【作者】 黄超；

【导师】 石为人；

【作者基本信息】 重庆大学 ， 控制理论与控制工程， 2008， 博士

【摘要】 普适计算是一种让人们随时随地都能获得信息服务的一种计算模式。它强调以人为本,关注的是人们的注意力以及人们对计算的满意程度。作为一个新兴的研究领域,普适计算受到越来越广泛的关注,它将对计算机、信息学科的发展产生广泛而深远的影响。无线自组织网络作为实现普适计算的一种新型技术,是由一组带有无线通信收发装置的移动终端节点组成的一个多跳、临时、无中心的移动通信网络,不需要基础网络设施的支持,可以在任何时候、任何地点快速构建。无线自组织网络在许多特殊情况下有着不可替代的作用,可广泛应用于国防战备、灾难援助等无法得到有线网络支持或某些临时需要通信但建立有线通信网络代价太大的环境中。尤其是在未来战场上,无线自组织网络对于高技术武器装备、集中指挥、协同作战和提高作战机动性等具有很好的应用前景。快速可靠的路由是无线自组织网络具有高可靠性、高抗毁性和高移动性的基础,是无线自组织网络研究的关键技术之一。无线自组织网络使用宽带较窄的无线信道,且由于节点的移动造成拓扑变化比较频繁,如果直接将传统路由协议应用于无线自组织网络中,周期性的控制信息将会占用大量的无线信道资源,降低系统效率。因此,构建有效的适合自身特点的路由成为了无线自组织网络研究的极为重要的课题。同时,由于无线自组织网络节点一般使用电池供电,且受技术的限制,电池的容量在短期内很难得到大规模的提高,而对于无线自组织网络这种有特殊用途的网络来说,延长网络工作时间又显得尤其重要。因此,无线自组织网络的节能研究同样具有重要的意义。本文对无线自组织网络的研究主要包括两大方面:路由算法和低功耗节点技术。主要贡献是:普适计算环境下,多个嵌入式设备之间的协作成为了嵌入式技术重要的研究内容,基于此,提出了多嵌入式系统新概念;无线自组织网络是普适计算实现的支撑技术之一,针对无线自组织网络的可扩展性和能量问题,在对现有分布式路由算法进行综合分析的基础上,设计了一种基于连通度和能量感知的按需自维护分簇路由协议,同时随着实时多媒体等业务在无线自组织网络中的出现,提出了一种基于带宽约束和能量感知的分布式QoS路由协议;最后针对无线传感器网络的能耗问题,在波束供电技术的基础上,提出了一种低功耗射频唤醒无线传感器网络节点的设计方法。作为一项具有创新性意义的工作,论文在研究方法与思路上力求有所突破,其主要研究成果包括如下几个方面:①对普适计算的发展历史、现状、技术难点和研究热点进行了综述,分析和讨论了普适计算的概念和特性,重点探讨了多嵌入式系统新概念以及多嵌入式系统的结构框架,并对目前一些具有代表性的普适计算研究项目进行了简述。②对无线自组织网络进行了较为全面的分析和总结,重点讨论了无线自组织网络的分布式路由算法,结合平面路由机制和分簇算法,提出了一种基于连通度和能量感知的按需自维护分簇路由协议。该路由协议采用了一种以分簇路由为主,平面按需路由为辅的工作机制。通过仿真表明按需自维护分簇路由协议在保持了平面按需路由优点的基础上,有着更好的可扩展性,提高了网络性能。③系统地讨论了无线自组织网络的QoS保证体系,重点分析了无线自组织网络的QoS路由。针对现有QoS路由算法大多没有特别考虑节点的能量约束,而带宽保证又是实时应用最关键的需求之一,提出了一种基于TDMA机制的带宽约束和能量感知的分布式QoS路由协议,将路由发现、时隙预留以及维护结合起来,满足无线自组织网络对QoS路由的需求。④从通信的角度讲,无线传感器网络可以看成是一种特殊的无线自组织网络。论文对无线传感器网络进行了概述,指出低功耗和实时性正是无线传感器网络应用中需要解决的重要问题,并针对无线传感器网络通常采用的周期性睡眠/唤醒机制在能耗和实时性方面的不足,提出了一种无线传感器网络节点的低功耗射频唤醒机制,分析了基于这种低功耗射频唤醒机制的无线传感器网络节点的硬件总体结构和节点设计。通过性能对比分析,表明了这种低功耗射频唤醒机制在无线传感器网络中的有效性。更多还原

【Abstract】 Pervasive computing is a computing mode which enables people to attain information services anywhere and anytime. It humanitarianly emphasizes people’s attention and their satisfaction with information service. As a booming research field, pervasive computing gets more and more attention from people, which will greatly influence the development of computers as well as information disciplines. The Ad Hoc network, one non-centre transient network comprised by a group of wireless and mobile terminal nodes, is one important new technology to realize pervasive computing, which can be swiftly set up without any information-based supporting facility at any place and any time. Thence, the Ad Hoc network is irreplaceably used in the situation like civil defense equipment, emergency rescue, where it’s too costly to set up wire network. And in the future battlefield, the Ad Hoc network will be more and more used in hi-tech weapons, military centralization, military joint operation and military operation maneuverability, etc.Speedy and stable routes are the basis of hi-stability, hi-destroy-proof, and hi-mobility Ad Hoc network, one of the key technologies for the research of the Ad Hoc network. The Ad Hoc network is typically characterized by bandwidth-constrained wireless links and dynamic topology, leading to frequent and unpredictable connectivity changes. So if the traditional route is applied in Ad Hoc networks, the periodic controlled information will take up too many wireless resources. Accordingly, how to create the efficient route adapting to the characteristics itself becomes one of the primary research projects of Ad Hoc networks. Besides, the Ad Hoc network usually takes batteries as its power resources, whose volume can’t be much improved in a short time for the poor technology. Hence, the prolonging of the working time of batteries becomes especially essential for the Ad Hoc network. The research on the energy saving of Ad Hoc networks becomes very important.This paper researches in two parts of the Ad Hoc network, including routing arithmetic and low energy consumption. The main sacrifices of the paper are as follows. Firstly, collaborations among many embedded devices become the important research areas under pervasive computing. So the new concept of multi-embedded system is put forward. Secondly, the Ad Hoc network is one of the supporting technologies of achieving pervasive computing, and an on-demand self-maintenance clustering routing protocol based on connectivity and energy awareness is addressed for the extension and energy issue of the Ad Hoc network. Thirdly, a distributed QoS routing protocol based on bandwidth constraint and energy awareness is designed for the real time multimedia services and so on. Finally, a design method of the wireless sensor network(WSN) node with the characteristics of low energy consumption and radiation frequency arousing is put forward. The important research results are as follows:①The development history, situation and research highlights of pervasive computing are presented, the concept and characteristics are analyzed. Especially, the new concept of multi-embedded system and its framework are discussed. And also the representative projects of pervasive computing research are introduced.②The Ad Hoc network is analyzed comprehensively, especially the distributed routing arithmetic. Combined with flat-based routing mechanism and clustering arithmetic, an on-demand self-maintenance clustering routing protocol based on connectivity and energy awareness is put forward which cited a mechanism with clustering routing key point and with flat-based on-demand routing supplementary point. The simulation results show its validity. This protocol keeps the advantages of flat-based on-demand routing, improves the scalability, and enhances the network performance.③The QoS routing of Ad Hoc networks is discussed. Most present QoS routing arithmetic is sophisticated and don’t take energy constraint into consideration, while bandwidth guarantee is one of the key requirements for the real time application. So the paper addresses a distributed QoS routing protocol based on bandwidth constraint and energy awareness to hang the routing discovery and slot reservation as well as maintance together for the QoS routing demanding.④From the point of communication view, WSN could be treated as a special Ad Hoc network. This paper summarizes WSN, pointing out energy consumption and real time performance is the most important problem of WSN. According to the demerit of periodical sleeping and waking mechanism in WSN, the paper brings forward a new mechanism with the characteristics of low energy consumption and radiation frequency arousing, and also analyzes the hardware structure and designation of WSN node. Performance comparison demonstrates the effect of the mechanism in WSN.更多还原