A development of optical network unit power consumption model considering traffic load effect

Accurate and precise measurement of energy consumption for the deployment of fiber-to-the-home (FTTH) network using Gigabit passive optical network (GPON) is vital to the research community to develop models for the synthesis of energy-efficient protocols and algorithms for the access network. However, lack of power consumption measurement of optical network devices in the past has led to unrealistic and/or oversimplified model being used in simulations. Usually the access network devices are assumed always on and their consumption is both traffic and time independent. Therefore, in this paper we propose an experimentally-driven approach to i) characterize the Optical Network Unit (ONU) from the power consumption standpoint and ii) develop more accurate power consumption model for the ONU. We focus on ONU since it represents the main contributor to the energy consumption of optical access network. The real data in terms of the power consumption and traffic load have been obtained from continuous measurements performed on a GPON network testbed. The measurement is limited to a maximum 100 Mbps data rate due to a limitation in the sampling rate and precision of the measurement device. However, validation has been done with theoretical power consumption model in order to prove the feasibility of the proposed model. Our measurements show that the power consumption of the ONU exhibits a linear dependence on the traffic in which the power consumption at idle mode is 11.51 W while in low power mode the power consumption is around 7.52 W

Power consumption modeling in integrated optical-wireless access network

The access segments of both optical and wireless networks are well known for their domination over the network’s total power consumption. Therefore, the study on energy consumption particularly in integrated optical-wireless access networks is crucial as energy consumption issue is increasingly vital nowadays. Existing works to date largely addressed the physical characteristics of integrated devices and algorithms for layer 2 and layer 3, where the study in power consumption modeling was often ignored. Hence, this thesis focuses on developing a power consumption model for integrated optical-wireless access networks and investigates the energy efficiency of such networks. Gigabit Passive Optical Network (GPON) as the optical backhaul and Worldwide Interoperability Microwave Access (WiMAX) and Long-Term Evolution (LTE) with femtocell application for the wireless network are considered. First, the power consumption model of the integrated network involving Optical Line Terminal (OLT) and integration between Optical Network Unit (ONU) and Base Station (BS) known as Integrated ONU-BS (IOB) are developed. Then, the power consumption behavior of ONU under different traffic loads has been investigated to model the total power consumption of integrated access networks. An empirical approach has been proposed to characterize the power consumption of the ONU by using real GPON testbed and to develop the power consumption model of ONU based on experimental results. This is followed by the extensive analyses that have been conducted to investigate the impact of various parameters such as split ratio, Femtocell Base Station (FBS) cell range, broadcast factor, and modulation and coding scheme into the total network power consumption and energy efficiency. It has been observed that GPONLTE has the worst energy efficiency performance when compared to GPON-WiMAX, even though it offers the highest data rates. The study has been further extended by including energy saving aspects where sleep mode techniques have been applied (i.e. power shedding for the ONU and idle mode procedure for FBS) based on the user behavior from the traffic profile pattern in Cyberjaya municipal broadband access networks. The implementation of energy saving techniques have shown further significant improvement of 15% lower energy consumption for the integrated access network