Emulation Design And Testbed Implementation Of Multicast Protocols In DTN Networks

DTN network is often in division status and has a great delay, so the traditional Ad Hoc network routing protocols cannot meet the requirements of data transmission in the DTN network. Now the study and result of multicast transmission in DTN scenarios is relatively less, and also these researches using network simulation approach mostly have lower experimental accuracy.This paper researches the design ideas of epidemic routing protocol (EPI), and improves it for supporting the transmission of large files and streaming media. As the generation of multicast services in DTN scenarios, the difficulty of controlling the data copies is also increasing. Ideas based solely on unicast for the improvement of EPI cannot be applied to multicast environment. In this paper, through the method of clustering DTN network,we use MAODV to transmit data in the cluster and EPI to flood data packets between the clusters. Apart from the leader nodes of the clusters need to cache all data packets,there is only one copy of the same data packet in the cluster, so the number of copies in the network is reduced.Emulation combined the network simulation and testbed, not only can simulate the large-scale target network, but also improve the accuracy, so it is an effective method to research network protocol. This paper describes objectives, principles and methods of using QualNet to design emulator.Finally, through outdoor and indoor test-bed scene to verify the designed KMEpid routing protocols, the experimental results show that KMEpid in both scenarios can provide stable delivery rate of more than 90%, and the longer the experimental time is, the higher the delivery rate will be. It is also proved that the protocol can support video transmission by the relative experiments.