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建具有不同传输速率、覆盖范围、功率水平、移动性水平、服务和价格水平的许多不同类型的无线电接入网络（诸如WWAN、WLAN和WPAN）的部署。在这种异构架构中，配备有多网络接口的设备（即，多模式终端）应当能够执行网络选择、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种集成的异构无线网络，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QoS要求。该提议引入了新的水平和垂直跨层特征，其允许多模终端机会性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估计，并使用来自多个接口的不同层的信息，以确定哪种连接性替代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，所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整体系统性能。这种用于连接和切换管理的有效解决方案可以导致显著的性能增强。

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.