  In recent years, the number of IoT devices has been growing fast which leads
to a challenging task for managing, storing, analyzing, and making decisions
about raw data from different IoT devices, especially for delay-sensitive
applications. In a vehicular network (VANET) environment, the dynamic nature of
vehicles makes the current open research issues even more challenging due to
the frequent topology changes that can lead to disconnections between vehicles.
To this end, a number of research works have been proposed in the context of
cloud and fog computing over the 5G infrastructure. On the other hand, there
are a variety of research proposals that aim to extend the connection time
between vehicles. Vehicular Social Networks (VSNs) have been defined to
decrease the burden of connection time between the vehicles. This survey paper
first provides the necessary background information and definitions about fog,
cloud and related paradigms such as 5G and SDN. Then, it introduces the reader
to Vehicular Social Networks, the different metrics and the main differences
between VSNs and Online Social Networks. Finally, this survey investigates the
related works in the context of VANETs that have demonstrated different
architectures to address the different issues in fog computing. Moreover, it
provides a categorization of the different approaches and discusses the
required metrics in the context of fog and cloud and compares them to Vehicular
social networks. A comparison of the relevant related works is discussed along
with new research challenges and trends in the domain of VSNs and fog
computing.
