A new shared path protection scheme in WDM optical networks

Network survivability is a crucial requirement in high-speed optical networks. In this paper, we consider the problem of path protection schemes in WDM (Wavelength division multiplexing) networks with dynamic traffic demands. A new path protection method is proposed, i.e. SRLG-based shared path protection (SRLG-SPP). The SRLG (Shared risk link group) constraint defines the availability of protection resources to a working path, which requires that any two working paths sharing the same risk of failure (or in the same SRLG) cannot share the same protection resources. Furthermore, in our study, we consider a more practical single-link failure model, in which the link-failure-interarrival-time and link-failure-holding-time are considered as two independent factors. Based on this link-failure model, extensive numerical simulations are done to compare the resource utilization, protection efficiency and service disruption ratio between SRLG-SPP, Shared path protection (SPP) and Dedicated path protection (DPP) schemes. We show that the developed SRLG-SPP protection scheme performs very well in terms of protection efficiency and service disruption ratio, while it will sacrifice some performances in terms of resource utilization.