卫星网络中的TCP跨层技术研究  

Research of TCP based on cross⁃layer technology in satellite network

作　　者：张连连 刘锋[1] 孙杰 葛宇 ZHANG Lianlian;LIU Feng;SUN Jie;GE Yu(School of Electronics and Information Engineering,Beihang University,Beijing 100191,China;School of Electrical Engineering,Hebei University of Architecture,Zhangjiakou 075000,China)

机构地区：[1]北京航空航天大学电子信息工程学院,北京100191 [2]河北建筑工程学院电气工程学院,河北张家口075000

出　　处：《现代电子技术》2021年第1期1-4,共4页Modern Electronics Technique

基　　金：张家口市科技局项目(1611067A);河北省科技厅科技支撑计划项目(18274508D)。

摘　　要：CCSDS链路层协议TC的重传功能可以减少误码丢包而导致TCP窗口缩减、吞吐量降低的情况,但是链路层对丢失的数据反复重传易引起数据包端到端传输时延的剧烈变化,可能导致TCP数据包失序和重传定时器发生超时,引起传输层和链路层重复重传的情况。该文通过链路层与传输层的差错控制信息交互,传输层将TCP数据的序列号通告链路层,链路层把重传数据帧信息通告TCP,使TCP能够区分当前的超时与快速重传是否必要,从而减少传输层不必要的重传。仿真结果表明,链路层与传输层的差错信息交互能显著提高TCP在高误码环境下的吞吐量。The retransmission of protocol TC of CCSDS link layer can decrease TCP window reduction and throughput degra⁃dation caused by error code packet loss.However,the repeated retransmission of lost data by the link layer is prone to causing dramatic changes of end⁃to⁃end transmission delay of the data packet,which may lead to disorder of TCP data packet and time⁃out produced by retransmission timer,thereby causing repeated retransmission of transport layer and link layer.By means of the error control information exchange between link layer and transport layer,the transport layer informs the link layer of the serial number of TCP data,and the link layer informs TCP of retransmitted data frame information,so that the TCP can distinguish if the current timeout and fast retransmit are necessary,so as to reduce unnecessary retransmissions performed by the transport lay⁃er.The simulation results show that the error information interaction between link layer and transport layer can significantly im⁃prove the throughput capacity of TCP in environments with high bit error.

关 键 词：TCP 跨层交互 卫星网络 高误码率 信息交互 重传机制 

分 类 号：TN915.04-34[电子电信—通信与信息系统] TP393[电子电信—信息与通信工程]