A Low-complexity Practical Energy Saving
Algorithm for Real Dense Wireless Scenario
Fei Ding* **, Ye Wang***, En Tong***, Zhi-wen Pan**, Xiao-hu You***School of Internet of Things, Nanjing University of Posts and Telecommunications, Nanjing, China**School of Information Science and Engineering, Southeast University, Nanjing, China***Research and Development Center, China Mobile Group Jiangsu Co.,Ltd, Nanjing, China
dingfei@njupt.edu.cn; { wangyesgs, tonge} @js.chinamobile.com; { pzw, xhyu}@ seu.edu.cn

Abstract—In this paper, a low-complexity practical energy saving algorithm by switching off/on some eNBs in a real dense urban
scenario considering historical and real-time eNB load is proposed. First, eNBs are ranked according to their loads in an ascendingorder and the first eNB in the list with load decreasing and smaller than a low threshold is pre-selected as target switching off cell.
Then, the effect of the target switching off eNB on neighbour eNBs is evaluated. The target eNB switches-off while the load ofneighbour eNBs after the eNB switches off is smaller than another threshold. Since estimation of the additional load on the neighbour
eNBs due to the switch-off eNB is of high complexity, a fast estimation algorithm considering the whole eNB load by a traffic load
conversion coefficient is proposed. The traffic load conversion coefficient declines slowly with the increasing of site traffic load. Third,
the switching-off eNB can be switched on by the active eNBs in a distributed way. Based on the load changes in a week period of theeNB, the cumulative probability distribution of normalized load is analyzed, and then the threshold value of the eNB in different
periods is evaluated. The energy saving ratio is obviously related with the interval between the switched on or off threshold values
and the complexity of the algorithm is significantly reduced. Simulation results show that the proposed energy saving scheme cansave up to 24% energy consumption and with low system complexity.
Keyword—energy saving, practical, energy efficiency, switch off/on
Ding Fei was born in Taizhou city, China, on August 30, 1981. He received the Ph.D. degree in the School of Instrument Science andEngineering, Southeast University, China in 2010. He was an Internet of Things (IoTs) research leader in the R&D Center, China
Mobile Group Jiangsu Co., Ltd., China. He is currently an associate professor in the School of Internet of Things, Nanjing University ofPosts and Telecommunications, Nanjing 210003, China, and also a Research Fellow in the School of Information Science andEngineering, Southeast University. He has long been engaged in wireless networks, Internet of Things (IoTs) and mobilecommunication related key technologies, chaired or participated more than 10 National or Provincial Science and Technology Projects,and chaired more than 20 Enterprise Projects.

Wang Ye was born in Yangzhou city, China, on January 3, 1987. He received the Ph.D. degree in Nanjing University of Posts andTelecommunications, China, in 2013. He is currently an Internet of things (IoTs) and mobile network Researcher in the R&D Center,
China Mobile Group Jiangsu Co.,Ltd, Nanjing, China. His research interests include the internet of things, mobile communication andkey techniques for integrated application between mobile communication and the internet of things.

Tong En was born in Yangzhou city, China, on March 15, 1971. He received Ph.D degree in School of Information Science andEngineering, Southeast University, Nanjing, China. He is currently a Research Manager of the R&D center at China Mobile Group
Jiangsu Co.,Ltd, Nanjing, China. He has long been engaged in the research of mobile communication and the internet of things (IoTs)
related technologies, chaired or participated more than 50 mobile communication research projects. He was the winner of China Mobile
innovation awards for many times and published nearly 20 academic papers.

Pan Zhiwen was born in 1970.11. He received Ph.D degree in Nanjing University, Nanjing, China. He has been with National Mobile
Communications Research Laboratory, Southeast University as associate professor from 2000 and professor after 2004. During 2000
through 2001, he has been involved in the research and standardization of 3G, and from 2002, he has been involved in the investigations
on key technologies for IMT-A and 5G. He has published over thirty papers recently, and holds over 50 patents. His research interests
include self-organizing networks, wireless networking, and radio transmission technology for wireless communications.

You Xiaohu was born in 1962.8. Since 1990, he has been working with National Mobile Communications Research Laboratory atSoutheast University, where he held the rank of professor, the Chair Professor of Cheung Kong Scholars Program and served as Directorof the laboratory. His research interests include mobile communication systems, signal processing and its applications. He has
contributed over 50 IEEE journal papers and 2 books in the areas of adaptive signal processing, neural networks and their applications
to communication systems, and holds over 80 patents. He was the Premier Foundation Investigator of the China National Science
Foundation. From 1999 to 2002, he was the Principal Expert of the C3G Project, responsible for organizing China’s 3G MobileCommunications R&D Activities. From 2001-2006, he was the Principal Expert of the national 863 FuTURE Project. He has been
Section Chair of IEEE Nanjing Section since 2010 and IEEE Fellow since 2011. He served as the general co-chair of IEEE WCNC 2014.
His current research interests focus on wireless and mobile communication systems and modern digital signal processing.