Data-Intensive Routing in Delay-Tolerant Networks

Mobile users and wireless devices are now the sources of a large volume of data. In such data-intensive mobile and wireless computing systems, delay-tolerant network (DTN) routing plays a critical role in data routing, dissemination, and collection. In this paper, we tirst introduce a new routing problem in DTNs-data-intensive routing-where data transmitted from one node to another is very large with respect to the size of data which can be transmitted in a single contact and available buffer size at relay nodes. In the proposed opportunistic path model, the contact frequency, contact duration, and buffer constraint are all integrated into a single routing metric. Then, we design the data-intensive routing (DIR) protocol where the path with the highest bottleneck link capacity is defined as the path weight. In addition, we propose the advanced DIR (A-DIR) protocol which focuses on the probability that the last message block will be delivered to its destination within the time constraint. Both the DIR and A-DIR protocols forward messages to better relays or to their destinations based on a greedy strategy with the proposed path metric. Simulations using real mobility traces demonstrate that the proposed DIR and A-DIR protocols achieve their design goals.