Fiber Access Networks: Reliability Analysis and Swedish Broadband Market

Abstract

SUMMARYFiber access network architectures such as active optical networks (AONs) and passive optical networks (PONs) have been developed to support the growing bandwidth demand. Whereas particularly Swedish operators prefer AON, this may not be the case for operators in other countries. The choice depends on a combination of technical requirements, practical constraints, business models, and cost. Due to the increasing importance of reliable access to the network services, connection availability is becoming one of the most crucial issues for access networks, which should be reflected in the network owner's architecture decision. In many cases protection against failures is realized by adding backup resources. However, there is a trade off between the cost of protection and the level of service reliability since improving reliability performance by duplication of network resources (and capital expenditures CAPEX) may be too expensive. 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 sparsely and densely populated areas. While some recent works focused on PON protection schemes with reduced CAPEX the current and future effort should be put on minimizing the operational expenditures (OPEX) during the access network lifetime. key words: optical fiber LAN, protection, reliability, capital expenditures (CAPEX), operational expenditures (OPEX), fiber-to-the-home (FTTH), passive optical network (PON), active optical network (AON)

Impact of Fiber Duplication on Protection Architectures Feasibility for Passive Optical Networks

“…This significantly reduces the effect of fiber cuts or failures [6,7]. Ring topology provides the required reliability at acceptable costs; however, use of the POC between OLT and individual ONU module introduces serious power budget issues, which effects network capacity in terms of the number of subscribers [4,8,9]. Besides the commonly used ring-and tree-based network architectures, hybrid topologies are readily adapted for the implementation of survivable PON at the access domain.…”

“…Therefore, OF paths require more attention as compared to other components of the networks, in order to ensure seamless transmission of information, minimize the loss of data, service interruption penalty cost, and PON downtime per year [4].…”

“…The basic ring-based PON is shown in Figure 3, which contains OLT module at the CO. In order to avoid the high deployment cost of OLT module, this architecture employs a single unit, owing to the fact that failure per year of OLT module is minuscule [4,18]. End-face of the OLT module is connected to a switching arrangement ðSA co Þ that extends the OF medium in both clockwise (CW) and counter clockwise (CCW) directions.…”

“…CAPEX includes the investment utilized for the deployment of PON at access domain and is calculated by computing the cost expenditure on network devices along with the OF infrastructure. OPEX includes the cost incurred on the network operations from the time of deployment till replacement by a new technology [4,15,22,23].…”

Self-Healing Hybrid Protection Architecture for Passive Optical Networks

“…Efficient operation of PONs requires high availability along with fault detection and restoration for smooth transmission of data between OLT and subscriber premises [1][2][3]. Therefore, it is imperative for the network operators to develop simple and efficient protection architecture, which is reliable and economical for the common end user.…”