The Network Connection-Based Routing In DTN

The rapid development of network technologies and updating of network equipments result in constant evolution of new network types from the traditional network. Among them, DTN (Delay and Disruption Tolerant Networks) with its peculiar topological properties and excellent adaptability received extensive research and application. DTN is a kind of wireless network composed by self-organized nodes. And in DTN, end-to-end connectivity is intermittent, namely the topology of the network is not stable, the communication state between two nodes can be changed with the mobile nodes'motion. Under this special network structure, dalay of message transmission in this network environment is inevitable. Meanwhile, because nodes'resources and data processing ability are limited, how to transmit the message precisely in the shortest possible time from source node to destination node becomes the focus of DTN research. In DTN, because of the constantly changing connection status of each node resulting from the mobility of the node itself, network segmentation also become one of the key factors which affecting timely and accurately sending message in the network.. How to effectively use all kinds of informations of nodes and the network to forwarding massages is of vital importance in the message transmission process. Aiming at improving the success rate of network message transmission, many innovations and improvements in the aspects of network structure and routing algorithm are proposed. Researchers have done a lot of work in these aspects, and a series of algorithms proposed has made great progress.This paper mainly studies encounter-based message transmission algorithm, namely EBR (Encounter-Based Routing in DTN). On the basis of detailed instructions of the main factors that affecting the network performance and the encounter based routing algorithm, the Improved Network Connection-Based Routing in DTN is proposed. And two improvements aim at message transforming strategy are proposed. In Improved Network Connection-Based Routing in DTN, the link counts and link time are comprehensively considered to make better transmission strategy in order to get better delivery ratio; then, comprehensively considering the link counts and link time to make better transmission strategy in order to get better delivery ratio; lastly, to make good use of the network resources, an acknowledgement mechanism is applied to release storage taken up by useless messages in the network. Simulation results and analysis, confirmed that the former improved methods has definitely made network message transmission performance better. This paper's mainly work are as follows:(1) Analyze the main factors that affecting DTN performance and challenges existing in message transmission in details.(2) Routing strategies based on route prediction to forwarding messages are introduced and analyzed in detail. Then encounter based routing algorithm and its realization are presented.(3) Connection-based routing algorithm in DTN is proposed, and two improvements are presented. Simulation results and analysis, confirmed the effect ion of the proposed improved methods in this article.