Providing broadband network access for the customer is the key function of Fiber Access networks. Network is used for connecting Central Office to customer private premises, apartment and office buildings, base stations, and access points. CO is managing the traffic in order to prepare it for further uplink connection to Metropolitan and Transport Networks or routed back to the Access Network.

 

Current Access Networks requirements could be easily met using current solutions, but the main issue is the cost per connected subscriber. Two main types of costs should be considered: OPEX (Operational Expenses) – the costs for maintenance and management of the network and CAPEX (Capital Expenses) – the costs for installation of the network. CAPEX is calculated including inside equipment (OLTs and ONUs) together with outside installation (ducts and optical cables). Note that ducts are being installed between the subscribers with number of optical fiber cable distribution points, that allows bundling optical cables in a shared duct between distribution points and Central Office.

 

All of the expenses should be considered in order to define the requirements for network topology and technology. Main expenses are initial and running cost. Initial cost is summed of material and installation expenses as well as housing. Running costs are the expenses of network maintenance and management, upgrades and powering. In order to design good quality network, one should not forget about performance issues, like QoS, Security, Redundancy, and Safety. In order to simplify network analysis it is suggested to separate the outside plant of the network from the Network elements (Access Nodes, remote Multiplexers, and CPE).

 

In order to get the best transmission/cost ratio, technologies are required to provide compromises. Single medium technologies are less affected by those, but at the expense of higher infrastructure costs.