Performance evaluation of replication-based DTN routing protocols in Intermittently Connected Mobile Networks

Intermittently Connected Mobile Networks (ICMNs) are sparse wireless networks where most of the time an end-to-end path does not exist from source to destination. These networks are characterized by opportunistic connectivity, long and variable delay, asymmetric data rate and high error rate. Hence, they can be appropriately modeled as Delay-Tolerant Networks (DTNs). In this paper, the performance of replication-based DTN routing protocols, namely Epidemic, PRoPHET, MaxProp, RAPID, Binary Spray-and-Wait, and Spray-and-Focus has been investigated in an ICMN scenario against varying message generation rates and number of mobile nodes, respectively. The performance is analyzed on the basis of three metrics: Delivery Probability, Average Latency, and Overhead Ratio. Opportunistic Network Environment (ONE) simulator is used as the simulation tool for evaluating these performance metrics. The outcome of this work shows that for the ICMN scenario and given simulation setting, the best DTN routing technique is Spray-and-Focus, whereas Epidemic routing exhibits the worst performance in terms of all the metrics considered here.