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On location support and one-hop data collection in wireless sensor networks.

机译：无线传感器网络中的位置支持和一跳数据收集。

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摘要

We consider two fundamental building blocks for many applications in wireless sensor networks---location support and efficient medium access for one-hop data collection.; In the first part of the thesis we identify two important problems of location support---accurate localization and fast & fair localization---and propose novel solutions. We address the problem of accurate localization by proposing two novel, light-weight RF localization techniques called Ecolocation and Sequence-Based Localization. We define constructs called location constraints and location sequences based on distance ranks of reference nodes from the location of the unknown node and use them for localization. We compare and contrast the two localization techniques and show their robustness to RF channel non-idealities through examples. Through extensive systematic simulations and a representative set of real mote experiments, we show that our light-weight RF localization techniques provide comparable or better accuracy than other state-of-the-art radio signal strength-based localization techniques over a range of wireless channel and node deployment conditions.; In addition to being accurate, the location support service should also be fast and fair. The response times of the reference nodes to localization requests from the unknown node should be minimized and multiple unknown nodes, at different locations, should not have widely varying response times. We identify this as a fast/fair localization problem and formulate it as a min-max optimization problem, show that it is related to the well-known, NP-hard, maximum broadcast frame length problem, and investigate a heuristic scheduling based solution. We study the attributes that determine the response times of the reference nodes, called the localization delay, and derive closed-form expressions for it. We then investigate the heuristic solution's performance in terms of localization delay, fairness and average and minimum localizable speeds.; In the second part of the thesis, we address the problem of medium access for one-hop data collection, which occurs frequently in many wireless sensor network applications. We consider a wide spectrum of one-hop data collection applications with continuous data collection at one end and one-shot data collection at the other. While in the continuous data collection problem the contending wireless nodes always have a packet to transmit, in the one-shot data collection problem each contending node has a single packet to transmit. Medium access mechanisms for continuous data collection have been studied extensively in the past by numerous researchers, but such mechanisms for one-shot data collection have received much less attention. In this thesis we address the medium access problem for this spectrum of application scenarios through three different pieces of work.; We model and analyze the performance of slotted Aloha medium access techniques for the one-shot data collection problem. Owing to the transient nature of the network in this problem we use non-ergodic Markov chain analysis and derive flow equations that accurately capture the temporal dynamics of the network. Using these equations we evaluate the medium access techniques' performance in terms of delay and energy consumption.; We then present a novel location-aware medium access protocol for the one-shot data collection problem that uses the location information of contending nodes to reduce collisions and improve the overall performance. We evaluate the protocol in terms of delay and energy consumption and compare it with location-unaware medium access protocols using simulations. Results show that our protocol can take advantage of the location distribution of nodes to provide significantly lower delay and energy consumption compared to location-unaware protocols.; Finally, we model, analyze, and evaluate the performance of the IEEE 802.15.4 MAC protocol for both ends of the one-hop data collection app
机译：对于无线传感器网络中的许多应用，我们考虑了两个基本的构建基块-位置支持和用于单跳数据收集的有效介质访问。在论文的第一部分中，我们确定了位置支持的两个重要问题-精确定位和快速公平的定位-并提出了新颖的解决方案。我们通过提出两种新颖的轻量级RF定位技术（称为“生态定位”和“基于序列的定位”）来解决精确定位的问题。我们基于参考节点到未知节点位置的距离等级，定义了称为位置约束和位置序列的构造，并将其用于定位。我们比较和对比了两种定位技术，并通过示例展示了它们对射频信道非理想性的鲁棒性。通过广泛的系统仿真和一组代表性的真实微粒实验，我们表明，在一系列无线信道上，我们的轻型RF定位技术与其他基于无线电信号强度的最新定位技术相比，具有可比或更高的精度以及节点部署条件。除了准确之外，位置支持服务还应该快速，公平。参考节点对来自未知节点的本地化请求的响应时间应最小化，并且在不同位置的多个未知节点的响应时间不应相差很大。我们将其识别为快速/公平的本地化问题，并将其公式化为最小-最大优化问题，表明它与众所周知的NP-hard最大广播帧长度问题有关，并研究基于启发式调度的解决方案。我们研究确定参考节点响应时间的属性（称为定位延迟），并为其导出闭合形式的表达式。然后，我们从本地化延迟，公平性以及平均和最小本地化速度方面研究启发式解决方案的性能。在论文的第二部分中，我们解决了单跳数据收集的媒体访问问题，这种访问在许多无线传感器网络应用中经常发生。我们考虑了广泛的单跳数据收集应用程序，其中一端是连续数据收集，另一端是一发式数据收集。虽然在连续数据收集问题中，竞争的无线节点始终有一个要发送的数据包，但是在单发数据收集问题中，每个竞争的节点都有一个要发送的数据包。过去，许多研究人员已经广泛研究了用于连续数据收集的媒体访问机制，但是这种用于单次数据收集的机制却很少受到关注。在本文中，我们通过三项不同的工作来解决这一应用场景范围的媒体访问问题。我们为一键式数据收集问题建模和分析了时隙Aloha介质访问技术的性能。由于此问题中网络的瞬态性质，我们使用非遍历马尔可夫链分析并得出可精确捕获网络时间动态的流量方程。使用这些方程式，我们根据延迟和能耗来评估媒体访问技术的性能。然后，我们针对单次数据收集问题提出了一种新颖的位置感知媒体访问协议，该协议使用竞争节点的位置信息来减少冲突并提高整体性能。我们根据延迟和能耗评估协议，并使用模拟将其与位置不知道的媒体访问协议进行比较。结果表明，与不知道位置的协议相比，我们的协议可以利用节点的位置分布来显着降低延迟和能耗。最后，我们为单跳数据收集应用程序的两端建模，分析和评估IEEE 802.15.4 MAC协议的性能

著录项

  • 作者

    Yedavalli, Kiran Kumar.;

  • 作者单位

    University of Southern California.$bElectrical Engineering.;

  • 授予单位 University of Southern California.$bElectrical Engineering.;
  • 学科 Engineering Electronics and Electrical.
  • 学位 Ph.D.
  • 年度 2007
  • 页码 190 p.
  • 总页数 190
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 无线电电子学、电信技术;
  • 关键词

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