Content caching close to the network edge is emerging as one mechanism to help solve the exponential growth in wireless data demand driven by video content downloads. Since it is impossible to cache all content, one needs to design what is stored and where as well as how the unavailable content is efficiently delivered. In this talk we focus on wireless edge-caching architectures and schemes. Our starting point is the observation that wireless network architecture is converging towards a dense deployment of wireless access points (APs) with small coverage combined with cellular base-stations (BS) with larger coverage. The consequence of this heterogeneous architecture is that a user could access the BS as well as multiple APs. Therefore an optimal design is to trade-off the cost (transmission rate) at BS, with caching cost (memory) at APs and access cost (delay) of connecting to multiple APs at the user for a given content popularity profile. We will present caching and delivery algorithms for such architectures and show that these algorithms are (approximately) optimal. The basic idea underlying many of our strategies is inspired by using coded caching and techniques from network information theory. We will examine a separation architecture between the physical layer transmissions and caching and demonstrate its approximate optimality in wireless interference networks. We will also show approximately optimal schemes for non-uniform content popularity as well as adaptive access to content caches. We will examine topologies including broadcast, hierarchical networks and interference networks in some of these results.
This is joint work with Jad Hachem, Nikhil Karamchandani and Urs Niesen.
Suhas N. Diggavi received the B. Tech. degree in electrical engineering from the Indian Institute of Technology, Delhi, India, and the Ph.D. degree in electrical engineering from Stanford University, Stanford, CA, in 1998. After completing his Ph.D., he was a Principal Member Technical Staff in the Information Sciences Center, AT&T Shannon Laboratories, Florham Park, NJ. After that he was on the faculty of the School of Computer and Communication Sciences, EPFL, where he directed the Laboratory for Information and Communication Systems (LICOS). He is currently a Professor, in the Department of Electrical Engineering, at the University of California, Los Angeles, where he directs the Information Theory and Systems laboratory.
His research interests include information theory and its applications to several areas including wireless networks, cyber-physical systems, distributed computation and learning, security and privacy, genomics, data compression; more information can be found at http://licos.ee.ucla.edu. He has received several recognitions for his research including the 2013 IEEE Information Theory Society & Communications Society Joint Paper Award, the 2013 ACM International Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc) best paper award, the 2006 IEEE Donald Fink prize paper award. He served as a Distinguished Lecturer and also currently serves on board of governors for the IEEE Information theory society. He is a Fellow of the IEEE.
He has been an associate editor for IEEE Transactions on Information Theory, ACM/IEEE Transactions on Networking, IEEE Communication Letters, a guest editor for IEEE Selected Topics in Signal Processing and in the program committees of several IEEE conferences. He has also helped organize IEEE and ACM conferences including serving as the Technical Program Co-Chair for 2012 IEEE Information Theory Workshop (ITW), the Technical Program Co-Chair for the 2015 IEEE International Symposium on Information Theory (ISIT) and General co-chair for Mobihoc 2018. He has 8 issued patents.