of differentiated reliability (DiR) applied to dedicated path protection (DPP) switching in wavelength division multiplexing (WDM) rings. By means of the DiR concept, a network can be designed to provide multiple degrees of reliability and efficiently satisfy the user-specific requirements, yet minimizing the network total cost. This paper extends the DiR concept to the case of shared path protection (SPP) switching in arbitrary (mesh) topology, the so called SPP-DiR. A time efficient algorithm is proposed to determine the primary and backup path of each demand in both conventional SPP and SPP-DiR (WDM) networks. When compared to DPP, results obtained for the pan-European network by using the proposed algorithm indicate cost reductions of about 16% when SPP is applied, and up to 34% when SPP-DiR is applied.