Cooperative Robust Forwarding Scheme in DTNs using Erasure Coding

In Delay/Disruption Tolerant Networks (DTNs), network connectivity is highly dynamic due to node movements. Several fundamental assumptions of the conventional wireless networks no longer hold in DTNs, which in turn requires new architectures and protocols design. Routing in DTNs is a challenging problem as the mobility pattern and the available resources of each node, such as buffer space, link speed, remaining battery power, etc, could be dramatically different. In this paper, we propose a COoperative Robust forwarding scheme using Erasure coding (CORE) for DTNs. We first introduce a generalized expression for evaluating the capability of a node to deliver a message to its destination. The message forwarding decision is made based on the capability of the encountering nodes to relay the messages. Furthermore, instead of simply duplicating/forwarding the entire message, we adopt erasure coding to generate message redundancy. With a fixed overhead, we can generate a large number of message blocks using erasure coding and forward those message blocks to more relay nodes. Therefore, our proposed message delivery scheme takes advantage of both the cooperation and the diversity of the relay nodes. Extensive simulations show that our proposed scheme, CORE, outperforms several existing protocols.