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SPEAKER: Dr. Y. Charlie Hu, Ph.D.

Extending the Battery Life of the Billion Smartphones
Monday, February 20, 2017, 10:00 am to 11:00 am

Mobile Enerlytics - Founder and CEO

Purdue University - Professor of Electrical and Computer Engineering
Extending the Battery Life of the Billion Smartphones
Monday, February 20
Dreese 260
10:00 a.m. - 11:00 a.m.

Despite the incredible market penetration of smartphones and exponential growth of the app market, utility of smartphones has been and will remain severely limited by the battery life. As such, energy has increasingly become the scarcest resource on smartphones that critically affects user mobile experience. In this talk, I will start with a first study that characterizes smartphone energy bugs, or eBugs, broadly defined as an error in the smartphone system (apps, framework, OS, hardware) that results in unexpected smartphone battery drainage and leads to significant user frustration. As a first step towards taming energy bugs, we built the first source-code energy profiler, Eprof, that enables energy-efficient app development by answering the very question "where was the energy spent inside the app?". Building Eprof in turn requires designing a fine-grained, online power model that captures the unique asynchronous power behavior of modern smartphones, which defies the power models developed in the past decade.  Using Eprof, we performed the first dissection of the energy drain of some of the most popular apps in Google Play and discovered energy bugs in popular apps like Facebook.
While essential, Eprof only provides a semi-automatic tool for energy debugging. The “holy grail” in energy debugging in smartphones is to develop fully automatic debugging techniques and tools. I will articulate the fate of energy bugs in smartphone apps and operating systems as a consequence of the aggressive energy management policies adopted by mobile OSes, and present several automatic energy bug detection systems we have developed so far.  I will highlight our other work in smartphone energy management as well as some intricacies we learned in transferring the technology to the $100B mobile app industry (by 2020).

Y. Charlie Hu is a Professor of Electrical and Computer Engineering and Computer Science (by courtesy), and an ACM Distinguished Scientist and IEEE Fellow. He received his Ph.D. in Computer Science from Harvard in 1997, and was a research scientist at Rice University and a co-founder of the iMimic Networking, Inc. before joining Purdue in 2002. He is a recipient of the Honda Initiation Grant Award, NSF CAREER Award, Purdue University Faculty Scholar, Early Career Research Award from Purdue College of Engineering, and EuroSys Best Student Paper Award. His research interests include mobile systems, distributed systems, and computer networks.. He most recently served as a general co-chair of ACM SIGCOMM 2014, and PC co-chair of ACM MobiCom 2016 and ACM SIGOPS EuroSys 2018. Since 2010, his group has conducted pioneering work on energy profiling and energy debugging on smartphones which has been widely covered by news media such as ABC News, NBC News, BBC, Times of India, MIT Tech Review, and Scientific American. The technology has been commercialized and is extending the battery life of hundreds of millions of smartphones.