Design And Development Strategy For Heterogeneous Network Transfer Control

The information age in the future will be formed by the fusion of the wirednetwork, wireless network and other networks, which will become much larger andmore complex. The traditional TCP (Transmission Control Protocol) protocol isdesigned based on a single cable network and significant results are obtained in theoperation of the cable network, but if directly applied in large-scale, complex structureof the heterogeneous network environment, the congestion window value will befrequent halved due to the impaction of the wireless link, causing the loss of networkthroughput which seriously affect network performance. Therefore, how to analyzenetwork conditions and improve network performance in a heterogeneous networkenvironment has important practical significance.According to the problem of declining performance in heterogeneous network ofthe traditional TCP protocol, this paper presented the TCP control strategy based on theanalysis of network transmission performance. Grey correlation method was firstlyselected in the control strategy to analysis the correlation between the round-trip delay(RTT), expected throughput and actual throughput (Diff), short-term throughput (STT)and the network bottleneck link throughput, then fuzzy multi-objective decision-makingmethod was used to quantify network conditions, we could obtain quantitative value ofthe network transmission performance which was named by network transmissionperformance index (TPI). The network conditions can be divided into three levels ofcongestion according to the distribution of TPI at different times. The reasonableness ofthe classification was verified by statisticing the number of3duplicate ACK andtimeout continuously by the sender host. Finally congestion of the network in which thelevel of congestion avoidance phase of the congestion window growth, fast retransmit induplicate ACK number control, and bandwidth estimation method and the steady-statealgorithm to determine the slow start threshold. Create an improved version of the TCPTCP-LO. Simulation results showed that the improved TCP-LO protocol could achievebetter throughput in different BER circumstances, especially in the case of the larger thenetwork load, the network throughput after the usage of the TCP-LO protocol wassignificantly higher than the TCP-Reno protocol. Finally, the TCP-LO algorithm wasfurther validated from two perspectives of fairness and friendliness, the results alsoshowed that the protocol of the TCP-LO could increase network throughput andimprove network performance.