CAPEX Costs of Lightly Loaded Restorable Networks under a Consistent WDM Layer Cost Model

Shared protection promises the benefits of lower network capacity utilization without sacrificing the availability level of dedicated protection. Shared protection is often evaluated in terms of its spare capacity efficiency, but seldom in terms of real-world CAPEX (capital expenditure) costs. In this paper, we investigate the design of several shared protection architectures under a standardized cost model for the WDM layer, developed recently within the European NOBEL project. This paper presents a comparative study of the implementations and costs of these architectures under this model. Findings show a counterintuitive relationship between network capacity utilization and design cost when the network is lightly loaded.