Analyzing the Impact of Access Point Density on the Performance of Finite-Area Networks

TL;DR

This paper investigates how access point density affects finite-area network performance, revealing significant differences from infinite-area models and providing accurate approximations for network design and capacity planning.

Contribution

It introduces an accurate approximation method for SINR and user capacity in finite-area networks with fixed APs, highlighting differences from infinite-area assumptions.

Findings

Finite-area networks differ significantly from infinite-area models at low-to-medium AP densities.

The proposed analytic expressions accurately predict system behavior for practical AP densities.

Formulations enable network designers to determine the number of APs needed for target capacity.

Abstract

Assuming a network of infinite extent, several researchers have analyzed small-cell networks using a Poisson point process (PPP) location model, leading to simple analytic expressions. The general assumption has been that these results apply to finite-area networks as well. However, do the results of infinite-area networks apply to finite-area networks? In this paper, we answer this question by obtaining an accurate approximation for the achievable signal-to-interference-plus-noise ratio (SINR) and user capacity in the downlink of a \textit{finite-area} network with \textit{a fixed number of} access points (APs). The APs are uniformly distributed within the area of interest. Our analysis shows that, crucially, the results of infinite-area networks are very different from those for finite-area networks of low-to-medium AP density. Comprehensive simulations are used to illustrate the accuracy of our analysis. For practical values of signal transmit powers and AP densities, the analytic expressions capture the behavior of the system well. As an added benefit, the formulations developed here can be used in parametric studies for network design. Here, the analysis is used to obtain the required number of APs to guarantee a desired target capacity in a finite-area network.