Modeling and Analysis of Content Caching in Wireless Small Cell Networks

TL;DR

This paper models and analyzes content caching in small cell networks, deriving formulas for outage probability and cache hit probability, and optimizing base station density to improve user experience and reduce latency.

Contribution

It provides a novel analytical framework for evaluating cache-enabled small cell networks, including closed-form outage probability and optimal base station density calculations.

Findings

Derived closed-form outage probability as a function of key parameters.

Established the relationship between cache size, base station density, and cache hit probability.

Validated analytical results through simulations.

Abstract

Network densification with small cell base stations is a promising solution to satisfy future data traffic demands. However, increasing small cell base station density alone does not ensure better users quality-of-experience and incurs high operational expenditures. Therefore, content caching on different network elements has been proposed as a mean of offloading he backhaul by caching strategic contents at the network edge, thereby reducing latency. In this paper, we investigate cache-enabled small cells in which we model and characterize the outage probability, defined as the probability of not satisfying users requests over a given coverage area. We analytically derive a closed form expression of the outage probability as a function of signal-to-interference ratio, cache size, small cell base station density and threshold distance. By assuming the distribution of base stations as a Poisson point process, we derive the probability of finding a specific content within a threshold distance and the optimal small cell base station density that achieves a given target cache hit probability. Furthermore, simulation results are performed to validate the analytical model.