Stochastic Geometry Analysis of RIS-Assisted Cellular Networks with Reflective Intelligent Surfaces on Roads

TL;DR

This paper models RIS-assisted cellular networks along roads using stochastic geometry, deriving coverage probabilities and demonstrating that strategic RIS deployment significantly improves vehicle user coverage.

Contribution

It introduces a stochastic geometry framework for modeling RIS deployment along roads and derives coverage probability expressions considering network geometry effects.

Findings

RIS deployment increases vehicle coverage in cellular networks.

Network geometry significantly influences coverage probability.

Strategic RIS placement enhances network performance under various conditions.

Abstract

Reconfigurable intelligent surfaces (RISs) provide alternative routes for reflected signals to network users, offering numerous applications. This paper explores an innovative approach of strategically deploying RISs along road areas to leverage various propagation and blockage conditions present in cellular networks with roads. To address the local network geometries shown by such networks, we use a stochastic geometry framework, specifically the Cox point processes, to model the locations of RISs and vehicle users. Then, we define the coverage probability as the chance that either a base station or an RIS is in line of sight (LOS) of the typical user and that the LOS signal has a signal-to-noise ratio (SNR) greater than a threshold. We derive the coverage probability as a function of key parameters such as RIS density and path loss exponent. We observe that the network geometry highly affects the coverage and that the proposed RIS deployment effectively leverages the underlying difference of attenuation and blockage, significantly increasing the coverage of vehicle users in the network. With experimental results addressing the impact of key variables to network performance, this work serves as a versatile tool for designing, analyzing, and optimizing RIS-assisted cellular networks with many vehicles.