A Comprehensive Survey on Connectivity in the Internet of Vehicles: Trends, Architectures, Technologies, and Challenges

Abstract

Due to increasing vehicle density, urbanization, and complex mobility patterns, road traffic injuries continue to pose a serious threat to public health and safety on a global scale. This ongoing crisis highlights the urgent need for intelligent, connected, and proactive vehicular systems that can prevent collisions, reduce injuries, and optimize traffic flow in real-time. The Internet of Vehicles (IoV) has become a key component of next-generation intelligent transportation, enabling seamless communication, data sharing, and collaborative decision-making among vehicles, roadside infrastructure, and cloud services. However, the effectiveness of current IoV communication frameworks in the real world is hampered by issues such as high latency, inefficient bandwidth utilization, limited scalability, and inadequate trust management. To address these challenges, this survey thoroughly examines 50 cutting-edge studies (2021–2025), including V2V (Vehicle-to-Vehicle), V2I (Vehicle-to-Infrastructure), and hybrid V2X (Vehicle-to-Everything) communication, edge–fog–cloud orchestration, 5G/6G integration, SDN (Software Defined Networking)/NFV (Network Function Virtualization) programmability, and security and trust-aware techniques. We provide a structured comparative analysis of communication types, enabling technologies, and limitations. Building on these insights, we propose an adaptive multi-tier IoV connectivity architecture that offers ultra-low latency, high scalability, and robust interoperability through distributed edge–cloud processing, AI-driven resource orchestration, adaptive blockchain-enabled security, and cross-technology communication control. Furthermore, we identify persistent research gaps and outline targeted future directions. The analysis suggests that AI-based optimization combined with hybrid and multi-tier designs has the potential to significantly improve network resilience, adaptability, and efficiency, offering a promising foundation for high-performance, secure, and reliable IoV systems.