Energy-efficiency analysis under QoS constraints using formal methods: A study on EPONs

Abstract

In Ethernet Passive Optical Networks (EPONs), the equipment placed at the customer premises, i.e., the Optical Network Units (ONUs), has been shown to be responsible for almost 65% of the total EPON power consumption. Sleep mechanisms, implemented at ONUs' side, can contribute to the EPONs energy efficiency. However, the trade-off between energy saving and Quality of Service (QoS) requirements should be carefully tuned, especially when the downstream transmission is considered, in order to achieve the desirable results. In this paper, we exploit formal methods in order to build a holistic model representing both the state machine of the ONU in its details as well as the ONU's communication with the Optical Line Terminal (OLT) under EPONs specifications. The quantitative results of our analysis highlight the impact of the non-active periods on the aforementioned trade-off and shows how they can be configured in line with the network parameters.