Effective Content Distribution Technique for Wireless Internet

在无线因特网中，移动的用户将利用无线介质的灵活可访问性来接收各种内容。本研究研究了以下几种适用于无线互联网的有效且强大的内容分发技术。1.无线多播通信中的拥塞控制技术无线多播通信的典型方式会导致整个系统性能的下降。这是因为无线信道质量的频繁变化带来了代表节点的频繁变化。提出了一种新的拥塞控制方法，利用网络支持技术解决了这种典型的波动问题.无线传输协议的发展我们指出，在不同的协议层的重传控制的不匹配和大的带宽变化在不同的无线网络切换是无线TCP的重大技术问题。针对前一个问题提出了跨层方法，针对后一个问题提出了ACK划分技术.应用层组播覆盖网络的鲁棒控制我们提出了一种新的覆盖网络构造方法，它考虑了鲁棒性。在我们所提出的方案中，移动的主机被尝试位于覆盖组播树的较低层，这导致了一个健壮的网络结构，即使有移动的用户.无线ad-hoc网络的内容分发技术我们开发了一个实验系统与笔记本电脑的这是由该基金准备。利用该实验系统，研究了ad-hoc网络中的内容传输，并对组播拥塞控制协议进行了评估。

In wireless Internet, mobile users will receive various contents with making use of flexible accessibility of wireless medium. In this research, several effective and robust content distribution techniques shown below which are suitable for wireless Internet have been studied.1. Congestion control technique for wireless multicast communicationsRepresentative approach of wireless multicast communications will cause performance degradation of total system. This is because frequent change of wireless channel quality brings frequent change of the representative node. We propose a new congestion control method which resolves this representative fluctuation problem by making use of network support technology.2. Development of wireless transport protocolWe show that mismatch of retransmission controls in different protocol layers and large bandwidth change in different wireless network handover are significant technical problem for wireless TCP. We propose cross layer approach for the former problem and ACK dividing technique for the latter problem.3. Robust overlay network control for application level multicastWe propose a new overlay network construction method which takes into account robustness. In our proposed scheme, mobile hosts are tried to be located in the lower layer of overlay multicast tree, which leads to a robust network structure even with mobile users.4. Content distribution technique for wireless ad-hoc networksWe develop an experimental system with note PC's which were prepared by this grant. With this experimental system, content delivery in ad-hoc network is investigated and multicast congestion control protocol is evaluated.