Vehicular Ad-Hoc Networks in Smart City

Vehicle networks are an emerging technology integrating the latest communication techniques. Each node of the network is a vehicle equipped with one or more wireless radio interfaces. Vehicles communicate with one another thanks to this equipment. A network of vehicles provides, along the route, connectivity to the outside world via gateways to other networks and inter-vehicle communication for intelligent vehicles.

The VANETs are characterized by sporadic connectivity because a vehicle can join or leave a group of vehicles in a very short time due to high node mobility and speed, which leads to having a very dynamic topology.
High Mobility
Several factors can affect mobility in such networks as road infrastructure, for example roads and highways. In addition, mobility in VANETs is directly related to the behavior of drivers and their responses to different and complex encountered obstacles or situations like accidents and traffic jams.
Predictable Mobility
A vehicle is forced to follow the path of the road. This predictable mobility makes it possible to predict the position and the displacement of a vehicle in the future [14].
Frequent Disconnected Network
The density of a vehicle network varies greatly. A high density of vehicles allows the network to be connected, and therefore there is always a path between two nodes that wish to communicate. Conversely, a low density of vehicles results in a high rate of communication disruptions, a longer delivery time if the vehicle keeps the packet, or even the impossibility for two vehicles to communicate.
Energy and Storage Capacity
Contrary to the context of MANETs, where energy constraints represent a challenge for researchers, the elements of the VANET have enough energy that can power the various electronic equipment of a smart car. Thus, the nodes are supposed to have a large capacity for data processing and storage.