报告人：Minghua Chen, The Chinese University of Hong Kong
时间：2015 年 3 月 20 日（周五）上午 9:00-9:55
地点：计算机楼 405
联系人：王新 xinw@fudan.edu.cn
Abstract：
It is a promising vision to utilize white spaces, i.e., vacant VHF and UHF TV channels, to satisfy skyrocketing wireless data demand in both outdoor and indoor scenarios. While most prior works have focused on exploring outdoor white spaces, the indoor story is largely open for investigation. Motivated by this observation and that 70% of the spectrum demand comes from indoor environments, we carry out a comprehensive study of exploring indoor white spaces.
As the first step in exploring indoor white spaces opportunities in metropolises, we first present a large-scale measurement of outdoor and indoor TV spectrum occupancy in 30+ diverse locations in a typical metropolis Hong Kong. Our measurement results confirm abundant white spaces available for exploration in a wide range of areas in metropolises. In particular, more than 50% and 70% of the TV spectrum are white spaces in outdoor and indoor scenarios, respectively. While there are substantially more white spaces in indoor scenarios than in outdoor scenarios, there is no effective solution for identifying indoor white spaces. To fill in this gap, we propose the first system WISER (for White-space Indoor Spectrum EnhanceR) to identify and track indoor white spaces in a building, without requiring user devices to sense the spectrum. We discuss the design space of such systems and jus- tify our design choices using intensive real-world measurements. We design the architecture and algorithms to address the inherent challenges. We build a WISER prototype and carry out real-world experiments to evaluate its performance. Our results show that WISER can identify 30%-50% more indoor white space with negligible false alarms, as compared to alternative baseline approaches.
As a second step, we present WINET (for White-space Indoor NETwork), an indoor multi-AP white space network design framework. We optimize AP placement, spectrum allocation, and AP association. Our design aims at addressing the unique challenges of spectrum fragmentation, spatial variation, and temporal variation in utilizing indoor white space. We build a test-bed and conduct extensive measurements inside an office building across four months to obtain real-world traces. Experimental results show that WINET can increase AP coverage area by an average of 62.2% and obtain 67.9% higher system throughput while achieving fairness among users as compared to alternative approaches.
This is a joint work with Xuhang Yin, Jincheng Zhang, Lichao Yan, and Guanglin Zhang from The Chinese University of Hong Kong, and Ranveer Chandra from Microsoft Research Redmond.
Biography:
Minghua Chen received his B.Eng. and M.S. degrees from the Department of Electronic Engineering at Tsinghua University in 1999 and 2001, respectively. He received his Ph.D. degree from the Department of Electrical Engineering and Computer Sciences at University of California at Berkeley in 2006. He spent one year visiting Microsoft Research Redmond as a Postdoc Researcher. He joined the Department of Information Engineering, the Chinese University of Hong Kong, in 2007, where he currently is an Associate Professor. He received the Eli Jury award from UC Berkeley in 2007 (presented to a graduate student or recent alumnus for outstanding achievement in the area of Systems, Communications, Control, or Signal Processing) and The Chinese University of Hong Kong Young Researcher Award in 2013. He also received several best paper awards, including the IEEE ICME Best Paper Award in 2009, the IEEE Transactions on Multimedia Prize Paper Award in 2009, and the ACM Multimedia Best Paper Award in 2012. He is currently an Associate Editor of the IEEE/ACM Transactions on Networking. His recent research interests include energy systems (e.g., microgrids and energy-efficient data centers), distributed optimization, multimedia networking, wireless networking, network coding, and secure network communications.
