Resource-efficient routing protocol based on historical encounter time interval in DTN

Delay Tolerant Networks (DTNs) are characterized by the continuously varied network environment and the limitation of resource. To conquer this problem, DTN routing protocols focus on sending multiple copies of data packets to increase the probability of reaching the destination. In addition, nodes in DTN have strong social attributes which affect the performance of networks. However, resource efficiency and social attributes are not the main concern in most of existing DTN routing protocols. In this paper, we present the resource-efficient routing protocol based on historical encounter time interval (RRPHETI). RRPHETI aims at considering the energy and buffer capability when selecting relay nodes and limiting replicas. RRPHETI creates a model to capture the resource consumption behaviors in DTN, and utilizes the maximum likelihood method to estimate the parameters of delivery probability. In particular, RRPHETI exploits historical encounter time interval to measure social relations between nodes, as the more intimate the nodes are, the smaller the encounter time interval becomes. At last, RRPHETI formulates the utility value of a node as a criterion for packet forwarding so as to keep the consistency of direction of packet towards the destination node. The simulation results show that RRPHETI achieves higher delivery ratio and better overhead ratio and average delay with minimal energy consumption compared to other protocols within resource constrained network situations.