A Novel Congestion Control Technique in Delay Tolerant Networks

Abstract

Delay Tolerant Networks (DTNs) are characterized by the lack of contemporaneous paths between any source and destination node. As a basic forwarding strategy, nodes may flood their bundles to every encountered node. This results in congestion and unnecessarily consumes precious network resources. Another strategy is to take advantage of quota based protocols in which only a limited number of copies or replicas are disseminated throughout the network in order to reduce resource usage. However, they suffer from low delivery ratios as their dissemination rate is low. In this paper, the authors propose an Adaptive Message Replication Technique (AMRT) that is fit onto quota protocols to intelligently limit the number of replicas for each generated message. In other words, a source node under AMRT considers the congestion exist amongst the neighbours in order to generate a proper number of replicas for the generated messages. The simulation studies show that when AMRT is applied onto the quota protocols namely, SprayAndWait, EBR, and DBRP, the network performance such as delivery ratio and delay is improved.