Minimum makespan workload dissemination in DTNs

This paper poses the following problem: given a task that originates at some node in a Delay Tolerant Network (DTN), how are we to disseminate the workload during pairwise contacts to minimize the makespan? We first investigate the scenario in which each node has access to an oracle that knows global and future knowledge of node mobility, and we propose a centralized polynomial-time optimal algorithm. We then develop a distributed dissemination protocol, D2, which maintains r-hop neighborhood information at individual nodes. D2 makes dissemination decisions based on the estimations of the potential computational capacities and the future workloads of DTN nodes. Using trace-driven simulations, we show that, D2 with only 1-hop information is already near-optimal in a wide variety of environments, and the performance gap becomes smaller as the amount of information maintained at individual nodes increases.