Adaptive Forwarding to Match Mobility Characteristics in Delay Tolerant Networks

In this paper, we propose an adaptive and opportunistic forwarding mechanism that is able to match mobility characteristics in Delay Tolerant Networks (DTNs). Our protocol, Seeker, empowers nodes with the ability to estimate future contact opportunities based on a history of pair-wise contacts. Furthermore, Seeker is able to adjust and rewind forwarding and buffering decisions on the fly. This ensures a good trade-off between reliability and resource-efficiency, even when disconnections are frequent and hard to predict. Essentially, the novelties of Seeker are (1) its ability to estimate good relays without having a global network view and (2) its flexibility to operate under different conditions. These features are particularly important as in DTNs, devices are further restricted by strict resource constraints and a contemporaneous path may never exist between two nodes in the network. Using simulations based on a synthetic mobility model and real mobility traces, we show that Seeker is able to adapt its forwarding accordingly in diverse scenarios and achieves high performance with low overhead