无线传感器网络分布式时间同步算法研究

发布时间：2018-01-13 00:36

本文关键词：无线传感器网络分布式时间同步算法研究　出处：《西安电子科技大学》2014年博士论文　论文类型：学位论文

【摘要】：随着物联网在社会需求方面的迅速增长,作为物联网核心组成部分——无线传感器网络受到学术界和工业界越来越多的重视。时间同步是无线传感器网络的一个关键技术,它对于实现数据融合、协同传输、网络安全以及目标跟踪等具有重要意义。理论研究和工程实践表明:时间同步是将理论研究转化为实践的主要瓶颈问题。论文基于这些事实背景,对无线传感器网络的分布式时间同步算法做了较为详尽的探讨,主要工作和创新如下:1无线传感器网络缺乏基础设施、具有分布式、能量受限、存储及计算能力受限的特点,因此在设计无线传感器网络时间同步方案时,不能有太复杂的计算和路由选择。为了实现快速时间同步和降低网络能量消耗,论文研究了无线传感器网络时间同步广播同步算法。各个节点广播自己当前的时钟信息,对应的邻居节点接收到这些信息后,对接收到的信息做简单的算术平均,将平均值作为下一个时刻的时钟刻度再进行广播,此过程反复进行,最终会使网络所有节点的时钟达到一个相同的平均值,从而实现无线传感器网络的分布式同步,由于网络节点只接收来自邻居节点的广播信息,故该方案无复杂的路由选择,并且计算简单、收敛快速、能耗较低。2针对大规模无线传感器网络同步算法快速性的需求,提出一种基于多广播Gossip同步算法的大规模无线传感器网络时间同步方案。这种方案在同一时刻可以允许有多个节点同时广播时间信息,处于这些节点广播域中的节点分别接收并按照广播算法更新时钟信息。为了避免通信冲突和接收混乱,本方案依据图论要求广播节点之间的距离等于三。该算法可以提高无线传感器网络时间同步的收敛速度和同步精度,并且可以降低网络能耗。3针对传统无线传感器网络时间同步算法中存在的计算复杂度高和同步收敛速度慢等问题,提出单Gossip同步算法和多Gossip同步算法。单Gossip同步算法首先利用构造生成树算法得到一个生成树,然后依次对生成树每条边的两个节点的时钟信息进行Gossip运算,此过程反复进行,最终可使网络各个节点的时钟信息收敛于它们初始时钟信息的平均值。多Gossip同步算法对生成树进行边染色,相同染色的边可以同时进行Gossip运算。这两种同步算法减小了消息交换数,降低了计算复杂度,提高了同步收敛速度。4提出了一种增强型Gossip同步算法,该算法利用无线信道的广播特性来提高同步性能。在节点对的时钟信息交换过程中,一个节点向另一个节点发送时钟信息时,处于发送节点广播域中的其他节点也能收到此信息。这些节点将接收到的时钟信息和本地时钟信息的平均值作为自己的更新时钟。这样的过程在每个节点对之间反复进行,最终可使网络中所有节点的时间信息收敛到某一个固定值,从而实现网内时间同步。该算法也考虑了无线信道衰落和随机延迟对增强型Gossip同步算法的影响。5目前许多无线传感器网络的平均时间同步方案是按线性规则进行时钟更新的。然而在很多实际情况中,网络节点的算法可能需要非线性设计,所以论文也研究了无线传感器网络的非线性平均时间同步方案。网络中的相邻居节点时钟信息交换后按照一种非线性规则进行时钟信息更新。该规则必须符合一定的条件才能使网络所有节点同步于它们初始时钟的平均值。本文找到了使所有节点收敛到初始平均的充分条件。并用图论、李亚普诺夫理论和拉格朗日中值定理进行了证明。
[Abstract]:Along with the rapid growth in the social demand, as the core of the Internet of things -- part of the wireless sensor network by academia and industry more and more attention. Time synchronization is a key technology of wireless sensor network, to achieve data integration, cooperative transmission, network security has important significance and target tracking shows. Theoretical research and engineering practice: time synchronization is the theoretical research into practice. The main problem of these facts based on the background, the time of distributed wireless sensor network synchronization algorithm is discussed in detail, the main work and innovation are as follows: 1 Wireless Sensor Networks with distributed, lack of infrastructure, limited energy, characteristics the storage and computing ability is limited, so in the design of wireless sensor network time synchronization scheme, not too complex calculation and Routing. In order to achieve a rapid time synchronization and reduce network energy consumption, this paper studies the wireless sensor network time synchronization broadcast synchronization algorithm. Each node broadcasts its current clock information corresponding to the neighbor node receives the information, do the simple average of the received information, the average value as the clock ticks down a moment of broadcasting, this process is repeated, eventually all the network nodes clock reach the same average value, so as to realize the synchronization of distributed wireless sensor network, because network nodes only receive broadcast information from neighbor nodes, so the scheme without complicated routing, and simple calculation fast convergence, low energy consumption of.2 in large scale wireless sensor network synchronization algorithm of demand, proposed a large scale synchronization algorithm based on Gossip multicast Time synchronization scheme for wireless sensor networks. This scheme allows multiple nodes simultaneously broadcast time information at the same time, the node node in the broadcast domain respectively receive and broadcast algorithm according to update the clock information. In order to avoid communication conflicts and receive chaos, the scheme based on graph for broadcast distance between nodes is equal to three. This algorithm can improve the convergence speed of time synchronization of wireless sensor networks and synchronization accuracy, and can reduce the energy consumption of the network for the calculation of.3 time synchronization algorithm for wireless sensor networks in the traditional synchronous high complexity and slow convergence speed problem, proposed Gossip synchronization algorithm and multi Gossip synchronization algorithm. Single Gossip synchronization algorithm is constructed using the first generation get a spanning tree algorithm, and then followed by Gos clock information of the two node of each edge of the spanning tree The SIP operation, this process is repeated, the average convergence clock information of every node in the network to their initial clock information value. Multi Gossip synchronization algorithm for edge coloring of edges of the spanning tree, the same staining can be done at the same time Gossip operation. The two synchronization algorithm reduces the number of message exchange, reduces the computational complexity to improve the convergence speed of.4 synchronization, we proposed an enhanced Gossip synchronization algorithm, the algorithm makes use of the broadcast nature of wireless channel to improve the performance of synchronization. The node clock information of the exchange process, a node to another node sends clock information, at other nodes sending nodes in a broadcast domain can these nodes will receive this information. The average value of the received clock information and local clock information as their update clock. This process is repeated in each node to the end. The time information of all nodes in the network converge to a fixed value, so as to realize the network time synchronization. The algorithm also considers the wireless channel fading and random delay is in the linear rule clock update on the effects of enhanced Gossip synchronization algorithm.5 the average time of many wireless sensor network synchronization scheme. However, in many practical cases, the network node algorithm may require nonlinear design, so this paper also studies the nonlinear average time synchronization scheme in wireless sensor networks. The phase information of neighbor nodes in the network according to the clock after the exchange of a kind of nonlinear rules of the clock information update. The rule must meet certain conditions in order to make all the network nodes on average they are synchronized to the initial clock value. This paper has found that all nodes converge to the average of the initial sufficient conditions. And by using graph theory, Li Ya Lyapunov theory and the Lagrange theorem are proved.

【学位授予单位】：西安电子科技大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TN929.5;TP212.9

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