The increasing trend on wireless-connected devices makes opportunistic networking a promising alternative to existing infrastructure-based networks. However, these networks offer no guarantees about connection availability or network topology. The development of  opportunistic applications , i.e., applications running over opportunistic networks, is still in early stages. One of the reasons is a lack of tools to support this process. Indeed, many tools have been introduced to study and characterize opportunistic networks but none of them is focused on helping developers to conceive opportunistic applications. In this paper, we argue that the gap between opportunistic applications development and network characterization can be filled with network emulation. As proof of concept, we propose and describe HINT, a realtime event-driven emulator that allows developers to early test their opportunistic applications prior to deployment. We introduce the architecture and corresponding implementation of our proposal, and conduct a preliminary validation by assessing its scalability.
['Gwilherm Baudic', 'Antoine Auger', 'Victor Ramiro', 'Emmanuel Lochin']
HINT: from network characterization to opportunistic applications