Energy efficiency of femtocell deployment in combined wireless/optical access networks

Abstract

Optical/wireless convergence has become of particular interest recently because a combined radio wireless and optical wired network has the potential to provide both mobility and high bandwidth in an efficient way. Recent developments of new radio access technologies such as the Long Term Evolution (LTE) and introduction of femtocell base stations open new perspectives in providing broadband services and applications to everyone and everywhere, but the instantaneous quality of radio channel varies in time, space and frequency and radio communication is inherently energy inefficient and susceptible to reflections and interference. On the other hand, optical fiber-based networks do not provide mobility, but they are robust, energy efficient, and able to provide both an almost unlimited bandwidth and high availability.In this paper, we analyze the energy efficiency of combined wireless/optical access networks, in which LTE technology provides ubiquitous broadband Internet access, while optical fiber-based technologies serve as wireless backhaul and offer high-bandwidth wired Internet access to business and residential customers. In this contest, we pay a particular attention to femtocell deployment for increasing both access data rates and area coverage. The paper presents a novel model for evaluating the energy efficiency of combined optical/wireless networks that takes into account the main architectural and implementational aspects of both RF wireless and optical parts of the access network. Several hypothetical network deployment scenarios are defined and used to study effects of femtocell deployment and power saving techniques on network's energy efficiency in urban, suburban and rural areas and for different traffic conditions.

Power Consumption Modeling and Analysis of Integrated Optical-Wireless Access Network

“…Femtocells are small, low power BS typically design for use in a home or small business. It can significantly boost up wireless network capacity [8] and studies in [9] has shown that the deployment of femtocells can significantly increase both access data rates and energy efficiency in areas with high population densities thus making the femtocell as an attractive solution in order to increase network capacity and coverage in an economical way. Trends have shown that traffic from wireless and mobile devices will surpass traffic from wired devices by year 2018 [10].…”

“…In [17], the authors have proposed a centralized scheduling mechanism that shortens the packet delay and the time of transmitting data upon requesting bandwidth. Meanwhile, the work on energy efficiency of the integrated access network can be found in [9], [18], [19]. In [18], the authors discussed the energy efficient bandwidth allocation mechanism that adopts an optical burst switching technique for long reach network.…”

“…Meanwhile, authors in [19] have reported the sleep mode algorithm for energy efficient FiWi networks. In [9], the authors presented the energy efficiency analysis for the integrated optical wireless access networks deploying femtocells. To the best of our knowledge, research on energy efficiency of the integrated access networks generally focus on Layer 2 and 3 solutions.…”

“…We consider femtocell BSs because it is the most energy efficient compared to other type of BSs [9]. Similarly to ONU, the BS can be classified into three basic modules; RF transceiver, DSP/signal processing and interfaces.…”

“…= ⌈ ⌉ (9) where is the network coverage area and is the cell coverage area. Additionally, we assumed that there is no more than one active user within a femtocell at a time.…”