%0 Journal Article
%T Caching Eliminates the Wireless Bottleneck in Video Aware Wireless Networks
%A Andreas F. Molisch
%A Giuseppe Caire
%A David Ott
%A Jeffrey R. Foerster
%A Dilip Bethanabhotla
%A Mingyue Ji
%J Advances in Electrical Engineering
%D 2014
%R 10.1155/2014/261390
%X Wireless video is the main driver for rapid growth in cellular data traffic. Traditional methods for network capacity increase are very costly and do not exploit the unique features of video, especially asynchronous content reuse. In this paper we give an overview of our work that proposed and detailed a new transmission paradigm exploiting content reuse and the widespread availability of low-cost storage. Our network structure uses caching in helper stations (femtocaching) and/or devices, combined with highly spectrally efficient short-range communications to deliver video files. For femtocaching, we develop optimum storage schemes and dynamic streaming policies that optimize video quality. For caching on devices, combined with device-to-device (D2D) communications, we show that communications within clusters of mobile stations should be used; the cluster size can be adjusted to optimize the tradeoff between frequency reuse and the probability that a device finds a desired file cached by another device in the same cluster. In many situations the network throughput increases linearly with the number of users, and the tradeoff between throughput and outage is better than in traditional base-station centric systems. Simulation results with realistic numbers of users and channel conditions show that network throughput can be increased by two orders of magnitude compared to conventional schemes. 1. Introduction Demand for video content over wireless networks has grown significantly in recent years and shows no sign of letting up. According to the Cisco Visual Networking Index mobile forecast for 2012¨C2017, mobile video data is expected to grow at a compound annual growth rate of 75 percent to 7.4 exabyes (one million gigabytes) by 2017 [1]. By this time, it is expected to be 66.5 percent of global mobile traffic data (11.2 exabytes), up from 51 percent in 2012. We expect both broadcast and on-demand services will continue to expand, including traditional services like streaming TV content (e.g., sporting events) and newer services like video Twitter, video blogging, cloud-based live video broadcasting, and mobile-to-mobile video conferencing and sharing. Meanwhile, hardware platforms (smart phones, tablets, notebooks, television/set-top boxes, and in-vehicle infotainment systems) continue to push the envelope in performance and graphical quality. More capable processors, better performing graphics, increased storage capacities, and larger displays make devices more powerful and intelligent than ever before. With this increase in device capability comes a
%U http://www.hindawi.com/journals/aee/2014/261390/