异构网络丢包区分与拥塞控制方法分析-信号与信息处理专业论文.docx

AbstractWith the rapid development of communication technology and Internet, wireless network has become an important part of globlal communication system. Next Generation Network(NGN) certainly will be a single logical overlay network composed of many heterogeneous networks with complex implementation. However, traditional transmission control mechanism simply contributes all loss events to network congestion and blindly takes control strategy, that impact its performance dramatically in wired-wireless heterogeneous networks due to its complicated loss reason.This paper focuses on improving performance of multimedia transmission control in wired-wireless heterogeneous networks based on Loss Differentiation Algorithm(LDA). The main contents of the study are summarized as follows:First, general strategy to solve the problem is summarized in this paper, and typical methods of distinguishing the reasons for packet loss are analysed, classified, and compared, which provides a good basis for further study.Second, this paper puts its emphasis on End-to-End LDAs due to its advantages of easy implementation, high compatibility and configurability. This paper proposes a new LDA named UBLDA(Utilization Based Loss Differentiation Algorithm), which has the ability of estimating state(congestion or not) of network by calculating utility parameter based on the interval of packet arrival and sending rate. UBLDA can choose appropriate differentiation scheme based on state estimation, and integrates with TCP friendly transmission control protocol, making it a new congestion control mechanism suitable for wired-wireless heterogeneous networks.Finally, simulation experiments in NS2(Network Simulator-2) are carried out. The results show that the proposed algorithm has a promotion in the aspect of differentiation precision and resource utilization under variety of traffic/topology circumstances, which means that the algorithm could, to some extent, mitigate the defects of high misclass