Prof. Fumiyuki Adachi
Dept. of Communications Engineering, Graduate School of Engineering, Tohoku University, 6-6-05 Aza-Aoba, Aramaki, Aoba-ku, Sendai, 980-8579 Japan
Challenges Toward Spectrum-Energy Efficient Wireless Networks
Abstract: Due to recent rapid penetration of smart phones into our society, broadband wireless services have been getting more and more popular. It is said that the wireless traffic volume has been increasing rapidly by about 2 times per year. Because of limited available bandwidth, the spectrum-efficiency has been the most important concern for the last few decades. The available energy, in particular for battery operated user terminals, is also limited. Therefore, the energy-efficiency has become an important issue. However, the spectrum-efficiency and the energy-efficiency are in a tradeoff relationship. To improve the spectrum-efficiency and energy-efficiency simultaneously, the wireless access network may need a significant restructuring.
One promising solution is an introduction of small-cell structured network. Both spectrum-efficiency and energy-efficiency can simultaneously be improved by adopting the small-cell structure. However, a wide range of user mobility is problematic; frequent handover will happen. Furthermore, traffic density is not necessarily high everywhere. It is wise to keep the cell size the same as macro-cell network while exploiting more the spatial distribution of users. We are recently investigating two-layer virtual macro-cell network (e.g., a combination of small-cells and macro-cells). There are two approaches to implement the small-cell layer: distributed small base stations and distributed antennas.
In this talk, we will overview the wireless evolution, discuss the spectrum-energy efficiency tradeoff. Then, we will introduce the two-layer virtual macro-cell network. Finally, we will discuss about the power on/off management, distributed dynamic channel allocation, and multi-access problems.
Biography: Fumiyuki Adachi received the B.S. and Dr. Eng. degrees in electrical engineering from Tohoku University, Sendai, Japan, in 1973 and 1984, respectively. In April 1973, he joined the Electrical Communications Laboratories of Nippon Telegraph & Telephone Corporation (now NTT) and conducted various researches on digital cellular mobile communications. From July 1992 to December 1999, he was with NTT Mobile Communications Network, Inc. (now NTT DoCoMo, Inc.), where he led a research group on Wideband CDMA for 3G systems. Since January 2000, he has been with Tohoku University, Sendai, Japan, where he is a Professor at the Dept. of Communications Engineering, Graduate School of Engineering. His research interest is in the area of wireless signal processing (multi-access, equalization, antenna diversity, adaptive transmission, channel coding, etc.) and networking.
He is an IEICE Fellow and an IEEE Fellow. He was a recipient of the IEEE Vehicular Technology Society Avant Garde Award 2000, IEICE Achievement Award 2002, Thomson Scientific Research Front Award 2004, Ericsson Telecommunications Award 2008, Telecom System Technology Award 2009, Prime Minister Invention Award 2010, British Royal Academy of Engineering Distinguished Visiting Fellowship 2011, KDDI Foundation Excellent Research Award 2012, VTS Conference Chair Award 2014, and C&C Prize 2014. He is listed in Highly Cited Researchers (http://highlycited.com/isihighlycited.htm#table).
Prof. Werner Prost
University of Duisburg-Essen, Solid-State Electronics Department and CENIDE, Germany
Nanowires for High-Speed Nanoelectronics and Nanophotonics
Abstract: The application of epitaxial compound semiconductor nanowire heterostructures for low-energy, high-speed nanoelectronics and nanophotonics will be presented...
Biography: Werner Prost received the Ph.D. degree in electrical engineering from Duisburg University in 1989. Since then he headed the epitaxial growth lab and the nanoelectronic activities of the Solid-State Electronics Department at the University Duisburg-Essen. His main interest is to contribute to the development of micro-, nano-, and optoelectronic devices for communication technology by means of advanced heterostructure technology. He has (co-) authored more than 160 papers in scientific journals and conference proceedings. Werner Prost contributed to the Center of Excellence SFB 254 and SFB 445 and he coordinated two EU projects on Resonant Tunneling Devices. He is member of DFG priority program FOR 1616 on nanowire optoelectronics, the “German Crystal Growth Association” (DGKK), and overseas member of the technical group on electron devices of the Japanese Institute of Electronics, Information and Communication Engineers.
Prof. Ifiok Otung
University of South Wales
Beyond 5G: New thinking for truly ubiquitous ample-speed wireless communications
Abstract: Growth in demand for communication services has been unrelenting during the past decade, both in terms of the number of users simultaneously requiring service and the high data rate (so called broadband) nature of user applications. For example, during the same period that the Internet grew from a global penetration of 12% in 2003 to 38% in 2013, the number of mobile cellular telephone subscriptions skyrocketed from 22% to 93% of the world’s population. Today’s global communication network, providing reliable error-rare information transmission in a timely fashion, is a hugely commendable feat and the culmination of the work of governments, regulatory bodies, industry, academia and countless individuals over a period of more than 150 years. However, much of the work was unplanned and uncoordinated, and progress was piecemeal and often opportunistic and through trial and error. In particular, no one sat down 100 or 50 years ago and said, “Let us build a global Internet, and here’s the plan.” Furthermore, as evidenced by the evolutionary generations of cellular telephony from 1G in 1981 to 5G by 2020, innovative solutions are often short-sightedly targeted at current challenges rather than bold future aspirations. The short shelf life of ‘innovative’ designs should therefore hardly surprise. This talk envisions a future global communication network that caters to not just our eyes and ears but also our senses of touch and smell, connects people as well as functional things, provides continuous coverage and observation of the entire planet, focuses on ample rather than high speed, and makes sparing and sustainable use of resources. The realisation of this vision requires a host of new sensors and displays, but wireless connectivity capability must be ready for the global data transmission deluge that would ensue. Transmitters (from terrestrial systems to high-altitude platforms and space-orbiting satellites) and nodes that drive this future network will be intelligent link-aware devices capable of leveraging various signal processing strategies to optimally adapt to changing channel and network conditions. We discuss fundamental trade-offs amongst the three primary system resources of bandwidth, signal power and time and identify possible paths to a future-proof truly ubiquitous ample-speed global communication network. Solutions are discussed for densely populated conurbations and for coverage of regions around the North and South Poles that are invisible to geostationary satellites. Ideas and benefits are also presented for a global Earth monitoring constellation system (GEMCoS) that provides full and continuous sub-metre resolution imaging of the entire Earth (land and sea).
Biography: Ifiok Otung was appointed Professor of Satellite Communications at the University of South Wales (USW) in December 2011. He is the author of several textbooks, including the internationally acclaimed 664-page Communication Engineering Principles, ISBN 9780333775226, published in 2001 by Palgrave Macmillan, and the 520-page Digital Communications, ISBN 9781849196116 published in 2014 by the Institution of Engineering and Technology (IET) London. Ifiok heads the Mobile and Satellite Communications Research Group at USW and is Associate Editor of the IET Journal of Engineering. His research experience in the areas of Wireless and Satellite Communications includes supervision of 16 PhD and over 100 MSc projects as well as numerous Journal and Conference publications. Ifiok earned a PhD in Satellite Communications from the University of Surrey in 1995.