【作者】 沈琳；

【导师】 是湘全；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2011， 博士

【摘要】 无线传感器网络(Wireless Sensor Networks, WSN)具有开放的环境、动态变化的拓扑结构和资源受限的节点,这些独特的网络特征使其数据传输、安全技术等问题成为这一领域的研究热点和难点。本文研究的网络结构与数据传输技术就是其中关键性和富于挑战性的问题。具体工作主要包括以下几个方面：本文的第一部分工作致力于设计一个简单、高效的无线传感器网络分簇算法。良好的网络拓扑结构是可靠数据传输的基础。我们首先分析了现有的ad hoc网络中的分簇算法和WSN中的分簇算法。这些协议或者没考虑各个网络节点传输数据的相关性,或者认为数据融合是理想情况下的,即数据完全相关,以至于同一簇内几个数据包可压缩为一个数据包。然而,在实际的无线传感器网络中,数据融合的程度和数据相关性是有紧密联系的。因而,很有必要研究部分数据相关的分簇特性。通过分析数据融合对分簇网络能量的影响,提出了一种基于节点位置的WSN分簇算法。实验结果显示该算法效率较高,在已知位置信息的情况下,调节数据传输速率可以使无线传感器网络的寿命延长两倍,并且算法易于实现。本文的第二部分工作是在第一部分分簇算法的基础上,提出了一个动态密钥安全数据传输方案。安全问题是可靠数据传输的关键。该方案假设无线传感器网络系统已经配备了有效的安全检测机制,来检测传感器节点是否被俘虏或已经耗尽能量。WSN有一些特殊的性质,如计算能力有限性、节点的移动性、大规模的部署性、无人操作性、有限的通信带宽和存储资源等。在WSN中这些性质加上高风险的物理攻击对于无人操作的节点在安全方面具有一定的挑战性。我们研究发现网络安全与簇头的更新有关。低功耗、计算工作量的减少和安全性的增强是区别其他方案的关键。因此在方案中采用了对称密钥系统,子协议的组成定义了在传感器网络过程中密钥如何被分配、补充、撤销和更新。本文的第三部分工作是研究WSN的可靠性中的重要的组成部分——拥塞控制。当前许多工作都对拥塞检测度量进行了研究,希望能够找到精确和低开销的拥塞检测方法。当判断拥塞即将或己经发生时,应该立即采取措施有效缓解拥塞,当前的缓解策略也很多,大都是通过将拥塞消息回传到数据源节点要求降低数据发送率。本文提出了一种能量有效的拥塞控制算法(Energy Efficient Congestion Control, EECC),该算法能够依据缓冲队列使用情况进行拥塞检测,通过建立新的传输路径和调节节点数据发送速率以实现拥塞缓解。本文的第四部分工作研究了一种GPRS和ZigBee相结合的传感器网络异构互联的实施。异构网络之间的数据传输增强了WSN应用的可操作性。利用GPRS和ZigBee技术,设计并实现一个移动无线传感器节点,取名为SenCar。该节点的主要功能是用于移动无线传感器网络中对区域内相关位置的信息感知,并通过GPRS网络将数据发给后台控制基站。在整个无线传感器网络中,ZigBee网络把采集到的数据通过GPRS网络经Internet上传到监控中心。ZigBee网络面向短距离通信,而GPRS网络面向远距离的通信,两者能够优势互补,通过网关将两种网络联系到一起,实现了数据的远距离传输。最后对本文工作进行了总结,并探讨了无线传感器网络结构与数据传输技术研究的进一步工作。更多还原

【Abstract】 Wireless sensor networks (WSN) have exoteric environment, dynamic topology structure and limited resource node, which enables its security issue to be the research hotspot and difficulty point of this field. This thesis is focus on structure and reliable data transmit of WSN, and the framework is as following:To begin with, this thesis commits to designing a simple and efficient cluster-based algorithm of WSN. We firstly analyze the present cluster-based algorithms in ad hoc network and WSN, of which the most do not consider the pertinence of transmit data in each network node or reasonable data integration, i.e., data packet in same cluster can be compassed to be entirely one. However, the extent of data integration and data pertinence are closely connected to each other in a practical WSN. As a result, it is necessary to observe the partial characteristics of a cluster-system in effect to cluster-system network energy. After that,we propose a WSN cluster-system algorithm based on node station. It can be concluded that this method is highly effective and accomplishable to double the transmission speed.In the second part, we put forward a flexible cipher code project based on the cluster algorithm. This project supposes that WSN has already been equipped with effective security detection mechanism to inspect whether transducer node is captured or already consumed. WSN has the following special features, such as limited calculating ability, removeable node, large-scale disposal, self-serviced manipulation, narrow bandwidth and storied resources. All of these features plus high risk of physical attack. All of these bring great challenge on security toward unmanned operation node, thus security issues of WSN are significant. We’ve found that network security is related to renovation of cluster-system; low consumption, reduced calculation workload and increased security are the key to distinguish with other projects. Therefore, symmetry cipher code system is adopted in this project, which defines distribution, supply, cancellation and renovation in network.Moreover, in the third part, we study the important constituent part of reliability of WSN--- Congestion Control. A great deal of literature has been devoted to the check measurement of congestion control, in order to find precise and cheap ways for congestion inspection. When congestion will or has appeared, we should take effective measures to relieve congestion. There are many congestion strategies at the present, most of which are made by passing back information to data source node to decrease transmit data. Different control algorithm requests different mechanism to effectively release congestion. A new method of Energy Efficient Congestion Control are proposed to inspect congestion in accordance with service condition of cushion queue, and the congestion release is completed by means of establishing new transmit canals and modifying node data to higher speed rate.Finally, the last part of this thesis research heterogeneous system on internetworking of WSN between GPRS and ZigBee. We design and accomplish a mobile wireless sensor node integrated GPRS and ZigBee technology. The main function of the node is to transport information perception of relevant location in WSN, and send data to BaseStation through GPRS. Among the entire WSN, ZigBee network uploads collected data to control center in Internet by GPRS. ZigBee is designed to short distance communication while GPRS to long distance. The advantages of the two networks are trade-offed to each other; If putting both networks together, we are able to construct a complete long-distance transmission network.In a word, this thesis explores the structure problems in WSN and conducts reliable data transmission issues.更多还原