Although deployment of fiber to the home (FTTH) systems has been ongoing for over 5 years in certain markets, the industry is still in the early phases of what is expected to be a decades-long optical fiber-based access network build-out. Deployment so far has been largely opportunistic, as in greenfield deployment or copper rehab; competitive, as competitive local exchange carriers (CLECs), utilities, and small multiple systems operators (MSOs) roll out solutions; policy-driven, at the national or municipal level; and strategic, in some isolated cases of a few large carriers. In the coming years as the appetite for bandwidth continues to grow, fiber-based networks will become the only acceptable solution. FTTH technologies have already undergone several stages of evolution, from asynchronous transfer mode passive optical network (APON) to broadband PON (BPON), Ethernet PON (EPON), and Gigabit PON (GPON)-and they will continue to do so in the future. Continuous innovations will allow for a long term increase in bandwidth, an improved cost structure, and greater reach. Starting from current FTTH architectures, including PON, point-to-point (PP), active Ethernet (AE), this paper will focus on the nextgeneration architectures and supporting technologies that will be used in the future including 10 Gbps PON (10GPON), multi-lambda GPON, coarse wavelength division multiplexing (CWDM) PON, and dense WDM (DWDM)-PON. It will show the relative merits of each architecture, the required supporting technologies, and the role of these solutions in the long term evolution of access networks. Β© 2008 Alcatel-Lucent.
the enormous capital costs for civil works and the long construction periods. Compared to the over 300 million digital subscriber line (DSL) lines deployed today, the number of FTTH subscribers is only in the order of 20 million [3], including fiber to the building (FTTBuilding), but this number is destined to see a long and continuous growth.