Cache-enabled small cell networks: modeling and tradeoffs

TLDR

The study proposes a network model in which small base stations with caching capabilities reduce backhaul load and meet user demand. SBSs are modeled as a Poisson point process, serving users either via finite‑rate backhaul or local caches, and the authors analyze how key operating parameters affect system performance. Closed‑form expressions for outage probability and average delivery rate are derived, showing that desired outage levels can be achieved by increasing SBS density or storage size, and the analysis offers key deployment insights for cache‑enabled small‑cell networks.

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.