Power-Efficient Ad Hoc Mobile Networking

考虑一下在遭受自然灾害的地区建立临时网络的问题。例如，这样的网络将允许现场的医务人员从医院数据库中检索病人的历史，允许保险公司从现场提出索赔，等等。理想情况下，建立这样一个网络只需要给医护人员配备具有无线电功能的pda（个人数字助理），并提供一个或多个“网关”，将这个自组织网络与外部世界连接起来。建立这样一个网络的一个基本问题是在自组织网络的节点之间路由数据包。为什么这是一个难题？主要原因是随着节点的移动，网络拓扑结构会发生变化，因此需要不断更新路由。此外，自然障碍可能会在短时间内对网络产生分割作用。因此，去往不再位于分区中的目的地的数据包可能会被丢弃（即使分区是短暂的）。最后，任何解决方案的一个过度限制是每个手机的电池寿命都非常有限。因此，虽然特定的协议可以最优地路由数据包，但它可能会导致过度的电量消耗，从而导致移动设备很快耗尽电量。在这项研究中，我们将开发节能的路由协议（即，最大限度地延长移动设备的电池寿命），同时仍然提供接近最佳的路由功能。此外，这些协议将通过执行基于需求的路由发现来支持服务质量（QoS）保证。对QoS的其他协议支持，如动态适应带宽变化的损失配置文件，也将被纳入其中。最后，路由协议将实现缓存转发数据包路由，以处理短暂的网络分区。与本研究项目相关的论文和其他文件可在http://www.cs.sc.edu/~singh/adhoc.html上找到。

Consider the problem of establishing a temporary network in a region hit by some natural disaster. Such a network would, for example, allow medics in the field to retrieve patient history from hospital databases, allow insurance companies to file claims from the field, etc. Ideally, setting up such a network should involve no more than equipping medics with PDAs (Personal Digital Assistants) that have radio capability and providing one or more ``gateways'' that connect this ad hoc network with the outside world. A fundamental problem in setting up such a network is routing packets between nodes in the ad hoc network. Why is this a difficult problem? The primary reason is that as nodes move about the network topology changes and thus routes need to be constantly updated. Furthermore, natural obstacles may have the effect of partitioning the network for brief periods of time. Thus, packets enroute to a destination that no longer lies in a partition may be dropped (even though the partition is short-lived). Finally, an overreaching constraint on any solution is the problem of very limited battery life at each mobile. Thus, while a specific protocol may route packets optimally, it may cause an inordinate amount of power drain causing mobiles to run out of power quickly. In this research, we will develop routing protocols that are power-efficient (i.e., the battery life of mobiles is maximized) while still providing near-optimal routing functionality. In addition, these protocols will support Quality of Service (QoS) guarantees by performing demand-based route discovery. Other protocol support for QoS, such as loss profiles for dynamic adaptation to bandwidth changes, will also be incorporated. Finally, the routing protocols will implement cache-and-forward packet routing to deal with short-lived network partitions. Papers and other documents related to this research project may be found at http://www.cs.sc.edu/~singh/adhoc.html.