Load Regulation on Energy Saving Mechanisms of EPON Networks

The Ethernet passive optical network (EPON) is one of the most efficient transmission technologies for broadband access. However, an unregulated transmission could waste energy if an ONU transmits an insufficient or excessive amount of packets in one time cycle on an energy saving EPON network. For an insufficient transmission, it invokes an unnecessary power consumption, since a power saving ONU has to wake up early for transmitting few packets only. For an excessive transmission, it allows an ONU to stay at the active mode for a longer time but to push other ONUs out of transmission cycle. Load regulation enables an energy saving EPON system to provide near constant loading. This paper studies an appropriate threshold for an ONU to switch between active or energy saving modes. Performance results reveal that satisfactory power saving effects can be achieved via proper load regulation applied on both upstream and downstream channels at the cost of the delay performances of low-priority packets.