Research On The Construction Of Simulation Platform Based On BP And LTP For Deep Space Communications

With progress of human science and technology,deep space communication has become an important sign that marks the level of national development.There are some notable characteristics of deep space links,such as long delay,intermittent connectivity,high error rate and asymmetry of up/down links.How to satisfy end-to-end Quality of Service requirements and ensure the better quality and efficiency of transmission has become a focus of deep space communication study.Delay/Disrupt Tolerant Network is an effective communication solution for deep space environment.Because of its high costs in satellite level experiments and the lack of flexibility on parameters setting,it is important to build simulation platform for deep space communication protocol verification.So far,all the simulations platforms are mostly based on a single PC or a single module.The system level simulation and link level simulations are separated.It is difficult to simulate the real environment for deep space.We study the DTN protocol structure,and design a simulation platform based on computer network with one computer as a simulation node in deep space simulation.And we have tested the protocol performance on the platform.We conduct a deep learning research on the features of Bundle Protocol(BP)and Licklider Transmission Protocol(LTP).Based on that,we design a simulation platform which can simulate the transmission procedure between the nodes in deep space.We simulate the deep space link by setting limited link bandwidth and transmission delay.At the same time,we use a PC as an error simulation to simulate the dynamic bit error rate in the deep space.In addition,we converge several bundles into a LTP data block to deal with the asymmetric link problem by reducing the number of ACKs on the receiver node.In this paper,we set up a simulation platform which combined system level simulation and link level simulation to simulate the transmission procedure between the real nodes.And we test the performance of BP and LTP comparing with the performance of Transmission Control Protocol(TCP)by the throughout in different BERs.Experimental results show that BP and LTP have an obvious better performance in the case of higher BER.After increasing the transmission distance,TCP has an obvious performance reducing.So BP and LTP are more suitable for the deep space environment than TCP.