In opportunistic networks

nodes form a disconnected network for most of the time due to the nodal mobility

low density

lossy link

etc.Conventional wireless network s protocols are not suitable for intermittently connected networks because they assume that a complete path exists between a source and a destination.This paper presents a novel routing scheme in opportunistic networks called Mail-Relay Transfer Scheme (MRTS)

which includes deploying-phase and transfer-phase.MRTS deploys fixed mail-relay according to collection of historical information by greedy algorithm and judges how to transfer messages according to the meeting probability and remaining storage spaces of nodes.Simulation results show that MRTS can effectively improve message delivery ratio.