Energy-Efficient DBA and QoS in FiWi Networks Constrained to Metro-Access Convergence

Fiber-Wireless (FiWi) access networks aim at combining the flexibility, ubiquity and mobility of wireless access networks with the robustness and high capacity support of the optical access networks. Several bandwidth allocation algorithms have been proposed for the convergence of fiber and wireless access networks. Besides, fiber-wireless convergence, metro-access convergence and energy-efficiency have appeared as further challenges of the ICTs. In this paper, we report our current research results on the service quality of existing energy-efficient bandwidth allocation schemes in long-reach FiWi networks, in terms of detailed delay performance, fairness and utilization. We show that deployment of energy-efficient Dynamic Bandwidth Allocation (DBA) in a FiWi network does not only guarantee energy savings throughout the day but also introduces reduced maximum packet delay for both FTTX and wireless users, enhanced delay variance for all packets and significant fairness among different parts of the network. Furthermore, energy-efficient DBA decreases average buffer occupancy at the ONUs.