TRANSACTIONS ON EMERGING TELECOMMUNICATIONS TECHNOLOGIES Trans. Emerging Tel. Tech. (2013) Published online in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/ett.2621 RESEARCH ARTICLE Sleep mode management in cellular networks: a traffic based technique enabling energy saving Simone Morosi*, Pierpaolo Piunti and Enrico Del Re Department of Electronic and Telecommunications, University of Florence, via di Santa Marta, 3, I-50139, Florence, Italy ABSTRACT Because of the environmental policies that pursue a significant reduction of global greenhouse gas and to the ambition of the network operators to keep under control operational and maintenance expenditures, energy efficiency has recently become one of the most relevant issues for present and future research activities. This contribution deals with the manage- ment of the base station sleep mode in a cellular network. The forecasting based sleep mode algorithm, justified by daily and weekly periodic behaviour of traffic, is presented and evaluated for general deployments of second and third generation cellular networks. The energy consumption of each base station and the area power consumption are the metrics, which are considered for our simulations. The results show a significant increase of the energy efficiency during low traffic periods with respect to the usual scenario, thanks to the adoption of the proposed strategy. The forecasting based sleep mode algo- rithm has been also compared with a strategy based on real-time measurements and the results show similar performances while the number of updates of the network configuration and the global complexity are decreased. Copyright © 2013 John Wiley & Sons, Ltd. *Correspondence Simone Morosi, Department of Electronic and Telecommunications, University of Florence, via di Santa Marta, 3, I-50139, Florence, Italy. E-mail: simone.morosi@unifi.it Received 4 August 2012; Revised 31 December 2012; Accepted 10 January 2013 1. INTRODUCTION Today, energy saving is one of the main challenges to be faced by actual and future research activities or by life sciences. As a matter of fact, the energy production is responsible for greenhouse gas emissions in the atmo- sphere, which are considered one of the major contributors to the global warming. So, the greater the consumption, the greater the production and, consequently, the greater the emissions. On the other hand, the recent economic crisis and the increase of the price of energy have made the indus- trial companies more sensible to expenditure control and waste avoidance [1]. In this scenario, Information Com- munication Techniques (ICT) can be seen as an enabling technology for a low emission society [2]. Nonetheless, the energetic bill is a very important cost also for ICT companies: in Italy, the energy consumption of the incumbent telecommunication company is respon- sible for the second highest energy bill, the first after the national railway company [3]. In addiction, ICT industry causes about the 2% of global CO 2 emissions: because of the market growth, this contribution is expected to increase in contrast to the new environmental policies of main states [4]. The huge development of ubiquitous applica- tions, the widespread diffusion of smartphones and tablets, the growth of the service data-rates and the even more fre- quent use of the cloud computing paradigm have increased and kept on increasing the traffic request in communica- tions networks: this phenomenon is particularly true for cellular communications whose users are foreseen to be 7600 millions in 2020 with respect to 2950 millions in 2007 [5]. Recent studies [6, 7] highlighted that most of the energy consumption in mobile communications is due to the access network where about 50–60% of global power is spent. Considering negligible the contribution of each single mobile terminal, most of the energy consump- tion of the access network is given by the radio base stations (BSs): as far as these infrastructures are con- cerned, the biggest term is the power amplifier consump- tion, which is about equal to 65%. During the last years, some research projects on energy efficiency in wireless and mobile communications have been funded and launched [8–10]. These projects aim at enabling greener wireless Copyright © 2013 John Wiley & Sons, Ltd.