中文摘要：

在TCP Westwood基础上提出了一种适合无线有线混合网络的TCP改进算法——TCP Yolanda，该算法以瓶颈链路缓冲区长度测量值为参数，采用分两个子阶段的方式改进拥塞避免阶段以更有效进行传输控制，使传输过程能更长时间保持在稳定的高速率状态，并能在误码率较高的无线网络环境下快速恢复拥塞窗口大小，另外在传输发生错误时能判断丢包原因并进行区别处理。基于ns2的仿真实验表明，改进后的TCP算法在网络传输吞吐率、传输稳定性等方面的性能有较大提升，并且保持较好的连接公平性和友好性。

英文摘要：

Based on the TCP Westwood, this paper proposes a modified TCP algorithm for wire-wireless hybrid networks, named TCP Yolanda. The algorithm is characterized by the following： according to the measurement values of bottleneck link buffer length, the congestion avoidance phase of TCP is divided into two sub-phases for better control, which keeps TCP connection stable at high speed for a long time. Furthermore, under a higher bit error rate, the cause of packet lost in transmission can be distinguished and proper action can be taken. The simulation results based on ns2 show the algorithm＇ s significant improvements in the performance of network throughput and stability, and its connection fairness and friendliness is also preserved.