Greening next generation optical networks through a collapsed access and metro network architecture

Next generation access networks are leveraging on the efficiency of fiber access networks to deliver higher data rates in a sustainable manner balancing network deployment costs and the network energy footprint. Towards this direction Passive Optical Networks have been attracting a lot of interest since they can deliver an optimal balance of these two critical factors. However, the transition to next generation optical networks is still an issue under research since no mature technology has yet prevailed. Beyond the cost of the equipment that is used to develop the access systems the overall network architecture must be carefully studied and engineered in order to optimize overall system costs, taking power consumption into account. In this paper we demonstrate how a hybrid fiber access network architecture can combine mature TDM PON technologies and WDM multiplexing to exploit the benefits of an ultra long reach access network leading to a collapsed access and metro network architecture. We show that this combination can lead to lower overall power consumption mainly due to efficient traffic aggregation, node consolidation and simplification of metro and core network design.