| Abstract: |
A significant portion of today’s network traffic is due to recurring downloads of popular content (e.g., movies, video clips and daily news). It has been observed that replicating the latter in caches installed at the network edge -close to the users- can drastically reduces network bandwidth usage and improve content access delay. The key technical issues in emergent caching architectures relate to the following questions: where to install caches, what content and for how long to cache, and how to manage the routing of content within the network. In this talk, an overview of caching is provided, starting with generic architectures that can be applied to different networking environments, and moving to emerging architectures that enable caching in wireless networks (e.g., at cellular base stations and WiFi access points). Novel challenges arise in the latter due to the inadequacy of wireless resources and their broadcast nature, the frequent hand-offs between different cells for mobile users, as well as the specific requirements of different types of user applications, such as video streaming. We will present our recent results on innovative caching approaches that (i) harvest idle user-owned cache space and bandwidth, (ii) leverage the broadcast nature of the wireless medium to serve concurrent requests for content (iii) exploit the regularity of user mobility patterns, and (iv) apply advanced video encoding techniques to support multiple video qualities (e.g., screen sizes, frame rates, or signal-to-noise ratio (SNR) qualities). These are cutting-edge approaches that can achieve significant performance and cost-reduction benefits over the state-of-the-art methods. |
| Biography: |
Leandros Tassiulas is the John C. Malone Professor of Electrical Engineering at Yale University. His research interests are in the field of computer and communication networks with emphasis on fundamental mathematical models and algorithms of complex networks, architectures and protocols of wireless systems, sensor networks, novel internet architectures and experimental platforms for network research. His most notable contributions include the max-weight scheduling algorithm and the back-pressure network control policy, opportunistic scheduling in wireless, the maximum lifetime approach for wireless network energy management, and the consideration of joint access control and antenna transmission management in multiple antenna wireless systems. Dr. Tassiulas is a Fellow of IEEE (2007). His research has been recognized by several awards including the IEEE Koji Kobayashi computer and communications award 2016, the inaugural INFOCOM 2007 Achievement Award “for fundamental contributions to resource allocation in communication networks,” the INFOCOM 1994 best paper award, a National Science Foundation (NSF) Research Initiation Award (1992), an NSF CAREER Award (1995), an Office of Naval Research Young Investigator Award (1997) and a Bodossaki Foundation award (1999). He holds a Ph.D. in Electrical Engineering from the University of Maryland, College Park (1991). He has held faculty positions at Polytechnic University, New York, University of Maryland, College Park, and University of Thessaly, Greece. |
