Energy versus delay trade-offs in metro-access convergence

Access networks form a large portion of today´s telecom networks. In parallel to their scale, they have high energy consumption. To reduce the energy consumption of access networks, energy saving architectures and protocols have been proposed. Recently, new technologies have emerged for optical access networks such as Long-Reach Passive Optical Networks (LR-PONs) and Fiber-Wireless (FiWi) networks where their convergence offers extended reach and coverage. In this paper, we evaluate packet delay performance and energy-savings in metro-access convergence where Long-Reach EPON (LR-EPON) and Long Term Evolution-Advanced (LTEA) technologies are employed. Through simulations, we show that energy-efficient protocol solutions for the conventional fiber-wireless access networks can still guarantee significant energy savings for a metro-access convergent infrastructure. However, in the extended reach, a trade-off between energy efficiency and delay is observed.