How much to pay for protection in fiber access networks: Cost and reliability tradeoff

The economical aspects are most critical in the access part of the networks because of the low sharing factor of the total cost. It makes the deployment of fiber access networks relatively slow due to the high investment cost involved. Several fiber access network architectures such as homerun (sometimes referred to as point-to-point P2P), active optical networks (AONs) and passive optical networks (PONs) have been developed to support the growing bandwidth demand from both residential and business customers. Meanwhile, fault management and reliable service delivery becomes more significant due to increased dependency on electronic services all over society and the growing importance of reliable service delivery. However, there is a tradeoff between the cost of protection and the level of service reliability. Obviously, in the access part of the networks, improving reliability performance by duplication of network resources (and capital expenditures CAPEX) can be too expensive. Therefore, a real challenge for an access network operator is to operate a cost-efficient, yet reliable network that provides leading edge services at low price and with minimal downtime. In this paper we present the evolution of fiber access networks and compare reliability performance in relation to investment and management cost for some representative cases. We consider both standard and novel architectures for deployment in both sparse and dense populated areas. While some recent works focused on PON protection schemes with reduced CAPEX the current and future effort is put on minimizing the operational expenditures (OPEX) during the access network lifetime.