Space-Efficient and Dynamic Caching for D2D Networks of Heterogeneous Users

Abstract

Previous approaches to caching for Device-to-Device (D2D) communication cache popular files during off-peak hours. Since the popularity of content may evolve quickly or be unavailable in advance, we propose a flexible approach to cellular device caching where files are cached or uncached dynamically as file popularity evolves Dynamic caching motivates a space-efficient optimization problem Minimum File Placement (MFP), which is to cache a single file in the least amount of cache space to ensure a specified cache hit rate. In order to estimate the future cache hit rate, we use historical heterogeneous contact and request patterns of the devices. We present a bicriteria greedy algorithm for MFP and incorporate this algorithm into a dynamic approach to caching from a library of files with evolving popularity distribution. In an extensive experimental evaluation, we analyze the effectiveness of our approach to mobile device caching and demonstrate its advantages over other static contact-pattern-aware caching and alternative dynamic approaches.