Sleep Buffer-based Cyclic Sleep / Doze model & framework for ITU Next Generation PONs

Abstract

Abstract The power consumption of Next Generation Passive Optical Network (PON) has increased due to the higher number of Optical Network Units (ONU). The International Telecommunication Union (ITU) has provided the options of Cyclic Sleep Mode (CSM) and Cyclic Doze Mode (CDM) schemes for energy conservation. The performance of these low-power modes is critically dependent on traffic arrival rate and traffic threshold on which Local Wakeup Indication (LWI) events are triggered. Therefore, an analytical model of ONU to study different CSM / CDM control schemes is of prime importance. The existing models do not incorporate the sleep buffer which results in limited performance evaluation of the CSM process at low traffic arrival rates and they are unable to possess the CSM / CDM process at higher traffic loads. Therefore, this work improves the existing Discrete-Time Markov Chain (DTMC) based power model by considering a sleep buffer at each ONU to control the local wakeup indication events at the ONU and the Optical Line Terminal (OLT). The proposed model accurately computes the ONU sojourn in each CSM / CDM state, power consumption of ONU, and energy savings as a function of traffic arrival rate. Based on the proposed model a CSM / CDM framework is also added to configure all the parameters efficiently under the given average delay limits.