Cooperative File Sharing in Hybrid Delay Tolerant Networks

Peer-to-peer file sharing techniques are efficient and popular ways to distribute network media contents. Aiming to improve the accessibility of media contents from mobile devices, we introduce peer-to-peer file sharing technique into delay tolerant networks (DTNs), which are formed solely by highly mobile devices and which distribute files utilizing the mobility of humans and vehicles. We first investigate two important implementation issues in a DTN environment: cooperative file discovery and cooperative file download. We then propose several distributed file discovery and file download protocols under different levels of user cooperation. Finally, we conduct extensive simulations using both real and synthetic DTN traces to evaluate the proposed protocols.