Research Of Routing Algorithms In Delay Tolerant Networks

With the development of network communication technology and the require of various practical applications, it appears some challenging networks that with communication difficult and complicated communication environment. Traditional communication model is not suitable for the special network. Delay tolerant networks (DTN) is exactly under this kind of background to emerge with the tide of the times. It is from the self-organizing wireless network abstracted as a new network model which is widely applied in scenarios like Terrestrial Mobile Network, Underwater acoustic networks, Military Ad-Hoc Network, Sensor Network and so on. It is valuable for both research and practice.Due to the special features of the delay tolerant network, the efficient and reliable routing algorithm design is the key issues of delay tolerant network. This thesis focuses on delay tolerant networking routing problems. At first, this paper introduce the summary, research background, characteristics, system architecture,the application foreground and existing problems in delay tolerant network. Then the typical routing algorithms of wireless sensor network is analyzed. Afterwards, we give the depth research on the issue of delay tolerant network routing problem based on the existing research.Based on the Message Ferrying, we propose an adaptive Ferry routing algorithm combining with the MobySpace concept that proposed by Jeremie Leguay. The algorithm uses the characteristic that MobySpace is by means of the probability to reflect the move features of the node in the physical space, which render the Ferry to select the appropriate way-points to determine their own traverse route according to the probability of nodes in the mobile space. It can ensure Ferry contact a node with an optimal probability to minimum the successive interval node-Ferry contacts. As nodes moving, Ferry always choose the way-points that is suitable for the changes of the network, so it can improve the network performance.Additionally this thesis studies clustered DTN routing problem, proposes a hybrid routing in clustered DTN with Message Ferrying. In this special environment, our routing approach combines DTN routing with the mobile ad-hoc network routing through the use of gateway nodes which in every cluster. Within each cluster, we can use minimal modificated mobile ad-hoc network routing algorithm, and use the Ferry relaying messages between the various clusters to provide a regular link. The hybrid mechanism does not require collaboration between Ferry and other nodes in the nework, which reduces the interference caused by multi-hop transmission and the data exchange over the wireless link interference. Aslo the simulation results demonstrate the effectiveness of the routing mechanism.