An Overview of Cell Zooming Algorithms and Power Saving Capabilities in Wireless Networks

Cell zooming has emerged as a potential strategy to develop a green communication system in our society and it has become an essential research area of wireless communication. Aiming to highlight the trend of existing cell zooming algorithms and their power saving capabilities, this paper reviews a number of cell zooming algorithms that have been proposed in the literature. Static cell zooming algorithms are effective for off-peak hours and their maximum power saving capability is 50% since off-peak duration is typically not more than 12 hours.Meanwhile dynamic cell zooming algorithms are applicable in full-day operation and they are useful not only for power saving but also for load balancing. However, on/off switching delay, signalling overhead due to traffic information exchange and how to attain information of traffic spatial distribution are existing challenges in dynamic cell zooming algorithms. One noticeable point is that relative power saving in dynamic cell zooming algorithm is less than 50% if traffic spatial distribution is considered. Since location management (LM) was designed for effectively servicing to customers, further researches could lead to work on location management (LM) based cell zooming algorithms for both effective servicing and energy saving

Powering remote area base stations by renewable energy

Abstract. The number of cellular subscriptions have seen a tremendous growth in the last decade and to provide connectivity for everyone has led to growth in number of base stations (BSs). BSs installed at places where reliable grid power is not available has increased and will continue to increase in the coming years to connect everybody on the globe. Energy and cost efficiency is becoming a criterion of ever increasing importance in the information and communication technology sector. Energy and cost efficiency is especially important for remote areas where providing mobile communication services is inhibited by the economic drawback of low revenue potential. In this thesis, we discuss the role of BS power consumption in the cellular networks in order to investigate approaches to lower the overall power consumption of the cellular network. The thesis covers structure of a BS and the power consumption of its components. Previous works and research approaches proposed to reduce the power consumption of BSs and to what extent they can lower the power requirement are discussed. Reducing the BS power consumption will reduce the operating cost for the networks and ease the deployment of BSs in remote areas. Also discussed are the two key technical features of 5th generation cellular access networks (beam forming through massive multiple input multiple output antenna systems and ultra-lean system design) that are promising in terms of reducing the BS power consumption. Furthermore, we discuss viable sources of renewable energy that can be used to power BSs in the remote areas. An overview of the renewable energy resources that can be used for this purpose (solar and wind energy) and their availability in different regions is discussed. The setups for harnessing solar and wind energy to generate power are presented in this thesis. For different cases requirements of wind and solar energy systems to power the BSs are calculated. Results show that while solar energy alone is a feasible option in regions at low latitude, small solar energy systems of 4–7 kW rated output power can easily power BS during the entire year. But in regions of high latitude using solar energy alone cannot meet the BS power requirement as there are long durations of very low or negligible solar irradiation levels. Furthermore, the energy produced by small wind energy setups at different wind speeds is investigated for the purpose of powering BSs. We discuss the range of windspeed levels for which the energy produced is sufficient to power a BS. Areas with average windspeeds of 5–8 m/s are very suitable for using wind energy as a source of power for BSs. Hybrid energy systems to power BSs and also a few energy storage options to store excess power are also discussed in this thesis

On the Minimization of Power Consumption in Base Stations using on/off Power Amplifiers

Most of the work reported in this paper has been carried out while A. Chatzipapas and V. Mancuso were with INRIA Sophia Antipolis, France. A. Chatzipapas was also with Université de Nice Sophia Antipolis, France.International audienceUsing energy generated with fossil fuel causes global warming due to the greenhouse effect, which threatens our environment. One of the challenges for New Generation Networks (NGN) is then the reduction of energy consumption, in particular at the BSs (Base Stations) which use about 85% of the total network energy. We contribute to the research with a mathematical model that calculates the total power consumption of a BS and enlightens the way to minimize it. First, we analyze the power consumed at every different component of the BS. Second, based on the cost incurred in turning off the BS's power amplifiers, we show how to decide whether it is convenient to keep the BS idle during those intervals in which no traffic has to be sent, or to turn off the amplifiers. Our model is evaluated by means of numerical examples, and shows that interesting power gain can be obtained under a large spectrum of load conditions