A congestion control scheme based on probabilistic packet acceptance and drop in delay‐tolerant networks

Summary Message replication is often used to improve the delivery ratio in delay-tolerant networks because of the short-lived wireless connectivity environment. However, packet replication may easily incur large resource consumption and finally result in network congestion. This paper proposes a probabilistic packet acceptance and drop algorithm (PAD), which adaptively controls congestion for delay-tolerant networks. In PAD algorithm, the queue length and the input/output rate are combined to detect congestion. Based on the congestion state, each node determines the probability of accepting or dropping packets to obtain a good trade-off between high delivery ratio and low overhead. Furthermore, based on the birth–death model, we construct the continuous-time Markov chain to analyze the delivery ratio of a packet. Theory analysis and simulation results show that PAD increases the delivery ratio by more than 130% with least overhead. Meanwhile, it also achieves the shortest average end-to-end delay when the buffer of a node is severely limited. Copyright © 2015 John Wiley & Sons, Ltd.