Impact of protection to capital and operational expenditures of optical access networks

Reliability is becoming a crucial issue for service providers, operators and users in optical access networks. The increase of network capacity and the importance of reducing service interruption times, force network operators to implement protection mechanisms in optical access networks. However, so far providing backup resources in access networks has been considered too expensive. In order to assess the impact of protection on capital and operational expenditures, the evaluation needs to study the impact to aspects such as the required infrastructure and equipment costs, failure reparation costs, and expected service interruption time. This work deals with the cost and reliability evaluation of time-division-multiplexing (TDM) and wavelength-division-multiplexing (WDM) passive optical networks (PONs). Three strategies to offer protection are evaluated: 1) provide protection in the access network directly from the greenfield, 2) invest initially on an unprotected architecture keeping in mind a future upgrade with protection resources, and 3) roll out an unprotected access network and if needed in the future, invest in deployment of protection resources. The impact of these strategies on the overall cost is studied.