NeTS-WN: Collaborative Research: Supporting Multi-mode Terminals in Integrated Heterogeneous Wireless Netowrks

便携式计算和无线技术的快速发展正在创造许多不同类型的无线电接入网络的部署，例如具有不同传输速率、覆盖范围、功率水平、移动性水平、服务和价格水平的WWAN、WLAN和WPAN。在这种异质架构中，配备多网络接口的设备(即多模终端)应该能够执行网络选择、位置更新、寻呼以及水平和垂直切换。该方案的目标是提供一个集成的异质无线网络，以支持多网络环境中的多模终端，其中终端利用多个接口来满足服务质量要求。该方案引入了新的水平和垂直跨层功能，允许多模终端机会主义地利用可用的多网络。这些新功能包括网络可用性检测和链路质量评估，并跨多个接口使用来自不同层的信息，以确定哪个连接备选方案最符合应用程序的要求。多模式协议栈将被定义为使得它不需要对现有协议进行任何修改，从而不同的无线技术也可以支持多连接切换和多网络接口。从系统的角度来看，提出的解决方案可以通过将流量重定向到适当的网络来帮助提高系统的整体性能。这样一种有效的连接和切换管理解决方案可以显著提高性能。

Rapid advances in portable computing and wireless technologies are creating deployments of many different types of radio access networks such as WWANs, WLANs, and WPANs with different transmission rates, coverage ranges, power-levels, mobility-levels, services and price-levels. In such a heterogeneous architecture, devices equipped with multi-network interfaces (i.e., multi-mode terminals) should be capable of performing network selection, location update, paging, and horizontal and vertical handoff. The objective of this proposal is to provide an integrated heterogeneous wireless network to support multi-mode terminals in the multi-network environment, where the terminals take advantage of multiple interfaces to satisfy the QoS requirements. This proposal introduces new horizontal and vertical cross-layer features that allow multi-mode terminals to opportunistically exploit the available multi-networks. These new features include network availability detection and link quality estimation, and use information from different layers across multiple interfaces, in order to decide which connectivity-alternative best matches the requirements of an application. The multi-mode protocol stack will be defined such that it does not require any modifications to existing protocols so that different wireless technologies can also support multi-connection handoff and multi-network interfaces. From the system's perspective, proposed solution can help improve the overall system performance by redirecting the traffic to appropriate networks. Such an effective solution for connection and handoff management can lead to drastic performance enhancements.