Transparent and autonomous store-carry-forward communication in Delay Tolerant Networks (DTNs)

In sparsely populated mobile ad-hoc networks (MANETs) communication has to cope with mobility and in particular interruptions of connections. The lack of continuous network connectivity is addressed by Delay Tolerant Network (DTN) protocols. DTNs are characterized by varying delays and the fact that a successful delivery of data is not guaranteed. However, today no DTN protocol that functions autonomously and transparently for the application level is available in the related literature. This paper introduces a new approach for store-carry-forward communication in DTNs. In contrast to existing protocols such as the Bundle Protocol, here store-carry-forward communication is supported transparently without the need for application changes. In addition, the decision on whether or not to use store-carry-forward is no longer delegated to user applications. Instead, the decision is taken autonomously by MANET nodes based on the data to be send. The approach requires only local changes on the nodes that are part of the store-carry-forward communication path. Furthermore, it avoids interfering with traditional MANET routing by separating wireless routing from store-carry-forward (DTN) routing. Evaluations using epidemic, history-based and oracle-based DTN routing techniques illustrate successful operation of the introduced approach.