Delay tolerant networks (DTNs) make use of opportunistic encounters of nodes for communication. The characteristics of high mobility of nodes, frequent link variation and long communication delays in DTNs result in an absence of an instantaneous end-to-end path from any source to a destination, making routing a challenge in DTNs. To deal with this issue, a lot of routing schemes have been proposed, in which future contacts of nodes are predicted based on node mobility traces and contact information. However, the previous works did not consider the spatial information of nodes, such as dwelling time at a location, and the transitivity of contacts in the prediction process of future encounter opportunities of nodes. In this paper, a novel mobility prediction-based routing (MPR) scheme is proposed for DTNs, in which the spatial information of nodes and contact transitivity are both taken into account. Specifically, a time-homogeneous semi-Markov process model is proposed to describe node mobility. By employing the semi-Markov model, we formulate the probability of a node destined to an area subject to the remaining time period constraint. The simulation results show that the proposed MPR scheme substantially improves delivery ratio and reduces delivery latency compared with traditional DTN routing schemes.
Delay/disruption tolerant networks (DTNs) make opportunistic communications by utilising the mobility of nodes. The characteristics of high mobility of nodes and high dynamicity of network topology result in an absence of instantaneous end-to-end path from any source to a destination and thus make routing a challenge in DTNs. To deal with this issue, researchers have investigated a variety of routing schemes for DTNs based on the prediction of future contacts, in which node mobility is explored and used. However, the previous works did not consider the instant contact information such as the last contact duration time and the instant separation time since the last contact whilst making routing decisions, leading to less prediction accuracy of future contacts and thus worse routing performance. In this paper, a novel contact predictionbased routing scheme is proposed for DTNs to increase delivery ratio by considering the instant contact information. Specifically, to predict the contact probability of two nodes accurately, the statistical contact information, the instant contact information and the contact transitivity are comprehensively considered. The simulation evaluations show that the proposed contact prediction-based routing substantially improves delivery ratio and reduces delivery latency and delivery overhead compared with traditional DTN routing schemes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.