VANET stands for "Vehicular Ad-hoc Network". It is a type of mobile ad-hoc network (MANET) that is specially designed for use in vehicles such as cars and buses. In a VANET, vehicles act as network nodes that communicate with each other and with fixed infrastructure such as traffic lights and roadside units. VANETs are designed to support a wide range of applications including security, traffic management, entertainment and infotainment.

The main idea of VANET networks is to enable vehicles to communicate with each other and with the infrastructure in order to improve the safety and efficiency of transport systems. For example, VANETs can be used to exchange information about traffic conditions, road hazards and weather, allowing vehicles to make more informed decisions about speed and route. In addition, VANETs can be used to support a wide variety of safety-critical applications such as forward collision warning, emergency braking, and lane departure warning. VANETs use wireless communications such as WiFi and cellular networks to transmit and receive data, and use routing protocols to ensure reliable and efficient data delivery. They can operate in infrastructure-based, infrastructure-free or hybrid mode and are expected to play a key role in the development of Intelligent Transportation Systems (ITS).

VANET or Vehicular Ad-hoc Network is a type of mobile network designed for use in vehicles. Its purpose is to ensure communication between different neighboring vehicles. According to the IEEE 1471-2000 and ISO/IEC 42010 guidelines, subjects in the VANET network can be divided into three areas:

  1. Mobile domain: This domain consists of two parts. The first is the vehicle domain, which includes all vehicles that are constantly moving, such as buses, cars and trucks. The second part is the domain of mobile devices, which includes all portable devices such as laptops, GPS and smartphones.
  2. Infrastructure domain: This domain also consists of two parts. The road infrastructure domain includes stationary entities on roads such as traffic lights and poles. The central infrastructure domain includes central control centers such as vehicle control centers and traffic control centers.
  3. Domain: This domain includes Internet infrastructure and private infrastructure. The generic domain includes, for example, various nodes and servers and other computing resources that directly or indirectly work for the VANET network.

The mobile domain exchanges information with the infrastructure domain, which processes the data and performs its own modulation. Then, in the second step, the infrastructure domain again communicates with the generic domain and exchanges information with it. This flow of data between stationary and mobile sources results in efficient and effective road use by users. Another form of VANET architecture is the communication architecture, where the types of communication are characterized into four sections, which are:

  1. In-Vehicle Communication: Detects internal system data or vehicle speed and determines factors such as driver fatigue or sleepiness. Determining such factors is critical to public safety as well as driver safety.
  2. Vehicle-to-Vehicle Communication (V2V): Exchange of data between different vehicles to assist the driver by informing each other of warnings and other important information. V2V communication does not rely on fixed infrastructure for data exchange and helps in information dissemination, security and protection applications.
  3. Vehicle-to-road infrastructure (V2I) communication: This communication takes place between mobile vehicles and fixed road infrastructure to collect data. It provides updates related to environmental sensing and monitoring, such as real-time traffic updates or weather updates.

Vehicle-to-broadband cloud (V2B) communication: Allows vehicles to communicate via broadband connections such as 3G/4G. This improves driver assistance and vehicle tracking, as the broadband cloud can contain more traffic information and other data. All the mentioned types of communication take place in one or more VANET networks. The type of communication does not matter, as long as the performance of the VANET does not suffer. As vehicles move and an ad-hoc network is formed, information exchange begins. This transmission of information to other vehicles and nodes happens in one of the ways mentioned. The vehicle operates and uses the VANET network as long as it remains in that network. VANET primarily supports two types of applications: driver assistance and information dissemination. Driver assistance requires the exchange of information that helps the driver maintain a safer and more efficient environment. Information dissemination focuses on providing information to everyone such as drivers, nodes and passengers. Information dissemination applications range from critical security applications to entertainment applications. [G1]

In a VANET, IP (Internet Protocol) protocols play a key role in enabling communication between vehicles and other network entities. VANETs use a specialized version of the IP protocol known as IPv6, which is designed to support a large number of mobile devices and provide better security features. IPv6 in VANETs enables communication between vehicles and other entities such as roadside units, traffic lights, and other connected devices. It enables the exchange of information such as the location, speed and direction of vehicles, as well as traffic conditions and other critical data. In addition, IP protocols in VANETs can also support different types of services such as infotainment, traffic management and emergency services. The use of IP protocols in VANETs is essential for efficient and secure data communication, which is crucial for the safe and efficient operation of connected vehicles.

There are several types of routing protocols that can be used in VANETs, including geolocation-based protocols that use geographic location and network addresses to determine routes; broadcast-based protocols that broadcast data packets to all available nodes on the network; cluster-based protocols that group vehicles with similar characteristics into clusters for local communication; and geo-casting-based protocols that use priority and redirection zones to establish communications within specific regions. In addition, topology-based routing protocols in a VANET rely on the topological structure of the network to determine the best routes for data transmission, such as Zone Routing Protocol (ZRP) and Destination-Sequenced Distance-Vector (DSDV). These protocols have their advantages and disadvantages, such as efficiency in high-mobility environments and scalability, but they can also suffer from problems such as routing loops and slow convergence. [G2]