Novel Sleep Control for EPON Optical Line Terminal Employing Layer-2 Switch Functions

This paper proposes a sleep control function for power saving in the optical line terminal (OLT) of an Ethernet passive optical network (EPON) employing duplicated layer-2 switches (L2SWs). The basic idea is to make one of the duplicated L2SW sleep according to the amount of traffic. Furthermore, this paper proposes a novel sleep control function that uses dynamic bandwidth allocation (DBA) information. The proposed sleep control function calculates the traffic in advance from the DBA information, and switches one of the duplicated L2SW between active and sleep mode based on the accurate traffic predictions. The proposed control function provides exact predictions of the upstream traffic, thus eliminating excess latency due to prediction error. Numerical simulations show the validity of the sleep control proposal.