Tcp Congestion Control, A Mixed Network Of Technology Research

In recent years, with the rapid development of wireless communication theory and technology, wireless technology is becoming more and more important in the global Internet theory. Mobile host computer and their wireless communications link circuit will turn to be major parts of the future Internet. The computer network, based on the cable, is shifting to a mixing network of wired and wireless.A large number of reliable data service on the Internet use the TCP protocol to transport. TCP has been designed on the wired Internet transport protocols. And its embedded congestion control algorithms can improve network transport efficiency and prevent network from crashing in a traditional wired network. The algorithm premises the reliability of links and network congestion leading to the loss or delay of packets. Because wireless networks have characteristics of higher error rate and serious delay, traditional TCP technology has been unable to adapt to the environment of wired/wireless mixed network. In this case, it is quite significant to have a research on adapting to TCP congestion control mechanisms to get transport efficiency in that mixed environment.This paper offers TCPW optimization algorithm on hybrid network environment after an in-depth study of the TCPW algorithm. It not only improves RTTmin algorithm, but also depending on the network congestion, adjusts bandwidth to enable to estimate bandwidth more accurately and to obtain a more optimal slow-start threshold. In the OPNET simulation software, we build a simulation platform to do a comprehensively simulation analysis on the features and performances of TCPW algorithm and the improved TCPW-M algorithm. The results of the experiment proved that the TCPW-M algorithm has better equity and interoperability of the existing network. Its throughput is higher especially in high BER wireless networks. In addition, TCPW-M just needs to do simple modifications in the sending end of data without modifying the intermediate nodes. Therefore, TCPW-M can be easily installed in the actual network.