Research On Bundle Protocol Perfomance Of Deep Space Realy Network Based On CFDP

With the dramatic development of terrestrial Internet technology and the increasing complexity of space missions,there is a strong demand for extending the Internet into space and establishing a space information network and providing the technical possibilities of implementation.The future of the deep space information network has several features,such as complex structure,a wide range of communication service types,huge information transmission data volume and high reliability requirements.Therefore the communication protocol must effectively address the long delay,high disconnection rate and low resource problems to achieve real-time sharing of deep space data and comprehensive utilization of resources.In this context,the Delay/Disrupted Tolerant Networks(DTN)came into being.In DTN system,a bundle layer is provided between transmission layer and application layer.The bundle protocol is a protocol developed for the application of bundle layer and is an important part of DTN protocol.It is essential to study this thought of data transmission under this restricted network and link system.In this paper,based on the understanding of the characteristics and requirements of deep space network and combined with the current development of research,we had a comprehensive research of bundle protocol.Based on CFDP,this paper connected the transmission layer and application layer to form the complete protocols.Through the elaboration of the simulation scene and the theoretical foundation,the bundle simulation module is designed,encapsulated and modularized.This paper focused on packet processing and relay nodes and built the network architecture and platform based on bundle protocol to achieve the reliable data transmission and storage and forwarding among three DTN points.In the bundle protocol architecture with CFDP as the transmission protocol,a mathematical model of file transfer delay is established.Then through the platform to simulate the deep space communication,configuration parameters,access to experimental data to verify the validity of the mathematical model.At the same time,this paper had a further detailed analysis for bundle size,transmission interrupt length,data throughput and other related parameters.The paper analyzes the store state of the DTN nodes and the simulation results showed that the changes of the storage space and the release trend.The mode of the storage space are analyzed and judged by the change of the dependent variable such as bundle size and interruption time,etc.The store model of different protocols is compared in detail,while store model of each node is simulated,modeled and compared.Finally,the unified verification of theoretical level and practice level is realized.