Video Aware Wireless Networks (VAWN) Research Program

University of Southern California

We investigate fundamentally new cellular architectures to handle the ongoing explosive increase in the demand for video content in wireless mobile environments. We show that distributed caching and collaboration between users and femtocell-like base stations without high-speed backhaul, which we call helpers, can greatly improve throughput without suffering from the backhaul bottleneck problem common to femtocells. We also investigate the role of collaboration among users - a process that can be interpreted as the mobile devices playing the role of helpers also. This approach allows an improvement in the video throughput without deployment of any additional infrastructure. The efficiency of the caching approach depends on two key system properties: (i) the configuration of the "effective" distributed cache, i.e., which user can connect to which helpers and (ii) the popularity distribution of the video files. As a function of these properties, we consider the wireless distributed caching problem, i.e., which files should be cached by which helpers. For the mobiles-as-helpers problem, a key question is the choice of the cluster dimension (collaboration distance), trading off spectral reuse with the probability of finding the desired video within the collaboration distance. Simulations show that our approach can improve the data throughput by as much as 400-500% through addition of helpers, and more than an order of magnitude through the device-to-device communications.

Journal Articles

[J-1] K. Shanmugam and G. Caire, "Wireless Downloading Delay under Proportional Fair Scheduling with Coupled Service and Requests: An Approximated Analysis", journal draft in preparation.

[J-2] N. Golrezai, K. Shanmugam, A. Dimakis, A. F. Molisch, G. Caire, "FemtoCaching: Wireless Video Content Delivery through Distributed Caching Helpers", submitted to IEEE Transactions on Information Theory.

[J-3] N. Golrezaei, A.F. Molisch, A.G. Dimakis, and G. Caire, "Femtocaching and Device-to-Device Collaboration: A New Architecture for Wireless Video Distribution", IEEE Communications Magazine, in press.

Conference Papers

[C-1] N. Golrezai, A. F. Dimakis, and A. F. Molisch, "Device-to-Device Collaboration through Distributed Storage", IEEE Globecom 2012, accpeted.

[C-2] K. Shanmugam and G. Caire, "Wireless Downloading Delay under Proportional Fair Scheduling with Coupled Service and Requests: An Approximated Analysis", Proc. IEEE International Symposium on International Theory (ISIT'12), Boston, MA, USA, July 2012.

[C-3] N. Golrezaei, A.G. Dimakis, and A.F. Molisch, "Wireless Device-to-Device Communications with Distributed Caching", Proc. IEEE International Symposium on International Theory (ISIT'12). Boston, MA, USA, July 2012.

[C-4] N. Golrezai, A. F. Molisch, and A. Dimakis, "Base-Station Assisted Device-to-Device Communications for High-Throughput Wireless Video Networks", Proc. IEEE ICC Workshop on Video-Aware Wireless Networks 2012 (ICC ViOpt'12). Ottawa, Canada, June 2012.

[C-5] N. Golrezai, K. Shanmugam, A. Dimakis, A. F. Molisch, G. Caire, "Wireless Video Content Delivery through Coded Distributed Caching", Proc. IEEE International Conference on Communications (ICC'12), Ottawa, Canada, June 2012.

[C-6] M. J. Neely, A. Saber Tehrani, Z. Zhang, "Dynamic Index Coding for Wireless Broadcast Networks" Off Site Icon, Proc. IEEE International Conference on Computer Communications (INFOCOM'12), Orlando, FL, USA, March 2012.

[C-7] N. Golrezai, K. Shanmugam, A. Dimakis, A. F. Molisch, G. Caire, "FemtoCaching: Wireless Video Content Delivery through Distributed Caching Helpers" Off Site Icon, Proc. IEEE International Conference on Computer Communications (INFOCOM'12), Orlando, FL, USA, March 2012.

[C-8] N. Golrezaei, A.G. Dimakis, A.F. Molisch, and G. Caire, "Wireless video content delivery through distributed caching and peer-to-peer gossiping,"  Off Site Icon Proc. IEEE 45th Asilomar Conference on Signals, Systems and Computers (ASILOMAR'11), pp.1177-1180, Pacific Grove, CA, USA, November 2011.

Technical Reports

[T-1] K. Shanmugam, A. Dimakis and G. Caire, "Index Coding with Side Information Repositories", Technical Report.

[T-2] M. Ji and G. Caire, "Survey of scaling laws for networks with caching nodes", Technical Report.

3. D. Bethanabhotla and G. Caire, "Joint Scheduling and Congestion Control for Adaptive Streaming over Wireless Peer to Peer Networks", Technical Report.