Table of Contents
Advances in Electrical Engineering
Volume 2014, Article ID 261390, 13 pages
Review Article

Caching Eliminates the Wireless Bottleneck in Video Aware Wireless Networks

1Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA
2Intel Corporate Research, 5000 W Chandler Boulevard, Chandler, AZ 85226, USA
3Intel Corporate Research, 2111 NE 25th Avenue, Hillsboro, OR 97124, USA

Received 6 May 2014; Accepted 2 October 2014; Published 30 November 2014

Academic Editor: Dimitrios Axiotis

Copyright © 2014 Andreas F. Molisch et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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.