A dynamic flow model for constrained Delay Tolerant Networks

Due to network partitioning and intermittent connectivity, one of the most challenging problems in Delay-Tolerant Networks (DTNs) is routing. Namely, an efficient routing scheme should deliver messages properly to achieve a high performance, such as delivery ratio and delivery delay, etc. When considering bandwidth and storage constraints, the routing problem becomes more complicated. This paper investigates such routing problem in bandwidth and storage-constrained DTNs. We firstly formulate the problem of routing in constrained DTNs into multi-commodity dynamic flow problem and then propose our routing scheme based on classical algorithm, named as Optimal Global Routing (OGR). Our OGR is finally evaluated on publicly available data trace RollerNet against three other related protocols. The results show that OGR can achieve high performance on delivery ratio, delay and hop.