A comparison of sleep mode mechanisms for PtP and TDM-PONs

This paper investigates different sleep mode mechanisms in ONUs and OLTs for point-to-point (PtP) optical access networks and time-division multiplexed passive optical networks. In order to identify appropriate sleep mode mechanisms, we consider three factors: (i) packet arrival rates, (ii) packet size as defined by protocols/standards, and (iii) sleep duration. We demonstrate through simulations that in order to achieve greater power savings while satisfying QoS requirements, fixed cyclic-sleep mode is the ideal candidate for all ONUs, whereas dynamic sleep mode and dozing mode can be used for PtP OLTs and TDM-PON OLTs, respectively. Simulation results show that the power consumption per subscriber of PtP and TDM-PON systems can be reduced by up to 42% and 50%, respectively.