Cheng-Hsin Hsu

Mobile devices are getting increasingly popular all over the world, including developing countries, where mobile users rarely have the Internet access. In this talk, I am going to discuss how to allow mobile users with intermittent network access to access multimedia content. My presentation consists of two parts: (i) offline social network access and (ii) news video distribution over challenged networks. In the first part of my talk, we explore the problem of supporting efficient access to social media contents on social network sites for mobile devices without requiring mobile users to be online all the time. We propose and implement a broker/proxy based architecture that stages data at a broker/proxy, and selectively downloads to the mobile device only those contents that have a high likelihood of being viewed. The system determines the relevance of social media updates that continuously arrive (e.g., Facebook friend updates) for each user. Using knowledge of this relevance and current network/system conditions, we develop scheduling algorithms that determine which social contents are sent to the devices. In the second part of my talk, we propose a Challenged Content Delivery Network (CCDN) to opportunistically distribute news reports to mobile users with intermittent Internet access. In particular, we formulate an optimization problem to compute the distribution plans for individual mobile users, so as to maximize the overall user experience under various resource constraints. Our formulation jointly considers the characteristics of news reports, mobile users, and intermittent networks. We present a distribution planning algorithm based on the multidimensional knapsack problem, and we develop several online heuristics to adapt to the system and network dynamics. We envision that our CCDN will allow news providers to reach out to more mobile users, and mobile users to watch news reports without always-on Internet access.

Cheng-Hsin Hsu received his Ph.D. degree from Simon Fraser University (Canada), M.Eng. degree from University of Maryland (USA), and M.S./B.S. degrees from National Chung-Cheng University (Taiwan). He is an Assistant/Associate Professor at Department of Computer Science in National Tsing Hua University since 2011. Before that, he was a Senior Research Scientist at Deutsche Telekom Lab (California) between 2009 and 2011, a Senior Network Engineer at Motorola Inc. (Illinois) in 2005, and a Member of Technical Staff at Lucent Technologies (Maryland) between 2001 and 2005. He was a Visiting Assistant Researcher at University of California, Irvine and a Visiting Research Consultant at Qatar Computing Research Institute, Doha, Qatar during the Summer breaks in 2013 and 2014, respectively. His research interests are in multimedia networking, mobile computing, and computer networks.