A novel social contact graph based routing strategy for Delay Tolerant Networks

Delay Tolerant Networks (DTNs) are sparse mobile ad-hoc networks in which there is typically no complete path between the source and the destination. Data routing in DTNs is challenging, and has attracted much attention from the research community. Although many routing schemes have been proposed, they do not address the fairness issue in data delivery to different destination nodes. In this paper, we propose a novel socially-aware routing strategy that optimizes both fairness and throughput. We combine controlled data “spraying” at the source node and single-copy routing at the intermediate nodes. A replication decision is made based on the delivery probability computed over the most probable path in the social contact graph. Furthermore, at intermediate nodes, we sort arriving data into different queues. We then propose a two-level data forwarding strategy that optimizes fairness using round-robin at the first level and throughput using priority scheduling at the second level. Through extensive simulation studies using a real-world mobility trace, we show that our scheme achieves a high delivery ratio, low delay, and low replication overhead.