Power saving protocol for 10G- EPON systems: A proposal and performance evaluations

Reducing power consumption in access networks has become an increasingly important design goal due to increased concerns for both global warming and network operation costs. Although passive optical networks (PONs) consume the least power among all access network technologies, it is desirable to further reduce PON's power consumption, especially when the line rate is being increased to 10Gbps (10G) and wider deployment is underway. Generally, an effective approach to reduce power consumption is to use sleep-mode operation where functionality is powered off during periods of idleness. This paper therefore proposes a sleep-mode based power saving protocol applied to an optical line terminal (OLT) and optical network units (ONUs) to implement ONU power saving in 10G-Ethernet-PON (10G-EPON) systems. The proposed protocol explicitly distinguishes sleep-, listen-, and awake- states with different power consumption levels. In addition, the paper proposes analytical models for ONU power consumption and response delay to evaluate performance of the proposed power saving protocol. The simulations show that the proposed protocol can significantly improve ONU power saving. The validity of the numerical models is also confirmed by extensive simulations.