Research of Data Transmission Protocol in Distributed Spaceflight TT&C Network
|School||Shenyang Institute of Aeronautical College|
|Course||Applied Computer Technology|
|Keywords||TT&C Data Trasmission TCP UDP|
The TT&C network that taks on the function of information communication between the spaceflight and the control center is the crucial factor of bringing aerospace mission into effect. And because of the restrict of the fund and the technology, our country can not improve the TT&C network coverage degree very quickly at present. Therefore, a new method, the distributing TT&C network, is put forward to rise our country TT&C network coverage degree in this thesis. But in data transmission, the TCP(Transmission Control Protocol)protocol used on the Internet is confronted with a lot of challenge such as the bigger delay, high bit error rate of chain circuit, the data transmission friendly, fairness and the slow interactive reaction, so it is not suitable to apply to the distributing TT&C network directly.The purpose of this thesis which topic is a part of the distributing TT&C network based on the Internet is to solve the problems of data transmission. Firstly, we discuss the feasibility and the development of the correlative technology support of this thesis. And then, we analyse those questions in data trasmission depending on the require of the TT&C. This thesis shows the improvement algorithms and simulation tests in the following several chapters. The main content of this several chapters are as follows:First, the TCP VegasR algorithm is detailed designed depending on the characteristic specifically of satellite chain circuit and the results is also be studied in contrast to the TCP Vegas algorithm by carrying out simulation. Taking the characteristic specifically of ground chain circuit into account, we mainly describe TCP Reno2 algorithm based on the priori probability of TCP Reno algorithm is designed to avoid some unnecessary fast retransmit in TCP Congestion Control. In this chapter, we descibe the principle and the premise condition of the algorithm and carry out the simulaiton to investigate the result of the algorithm in contrast to the TCP Reno algorithm. In order to reduce the unfairness that the TCP-friendly congestion control brings to itself, the TCP-UDP algorithm is brought forward. Also, we describe the principl of the algorithm and carry out the simulation to investigate the result of the algorithm in contrast to the TCP Reno2 algorithm. Last, the performance of the three algorithms are compared by simulation under a uniform TT&C network environment.When they are in whole network simulation condition, the simulation results indicate that the TCP VegasR algorithm and the TCP Reno2 algorithm are much better, and the TCP-UDP algorithm has a positive value in some extent. so it’s worth to do further research in those research.