Ring Topologies with Energy Efficient Scheduling of ONUs in TWDM PON

The power consumption of ring topologies (both unidirectional and bidirectional) with Time and Wavelength Division Multiplexed Passive Optical Network (TWDM PON) is analyzed in the literature. The Optical Network Unit (ONU), the user device, it is noted that is to be switched ON through the polling cycles. Hence, the polling scheduling algorithm considered for the chosen PON will play a major role in determining the amount of power consumption. Therefore, in this paper, the fixed and Load Adaptive Sequence Arrangement (LASA) polling scheduling algorithms are considered for the adoption of sleep mode for ONU to reduce power consumption in the ring topologies. Through the scheduling algorithms, the provision to transit the ONU to sleep mode is discussed for various network loads observed at the ONUs. A maximum of 18% reduction in power consumption with a fixed polling sequence and 9.27% reduction in power consumption with LASA polling sequence is observed.