Adaptable Quota-stretchy Routing for Delay-tolerant Networks

Delay-tolerant Network is rapidly developed as one of the challenged networks. Currently, only a few studies focus on the flexibility of replicas distribution strategy and the existing routing protocols adapted to changing workload are only qualitatively adjusted. In this paper, we present a novel routing protocol in which the replicas can be both quantitatively and qualitatively adjusted, called Adaptable Quota-Stretchy Routing protocol (AQSR). To let the delivery ratio fall in the pre-set range under constraints of given deadline and limited buffer capacity, this work presents two strategies: 1) adapting the state of message copies to the changing work load; 2) Establish a mechanism to recycle the messages in minor state. Moreover, we propose a buffer management strategy accordingly. Experiment results demonstrate that our protocol has better performance in delivery ratio and network adaptation.