We propose a power consumption model for the ONU and evaluate the ONU power consumption in various next generation optical access (NGOA) architectures. Further, we study the impact of the power savings of the ONU in various low power modes such as power shedding . With the growing global deployment of Fiber-to-the-Home (FTTH) networks driven by the demand for ensuring high-capacity broadband services, mobile network operators (MNOs) face challenges of excessive energy consumption (EC) of wired optical access networks (OANs). This paper presents a. Abhishek Dixit, Bart Lannoo, Didier Colle, Mario Pickavet, and Piet Demeester The optical network unit (ONU), installed at a customer's premises, accounts for about 60% of power in current fiber-to-the-home (FTTH) networks. The invention relates to an energy saving method of ONU in an XG-PON system or a GPON system. In set time, the PON link of the ONU does not receive down customer data, and no up customer data is sent, the ONU enters deep sleep while sending a DG (dying gasp) message to tell the OLT (Optical Line. The range of communication services can be significantly expanded if an optical network unit (ONU) is driven by laser energy via an optical fiber. One use case in this context is driving an ONU for collecting sensor data from IoT devices in an environment without a power supply (e.