Stochastic Analysis of Delay Statistics for Intermittently Connected Vehicular Networks

We analyze information delivery over a network where direct data exchange via wireless is not possible and therefore intermittent connection through vehicular relaying is used. We refer to a multi-hop scenario where a stationary unit exchanges data packets with a destination outside its communication range, using passing-by vehicles as information carriers. In such a context, we propose an exact mathematical model based on Markov chains to quantify relevant performance metrics. In particular, while throughput-related parameters can be directly obtained via queueing analysis, delay statistics are more complex to derive, due to the in-order delivery requirement for the transmitted information content. Hence, data packets transported by fast vehicles still need to wait for the reception of all previous packets, possibly carried by slower vehicles. Nevertheless, by properly exploiting structural properties of the resulting Markov chains, the delay statistics can be fully characterized.