Fading Improves Connectivity in Vehicular Ad-hoc Networks

TL;DR

This paper demonstrates through simulations and analysis that fading channels can enhance connectivity in vehicular ad-hoc networks, challenging traditional assumptions about channel impairments.

Contribution

It provides the first detailed numerical and stochastic analysis showing fading can improve VANET connectivity, offering new insights into channel effects.

Findings

Fading channels increase connectivity probability compared to no-fading models.

Simulation results align with earlier findings in other ad-hoc networks.

Provides an intuitive explanation for the positive impact of fading.

Abstract

Connectivity analysis is a crucial metric for network performance in vehicular ad-hoc networks (VANETs). Although VANET connectivity has been intensively studied and investigated under no-fading channel models for their simplicity, these models do not represent real-world scenarios that suffer channel impairments. The connectivity probability in a multipath propagation environment is too challenging to be caught by a closed formula due to the emerging complexity associated with the randomness in a fading channel. This leads to contradicting statements about the impact of fading on VANET connectivity. In this paper, we numerically estimate the connectivity probability using graph-based Monte-Carlo simulations aiming for better understanding of the connectivity in fading channels. The results show that Rayleigh-fading channels reinforce the connectivity compared to no-fading models at the same level of transmitting power and vehicle densities. While these findings may seem counterintuitive, they agree with similar behavior that was reported earlier in other ad-hoc networks. Using simulations and stochastic analysis, we thoroughly investigate this effect and provide an intuitive interpretation of the positive impact of fading on connectivity.