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

Abstract

SummaryMessage 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.