Scalable ad hoc and sensor networks

虽然技术无法预防地震或海啸等灾害，但移动的自组织网络（MANET）在预测这些灾害和灾后救援方面具有重要意义。 MANET是一种不依赖于现有基础设施并支持移动的用户的无线通信网络。 由于这种网络中的节点不需要能够彼此直接通信，因此MANET通常是多跳的，并且经常需要中间节点来中继网络中相距较远的节点之间的消息。 除了救灾和救援任务等应用外，无线传感器网络（WSNs）是移动的ad hoc网络技术的最主要实现方式之一。 尽管在这一领域的许多研究活动，最重要的因素阻碍了更广泛的部署大型移动自组网的可扩展性问题。 也就是说，随着网络中节点数量、节点密度和节点移动的增加，用户数据消耗的网络带宽和设备能量的百分比以及每个节点的吞吐量急剧下降并接近于零。 为了解决可扩展性问题，该项目中采用的方法是在网络节点之间引入层次结构，以帮助克服这些问题，无论是使用设备异构性还是叠加逻辑结构。 这涉及到以本地化的分布式方式构建具有所需属性的层次结构，并在网络条件发生变化时对其进行维护。 我们的目标是拥有一个易于维护的分层结构，并允许网络协议在不消耗太多有限网络资源的情况下进行良好的扩展。 为了解决这些问题，本项目将采取分析和实验两种方法。 特别是，数学优化和近似将用于制定和解决这些性能优化问题。 另一方面，为了克服分析模型可能的不准确性，将使用计算机模拟来验证协议的性能。 更现实和忠实的性能评估将通过使用执行各种协议的测试网络进行研究。

While technology cannot prevent disasters such as earthquake or tsunami, mobile ad hoc networks (MANETs) promise significant benefit to forecasting these and to the disaster relief afterwards.  A MANET is a wireless communication network that does not rely on existing infrastucture and supports mobile users.  Since nodes in such a network are not required to be able to communicate with each other directly, a MANET is usually multi-hop and intermediate nodes are often needed to relay messages between nodes in the network that are far apart.  In addition to applications such as disaster relief and rescue tasks, wireless sensor networks (WSNs) is one of the most implementations of the mobile ad hoc networking technology.  Despite many research activities in this area, the most significant factor hindering wider deployment of large MANETs is the scalability issue.  That is, the percentage of network bandwidth and device energy consumed by user data, and the per-node throughput decrease dramatically and approach zero as the number of nodes in the network, the node density, and movements of node increase.  To address the scalability issue, the approach employed in this project is to introduce a hierarchy among the network nodes to help overcome these problems, whether using device heterogeneity or superimposing logical structures.  This involves constructing a hierarchy with desired properties in a localized distributed fashion and maintaining it when the network conditions change.  The goal is to have a hierarchical structure that is easily maintained and will allow network protocols to scale well without consuming too much of the limited network resources.       To solve these problems, this project will resort to both analytical and experimental methods.  In particular, mathematical optimization and approximation will be used to formulate and solve these performance optimization problems.  On the other hand, to overcome the possible inaccuracy of analytical models, computer simulations will be used to verify the protocol performance.  More realistic and faithful performance evaluations will be carried out by the use of testbed networks that execute various protocols under study.