  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.
