Research on Wireless Internetworking and Application Support

我们工作的目标是建立一个网络平台，在这个平台中，移动的应用可以透明地支持各种无线接入技术。(1)无线互联技术的发展与实现在无线互联技术中，提出了公平调度算法。详细设计并实现了无线局域网的信道分配算法和最小带宽保证调度器。采用Linux操作系统实现了实验床，并对高密度网络体系结构进行了研究。在高密度网络中，我们假设有大量的联网设备。为了实现这种网络结构，必须处理节点的异构性。为此，我们提出了稳定性自适应路由和多对一通信协议。这些协议都是通过ns-2（网络模拟器2）模拟。(2)应用支持服务的开发和试验床网络的制作开发了高速无线网络中的按需数据预取系统。在这样的高速网络中，由于不连续的小小区，移动台只能停留很短的时间。我们的方法利用另一个接入网络进行数据请求，并利用高速网络进行数据下载。我们制作了测试床网络，其中移动的主机有两个网络接口PHS和WaveLAN。实验结果表明，即使骨干网络发生拥塞，我们的预取方法也可以保持高吞吐量。

The goal of our work is to establish a networking platform in which mobile applications can be supported transparently with various wireless access technologies.(1) Development and Implementation of Wireless Internetworking TechnologyAs for wireless internetworking technology, fair scheduling algorithms were developed. In detail, Channel assignment algorithms for wireless LAN, and minimum bandwidth guaranteed scheduler were designed and implemented. We made testbed implementation by using Linux operating system.High density network architecture was also studied. In high density network, we assume tremendous number of networked devices. The nodes heterogeneity must be handled for achieving this network architecture. Toward this, we proposed stability adaptive routing and many-to-one communication protocol. These protocols were simulated by ns-2 (network simulator 2).(2) Development of Application Support Service and Making of Testbed NetworksOn-demand data prefetching system in high-speed wireless networks was developed. In such high speed networks, mobiles can stay for only short time due to the discontinuous small cells. Our method utilizes another access network for data request and high-speed network for data downloading.We made tastbed networks in which mobile hosts have two network interfaces, PHS and WaveLAN.Experimental results show our prefetching method can keep high throughput even when congestion occurs in backbone networks.