Vehicular Communications: Survey and Challenges of Channel and Propagation Models

TL;DR

This survey reviews vehicular channel models, classifies them based on mechanisms and usability, and discusses challenges and less-explored environments in vehicular communication modeling.

Contribution

It provides a comprehensive classification of vehicular propagation models and highlights research gaps in environment-specific and vehicle-specific modeling.

Findings

Classified models by propagation mechanisms and implementation approaches.

Analyzed usability factors like complexity and input requirements.

Identified underexplored environments and vehicle types for future research.

Abstract

Vehicular communication is characterized by a dynamic environment, high mobility, and comparatively low antenna heights on the communicating entities (vehicles and roadside units). These characteristics make vehicular propagation and channel modeling particularly challenging. In this article, we classify and describe the most relevant vehicular propagation and channel models, with a particular focus on the usability of the models for the evaluation of protocols and applications. We first classify the models based on the propagation mechanisms they employ and their implementation approach. We also classify the models based on the channel properties they implement and pay special attention to the usability of the models, including the complexity of implementation, scalability, and the input requirements (e.g., geographical data input). We also discuss the less-explored aspects in vehicular channel modeling, including modeling specific environments (e.g., tunnels, overpasses, and parking lots) and types of communicating vehicles (e.g., scooters and public transportation vehicles). We conclude by identifying the underresearched aspects of vehicular propagation and channel modeling that require further modeling and measurement studies.