Description Scalable Advanced Ring-based passive Dense Access Network ArchitectureMain ObjectivesThe intensive use of optical transparency and the latest opto-electronic technologies enables to expand the PON performances and functionality while minimizing the infrastructure requirements at both urban and rural areas Fibre-to-the-Home networks constitute a fundamental segment with the required potential to match the huge capacity of transport networks with the new user communication demands, where deeper research is still to be performed. Network access infrastructure investments are driven by increased number of users requiring broadband access to services enabled by the Internet infrastructure and applications. Fixed access to homes, hotspots, base stations is best served digitally via fibre optic capacity that provides a fundamental boost over the last mile copper solutions. Dense FTTH Passive Optical Networks (PONs) is a cost efficient way to build fibre access and SARDANA is a way to demonstrate how the huge bandwidth available through the fibre access can be exploited in a cost efficient and reliable manner. The key performances that SARDANA project aims at radically improve are the scalability and the robustness, since constitute pillars of such a cost-sensitive segment:o Scalability is reached by means of cascadable remote nodes in a new hybrid architecture, allowing smoothest grow and migration, and the new adoption of remotely-pumped amplification, WDM/TDM overlay, and cascadable remote nodes in a new hybrid architecture, while keeping the passiveness of the PON and reducing civil work investments. o The resulting network is able to serve more than 1000 users with symmetrical several hundred Mbit/s, spread along distances up to 100 km, at 10Gbit/s, in a flexible way, also supporting multi-operator service. o Robustness is achieved by means of the development of new monitoring and electronic compensation strategies over the PON, as well as by the passive central-ring protection.The intensive use of the optical transparency and of the latest opto-electronic technologies enables to expand the PON performances and functionality while minimizing the infrastructure requirements at both urban and rural areas. SARDANA will set an evolutionary path for G/E-PON and incorporate functionalities of metropolitan networks, envisaging access-metro convergence.Technical ApproachThe pursued novel SARDANA network transparently combines the WDM (Wavelength Division Multiplexing) and the TDM (Time Division Multiplexing) dimensions to reach the extra-large user-density. The proposed completely passive resilient FTTH network is based on a WDM ring for the transport of the large amount of downstream and upstream information (up to 1.2Tbit/s if using 64 wavelengths for 2000 users) and TDM trees, transmitting several wavelengths from corresponding operators, sharing a common infrastructure. Passive Remote Nodes (RN), which implement cascadable 2-to-1 fibre optical Add&Drop functions distribute different wavelengths to each of the access trees; remote amplification is introduced at the RN by means of Erbium Doped Fibres (EDFs) to compensate add/drop losses; optical pump for the remote amplification is provided by pumping lasers located at the Central Office (CO), also providing extra Raman gain along the ring. Regarding the digital terminals, the SARDANA project aims at reuse, as much as possible, standard G/E-PON equipment of current and next-generation 10G-versions, performing a quasi-transparent overlay between TDM and WDM layers. The work in SARDANA is organized into several inter-related Work-Packages: 1. WP-Mg: Project Management and Outcomes. 2. WP-Ar: Network Architecture. 3. WP-Mc: MAC and Higher Layers 4. WP-Tr: Transmission and modulation formats.5. WP-Sy: Network Subsystems.6. WP-Im: Monitoring and adaptive compensation of PON Impairments. 7. WP-Dm: Demonstrator and Field-trial.