Cache-enabled Small Cell Networks: Modeling and Tradeoffs

TL;DR

This paper models cache-enabled small cell networks using stochastic geometry, deriving formulas for outage probability and delivery rate, and analyzes how system parameters affect performance to guide network deployment.

Contribution

It provides a mathematical framework for analyzing cache-enabled small cell networks, including closed-form expressions for key performance metrics and insights into parameter tradeoffs.

Findings

Outage probability can be reduced by increasing SBS density or cache size.

System performance depends on SINR, cache size, SBS density, and file popularity.

Tradeoffs between infrastructure investment and caching capacity are characterized.

Abstract

We consider a network model where small base stations (SBSs) have caching capabilities as a means to alleviate the backhaul load and satisfy users' demand. The SBSs are stochastically distributed over the plane according to a Poisson point process (PPP), and serve their users either (i) by bringing the content from the Internet through a finite rate backhaul or (ii) by serving them from the local caches. We derive closed-form expressions for the outage probability and the average delivery rate as a function of the signal-to-interference-plus-noise ratio (SINR), SBS density, target file bitrate, storage size, file length and file popularity. We then analyze the impact of key operating parameters on the system performance. It is shown that a certain outage probability can be achieved either by increasing the number of base stations or the total storage size. Our results and analysis provide key insights into the deployment of cache-enabled small cell networks (SCNs), which are seen as a promising solution for future heterogeneous cellular networks.