A Research On Delay Tolerant Network Related Topics

Internet has been a great success at interconnecting homogeneous networks across the globe. The TCP/IP protocol running on the Internet has been the actual standard about network interconnecting. With the development of science and technology and various areas of research more and more new networks began to emerge, such as sensor networks, deep space communication networks, which characterized with high link delays, high link error, often connecting breaking apart, limited nodes resources, they no longer meet some of the basic Internet architecture key assumptions. Interconnecting these new networks with TCP/IP encountered great difficulties. We called the internetworks of these new networks Delay-Tolerant Network (DTN). This thesis analysed the various limitations on TCP/IP to DTN, pointed out that we need a new network architecture different from the Internet, introduced the DTN architecture which the IRTF is researching. The architecture is a store - and-forward model based on message, it uses persistent in-network storage equipment to overcome network connectivity breaking apart. There are a overlay layer—bundle layer inserted between the application layer and the transmission layer. Bundle layer performs routing and forwarding and a number of other functions. This thesis studied the two DTN routing strategy : one is based on a replication; the other is based on knowledge .In the knowledge-based strategy, some specific links metrics based routing algorithms are studied. Under the condition of given some network information, the shortest path algorithms with time-variant cost are considered to solve DTN routing problem. Finally a customized DTN simulator are made to do some simulations, performance of algorithms under various network conditions are compared.