Design and Analysis of Green Optical Line Terminals for TDM Passive Optical Networks

This paper proposes a novel scheme that can efficiently reduce the energy consumption of optical line terminals (OLTs) in time division multiplexing passive optical networks (PONs) such as ethernet PONs and gigabit PONs. Currently, OLTs consume a significant amount of energy in PONs, which is one of the major fiber-to-the-X technologies. To be environmentally friendly, it is desirable to reduce energy consumption of OLTs as much as possible, a requirement that becomes even more urgent as OLTs keep increasing their provisioning data rate; higher data rate provisioning usually implies higher energy consumption. In this paper, we propose a novel energy-efficient OLT structure that guarantees services to end users with the smallest number of power-on OLT line cards. More specifically, we adapt the number of power-on OLT line cards to the real-time incoming traffic. Also, in order to avoid service disruption resulting from powering off OLT line cards, proper optical switches are equipped in OLT to dynamically configure the communications between OLT line cards and optical network units.