Modeling of mobility and groups in inter-vehicular MANET-based networks

This paper evaluates the behavior of mobile ad hoc networks when group mobility is involved. We concentrate on group mobility because road vehicles tend to form groups or fleets whose behavior depends on the behavior of the close-by vehicles. We propose four different group mobility models and present a mobility pattern generator, called grcmob that we designed to be used with the ns-2 simulator. We evaluate the performance of vehicular ad hoc networks under a wide number of scenarios using both TCP and UDP data traffic. We show that the number of groups is more important than the number of nodes and that the impact of area size is almost negligible. We also reveal that the mixture of inter- and intra-group communications has the strongest impact on performance. Finally, we show that the presence of groups forces the network topology to be more sparse and therefore the probability of network partitions and node disconnections grows, affecting performance especially as inter-group traffic increases