Improving energy saving in time-division multiplexing passive optical networks

This article proposes a time-division multiplexing passive optical network (TDM-PON) architecture in which optical network units (ONUs) enter active mode only when the optical line terminal has traffic to deliver. The authors use a hybrid ONU (H-ONU) equipped with a low-cost, low-energy IEEE 802.15.4 module. This module notifies H-ONUs when they should move from sleep to active mode to receive downstream traffic. The authors show that the proposed solution leads to a significant energy saving while satisfying PON delay requirements.