Protection cost evaluation of WDM-based next generation optical access networks

Abstract

New technologies and advanced network devices make it possible to move towards high capacity access networks able to satisfy the growing traffic demand. Wavelength division multiplexing (WDM) is considered as one of the promising technologies for the next generation access networks since it offers higher bandwidth and longer reach compared to the current technologies (such as time division multiplexing (TDM) based networks). However, the migration to a new technology is typically based on an overall techno-economic study which should assure the network operator that the new implementation is cost effective and profitable while able to provide the required services to the users. Another important aspect in the access network design is the network reliability performance, which can be improved by providing a certain level of protection for equipment and/or infrastructure with high failure impact ratio in order to prevent a big number of the users being affected by a single failure. The cost of protection should be carefully evaluated since providing the backup resources may be too expensive for a network operator.In this paper, we investigate the capital and operational expenditures for two next generation optical access (NGOA) networks based on the WDM technology in dense urban areas. Three scenarios with different splitting ratios are studied for each technology, with and without protection. The aim of this work is to investigate the impact of providing protection on the total cost of NGOA networks. The results show that in the dense urban areas the fibers and digging costs are highly shared among the end users but still vary according to the splitting ratios for different scenarios and the fiber layout. It also can be seen that with a proper fiber layout design, minor extra investment for protection of NGOA networks can make a significant saving on failure related operational cost and that operational expenditures depend significantly on the fiber layout.