Modeling of Intermittent Connectivity in Opportunistic Networks: The Case of Vehicular Ad hoc Networks

This chapter analyses connectivity issues in a particular type of opportunistic networks: Vehicular Ad hoc NETworks (VANETs). The features of opportunistic networks well-fit VANETs, characterized by connectivity disruptions occurring due to quick network topology changes, high vehicle speed and variable vehicle densities. VANETs provide both intervehicle and vehicle-to-network-infrastructure communications. Vehicle-to-vehicle communications may not be the most appropriate interconnection scheme for data delivery in sparse or totally disconnected scenarios. Vehicle-to-infrastructure communications represent a viable solution to bridge the inherent network fragmentation that may exist in multi-hop networks formed over moving vehicles, but a ubiquitous roadside infrastructure can incur prohibitive deployment and maintenance costs. In this chapter, we present recent related work focusing on vehicular connectivity models and review hybrid and opportunistic vehicular communication paradigms designed to improve connectivity.