Base-Station Assisted Device-to-Device Communications for High-Throughput Wireless Video Networks

TLDR

The paper proposes a scheme to boost video throughput in cellular networks. The scheme uses device caching of popular videos and device‑to‑device delivery, with a central controller optimizing file placement and collaboration distance to balance frequency reuse and file availability. Even random caching incurs only a minor loss compared to an optimal scheme, and the approach can increase spectral efficiency by one to two orders of magnitude.

Abstract

We propose a new scheme for increasing the throughput of video files in cellular communications systems. This scheme exploits (1) the redundancy of user requests as well as (2) the considerable storage capacity of smartphones and tablets. Users cache popular video files and-after receiving requests from other users-serve these requests via device-to-device localized transmissions. The file placement is optimal when a central control knows a priori the locations of wireless devices when file requests occur. However, even a purely random caching scheme shows only a minor performance loss compared to such a "genie-aided" scheme. We then analyze the optimal collaboration distance, trading off frequency reuse with the probability of finding a requested file within the collaboration distance. We show that an improvement of spectral efficiency of one to two orders of magnitude is possible, even if there is not very high redundancy in video requests.