DTN Protocols for Vehicular Networks: An Application Oriented Overview

This survey provides an in-depth analysis of the different proposals for Vehicular Delay Tolerant Networks (VDTNs). We introduce the DTN architecture and classify VDTN proposals according to the type of knowledge needed to route messages. This classification also includes some Delay Tolerant Network (DTN) protocols originally designed for Opportunistic Networks to illustrate the evolution from Opportunistic DTN protocols to VDTN protocols. We also identify a set of common mechanisms that can be applied to almost all the VDTN protocols, heavily influencing their performance. Finally, we present some applications where VDTNs can be applicable and evaluate the suitability of the different proposals for each specific application. Moreover, this survey is not only limited to describing the different protocols but also focuses on the reproducibility and repeatability of experiments. With this in mind, we also review the evaluation methods used by VDTN researchers. We identify a lack of realism in most of the simulation models used by the VDTN research community, providing certain guidelines to address this issue.