| Abstract
The topic for this paper is the efficient data delivery mechanisms in sparse and dynamic network topologies. Specifically, we will present routing algorithms and results of performance analysis for a class of networks that is distinctly different from the traditional IP-based networks. The class of networks under consideration has been referred to as delay tolerant or disruption tolerant networks (DTNs), dynamic networks, or sparse networks. As network technologies have evolved over the years, many non-traditional networks have been developed – wireless sensor and mobile ad hoc networks are examples of such networks. Reliance on infrastructure-based networking seems to be slowly eroding as we discover potential uses for these self-configuring networks. Potential applications range from military combat situations to civilian applications of vehicle-based mobile data centers; disaster relief situations to a commuter bus moving through rural areas providing connectivity by acting as a store and forward switch.
Some unique challenges arise as we move away from the underlying assumptions for traditional IP-based networks. Intermittent connectivity in a DTN makes it difficult to guarantee an end-to-end path for an ongoing data transfer and long round trip delays make it impossible to provide acknowledgements and retransmissions. The proposed DTN architecture offers a set of choices to counter these challenges: messages versus stream of packets; hop-by-hop delivery with optional in-network storage versus end-to-end routing.
In this paper, we present an efficient routing algorithm that takes into consideration the special characteristics of DTNs. The proposed topologies depict intermittent link connectivity, and in general, a disconnected network with limited storage on intermediate nodes. With these constraints, we build our framework to design, develop, and evaluate routing algorithms seeking to minimize delivery time of a message between nodes of the network. The work presented in this pape |