【作者】 Sadia Aziz；

【导师】 Li Layuan；

【作者基本信息】 武汉理工大学 ， Computer Applied Technology， 2007， 博士

【摘要】 移动AdHoc网络是当前研究中最热门的领域之一。究其原因就几个：第一个是使用这种网络的成本比较低廉，第二个是这种网络位置的不确定性，第三个是最重要的原因就是任何非专业人士都可以安装这种网络。这种信赖程度导致各种移动设备发展很快和变得流行。同时不同的无线网络技术的引入，使得移动设备相互传送报文成为可能。因此，当我们谈论AdHoc网络时，就要提起广播。由于移动设备进行通信都依赖于广播，从而广播是Ad Hoc网络的基本特性。在论文中，我的工作主要集中在对目前存在的算法进行改进。出于这个目的，我们使用了跨层设计。因此我们主要的焦点是来使用这个设计来提高广播算法技术。由于这种模块化的网络层次对于标准化和实现提供了方便，每一个被独立设计的层和相邻的层进行通信，基于这个思想，考虑用跨层设计来合并这些不同的层。跨层暗含着同时考虑所有网络层次的整体设计。作为选择，在已经存在的整体设计方式中在不同的层中选择不同的参数，这就是我们设计所解决的问题。在我们的设计方案中，我们已经使用了不同层的参数来消除一些控制报文的负载，从而为提高广播效率来收集更准确的网络信息。因而，在这项工作中，我们研究了在部分网络层次上：MAC层，网络层和物理层一种非最优的跨层迭代方法。特别的，为了合并设计MAC协议，链路设计和选择最佳样本周期，我们首先得到网络层和物理层的信息和对适应性和最佳支持时钟的MAC层信息。通过实验结果，我们已经证明了跨层设计能够降低广播的冗余，以此来避免移动Adhoc网络的广播风暴。这些算法的目的是通过使用满足自适应行为的跨层参数来减少重传数据包的个数。更多还原

【Abstract】 Mobile Ad Hoc Network is one of the hottest research areas now a day. There are several reasons for this. One of them is its low cost to employ the network. Second is its freedom of location, and third and most important is, it can be installed by any layman. So ad hoc networks have become a promising research field in recent years. This credit also goes to the rapid development and popularity of various mobile devices. Different wireless technologies have been introduced to enable message communications between mobile devices. So when we talk about Mobile Ad Hoc Networks, it is must to talk about the broadcasting. Broadcasting is the basic feature of Mobile Ad Hoc Networks because all the communication among the mobile devices depends on the broadcasting.In this dissertation, my work has focused on improving the efficiency of already presented algorithms. For this purpose we have used the Cross Layer Design. So our main focus is to use Cross Layer Design for improving broadcasting techniques. As layering provides the network design with modularity that facilitates standardization and implementation, and each layer is designed separately with control messages passing between adjacent layers so the idea of cross-layer design is to jointly design these different layers. Cross-layer design can imply a joint design across all network layers simultaneously, which is highly complex. Alternatively, it can entail choosing parameters at different network layers from existing designs in a joint fashion, which is our design approach. In our design approach we have used the parameters of different layers for removing some control message overhead, for collecting the network information more precisely for improving the broadcast efficiency.Thus, in this work, we study a suboptimal iterative method of cross-layer optimization over a subset of the network layers: the MAC layer, Network Layer and the Physical Layer. In particular, to jointly design the MAC protocol, the link design and select the optimal sample period, we first get the information of network layer and physical layer and use these information at MAC layer for adaptation and for optimizing the back off timer.From the experiment results we have proved that Cross Layer Design helps in reducing the broadcast redundancy so as to avoid the broadcast storm problem in MANETs. The aim of algorithms is to reduce the number of retransmission by using Cross Layer metrics for adapting adaptive behavior.This dissertation is supported by National Natural Science Foundation of China (No. 60672137, 90304018), Specialized Research fund for Doctoral Program of higher Education of China (No. 20060497015), and Key Project of Wuhan, Hubei Province of China (No. 20041001001).更多还原