Energy Management Mechanism for Ethernet Passive Optical Networks (EPONs)

In the past few years, Ethernet Passive Optical Networks (EPONs) have rapidly gained large popularity in broadband access networks. However the current standard has no management protocols aiming at reducing power consumption. In this paper, we propose an Energy Management Mechanism (EMM) within the IEEE 802.3ah control scheme. The main idea is to switch Optical Network Units (ONUs) to sleep mode and determine a suitable wakeup time schedule at the Optical Line Terminal (OLT). In the proposed EMM there is a trade-off between maximizing the power saving and guaranteeing the network performance. We compare two types of downstream scheduling schemes, Upstream Centric Scheduling (UCS) and Downstream Centric Scheduling (DCS), which are different in the way they assign 'active' and 'sleep' states to ONUs. Simulation results in terms of energy consumption and queuing delay are shown for the EMM based EPON system.