| dc.description.abstract | In delay-tolerant networks, it is hardly possible to sustain any end-to-end data delivery paths between any two nodes because the networks suffer from various restrictions by non-uniform node distribution, high node mobility as well as limited transmission ranges. Nodes thus take a store-carry-and-forwarding method to send messages to destinations when they have any opportunistic contacts with other nodes in a network. Considering the recent advance of wireless and mobile networking systems, human beings possessing mobile devices are able to store data in such devices, carry the data along with them, and forward the data to encountered devices as encountering people during movement. As human beings appear like mobile nodes in a network context, the scenarios of human movement and contact may fall into the application domain of social-based delay-tolerant networks. Therefore, the research study of human mobility characteristics will contribute to the design of new social-based routing schemes in delay-tolerant network environments.
The study in this thesis investigates lots of related works, including not only delay-tolerant routing but also social-based routing methods for delay-tolerant networks. This literature review finds out several behavior characteristics about human mobility patterns and contacts by social communities. Accordingly, the study exploits these characteristics to design a leverage routing scheme. In this scheme, message forwarding decision is made by referring to the information of contacts between two nodes in the past. To examine the proposed scheme, simulations are conducted to the performance in terms of message delivery probability, overhead ratio, and successful relay ratio. Performance results indicate that the leverage routing scheme not only has better delivery probability but also results in lower amounts of message transmissions in the network. | en_US |