# Advances in Improving Energy Efficiency of Fiber-Wireless Access Networks: A Comprehensive Overview
## 7 Discussion  
The development of new architectures, protocols and algorithms for FiWi networks has been a hot topic in the telecommunications industry in recent years. These networks combine the high speed and reliability of fiber optic cables with the convenience and accessibility of wireless technology, providing a cost-effective solution for delivering broadband services to a wide range of customers. Research on FiWi networking involves the integration of optical fiber and wireless broadband access technologies. FiWi broadband access networks resulting from the integration of optical fiber and wireless technologies can utilize both RoF and R&F hybrid networking technologies. The carbon footprint of ICT infrastructure is gaining increasing public attention and raises concerns related to global warming. This has led to increased research into developing energy-efficient solutions and research dedicated to improving the EE of the FiWi networks is not an exception. The use of fiber optic cables, which transmit data using light signals, allows FWI networks to operate with lower power requirements than traditional copper wire or coaxial cable networks. This not only helps to reduce the energy costs of operating FWI networks, but also has environmental benefits, as it reduces the carbon footprint of telecommunications infrastructure. In addition to the energy-efficient nature of fiber optic cables, FiWi networks can also incorporate other energy-saving technologies. In previous analyses presented for the RoF, R&F, MEC and SDN-based FiWi networks, it has been shown that advanced power-management schemes can be used to dynamically completely or partially turn off components in the FiWi network to reduce the power consumption of certain components when they are not in use. While FiWi networks offer significant energy-saving potential, it is important for telecommunications companies to carefully consider the energy consumption of all aspects of FiWi networks, which includes the wireless components and the fixed network infrastructure required to support them. By adopting energy-efficient technologies and practices, service providers and telecom operators can significantly help to reduce the overall energy consumption of their FiWi networks and contribute to a more sustainable future. Energy efficiency in C-RAN has become an increasingly important topic in recent years as the demand for mobile data services has continually grown. The C-RAN architecture, in which the baseband processing is centralized and the RF processing is distributed, has been proposed as a solution for improving energy efficiency in cellular networks. One of the main benefits of C-RAN is the ability to centralize baseband processing. By centralizing the baseband processing, the power consumption of C-RAN is reduced, since the centralized baseband unit (BBU) can serve more RRUs and thus can be designed to be more energy efficient in comparison with BBUs serving individual RRUs. Centralization also allows for the sharing of resources between BSs, which further contributes to reducing RAN power consumption. Furthermore, the C-RAN enables the dynamic power management of RRUs and BBUs by allowing them to sleep when the traffic is low, and wake up when the traffic demand increases. These BBU and RRU sleeping cycles contribute to the reduction of energy consumption. Additionally, recent research studies proposed a wide range of methods for reducing energy consumption in the C-RAN. These methods include techniques for optimizing the use of resources in the BBUs, strategies for managing the sleep state of the BBUs, resource utilization algorithms for increased energy savings, approaches for associatingBBUs and RRUs, power management algorithms of the RRUs and the use of NFV to execute the functions for improving the EE of BBUs using virtual machines.