DTN hybrid networks for vehicular communications

We present an architecture for combining two established network paradigms, IP and Disruption-Tolerant Networking (DTN), into a unified packet gateway design that leverages the advantages of both. Vehicular networking (VNET) scenarios often involve brittle links between communicating nodes due to their mobility. DTN solutions, by using a dynamic hop-by-hop delivery model instead of the end-to-end IP model, are able to sustain a large class of applications despite intermittent links. As a defining characteristic, our design is application-transparent in that it requires no changes to host applications (or the underlying host protocol stacks) in order for them to use DTN transport when IP is not feasible. In addition, we build into the architecture an explicit disruption notification service for keeping users informed as well preventing application time-outs during an IP outage. Finally, given the wide range of behaviors exhibited by applications that can benefit from DTN, our design supports the notion of an application lattice to allow operators to customize, on a per application/group/protocol basis, how the switch between IP and DTN and the disruption notification are performed. A preliminary evaluation based on a C++ proof-of-concept implementation has illustrated several potential benefits of the proposed architecture for VNET applications.