Research Of Trust Cooperative Mechanism In Delay Tolerant Network

DTN(Delay Tolerant Network) is a class of distributed self-organizing networks. Packets areforwarded between the nodes in DTN through wireless channel, in which the cooperation takes thekey role. However, due to node’s bandwidth, computing power and energy is limited, some nodes inDTN usually exhibit the character of selfish, discarding the message that should be forwarded bythem. As a result, the performance of the whole network is deteriorated sharply.The uncooperative behavior in the presence of malicious or selfish node in DTN network, andhow to motivate nodes cooperation are studied in this paper. First, this paper models the process ofmessage’s forwarding, and exploits this model to investigate how the node’s uncooperative behavioraffects the performance of DTN, while proving the effectiveness and necessity of cooperationbehavior between nodes. Next, this paper proposes a trust cooperation mechanism based onBayesian inference, which applies direct trust and indirect trust provided by the third partier’srecommendations to quantify node’s cooperative behavior, making the computing of trust valuemore accurately. Finally, by combining trust model with the ant colony bio-inspired algorithm,TrACO(Trust-based Ant Colony Optimization) is proposed to exploits the ant colony algorithm’sability of fast space search and adaptive learning to adapt to the complex and dynamic environmentof the DTN. The simulation results show that the TrACO can achieve acceptable delivery ratio, lowend-to-end delay and low copy number of messages, which demonstrates that it can effectivelyprevent nodes’ selfish behavior.