IEEE DISTINGUISHED LECTURER TOUR (DLT)
By Prof. Zhisheng Niu
Electronic Engineering Department, Tsinghua University
Tsinghua National Lab for Information Science and Technology
Talk #1: How much energy can be traded off by how long delay in GREEN communications.
Date : 29th April 2013 (Monday)
Time : 10.00AM – 12.30PM
Venue : Seminar Room, TM R&D, TM Innovation Center, Cyberjaya, Selangor, Malaysia
Talk #2: Rethinking about the Cellular Networks: A Novel Hyper-Cellular Architecture for Green and Smart ICT
Date : 30th April 2013 (Tuesday)
Time : 10.00 – 12.30PM
Venue : Main Meeting Room (Bilik Mesyuarat Utama ), Fakulti Kejuruteraan & Alam Bina (FKAB), Universiti Kebangsaan Malaysia, Bandar Baru Bangi, Selangor
Speaker’s Biography – Zhisheng Niu graduated from Northern Jiaotong University (currently Beijing Jiaotong University), Beijing, China, in 1985, and got his M.E. and D.E. degrees from Toyohashi University of Technology, Toyohashi, Japan, in 1989 and 1992, respectively. After spending two years at Fujitsu Laboratories Ltd., Kawasaki, Japan, he joined with Tsinghua University, Beijing, China, in 1994, where he is now a professor at the Department of Electronic Engineering and the deputy dean of the School of Information Science and Technology. His majorresearch interests include queuing theory, traffic engineering, mobile Internet, radio resource management of wireless networks, and green communication and networks. Dr. Niu has been an active volunteer for various academic societies, including chair of APCC Steering Committee (2003-04), chair of IEICE Beijing Section (2003-07), editor of International Journal of Wireless Networks (2005-09), council member of Chinese Institute of Electronics (2006-11), vice chair of the Information and Communication Network Committee of Chinese Institute of Communications (2008-12), councilor of IEICE-Japan (2009-11), and membership development coordinator of IEEE Region 10 (2009-10). In particular, he has been serving for IEEE Communication Society as chair of Beijing Chapter (2001-08), director of Asia-Pacific Region (2008-09), director for Conference Publications (2010-11), and editor of IEEE Wireless Communication Magazine (2009-12). He has also been serving as general co-chairs of APCC’09/WiCOM’09, TPC co-chairs of APCC’04/ICC’08/WOCC’10/ICCC’12, panel co-chair of WCNC’10, tutorial co-chairs of VTC’10-fall/Globecom’12, and publicity co-chairs of PIMRC’10/WCNC’02. He wasthe guest co-editors of the IEICE Transactions on Communications Special Issue on Advanced Information and Communication Technologies and Services (Oct. 2009), theEURASIP Journal on Wireless Commun. and Networking Special Issue on Wireless Access in Vehicular Environment (WAVE) (2009), the IEEE Wireless Communication Magazine Special Issue on Green Radio Communications and Networks (Oct. 2011), and the Communication Networks Special Issue on Green Communication Networks (to be published in 2012). Prof. Niu received the Best Paper Awards from the 13th and 15th Asia-Pacific Conference on Communication (APCC) in 2007 and 2009, respectively, and Outstanding Young Researcher Award from Natural Science Foundation of China in 2009. He is now the Chief Scientist of the National Fundamental Research Program (so called “973 Project”) of China “Fundamental Research on the Energy and Resource Optimized Hyper-Cellular Mobile Communication System” (2012-2016), which is the first national project green communications in China. He is the fellow of IEEE and IEICE, and a distinguished lecturer of IEEE Communication Society (2012-13).
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Talk #1 – How much energy can be traded off by how long delay in GREEN communications?
One of the key approaches to make the communication networks more GREEN (Globally Resource-optimized and Energy-Efficient Networks) is to have the network architecture and resources more adaptive to the traffic variations, including making some lightly-loaded base stations (BSs) go to sleep. This is the concept of so-called TANGO (Traffic-Aware Network planning and Green Operation) published by the author earlier. To realize this, some delay-insensitive users may have to experience some delay or other kind of QoS degradation when traffic load is high in order to save energy, i.e., energy can be traded off by some delay. The fundamental question then arises: how much energy can be traded off by how long delay?
In this talk, we characterize the tradeoffs between energy consumption and service delay in a base station with sleep mode operations by queueing models. The base station is modeled as an M/G/1 vacation queue with setup and close-down times, where the base station enters sleep mode if no customers arrive during the close-down time after the queue becomes empty and it starts to setup when it sees N arriving customers during its sleep period. Several closed-form formulas are derived to demonstrate the tradeoffs between the energy consumption and the mean delay by changing the close-down time and N. It is shown that the relationship between the energy consumption and the mean delay is linear. Besides, larger N may lead to lower energy consumption, but there exists N that minimizes the mean delay. We also investigate the maximum delay for certain percentage of service, which is closely related to the mean delay. In summary, the closed-form tradeoffs cast light on designing BS sleep control policies which aim to save energy while maintaining acceptable quality of service.
Talk #2 – Rethinking about the Cellular Networks – A Novel Hyper-Cellular Architecture for Green and Smart ICT-
Cellular concept was invented to improve the spectrum efficiency by spectrum reuse and has contributed a lot for the explosive deployment of today’s mobile communication industry. As mobile data and video traffic is fast growing, the next-generation mobile communication (5G?) networks are expected to further provide 10-fold more capacity than 4G mobile networks with the limited spectrum as well as energy resources. To deal with this challenge, the traditional physical- and MAC-layer capacity-enhancement approaches are no more sufficient and efficient. A system- or network-level approach is needed, including rethinking about the existing cellular structure. On the other hand, cellular networks are transforming from just a mobile communication platform to a smart information infrastructure on which more and more always-online type of traffic (e.g., short but frequent signaling packets of various social networks, sensing information of smart earth and smart community, control packets in cooperative heterogeneous wireless networks) need to be handled in an energy-efficient way. As a result, the existing cellular framework should be revisited.
In this talk, we propose a new cellular architecture, named hyper-cellular networks (HCN), aiming at increasing the whole network capacity by more than 10-fold based on the existing limited spectrum and energy resources as well as accommodating ever-increasing always-online traffic in a more energy-efficient way. The key idea here is to separate the coverage of control signals from the coverage of data signals so that the data coverage can be more elastic in accordance with the dynamics of traffic needs and QoS requirements. Some preliminary results have shown that this new paradigm has a great potential in the capacity enhancement and energy saving.