Research On Transmission Protocol Based On DTN In Deep Space Communication

With the development and competition of the world's major powers in the space industry,interplanetary networks(IPN)and deep space communications have gradually become one of the hotspots of future research.This paper studies the Delay/Disruption Tolerant Network(DTN)and LTP(Licklider Transmission Protocol)in the context of deep space communication.Firstly,this paper introduces the bundle layer protocol and convergence layer protocol adopted by DTN to cope with the highly stressed environment of deep space communication,then particularly analyzes the theoretical characteristics and transmission process of LTP protocol.By comparing the three transmission protocols of LTP,TCP(Transmission Control Protocol)and UDP(User Datagram Protocol)from a theoretical perspective,the theoretical basis for the simulation scenario construction and experimental results analysis is laid.Then,Earth-Mars communication is selected as a typical deep space communication scenario to build an experimental platform with a DTN simulator.For the characteristics of the link in this scenario,the DTN with three different transmission protocols based on LTP,TCP,and UDP is simulated by configuring different link time validity and bit error rate.The experimental results show that LTP outperforms the other two protocols in data throughput in deep space communications with large transmission delays.However,affected by the long-term link disruption and high bit error rate,LTP still suffers a significant performance degradation.Finally,in an attempt to improve the performance of LTP under bad channel conditions,the link topology is adjusted by adding one spatial repeater to the simulation scenario.The basic idea is to increase data routing selectivity based on equal link time validity and bit error rate to improve protocol performance.The experimental results show that the proposed method can effectively improve the performance and data throughput of LTP under the same link validity and bit error rate.The experiment indicates that performance of DTN can be improved by optimizing network resource configuration in future IPN.