Power efficiency of SARDANA and other long-reach optical access networks

Different long-reach optical access networks are studied with respect to their power efficiency. Special focus is dedicated to the hybrid TDM/WDM PON proposed in the SARDANA project, in which remote amplification is utilized for reach extension. The structures of the remote nodes and subsystems for reach extension are shown and discussed. The influence of uplink capacity limitation on power efficiency is evaluated, i.e., the access networks´ efficiencies are presented for different CO capacities in terms of Watt per user and per Gbit/s of user´s bandwidth as a function of number of users connected to the CO. The results show remarkable power efficiency degradation for high-speed access technologies in case of strong uplink limitation, while for unlimited uplink case, 10G-EPON and SARDANA networks show the best efficiency.