vanets

VANETs, or vehicular ad hoc networks, are a form of mobile ad hoc networks in which vehicles equipped with wireless communication devices form a dynamic network to exchange information with other vehicles and with roadside infrastructure. The primary objective is to improve road safety, traffic efficiency, and convenience by enabling low-latency, reliable communication in highly mobile environments.

Typical VANET architecture includes on-board units in vehicles, roadside units at infrastructure sites, and centralized back-end services. Vehicles communicate using V2V (vehicle-to-vehicle) and V2I (vehicle-to-infrastructure) links, collectively referred to as V2X. Short-range, low-latency technologies such as IEEE 802.11p (DSRC) or ITS-G5 are commonly used for direct communications, while cellular-based solutions (C-V2X) built on 4G/5G networks extend range and access to network resources. Messages include cooperative awareness messages (CAMs) and decentralized environmental notification messages (DENMs).

Applications span safety and efficiency: collision avoidance, intersection assistance, emergency vehicle preemption, cooperative adaptive cruise control, traffic signal timing, and congestion management, as well as infotainment and domain-specific services. Architecture supports OBUs in vehicles, RSUs along roads, and back-end systems for data fusion, analytics, and fleet management.

Security and privacy are central concerns. VANETs must provide authentication, integrity, non-repudiation, and privacy protection through mechanisms such as pseudonymous certificates and intrusion detection. Standards and regulatory activity center on IEEE 802.11p/ITS-G5, the IEEE 1609 family, and C-V2X specifications from 3GPP, with ongoing harmonization between regions.

Challenges include highly dynamic topology, reliability and latency requirements for safety messages, scalability in dense traffic, interference and spectrum management, and deployment costs. Research areas cover routing and beaconing, congestion control, secure and privacy-preserving protocols, data fusion, and integration with edge and cloud computing for broader intelligent transportation systems.