Energy efficiency in next-generation passive optical networks

Abstract

ENERGY EFFICIENCY IN NEXT-GENERATION PASSIVE OPTICAL NETWORKS Author: Raisa Ohana da Costa Hirafuji Supervisor: Divanilson Rodrigo de Sousa Campelo Programa de Pos-graduacao em Engenharia Eletrica Brasilia, November of 2014 Energy efficiency in communication networks has been growing in importance in the last few years, mainly due to economical and environmental issues. Among the existing optical access network technologies, Passive Optical Networks (PONs) are considered the most energy efficient ones. Despite this fact, existing ITU-T PON systems may support two standardized optical network unit (ONU) power saving modes, namely the Doze and Cyclic Sleep modes, which are protocol-based mechanisms for ONU power management. However, notwithstanding that these two modes have been standardized, there is no technical reason to maintain the separation between them. In this master’s work, we present and evaluate the performance of a new and single power management mode for time division multiplexed (TDM) PONs, called the Watchful Sleep mode, which combines the advantages of both Doze and Cyclic Sleep modes into a unique and simpler framework and outperforms them in energy efficiency. Due to its effectiveness, the Watchful Sleep mode has been approved to be included in the ITU-T G.984 (GPON) and ITU-T G.987 (XG-PON) standards. It is also being considered for the NGPON standard (ITU-T G.989), which aims at standardizing TWDM PON networks.